01I4 THE AUTHORITATIVE MAGAZINE ABOUT HIGH FIDELITY DECEMBER 1975 47425 IMO 01111160 ille 0001101110111* WINO Baking with the Three -Point System Language of High Fidelity o C CI, C o In cr sr o r- o m e Ill CIC) CI. or I- .Z rei C cc D 02 ILI e IN ink z o o www.americanradiohistory.com AmericanRadioHistory.Com 75c 3 best le, get a Pioneer. Both units are even equipped with a strobe light directed at the strobe marks for easy viewing. Combine the best automatic features with manual operation Wh le many hi-fi enthusiasts demand completely manual turntable operation, there are many purists who prefer semi -automatic operation. Pioneer provides this extra convenience in the PL -55X and PL-15D/II. Both models incorporate automatic tonearm return and shutoff. When the record has finished playing, the tonearm automatically returns to the arm rest and the power is turned off. Automatic tonearm return and shutoff The PL-A45D completely automatic. You don't ever have to touch the tone is arm when you play your records. Fully automatic operation in single -play This 2 -motor model has a special precision gear motor to exclusively handle automatic tonearm lead-in, automatic return, automatic shutoff and repeat play. And when you prefer, you can switch to fully manual operation. The PL -71 and PL-12D/II, at both ends of Pioneer's turntable lineup, offer the total involvement that can only be attained by completely manual operation. Superb S-shaped tcnearms for better tracking The tonearm of every Pioneer turntable system is the S -shape design, for optimum groove tracking. Ml are statically balanced and all use adjustable counterweights with direct reading of "racking force. All have adjustable anti skate control and oil -damped cueing S-shaped tonearm tor better tracking for the gentlest application of stylus tip to record groove. Lightweght plug-in cartridge shells insure positive electrical contact and optimum stylus position and angle for lower distortion and reduced record wear. www.americanradiohistory.com AmericanRadioHistory.Com Unexcelled performance Still, all of these features and refinements do not guarantee the performance specifications of Pioneer's new turntables. Each tonearm and turntable platter combination is shock mounted in its specially designed natural grain base (with hinged dust cover). Precision machining of all rotational parts plus continuous quality control insure that each will meet or exceed its published spec fi cations --- a time honored tradition with all Pioneer components. Choice of the professionals Engineers, experts and enthusiasts agree: to get the best performance, select a manual turntable. And to get the best manual turntable, you need a Pioneer. Every Pioneer manual turntable offers a level of precision and performance unparalleled in its price range. And every one is a total system with dust cover and base designed for years of professional, trouble -free sound reproduction. U.S. Pioneer Electronics Corp.. 75 Oxford Drive, Moonachie, New Jersey 07074 / West: 13300 S. Estrella, Los Angeles 90248 / Midwest: 1500 Greenleaf, Elk Grove Village, III. 60007 / Canada: S. H. Parker Co. - - PL-15D/II For the ...,o, manual turntabl The manual turntable is rapidly becoming the first choice of h!i-fi enthusiasts everywhere. The reason why is quite simple. Today's enthusiasts are more knowledgeable, more sophisticated and more involved with their music. And only the manual turntable can provide the involvement and performance they demand. At Pioneer, this trend comes as no surprise. We have long recognized the superiority of the manual turntable. And long recognized a simple fact: a record changer in no way improves performance. It can detract from it. As a result, we now offer the finest and most complete line of manual turntables available. Manual turntables that are designed with the needs of today's hi-fi enthusiast in mind. Turntables that are engineered for precision response. When you get right down to it, good record playing equipment really has only two requirements: uniform rotation of a turntable, and accurate tracing of a record groove by a tone arm and its cartridge. Pioneer's engineers have long recognized that these requirements are best met by single -play turntables and precision engineered tonearms. Our five new belt -drive and directdrive turntable systems mean you needn t settle for the higher wow and flutter and the poorer signal-to-noise ratios (rumble) of record changers. Whether you've budgeted $100 or $300 for this vital element of your high fidelity system, there's a Pioneer turntable that outperforms any record changer in its price class. Consider the performance advantages Belt -drive, featured in Pioneer's PL -120/1I, PL-15D/II and PL-A45D, means smoother, more uniform platter rotation than can be achieved with typical idler-wheel/pulley arrangements normally found in record changers. Even changers Belt-drive for rumble free rotation Direct -drive motor reduces friction equipped with synchronous motors transmit vibration to the turntable platter.. This is picked up as low frequency rumble by the tonearm and www.americanradiohistory.com AmericanRadioHistory.Com cartridge. By driving the platter with a precision -finished belt, vibration is effectively absorbed before it can be translated to audible rumble. Pioneer's direct -drive models, PL-55X and PL-71 go even a step further in achieving noise -free, precision platter rotation. The DC electronically controlled servo -motors used in these models rotate at exactly the required 331/3 and 45 rpm platter speeds. Their shafts are directly connected to the center of the turntable, with no intermediate pulleys or other speed reduction devices. This means no extra friction producing bearing surfaces. Because of the unique technology embodied In these new, direct -drive motors, 'it's possible to control their speed electronically. This is more precise than any mechanical drive system. Both our PL -55X and PL-71 offer individual pitch control for both 331/3 and 45 rpm speeds. Their turntable platters are edge-fitted with stroboscopic marks, so you can adjust precise speed while a record is playing. Electronic speed adjustment for each speed For the best performance, get a manual turntable. www.americanradiohistory.com AmericanRadioHistory.Com There's a Pioneer turntable that's just right for your needs Model PL-12D/II PL-15D/II PL-A45D Manual Semi -Auto. Fully Auto. Belt Belt Belt Type Drive System Drive Motor 4 -pole synch. 4 -pole synch. 4 -pole PL -55X Semi synch. Speed Control S/N - uto. PL -71 Manual DiEect Direct DC servo DC servo ±2% ±2% Over 48dB Over 48dB Over 47dB Over 53dB Over 60dB 0.08% 0.08% 0.07% 0.05% 0.05% Static Bal. "S" Static Bal. "S" Static Bal. "S" Static '3al. "S" Static Bal. "S" 811/16" 81%6tß 811h6,, 81/ór, 83/4.. Turntable Dia. 12 12" 12" 121/4" 121/4" Priced Under*. $100 $125 $175 $250 $300 (RUMBLE) Wow & Flutter (WRMS) Tonearm Type Tonearm Length °The values shown are for informational purposes only. The actual resale prices will be set by the individual Pioneer dealer at Iles option. The PL -l1 includes a walnut veneered base: all other models include a base of walnut grained vinyl. CID Check No. 34 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com PIONEER when you want something better December, 1975 The Precision Est. 1917" Vol. 59, No. 12 Feature Articles Cleaning Instrument for Toddy's Styli 28 Miking with the Three -Point System Language of High Fidelity, Part XIII/Martin Clifford 38 Addenda to Annual Equipment Directory 117 Annual Index 80 Today's advanced styli are remarkably sensitive, and every Equipment Profiles manufacturer specifies that cleaning is essential for maximum performance. Introducing SC-I. The SC -I is a graceful walnut handle from MAGNIFYING which you can push a SIDE small tang. At the end -density a calculated of this tang is brush of black nylon with enough rigidity to clean waxy deposits-yet with enough "give" to eliminate cantilever damage. There is also a silvered mirror that magnifies the stylus, cantilever, and cartridge moum.ing for total BRUSH SIDE "successor to RADIO Radio Shack STA -225 Receiver/Leonard Feldman Technics T-400 Loudspeaker System/Richard C. Heyser 64 Yamaha CT -7000 FM Tuner/Leonard Feldman 68 Koss HV/1A Stereo Phones/C.G. McProud Nakamichi Reference Monitor Loudspeaker System/Richard C. Heyser 76 BGW 500D Basic Amplifier/Bascom H. King 46 54 72 Record Reviews Jazz & Audio In General 6 pickup system. All of This retracts into the walnut handle for elegant protection. The new SC -I for only $6.30, at audio wide that carry Discwasher products. Audioclinic/Joseph Giovanelli 12 Tape Guide/Herman Burstein 16 Behind The Scenes/Bert Whyte 22 Audio ETC/Edward Tatnall Canby 26 Dear Editor 98 Advertising Index perception of your specialists nation- The Column/Fred De Van & Jon Tiven Blues/Dan Morgenstern & John Lissner & Eric Henry 104 Classical/Edward Tatnall Canby 82 93 108 103 Classified Advertising What's New In Audio PUBLISHER Jay L. Butler EDITOR Eugene Pitts III MARKETING DIRECTOR Sanford L. Cahn ASSOCIATE EDITOR Edward Tatnall Canby DESIGN Janet Lee ASSOCIATE EDITOR Bert Whyte CIRCULATION MANAGER lean Davis EDITORIAL ASSISTANT Vickie Rock ADVERTISING PRODUCTION Lynn Lyons Contributing Editors: Herman Burstein, Martin Clifford, Fred De Van, Leonard Feldman, Martha Sanders Gilmore, Joseph Giovanelli, Richard C. Heyser, Bascom H. King, C.G. McProud, B.V. Pisha, Donald M. Spoto, George W. Tillett, Jon Tiven. AUDIO (title registered U.S. Pat. Off.) is published monthly by North American Publishing Co., Irvin J. Borowsky, President; Frank Nemeyer, and Jay L. Butler, Vice Presidents; R. Kenneth Baxter, Vice President/Production; Nate Rosenblatt, Promotion Director; Mary Claffey, Circulation Director. RATES-United States only: 1 year for $7.00, 2 years for $12.00, 3 years for $17.00; outside the U.S.: 1 year for $9.00, 2 years for $16.00, and 3 years for $23.00. Printed in U.S.A. at Columbus, Ohio. All rights reserved. Entire contents copyrighted 1975 by North American Publishing Co. Second class postage paid at Philadelphia, Pa. and additional mailing office. Back issues, $2.00 each. World Library Congress number: ISSN 0004-752X. Dewey Decimal number. 621.381 or 778.5. Cs dl$CWCISIi2R GROUP I)tSiCWAcHEFt, INC. 909 University Co(umb'a, Mo. REGIONAL SALES OFFICES: Jay L. Butler, Publisher and Sanford L. Cahn, Marketing Director, 41 East 42nd St., New York, N.Y. 10017, telephone (212) 687-8924. Jay Martin, 2525 West 8th St., Los Angeles, California, 90057, telephone (213) 385-2917. REPRESENTATIVES: Continental Europe: John Ashcraft, 12 Bear St., Leicester -Square, London W.C.2, telephone 9300525. For Benelux and Germany, W.I.M. Saunders, Mgr., Herengracht 365. Amsterdam, Holland, telephone 24.09.08. Japan: Japan Printing News Co., Ltd., No. 13.2 Chome Ginza Higasi, Chuo-ku, Tokyo, telephone 541-5795. AUDIO Editorial and Publishing Offices, 401 No. Broad St., Philadelphia, Postmaster: Send Form 3579 to the above address 10, www.americanradiohistory.com AmericanRadioHistory.Com Pa. 19108 ca flø// OC/øffiQfir trontormør r- (", 0 og/ Since introduction of the ESS amt ' tnree years ago. to world-wide acclaim as the first really new development in loudspeaker tecó-rc ogy in over 50 years, the Heil air -motion transformer has guided knowledgeable audicphilies to revu rcrizons of sound clanty. Now after two year's research th been further perfected to achieve virtually flawIless accwracy extraordinary loudspeaker class: r_. increased eve' a substantially A NEW Heil air -notion transforr-e- configuration that achieves greater vertical scund dispersion and permits penetra unified magnetization of each transformer with special equipment designed ald built by ESS expressly For this purpose , A NEW 12 inch high acceleration woofer manufactured by ESS under the strictest quality control, incorporates a 7.4 pound magnet assembly mounted on a rigid, open backed, cast aluminum frame Its cone is made cy a newly developed rubber impregnated Pulp and is oontoured to provide extreme :al midrange crossover de{ rition and clarity through the temperature point with dynamic, cvernang-free- _- ìs +rs voice coil asserbly allows mass with a suspended _-_e-:--s in conjunction A NEW aluminum frame 12 incdiaphragm of lamina:ed styrofc. _. by a compliant f-alf-roll foam sL. with the woofer to provide uset _ environment, extending as low ESSamt 1a reaches a -77 eve without full manufa:e r is so you car recreate e grandeur of a live performance prover never before experience._: of excellence, yourself at a fra- :who urderstands the loudspe air -motion transformer amt la clear as light. _ __ ¡nC. ES_ products 9613 oates d- ve soc - _ ._-),r ypicat lístenìrg - -.- - . ,erformance impossible -trot over all system - nent, immeciacy and - wily and dynam 7 _ _ _ _ this new ESS standard ESS dealer-a dealer -,:morrow. the ESS Heil cerience sound as -- =a- _ : fern;a 95827 avaobc in Cando: new th i e mflo brnr Hi a ïr- mücra tra ns I www.americanradiohistory.com AmericanRadioHistory.Com syst - First there was vacuum tube amplification then the solid state transistor and now... www.americanradiohistory.com AmericanRadioHistory.Com °. GL b t/1 2 +, >~ a, '`n a, rn >~ 0 cu 9 '^ O.0.. a, " R' .. b N O O c -, .3. + ^ s e, .. ., +U, re tU. 4--' O ö o Q..0 O +' 0 3 O ,tj O G1 ó >~ cn ce >~ .. a3, ai p s~x U... a, . >~ ß. ái 0a, D N n ^d 'C o O a, Q O +, w 0 - N ~ «S . Ú , O , cd a, -- r ' CCJ . u ti^ . >, .. '' bA c <, = Vi a, ei :. g .4 0. . ..` b .. L. O 2 .Sp. Ó o U ti z ":" F-' N bU f o, i . p Cf) Ú - y+ Ua, a, p (n .-- Q Ñ p .:. vUi % Ó r.=.1 , N. W a, w w rn v ó í-+ W CL) w y0. .:. 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U a, ,4.goco>~;o.= ce U -= ' O bA O b4 c cn ó O ' oE 4..: o c Uc en y., p_ o X E +, 0>~ ... w w a, ce c13 ao ce D, 0 ó ( a, g GL s~ cn a, } . ^o .SC ü p ,..; 0 O boo.b 72 >,boio obUá,OU ó ` cÿ Ñ s~ ce N bA .-U+ a, O a, ... Q >~ Q 3 1 1~ a' . __---. - f`, ` i sd,a..,-aw° a, -- a, (~ s~ a, b~.0 tee= a-.--3 > s0. ru 4.3 n .., g ÿ I c° . >~ 9, p cn o cn '' ñW a, -0 9 4. 3. a, í7 U O O +, cg a, bA ,+. s. cn oce www.americanradiohistory.com AmericanRadioHistory.Com cn cU, O 3 U c ái Ó +c:-,) E 0 5 '.. a, 3 >, t. > +, A a, 0 .,., p s~ bA+ bA cv,ó.s~ cà e U ^C o 1. s~ o iLu Check No. 19 on Reader Service Card a, w 1bvE-.,2-1a,Nvo a, 1. v, +, ..._.<1."8. . O o ó 3 + .-+ ;ccáoUpoco. aWp o ¢, . o a'.e -° á .,5a ,a0a,. b o,.a, Ue^ U° :^, p ,.~ , a: ,a O oato r, v ' C D, O L] .4-3 II 0 O s~ 3 w O Q 3 1. Ú >, c The $300 alternative. Audioclinic Joseph Gio wanelli 50- and 75-µS Pre- and De -emphasis Q. Please explain 50 -microsecond and 75 -microsecond pre -emphasis at the FM transmitter and 50 -microsecond and 75 -microsecond de -emphasis at the FM receiver. have noticed that some receivers and tuners have a switch for selecting either one. Does the 50 -microsecond de -emphasis circuit produce a brighter sound? /Larry Cook, Albany, Ga. 1 SAE MARK XVII Dual -Channel Equalizer Your tone controls are just not designed to compensate for Room acoustics DSpeaker placement DOld or bad recordings We built the Mark XVII Equalizer to solve these problems and more. These are some of the ways: Individual Octave Control for each channel DLong throw, oil -damped linear slide pots for greater accuracy DDual range operation (controls operate over either ±8dB or ±16dB) Plus DCapable of driving any system Low distortion-less than 0.03% THD and IM Low noise-greater than 90dB 35 -year parts and labor service contract SAE'S reputation as the finest manufacturer in the audio field You'd have to look a long time to find an EQ that delivers this much value. SAE innovation has done it. Components for the connoisseur. A. In FM broadcasting, as with tape and disc, we boost treble during production or broadcast and reduce it during reproduction to compensate for the boost. This results in less noise, but the amount of initial boost must equal the amount of later frequency cut or the frequency response will be altered. This is accomplished with a combination of a resistor and a capacitor. Any network of this kind will have a specific frequency boost or cut, starting at a given point and continuing at the given rate to the desired frequency. Beyond the designed -in frequencies, however, the network may not remain effective. Simply, when a capacitor and resistor are connected in series and a voltage is impressed across it, it takes time for the capacitor to charge. If the capacitor is already charged and then connected in parallel with the resister, it will take time for the capacitor to discharge into the resistor. These charge and discharge periods are said to be the "time constant" of the combination. Since several combinations of resistor/capacitor elements will produce this same time constant, the amount of boost or cut can be stated by using the time constant of the About The Cover: For this im- pressionistic cover depicting microphone use during WW II, we borrowed an RCA Model 44B mike from Bob Paquette. Introduced about 1937, most ra- Scientific Audio Electronics, Inc. P.O. Box 60271, Terminal Annex Los Angeles, California 90060 Please send me the reasons (including available literature) why the SAE MARK XVII Dual -Channel Equalizer is the "$300 Alternative." dio stations used the 44B the 40s, and it was throughout standard for network radio. NAME ADDRESS CITY STATE J components which make up the circuit, rather than the amount of boost or cut involved and at what frequency. Most FM stations use a 75-microgecond boost requiring 75/1,000,000 of a second to charge or discharge a network. (Actually, the formula is !based on a charge of 68 percent of the maximum possible charge that the capacitor can hold, and a discharge to 32 percent of the full original charge.) Using a 50-microsecond cut while !listening to a station broadcasting 'with a 75 -microsecond boost, the treble will be a bit brighter than otherwise. FM stations which broadcast n the Dolby system use a 25 -microsecond frequency boost at their trans- mitters for increased listener compatibility between Dolby and non Dolby equipped receivers. Loudspeaker Flux Q. Please explain what the word "flux" means, as applied to loudspeakers. Does more flux make a speaker sound better?-Richard McHale, Upper Darby, PA. A. Flux describes the amount of magnetism, in this case, in the voice coil gap of a loudspeaker. It is measured in oersteds (the old term was gauss). Generally, the more gauss present, the better. The amount of flux will affect the efficiency of a speaker and the amount of control which amplifier damping can exert on the motion of the speaker cone. Direct -coupled Amplifiers Q. What is a "direct -coupled" amplifier and how is it different from other amplifiers? Ronald L. Ambrogi Brooklyn, N.Y. A. A direct -coupled amplifier is one in which the signal is transferred from one stage to the next without coupling capacitors. Because capaci If you have a problem or question on audio, write to Mr. Joseph Giovanelli, at AUDIO, 401 North Broad Street, Philadelphia, Pa. 19108. All letters are answered. Please enclose a stamped, selfaddressed envelope. 71P Check No. 41 on Reader Service Card 6 AUDIO DECEMBER, 1975 The Du cassette deck The first; high-performance precision deck with automatic reverse. Automatic reverse has not been generally associated with high quality in tape recording. But as Dual has long proven with automatic turntables, convenience can accompany precision performance. Since the primary reason for selecting a cassette deck is its performance quality, let's consider this first. With standard tapes, the frequency response of the Dual cassette deck extends from 20 to 14,000 Hz at -±1.5 dB and to 17,000 Hz at ±3 dB. Wow and flutter (DIN weighted) is 0.07%. Harmonic distortion is less than 1.5%, and signal-to-noise is greater than 50 dB; 59 dB when the Dolby system is switched in. The motor is Dual's well-known Continuous-Pole/synchronous motor which has long proven its reliability in our finest automatic turntables. A precision -ground flat belt transmits power to the capstans. A separate drive belt powers tape take-up. The VU meters are ballistically damped to provide precisely the rise time and overshoot characteristics specified for broadcast quality meters. Now for convenience. Automatic reverse lets you double the playback time of any cassette. Continuous -play lets you hear both sides over and over until you shut the machine off. Recording is bi-directional, eliminating the need to turn the cassette over at the end of side one. Rewind time for a C-60 cassette is 60 seconds flat. You can see the rest for yourself in the photograph. This cassette deck is also typically Dual in appearance: clean, functional, uncluttered. If you own a Dual turntable, you've come to appreciate these qualities. And if you're about to own a cassette, you'll appreciate some additional niceties of the Dual. The meters tilt up for viewing from across the room. The viscous -damped cassette holder rises smoothly and silently when the eject button is pressed. The built-in Dolby test oscillator precisely adjusts for any tapes, today's or those of the future. In short, this cassette deck was designed with the same philosophy that Dual has espoused for years: the most serious audio equipment can also be the easiest and most convenient to use. Price: $450. United Audio Products 120 So. Columbus Ave., Mt. Vernon, N.Y. 10553 Exclusive U.S. Distribution Agency for Dual Check No. www.americanradiohistory.com AmericanRadioHistory.Com 11 on Reader Service Card Dual tors introduce phase shift, their elimination removes this problem. Their elimination also saves parts and therefore lowers cost a bit. The disadvantage is that the voltage of the early stages affects the operating point of the later stages. A failure in any of the early stages may bring about failure of the later stages. This can prove costly. Fortunately small -signal transistors and ICs used in these early stages are not highly prone Equalizers of Q. Please explain the use equalizer in a four -channel component system. Are two equalizers is the equalizer connected within the system? Some manufacturers claim their equalizer enables the user to increase the volume of certain instrumental sections and enhance the performance of a given soloist. ff this claim is true, how does an equalizer accomplish this?/Roy Clark, Chicago, Ill. A. Amplifiers have bass and treble tone control. They enhance the sound quality of the system by enabling the listener to add or remove necessary? Where to failure. Direct-coupling is widespread in transistor amp drcuitry. It was used only very occasionally in tube amp circuitry. Ever wish yoj could add a lit -le more rook ton poptLre? Or a bit more pizzaz to some jazz? I: s easy with .aensen's all near OPC speaker systems. Each comes with s»clusive front -mounted Optimum Perfo-mance Controls that allow you to acj_st speaker frequency response to an.,.dnd of music cr mood. No mater wig type of listening enviroiment you re -n. One thing that never changes-the rich crystal -deer Jensen sound. No matter hcw you set your OPC controls. yoL'r3 going to hea- sound quality you car': find in any comparably priced speeler systems. That's because hside wee placed featL res like Fiexair` woofeft suspension for Cis ertion-free bass. Sonodome° ultra teeter for imprwec high frequency res_onse. And me h more. Mane Jensen CRC speakers a part of yea- system. When you add hese new Jensens to ycu new or social ng component systsT. it's not only coirg to add quality to tiesound. It's gzirg to add a little bit of See and hear 11-e new Jensen OPC speakers for yojrself. For a free catalog and listinçofJensen dealers in yci area, w-i_e: Jensen Sound Latoratories, 4310 Trars World Road, Schiller Park, Ill ncis60176. JENSEN till SOI an LABORATORIES Division of Pemcoe Inc. Erhll er Park. Illinois .0176 bass or treble from specific program sources. Such controls are a form of equalizer. Today's "full" equalizers are more sophisticated. Rather than dividing the audio spectrum into just two segments, these devices take narrower segments of the response and boost or cut them. A segment usually is one octave wide, but can be narrower depending on the design of the equalizer and the desired uses. Considering we can hear over a frequency range of perhaps 10 octaves, we might have 10 separate tone controls for each channel. If we divide the spectrum into even smaller segments, we would have even more controls and, in so doing, can correct peaks or dips in room or speaker response. But this flexibility brings with it the complications involved in trying to use all these controls effectively. If an equalizer can correct for problems in a stereo or mono system, it can also be used successfully for fourchannel sound systems. It would probably be easiest to install the equalizer after the matrix decoder on a matrix four -channel system. For discrete channels, it would be placed between the discrete source (decoder, tape machine, etc.) and the individual channel inputs. Most equalizers sold are stereo units. Such a unit can be used to con- trol the equalizations for two channels, requiring two such units for a four -channel unit. Some equalizers have a set of controls which affect both channels at one time. But if each channel has its own set of controls to adjust for room acoustics, more flexibility is available. Some equalizers are sold as single -channel units. You would then need four of them, one for each channel. Equalizers can occasionally be used to increase the volume of certain instrumental and vocal timbres, though this is not always successful. if an instrument has most of its acoustical energy concentrated in a certain portion of the frequency spectrum, the equalizer can be adjusted to bring up only the portion containing that instrument. Conversely, an instrument can be subdued by turning down its portion of the spectrum. But if more than one instrument or vocalist shares a portion of the spectrum, everything will be affected when that portion is adjusted. Equalizers can totally destroy the sound of a system when used improperly. The highest quality sound system can be made to sound like a table radio if the equalizer is not adjusted properly. AUDIO DECEMBER, Check Yo. 21 on Reade- îervice Card www.americanradiohistory.com AmericanRadioHistory.Com 1975 "The Som TC -756 set new records for performance of home tape decks:' (Stereo Review FebruarY 1975) Hirsch -Houck Laboratories further noted, "The dynamic range, distortion, flutter and frequency -response performance are so far beyond the limitations of conventional program material that its virtues can hardly be appreciated:' The Sony TC -756-2 features a closed loop dual capstan tape drive system that reduces wow and flutter a minimum of 0.03%, logic controlled transport functions that permit the to feather -touch control buttons to be operated in any sequence, at any time without spilling or damaging tape; an AC servo control capstan motor and an eight -pole induction motor for each of the two reels; a record equal- three -head configuration; and sym phase ization selector switch for maximum recording that allows you to record FM record and playback characteristics with matrix or SQL` 4 -channel sources for either normal or special tapes; mic playback through a decoder-equipped attenuators that eliminate distor- 4 -channel amplifier with virtually nontion caused by overdriving the micro- existent phase differences between phone pre-amplifier stage when using channels. The Sony TC -756-2 is representsensitive condenser mics; tape/source monitoring switches that allow instan- ative of the prestigious Sony 700 Series taneous comparison of program source -the five best three -motor 101/2rinch to the actual recording; a mechanical reel home tape decks that Sony has memory capability that allows the ever engineered. See the entire machine to turn itself on and off auto- Sony 700 Series now at your nearest Superscope dealer starting at matically for unattended recording. In addition, the TC -756-2 offers 15 $699.99. and 71/2 ips tape speeds; Ferrite & Ferrite 2-track/2-channel stereo SONY Brought to you by SUPEßSCOPE. the a trademark of CBS, Inc. ©1975 Superscope, Inc., 8150 Vineland Ave., Sun Valley, CA 91352. Prices and models subject to change without notice. Consult Yellow Pages for your nearest Superscope dealer. *SQ is www.americanradiohistory.com AmericanRadioHistory.Com You're looking at our attitudes 4. -.,-,,., ii,'íízr":iiii.':k?;iï,iiiï:Y//1111ir1i//;Yiiii111iiliiriii!1/r?!!11!!!i üï f NU B Rabco ST -7 0 0 O e8- 430 e 0 0 0 0 e e e A401 We've been at the business of high fidelity for a long time. And still, every so often we ask ourselves, "What's it all about?" For us, it's certainly not about mass production, nor about squeezing products into traditional "price points". What we are about is to find, without qualification, the best way to reproduce music in the home. Of course we've had our disappointments. We remember a "shelf" unit that couldn't fit on any shelf known to mankind. But then there have been our triumphs. We believe the products in this advertisement are the finest expressions of the attitudes that motivate us. They are diverse, but consistent with our commitment to bring the highest quality to every function of music reproduction. The new Harman/Kardon Rabco ST-7 turntable is an excellent example. It plays a disc in precisely the way the cutting head made the master record. The arm, carried by the remarkable "rolamite" bearing, moves across the disc in a straight line. The result is a cascade of zeroes. Tracking error? Zero. Skating force? Zero. Stylus overhang? Zero. Horizontal friction? Zero. Vertical friction? Zero. Simply stated, the new ST-7 provides a way of playing music in the home that obsoletes conventional pivoted arm turntables. Diverse and consistent. The Citation 16 amplifier is a remarkable synthesis of brute force, technological precision and sonic sensitivity: awesome power with flawless performance. When measured by the criteria that together most accurately predict musical results -square wave response, slew rate and rise time -Citation 16 is without peer. The excitement we feel at Harman/Kardon these days is in part due to the reaction from audiophiles who have experienced Citation 16. 'r.'3iru. 0 0 e e ® Citation 16 Diverse and consistent. The ST-7 and Citation 16 expand the boundaries of state-of-the-art. The resulting new technology is soon incorporated in other products. The new A401 integrated pre-amplifier and power amplifier does not produce the absolute power levels of Citation 16. But its square wave response, slew rate and rise time reveal its genealogy. We can conceive of no better recommendation for the first time "investor" in high fidelity. Diverse and consistent. As the 430 receiver vies for visual attention on your dealer's shelf, it may seem almost diffident. Don't believe it! For within its graceful contour lies such power as to meet truly de- manding dynamic conditions -without compromise of sound quality. The source of the 430's energy is not the conventional single power supply. It has two discretely separate power supplies -one for each channel. Consequently, no matter how much energy is called for by 'dynamic music passages, performance of one channel is not affected by the other. The features of the amplifier section (twin power, square wave response, phase linearity, instantaneous transient response) and many elements of the tuner and preamplifier sections are inherited from our Citation series of components. There is simply no comparison between the 430 and other modestly priced receivers. Its performance can be appreciated most by direct comparison with expensive individual components. The 430 demonstrates, upon the very first hearing, that quality need not be sacrificed to achieve the economy of size, convenience and price. Of course you're looking at new high fidelity instruments. But the attitudes with which they were conceived and built are their very essence. We'd like to tell you much more about them -directly -without circled numbers or coupons. Write to us. We'll respond promptly. Harman/Kardon, 55 Ames Court, Plainview, N.Y. 11803 harma n/ ka rdon www.americanradiohistory.com AmericanRadioHistory.Com Harman Kardon Canada Ltd Montreal www.americanradiohistory.com AmericanRadioHistory.Com THE FIRS!! Tape Guide PREAMP BY BGW Herman Burstein THE BGW 202 HAS- Dual discrete OP amp phono stage for unprecedented accuracy Active tone controls using sliding step switches Active 18-dB/OCT. High and low pass filters Two phono inputs plus accessory socket for moving coil pre-preamp converter Separate power amp switching Remote AC switching unit accessory available Guaranteed specifications: Phono stage: Gain=42-d B, ±.25 -dB of RIAA, S/N=82-dB,THD=.01%. Tone controls: Active baxandall controls add virtually no distortion. ±18 -dB at 50 -Hz and 15 -kHz in 3 -dB steps. High and low pass filters: Active 3-pole, 18-dB/OCT. Low frequency at 40 -Hz, high frequency at 12 -kHz. Maximum output voltage: At line output, 8 -volts RMS into 600 -ohms (+20dBm). Phono at tape output, 10 -volts RMS into 5-kohms. Rated output, 4 -volts RMS into 5-kohms. Total harmonic distortion: Less than .01% at rated output, 20 -Hz -20-kHz. Write for the location of your nearest dealer. BGW Systems P.O. Box 3742 Beverly Hills SYSTEMS in Canada. CA 90212 (213) 973-8090 Recrion, Limited 105 Denison St. Markham, Ont. (416) 495-0880 Check No. 4 on Reader Service Card Tape Recording Problem Q. The quality and volume of the sound from tapes I record on my TEAC 6010 are much lower and poorer than the program material, even though the VU meter shows proper deflection. When I play tapes on other machines the sound is OK. What can the trouble be?-P. Y. Kosol, Winnipeg, Canada. A. Your VU meter may be mis calibrated, causing it to give too high a reading, thus leading you to record at too low a level. Or you may have insufficient bias current feeding to the head, due to a defect in the bias oscillator and the record head, or to a misadjustment of the control which sets the bias current. If your recordings also include excessive high frequencies, you probably have insufficient bias. Another possibility is that there is a defect in the record electronics following the point where the signal is tapped off for the VU meter. This could cause insufficient record signal at the record head. Q. Where can I get a book telling me how to get the best results from my tape recorder? The instructions which came with my Radio Shack 909 are very brief. I also need to know what is correct routine mainL. 1 Crown 5X824 tape deck to my system. This machine has excellent specifications, but since money is no object am considering adding the Advent Dolby B unit to it. Will I be helping or hurting the sound otherwise obtainable with the Crown?-Lee A. Swoboda, Long Beach, California. A. The Advent should not degrade the quality of the recordings you make with the Crown, but it's not likely to improve them audibly at the higher speeds. If you use the Crown at low speeds, there should be some improvement. The rule is, the better the tape machine to begin with and the higher the tape speed, the less improvement Dolby will make. Cassette machines, running at 1-7/8 ips, and with very narrow tracks, four across a 1/7 -in. wide tape (!), get much more help from Dolby noise reduction than do open -reel machines using 1/4-in. tapes, at higher speeds. 1 Which Tape to Use? Tape Recorder Care and Operation tenance.-A. Adding Dolby to O -R Tape Deck Q. am considering adding a Hall, Portsmouth, N.H. A. Every tape recorder maker know of produces a service manual for his machines, either available free or for a dollar or two (although service manuals for very new models sometimes are not available for some months after they are first on the market). For books dealing with tape recorder use and maintenance, go to the largest parts distributor near you. If none are within your area, write to: (1) Howard W. Sams & Co., Inc., 4300 West 62nd St., Indianapolis, Ind. 46206, (2) TAB Books, Blue Ridge Summit, PA. 17214, (3) Audio Book Club, 134 N. 13th St., Phila. Pa., 19107. Sams may be best for specific service information on a particular machine. I Q. I own a Sony TC630 machine. I'm getting into some serious recording using Sony FCM-22 mikes. I understand that Sony adjusts bias to its own tapes. Until now I have preferred to use Audiotape. Do you think I should either use Sony tapes, which are more expensive, or readjust the bias to Audiotape?-Neil Davidson, Stamford, Conn. A. Are you sure that you must have bias adjusted in order to use Audiotape? If bias does indeed have to be changed, consider the following. Unless you have the instruments and technical knowledge, the adjustment must be made by a competent technician. His charge will be between $15.00 and $25.00, perhaps more, and this could pay for the price differential of quite a number of reels of 49, tape. a problem or question on tape recording, write to Mr. Herman Burstein at AUDIO, 401 North Broad Street, Philadelphia, Pa. 19108. All letters are answered. Please enclose a stamped, self-addressed envelope. If you have AUDIO DECEMBER, 12 www.americanradiohistory.com AmericanRadioHistory.Com 1975 60% of BOSE Owners Changed hile we enjoy talking about the technology that distinguishes the BOSE 901eand about the urprecdented series of rave reviews by leading critics, he purpose of an advertisement is to increase sales by introducing more people to the product. surprising result of a customer survey changed our mind as to the most effective use of advertising funds. It revealed that 60% of the people who select the BOSE 901 do so at the recommendation of a 901 owner! This told us that the best advertisement is the product, and the best salesman Is the enthusiastic owner. A Our Mind We concluded that an excellent use of advertising funds would be to help set up an absolutely phenomenal music system in as many owners' homes as possible. Known as the SUPER BOSE SYSTEM, it consists of the 1801TMpower amplifier and two pairs of 901 speakers. One pair of 901s is placed to reflect sound off a front wall, and the second pair reflects off side walls, producing sound with spatial realism and presence that is simply astounding. 111111111111111111.1111111111111111 Our program in setting up these systems in owners' homes is to provide the SECOND PAIR OF 901s FREE to all those serious enough to purchase a component system consisting of the 1801 amplifier and a pair of 901s. We have allocated sufficient advertising funds to cover all purchases made from October 15, 1975 to January 15, 1976. that the SUPER BOSE SYSTEM is the best music system available today. We believe And we believe that its owners will be the best BOSE salesmen tomorrow. One equalizer is required for the Super Bose system, and accordingly the second pair is supplied without equalizèr. This offer is good an continental U.S.A., Alaska and Hawaii only. 901 cabinet is walnut veneer. .11117.574E-7 M :ntain, Framingham, MA 01701 www.americanradiohistory.com AmericanRadioHistory.Com Four questions you multiple -play Does it perform as well as any single -play turntable? There are some who believe that a single -play turntable is somehow inherently better than a multiple -play unit. All right-the Z2000B is a single-play turntable. Its capacity to function as a multiple -play unit offers convenience with no compromise of performance. The automatic mechanism which gently indexes the arm, lifts it at the end of play, returns it to the arm rest and shuts off the motor-is completely disengaged during record play. A 2-position control sets the proper vertical tracking angle for single or multiple play. The Z2000B can truly be called the automated, single -play turntable with multiple -play capability. 2 Does it have belt -drive and variable speed? 3 Does it handle records gently? 4 Garrard engineers have attained remarkable results by combining the world famous Synchro-Lab motor and an inventive belt/idler drive combination. A 5 lb., die-cast, dynamically balanced platter is rotated via a flexible belt. Not only are the tiniest fluctuations of speed smoothed out, but an extraordinary -64dB rumble is only one example of the impressive specifications achieved. A variable speed control corrects out-of -pitch recordings and an illuminated stroboscope provides optical confirmation. The Z2000B combines all of these elements to achieve the main goal of Garrard engineering: superior performance at reasonable cost. All responsible turntable manufacturers are concerned with protecting your records. With Garrard, it's an obsession. The Z2000B boasts an array of features designed solely to prolong the life of your records. In addition to the exclusive, articulated tonearm, it incorporates an exceptionally accurate magnetic anti-skating device. Cueing is viscous damped in both directions. The ingenious built-in automatic record counter keeps track of how many LP sides the stylus has played. And unlike some of the highest priced changers that support records only at the center hole, the Z2000B supports them at the hole and edge, and the release mechanism operates at both points. Protection for your records indeed! Does it eliminate tracking error? The grooves of a record are cut by a stylus that travels in a straight line. Conventional playback tonearms move in an arc. The difference between these two paths is called "tracking error:' Simply stated, tracking error launches a cycle of distortion and record wear. In good design, the error is averaged over the record so that distortion is minimal. But such compromise was unacceptable in the Z2000B. What Garrard engineers did about it was summed up by High Fidelity Magazine which described the Zero Tracking Error Tonearm as `:.. the best arm yet offered as an integral part of an automatic player:' The Z2000B is the only automatic turntable in the world without tracking error. For your free copy of the New Garrard Guide, write to Garrard, Division of Plessey Consumer Products, Dept A, Plainview, New York 11803. Check No. 16 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com must ask about any turntable. The Garrard Z2000B.Yes.Yes.Yes.Yes. atiha.td $229.95 The Automatic Choice www.americanradiohistory.com AmericanRadioHistory.Com Behind The Scenes Bert Whyte calendar that December for its appointed round, and the end of the year is nigh, and it is time for the rotund little chap in the red suit and "Ho, Ho, Ho" and all that jazz. How did the hi-fi industry fare in 1975? It certainly wasn't "the best of all years," but it was a great deal better than most people expected. That the industry weathered this recession year as well as it has is continuing proof of its basic strength. Yet there were warning flags flying in 1975, and the industry will jeopardize this strength if these signals are ignored. In 1974, the FTC ruling on power amplifier rating, with its controversial "burn -in" provision, became law. That it caused consternation within the hi-fi industry is to put it mildly. Audio engineers en masse, led by colleague Len Feldman, Chairman of the IHF technical committee, denounced the "burn -in" period as "harmful" and not "relevant to the normal mode of amplifier usage in the home." In spite of documenting to the FTC that compliance to the "conditioning" provision would in most cases require technical modifications to the amplifiers that would ultimately mean higher costs to the consumer, the FTC has barely budged from its position. It appears the FTC knows that they made a bad ruling and in fact have been looking for a way to retreat from their position without causing themselves too much embarrassment. What we must remember is that part of their intransigence is due to the fact that they consider that they gave ample time for the hi-fi industry to study the powISEE BY my has arrived er amplifier ruling and suggest possible changes or amendments. It must be admitted that by and large the industry ignored this matter, and when they finally did become aware of the perils of this ruling, it was already too late. The latest word is-and this is only at the "opinion" level, not the full "promulgated ruling" level-is that the FTC will allow an amp's thermal 16 cutout to operate during the preconditioning until the required one hour burn -in time has been accumulated. have a feeling that the power amplifier ruling of the FTC is just the tip of the iceberg. Government agencies are always trying to perpetuate themselves and justify their existence. Inevitably, other aspects of the advertising and promotional activities of the hi-fi industry will come under FTC scrutiny. Now please don't misunderstand me ... I'm not saying the hi-fi industry has anything to hide or is in any way I engaged in any chicanerous practices. In fact, as have said many times before, the industry is virtually unique as one of the last bastions of the "good value for the money" philosophy. Nonetheless, it is conceivable that the wording and even the validity of product specifications and performance parameters might be questioned. Let us not delude ourselves that manufacturers do not interpret specifications to their competitive advantage in their advertising. This is, of course, entirely due to a lack of hi-fi industry standards for the various aspects of product performance. One cannot blame the manufacturer for taking the "leeway" this affords in quoting specifications. For some time now, there has been a groundswell of opinion in favor of the establishment of performance standards for all audio equipment. In view of the unfortunate experience with the FTC power amplifier ruling, the industry should act now to establish these standards. The IHF could be the regulatory body for such standards and, as noted previously, has already in existence a technical committee which could initiate this program. It is realized that there are many types of audio components, with many different performance parameters and formulating standards for them will be technically difficult and a most arduous task. However the need is obvious, and the time for action is now, if further brouhahas with the FTC are to be avoided. I Writing in the September, 1975 edition of Radio -Electronics, Len Feldman points out some of the "inconsistencies" in the quoting of signal-tonoise ratio figures for phono pre amps and turntables. For example, if a phono pre -amp stage has a true input sensitivity of 2 millivolts at 1 kHz with the usual test procedure, the S/N ratio may turn out to be -55 dB, and be accurately quoted as "-55 dB below 2 mV." However, for some years now, in this country and abroad there seems to be a "tacit agreement or acceptance" among manufacturers to the use of a "reference" phono input sensitivity of 10 mV. Thus, while the manufacturer states the true input sensitivity (i.e. 2 mV), they quote the S/N ratio at the "reference" input of 10 mV, which magically improves the S/N ratio by 14 dB and enables them to state the specification as "-69 dB below 10 mV." While this may seem a deplorable practice, most of the manufacturers do it in self-defense, much in the same fashion of using the term "rms" in rating power amplifiers, in which the use of rms is not really relevant. Len also relates a similar situation in the manufacturers specifications for the rumble content of turntables. There are four different methods of measuring rumble ... the NAB, CBS/ARLL, and the German DIN A (unweighted), and DIN B (weighted). (And don't forget the CCIR standard, Bert.-Ed.) In all of these methods, the turnover frequencies are different, the rate of attenuation for the filters is different, and they do not employ the same "reference" frequency or amplitude in establishing the "0 dB" point, below which the rumble is measured. Thus, depending on the actual distribution and amplitude of the rumble frequencies in a turntable, the manufacturer can choose from among the four methods, that which gives the highest "number" and therefore the most favorable rumble specification. Another provocative and informative article on the use and abuse of test procedures and the interpretation AUDIO DECEMBER, 1975 TWICE AGAIN, HISTORY REPEATS ITSELF. Carrying on the innovative tradition of our almost ninety year involvement in music, Yamaha announces a double breakthrough in all-FET technology. Yamaha's B-1. Yamaha's C-1. At $1800, you've never seen a preamplifier like this before. It's so different we call it the Master Control Center. You'll call it well worth waiting for. From input to output, it's the first to use advanced FET's exclusively throughout the signal path. Yamaha's C-1 is made for perfectionists who appreciate the superb clear tonality and exceedingly low distortion that only FET's can bring. For advanced audiophiles who want maximum output), the C-1 features a unique four -gang volume control that the complete control over literally thousands of audio variables that only Another unique feature that sets the Yamaha C-1 Master Control Center apart from other so-called state -of -theart preamplifiers: Six-position selectable phono impedance that allows your cartridge to be the most advanced circuits and features can offer. A built-in oscillator. Consider the C-1's unique built-in oscillator with level control, a professional test instrument that's usually found only in sophisticated audio labs. By generating both random "pink" noise as well as the four most useful test tones (70 Hz, 333 Hz, 1 kHz and 10 kHz), the C -1's oscillator can be put to a variety of tasks: Determining the precise phono impedance loading, checking the frequency response of speakers, A -B speaker comparisons, setting up a tape deck, balancing the output level of an entire system, and balancing room acoustics. You'll discover more and more uses as you go along. (A word of caution: because the C-1's oscillator can be used externally, all your audiophile friends will want to use it to test their own components.) Where most other manufacturers use a negative feedback design in their phono equalizer amplifiers, Yamaha specified the more sophisticated passive interstage equalizer (CR -type). The results were worth it: Greater stability, lower distortion, superior tonality. In our all-out effort to reduce noise at all preamp output levels (not just at simultaneously adjusts inputs and outputs. You're totally in control. With the C-1's selectable equalization controls for presence and acoustic balance, you enjoy the equivalent of a separate equalizer. For those occa- sions when you don't want to use equalization controls, the C -1's special circuitry lets you bypass them completely. precisely loaded for optimum high frequency performance. The Yamaha C -l's absolute control over sound also includes a pair of extra wide -range (-50 db to +6 db) peak reading meters. Electronic damping provides both faster peak readings and slower decay, assuring precise monitoring. You can also use the C-1's meters to monitor any external component that doesn't have meters. Writing in Audio about our unique metering system, Bascom H; King stated: :..by far the most accurate and meaningful of any meter set-up seen thus far: Individual level controls let you balance the input from all signal sources, except the tuner. (Yamaha's companion tuner, the CT-7000, has its own variable output level adjustment.) So the volume level stays the same when you switch, for example, from tape to phono, tuner to aux, etc. And there's more. Enough that once you hear the Yamaha C-1, you'll never be satisfied with another preamplifier again. At $1600, it's already redefined stateof-the-art amplifier performance in a lot of people's minds. Yours might be next. Revolutionary Vertical-FET design produces a completely different kind of sound. Clean, open and transparent. With a richness that goes beyond the best vacuum tube amplifiers. And, up to now, unavailable. Worth the wait. As late as a few years ago, there existed only two types of transistors: bipolar and horizontal FET. Each operated in a completely different manner. The bipolar device uses input current to control output current. On the other hand, the horizontal FET uses input voltage to control output current-a more suitable audio technique that's quite similar to vacuum triode tube design. (Both use input voltage to control output current; both have sharp cut-off characteristics which eliminate high-order harmonics and notch distortion.) Only there was a small problem. Because current passage was restricted to a single path, the horizontal FET didn't produce enough power to be used in the output stages of a power amplifier. Then, in 1971, Prof. Nishizawa of lbhoku University drastically changed the FET's internal structure. The shape of the voltage -controlled constriction was altered to let the current take an almost infinite number of paths. And so, the Vertical-FET was born. During the past three years, working exclusively with Prof. Nishizawa, Yamaha's engineers have brought the Vertical-FET to the forefront of audio technology, where it serves as both driving and output devices in our new B-1 amplifier. The B -1's rated 150 watts per chan - YAMAHA International Corp., P.O. Box 6600, Buena Park, Calif. 90620 Check No. 53 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com nel (20 Hz to 20 kHz, less than 0.1% THD) are produced by only two Vertical-FET output devices per channel. Compare that with the minimum of six to eight output devices per channel found on most other amps! Yamaha knows that fewer output devices minimize the distortion caused by out -of -balance output devices during transistor switching cycles. And maximize tonality. People are talking. Here's what Julian Hirsch of Stereo Review had to say about the power handling capacity of Yamaha's new Vertical-FET: "Each of the FET's is about the size of an ordinary power transistor, but it can dissipate 300 watts!" Audio's Bascom H. King observed that the B -1's power output at visual onset of clipping for an 8-ohm load was 220 watts -46% over spec! So you can see that our 8 -ohm rating of 150 watts is quite conservative indeed! Because the B-1 is used as a reference amp by many of our dealers, we supply an optional control unit that can A -B up to five pair of speakers and balance them for efficiency at the head amp. Without the insertion of T -pads that degrade low -end response by decreasing damping characteristics. It's called the UC-1. It costs $250. And you don't have to be a Yamaha audio dealer to own one. Besides speaker switching, the extra wide -range peak delay meters, with faster peak and slower decay like those on the C-1 (but calibrated in both dB's and watts of power output), offer an extremely precise monitoring capability to your system. Yamaha's C-1 and B-1. $3650 the pair, with the UC -1 control unit. After you hear them together, you'll never be satisfied with anything less. UC -1's The CROWN VFX-2 electronic crossover Commercial sound contractors across America have been asking for an electronic crossover for use. on sophisticated sound installations. There's no more waiting. And the Crown VFX-2 embodies all you expect in high quality and performance capabilities from the people at Crown. Only the Crown VFX-2 electronic crossover will give every installation maximum versatility. Such flexibility for so little cost. And never before has an electronic crossover been offered that can be easily and readily adjusted with front panel controls. Tunable from 20- to 20,000 Hz, this solid state component is compatible with 600 ohms loads and up, and features both balanced and unbalanced inputs and outputs. Overall noise and distortion are extremely low. IM distortion is less than 0.01% at rated output, and noise is more than 97dB below rated output with open inputs. Providing either crossover or bandpass functions, the VFX-2 utilizes two continuously variable filters per channel, and filter roll -off is at a fixed 18 dB/octave. Applications include stereo biamping, mono tri-amping, and combining the bandpass filter with the normal two-way crossover on a mono signal. And all connections are quarter -inch phone jacks for positive electrical contact. The VFX-2 is designed for standard 19" rack mounting and measures in at 31/2" high by 53/4" deep and includes a clear plastic cover for protecting control settings. of manufacturers specifications appears under the title of "The Specification Says ..." by Hugh Ford, writing in the September, 1975 issue of that most estimable British journal, Studio Sound. Mr. Ford examines in depth, measurement techniques for frequency response, S/N ratio, input and output sensitivities, total harmonic distortion, and intermodulation distortion, as applied to various audio equipment and warns us about interpretive pitfalls. Speaking of Studio Sound, if you are into professional audio or if you are a very advanced audiophile, this is a "must" publication providing comprehensive coverage on audio subjects simply not available elsewhere. Recent issues on quadraphonic sound and ambisonic recording were real gems. If you want to subscribe to Studio Sound, which is published monthly, it will cost you the dollar equivalent of 4 pounds, 20 pence; write to the magazine at Link House, Dingwall Avenue, Croydon CR9 2TA, England. The authors of the aforementioned articles have given us very cogent arguments on the need for the establishment of internationally accepted standards of audio measurement and performance. Needless to say, this has been true for many years ... let us hope that we will have an end to procrastination and assorted excuses, the "backing and filling," and finally get some action. As mentioned at the beginning of this article, it seems that Christmas is upon us. Although I may be stretching the term a little, herewith some "su- per stocking stuffers" that should gladden the Christmas spirits of any audiophile.... With the winter months ahead of the heat will be turned on in homes and apartments (Allah willing) and the humidity will drop, and all that dry air will bedevil our vinyl records with static. The use of a humidifier helps some (supposed to be better for your health, too) but have been testing a Jim Dandy gadget that positively eliminates the static charge on your precious discs. It is called a Zerostat, and looks at first glance to be similar to a white plastic toy water pistol, with a large, elongated metal trigger. The action is quite mysterious, and the construction of the unit does not encourage explorations into its innards. However, as far as can determine, it seems to be some sort of "strain gauge" affair. In any case, it takes a fair amount of pressure to squeeze the trigger. The instructions us, I Write for complete specifications. crown BOX 1000 ELKHART, IN. Check No. 6 on I state that you must exert a slow constant pressure on the trigger. If you are too fast you will hear a "click" and the desired reaction will not happen. What is happening is that when you fully depress the trigger in the proper manner, a stream of positive ions is flowing from the tip of the gun. By then releasing the trigger in the same slow controlled motion, negative ions are produced. To test the Zerostat, I briskly rubbed a record with a dry cloth, and created enough static that when I passed the disc just above my arm, the hair on my arm was attracted to it. Then, holding the Zerostat about 4 in. above the center of the record went through (as per instructions), the squeezing operation. When I passed the now "treated" disc over my arm, could neither observe nor feel any attraction ... the static charge had been completely removed. The Zerostat is a British product and is imported by the Discwasher Company. It retails for $29.95. In my view, when you use Dr. Bruce Meier's Discwasher system, which really does a superlative job of cleaning a record, followed by a treatment with the Zerostat, your record will be in pristine I I condition. For those fortunate audiophiles who own professional tape machines, they will ¿ppreciate the AKG K-140 headphones, whose 600 -ohm impedance allows you to hear a signal at a good level from the headphone jacks of the tape machine amplifier. Add an ingenious headband that easily adjusts to different shaped "noggins," a light weight of 6 oz., and an extremely smooth and extended frequency response, all for around $34.00, and you have a worthwhile gift. There are other phones in the 600 -ohm category, but I happen to like the combination of features on the K-140. Another stocking stuffer that would be a welcome gift for the tape recording enthusiast is a professional quality alignment tape, such as those made by Magnetic Reference Laboratory, on which reported some months ago. Price, around $30.00. Lastly, the well-known CBS Labs Technical series test records have recently been updated and remastered. There are nine of them covering such areas as square wave, tracking and intermodulation tests, wide range pickup test, RIAA pink noise acoustical test, RIAA frequency response, stereo frequency test, etc. For the serious audiophile, they are an inexpensive, but most thoughtful gift. See the ad elsewhere in this issue for details on how to order. I 46514. 219/294-5571 Reader Service Card 20 AUDIO DECEMBER, 1975 New from Acoustic Research Introducing A new family of loudspeakers from Acoustic Research AR-MST/1 The AR Miniature Studio Transducer offers at moderate cost the flat energy response of AR's other new speaker systems, together with the high power-handling capability required in many professional applications. Along with the AR-MST/1's small size, light The AR -11 is designed for weight, and shallow depth, these optimum performance when characteristics make the placed against a wall, as in the speaker especially appropriate conventional bookshelf position, for the monitoring of Further, the designed -in remote-location recordings as or slightly away from two adjoining room surfaces. well as the accurate performance of the AR -1017 is reproduction of music in the preserved, whether the speaker is positioned against a wall, in a Both the AR -1017 and the AR -11 home, even at relatively high sound levels. corner, or even in the middle of a use a 12 inch acoustic room. Setting a single switch, suspension woofer, a 11/2 inch called the 'Woofer dome midrange, and a newly Environmental Control', will designed 3/4 inch dome ensure the correct level of bass highrange. energy for any of these positions. It is not possible to do this accurately with conventional Please send me a complete loudspeaker designs or description of the AR -1017, equalization techniques. AR -11, and AR-MST/1 speaker systems. AR -10n The AR -10n is the most accurate musical reproducer that Acoustic Research has ever made. It shares the characteristics of AR's previous speaker systems, smoothness of response, uniform dispersion, and low distortion. A significant additional feature of the AR -1017 is its ability to deliver uniform flat energy response in most listening rooms. AR -11 The performance drivers, and crossover of the AR -11 are identical to those of the AR -10n, except that the AR -11 does not incorporate a Woofer Environmental Control and the associated crossover components. Guarantee The workmanship and performance of all AR speaker systems are guaranteed for five years. A complete description of the new family of AR speakers is available free. Mail us the coupon today. Acoustic Research 10 American Drive Norwood Massachusetts 02062 Telephone 617 769 4200 A TELEDYNE COMPANY Please send me the AR demonstration record 'The Sound of Musical Instruments' (check for $5 enclosed) Name Address AU1 2 www.americanradiohistory.com AmericanRadioHistory.Com Audio ETC J Edward Tatnall Canby glance, it might have been no more than a technical AT FIRST shift in merchandizing, that casual announcement a few months ago from EMI, Electrical & Musical Industries of England. Far from it! Profound implications for quad- raphonic. A major record company on the move. And look! There's light at the end of the tunnel. Interesting that it should come from EMI, the sobersided giant of British conservatism, the same outfit that took a leisurely five years or so to make up its mind about the LP record after 1948. Inertia! Big companies have it. They can afford it. But also-momentum, once they get going. Being conservative in England, after all, generally means being absolutely unflappable. That's EMI. EMI's momentum can shake the record world. The new EMI decision: no more quadraphonic records. Don't jump. -That is, no separate quadraphonic records sold parallel to stereo in a dual inventory. Instead, once again we have a single basic EMI classical disc, and history is timelessly reversed, back to where we were before we had ever heard of four channels. And as things were before we had stereo. And as they were before the LP. Each of these technical innovations brought with it, for awhile, an uncomfortable dual inventory, two types of disc and a sort of workable compatibility, more or less. But within years, in each case, the industry returned to the traditional single release-just as soon as conditions permitted. So it is happening again. How very much in the old tradition, then, is EMI's present move! Positively classical. Here's how it works. EMI's classical discs (the pop field is left open) will no longer carry any special quadraphonic label or number or price. However, almost evidently all classical releases-across the board, the whole production-will bear a new standard designation, "stereo/quadraphonic." Every one of those records will be encoded for SQ quadraphonic and there will be no stereo equivalent at all. Does that, in a casual British way, go far beyond Columbia itself, the SQ mother hen! Rather. Quite breathtaking. Depending on circumstance, some EMI releases will be marked "stereo." No encoding. Solo instruments and the like, where it is felt to be unnecessary. No implications of better or worse, just a matter of aesthetic judgment. All the EMI classicals are in there together now, whether they happen to be stereo or quadraphonic. Single inventory. That is the key phrase. The quadraphonic aspect, you see, is both played up and played down. On the one hand it is now taken for granted, as though there were no further argument, and is routinely applied to the entire production-that plays it up, all right. On the other hand, quadraphonic is pointedly integrated into the larger aspects of record production, just another useful tool among many that bring us good music and hi fi on discs. That correctly plays it down. So infinitely reasonable! I'll bet the mother hen is in a flap, over here. We've had no such clear thinking (and action) from anybody on this side of the water, either from SQ or CD -4. In fact, for all our quadraphonic trumpetings hereabouts, we are still floundering all over the place, or sitting on uncomfortable fences with sharp points that keep getting sharp- er. An agony of noisy indecision and dangerous for all concerned. Imperturbable EMI! Cooler heads over there. EMI has stepped right in where, er, Angel fears to tread. Not to mention Columbia and RCA. Curious, for instance that, though the EMI story appeared in the trade papers, CBS itself flashed out the news in an "SQ Newsletter" to dealers and hi-fi writers. Curious that in that letter there wasn't a word about CBS's own thoughts and intentions-and would we all like to know them. Curiouser still that the word "Columbia" did not appear. The Newsletter came from the CBS Records Division. From which segment of CBS, in all its complexity, did we actually receive this interesting communication? And where was Columbia Records, the old mother hen herself? Odd. Could we read a veiled mini -hint here of some internal distress within the CBS empire? Could be. Because, as you know, from the very beginning of SQ the Columbia policy has been precisely the opposite of that now promulgated from EMI. A dual inventory, separate stereo and quadraphonic releases, side by side at a dollar's difference, the SQ product conspicuously promoted as deluxe, even to those gaudy gold labels. Could it even be, I thought to myself, that the big British SQ tail was beginning to wag at least a part of the U.S. (Columbia) dog? (Here now, enough of those mixed metaphors, What would Nipper think? An interesting thought. EMI is plenty big enough. EMI is by far the largest of Columbia's SQ licensees and worth a hundred of the others. Something must be going on there back behind the scenes. Canby. -Editor.) Hmmmm. AUDIO 22 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 Discover The Fourth Component! You have a receiver. You have a turntable. You have your speakers. You think you have it made. Well, think again. Think about the cartridge, because your pick-up pan make or break the performance of your audio system. It's the part too many stereo beginners forget. That important fourth part where the music begins. You may not realize it, but your cartridge and its stylus has first contact with the music in the grooves of your records. But it doesn't just plod along round and round producing all that sound. It's actually vibrating along the sides of the grooves in an incredibly complex dance that represents all the music on the record. And all too quickly for your eye to see, but not for your ear to hear. Because if your cartridge is faulty, no amount of expensive equipment ... speakers, turntable or receiver ... will make up for the distortion it can produce. That's why you need a cartridge you can depend on. One that's the best your money can buy. Specifically, a Pickering: Because a Pickering cartridge has the superior ability to "move in the groove" ... from side to side and up and down without shattering the sound of your music ... on your records. Because a Pickering cartridge possesses low frequency tracking ability and high frequency tracing ability (which TM\. It picks up the highest highs Pickering calls and the lowest lows of musical tones to reveal the distinctive quality of each instrument. Because only a Pickering cartridge can be individually and easily suited to your music system. Each is rated with a Dynamic Coupling Factor which tells the dealer immediately what kind of turntable or separate arm the pick-up needs whether your system is stereo or discrete quad. Your stereo cartridge. It's the fourth part of your music system that's too important to forget. And so is a Pickering. For further information see reader service card or write to Pickering & Co., Inc. Dept A, 101 Sunnyside Blvd. Plainview, N. Y. 11803 Check No. 33 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com se PICKERING "'for those who can hear the difference" With that SQ Newsletter there was enclosed a Columbia ad offprint showing a model who is buying up dual -inventory SQ discs, conspicuously marked quadraphonic. Was this sent along just to contradict EMI? I wouldn't know. Compatibility In all the quadraphonic camps since the beginning of four-channel disc the loudest tune has been COMPATIBILITY. Every quadraphonic disc always plays on any sort of equipment. True, true. But oversimplified. Trouble is, the sales people have found themselves somewhat limited as to what they can say on this subject. Limited to superlatives. The fact is that total compatibility is a very rare bird, unless, let's say, you mean one stereo cally enough, the separate stereo record which, at least in theory, sounds better as stereo than the quadraphonic disc, even though both will produce stereo on stereo equipment-compatability. That's the argument. And it can get to seem very important to the engineers and producers involved. Yet, as EMI understands, time is on the side of the quadraphonic engineer. If quadraphony remains viable, then the emphasis is bound to shift. A stereo disc with quadraphonic encoding becomes, slowly but surely, a quadraphonic disc that will play as stereo. Stereo mixdown becomes the secondary factor, as mono once did when stereo took over. Moreover, "compromise" recording techniques, for both types at once, most certainly Single inventory is the way out. It can be applied to any compatible system. disc and its twin, hot from the press. "Compatible," as everyone knows who plays discs and tapes, means a technical marriage de convenance, a convenient marriage (with divorce more or less taken for granted)-we can get along together as long as we have to. A working arrangement, for the time being, and don't tell me otherwise. So we have assorted compatible quadraphonic discs, but there's nothing permanent about the relationship. Indeed, compatibility has an important silver lining-it is dynamic, it changes as the scene changes. The emphasis is shiftable, right across from one side to the other as necessity requires. That applies to stereo/quadraphonic compatibility. It is true, then, that EMI's new combined stereo and quadraphonic disc involves a give and take, call it a compromise, between the ideal stereo sound and the ideal quadraphonic. They aren't the same, and it is here that Columbia, I think, gets very hot under the collar at the thought of a single inventory. Columbia has developed an experienced and dedicated SQ team over the years; it keeps its quadraphonic operations remarkably apart from stereo, right down the line from master tapes through separate mixdown and pressing (and often in the recording, where it all begins). This is a valid idea and can be applied to any quadraphonic production, as opposed to stereo. So we have, logi- will develop-EMI has already satisfied itself on this score. So the quadraphonic boys will come back into their own. Seems to me, this is a worthwhile compromise to make, if it will keep the quadraphonic art alive. "If" is the word! Can the four -channel disc, any type, survive at all as things now stand? I am beginning to doubt it. So does EMI. We have worked ourselves into such an unyielding impasse over quadraphonic that the corporate batteries are running dangerously low. If the big fellows pull out, we are in deathly trouble. There is an explosively exact limit to big -corporation patience in such impasses, as we know all too well. The major record producers are but the slaves of bigger entities whose bosses are not interested in aesthetics that do not pay. The danger limit has now been reached. It is an emergency. No question about it. Something has to be done very soon, or else. EMI has done it already. The proposition is, can we swallow a mild loss of technical flexibility, can we endure a major upheaval in production and distribution, in order to avoid a tragically greater loss-the whole shebang? It has come to that. Not for SQ alone but for all quadraphonic disc production-the whole bit. The EMI single inventory is the way out. It can be applied to any system, to all present systems that are "compatible." It could rescue all of them from collective extinction. It seems to be that the question of single versus dual inventory is now far more vital than the whole time honored argument as to which system is best. All systems are threatened! This we have got to understand. So if quadraphonic's time has come, it must either die or cease being a hepped-up special -order extra at extra cost. At all costs, in order to live, it must somehow blend itself into the great existing body of the art of recording, just as every other technical innovation in records always has. There, it seems to me, is the EMI message. Back to normalcy. And so we are shaken. One of the Big Companies has moved. If the other world record companies (including our own) will now please get right on this bandwagon, in whatever fashion they may choose (and via their own chosen euphemisms and slogans), if all will universally adopt the basic idea of one classical inventory and no duplication-then, I think, we will have reason to hope that quadraphony on disc will survive and grow. Without disc, you understand, there will be no quadraphonic. know-the pop field is bigger. But pop is also more flexible, as well as more demanding, and requires more leeway. If the classical disc is firmly established in the single inventory pattern, one disc per release, whatever type it may be, then pop music and all the rest will find an easy relationship within the same framework. After all, EMI isn't exactly an all -classic company. EMI recorded the Beatles, don't you remember. They still own a few little properties of that sort. They have pop plans too. But first-get classical on the rails. Done. The beauty of the single classical release is that it takes you off the hook, gives you flexibility. Cheaper, and so much easier to merchandize! Once again you sell records, period. You promote the most important thing you have to sell, the artistic product. Throw in as much or as little quadraphonic as you want, or none at all, without shaking any foundations. And are your dealers happy! Not to mention the customers. The whole systems is fluid again, things move, sales tracks are re -greased, there's confidence (no more of that painful confusion of choice), the aisles are clear (more room), the cash registers noisier. So much simpler, the whole deal. And the pay-off: merely a workable compromise in the sound, and not a bad one at all. I'm for it. I AUDIO 24 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 Our warranty records show that on average only one Revox buyer in six has never had a tape recorder before. The remaining five have all owned one or more makes previously. Since our warranty application invites comment. we are frequently told how happy our customers are with their Revox, especially when they compare it with their previous purchases. But too often we hear the lament: 44 IWISHI'D BOUGHT IT SAoNER ee o co co The incomparable Revox A77 priced from $899 Save yourself the cost of experimentation in tape recording. Select a recorder that will neither add nor detract from the original. Choose the A77 - and if your finances don't quite run to a new machine, try to find one second hand - in standard condition it will out perform other makes of new equipment at the same price. REWOX Buy it first - it's built to last Revox Corporation 155 Michael Drive Syosset N.Y. 11791 U.S.A. Revox International Regendorf 8105 ZH Althardstrasse Switzerland 146 a pv9 e 'ar Revox C. E. Hammond Co Lamb House see Ltd. a Church Street Chiswick London W4 2PB England ,ree 4.00eaye .9\ www.americanradiohistory.com AmericanRadioHistory.Com o ' ae o G o aJSe MAGNEPLANAR® loudspeakers are . . Dear Editor: extremely realistic sounding -and they've only 1" thick. Hear the Magnepan MG -11, exclusively at the following Magne pan dealers: EAST Audio Breakthroughs/Manhasset, NY Audio Etc. /Gainesville, FL .I Brookshire Music Machine/Anderson, SC Bryn Mawr Stereo/Bryn Mawr, PA Creative Audio/Colonie, NY DKL Laboratories/Silver Spring, MD D.S. Audio/Wyomissing, PA Electronic Workshop/New York Hi -Fidelity Center/Charleston & Huntington. WV Paul Heath Audio/Rochester, NY House of Sound & Sight/W. Palm [email protected], FL Fred Locke Stereo/CT & Springfield, MA Lyric Hi-Fi/New York & White Plains, NY Music & Sound Ltd. /Willow Grove, PA Music Center Hi-Fi/Charlottesville, VA Music Systems, Inc. /Charlotte. NC Myer Emco/Falls Church, VA & Wash. D.C. Myriad Sound/Garrison, MD Sight & Sound Ltd. /Bel Air, MD Sound Components/Coral Gables, FL Sound Experience/Huntington & Stony Brook, NY The Sound Shop/Norfolk, VA Sound & Sight/Boca Raton. FL Sound Room/Plattsburgh, NY Stereo Emporium/Buffalo, NY Stereo World/Ft. Myers, FL Taylor House/Iron Station, NC Vickers Audio/Chapel Hill, NC CENTRAL = Absolute Sound/Detroit. MI Audio Concepts/Houston, TX Audio Electronics/Prairie Village, KS Audio Labs/Des Moines, IA Audio Systems & Design/Omaha & Lincoln, NB Audio Specialities/Baton Rouge. LA Carlin Audio/Dayton, OH Equinox Systems/Grandville, MI Gill Custom House/Palos Hills, IL The Gramophone Ltd. /Norman, OK Hi-Fi Audio/Cincinnati, OH Hi-Fi Buys/E. Lansing & Ann Arbor, MI Hi-Fi Gallery/Indianapolis & Evansville, IN Hillcrest High Fidelity/Dallas, TX Hoffman's House of Stereo/Brookpark & Wickliffe. OH I/O Systems/Chicago, IL Jensen's Stereo/Burnsville, MN Opus Il/Memphis, TN Sound Environment/Mpls., MN Sound Shoppe/Green Bay, WI Stereo Shop/Cedar Rapids, IA Stereo Studio/Terre Haute, IN Swallen's Audio /Columbus, OH Victor's Stereo/Chicago, IL J. Westpfahl Audio Consult. /Rockton, IL WEST Audio Arts/Livermore, CA Boulder Sound Gallery/Boulder, CO Coffee. Tea or Stereo/Salem. OR Definitive Audio/Seattle, WA Garland Audio/San Jose. CA Hawthorne Stereo/Beaverton & Portland, OR Hi-Fi Matic/Culver City, CA Interior Systems/Las Vegas, NV Listen-Up/Denver. CO Magnolia Hi-Fi/Seattle, WA Jonas Miller Stereo/Beverly Hills, CA Music & Sound of Calif. /Woodland Hills, CA Quad Corner/Bellingham. WA Sound Company/San Diego, CA Stereo Hi-Fi Center/Gardena & Torrance, CA Stereo Showcase/Vallejo & Sacramento, CA Stereo Workshop/Berkeley, CA Tin Ear/Richland, WA Toad Hall/Corvallis & Eugene. OR CANADA Bay Blood Radio/ Toronto Ottawa Studio Sound/Ottawa The Sound Box/Vancouver Contact us if there is no dealer in your area. M A G N EPAN m ilI MAGNEPLANAR®PRODUCTS P O BOX 8602. WHITE BEAR LAKE. MINNESOTA 55110 Dealer inquiries welcome. Check No. 22 on Reader Service Card One + One i Four biamplification capability. Both the Dear Sir: We favor the technique described in the article on bi -amplification by Lovda and Muchow in the September issue of Audio. We recently designed a 1 -kilowatt system for a stadium using bi -amplification and Shure SR105 amplifiers with two low -frequency and six high -frequency horns. By connecting our speakers individually to the amplifiers, we missed the advantages of the "bridged -pair series connection" scheme that the authors 16 -ohm, high -frequency section and the 16 -ohm, low-frequency section of each system are made available for external connection. The Shure SR105 amplifiers used in this example, if operated at the mentioned maximum output -voltage capability of 28 volts rms, will deliver approximately 200 watts continuous to a 4 -ohm load or 100 watts to an 8-ohm load. In addition, two SR105 amplifiers may be "bridged" to provide approximately 57 V rms output resulting in a total power of 400 watts to an 8-ohm load. The question, then, is what circuit configuration of amplifiers and speakers will most efficiently drive the speakers for highest SPL operation? Analysis reveals that the optimum combination consists of four SR105 amplifiers split into two bridged pairs, with each pair driving two parallel - = mention will double the power output of each amplifier. With this technique, we could have halved the number of amplifiers and saved our client substantial cost. We congratulate the authors' honesty in bringing this cost- and energy saving technique to the public's attention. Unfortunately, the a.c. input power is rated at more than twice the audio output, so this method cannot be used to generate electricity. However, by a slight increase in efficiency, an important solution to the energy crisis would result. Jon R. Sank Cross Country Engineering Haddonfield, N.J. The authors reply We believe that Mr. Sank is referring to the comments in the "Summary" and, in particular, to Fig. 8A, the "Typical Biamplified Sound Reinforcement System for High SPL Operation." The intent of this portion of the article is to illustrate in general terms how to most efficiently utilize the components of a biamplified sound system. In the example described, the four 16 -ohm, wide -range loudspeaker systems are two-way systems with connected, low-frquency speakers. (Please note that due to a typographical error, the two low frequency speakers are shown series -connected instead of parallel -connected in Fig. 8A.) In this way, each pair of speakers constitutes an 8 -ohm load. A bridged amplifier pair will deliver 400 watts to this 8 -ohm load, while a single amplifier will deliver 100 watts to this 8 -ohm speaker combination. In the article, we elected not to explain in great detail the subject of amplifier bridging. Rather, it was included to inform readers that his technique was available with amplifiers offering this feature. We certainly hope that this explanation will clear up any confusion that may have resulted. John M. Lovda Stephen Muchow Senior Development Engineers Shure Bros., Inc. Evanston, Ill. AUDIO DECEMBER, 26 www.americanradiohistory.com AmericanRadioHistory.Com 1975 Any LUX amplifier or tuner that doesrt meet or exceed every rated specificationwont ever reach you. match or exceed every published specification It's one thing to produce components with an is given the appropriate remedy. When a unit passes, impressive list of published specifications. It's quite it is returned to its carton together with a copy of the another matter to ensure that every unit will meet Certificate for the information of its future owner. or exceed each of those specifications. But this is Another copy stays with us as a permanent record. precisely what LUX does with its entire line of power As for the specifications themselves, here are amplifiers, preamplifiers, integrated amplifiers and some examples. The Luxman M-4000 power amplifier and tuners. has less than 0.05% harmonic and intermodulation LUX components were conceived and designed distortion at any frequency from 20 to 20,000 Hz, for that very special breed of audiophile whose critical even with both channels driven simultaneously to its requirements for accurate music reproduction are met rated output of 180 watts per channel into 8 ohms. only byseparateamplifiersand tuners, And of those prodAnother M-4000 specification: signal-to-noise ratio ucts, the very best that the state of the art can provide. beyond 100 dB. Hence, the following procedure takes place at Another example is the C-1000 preamplifier. Its our facilities in Syosset, New York. phono -input circuits are virtually overload proof, Every unit received from the factory in Japan is accepting almost half a volt of audio signal at 1000 Hz. removed from its carton and placed on a test bench The distortion of its phono -preamplifier circuits is an where it is connected to an array of test equipment, astonishingly low 0.006%, and the rest of the which includes a Sound Technology 1700A Distortion preamplifier circuits add only 0.001% more. Measurement System and 1000A FM Alignment There's one more expression of our confidence Generator, McAdam 2000A Digital Audio Analyzer in our products. If any of them malfunctions during System, and Iwatsu Electric SS5100 and 5057Z the first three years, let us know. We'll not only fix it 5057Z Synchroscope. promptly, but will pay the freight both ways, as well as Every control, switch, meter and indicator supply a shipping carton if needed. undergoes an operational check-out. There nothing Some day, all manufacturers may adopt these unusual about this. Any reputable manufacturer can procedures. For LUX, it's the only way to go. From be expected to do the same. Or at least spot check the very beginning. a shipment. With all this, we think that neither our specifications But LUX has only begun. Every specification is nor our procedures for verifying them is nearly so then measured against its published rating.That means important as your satisfaction with 14 individual tests fora power the end result: the most accurate amplifier, 14 for a preamplifier, One of these Performance Verification and musical reproduction you can Certificates is included with every unit. 20 for an integrated amplifier and hear. 7 for a tuner. The end result can be best Each verified specification appreciated at a select number of is entered by hand on a ffMnoÑ dealers whom we guarantee to be Performance Verification as dedicated to fine music Certificate. Any unit that doesn't reproduction as we are. CfA1KGIIF Luxman M-4000 Power Amplifier -180 watts per channel minimum continous power, both channels driven simultaneously into 8 ohms. Total harmonic and intermodulation distortion less than 0.05%. Frequency response: 5-50,000 Hz, ±1 dB. Signal-to-noise ratio:108 dB. Features include: separate power supplies for each channel, including output and drive stages. Two-meter power -output display in combination with LED peak-output indicators reveal dynamic range of program material. Output level set by precision potentiometer with 1 -dB click stops. $1,495.00. Luxman C-1000 Preamplifier-Total harmonic and inter modulation distortion: 0.007% at 2.5 V, 20 Hz-20 kHz, all output signals. Frequency response: 2 Hz-80 kHz, +0, -0.5 dB. Signal-to-noise: >65 dB. Phono overload: 450 mV @ 1 kHz, 3.5 V @ 20 kHz. RIAA equalization: ±0.2 dB. Features include: tape -monitoring and dubbing for two decks, six selectable tone control turnover frequencies, linear equalizer, twin high and low noise filters, variable phono -input impedance, variable input sensitivities, "touch -mute" attenuator, speaker system selectors. $895.00. LUX Audio of America, Ltd 200 Aerial Way, Syosset, New York 11791 In Canada: AMX Sound Corp. Ltd., British Columbia; Gentronic Ltd., Quebec www.americanradiohistory.com AmericanRadioHistory.Com Mitring With The 3 -Point y:iem IN ORDER to understand the ad vantages of the three point pick-up system, it is necessary to be aware of the distinction between binaural and stereo. A good binaural recording makes a poor stereo recording and vice versa. The fact is that situations in which acceptable stereo recordings can be made with two microphones are severely limited in number. The seemingly simple case of a solo instrumental performer on stage serves to illustrate this point. A recording made with two cardioid (uni -directional) microphones, when EDITOR'S NOTE: The Nakamichi folks have recently released a small booklet on the three-point recording system, entitled "The Nakamichi Live Recording System,"several parts of which are reprinted here. This technique makes use of a third or blend mic in addition to the more usual stereo pair to produce a greater sense of depth or space in the recording. The system also allows a wider latitude in placing the basic mic pair 28 played back over monitoring loudspeakers, will in most cases approach one of two extremes depending on microphone placement: if the microphones were fairly close to the performer, the instrument will seem 10 feet wide; if they were placed farther away, there will be a left and a right but a hollow middle, creating the illusion that the performer is in two places at one time. A proper three point pick-up would produce a recording not only with correct left right perspective but with depth as well. The performer will be heard oc to achieve the correct stereo or left -right image. While the basic technique calls for the use of a recorder with a third or blend mic input, tape decks with only a pair of inputs can be adopted to the technique if a mixer with a blend feature is used. The Nakamichi booklet also gives many valuable tips on relative levels and placement of mics for various instruments. It is available through the firm's dealers. cupying the correct amount of space at the correct point on the stage. The effect becomes easier to understand when one realizes that the success of binaural reproduction is largely dependent on certain psycoacoustic phenomena. Stated simply, the human brain, when isolated from external factors as in binaural reproduction, is amazingly capable of filling in details. Stereo reproduction cannot take advantage of these psycoacoustic effects. It becomes necessary, therefore, to take special steps in the recording process to insure that the sound, when reproduced over monitor loudspeakers, will be an accurate rendition of the performance. Many amateur recordists will use multiple microphones (more than 3) in an attempt to produce a "professional" recording. While it must be acknowledged that certain situations call for multiple microphone techniques, it must also be pointed out that such situations are rare and that such techniques are quite difficult to master. Phase interference between microphones (resulting in peaks and cancellation of certain frequencies) AUDIO DECEMBER, 1975 With an Empire wide response cartridge. A lot of people have started "trackin"' with Empire cartridges for more or less the same reasons. More separation: "Separation, measured between right and a frequency of 1 left channels at for any carremarkable kHz, did indeed measure 35 dB (rather Guide, The Feldman Lab Report. Less distortion: `:.. the Empire 4000D/III produced the tridge)" FM sponse yet measured from a CD -4 cartridge-within ±2 flattest overall redB from 1,000 to 50,000 Stereo Review. More versatile: "Not only does the 4000D/III Hz'.' provide excellent sound in both stereo and quadriphonic reproduction, but we had no difficulty whatever getting satisfactory quad playback through any demodulator or with any turntable of appropriate quality at our disposal" High Fidelity. Less tracking force: "The Empire 4000D/III has a surprisingly low tracking force in the I mean 4 channel types, seem 1/4 gram to 11/4 gram region. This is surprising because other cartridges, and to hover around the 2 gram class" Modern Hi Fi & Stereo Guide. For the complete test reviews from these major audio magazines and a free catalogue, write: Mfd. U.S.A. Empire Scientific Corp., Garden City, N.Y. 11530. I I Choose the Cartridge Designed to Play Best in Your System Plays 2 Channel Stereo Plays 4 Channel Discrete (CD4) i r and Super Stereo Plays All 4 Channel Matrix Systems (SQ, QS, RM) 400D Frequency Response in Hz: Tracking Force in Grams. Stylus Tip: For use In 400D D/I 2000 200D 2000 2000 2000 E/I E/II E/III D/II 5-50,000 5-45,000 10-40,000 5-35.000 6-33,000 8-32,000 10-30,000 10-28,000 3.0 3.0 3.0 5 0 5 0 5.0 5.0 5.0 more than 35dB more than 35dB 35dB 35dB 35dB 35dB 30dB 30dB Output Voltage per Channel at 3.54 cm/sec groove velocity: Channel Separation 4400D DIM Model 1/4 to 11/4 1/2 to 11/2 ï4 to E 11/2 1/2 tO 1 1/2 t/2 tO 1 1/2 i4 to 1 t miniature nude miniature nude miniature nude nude nude nude diamond with diamond with diamond with elliptical elliptical elliptical .1 mil tracing .1 mil tracing .1 mil tracing diamond diamond diamond radius radius radius .2 x 7 mil .2 x .7 mil .2 x .7 mil V4 Dimensional M4 Dimensional 'M4 Dimensional turntable or turntable or turntable or turntable or turntable only turntable only changer changer changer changer 1 to 3 1 to 3 diamond spherical diamond .3 x .7 mil .7 mil elliptical changer only changer only (Red) (Smoke) i i i S S (White) (Yellow) (Black) (Clear) Check No. 12 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com (Blue) (Green) problem as the is increased. Many professional live multi -mike recordings, in fact, suffer from this phenomenon and end up bearing little resemblance to the actual performance. With practice and experimentation the recordist will soon discover that the three point pick-up system is ideal for the large majority of live recording situations. becomes more of a number of pick-ups Microphone Choice While perhaps it need not be said that a successful live recording invariably depends on the use of high quality microphones, a few general guidelines on the use of uni -directional (cardioid) versus omni-directional (non -directional) microphones in the three point system should be helpful to the amateur recordist. Cardioid is usually the choice for the two stereo microphones. In general, however, unless there is good reason to use cardioid microphones, omni-directional microphones are preferable as they will yield superior results. If wide separation is physically impossible, for example, directional microphones may be desirable to establish stereo left and right. Cardioid microphones will also help to suppress audience noise, very often a problem in live. recording. The blend microphone can be either uni -directional or omni-directional depending on the recording situation. An omni-directional microphone circumvents the proximity effect (boosting of lower frequencies) which one encounters when closemiking with a uni -directional unit. An omni-directional microphone also solves the problem of uneven sound caused by slight movements by an instrumental or vocal performer. It is occasionally necessary to suppress in- formation behind the microphone. In such cases a uni -directional device must be employed. Most high quality uni -directional microphones, fortunately, are equipped with a switch able low -frequency attenuating network to minimize proximity effect. There are a few select cases where proximity effect may actually be desirable. Here again, the uni -directional microphone is the solution (the attenuating network, if provided, should be bypassed, of course). If time permits, it is best to try both types and choose the one that yields the most natural sound. The advanced recordist will most probably want to experiment with more sophisticated microphones, as the super -directional (shotgun type) or the super-nondirectional (pinpoint pick-up type) microphone. Super -directional microphones are not only useful for picking up sounds from a distant source but also for stereo pickup in halls or churches with excessive and prolonged reverberation, which tends to make such recordings sound muddled and cavernous. Super-nondirectional microphones are highly refined omnidirectional microphones. The expert recordist will often use a pinpoint microphone in place of a standard omnidirectional unit, even though the former requires much more critical placement. The pinpoint microphone has the advantage of smoother high frequency response (almost no diffraction effects because of reduced pick-up element size) and truer omnidirectional response at higher frequencies. It is usually the case, unfortunately, that monitoring during a live recording session must be performed with headphones. This causes no difficulties for the binaural recordist, but the stereo recordist is confronted with the rather complex problem of creating a tape which will faithfully reproduce the performance over stereo loudspeakers while monitoring on -location with headphones. Clearly there is no substitute for experience in this matter. The seasoned recordist is able to extrapolate the binaural information and thereby position the microphones and set levels to produce a perfect stereo recording. It should be pointed out, nevertheless, that choice of headphones can have a profound effect on the end result. Certain headphones are not suited to the purpose of on -location stereo monitoring because of their physical and/or acoustical characteristics. Open-air type headphone provides no isolation from external sound making it relatively difficult to monitor live recordings unless the recordist situates himself in a rather soundproof room. Generally poor results in terms of balance can be expected when one monitors with headphones which have boosted low and high frequency responses (in other words a suppressed midrange). It is much more preferable to use headphones which have slightly attenuated responses at the lower and higher ends of the audio spectrum. Finding the optimum positions and setting the levels for proper balance among the microphones are the most important and the most difficult tasks in live recording. There are numerous factors to be taken into account. Type of instrument, type of ensemble, type of microphone, and acoustical characteristics of the room or hall (which are affected by factors such as size, shape, material, size of audience, etc.) are but a few of the details which must be considered in positioning the microphones. Once the microphones are optimally located, the levels must be set so as to achieve the most natural balance between the stereo and blend microphones. It would be impossible to postulate exact microphone locations and level settings for any given recording situation. If it were possible to do so, live recording would not be quite so enjoyable. There is regrettably little time, however, for one to experiment with microphone placement and level setting at an actual performance. The successful live recordist, therefore, relies heavily on experience gained from past recordings and on knowledge gained from those sessions in which there was ample time to experiment. The following examples of specific recording situations are intended as a guide. Combined with the availability and proper use of top -performing equipment and some time to experiment with the variables, these diagrams and suggestions should enable the serious amateur to produce highly successful live recordings. Piano Solo In recording a solo performance the blend microphone is used to pick up the primary sounds emanating from the instrument while the stereo microphones are used to pick up the piano's natural ambience and room reverberations. Blend mic: Place the microphone to pick up direct sounds from the piano as shown in the diagram. This microphone must be placed rather close in order to capture the percussive qualities which lend clarity to the piano. If the microphone is placed too close to the strings, however, single notes will stand out and the resulting recording will sound uneven. Correct placement can actually depend on the composition being performed! If the piece limits playing to the lower half of the keyboard, for example, the microphone should be placed farther away from the keyboard than usual. Stereo mics: Placement of these microphones depends largely on room acoustics. As a general rule of thumb, they should be at least 6 ft. high and 3 ft. apart. The axis formed by the two microphones, however, should always AUDIO 30 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 A cartricJge in a ¡year tree. Shure V-15 Type III stereo phono cartridge will earn you the eternal endearment of the discriminating audiophile who receives it. What RE8 BIREC makes the V-15 such a predictable Yuletime success, of course, is its ability BUYINi ND! to extract the real sound of pipers piping, drummers drumming, rings ringing, et cetera, et cetera. In test reports that express more superlatives than a Christmas dinner, the performance of the V-15 Type III has been described REED Its sound is as neutral and a virtually flat frequency response as 1g76 stereo that if you're the giver, which means All be desired." of can uncolored as pirecto ôQ `` you car make a hi-fi enthusiast deliriously happy. (If you'd like to receive it tt,e Buy"' Chase yourself, keep your fingers crossed!) /(3 arp id9 bée31. i15.. Shure Brothers Inc. e tep tow 222 Hartrey Ave., Evanston, IL 60204 FR I --H A gift of the i ... "... In Canada: A. C. * Simmonds & Sons Limited S U FREE! 1976 Stereo Directory & Buying Guide with the purchase of a Shure V-15 Type Ill, or the M95 series, M75 Type Il or M91 series of cartridges. Simply send us your warranty card wi:h the notation "Send Free Buying Guide" before Dec. 31, 1975. (Offer subject to supply and may be withdrawn at any time.) Check No. 43 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com be parallel to the strings (perpendicular to the keyboard). To give an example of how room acoustics affect placement, it can be stated that a large hall would call for the stereo mi- controlled quite well by adjusting the level of the blend mic with respect to from the soloists than the stereo mics. Exact placement will, of course, depend on the room or hall. Be careful not to place this mic too far from the stage as it must pick up the piano accompaniment. A toi crophones being positioned farther away and more toward the keyboard than they would be for a smaller hall or room. Levels: The blend microphone is the main source. The stereo microphones, therefore, should not be allowed to overpower the blend mic. Vocals with Piano Accompaniment the vocalist and the blend mic is once again the primary pick-up. Blend mic: Place the mic at a level just above the vocalist's head. Be careful not to place it too close. It is highly recommended that a windscreen be used to minimize pops and blasts. A dynamic microphone is generally preferable to a condenser type for vocal recording. Stereo mics: These must be positioned to pick up the piano accompaniment in addition to the reverberant sounds. Placement will once again largely depend on the room or hall The main source is acoustics. Levels: The balance between the vocals and the accompaniment can be the stereo mics. The level of the accompaniment should generally be between 45-50 percent of the vocal level. If the blend mic is too high, the recording will sound monaural and balance will suffer. If the stereo mics are too high, the result will be a muddy sound, lacking localization of the vocalist. Vocal Quartet With Piano Accompaniment In the examples given earlier the blend microphone performed the primary function of picking up the direct sounds from the solo instrument or vocalist. In the following example, the stereo microphones must take over this function since the main source, the vocal quartet, is spread out and requires increased coverage. Blend mic: This must not be set too close to the singers. Place the mic at least 2 ft. higher and 3 ft. farther away www.americanradiohistory.com AmericanRadioHistory.Com c A C Stereo mics: Use the guidelines given for the blend mic in the example of the vocal solo with piano accompa- niment. Levels: Since the stereo mics are the primary pick-ups, levels must be set so that the blend mic does not overpower the direct sounds from the vocalists. String Quartet Recording a string quartet calls for microphone placement quite different from that of the preceding example. There are several reasons for this. There is, firstly, no piano accompaniment; secondly, balance among the instruments is more likely to be a problem than in the case of the vocal quartet. There is, thirdly, the added AUDIO 32 r DECEMBER, 1975 It's all here! The power, the precision, the purity. One look at that heat sink w II convince you that no one puts your money where it counts, ike Dynaco, nto the gut: of the Stereo 4000. And whet cones o.:t is perection. Every wanted feature, p us these optional accessor es Ultra high power mono conversion cit. Meters tc watch the nusic. A fan to play it really cool. Rack monts to keep it it suspense Loaded wit!- protection circuits, so the power is only where you raant t, including the unique DynaguardTM a similar speaker saver. One reviewer said, "excellent device should be a par of any high power amplifier." Join the thousands who nave built this kit in 3 or 4 evenings, and save orer $2C0. To see f ow easy it really is, send $2.50 for detailed manual anc performance data. It's a small investment in Dynakits-:he leacer in the world of sound value. ... Write Dynaco, Box 88, Blackwood, N.J. 08012 for free literature. www.americanradiohistory.com AmericanRadioHistory.Com requirement of picking up instrumental ambience as well as the room or hall ambience. Blend mic: Start with this mic in a central position with respect to the four instruments. If a problem with balance exists, the mic should be placed toward the weaker instrument. The mic should be placed high enough to clear the heads of the play- Jazz Trio Church Choir with Organ Many of the basic principles underlying the previous example apply to this case as well. Blend mic: This mic should initially be set in a central position (usually near the drums) and then repositioned, if necessary, to achieve proper balance. It should be placed high enough to clear the cymbals of the drum set. Stereo mics: The spacing and distance from the ensemble of these mics will of course depend on room acoustics, but the spacing between the instruments will also be a factor. If I 94; Because of the highly reverberant acoustical nature of most churches, critical microphone placement becomes particularly difficult. Blend mic: Use this mic to pick up direct sounds from the organ. Distance from the pipes, height, and lateral position will depend on the characteristics of the church and the organ. Under most circumstances, an omni-directional microphone would be preferable. Stereo mics: Place these mics in front of and above the choir. Experiment carefully with placement to achieve a full, rich sound with the right amount of reverberance. The mics must be close enough to capture the diction and far enough to avoid highlighting individual singers. Levels: Balance between the organ and the choir can be easily achieved by the proper setting of levels. ers. If the mic is placed too low, the music stands will interfere with pick- up of direct sounds from the instruments. Stereo mics: Place these microphones according to the room or hall acoustics. They will generally be placed higher than the blend mic and at least 3 ft. from the frontmost players. Levels: Although the blend mic is picking up the direct sounds from the instruments, care must be taken to avoid setting this mic too high in level as the resulting sound will be overly monophonic. Start with roughly equal levels for both the blend and stereo mics. Church Organ Solo the piano and bass, for example, are set very far apart, the stereo mics will have to be separated a little wider, placed a bit lower and closer to the ensemble than if the group were compact. Care should be taken, though, to avoid placing them so close that the recording loses "liveness" or the sense that the trio is performing in a room or hall. Levels: Follow the guidelines given in the previous example. Most church altars are constructed in such a way that they make ideal pick-up points for reverberant sound. Blend mic: Place this mic facing the altar. Experiment with height and distance to obtain a broad reverberant sound free from harshness caused by local resonances. Stereo mics: Position these mics to pick up direct sounds from the organ pipes. They must be close enough to capture all the overtones which give AUDIO DECEMBER, 34 www.americanradiohistory.com AmericanRadioHistory.Com 1975 and you'll drop all the others. new cassette on the market. The FUJI IFX, that soon will be the standard of excellence for top quality, truly high fidelity reproduction. It already is in many parts of the world. FUJI EX gives you the music you want, the way you want your music. Clear, crisp sound over the entire audio frequency range without perceptible distortion. A signal. to -noise ratio of better than 58 db. No hiss. Virtually failure-proof. The finest music at your fingertips without the need for any special bias. Drop in at your FUJI dealer today; then drop in a FUJI and hear music as you have never heard it before. FUJI FX cassettes come in lengths of 46, 60 and 90. Also available, a full line of FUJI FL Low Noise cassettes in lengths of 30, 60, 90 and 120 minutes. FUJI Photo Film U.S.A., Inc. The Empire State Building, New York, New York 10001. There is a a Pure Ferrix cassette FUJI FILM Pure-Ferrix Excellent Music Performance .y7K WE:11 <MED> T14E TAPE THAT'S HEARD Check No. 15 on Realer Service Card www.americanradiohistory.com AmericanRadioHistory.Com AROUPO 77E WORLD Levels: Relative levels will vary greatly according to the acoustical properties of the church and organ. Keep in mind that the stereo mics are the primary pick-ups. the various stops their particular sound qualities. Outdoor Recording I ` ....... I 1 ....................... institute of audio research offers an ongoing program in multitrack - music recording New classes for the winter quarter begin January 6, February 2, 1976 recording technology PDR-1 02 - Practical Disc Recording 33 hrs. The synthesizer as an instrument and "special effects" device. Includes lab. - 39 hrs. Hands-on study of tape to disc transfer. SIP -Studio Technology and Practice - 60 hrs. The nucleus of our multitrack recording curriculum. CR-110-Control Room Lab- 30 hrs. Students utilize professional equipment performing operation and test procedures. RSW-300 Recording Studio Workshop 30 hrs. Ten 3 -hour sessions operating a 16 track studio. -ill seminars Digital Logical Design Seminar - 3 Days. Elements of digital circuit design. Meaningful applications. Producers's/Arranger's Workshop - 3 Days. Institute of Audio Research laboratory facilities develop techniques of multitrack recording. Audio Systems Design - 4 Days. Theory and methods for interface design of audio systems. Design sessions aided by programmable calculators reinforce class discussions. - audio-music FAT-100-Fundamentals of Audio Technology 1 30 hrs. Study of fundamental audio concepts. Fundamentals of AudiaTechnology 2 FAT -200 - 36 hrs. Operation and theory of audio amplifiers, filters, feedback systems, etc - SST -200 - - Synthesizer Studio Techniques institute of audio research 64 University Place New York, N.Y. 10003 212 677-7580 - Windscreens are a must for outdoor recording. In some cases the standard windscreen supplied with the microphone may be inadequate. If so, take the thick part of a nylon stocking and wrap it tightly around the standard windscreen. Moving sound sources: Place the left, blend, and right microphones in line along the axis of motion. Spacing of the mics will depend on the speed of the source. The faster the source, the farther apart the microphones should be. When recording a fast moving steam locomotive, for example, if the mics are placed too close together, there will be very little stereo effect. Static sound sources: Place the three microphones in a horizontal plane fairly close to each other at 90 degree angles to each other. When recording sounds, such as bird or insect noises, which tend to come from all directions, three cardioid microphones placed in this manner will yield a very natural stereo effect. Levels: In each case above, set levto obtain the most realistic balance and separation. els Check Pla. 20 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com 36 AUDIO DECEMBER, 1975 THE NEW ACTION -LOOK AT ASTATIC Means New Profits For You OVER 100 ITEMS IN THE NEW ASTATIC AUDIO ACCESSORY LINE NEW MICROPHONE ACCESSORIES STEREO HEADPHONES AUDIO CABLES, PLUGS AND ADAPTORS RECORD ACCESSORIES 45 RPM SPINDLE ADAPTORS THE ASTATIC CORPORATION Conneaut, Ohio 44030 U.S.A. In Canada: Canadian Astatic Ltd., Scarborough, Ontario M1H 2V5 Export Sales: Morhan Exporting Corp. 270 Newtown Road, Plainview, New York 11803, U.S.A. THE NATION'S ONLY MANUFACTURER OF ALL 4: MICROPHONES, PHONO CARTRIDGES, NEEDLES AND TONE ARMS Check No.1 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com Language of High Fidelity Part XIII Martin Clifford E VERY ELECTRONIC SIGNAL from whatever source ultimately appears at the signal input of the main or power amplifier. The FM signal has shucked off the cocoon supplied by the radio -frequency carrier wave; the phono signal becomes the electronic equivalent of the twists and gyrations of the stylus in the record grooves; the tape signal has emerged from the magnetic whirls that produced it. Thus, at the input to the main amplifier, all of these signals resemble each other closely, and you can select any one of them for processing by the main amp. Up to this point, we have been interested only in the voltage amplitude of the signal, and we've talked in terms of signal voltage, not signal current or power. It is true that the A.C. POWER A.C. SIGNAL VOLTAGE e. PRE AMP A.C. SIGNAL VOLTAGE D.C. POWER MAIN AMP E( A.C. POWER 4. D.C. POWER POWER SUPPLY FROM A.C. POWER LINE 1-The power delivered to the speakers by the power amplifier comes from the power supply, but is controlled by the signal voltage. Fig. main amp will provide some further voltage amplification, but that is incidental to its main job. What we need is electrical power for our speakers. In this sense, we may regard the amp as an appliance-a device for turning electrical power into some other kind of energy-just as a toaster, broiler, or a steam iron is an appliance which converts electrical energy into heat. Although the terms "power amp" and "main amp" are often used interchangeably, "power amp" unfortunately suggests that it somehow manages to amplify power; this is wrong. This amplifier takes electrical energy out of the household electrical outlet and delivers it to one's loudspeakers. However, it doesn't do this directly-changes must first be made in the frequency and amplitude of the electrical power. These changes will be dictated by the audio signal input to the main amp. Whence the Power While the signal at the input to the power amp is a complex a.c. waveform, it is just a voltage and can exist at the amp's input without any sound coming out of the speakers. This is comparable to the case in your home in which an a.c. voltage is present at every power outlet along the baseboard, yet whether power is used or not is your decision. The moment you decide to use it (by plugging in an appliance), we are no longer dealing just with voltage (which is pressure), but with voltage and current (electrons flowing). Taken together, these two constitute power. The power amp does not generate power-it is simply a device for controlling the power made available to it by its power supply (usually on the same chassis). (See Fig. 1.) And that power supply gets its power from your a.c. power line outlet. This may seem like a Rube Goldberg way of doing things, but it's the only way we have. The ideal method AUDIO 38 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 STEREO PHONO CARTRIDGE suddenly there is the definition you have never been able to get before! AH! DEFINITION-That elusive quality of clearness and accuracy never quite attainable before. (If you can't extract it at the point of contact with the record, the rest of your equipment won't deliver it to you.) The design philosophy of the SONUS cartridge is to use the latest refinements in material and techniques to convert the motion of the record groove into a precise electrical replica, thus assuring the highest possible sonic accuracy and definition. The electromagnetic structure of the cartridge is exceptionally efficient and has been arranged in such a way that the point of transduction is placed as close as possible to the record surface. This enables the distance from the stylus tip to the energized armature to be kept extremely short, thereby minimizing the chances of the motion being significantly changed, and/or extraneous resonances introduced. It further enables the moving element to be kept exceedingly light and rigid. Indeed, we believe the total moving structure to be lighter than that of any other magnetic cartridge of which we are aware. Great care has been taken with the cartridge geometry, not only to minimize vertical tracking error but also to ensure accurate transmission of the stylus motion to the generating armature. This has been achieved by (among other things) positioning the stylus tip on the same axis as the armature so that none of the stylus motion is lost in rotation or affected by any possible rotational resonances. The stylus pivot is located at the dynamic center of rotation of the moving system and is fabricated from material having optimum elastomeric properties, providing an extremely linear and highly compliant suspension. In sum, we have a transducer system characterized by reproduction of exceptional accuracy, clarity and definition, and capable of perfect tracking and tracing at very low stylus forces. Write to SONUS customer service for full line catalog and the name of the franchised dealer nearest you. Your franchised dealer will be happy to demonstrate the superior qualities of this cartridge. Check No. 46 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com SONIC RESEARCH INC. 27 Sugar Hollow Rd., Danbury, Ct. 06810 Represented in Canada by: PACO Ltd. 45 Stinson St. Montreal, Quebec would be to eliminate the amplifier by connecting the signal voltage to the a.c. power line, and connect the result to the speakers. Instead we must take from the a.c. line the a.c. power, which consists of a sine wave voltage and a sine wave current, and convert it to d.c. This is the function of the amplifier's power supply. The power amp, then, is a component which receives d.c. power from its power supply section and reconverts it to a.c., which varies in frequency and amplitude according to the input signal (program material). The power line supplies current which is a sine wave, usually 60 Hz in frequency. The audio power coming out of the amplifier varies from about 30 to 20,000 Hz (depending on the amp design), and its amplitude is continuously changing. This current, flowing through the voice coil of the speaker, accomplishes work. It's forced into the voice coil by voltage. Together the two may be measured to compute the amount of power the speaker uses. Function of the Audio Signal One way to describe the relationship between the audio input signal voltage and the amplifier is to say that the amp is a faucet and the input signal voltage is the valve in that faucet. While the amplifier directs the current to its appointed location, the input signal controls how much of that signal will reach the locations. The current flowing through the speaker voice coil should also have the same waveshape as the controlling signal. If it's exactly the same (it can never be a perfect copy-that would mean zero distortion!), the amp has done its job perfectly. If it changes very little, it's done a good job. If the output power has things in it that weren't in the input signal, or if it changes their relative amplitude, we have distortion. Power Amp and Power Supply Since the power amp gets its power from the power supply, it should be obvious that it cannot deliver more power than it receives from the house current a.c. line. The function of the power supply is quite simple-to rectify the power line a.c. current and deliver d.c. to the power amp. It may help if you consider the power supply as a d.c. power reservoir. The power supply consists of three important parts: a transformer, a rectifier, and the filters. The transformer changes the house current at 115 volts to whatever the amp requires (in tube days it was 300 to 500 volts; generally today it's between 30 and 80 volts). In addition the transformer isolates the amplifier from the power line. If it did not, we'd have the good possibility of lethal shock, which is present in most small TV sets and many other appliances connected directly to the power line (they all have insulated cabinets to protect the user). The rectifier converts the a.c. into pulsating d.c. And the filters, consisting mostly of large capacitors, PEAK RMS AVERAGE 100% 70.7 63.7 Fig. 2-Peak, rms, and average amplitude points on wave of voltage or current. a sine smoothes the pulsating d.c. supplied by the rectifier into nearly perfectly smooth d.c. In the days of tube equipment, power -supply capacitors ranged up to 500 microfarads (NF). But today, with much lower working voltages, the size of range and up. many capacitors is in the 10,000 if Describing Power Measuring d.c. power is easy. Nor is it all that difficult to measure sinewave a.c. power. But it becomes troublesome when we are talking about complex wave signal currents and signal voltages-that is, signal power. For d.c., we just multiply voltage and current to get power in watts. For example, two amperes of current at 30 volts equals 60 watts power. Simple. For sine wave a.c. (if the voltage and current are in phase), the same simple multiplication process is used: Voltage (E) times current (I) equals watts power (W). The formula is written IxE= W. However, because we use a.c. power in many ways, we make several different measurements of a.c. waves, as may be seen in Fig. 2. There are three main points at which a sine wave is usually measured. One is at the top, called the peak (though it could as well be the bottom). Another is the rms value, which is equal to 70.7% of the peak value. This is also called the effective value. Finally we come to the average, which is equal to 60.3% of the peak value. Note that the sine wave values we're discussing here may be either voltage or current but not power. Remember that except for test purposes, the wave shapes a speaker receives are very rarely simple sine waves. Instead they're complex shapes produced by voices and instruments. Further, the speaker doesn't use just need voltage, or just current, but both, which is power. Now, while many measuring instruments are calibrated in rms units (voltmeters and ammeters), a wattmeter measures average watts. That's because the product of rms volts and rms amperes (voltage and current) is not rms watts, as you might imagine, but average watts. Thus, when you read a spec sheet saying so many watts rms, think average watts instead. While rms watts is thus a misnomer, you might also hear rms power sometimes also called continuous power because this is the amount of power the amp can handle for an indefinite period of time without interruption. Power amps are able to deliver more than their average (so-called rms) power for short periods of time, depending on the demands of the program material. If there is a pianissimo passage followed by a sudden clash of cymbals, the demand for additional power is comparable to momentarily turning on the air conditioner in your room-either the power company delivers or you will remain just as warm as you were. Ditto with the power amp. It will deliver more than the average power, but how much more depends on the size of the filter capacitor reservoir and the current passing ability of the rectifiers (and the transformer) in the power supply. This emergency power is variously called maximum power, dynamic output, or music power. Music power is the maximum power available for a very short period from the main amp and used to be seen fairly widely on spec sheets and in catalogs until late 1974 when the Federal Trade Commission (FTC) power -rating rule went into effect. Music power described the amp's ability to handle brief power peaks as compared to sustained power levels. Thus, an amplifier capable of delivering 50 watts of power continuously might also be capable of delivering 80 watts for a short period of time. It was this 80 watts which would have been the amp's music power rating. With the FTC amplifier power-rating rule in effect now, only one kind of power rating, continuous, will be used for good high fidelity equipment. All other ratings are now obsolete. AUDIO 40 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 MOM We're not afraid to turn our back on you. ® SYLVANIA .n"K." .".."... Q) , PTO 11 Jl fo -(-- %. , IIMOE N USA USING OOMIESIC AND n ee RAIS "...well above average in the important per- The Sylvania RS4744 We can afford to be very forward about our back. Because the back of our RS 4744 stereo receiver is one of the most versatile you'll ever see. We've got phono inputs for two different turntables. And two sets of tape monitor input and output jacks. And terminals for main speakers, remote speakers, and PQ4 speakers. And three AC power outlets, one switched and two un switched. The rest you can see for yourself in the picture above. But what's behind our back is just as impressive as the back itself. As Popular Electronics* put it, the RS 4744 "met or surpassed all the published specifications we were able to test" and was formance aspects." Take power, for example. Popular Electronics found the RS 4744 "conservatively rated" at 60 watts per channel, min. RMS at 8 ohms from 20Hz to 20kHz with no more than .25% Total Harmonic Distortion. Which made it "outstanding for a receiver in the RS 4744's price range." FM 50 dB quieting sensitivity was equally impressive-"a very good 3µv in mono and 350 in stereo." But don't take our word for it. Or their word for it. Go see the RS 4744 for yourself. Back or front, any way you look at it, the RS 4744 is one fine stereo receiver. `popular Electronics, December 1974 Issue. CUD SYLVANIA Check No. 17 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com Power Output vs. Frequency Ideally, for a fixed amplitude input signal, a power amp should be able to deliver the same amount of output power over a wide frequency range, extending from subaudible to superaudible, say 20 Hz to 20,000 Hz. Maximum available power output can vary within these limits, sometimes dropping off substantially at the ends of the spectrum or having various peaks in between. At the ends, the power may even decrease by 50 percent or more. In fact, the frequencies at which available power is 3 -dB down (which happens to be 50 percent) at each end of the audio spectrum were called the half -power points, and they were used to define the useful power bandwidth of an amplifier previous to the FTC ruling. Under the new ruling, however, the full power of the amplifier must be available at all frequencies mentioned, with no decrease allowed at the ends of the frequency spectrum. Power Handling Capability Speakers, as well as power amps, may be treated in terms of their power-handling capabilities, just as electric light bulbs are marked 10, 60, or 75 watts. We cannot draw further parallels between speakers, amps, and light bulbs, however, because the marking on a light bulb ¡Weans that it always dissipates just that number of watts, not less, not more (provided it's being fed the nominal 115 V a.c.). However, if a speaker is rated at, say, 60 watts, that means it can handle power up to (but not exceeding) that level. It doesn't demand (as does the light bulb) that much power when it's hooked up to the amplifier. If we try to run more power through the speaker (by feeding it signals of higher voltage pressure), thus resulting in too much power being dissipated in its voice coil, one of three undesirable things is likely to transpire. Either the voice coil will move too far out 28 of its magnetic gap and stick, never to return, the voice coil may just burn out, or the speaker will just make horribly dis- torted sounds. Impedance Matching A high quality power amp will deliver its rated power provided the load (the speaker) is designed to accept this amount of power. One of the problems here is that the impedance of the speaker is not a fixed value. It varies from its nominal value all over the lot, changing as it goes up and down the audio spectrum; at 70, 80, or 100 Hz the impedance may be five times higher than nominal, and it may also measure 40 ohms or more at the high end of the frequency range. This may sound discouraging, and it is, because the result of the peak is a droop in power transfer. If the peak occurs at the low frequency end, there is a reduction in the transfer of power from the amplifier by the speaker, just where we need extra power for those deep bass notes. There is an even bigger problem with impedance dips which, if deep enough, will give the amplifier fits. Figure 3 is an impedance curve for a hypothetical loudspeaker. At about 100 Hertz this unit does indeed have an impedance of 8 ohms. However, the curve shows that the impedance of this speaker wanders all over the place, with a peak somewhere around 60 Hertz. This peak decreases the amount of current delivered to the speaker at that frequency, resulting in lowered acoustic output. Fortunately, the peak in the curve at that point is due to speaker resonance. Now, a speaker is more efficient around its resonant frequency than anywhere else on its curve. Thus, even though less current is delivered to the unit at resonance, the bass loss there isn't as severe as it might otherwise be, due to its increased mechanical efficiency at that point. Note also the severe dip in the mid -range region around 1 kHz. The low impedance at that frequency can put excessive current drain on the amplifier, possibly causing the amp's protective relay or fuse to open. Whether this happens or not will depend on the setting of the preamp's gain control as well as the signal level fed into the preamp. 24 Damping Factor 20 16 12 e 4 loo IK FREQUENCY Fig. - Hz IOK 20K 3-Impedance versus frequency response for a speaker. ------4 OHMS 8 OHMS 16 OHMS 0.8 Many speaker terminals are labelled 4-8 ohms so you might think that this represents the impedance of the amplifier. Not so at all! This is simply a direction to the installer, "Attach the two speaker wires here." There is actually a tremendous mismatch, since the internal impedance of the amp may be measured in tenths of an ohm. The ratio of the impedance of the amplifier to the speaker's voice coil impedance is called the damping factor, which describes the amp's ability to control or minimize unwanted, residual speaker movements such as hangover and ringing. If a speaker has an impedance of 4 ohms and the amplifier has an internal impedance of 0.04 ohms, the damping factor would be 100. 0.7 0.6 Total Harmonic Distortion (THD) The amplifier must not only deliver power to the speakers, but should do so with the least possible distortion. To indicate that an amp has a certain amount of THD at a particular frequency is analogous to saying that an auto gets 18 0.5 0.4 0.3 0.2 0.1 - 100 10 OUTPUT Fig. WATTS 4-Intermodulation distortion versus power output for three impedances. miles per gallon when moving along at 10 MPH. But what about 40 MPH, or more relevantly, 60 MPH? An amp that is listed as having less than 1 percent THD at 1 kHz could easily have several percentage points of THD elsewhere in the sound spectrum. With amps it is best to know the maximum THD over the entire frequency range at maximum power. Then you can be certain that at most frequencies and power AUDIO DECEMBER, 42 www.americanradiohistory.com AmericanRadioHistory.Com 1975 Celestion loudspeaker specialists NewCelestionUL6.Com pact enclosure provides 35 Hz -29 kHz overall res- ponse; =3.5db80Hz-20 kHz. Power handling 20 watts continuous RMS sine wave. Can be with amplifiers up to 80 watts RMS per 1924 Il . --- 1 ;7 used, = channel..- UL6 e d New Celestion UL8. Overall response 30 Hz -28 kHz; = 3 db 70 Hz -20 kHz. Power handling 25 watts continuous RMS sine wave. Can be used with amplifiers up to 100 watts RMS per channel. since '' 9 4f o I'' l' UL8 res," New Celestion UL10. Overall ponse 20 Hz -40 kHz; +2 db 40 Hz -20 kHz. Power handling 50 watts continuous RMS sine wave. Can be used with amplifiers up to 200 watts RMS per uulo channel. I ° ` ¡ 1 j . , I 33 New Celestion Ditton 33. Overall response 40 Hz 28 kHz; +3 db 60 Hz -20 kHz. Power handling watts DIN continuous. DITTON Ditton 44 Monitor. Power handling 44 watts DIN continuous. "It could take 100 watts (at 300 Hz on a steady-state basis) to produce an output of 106 db, and a power pulse of 486.5 watts (973 watts peak) to yield an output of 116 db. These figures attest to both the Ditton's robustness and to its excellent " -High dynamic range DITTON Fidelity, June 1973. . . 33 , ,= \-J . Ditton 66 Studio Monitor is top of Celestion Ditton Series and has received rave reviews worldwide. Appointed "Reference Standard" by "Revue du Son" of France. Features 16 Hz -40 kHz overall response, ultra -low distortion, high efficiency. Power handling DITTON 80 watts DIN continuous. 44 66 -.1 Also available: Ditton 15 "Bookshelf Classic" Ditton 25 floor standing luxury loudspeaker The following quality drivers, used in the 8 models listed above, were totally researched, designed, and built by Celestion-Britain's most experienced loudspeaker manufacturer. HF2000 HD1000 HD700 MD500 MC5 MC6 BASS UNITS ABR's pressure -dome supertweeter specified for B.B.C. monitors. New 1" pressure -dome tweeter ensures extended treble response, excellent dispersion and complete freedom from listener fatigue. New 2" pressure -dome midrange unit. 2" soft -dome midrange unit covers 500 Hz-5kHz with very low distortion, exceptional dispersion. Extremely powerful magnetic field ensures critical damping and high power handling. New 5" midrange unit with low mass fibrous cone for outstanding transient response. 3/4" 6" plasticized midrange unit in damped hermetically sealed transmission line. UL bass units have 1.5" voicecoil, massive magnet system and specially treated Bextrene diaphragm. Ditton bass units have specially plasticized fibrous cone to prevent resonances; neoprene roll front suspension permits long linear axial movement for low distortion bass reproduction. Auxiliary bass radiators ensure excellent bass response, raise sensitivity, and reduce distortion to negligible limits. Sole North American Distributors: ROCELCO INC. 160 Ronald Dr. Montreal, Canada H4X 1M8 Phone[514] 489-6842 Los Angeles: (213) 985-5707 Chicago: (312) 381-4559 New York: (516) 938-4057 Check No. 10 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com levels there will be less distortion than maximum-a reassuring feeling. Distortion is also related to the power output in watts (Fig. 4). Maximum distortion appears at the maximum power output of the amplifier, where waveform clipping begins to take place as the distortion rises sharply. Figure 5 shows percentages of total harmonic distortion for 4- and 8-ohm arrangements working single channel and dual channel. THD is a main limiting factor in power amp ratings. If there were no specified THD, then power output would become a "numbers game" and have no real meaning. The power specification of amplifiers, then, must list, in addition to THD, the sine wave continuous or average power output, in watts per channel, for each load impedance, with all channels driven, and with the power bandwidth in Hertz. Frequency Response At one time the frequency response of an amp was a sacred cow, and for good reason. The amp, in in those olden days, was about as guilty as the phono cartridge (or other signal source) or the speaker in contributing to degradation of sound. But not any more, so far as amps are concerned, since the frequency response of a quality amplifier can range from a low of 7 Hertz or so to a high of 80 or more kHz with a variation of +0, -1 dB, usually measured at a 1 -watt level. Now that is a mighty flat response. When plotted on a graph, it looks as though it was drawn with a straightedge. But before you clap your hands with joy, consider that the load (the speaker) has a response curve quite different-more like a mountain range. --- 0.8 0.7 SINGLE CHANNEL DUAL CHANNEL 0.6 8OHMS 0.5 4 OHMS I I 0.4 1 I I 0.3 1 / r I 0.2 -4 0.1 lo OUTPUT 100 -WATTS 5-Total harmonic distortion versus power output for two impedances, showing effect of single- versus dual channel operation on power output. Fig. +3 +2 +I 0 OWER BANDWIDTH ,./... AT 150 WATTS -2 3 +1 Q I -WATT FREQUENCY RESPONSE I 10 11111r 111111 IK I0K IOOK FREQUENCY- Hz Fig. 6-One-watt frequency response and bandwidth power for a 150 -watt amplifier. at full And if you are going to use low and high filters and tone controls before the signal reaches the main amp, getting terribly perturbed about a 1 -dB variation in an amp's frequency response is fretting unnecessarily. This doesn't mean you shouldn't pay attention to frequency response. You should, for having an amp with a flat frequency response eliminates an undesired variable from at least one component. But it does not mean you are automatically guaranteed an equally automatically faithful sound output. High fidelity is more than a goal; it is a proper perspective. (See Fig. 6). Two -Channel Amplifiers Stereo amps are two-channel devices, that is, two amplifiers built on one chassis, with the power supply for both also on that chassis. In the past specification sheets often indicated the total wattage of both channels when specifying power output. Usually, too, there is less power available when both channels are driven simultaneously, than if one channel is operated alone. The new FTC power statement ruling requires that they be stated per channel and with both channels driven at once. Amplifier Protection Circuits At one time speakers were isolated from the output stages of the main amp by transformers. These devices transferred the audio current to speaker voice coil while they blocked d.c. current (coming from the power supply). The main amp needs d.c. for its transistor elements and gets this from the power supply. What the speaker voice coil requires, however, is an alternating current whose waveform resembles that of the voltage signal input to the main amp. But while transformers perform the separation function admirably, they are frequency -sensitive devices and so pass some frequencies on easily to the loudspeaker while impeding others. A direct -coupled stage, now used in most modern amps, is one in which the output stage is directly coupled to the speakers. A problem arising from this practice is that failure of an output transistor may produce a heavy flow of current though the speaker's voice coil, damaging or destroying it. Another possible cause of trouble can be damage to the transistor amplifier tutput stage caused by a short circuit across the speaker leads. To prevent these problems, amps now have a variety of protection circuits which shut down the power amp at the first sign of trouble. These can be simple thermal fuses or complex circuits which detect any severe drop in output load impedance, especially a short circuit. Some power amplifiers use protective relays which can open the connection between the amp and the speakers, a somewhat more expensive arrangement than a simple fuse. Silicon controlled rectifiers (SCRs), which are faster and thus protect more quickly, are also used to protect the output stage. Still other and even more sophisticated circuits sense the levels of voltage and/or amperage and can shut down the amplifier very quickly should an excessive level of either occur. Yet another form of protection exists in the speaker relay found in most amplifiers and receivers nowdays. You've probably noticed the few second delay between the time the unit is turned on and when sound begins to be produced by the speakers; this is the action of the relay, which prevents transient current peaks which occur at turn -on from reaching and possibly damaging the speakers. Speakers and power amplifiers are hi fi's electronically married couple. They not only work together closely, but the actions of one affects the other. It is this relationship we will explore in the next installment. AUDIO 44 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 Introducing one of the finest collections of in the world: the MX1580. receivers stereo the Sherwood 7900A. Sensitivity* the Pioneer of the Power* Sony 7065. FM of 838. Selectivity* of Capture ratio:`of the Marantz 2270. Total Harmonic Dist. rtionv of the JVC VR -5660. OCL direct -coupled d_fferen:ial The oldest new company Wit r sc many excellent AM/FM for extended frequency amplifier in the business. steren receivers around these response and wide bandwidth days.who needs another:' Sc Although we're a completely instead of making just "anotter" separate greet.), we were able to Power 60 watts we collected the east significant specs and useful features of five of the best, and "combined" them in one: the MX 1580. course, same of these fve receivers have features Jill one doesn't have (we think you can mancge without two phonoirt_L.ts). But then, ours has features they 1cn't have; features yot: tí shoti.dn't do without. Yeu pay for-and getwhat you really need. The MX 1580 has exclusive ASNC. which automatically reduces the noise level on weak stereo stations without reducingseparation an strong ones. And special taermal prctecton for output transistors and the power _ransformer. Plus lots more we were able to. include and, at $.479.95t,'save you` few bucks in the bargain. How? It wasn't easy. But we had he.p. drawon therescurcesof a company that's been a leader in the ndustry since 1915. So we could afford to wait until we had the 2OHz-2CkHz MX 1580 r_ghr. And now it's so right, we insist that every single one be inspectec twice before i_'sshipped. After all, we have one of the world's finest stereo collectians to protect. Features and Specs? Sensitive front-end with three dual gate MCSFET's and 4 -gang tuning capecitotr. Twa 6 -pole linear phase filters improved electivity and phase response High gain IC quadrature FM detector. Switchable signal -strength/ center -tuned meter. Phase lock loop IC circuit for FM stereo multiplex. Computer designed low pass audio filters foi-suppression of ultrasonic frequencies. fr Chet No.23 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com per channel, min. RMS Power Bandwidth .... Total Earmonic Distortion Load .. _ . 0.5% 8 ohms IM distortion 0,8% Frequency response .. 201-1z-25kHz Usable sensitivity (IHF) ....1.8uV Selectivity I IHF) 7 dB 1. çdB Capture ratio (IHF) 50dB signal: to noise m0113 : 2.5uV 50dB Stereo separation @ _kHz 40dB @ 10kHz _ _ All specs suh'.ect to :lunge witlout iotice. çecs of comjetitive receivers -aker froth rnanuf lcturers own published data sheers. *`Manufacturer's stmested retail price; optional with dealer. We're being heard from. MX High Fi at,/ Gimponents, Ft. Wayne, Inc lama 46804 Equipment Profiles Realistic (Radio Shack) Model STA -225 ) ) MANUFACTURER'S SPECIFICATIONS FM Section IHF Sensitivity: 1.9 µV. S/N Ratio: 65 dB. Capture Ratio: 1.2 dB. THD: Mono, 0.6%; Stereo, 0.8%. Image Rejection: 70 dB. AM Section Sensitivity: 250 µV/M, internal antenna. Image Rejection: 55 dB. Amplifier Section Power Output: 50 watts per channel into 8 ohms from 20 Hz to 20 kHz (continuous); THD over entire power band, no more than 1.0%. IM Distortion: Less than 0.6%. S/N: Phono, 60 dB; Aux, 70 dB. General Specifications Dimensions: 19-1/8 in. W x 5-3/4 in. of the panel. When illuminated, the dial area displays a linear FM frequency scale, a 0-100 logging or reference scale, and an AM frequency scale. To the right is a single signal -strength meter, adjacent to which are the illuminated words "Auto Magic" about which we will speak shortly. A good sized tuning knob is located within the blacked -out dial area as well. Two slide controls at the extreme right operate vertically to control volume level for each channel, thereby eliminating the need for a separate balance control. If input program sources are balanced, the two sliders can be operated in unison with a single finger-a nice touch that works as well in practice as in theory. Below the dial scale area are a phone jack (at the extreme left), seven small push -buttons; dual -concentric clutch -type bass, mid -range, and treble controls; a program selector switch; a dubbing -out jack, and a tape input jack (these are in addition to the usual tape monitoring in and out jacks on the rear panel). A speaker selector switch also turns on power, selects main or remote speakers, or chooses Radio Shack's "Quatravox" passive decoder circuit which synthesizes a four -channel effect from two -channel sources and is not unlike the Dynaco matrix introduced during the earliest days of four-channel excitement. Those seven push buttons mentioned above take care of such things as switching on the Auto -Magic feature, introducing low and high filter circuits (at a 6 dB/octave slope rate), activating the tape monitor circuitry associated with the rear panel tape jacks (to gain access to the Tape 2 front panel jack, the main program selector must be switched to the Tape 2 position), loudness circuit activation, mono stereo switching, and tone control bypass or defeat. The rear panel of the STA -225 has screw -terminals for connection of two pairs of speakers, with pin -jacks paralleling the "main" speaker terminals in case your speaker systems come equipped with cables and built-in phono es AM/FM Stereo Receiver ) i H x 15 in. D. Price: $399.95. There is a good deal to commend in this Realistic stereo receiver distributed by Radio Shack stores, but at the same time we surely would like to have seen Radio Shack give more than a minimum number of specifications. After all, not every prospective buyer gets a chance to read an equipment profile in Audio to find out what phono cartridge output matches up best or what the input sensitivities of the AUX and Tape Inputs are. With too many other firms, such a scarcity of specs suggest poor performance, yet in This case Radio Shack is hiding its light under a bushel since the parameters we measured turned out too good to hide. The STA -225's front panel has the now -familiar long, black-out dial area, which occupies all but a couple of inch- nnuuuuunnuutulc.::1t11:iuuuri Fig. 1-Rear panel. Fig. 2-Interior view. AUDIO DECEMBER, www.americanradiohistory.com AmericanRadioHistory.Com 1975 plugs. Antenna screw terminals are provided for 75 -ohm, 300 -ohm, and external AM antenna connections, and would you believe that this $400.00 receiver has one of those "ca- pacitor clips" that couples the line cord to one of the 300ohm terminals to serve as an indoor FM antenna? Since this rather minimal antenna arrangement does a poor job of rejecting multipath, we disconnected the clip for our tests and connected an outdoor FM antenna. Tape out and in jacks, AUX inputs, and phono input jacks are arranged between the speaker terminals and the antenna connections, and a switch near the phono jacks selects high and low input sensitivity. The rear panel also has a pair of a.c. convenience outlets, a line fuse, and a pivotable ferrite bar AM antenna. The rear panel is shown in the photo of Fig. 1. Circuit Features The chassis layout and circuitry of the STA -225 is shown in 2. All tuner parts, including the AM and FM stereo decoder sections, are contained on a single large PC board. The other three major PC modules contain the preamplifiers, the tone control circuitry, and the main power amplifier circuits. The FM front-end is equipped with a four gang tuning capacitor, an FET r.f. amplifier, and bi -polar oscillator and mixer stages. FM i.f. circuitry includes four IC stages (each tuned to 10.7 MHz with a ceramic filter between stages), a bi -polar input stage; and a conventional ratio detector. Multiplex decoding is accomplished by a single IC which utilizes the well accepted phase -lock loop approach to stereo demodulation. Several additional stages Fig. Friiu 11i1111u1151 To FiruÍEuriiffs Len Feldman MANY of our readers may already know, new standards for measurement of FM tuners and receivers were recently approved by the three major electronic organizations in this country, The Institute of High Fidelity, The Electronic Industry Association, and the Institute of Electrical and Electronic Engineers. Many new measurements of FM products are now called for in the new standard, including a host of previously omitted performance specifications having to do with stereo FM performance.(We will publish a definitive article on the new standards in the near future; meanwhile, those interested in the new standard can obtain a copy by sending $6.00 to the Institute of High Fidelity, 489 Fifth Avenue, New York, N.Y. 10017 and requesting a copy of Standard IHF-T-200, 1975.) One important change in terminology needs a bit of explaining right now, since our test reports dealing with FM products already reflect the use of this term -the dBf. dBf stands for "dB referred to 1 Femtowatt" and, for the univery small power nitiated, a Femtowatt is 1 x 10-15 watts figure indeed. The new standards require that signal strengths, formerly given in microvolts, now be given in actually in dB referred to 1 Femtowatt. terms of power The purpose of this change is to avoid certain ambiguities which were possible so long as the "microvolt" was used. It is the power of an incoming radio signal that really counts, and power involves a voltage developed across a known impedance. Clearly, 2 microvolts across 75 ohms represents exactly twice as much power as 2 microvolts across a 300 -ohm impedance (P = Ez/Z). A manufacturer who chooses to measure his microvolts by feeding them into the 75 -ohm antenna terminals of his FM product will therefore come up looking twice as good (or having half as much signal requirement) as a competitor in terms of such specifications as usable sensitivity (IHF sensitivity), 50 -dB quieting signal, stereo threshold signal strength, etc. By converting to statements of power rather than voltage, such ambiguities are eliminated, since power is power no matter what the impedance involved. The new dBf system AS -a -or AUDIO DECEMBER, will take some getting used to, and in fact, in our test reports of FM product performance we plan to give both µV numbers as the reference, and the resulting dBf numbers that correspond when the most popularly used 300 -ohm antenna terminals are used. To determine the dBf value for microvolt readings not listed (assuming a 300-ohm impedance and the old IHF "terminated" microvolts), the following formula should prove useful: dBf = 20 log io 5 0. in which µV equals the number of "terminated microvolts" you wish to translate to dBf. Table I: MicroVolts versus dB re "Familiar" Microvolt Readings (across 300 ohms) 1.6 1 Femtowatt. Equivalent dBf 9.28 1.7 9.80 1.8 10.30 1.9 10.77 2.0 11.21 2.1 11.64 2.2 12.04 2.5 13.15 2.7 13.82 3.0 5.0 14.74 19.17 7.0 22.09 10.0 25.19 100.0 45.19 500.0 1000.0 59.17 10,000 85.19 105.19 100,000 1975 www.americanradiohistory.com AmericanRadioHistory.Com 65.19 are employed in connection with the aforementioned Auto Magic feature of this tuner section. When the user touches the tuning knob, an a.f.c. circuit is defeated, enabling you to accurately tune in desired FM stations (by ear, since the tuning meter acts only as a signal -strength meter). Releasing the tuning knob turns on the a.f.c., which then "pulls in" to center of channel, according to the instruction booklet. While we generally do not favor a.f.c. circuits, we must comment that during our distortion measurements, we weren't able to improve upon the "lock in" of this circuitry, which did home in on the miriimum distortion point of received (or generated) signals. We found, too, that unlike less so - o - 10 IIIIIiImIllllllfIllllllilmIllllliIIIIII 1111111,/11111111111511111115111111IM111111 !...:nllllM11111113III1111 STEREO THD 0.5% 1111 - 30 10111III:III1111111111 MONO THD =0.15% 111111 - 40 Tuner Measurements Major tuner performance curves are shown in 30 = - 20 lo a° IIIIIII \11lIIIIQ111111111111111Z111114111 IIIIIIIMMIfilljiBrìiiiiilTGiiiliilaTiiilii 111111111l011135MIM!4!!IML1l4!! - 70 IIIIIIIs11111111`11IIIIIIiii_i::::!ll""O - 60 - 80 EIIIIIIIIIIIIIIII1III11111111111e1t111i1111 iII 11 01 MONO S/N _ 72dB ;1111111 = 67dB all 11111131111111111111111111 STEREO S/N I.0 10 IK 00 INPUT - I0K MICROVOLTS ACROSS 300 OHMS Fig. 3-FM quieting and distortion characteristics. "L" INPUT, "12 OUTPUT 0 - 10 -20 3.0 -30 2.5 'L INPUT,"R"OUTPUT - 40 - 50 Amplifier Measurements STEREO THD 10 ..` 4. 100 10 20 15 \` MONO THD IK FREQUENCY 10K At mid -frequencies, the STA -225 delivered 57.3 watts for harmonic distortion of 1.0%. At rated output (50 watts per channel), a 1 kHz output signal contained only 0.147% THD and IM measured 0.33% for this same output level. The rated 0.6% IM was reached at a power output level of 58.6 watts. At all lower output levels, THD and IM were both well below the 0.1% mark, as shown in the curves of --i0.5 its rated 20K -Hz Fig. 4-Separation and distortion versus frequency. Fig. 5. Distortion was well within FTC limits over the entire frequency band, measuring 0.3% at 20 Hz and 0.63 at 20 kHz. In order to meet claims, the unit could have had as much as 57.5 W(THD) 0.9 ALL CHANNELS DRIVEN 8 -OHM LOADS INPUT: KHz FOR THD READINGS 0.8 Fig. 3. IHF sensitivity in mono measured 2.6 µV (equivalent to 13.7 dBf), while in stereo, usable sensitivity measured 6.0 µV, or 20.9 dBf. The 50 dB quieting peak in mono was attained with a signal input of 3.0 µV (14.93 dBf), while in stereo the same level of quieting was reached with a signal strength of 24 µV (33 dBf). Ultimate S/N in mono was 72 dB, while in stereo, maximum quieting measured 67 dB. Mono THD measured a low 0.15%, but was 0.5% in stereo for the same 1 kHz audio signal at full modulation. Capture ratio measured 1.5 dB, while selectivity (alternate channel) was 70 dB as claimed. Image rejection was 73 dB, a bit better than claimed. Muting threshold (which is not adjustable by the user) was a bit higher than we deemed necessary, allowing signals to break through at levels of 10 µV (25.4 dBf). Stereo switching occurs at signal inputs of 6.0 µV (20.9 dBf) or higher -a well chosen threshold that corresponds exactly to the signal strength required to obtain usable stereo sensitivity. As shown in the graph of Fig. 4, stereo separation was in excess of 40 dB from 50 Hz to 2 kHz, decreasing to 28 dB at 10 kHz. Distortion at frequencies other than mid -band are also shown in this graph. - 50 1111111111111111111111 phisticated a.f.c. circuits, the presence of this circuit did not prevent us from tuning to weak stations which were fairly close to strong ones. Obviously, not all a.f.c. circuits are alike, and the one in the STA -225 is worth having. Preamplifier -equalizer circuitry uses discrete devices (two per channel), and the tone controls are of the conventional feedback type. We were delighted to note that each of the slide -volume controls contains two potentiometers-one just ahead of the tone control -circuitry, the other at the input to the power amplifier section. This arrangement makes for best signal-to-noise at any listening level. The main power amplifier circuits feature direct coupling from input to output, a differential input stage, and complementary symmetry output stages. Also included is automatic circuit protection/amplifier shut-down circuitry which will trip if the amplifier is overdriven into too low a speaker impedance. I 0.7 58.6W(IM) 0.6 56.5 0.5 W (THD) BOTH CHANNELS DRIVEN 8 OHM LOADS 0.4 0.8 0.2 0.6 0.1 0.4 0.2 0 0.1 0 10 POWER OUTPUT/CHANNEL 100 IK -WATTS 0 100 IO IK FREQUENCY Fig. 1.0 0.3 5 -Harmonic power output. and intermodulation distortion versus Fig. - IOK 20K Hz 6-THD versus frequency. AUDIO 48 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 \VSB SO CL-A\ I A\DAL Our two-way speaker systems ADS L400, L500 and L700 were developed right along with our more expensive studio speakers for the best possible reason: we wanted to create a coherent line of loudspeakers where every model, regardless of price, would have to reproduce musical sound with an optimum of clarity and a total ab sense of coloration. When our engineers finally were able to meet these criteria, we called this re- markably open quality the 'Invisible Sound' of ADS. Since its introduction only two years ago, it has become the standard of excellence for many professionals and dedicated audiophiles. Our lowest priced speaker, the ADS L400, costs less than $100. Yet it shares with all other ADS systems the 'Invisible Sound' and the technical refinements that make this faithful response to the input signal possible. For instance, we install only one type of soft -dome tweeter, a masterpiece sophisticated audio design. Also, all ADS speakers utilize similar small -diameter woofers and the same computer -grade materials for the crossover networks. The craftsmanship and materials that go into every cabinet are of uniform, high quality. When you listen to one of our two-way speakers for the first time, please note how the virtually massless tweeter meticulously renders every treble detail. Discover how smoothly the woofers take over the midrange frequencies, feel the strength and precision of their compliance to a sudden bass signal. As a total value, we believe the ADS L400, L500, and U00 are without competition in their respective categories. Your local ADS dealer will proudly prove this claim in his sound studio. Take the time to test our speakers critically. Take the step beyond transparency. Experience 'Invisible Sound.' It will then be impossible for you to in accept anything less. Analog & Digital Systems, 64 Industrial Way, Wilmington, Massachu- setts 01887. as L700 www.americanradiohistory.com AmericanRadioHistory.Com 400C-76 PG 1.0% THD at either of those two frequency extremes, and is therefore conservatively rated by any standards as far as audio power output is concerned. A plot of distortion versus frequency for full rated (50 watt) output is shown in Fig. 6. Phono input sensitivity measured 1.5 mV in the "high sensitivity' position of the phono rear panel switch and 2.5 mV in the "low" setting. Overload of phono inputs took place with signal inputs of 180 mV or 90 mV, again depending upon the setting of the phono sensitivity switch. Hum and noise was generally much better than claimed, measuring 67 dB for phono (referred to the 2.5 millivolt input sensitivity and full output) and 76 dB in the high-level AUX setting. Input sensitivity for the AUX input measured 200 mV for full rated output. At minimum volume control settings, residual hum measured 102 dB below full output. Overall frequency response of the amplifier section was flat within 1 dB from 20 Hz to 20,000 Hz. Having recently acquired a spectrum analyzer in our laboratory, we decided to display tone control characteristics "live" instead of plotting them on graph paper. The photo of Fig. 7 is a composite, taken by producing sequential frequency sweeps from 20 Hz to 20,000 Hz. Each sweep is retained on a storage oscilloscope so that by successively boosting and cutting the bass, treble, and mid -range controls on the Realistic STA -225, we were able to assemble this composite display and record it photographically. Beats pushing a pencil on graph paper anytime, and it's far more accurate since every point is shown, instead of the relatively few points we usually take to plot a "continuous" pencil curve. Inspired by the results (you may expect to see much more sophisticated applications of spectrum analysis in future test reports, including analysis of the spectral content of harmonic distortion), we decided to "plot" the action of the loudness circuit on our rather expensive version of an "etch -a -sketch" toy and the results, for reader's amazement and amusement, are shown in the 'scope photo of Fig. 8. As you can see, the loudness circuit is continuously variable, but what isn't readily apparent is that the circuit is tied in through the volume controls-an interesting arrangement. Listening and Use Tests Fig. 7-Bass, midrange, and treble control range shown on spectrum analyzer sweep display. (Scale: 10 dB per vertical division.) 500H: 'kHz : i! FREQUENCY (LOG¡ Getting back to the STA -225, we hooked it up to a pair of low -efficiency, air -suspension speakers and put it through its paces. FM performance was quite good and, if you were wondering about the absence of a stereo indicator light, rest assured it was not forgotten. The dial pointer itself changes color (it glows a bright red) whenever a stereo signal is intercepted on the FM dial. Controls are easy to use and good to the touch, particularly those dual slide volume controls. The mid -range tone control is a useful feature usually found only on separate preamps and amps or much more expensive receivers. Sometimes called a "presence" control (because it can be used to enhance vocalist's sounds and to "bring the vocalist forward" in the stereo sound field), its range in The STA -225 is just right for its intended purpose-about +5 or +6 dB at maximum rotation. After satisfying ourselves that the STA -225 performed well with our test speakers and a variety of program sources, we attached two more speakers and switched to the Quatravox mode. Depending upon the recordings used, synthesized four -channel effects ranged from barely audible to highly pronounced. Certainly, this circuit isn't intended to substitute for true four -channel but it is of some interest, especially if you own a large record collection and have some discs with sufficient out -of -phase "ambience" information to show off the passive circuit to its best advantage. In summary, the Realistic STA -225 offers a great deal of value for its modest (these days) price of under $400.00. Power output is solid all the way down to the nether -bass regions, and there was no evidence of excessive heat at the output stages even after several hours of use at loud volume levels. Perhaps Radio Shack is right in promoting the receiver for the more casual user by omitting some important specs and treating the connection panel in a "compact system" way, but we think the audio enthusiast seeking 50 watts per channel has graduated from that level and expects a more audiophilic approach to product presentation. When it comes right down to it, the STA -225 is just too good for anything less than an enthusiastic treatment from its Leonard Feldman makers and distributors. 8-Action of loudness control shown on spectrum an alyzer sweep display. (Scale: 10 dB per vertical division.) Fig. Check No. 90 on Reader Service Card AUDIO 50 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 A tribute to appreciation. Music appreciation. Art appreciation. Appreciation for excellence in performance. A fulfillment that comes from the experience, not from the parameters by which it was created. The Contrara Group of loudspeakers is a tribute to that appreciation. We should not deliberate how Amilio Contrara has sculpted the walnut, blended it with cloth and merged it with technology to bring visual satisfaction. Nor, how he has balanced the electronics with physics to provide audible gratification. Ours is only to enjoy. To appreciate, To savor. Something only our ears and eyes can savor for themselves. If you enjoy your music and quality craftsmanship, you'll appreciate the Contrara Group; it's a tribute to your sensitivity. Write us for additional information. We'll send you a booklet on appreciation and a list of locations where you can enjoy Contrara. 1ENNINGS RESEARCH CIRCLE 25 ON READER -SERVICE CARD Fair Oaks INC ö Pasadena,GROUP, Calif.ro3 le,Onnti Canadian THE AUDIO For name of nearest dealer, call toll free area code (800) 447-4700. In Illinois, call (800) 322-4400. www.americanradiohistory.com AmericanRadioHistory.Com I,'11 "III IIII (DOLBY NR ) ( RECORD ) I 2 I BIAS -- 10- 9- L STOP PAUSE RECORD www.americanradiohistory.com AmericanRadioHistory.Com EQ - lo -9 10 9 performance and reIiabiIitj ... ? TEAL how con you really afford anything less At TE AC, our fundamental mandate for any new product is performance and reliability. First and finally. Qualities that are measurable in terms of mechanical stability and inherent design integrity. These are essentials. Because our technological resources established the cassette deck as a true high fidelity component. So we demand that a new product possess that measure of TEAC quality. And that's what distinguishes the A-170. Compare it with other inexpensive cassette decks, please. Just call (800) 4474700* for the name of your nearest TEAC retailer. We think you'll agree it's a value you can rely on. *In Illinois, call (800) 322-4400. A-170 TEAC® The leader. Always has been. TEAC Corporation of America/7733 Telegraph Road, Montebello, Ca. 90640/©TEAC 1975 Check No. 51 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com Technics T-400 Speaker System MANUFACTURER'S SPECIFICATIONS Frequency Response: 38 to 20,000 Hz ± 3 dB, down 10 dB at 28 Hz, free field. Dispersion: 180° at 10 kHz. Impedance: 8 ohms. Drivers: 12 -in. woofer, 5 -in. midrange, 3' -in. tweeter, two angled 2 -in. super tweeters. Crossover Frequencies: 700 Hz, 3 kHz, and 7.5 kHz. Enclosure: Oiled walnut finish, fully sealed. Dimensions: 27 in. H x 15 in. W x 13 y, in. D. Shipping Weight: 53 lbs. Price: $279.95. Technics by Panasonic is not new in high -quality consumer audio. One of the better loudspeaker systems made under this trademark is the Model T-400, a four-way, five driver system intended for floor mounting. The enclosure measures 68.6 cm. H x 38.1 cm. W x 33.7 cm. D. (27 in x 15 in. x 13 1/4 in) and weighs 24 kg. (53 lbs.). The sides and top are finished in oiled walnut, and a colorful sculptured foam and cloth grille accents the darker wood tones. Since the T-400 is generally intended for mounting adjacent to a wall, the rear of the cabinet is stained but not furniture finished. Speaker connection is made to two well -marked terminals in a recessed cavity on the rear of the enclosure. Tweeter and midrange -level switches are placed directly above the terminals. Each of these is a two -position switch, with the up position corresponding to normal equalization and the down position corresponding to a 3 -dB level reduction. A 30.5 -cm (12 -in.), high -compliance woofer is mounted on the bottom of the front panel and works into a sealed enclosure. A 13 -cm (5 -in.) midrange driver and 9 -cm. (31 -in.) tweeter share the central portion of the front panel, while two 5 -cm. (2 -in.) super tweeters are mounted at the top, angled away from the front axis for broader dispersion of the highest frequencies A very clearly -written instruction manual accompanies each speaker. this represents the greatest impedance variation that will be seen by a power amplifier. The highest impedance is presented when the midrange and tweeter switches are both in the down or low position. The lowest impedance occurs for the switches placed upward. The T-400 is rated at 8 ohms, and the lowest value measured was approximately 7 ohms. The polar impedance plot for the downward switch positions is shown in Fig. 2. In a sense, this polar measurement is a duplication of the impedance plot of Fig. 1. However, Fig. 1 is a plot of the magnitude of impedance and is a rapid overall look at the highest and lowest values of impedance and how they relate to frequency. Figure 2 goes a bit further and shows the nature of load which the speaker presents to an amplifier, including where it is capacitive reactive and where it is inductive reactive. Two basic resonances exist, one at 58 Hz, the other at 490 Hz. Two worst -case capacitive -reactive loads for power amps occur at 65 Hz and 940 Hz. These are low enough in frequency that any well -designed amplifier should be capable of driving the T-400 without undue stress at high levels. To check for impedance nonlinearities, a constant -voltage sine -wave signal is applied to the speaker terminals and a spectrum analysis made of the current demanded by the speaker. Impedance nonlinearities show up as distortion of this current and indicate the nature of load which constant voltage power amplifiers must be able to control. A worst case nonlinearity in impedance was measured at the bass resonance of 58 Hz. At a constant peak -to -peak voltage drive of 8 volts, corresponding to a drive level of one watt into the rated 8 ohms, speaker -drive current measures 3.2 % second harmonic content (106 Hz) and 1 % third -harmonic content (168 Hz). With the drive voltage increased to ten watts, the second harmonic rises to 5.5 % while the third harmonic drops to 0.8 %. While this indicates a small amount of magnetic field nonlinearity in the woofer for moderate cone excursion, the load current can be readily controlled by any well -designed amplifier, since it occurs at such a low fre- quency. The free -field (anechoic) frequency response is shown in Fig. 3 for the amplitude of sound pressure at one -watt drive and a one -meter axial position, and in Fig. 4 for the phase of + 20 + 10 w Measurements Impedance as a function of frequency is shown in Fig. 1. The two extreme positions of level control are plotted since > z á U V o Q z w 1.....* 230Hz 20Hz 0 30 10 J 20kHz 490Hz RESISTANCE 58Hz 30 20 -OHMS 0Hz TWEETER LOW MIDRANGE LOW w w > 1111 TWEETER HIGH MIDRANGE HIGH I 1111 0 I 100 10K 1K FREQUENCY Fig. ¡ 10 2kHz 20 55Hz 50Hz 48Hz - 1-Impedance versus frequency. 20K 1 rzI- 60Hz 20 65Hz V < awácc 30 Hz Fig. 2-Complex impedance polar plot. AUDIO DECEMBER, 54 www.americanradiohistory.com AmericanRadioHistory.Com 1975 Phase Linear,; 8,515,200 wits r~r ......+ Xr,.: teem Back in '71 Phase Linear was Bob Carver, an audiophile with 200 square feet in the basement of an A & P store in the Pacific Northwest and one all-consumiig obsession to design and build the world's most powerful stereo amplifier. Today Phase Linear Corporation is an acknowledged leader in high power technology, selling a complete line of amps and pre -amps throughout the world, operating out of one of the most advanced stereo component plants in the industry. Phase Linear is now a household word among serious listeners, a word synonymous with power. quality, reliability and way -out -front technology. And Bob Carver. Steve Johnson and A. P. Van Meter have come to be rec.jgnized as the gurus of state-of-theart amplifier design and development. Phase Linear has dispensed over 81/2 million watts of power to music lovers everywhere starting with the famous super reliable virtue li distortion free Phase Linea- 700, the first successful 700 watt amplifier The popular Phase Linear 400 watt amplifier quickly followed. -he incredible Phase Linear 4000 preamplifier was then perfected followed by a smaller version, the Phase Linear 2000. Recently the Phase Linear 1000 Noise Reduction System was added to the line .. and there are many more advanced products in the wings. Technological milestones along the way have included a unique Amplifier Protection Circuit (Patent = 3.727.148), www.americanradiohistory.com AmericanRadioHistory.Com the first practical Expansion System the i-novative Auto Corralator Noise Reduction System and a unique Ambience Inject on System for pre-amps Phase Linear has come a long way from that basement lab of Bob Carvers. But products are still made one at a time and one out of every three people in production is involved in quality control or testing. And that's the way it'll be for the next 8,000.000 watts Phase Linear Corporation, 20121 48th Avenue W. Lynnwood, Washington 98036 Check No. 32 on Reader Service Card the sound pressure under the same conditions. The amplitude of sound pressure is plotted for the two extreme equalizer positions. The effect of the equalizers is approximately 3 dB, as specified by Panasonic. Low frequency response extends down to about 55 Hz, dropping off smoothly below that frequency. Response up through the range of musical instrument fundamentals is smooth and uniform. A dip in response at around 1500 Hz is followed by strengthening of the output at around 7000 Hz. The response drops rapidly above 14 kHz for an axial one meter microphone position. loo TWEETER HIGH MIDRANGE 90 HIGH I TWEETER LOW MIDRANGE LOW 80 70 60 IK 100 FREQUENCY Fig. - 10K 20K Hz 3-One-watt, one -meter anechoic amplitude response. o CORRECTED FOR MIDRANGE AIR PATH - 90 -180 CORRECTED FOR TWEETER AIR PATH -270 IK 100 FREQUENCY Fig. 4-One-meter anechoic - IOK 20K Hz phase response. 4 From the phase response, it is evident that the sound from the tweeters arrives before the sound from the other speakers in this four-way system with frequencies above 8 kHz arriving first. Shortly afterward the sound from the 2.5 -kHz to 8 -kHz range arrives to reinforce the super -tweeter signal. One -tenth millisecond later, the 800 -Hz to 2.5 -kHz sound is heard, and 0.25 milliseconds after this, the sound spectrum below 700 Hz is received. The phase response is shown for two time delays; the curve marked "corrected for tweeter air path" is plotted for the arrival of sound from 2.5 kHz to 8 kHz, the other curve is plotted for 800 Hz to 2.5 kHz arrival. The sound from all drivers above about 800 Hz is uniform in phase transition but is 180 degrees out of phase with frequencies below that. This will not be significant when T -400s are used throughout the sound system, but indicates that some care may be needed if this speaker is used for a quadraphonic addition to an existing stereo installation. The phase transitions are smooth and uniform, however, the arrival time differences make the response non minimum phase. The basic frequency response changes with off -axis angle. At 15 degrees from the direct on -axis position, the high -frequency drivers interfere with each other and create a nonminimum phase characteristic with 540 degrees of acoustic phase angle change at 6.6 kHz. The way a speaker sounds in a room is far more important to a listener than its anechoic chamber response. Figures 5 and 6 show more nearly the way the T-400 measures in a room. The unit was placed along a wall, as recommended by Panasonic, the listening position located 3 meters away from the speakers and one meter above the floor. The frequency response corresponding to the first 13 milliseconds of sound due to an impulse is shown in these figures. Both a direct front listening position and a 30 -degree left -channel -stereo seating position were measured. The curves are displaced 10 dB on this plot to prevent confusion. These measurements indicate that the T-400 will tend toward a lower pitch dominance in its timbre at around 200 Hz, a sound some would describe as "chesty." This may be partially corrected by pulling the T-400 away from the wall. The midrange level is down with respect to the extreme top end. The T-400 is definitely hotter in high -frequency response when pointed toward the listening position than when a normal off -axis stereo listening position is taken. The "chesty" sound may be somewhat offset by rotating the speakers slightly so they point more nearly toward the listening position. The effect of floor and ceiling scatter is minimal in this early sound as is shown by the similarity of this response and the anechoic measurement. 4 10dB 10de ON AXIS 1 n AXIS ON (-71 1 30° LEFT 30° CH. POS. I 100 IK FREQUENCY Fig. 10K I I I 20K IK 100 -Hz FREQUENCY 5-Three-meter "room" response, tweeter and mid - range controls in high positions. CH. I Fig. - 10K T POSLEF. 20K Hz 6-Three-meter "room" response, tweeter and mid - range controls in low position. AUDIO 56 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 To Your Taste Even the most perfect of high fidelity systems cannot escape those little inconsistencies that nag the ear. Room acoustics, speaker inadequacies, or even recording quality can produce listening environments that are less than optimum. Then, too, each person has his own tastes in frequency response that can vary from time to time, or recording to recording. Presenting the answer to your frequency response problems: The MXR two channel ten octave -band equalizer. Ten bands divide each channel's frequency response in one octave increments. Boost or subtract from the tonality of an octave spread in either channel. A gliding touch of a slide control tailors the frequency response of your system to your room acoustics. Add punch to a bass line. Or brighten up a flute solo. Precisely; repeatably. Llniquely affordable and elegantly appointed, the MXR two -channel equalizer is crafted in hefty brushed aluminum, with simulated leather and solid oiled black walnut. Its design and circuitry will compliment any modern hi-fi system with gentle elegance and imperceptble distortion. is extreme dynamic range allows for application in many situations, and it is therefore made available in a professional version with phone jacks, and a home stereo version with pin jacks and tape monitoring capabilities. instantly adaptable to your system and available at leading dealers at the incredibly reasonable price of It is $199.95. MXR Innovations Check No. 28 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com The new P by Soeisuï 00gyFM FN;TtigiO 013'---.. 9090 Tp A° qpp w N °' 104 102 100 98 h1 108 106 .. 1200 0 tied rir Ocx,BYNR/ c"diMUTING 1605 d M PX ME t0çá . SE 4 -CH ADAPTOR r,p-vs-,rr Nix kalrK :x VOLUME BP5S TAPE -BALr^sCE LOUDNESS MODE t TRIPLE TONE CONTROL SANSUI ELECTRONICS CORP. Woodside, New York PtJ TREBLE MORANGE 11377 SANSUI AUDIO EUROPE S.A., Gardena, Calfornia 90247 SANSUI ELECTRIC CO., LTD., Tokyo, Japan Antwerp, Belcium In Canada: Electronic Distributors www.americanradiohistory.com AmericanRadioHistory.Com try sOURC DECK Power, features and performance. That's what the new Sarasui 9090 stereo receiver is all about. Look what it has to offer A whopping 110 watts of continuous RMS power per channel driven into 8 ohms over the 20 to 20,000 Hz range with no more than 0.2% total harmonic distortion Twin power meters to monitor the output for each channel Advanced PLL IC Multiplex Demodulator for im- proved channel separation, eliminating distortion and reducing detuning noise Twin signal meters for easy, accurate tuning 7-position tape play switch for total creative versatility in dubbing and monitoring and many other exciting features cabinet finished in walnut veneer. All in all the Sansui 9090 represents what is probably the most advanced receiver available today. Watt for watt, feature for feature, dollar for dollar, MC LEVEL Y SELECTOR FM AUTO PHONO 1ECK -2 an almost unbelievable value at under $ 750.* Also available is the Sansui 8080 at under $650* with 80 watts of continuous RMS power under the same conditions with almost all the same features. Cabinet in simulated walnut grain. Try, and then buy, one of the new Sansui receivers at your favorite Sansui franchised dealer today. You will be glad you did. For years to come. DOLBY FM ADAPTOR AM *The value shown is for informational purposes only. The actual resale price will be set by the individual Sansui dealer at his option. aEClF2 OEGK-1 MIC caPr 2 O. 1 A Check No. 42 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com The polar energy response is shown in Fig. 7 for a horizontal pattern and in Fig. 8 for the vertical pattern. This measures the angular dependence of the total sound energy from 20 Hz to 20 kHz. The T-400 has a preferred left -versus right horizontal directivity, as shown. The sound is also directional in its vertical characteristics, with an upward launch angle that is about right for floor -mounted listening. This correlates well with the observation that the room response is similar to the anechoic response, the exception being the 200 -Hz reinforcement commonly noted for wall placement with enclosures of this size. In many listening situations, it would appear that better stereo imagery could be obtained by rotating the speakers toward the average listening location. The directional characteristics may prove to be a mixed blessing. Normal room decor will not materially affect the sound, but the stereo image will tend to "walk" with you as you move about the listening area and will also tend to constrict the area. Harmonic distortion for the musical tones El, A2, and A4 is shown in Fig. 9. Third harmonic distortion, which corresponds to the creation of the fifth in the octave higher, is stronger in the T-400 than the second harmonic for A2 and A4. At El or 41 Hz, the woofer is having some difficulty, which indicates some nonuniformity of cone motion. At 440 Hz the harmonic distortion is acceptably low, however the average position of the woofer cone moves outward from its no-signal physical location as the sound level is increased. At the maximum drive level of Fig. 9, the net displacement is 1.3 cm. at 440 Hz. This very slight breathing of average physical position with drive is very common in loudspeakers and can account for some stereo image wander under rapidly changing musical program dynamics. Intermodulation distortion was measured by mixing the tones El (41.2 Hz) and A4 (440 Hz) in equal portion. These tones are chosen because of their musical significance and 9 8 TWEETER LOW MIDRANGE LOW TWEETER HIGH MIDRANGE LOW 7 ó 1 3 TWEETER HIGH MIDRANGE HIGH 6 5 4 3 2 0 0.1 - POWER FRONTAL AXIS Fig. 100 10 WATTS Fig. 10-Intermodulation of A4 or 440 Hz by El or 41 Hz, mixed one to one. 7-Horizontal polar amplitude response. 100 TOP E2= 2nd1 El 82= 3rd J TWEETER HIGH MIDRANGE HIGH 10 E4 -3rd A3 -2nd TWEETER HIGH MIDRANGE LOW 2 E6= 3rd TWEETER LOW A4 MIDRANGE LOW mA.A111. D A5= 2nd 01 FRONT 0.01 0.1 I I 80 90 I 1 BOTTOM I WATTS SPL E1 100 , 00 90 8-Vertical polar amplitude response. r I 90 Fig. 100 10 r SPL A2 I 110 Hz I10Hz SPL A4=440Hz I 100 .41.2 1110 Fig. 9-Harmonic distortion for the musical tones El or 41 Hz, A2 or 110 Hz, and A4 or 440 Hz. AUDIO 60 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 While everyone is still trying to make V-FETS at any price,we now make them at a lower price. en Sony introduced the first amclifiers with vertical field-effect transistors last year, the reactions V were nothing short of incredible. Consumers wrote in asking where they could hear the equipment. Audiophiles demanded to know where they could buy it. And our competitors wanted to know how they could make it. In fact, the only problem was that more people couldn't afford the $1300 price. So, we at Sony decided to do something about it. And what we've come up with is our new $400 V-FET integrated amplifier, the TA-4650. The TA -4650 is quite an advanced little piece of equipment. Because the V-FET isn't just another combination of gadgets, or a souped-up version of the same old thing. It's a completely new device that combines the good points of both bi -polar transistors and triode vacuum tubes. Without suffering the drawbacks of either. Because it's made with V-FETS, the TA-4650 gives you a new level of highly defined triode sound; along with the efficiency and stability found only in solid state devices. The TA -4650 delivers 30 watts per channel, minimum RMS at 8 ohms, 20Hz-20kHZ with no more than 0.1% total harmonic distortion. It has a direct coupled power amplifier stage. As well as direct coupled FET amplifiers in the tone control and buffer stages. Its bass and treble controls have a turnover frequency selector that starts at 250HZ/500HZ for bass and 2.5kHZ/5kHZ for treble. Its volume control is equipped with a switch for 20dB muting. And it has a level control memory device so volume can be set at any predetermined point. But as good as our new V-FET amp ifier is, we're just as proud of the components we make to go along with it. Our ST-4950 AM/FM stereo tuner, for example, has a MOS FET front end, uni -phase solid state filters and IC's in IF stages. This allows an FM capture ratio of only 1.0dB, selectivity of 80dB and an S/N ratio of 70dB. The ST -4950 also has a phase -locked loop (PLL) MPX section. Which means you get excellent stereo separation and low distortion. Of course, if you're going around looking for a turntable, by all means take a look at our PS -4750 (cartridge sold separately). It has a direct drive servo motor with a wow and flutter rating of only .03%. Its base and platter are made from molded compound instead of metal, so resonance has been greatly reduced. It also has air-damped cushions, which compensate for warpness in records (again reducing resonance). The end result is a much cleaner sound. It's no accident that Sony makes the world's first commercially available V-FET equipment. Or that we have matching components good enough to complete your system. You see, we've got more solid state audio experience than anyone else. We've been at it for twenty years. For proof just stop by your Sony dealer. And use your ears. 'TA -8650:80 watts per channel, min. RMS«. S ohms, 20Hz-20kHz, with no more than 0.1% total harmonic distortion. SONY 1975 Sony Corp. of America. Sony, 9 Check No. 13 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com W. 57 St., N.Y., N.Y. 10019. SONY is a trademark of Sony Corp. because they are shared by the same driver in the T-400. The measured modulation of A4 by El is shown in Fig. 10. The intermodulation is primarily amplitude modulation with very little phase modulation. As the power level is raised, the average position of the cone moves outward and accounts, at 60 watts, for a 15 -degree static phase advance of the 440 -Hz tone due to the presence of the 41 -Hz tone. The ability of the T-400 to handle broad -band peaks such as applause, is measured in the crescendo test. A representative inner musical voice, such as A4 (440 Hz) or middle C (262 Hz), is measured by itself, and then in the presence of wideband Gaussian noise with an average power (measured over a 20 kHz band) 20 dB higher than that of the musical voice. A crescendo limit is defined when the inner voice is reduced 1 dB in level by the presence of the incoherent noise. In the T-400 the crescendo limit was reached at a peak noise power of approximately 125 watts for the tone A4, and a peak power of 312 watts for tone middle C. This indicates a moderately strong power -handling capability. The ability of a loudspeaker to provide good reproduction of transient sounds is measured with a perfect transient-the impulse. In the tests performed by Audio, the impulse response is computed from the frequency response, that is, the analytic signal is computed and its magnitude is plotted in dB versus time, in a form called the energy -time curve. The energy -time curve for the T-400 is shown in Fig. 11 for a one -meter axial microphone position and in Fig. 12 for a one -meter 30 -degree off -axis position-the direction the listener would assume in the left -channel stereo position. The super tweeters and the main tweeter are positioned on the front panel of the enclosure so that their sounds 0 10 w Z -20 w 30 40J J 3.0 35 TIME- Fig. axis. J J 40 4.5 MILLISECONDS 11-One-meter energy -time response measured on o 10 a i w o 20 coincide and reinforce, for a direct front listening position. This is shown in Fig. 11 by the single energy peak at 3.1 milliseconds. The subsequent peaks at 3.3, 3.6, and 3.8 milliseconds are reverberation components falling off at a rate of about 32 dB per millisecond. These will not significantly color the impulse behavior on -axis because of their rapid decay. The enclosure edge -diffraction components at 4.25 and 5.64 milliseonds are also well down, at levels of 28 dB below the first sound. The off -axis transient response does not fare as well as the on -axis response because of the lateral spacing between the average acoustic centers of the super tweeters and the center of the midrange and tweeter speakers. This causes a spread of energy over a range of one millisecond from first arrival. The result is a loss of clarity of sharp transient sounds and a change in the timbre between off -axis and on -axis listening positions for frequency components above 1 kHz. The edge -diffraction components are slightly displaced, due to the change in geometry, but remain at a reasonably low level at 4.3 and 4.8 milliseconds. In spite of the difference in appearance between the on -axis and off -axis energy -time curves, 95 percent of the sound energy from both positions arrives within 0.45 milliseconds of the first sound arrival. These measurements lead this reviewer to recommend rotating the T-400 toward the listening position to improve its transient reproduction. Listening Test The T-400 speakers were initially placed against a flat wall, recommended by Panasonic. The listening geometry chosen for stereo material consisted of an equilateral triangle with the spacing between speakers approximately 3 meters. In this position there was a distinct midbass peak that caused an unnatural emphasis of male vocals and midbass instruments. This was partially cured by pulling the speakers away from the walls about a half meter, but the bass was still considered too hot. The T-400 is a good reproducer of organ music, but has a distinct tendency to make you aware of any rumble or hum in your system. A small bass cut with the pre amp equalizer finally achieved what was considered the best balance. At high sound levels the bass has a tendency to become less distinct in percussive articulation. After considerable adjusting and listening, final adjustment positions were the midrange equalizer switch in the high position and the tweeter switch in the low position. The extreme high frequencies were down in level when this was done, but a more uniform balance resulted without top end spit or annoying levels of audible record scratch. The T-400 delivers good kick drum sound and can handle a lot of horn and brass peak power without caving in. Solo vocals are well placed and clear in the stereo image. Choral groups seemed spatially smeared and indistinct. Despite this apparent contradiction in reproduction of the human voice, this impression was noted in several types of selections. The listening position for good stereo imagery is a bit critical for wide range material when the speakers are placed flat against the back wall. Rotating the speakers toward the listening position definitely helped the stereo imagery at the preferred listening position, but restricted the listening area to a best -seat -in -the -house situation. If one listens alone, recommend pulling the speakers away from the wall and rotating them inward toward your seating location; otherwise, pull them away from the wall but do not rotate them. The T-400, though not intended as state of the art, does deliver accurate and high quality sound. It demands a good amplifier and clean program material and is well suited for listening areas that are bright in their acoustic properties. Richard C. Heyser as I W CC 30 40 30 35 TIME - 45 45 5.0 MILLISECONDS Fig. 12-One-meter energy -time response measured 30 degrees off axis. Check No. 91 on Reader Service Card AUDIO DECEMBER, 62 www.americanradiohistory.com AmericanRadioHistory.Com 1975 This Christmas give a sound gift GIVE AUDIO MAGAZINE Looking for the perfect gift for the hi-fi/stereo enthusiast? Maybe it's your son, sister, father, friend or even a business associate. Give Audio Magazine, the gift that will be the gift remembered twelve times during the year that comes every month. ... A SUBSCRIPT ION TO AITI)IO The first gift subscription is only $7.00 and each additional gift subscription is at the money saving rate of $4.68. and save when you buy Give the gift that's special two or more subscriptions. ... WE'LL SENT) AN ENGRAVED GIFT CAlfi. Each person will receive a beautifully engraved gift card telling the gift is from you. Take advantage of this special holiday offer. Mail the order form today. By the way, why not include yourself and extend your own subscription. SPECIAL, CHRISTMAS SUBSCRIPTION ORDER First Subscription $7.00, 1 Engraved Gift Card should read from year Name Bill Me Address City _dip State D Payment enclosed Charge my credit card No Expires American Express Master Charge Additional Subscription $4.68, 1 year (Bank No Name My Name Address City ) Zip State Address State City Additional Subscription $4.68, 1 year Zip Signature Name Address City State lip Rush this order to Audio Gift Manager, 401 N. Broad Street, Philadelphia, Pa. 19108 www.americanradiohistory.com AmericanRadioHistory.Com Yamaha Model CT -7000 Stereo FM Tuner a massive tuning knob coupled to just about the smoothest acting flywheel arrangement we've ever spun across the 20 MHz's of the FM band. Ah, but when you tap the door base lightly to open it (it swings downwards), what additional wonders are disclosed! There's a built-in headphone jack powered by its own amplifier and a level control for that output, as well as one for the variable -level output jacks at the rear. There's a Muting on -off switch placed adjacent to a control which varies muting threshold, an I.F. Mode switch which varies the i.f. bandwidth (about which we'll have much more to say shortly), a button which selects mode of operation of the dual purpose signal -strength meter, an Auto -Blend switch which, when activated, introduces two degrees of high -blend when listening to weak -signal stereo, depending upon actual signal strength. Also hidden behind the hinged door are a mono/stereo Mode switch and a pushbutton which turns the dial Illumination on and off. The rear panel, pictured in Fig. 1, contains antenna input terminals for 300 -ohm connection and two types of connection facilities for 75 -ohm transmission lines-one a coaxial connector, the other a combination of cable clamp (to retain the cable by gripping the outer shielded conductor) and screw terminal for the inner conductor. There are two pairs of output jacks, one for the fixed level outputs, the other for the variable level outputs controlled from the front panel. A pair of jacks designed for connection to an external oscilloscope comes next, followed by an i.f. output jack (which might perhaps been labelled more clearly as a detector or 4-channel output jack which is what it is). A chassis ground terminal, fuseholder and unswitched convenience a.c. outlet complete the rear panel layout. and MIN FM n n n n n MANUFACTURER'S SPECIFICATIONS IHF Sensitivity: Normal, 2.0 µV; Wide, 2.5 pV. Selectivity: Normal, 85 dB; Wide, 18 dB. S/N: Mono, 78 dB; Stereo, 75 dB. Capture Ratio: Normal, 0.7 dB; Wide, 0.6 dB. THD: Mono-normal, 0.06%; Mono -wide, 0.04%; Stereo -normal, 0.06%; Stereo-wide, 0.04% at 400 Hz. THD (from 50 Hz to 10 kHz): Mono -normal, 0.2%; Mono -wide, 0.08%; Stereo -normal, 0.3%; Stereo -wide, 0.15%. Image, I.F. and Spurious Rejection: Over 120 dB. AM Suppression: Over 60 dB. Separation: 400 Hz, normal or wide, 50 dB; from 50 Hz to 10 kHz; normal, 35 dB; Wide, 40 dB. Frequency Response: 30 -15000 Hz ±0.3 dB. Sub-carrier Suppression: 70 dB. Muting Override Signal Level: From 3 to 30 µV. Stereo Threshold: From 3 to 30 µV. OutputLevel: 775 mV fixed; 2mV to 70mV variable. GENERAL SPECIFICATIONS Power Consumption: 23 watts, 13 watts with illumination off. Dimensions: 17 Y. in. W x 5 e14 in. H x 121 in. D. Weight: 28.6 lbs. Price: $1200.00 The first thing that must be said about this magnificent FM tuner from Yamaha is that it succeeded in giving the test equipment in our laboratory a bad inferiority complex. Frankly, we thought we had upgraded our measurement equipment so that it was a couple of orders of magnitude better than anything we would be called upon to test. Yet the Yamaha CT -7000 specs are, in the main, better than we are able to measure. And rather than repeat that statement with each reported measurement that follows, we thought we'd better get that out of the way right at the beginning. We shall report our measurements as we read them, with the understanding that readers (and the people at Yamaha) will sympathize with our limitations. As for the operating features, circuit highlights, and appearance of this tuner, those we can describe quite accurately, and the photo of the front panel helps. Many of the goodies are hidden under that sleek hinged door which runs across most of the lower portion of the front panel. But with it closed, all one sees when looking at the brushed silver panel of the Yamaha CT -7000 is a long, linear dial scale, calibrated at every MHz and augmented by a 100 point logging scale for easy station reference. Two small "windows" at the right frame the center-of -channel tuning meter and the signal -strength meter which also doubles as a multipath indicating meter. There's a lever -toggle power on -off switch Circuit Details Details of the circuitry contained in the Yamaha CT -7000 would take longer to enumerate than the entire length of this report. We shall try to describe a few of the more important and innovative ones. (Refer to Fig. 2, an internal view.) Three dual -gate MOS FETs are used in the frontend, which contains two full stages of r.f. amplification and employs what Yamaha claims is the world's first seven -gang tuning capacitor. A seven -stage differential amplifier is used in the i.f. section together with ceramic and LC filter blocks. There are actually two separate i.f. stages; "normal" mode is for best selectivity in "crowded" signal areas, while "wide band" works best where station crowding is not a problem aw T n I111 o o o ® e e 1-Rear panel. Fig. o o m Fig. ,.rS,;kl,4 E itr1 ,en rdNsN e ;t+4 r .' r 4 fpYyle,rÓhai t r: mMedZhen;, ;wàiát 2-Interior view. AUDIO 64 www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 Reintroducing A World Standard... CBS Laboratories' STR Professional Test Records For over ten years, the original series of these high -precision test records set a standard for the audio industry. Now the new series sets an even higher standard. It's been revised, recut and expanded. The new series consists of eight records for professionals and one for non-professional audiophiles. Each record contains a complete series of easy -to -use tests to help you rapidly and accurately evaluate components and systems. Even one of these records can eliminate the need for costly, additional equipment. Each will find productive use and save you hours in the laboratory, on the production line and in field testing. Take a look at what this essential testing series contains: SEVEN STEPS TO BETTER LISTENING -For only $6.98, you can improve your system with CBS Laboratories' "Seven Steps to Better to tune your system to Listening." This high -precision test record enables you to make sure that your equipment functions properly your ears and your room acoustics. Included is a detailed 16 -page booklet by Audio's Edward Tatnall Canby explaining how to use the record to improve the performance of your system. With the record you can perform the following "ears alone" tests: left -right identification, phasing, loudspeaker balance, tone control setting, alternate phasing, buzz and rattle elimination, lateral tracking, and ... vertical tracking. MICROSECOND FREQUENCY RESPONSE TEST RECORD STR 170 Provides pickup designers and recording studios with a high-level, easily -equalized signal for frequency response and channel separation measurements. The STR 170 employs a 318 microsecond characteristic corresponding to the "test" or "flat" mode common to most disc recording equipment. Constant amplitude recording is employed In the region below 500 Hz with constant velocity recording in the region above. The transition is smooth, in contrast with the STR 100 which employs a sharp breakpoint at 500 Hz. The record is suitable for use with a graphic level recorderp to provide permanent, visible records for precise evaluation. *STEREOPHONIC FREQUENCY TEST RECORD STR 100 Designed for the evaluation of pickups and systems. Provides a constant amplitude characteristic below 500 Hz and a constant velocity characteristic above 500 Hz. Tests include: Sweep Frequency-with the sweep rate synchronized for use with a graphic level recorder; Spot Frequency-with voice announcements; Channel Separation; Wavelength Loss and Stylus Wear-to pinpoint oversize or worn-out styli, and excessive pickup tracking force; Compliance; Phasing; Vertical and Lateral Tracking: Tone Arm Resonance-to check system performance at low and subaudible frequencies and thus reveal undamped resonance which may cause equipment overloading. *318 *SQUARE WAVE, TRACKING AND INTERMODULATION TEST RECORD *WIDE STR 112 Enables detailed study of tracking capabilities of stereophonic phonograph pickups. The square wave modulation allows a rapid appraisal of stylus -tip mass, damping, and tracking. Low frequency compliance and tracking are determined by means of 300 -Hz bands of progressively increasing amplitude. Intermodulation distortion measurements are made possible by graduated 200 -Hz intermodulation test bands. The Str 112 has been cut with vertical angle approximating 15°, which is representative of current recording practice. TEST RECORD * BROADCAST needs of broadcast engineers, STR 151 Developed especially to meet the audiophiles, and other professionals seeking a convenient signal source for the testing and adjustment of all audio equipment. Tests Include: phonograph pickup response and separation, speed accuracy at 33 1/3 and 45rpm, wow and flutter, rumble and hum detection, ballistic test of V.U. meters and many others." * RIAA FREQUENCY RESPONSE TEST RECORD STR 130 Provides RIAA frequency characteristics for the calibration of professional recording equipment and for testing the response of professional and consumer record reproduction equipment. This record is suitable for use with a graphic level recorder to provide permanent, visible records for precise evaluation. Spot frequency bands for use without automatic equipment are included. * RANGE PICKUP RESPONSE TEST RECORD STR 120 Makes possible the measurement of pickup response at frequencies far beyond the audible range, where elusive distortion elements can cause audible distortion. The low -frequency range Includes glide -tones at twice normal level for the detection and elimination of arm resonance, loudspeaker cone and cabinet rattles. Other tests include: silent grooves for measuring rumble and surface noise characteristics; and standard level bands at O dB for overall system S/N measurements. This record is suitable for use with a graphic level recorder to provide permanent, visible records for precise evaluation. QUADRAPHONIC TEST RECORD SOT 1100 Designed for calibration verification, and adjustment of SQ'" decoding equipment. The record provides test bands for pickup measurements, for adjustment of decoder electronics and for channel identification and balance. Each band is described in terms of recorded characteristics and its intended use. PINK NOISE ACOUSTICAL TEST RECORD STR 140 Designed for acoustical testing of systems and loudspeakers and for psychoacoustic tests on reproduction equipment. With the STR 140 It becomes possible to test loudspeakers in the room in which they will be used. Spot frequency tones with voice announcements facilitate the testing procedure. Continuous glide -tones in 1/3 -octave bands cover the frequency range from 30 to 15,000 Hz and are synchronized with a graphic level recorder. *RIAA The original series has been unavailable for many years. Quantities of the new and improved series are also limited. So make sure you have perfect copies on hand for years to come by ordering duplicates. Fill out and mail so is a TrademarkofCBSlnc. the coupon now for immediate action. Only a limited quantity are available. Be sure to order enough for many years of use. SEND TO: AUDIO TEST RECORDS 401 N. Broad Street Philadelphia, Pa. 19108 Send me the following test records: Seven Steps to Better Listening (STR 101) $6.98 each. Quantity E Stereophonic Frequency (STR 100) $10.00 each. Quantity Square Wave, Tracking and Intermodulation (STR 112) $15.00 each. Quantity Wide Range Pickup Response (STR 120) $15.00 each. Quantity RIAA Frequency Response (STR 130) $15.00 each. Quantity RIAA Pink Noise Acoustical (STR 140) $15.00 each. Quantity E Broadcast test (STR 151) $15.00 each. Quantity H 318 Microsecond Frequency Response (STR 170) $15.00 each. Quantity Quadraphonic Test (SQT 1100) $15.00 each. Quantity Amount Enclosed $ (Payment must accompany order) Name Address City State www.americanradiohistory.com AmericanRadioHistory.Com lip and you want the ultimate in phase linearity, high -frequency stereo separation, and lowest possible distortion. A linear -phase wideband discriminator circuit serves as an FM detector and is, according to the maker, individually adjusted for minimum phase distortion. A dual -stage, constant current circuit drives the detector for increased stability. The MPX decoder section employs a phase -lock loop circuit built up from discrete components (rather than from one of the available "packaged" IC PLLs now available). Negative feedback, unique to Yamaha, is used to reduce inter modulation distortion. As for the PLL circuitry, it is of the type that requires no tuned inductance circuits. Active lowpass filters are used to provide the necessary de -emphasis characteristic, and the outputs of these filters are direct coupled in a three -stage amplifying system, which includes a buffer amplifier. A separate three -stage direct -coupled audio amplifier is used to drive the headphone jack. Each circuit board used in the construction of the Yamaha CT -7000 is individually shielded in its own stainless steel cover. While we don't normally "count transistors" in evaluating the quality of a product, it may be of some interest to readers to know that this tuner contains 108 transistors, 12 FETs, 33 diodes, nine zener diodes, and seven IC circuits! Laboratory Measurements Again, with apologies for our test equipment, we measured an IHF sensitivity of 1.9 µV in the "normal" i.f. position and 2.4 µV in the "wide" position. Some 50 dB of quieting was attained at 2.8 µV and 3.4 µV for these two operating modes respectively. Figures 3 and 4 show our measured S/N results of 78 dB and 69 dB for mono and stereo in the "narrow" or "normal" position and 75 dB and 68 dB for the same measurements made in the "wide" setting. We suspect that our generator's limit in mono is therefore mono 78 dB in o mv I F 2 5 IIIÌÌv111111IiIIIIII111111i11111 "aIIIIIIIIIIIIIIIIIIIm11111 --ví ....lIIIimIIIII 1IIIIIIInsIII111111111 THD- 0.065% 11111 30 muIIIIII\IIIII IoIIII -0.077x 3L1111 3IIIIIII1M\11IL ;11131 40 IIIIIII111131/111 IN:9IIIIII1IIIIIIIIIIIIII 10 20 30 10 ap MONO I 3 STEREO THD 50 60 IIIIIIIli!i1 !1111IÌ2111111.1 !l,1111I. ieiliiiill'ii:=¡i:! ./._1FIE:? .3 a J -70 M31111111311111 W ir -80 31131111111311111132;!!!!!!!!!! !!"e!Li111 .31111I1I11111III1111111 MONO S/N =78dB (See Text) 111I .ii1111111iiM11111111i 0.1 1 0 INPUT 10 STEREO S/N. 69dB 100 (See Text) I º = z O 1- (.0 ii11 IK IOK - MICROVOLTS ACROSS 300 OHMS Fig. 3-FM quieting and distortion characteristics, i.f. position. "Normal" and somewhere around 70 dB in stereo, which accounts for our inability to measure claimed specs. Note too that our THD measurements at mid -frequencies (1 kHz) for both the "normal" and "wide" settings were the same, indicating clearly that we were limited by the built-in distortion of our signal generating equipment. We are therefore in no position to dispute Yamaha's claim of 0.04% in the wide position for both mono and stereo. It's very likely true! We had previously suspected that the stereo separation capability of our stereo FM generator was about 50 dB, since that's the most we ever measured for any tuner or receiver we ever tested. Much to our surprise, we obtained a reading of 53 dB for mid -frequency separation when operating the CT-7000 in the narrow position, as plotted in Fig. 5. Interestingly, in the "wide" operating mode, although mid -band separation was slightly less, high frequency separation was clearly better, remaining above 40 dB all the way out to 15 kHz. These two plots clearly prove the importance of wide bandwidth for good high -frequency stereo separation, as well as the need for excellent phase linearity throughout the i.f. and detection system. Yamaha obviously has a good measure of both. Even within the limitations of the generator, the distortion curves shown at the bottom of Fig. 6 clearly show that increased bandwidth leads to lower high -frequency distortion in stereo. Note that when this setting was used, THD at 10 kHz in stereo was less than 0.3%-the lowest we have ever encountered. No low-pass filters were used in making this or any other measurements. There was just no evidence of the usual "beats" with the 19 -kHz carrier we find with so many other FM tuners. As for spurious, image, and i.f. rejection, our instrumentation permits us to read up to 100 dB for these specs. That's what we read with the Yamaha under test. The manufacturer claims better than 120 dB for each. What more can we say? Measuring capture ratio below 1.0 dB is tricky at best, but we managed to confirm at least one of Yamaha's claims for this important spec: 0.7 dB in the normal setting with a 100 µV input. Fantastic! Muting level was found to be adjustable in our sample over the signal strength range from 4µV, while stereo threshold was factory set at about 7.0 µV, a suitable point for this tuner. Transition from mono to stereo is noiseless and absolutely positive. At signals below 100 µV, blending of high frequencies as well as upper mid -frequencies takes place automatically, reducing separation substantially above 1 kHz, but reducing noise to listenable levels. Between 100 µV and 1 mV signal strengths, the auto -blend feature, if activated, blends highs to a lesser. degree, retaining adequate separation while accomplishing noise reduction which makes medium -strength signals received from stereo broadcasters quite good, in terms of background noise. 0 á j 0 H - 10 -20 I- "L" ONLY INPUT "L" OUTPUT 0 -10 MONO - 30 THD=0.065,6 (See Tee )7 STEREO THD =0.077% See 40 --- 20 3.0 30 50 40 L 60 50 70 80 MONO I0 INPUT 10 100 INPUT,"R" OUTPUT 881 8I S/N' 75dB STEREO S/N 0.1 NARROW .F. SETTING WIDE I.F SETTING = STEREO 68dB'- IK 1.0 0.5 ONO 10K 10 - MICROVOLTS ACROSS 300 OHMS 100 1K IOK 20K o FREQUENCY- Hz Fig. 4-FM quieting and distortion characteristics, i.f. position. "Wide" Fig. 5-Separation and distortion versus frequency. 66 AUDIO DECEMBER, www.americanradiohistory.com AmericanRadioHistory.Com 1975 NOW... anAUDlO exclusive: This timely SOUND ADVICE suggestion: A Comprehensive Guide to the Music/Record Business .. 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Law Firm of Roemer & Nadler Alvin Teller V.P. Merchandising Marketing, Bob Cato Kip Cohen Al Coury r- 10 DAYS FREE APPROVAL-MAIL TODAY Book and Learning Systems Division NORTH AMERICAN PUBLISHING COMPANY 401 N. Broad Street, Philadelphia, Pa. 19108 Send me the complete "MUSIC INDUSTRY CASSETTE LIBRARY." If decide to keep this after 10 days examination will remit the purchase price plus postage and handling, or return it for cancellation of all I I charges. Name(please print) Signature Firm or Inst. Home Address Columbia Records Peter Thall Ron Weisner Law Firm of Casper & Thall, P.C. V.P., Artist Relations, Buddah Records ... and many others City,State,Zip money-back SAVE MONEY. My payment is enclosed. Publisher pays all postage and handling. Same return privilege. www.americanradiohistory.com AmericanRadioHistory.Com J Listening and Use Tests We were in for a few more surprises when we got down to our listening tests and evaluations. It was then that we first began to appreciate what Yamaha calls its "auto -touch tuning" system. The large tuning knob is actually part of a capacitance switch which is activated by the user when he touches the knob. While tuning to a station, the built-in a.f.c. circuitry is turned off to enable the user to zero in precisely on the desired station signal. While this tuning is in process, the tuning indicator lamp is extinguished. As a station signal is approached, it glows softly and, when tuning has been completed and the user lets go of the tuning knob, the a.f.c. circuit comes back on and the tuning indicator is illuminated to full brightness. Normally, we have frowned upon a.f.c. circuits in general as it was our feeling that they usually contribute to distortion and non-linearities in a tuner circuit, and that given today's heat -free solid-state stable circuitry, there is no need for a.f.c. as a drift -prevention crutch. Well, this a.f.c. circuitry contributes absolutely no added distortion to the audio output of the Yamaha CT -7000. In fact, all our measurements in the lab were made with the a.f.c. active since we obviously didn't keep our fingers on the tuning knob while making the measurements. When we became aware of the a.f.c. feature and the way it works, we decided to check some of our measurements to see if we could fine-tune the tuner (with hands on tuning knob to deactivate the a.f.c.) for lower distortion than we had previously observed. If any improvement occurred under these conditions, it was too low for us to observe, since we were already below 0.065% in our previous mono THD readings. Nor could we detect even the slightest shift or change of appearance of the output waveform as observed on our monitoring oscilloscopes as a.f.c. was activated and deactivated. The only time the a.f.c. did anything was when we deliberately detuned the signal. Under those conditions, the a.f.c. was strong enough (when reactivated automatically) to pull the tuning close enough to optimum so that distortion was once again below 0.1%. Here is an Koss HV/1A Headphone a.f.c. circuit that doesn't "get in the way" of performance and can be of genuine assistance to the "sloppy" knob twirler who doesn't have the patience to tune as carefully as he or she should! (Editor's Note: Yamaha says they designed the a.f.c. circuitry in their tuner sections as a final tuning compensator, to minimize distortion and increase separation.) It goes without saying that the signals received were limited in quality entirely by the broadcast practices of the stations we received. Which, of course, brings us to the ultimate question. Should one spend $1200.00 on what is probably the best performing tuner presently available, when most stations are becoming worse and worse insofar as the quality of their broadcast signals are concerned? That depends largely upon where you are located and whether or not you have stations in your area that are careful about the kinds of signals they transmit. Is this the "best" tuner we have ever measured? Well, the previously tested Sequerra Model One does as well (we can't say "better" since in both cases our test equipment was not as good as the product demanded), but it costs more than twice as much as the Yamaha. Of course, the Sequerra has all kinds of nice things like digital frequency readout and panoramic oscilloscope displays, use of a scope instead of meters for tuning and signal analysis, and the like. There would therefore seem to be two choices for the absolute perfectionist who seeks the best in FM tuners. If you are fascinated by digital readout, scopes and the like and seek absolutely tops in specifications and performance, take home a Sequerra Model One. If you are strictly a purist, and want a super FM tuner, that's equally first-rate in its specifications and measured performance, that's flawlessly designed, simple to operate, and offers that important wide -band mode (we were able to take advantage of it even in the crowded New York metropolitan area down at the bottom of the dial), you're not likely to find a better performer than the Yamaha CT -7000. Leonard Feldman Check No. 92 on Reader Service Card 0.9 V rms, sine wave, at 1 kHz; 0.5 V rms pink noise. THD: Less than 0.5% at 1 kHz, 100 dB SPL. SPL at 1% THD, 1 kHz: 108 dB. Power Handling Capability: 5 V continuous. Cord: 3 -conductor, coiled, 3 meters (10 ft.) extended. Earcushions: MANUFACTURER'S SPECIFICATIONS Elements: 50 -mm dia. (2 in.) Decilite TM dynamic, velocity operated. Source Impedance: 157 ohms at 1 kHz, designed to operate with source impedances of 3.2 to 600 ohms. Frequency Response: 15 to 20,000 Hz. Sensitivity for 100 dB SPL: Soft acoustical sponge. Headband: Extendable, with self adjusting, pivoting yokes and soft, padded vinyl cover. Weight: 285 grams (10 oz.) less cord. Price: $49.95. The Manufacturer's Specifications section above just about tells the entire story, since there is very little more that can be said. However, some additional details may be interesting to the reader. For example, the foam pads are doughnut -shaped, 23/4 in. outside diameter with the "hole" opening 1-5/16 in. diameter, and the depth is 3/4 in. The color is dark drown, matching the brown plastic cups which have a shiny chromed trim ring. The cups are vented both in back and around the sides, which accounts for the low isolation from external sounds. The cups themselves are 3 inches in diameter and are held by a double swivel, permitting full adjustment to the wearer's ears. The extendable portion of the band has detents to ensure that it remains in the selected position. The band itself is a sturdy steel strip, vinyl covered, with the detent mechanism encased in molded plastic terminations of the band. The cord is dark brown in color, miniature in dimension, and is coiled in a very compact form, with the three leads terminating in a detachable plug, rather than a molded one which is difficult to replace if ever one wants to change to some other form of plug. The d.c. resistance of each phone was measured at 148 ohms in the maximum -volume position and 869 ohms in the minimum -volume position, indicating that the level control is a series resistance, which would be a distinct advantage if the 68 AUDIO www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 duced "flat" with networks using R and C elements, as is the case with Justi-Meter III. The record is reproduced, and the output fed to an amplifier with the signal terminated by the amplifier's normal load resistance. The signal is adjusted to 3.0 volts, and the headphone driven from this 3 -volt signal through 100 ohms-about normal for receiver headphone 5dB jacks. SPL=91dB 20 100 I K FREQUENCY Fig. 1-Frequency response of - H- Koss 10K 20K HV/1A stereophones. phones were to be used on 600 -ohm circuits. The impedance of the single phone was measured at 240 ohms. Weight is specified as 10 oz. for the phones, less cord, though the cord and plug add only another 3 oz. to the total. Measurement Method Determining the performance characteristics of headis a fairly complicated project. The phones must be coupled to a microphone by means of an artificial ear of specific characteristics-and here there is a difference of opinion. In general, the cavity between the microphone diaphragm and the headphone diaphragm is specified as 6 cu. cm for headphones and 2.5 cu. cm for hearing -aid phones phones. For some years, this observer has used a shop -built artificial ear which gets modified occasionally in striving for improved performance. The "ear" consists of a maple block 5 Y2 inch in diameter and 6 1 inches long-about the dimensions of the average head as far as spacing goes. Through the center is a 3/4 -in. hole to accommodate an AKG C -451E condenser microphone, and on the front is a B & K metal adapter. The microphone is inserted just far enough to provide the 6 -cu. cm cavity. The microphone-suitably modified for single -ended use rather than for the phantom powering normally used-has its output fed into the proper receptacle on a graphic recorder, the Justi-Meter III. For a frequency run, the source is the B & K QR-2009 test record, which has a sweep from 20 to 20,000 Hz, and it's equalized in such a manner that it can be repro - Frequency runs are made for both phones, and a second measurement is made by reproducing a 400 -Hz square wave through a loudspeaker and with the headphones off the "ear," the output of the microphone is measured. The phones are then placed on the ear, and the output again measured. This gives the isolation, in dB, with the phones on the ear, as compared with the signal without the phones. There are many uses where a high degree of isolation is desired, as where one is recording in the presence of a live source, and airborne sound from the source should be reduced as much as possible in order to hear the actual sound that is being recorded. Performance Figure 1 shows the frequency characteristic of the HV/1A phones, averaged between the two phones of the pair. While that may seem a little unscientific, it is actually almost the way we hear the phones. And besides, the two curves were never more than 3 dB apart over the entire range from 20 to 20,000 Hz-a remarkable feat. Furthermore, these phones offer the best-thus, flattest-response of any that we have measured with the exception of the Koss ESP -9. Sound pressure level from these phones measured 91 dB with the 3 -volt signal applied through 100 ohms, a value which is lower than the loudest ones tested, but still within the ball park. The HV/1A phones are still 3 dB louder than the Koss ESP -9, and to the average user, adequately loud for any normal purpose, though perhaps not loud enough for the rock buff. In any case, they were comfortable to wear for periods up to one hour, at least, and were not tested for more than that at one sitting. Because of the openings in the cup and the softness of the foam pads, isolation from outside sounds was less than 2 dB, so the phones would not be suitable for recording in the vicinity of the live source, but for simply listening to music, C. G. McProud they are excellent. Check No. 93 on Reader Service Card Crown VFX 2 Electronic Filter -Crossover rated output. Filters: Separate 18 -dB Butterworth high and low pass with adjustable corner frequencies. Dimensions: 19 in. rack mount with W.E. hole spacing, 3 Y2 in. H, 5 Wi in. D. Weight: 6 lbs. Price: $299.00 The Crown Model VFX2 is a dual -channel filter/crossover unit designed to provide continuously variable filters to perform either high-pass, low-pass, or bandpass functions in a professional, commercial or home high fidelity system. The unit is ruggedly constructed and fits the standard 19 in. rack mount, occupying only 3 Y2 in. of vertical rack space and 5 inches in depth. The front panel has four sets of range/vernier knobs for the high- and low-pass frequency setting of the filters in the two audio channels. A shadow mask pushbutton switch controls the power. The rear panel controls are a screwdriver adjustable level (attenuator) control and a mode switch for selecting either the crossover (low pass) or filter (bandpass) outputs for each audio channel. Rear -panel connectors include a variable -gain bridging input for each channel in ad - ' MANUFACTURER'S SPECIFICATIONS Frequency Response: 18 Hz to 38 kHz ±0.5 dB with 600 ohm to¡d. Output: 10 V maximum, 2.5 V rated with 600 ohm load. Gain: 0 to 15.5 dB. Hum and Noise: 100 dB below rated output, 20 Hz to 20 kHz. IM Distortion: Less than 0.01% at AUDIO DECEMBER, 69 1975 www.americanradiohistory.com AmericanRadioHistory.Com dition to the unity -gain unbalanced input. Output connectors (both high and low pass) are provided for inverted and noninverted (normal) modes. For greater reliability, the VFX2 uses 1/4 -in. phone jacks; input is by 3 -conductor jacks balanced/unbalanced or 2-conductor jacks unbalanced unity gain; output is by 2-conductor jacks. To prevent the accidental moving of the range/vernier settings, the VFX2 has a smoked plastic cover that can be attached over the front of the unit. The VFX2 filter set is quite useful for reprocessing or playing all types of records, particularly the early 78 -rpm acoustics and electrics as well as the more recent monophonic 78s and LPs, the current stereo and matrix recordings. Other equally important uses include equalizing deficient program material in a manner not possible with the usual tonè controls, constructing one-third octave or other narrow band pink -noise sources for use in acoustical measurements, etc. Of particular interest to the professional and the audiophile is the use of the VFX2 as a high -quality dual -channel crossover with 18 dB/octave slopes and continuously variable crossover frequencies. Currently, there is renewed interest in electronic crossovers for use in bi- and tri -amplified speaker systems, with great interest in achieving true high fidelity bass performance by utilizing speakers specifically designed for low bass reproduction. The VFX2 utilizes five RC4558 dual operational amplifiers _ ó 0-0--.- O ,_ . CO '19;-.4 Fig. 1-Rear Fig. 2-Internal view. ,. i panel. design approach are very high input impedances, low output impedances, and low sensitivities to drift arising from temperature changes and circuit aging. The liberal use of operational amplifiers in the VFX2 is apparent throughout the. unit. There are buffer amplifiers at the inputs to assure very high (1 megohm) input impedances which permits use of the crossover with long cables and any type of preamplifier. Use of high supply voltages for the op -amps, e.g., ± 15 volts, assures that the crossover can handle up to 10 volts without overloading. At unity gain, this type of output is far greater than is required by any power amplifier. The liberal use of op -amps is also apparent in the availability of inverting outputs. Each of these inverting outputs requires one op -amp so that four of these op -amps are used to supply the four inverted outputs. The inverting outputs, although not essential, are a very useful addition because phasing of the loudspeakers can be made at the crossover rather than changing connections at the speaker or power amplifier. Phasing becomes particularly important when the crossover is set at very low frequencies (e.g., 100 Hz) such as when used with a high quality extended -bass system. An out -of -phase condition between the low -frequency speaker and the rest of the system would appear as an attenuation in the upper bass region and would definitely be audible. By merely changing the outputs from Normal to Inverted for one of the sections (high pass or low pass), the listener can quickly determine which jack gives the correct phasing. The filter characteristic is a third -order Butterworth, which has a maximally flat response in the pass band of the filter to a time dependent signal such as is encountered with musical material. The phase shifts for this type of filter are, however, not linear with frequency. A linear response would be an ideal case since this would lead to a constant group delay at all frequencies and, consequently, the time dependent signal would not be distorted. However, human hearing is relatively less sensitive to distortions of this kind than it is to amplitude variations with frequency, e.g., ripple in the pass band. Measurements of harmonic distortion products using a wave analyzer with an 80-dB range showed that second harmonic distortion was always less than 0.1% at input voltages less than 9 volts and at frequencies below 10 kHz. Third harmonic and all higher order distortion components were nearly unmeasureable, i.e., less than 0.01%. The second harmonic distortion reflected the internal residual distortion of the oscillator and not of the VFX2. The frequency response measured was the same as given in the VFX2 specifications. i 5dB in each channel, in effect, 20 op -amps equivalent to 402 transistors, 44 diodes, and 2 zeners. The circuit appears to be a variant of a non -inverting voltage -controlled voltage source (VCVS) design, and consists of a 6 dB/octave stage cascaded with a second 12 dB/octave section. The latter is implemented with two operational amplifiers. Results of this 20 100 10K IK FREQUENCY -Hz Fig. 3-Response with crossover frequency of 100 Hz. 70 AUDIO www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 The slopes of the filters were within 0.5 dB down to -60 dB relative to the bandpass output. The corner frequencies as indicated on the front panel are reasonably accurate. However, for exact frequency settings, use a simple a.c. voltmeter, an audio oscillator and, if available, a frequency counter. Figure 3 shows the response curve for the VFX2 when set for a crossover frequency of exactly 100 Hz. In using the Crown VFX2 as a crossover in our system, we noted two deficiencies. The first is a lack of level controls on 5dB e 20 IK 100 FREQUENCY 10K -Hz Fig. 4-Bandpass setting with cutoff frequencies of 160 and 3000 Hz, 18 dB/octave slope rate. 5dB } Í 20 100 1K FREQUENCY - 10K Hz Fig. 5-Bandpass setting with cutoff frequencies of 160 and 3000 Hz, 36 dB/octave slope rate. 5dB 20 100 10K IK FREQUENCY 20K - Hz Fig. 6-Setting for noisy modern discs, high-pass filter at 20 Hz or off, low-pass at 10 kHz with 18 dB/octave slope rate. AUDIO the high- and low-pass sections, which means that power amplifiers used with the VFX2 should have a volume control to compensate for varying power amplifier sensitivities and loudspeaker efficiencies. The second deficiency is the omission of a summed left -plus -right output for the low-pass filter. Experience shows that for reproduction of low bass, a single monophonic bass speaker (woofer) is adequate in small rooms where the left- and right -channel speakers are not widely spaced, particularly since bass frequencies below about 100 Hz are not directional. A crossover such as the VFX2 cannot be used in this monophonic mode, but must be used with two subwoofers. However, a suitable op -amp mixer is very easy to add to the VFX2 because of its op -amp design, thus permitting the use of one subwoofer in the common mode. As mentioned earlier, the VFX2 is very useful as an 18 dB/octave filter for record collectors, particularly collectors of early acoustic and electrical 78 -rpm shellac records. The unit is inserted in the Tape In and Out circuits or between the preamplifier and amplifier when they are separate units. Figure 4 is a response curve for the playback of early acoustic 78 -rpm records. The high-pass filter of the VFX2 is set at 160 Hz and the low pass filter at 3000 Hz. In practice, the low-pass filter (cutoff frequency) is usually adjusted for each recording as it is being played until the noise elements are removed or diminished appreciably. In Figure 4 the cutoff frequencies are at 160 and 3000 Hz with an attenuation rate of 18 dB/octave, while Figure 5 shows the same response, but at 36 dB/octave attenuation. Note that with such a steep attenuation, the cutoff point has shifted to about 2800 Hz at the high end. A shift towards a narrower bandpass has also occurred at the low end. In Figure 6 the high-pass filter is set at 20 Hz or turned off and low-pass cutoff frequency is set at 10 kHz, with an attenuation rate of 18 dB/octave. This is a useful setting when playing noisy LPs. As mentioned earlier, in practice the low-pass and high-pass filters are usually adjusted while the record is playing and the bandpass limits set for the least amount of noise. During the past six months, the Crown VFX2, used as a crossover, has performed faultlessly in our music system. The unit is set for a low crossover frequency of exactly 100 Hz and the common mode output is fed to a 60 -watt amplifier having a high damping factor. The output of the amplifier is coupled to our Janis Audio Associates W-1 subwoofer. Use of the VFX2 crossover and the W-1 subwoofer permitted us to hear the bass frequencies below 100 Hz in an extremely clean manner and in toto. In the usual high quality music system, the very low bass frequencies are too often missing since very few speakers can adequately reproduce musical frequencies much below 40 Hz. This is particularly true of the low-bass pedal organ frequencies such as the 23 Hz note recorded on the Advent 5009 record (LemmenVierneDupreWidor) and the 27.5 Hz note on the ARK 10251-S (Organ Music From Westminster). There are many classical recordings in which the nine -foot concert bass drum, generally tuned to 31 Hz, is prominently featured, but the actual fundamental is rarely reproduced. On the Columbia MQ33172 (Carmina Burana), the Angel S-35430 (Pictures at an Exhibition), or the RCA QuadraDisc ARD1-0707 (Citizen Kane), to name a few, there is liberal use of this great drum, and this system reproduces it with awesome power and sonority. In the currently popular music the various bass instruments and, in particular, the ultra -low frequencies produced by synthesizers is superbly reproduced. The Crown VFX2 dual -channel filter/crossover is undoubtedly a very excellent crossover in this application. B. V. Pisha Check No. 94 on Reader Service Card 71 DECEMBER, 1975 www.americanradiohistory.com AmericanRadioHistory.Com Speaker with 8 -in. woofer and 1 1 -in. tweeter is also available at $1,600.00 per pair. A 12 -in. woofer is used with a bass reflex enclosure of the phase inverter type and is intended to carry the spectrum up to 1500 Hz. Frequencies above that are carried by a 2 -in. cone tweeter. Except for an optically opaque grille cloth which covers most of the front surface, the front, top, and sides are finished with dark lacquer so smooth you can see your reflec- Nakamichi Reference Monitor Loudspeaker System tion in it. made through either of the two either side of the enclosure. While this is fine for a studio monitor, it is not the thing for a normal user to wire up and connect to his home system, even though XLR plugs and complete wiring instructions are included. We would like to see this changed to a more conventional connector for domestic use. There is no equalization control provided, and the system comes equalized for flat response. To prove that fact, Nakamichi provides an anechoic frequency response measurement and impedance measurement for each system. When you take delivery of this loudspeaker system, invite a husky neighbor over to help you set it up. At 110 lbs. per speaker and with smooth lacquer sides, this system is quite a handful. Part of the reason for this is that Nakamichi recommends the Reference Monitor be mounted 12 to 15 in. away from a wall and 15 to20 in. off the floor. Four standard cinder blocks are suggested for this purpose under each speaker. The cinder blocks do not come with the unit, so be prepared in the finest spirit of noblesse oblige. This system is very efficient and can provide brisk sound levels with low and medium power amplifiers. No unusual requirements are imposed on the remainder of the audio system with the obvious exception that only the highest quality components should be contemplated with a loudspeaker system of this quality. Nakamichi supplies a short, but very thorough instruction brochure with the Reference Speaker connection is XLR type receptacles provided, one on MANUFACTURER'S SPECIFICATIONS Frequency Response: 40 Hz to 16 kHz ±5 dB, on axis; 40 Hz to 10 kHz ±10 dB, 60° off axis. Power Rating: 60 watts peak, 20 watts intermittent, 3 watts continuous. Nominal Impedance: 8 ohms. Sensitivity: 96 dB SPL for 1 -watt input at one meter on axis. Harmonic Distortion: Less than 7 per cent at 10 -watts input (106 dB SPL at one meter on axis) above 50 Hz. Dimensions: 25 1 W x 345/8 H x 17 1/4 D. Weight: 110 lbs. (50 kg). Price: $2,400.00 per pair. ers, has expanded their product line to include loudspeakers. The loudspeaker introduced under the label Nakamichi Reference Monitor is new in this country, but is a system developed and manufactured by Mitsubishi Electric Corp. and reportedly is used as a studio monitor by the Japan Broadcasting Corporation (NHK) as well as broadcasting stations and recording studios throughout Japan. (Editor's Note: Smaller version of this Nakamichi Reference Monitor Monitor. Technical Measurements The magnitude of the measured impedance is shown in two resonance peaks in the bass frequency region are due to the fact that this system is a vented design. There are some interesting details in the 400 Hz to 4000 Hz region that indicate some interaction of the loudspeaker drivers with their local acoustic environment. The more complete polar impedance plot of Fig. 2 and the expanded scale plot Fig. 1. The + 30 +20 20KHz 20Hz +10 \ 40 0 .-65Hz 10 30 36Hz 20 30 10 x RESISTANCE 20 40 - 50 60 OHMS -20 lo 30 o 20 100 IK FREQUENCY Fig. 1-Impedance. - 10K 20K 40 Hz Fig. 2-Polar impedance plot. AUDIO www.americanradiohistory.com AmericanRadioHistory.Com DECEMBER, 1975 3 show the details of this situation. The two bass resonances occur at 36 Hz and 65 Hz, with values of 42 and 58 ohms respectively. The size of these peaks is not significant to the acoustic response. The expanded plot in Fig. 3 shows the type of load which this speaker imposes on a power amplifier for the frequen- of Fig. 20KHz +10 +5 o 15 10 RESISTANCE - OHMS 5 1.3 KHz 100 Hz 10 Fig. 3-Expanded-scale polar impedance plot. loo 90 80 aJ 70 60 20 100 IK FREQUENCY Fig. - IOK 20K Hz 4-One-meter anechoic amplitude response at one - watt drive. CORRECTED FOR WOOFER ACOUSTIC POSITION III11.J - 90° 1 îuIIlt.I,I"',D 11 TWEETER ACOUSTIC POSITION l -I80° 100 FREQUENCY Fig. 5-One-meter phase response. AUDIO - IOK Hz 20K cy range of 100 Hz to 20 kHz. The nature of this plot indicates that a small amount of acoustic interaction is occur- ring, probably standing wave patterns within the enclosure. The lowest high -frequency capacitive load exists at 1.3 kHz and is 12 ohms at an angle of about 30 degrees lagging, which should offer no problems for any good power amplifier. The lowest impedance measures slightly less than 8 ohms. The one -meter anechoic frequency response is shown in Fig. 4 for its magnitude and Fig. 5 for phase. The sound pressure level in Fig. 4 for a one -watt drive level averages better than 94 dB, which indicates a moderately high efficiency for this system. The low-frequency response falls off rapidly below 50 Hz, a surprisingly high frequency for a professional monitor of this physical size. Since this is a vented system and acoustically unloads so rapidly, it's probably a good idea to use a subsonic cutoff or rumble filter in the preamplifier to prevent subsonic signals from driving the woofer outside its linear range and muddying the response by cross modulation. Such signals could arise from warped records, for example. In a professional recording studio, such program defects do not exist, so a designer need not worry about them. But the signal environment outside the professional studio is quite another story. Interestingly enough, an anechoic response plot on this particular speaker, as it was tested in Japan, was supplied with the unit. Our measurements duplicated those of Mitsubishi perfectly with the exception of a slight difference above 10 kHz which was due to the fact that we test on the geometric center line of the speaker, rather than in front of the tweeter where Mitsubishi's measurements were taken. Moving our microphone to tweeter level verified this, but for standardization we will continue supplying the response taken on the geometric axis. What makes this result significant is not simply the honesty of Mitsubishi, but that their measurement is done in the classic anechoic chamber, while ours is by coherent signal processing, time delay spectrometry, in a quite substantially reverberant room. The overall response is quite uniform on the average, but has localized variations. These are shown by the subsequent energy -time plot to be due to enclosure and grille diffraction. The effect should be an overall balanced sound with some coloration in timbre as one moves his listening position relative to the enclosure. For those technically minded readers, the sound pressure, measured directly in the vent, peaks at 50 Hz, while the near -field woofer cone pressure dips at 43 Hz and has a lower peak at 39 Hz. The phase response Fig. 5 was duplicated for the two acoustic positions of the woofer and the tweeter. The response is in -phase for the woofer and, as is common for passive crossover two-way systems, 180 degrees out of phase for the tweeter. The impulse response will be a preliminary underpressure, followed in a few tenths of a millisecond by a swing to overpressure as the listener's location, as the woofer response arrives slightly after the tweeter response. With the exception of the crossover between drivers, the overall response is principally minimum phase. Of course, the average listener does not live in an an echoic chamber, but uses a room. The three -meter room test of the Nakamichi Reference Monitor is shown in Fig. 6. This test was made, in fact, in the exact position used by this reviewer for the listening test. The speakers were placed on a pedestal formed from four cinder blocks, exactly as recommended by Nakamichi. The speaker was away from the wall and angled toward the listening area. The microphone was placed three meters away from the front of the enclosure and at an ear height of one meter above the floor. 73 DECEMBER, 1975 www.americanradiohistory.com AmericanRadioHistory.Com is shown is the Fourier transform of the first 13 milliseconds of sound due to a perfect impulse. Two measurements are shown, one with the speaker oriented toward the microphone and the other with the speaker angled 30 degrees away in a manner corresponding to a right -channel stereo unit that is pointing to the right of the listener. The plots are displaced 10 dB for clarity. The room response is very good for both positions. The extreme top end dropped inexplicably compared to the an echoic response, though a number of early scatter signals were picked up, and the response is good overall. The fact that the average response is so similar for both angle positions indicates high probability of good stereo imagery. While the off-axis response is some 2 or 3 dB lower than the on -axis, the important thing here is their similarity. The amount of fall off with horizontal off -axis is shown in the polar energy plot of Fig. 7. This is a computation of the total energy in all components from 20 Hz to 20 kHz and is plotted as a function of angle. This plot shows that the Nakamichi Monitor System should be angled toward the listening position for the most uniform energy balance. There is no apparent left -versus -right bias of energy. The vertical energy response is shown in Fig. 8. This loudspeaker launches most of its energy upward. The plot shows that, given a choice, this speaker should be mounted closer to the floor than the ceiling. If the speaker is too close to an acoustically hard ceiling, a distinct coloration will result due to ceiling -scattered sound. Harmonic distortion for the musical tones El or 41 Hz, A2 or 110 Hz, and A4 or 440 Hz is shown in Fig. 9. The woofer showed substantial waveform change in the reproduction of E1 (41 Hz) above the 12 -watt average level and this is signified by the identifying marks on this plot. All other frequencies were easily handled to 100 watts average power. However, with the efficiency of this system, I could only recommend such power levels as a means of breaking leases. With the exception of El (41 Hz), which is really below the acoustic cutoff of this speaker, harmonic distortion is reasonably low. The break in characteristic in the 0.1- to 1 -watt range will be explained later. The frequency response that f f//t41, 10dB ON AXIS 30° RIGHT CH. STEREO POS. 100 1K FREQUENCY Fig. - IOK Hz 6-Three-meter or room response. 20K 0 FRONTAL AXIS Fig. 100 7-Horizontal polar energy response. TOP E2=2nd 10 E1 B2. 3rd = 3rd = 3rd A3 2nd A5 -2nd /f / 0.1 6 Eq A2 E6 Aq A2 A4 z 0.01 100 10 0.1 POWER WATTS . 90 80 I I , 90 1 90 BOTTOM Fig. 8-Vertical polar energy response. 100 100 1 100 SPL E I= 41.2 Hz 1 1 110 SPL A2 = I 110 SPL A4=440 Hz Fig. 9-Harmonic distortion for the tones El or 110 Hz, and A4 or 440 Hz. AUDIO 74 www.americanradiohistory.com AmericanRadioHistory.Com IOHz 1 41 Hz, A2 or DECEMBER, 1975 41 Fig. 10 shows the intermodulation of A4 by El (or 44 -Hz by Hz) when they are mixed in equal portion. The IM at high is astonishingly low. The type of distortion on A4 at an average power of 60 watts is composed of both amplitude and phase modulation, with 3 per cent peak -to -peak amplitude modulation and 5 degrees peak -to -peak phase modulation at 41 Hz. At this drive level, the woofer shifts position toward the listening area by an amount corresponding to 0.02 milliseconds of air path delay, which is totally inconsequential as far as the sonic effect on the frequencies which the woofer is called upon to handle. The IM falls rapidly with decrease in power to a plateau of about 1.3 percent. power levels The Nakamichi Monitor has an acoustic transfer function that, at frequencies below 350 Hz, has a shelving type increase above 0.1 watt. This is approximately a 0.6 dB increase in gain, somewhat like a program expander. This should give a mild emphasis to sound peaks above this power level, but will also cause a small lateral spread of musical partials in the stereo stage when instrumental voices are in the one watt and above power range. This characteristic is the reason for the unusual low power harmonic distortion property. The crescendo handling test was passed easily for three sigma noise peaks up to 350 watts. This means that inner musical voices will not become smeared for sudden momentary random signals, such as applause, that have average power in a 20 kHz band that is 20 dB higher than the average power of the musical tone it is riding over. The energy -time response, which is the square of the true amplitude of the impulse response, is shown in Fig. 11. The main peak at 3.15 milliseconds. The subsidiary peaks are due to diffraction and scatter within the enclosure. The peak at 9 8 7 6 5 4 3 2 1 0 01 lo POWER 10-IM distortion of A4 or Fig. 100 -WATTS 440 Hz by or E1 41 Hz mixed one to one. FRONT SURFACE OF ENCLOSURE TWEETER VOICE COIL WOOFER VOICE COIL 10 -20 w zw 30 Y -40 2.75 3.0 3.5 40 TIME- MILLISECONDS Fig. 11-Energy-time response. AUDIO t 45 U lJl_ 50 which is the largest contributor, is due to sound from the tweeter that travels along the front grille and reradiates from the top of the enclosure. Other subsidiary peaks are due to reflections from grille and associated housing. This is not as good an impulse response as one might expect from a professional monitor speaker. The problems are associated with the physical housing and manifest themselves in two ways. First, the basic frequency response is made somewhat nonuniform for these peaks, and, second, there is a distinct change of timbre with listening position for the very highest range of frequencies that gives an effect equivalent to polar response irregularities. The average energy is uniform, as has been shown, but the details of the response will be very slightly modified. The sides of the Nakamichi Monitor System are rounded, which is a correct way to minimize,diffraction from the vertical edge discontinuities. This is why there are no broad "clumps" of energy more than a half millisecond following initial sound. The first dominant arrival at 3.15 milliseconds has the peak of its response at 8.3 kHz, which means a relatively bright sound. Ninety-five percent of the sound energy arrives within 3.3 milliseconds, and ninety-nine percent arrives within 3.7 milliseconds. 3.6 milliseconds, Listening Test Nakamichi Research provides very explicit recommendations concerning the physical placement of their Reference Monitor System, which were followed to the letter. Four "standard" cinder blocks, measuring 71 X 71,4 X 151 in. were placed under each speaker to bring them 15 inches off the floor. At 110 lbs. (50 kg) per speaker, the use of cinder blocks is quite logical, if incongruously undecorous. A cloth covering was placed over the cinder blocks prior to hefting the speakers into place. Standing more than 15 in. away from the back wall, these monoliths make a formidable obstacle that should not be placed where the unwary guest might collide with them. Believe me, the speakers won't budge. The speakers were tried in both a forward -facing configuration and rotated toward the listening area. Because of discernible polar characteristics, the angled position was chosen for the listening test. A word of comment on speaker hookup is in order. The Nakamichi Reference Monitor clearly shows its professional heritage by the fact that connection is made to a four -pin XLR type connector. There is an XLR receptacle on each side and they are provided with a locking cap to cover the receptacle not in use. Though it appears this system was originally designed for flush wall mounting, Nakamichi wisely recommends pulling it away from the wall. One problem might arise with the Cannon XLR-4-11C plugs which Nakamichi supplies for hook up. Despite the good instructions supplied, this is not a task many non-professional users will enjoy, even if they have a soldering iron. Nakamichi also recommends that the user employ a fast acting 2.5 -ampere fuse to protect the loudspeaker from damage. In view of the substantial investment which this system represents, this is a wise precaution. Overall listening impression is that this system is very analytical in that there is very little coloration of timbre over most of the frequency range. It is a sound, or lack of it, that is needed in certain studio applications. But it will not blow your ears off with robust midrange peakiness, if that is the kind of "monitor" you are expecting. While there are definite polar response "fingers," these can be eliminated by rotating the speakers toward the listening area. DECEMBER, 1975 75 www.americanradiohistory.com AmericanRadioHistory.Com The low bass response was found to be somewhat thin, and in fact, a check was made to be certain that the polarity of one channel had not accidently been reversed with respect to the other. Though this thinness was most noticeable with super low frequency organ music, percussive bass sounded clean to my ears, with no trace of a boomy hangover. The bass spectrum, once it gets going, is so well balanced with respect to the midrange that no position of pre- amplifier tone control sounded more accurate than flat equalization in the low end. Piano music sounded most accurate with a very slight cut in treble, corresponding to about 2 dB at 10 kHz with the Marantz preamp this reviewer uses. The overall response was a bit bright with what to be a mild upper treble peak. There were two subjective or personal impressions that detracted from perfect performance, which might not be judged as detrimental by others. One of these was a slight sense of compression of dynamic range on program peaks. This showed up as a strained sound on orchestral and vocal peaks in what seemed to be the 3 -to -5 -kHz range. To those who know the sound I refer to, it was a very mild case of "cone cry." Perhaps a part of this two-way system is called upon to carry too much of a The second subjective impression was that horns appeared somewhat back in the stereo stage, though the genhad was that the stereo stage was comeral impression pressed in depth and pulled forward to lie on a surface passing through the location of the loudspeakers. But these were the only problems I sensed. In general, stereo lateralization and accuracy of instrument location in angle is exceedingly good. Center -channel vocals come smack from stage center and do not broaden into "jolly green giant" voices. The sound of percussion is very good and overall transient accuracy is excellent, although not as well articulated as the very best electrostatic top ends I have heard. One of the interesting observations of the Nakamichi Reference Monitor is that it can be listened to at low sound levels without losing balance. This is a trick of the trade with which one can quickly separate the clean loudspeaker from the impressive, but peaky responsed loudspeaker. This Nakamichi is definitely clean in spectral balance. At a price of $1,200 per speaker, the sound had better be good, and Richard C. Heyser the Nakamichi's sound is good. I Check No. 95 on Reader Service Card load. BGW Systems Model 500D Basic Power Amplifier MANUFACTURER'S SPECIFICATIONS Power Output: 200 watts per channel, both channels driven into 8 ohms, with less than 0.1% total harmonic distortion or intermodulation distortion, from 20 Hz to 15 kHz; 251 watts per channel, both channels driven into 4 ohms, with less than 0.25% total harmonic distortion or intermodulation distortion, from 20 Hz to 15 kHz; 501 watts mono mode with less than 0.25% total harmonic distortion or inter modulation distortion from 20 Hz to 15 kHz. Signal -to -Noise Ratio: 110 dB. Damping Factor: 500. Dimensions: 19 in. W x 7 in. H x 12 in. D. Weight: 49 lbs. Price: $839.00 The BGW 500D, yet another addition to the 20 to 30 stereo power amps in the 150 to 200 watt per channel power class, appears to be quite well made, about as solid as a brick. The basic chassis is a rectangular steel box with the top open. The power transformer is appropriately large and is mounted on the inside left (as viewed from the front). An L-shaped bracket is attached to the internal floor of the chassis and has mounted to it two 10,000 NF/75V capacitors, a diode bridge rectifier, a silicon controlled rectifier, and a three -terminal barrier strip to terminate the incoming line cord. Two large power resistors are mounted on the bottom of the chassis; one is in series with the a.c. line to reduce inrush current and gets relay shorted after a short time delay, and the other is in series with the SCR which is wired across the plus and minus terminals of the power supply. On the inside rear of the enclosure is a barrier strip for primary strapping of the power transformer, the cooling fan, and a PC board containing the turn-off time delay and the crowbar control circuitry. Covering the top of the enclosure (except for about an inch in the middle) are the two heat sink/amplifier modules. These are large sinks with two rows of six TO -3 power transistors mounted on them. On the non -fin side of the sinks are the amplifier circuit boards. Connections are made to the power supply's input and output through an 11 -pin connector mounted on the circuit board. Over the top of the heat sinks is the top cover of the unit, which is solid on the top and rear and open at the left and right ends. The arSCR w Fig. 76 1-Rear panel. Fig. 2-Interior view. AUDIO DECEMBER, 1975 Negative feedback is taken back in two loops. One loop, is around the predriver and output stage, and the overall loop, through R5 and C3, is around the total am- rangement is such that the air flow from the fan comes up between the heat sinks in the middle and is forced to travel horizontally through the fins to the exit ports in the top cover. All in all, a very effective cooling scheme. The front panel, which is 3/16 -in. thick, has two beefy handles, a rocker -type power switch/circuit breaker, and a LED power -on indicator. On the rear panel are two pairs of fiveway binding post speaker connectors, two phone -jack input connectors, the power cord, and a protruding 1/4 -in. shaft that operates the stereo/mono switch. via R9 and C9, plifier. Mono full -bridge operation of this unit is selected by pushing in the shaft on the rear panel. A switch on one amplifier's circuit board converts one channel to a unity gain inverting circuit with its input fed from the output of the other channel. The load is then taken between the hot terminals of each channel and effectively doubles the output voltage giving the per channel four -ohm power into a single eight -ohm load. There is no instantaneious VI limiting in this circuit, adequate safe area being provided by the multiplicity of output devices. A circuit on the time -delay circuit board senses plus and minus d.c. levels in the output of each channel and if considered excessive, triggers the SCR crowbar device which shorts the plus and minus 75 V supply together through a two -ohm resistor. This discharge of the power supply causes the primary circuit breaker to open, thus shutting off the amplifier and protecting the load. Circuit Description The first stages of the 500D are those of a LM318 operational amplifier. The output of the op amp feeds a complementary pre -driver stage, Q1 and Q2, operating at a collector current of about 25 mA. Considerable emitter degeneration is present in this stage, which raises the output impedance, giving the output stage more of a current source, improves stage linearity, and helps the stage quiescent current stability. Connected between the collectors of Q1 and Q2 is the bias shunt regulator, Q3. The output stage is a quasi -complementary emitter -follower. Q4 and Q6 are Darlington connected followers, driving the composite pus half -cycle output transistor, consisting of Q8, 10, 12, 14 and 16 in parallel. Q5 is the input to the compound -connected minus half cycle side of the output stage. Q7 is an emitter -follower, driving the minus half -cycle composite -output transistor, Q 9, 11, 13, 15, 17 in parallel. Q6 and Q7 drivers are RCA multiple -emitter -site devices, and all outputs are RCA single diffused types. I CI R2 1K i OPT R3 ttC5 R7 4.7K 3 R4 01 20PF F R8 100 C7 CII T'20PF 20 r µF 3.9K R5 15K 14 = 012 014 016 10 R29 4 R31 R33 R35 R37 R23 I.0K 10 07 05 09 RIB 011 013 015 017 100 C8 02.047T 47K 010 R20 R16ep2 680 08 R27 C15 RI T7PF 004 106 C13 210 F 1K -C3 InF 100 680 C6 C R17 R13 T.047 ICI 47K The 500D was listened to on the reviewer's arrays and a pair of Dahlquist DQ-10s recently loaned to Audio for amplifier review purposes. The bass reproduction on this amplifier is excellent,giving good control of the DQ-10 woofers. It is relatively free of upper bass boominess and has good lower bass punch. The midrange sound is similarly good, though the high end sound has a bit of brightness or edginess. RIO 3.9K r C2 Listening Tests C17InFT R9 a7PFT e 47K C16 InF R24 R28 100 10 R30 R32 R34 R36 R38 D3 -1 2.5K1% C4, 5074F C18 O.1 5 O8 09 PIN I 2 3 CIRCUIT OUTPUT OUTPUT TO PIN 6 OF OTHER CHANNEL 4 -75 5 -75 6 TO PIN 9 OF OTHER CHANNEL PIN 10 CIRCUIT POWER SUPPLY GROUND 7 4 O 3 J1 2¡¡ II - IQ C22 0.1 D4 R25 30 C19 0.1 R26 2.7 S2 LI , 0.574H + INPUT 8 9 SIGNAL GROUND 10 +75 II + 75 NOTE:- SI SHOWN IN STEREO POSITION Fig. 3-Schematic of BGW 500D. AUDIO 77 DECEMBER, 1975 www.americanradiohistory.com AmericanRadioHistory.Com Measurements The 500D was first run at one third of rated power, 66.6 watts, into eight -ohm loads for one hour with a 1 kHz test frequency. Under these conditions, the fan alternately ran at low and high speed. The unit was then run for a second hour into four -ohm loads. Rated power into four ohms is 251 watts per channel and the test power was therefore 83.7 watts per channel. This time, the fan ran continuously at high speed and exhausted plenty of heat. Fan noise at high speed is fairly loud and could be objectionable to some people in a home music installation but would probably be okay in industrial and PA applications. However, if one is really pushing the amp hard and the fan does go to high speed, the resulting music level would in all probability drown out the fan noise. All things considered, this unit has excellent thermal capability and is one of the few units on the market that has adequate cooling for low impedance loads. Voltage gain was measured and found to be 20X or 26 dB, which is normal gain for power amps. IM distortion along with 1 kHz THD is shown in Fig.14. The measured behavior of this amp is different from any other thus far in that the IM and 1 kHz THD are virtually independent of power over a TOTAL I M IKHz THD ripple. X ó 0 ó - 01 E OF 10mW I00mW Figure 6 shows a 80-V p -p, 200 -watt, 50 -Hz square wave 8 ohms and a 10 V p -p, 10 -kHz square wave into 0.22 if. The 50 -Hz waveform exhibits relatively low tilt which is de - M- into 5th 6 7th HARMONI 0.001 IOW 1W very wide range. The predominant harmonic distortion is even order, stemming from a gain imbalance per half cycle. It wasn't determined just where in the circuit that this gain imbalance occurred, but it could be in the way the unit is internally grounded and/or in the output stage where the minus half cycle or compound side has more gain than the cascaded emitter -followers in the plus half -cycle part of the circuit. The distortion products on IM are essentially a 60 -Hz square wave which indicates even -order nonlinearity, and on THD, the residue looks like a full wave rectified sine wave, again indicative of even order nonlinearity. There are some higher order odd harmonics present also, mainly due to crossover distortion and are shown in Fig. 4. The fact that they peak at about 100 mW instead of disappearing below 1-10 watts, as has been characteristic of the better amps tested, may be partially responsible for the slightly harsher high end exhibited by this amp in the listening tests. The predominance of even -order products may be responsible for the apparent extra brightness observed. Figure 5 illustrates the one -watt frequency response and THD vs frequency and power. The high end rolloff is at a lower frequency than usual, being 3 -dB down at 80 kHz. The THD curves reveal increasing high frequency distortion with decreasing level. This is mainly caused by crossover or notch distortion where the magnitude starts to increase with frequency due to the falling compensated open -loop -gain characteristic. The magnitude of the notch starts to override the half -cycle gain unbalance, which is about 0.03% above 3 kHz. The 200 -watt curve has the lowest magnitude, but starts to rise above 13 kHz or so due to early peak clipping due to common mode conduction in the single -diffused output devices dragging down the power supply. There were no observable aberrations in THD near 120 Hz due to beating of the signal test frequency with the 120 -Hz power supply IKW I00W POWER OUT Fig. 4-Distortion versus power into 8 -ohm loads. 0 10Hz 100Hz 10KHz n I00KHz i INPUT FREQUENCY RESPONSE. 8n LOADS -I0 -20 0.3 0 x ATT 0.2 200 WATT IOWATT THD VS FREQUENCY & POWER 8n LOADS 01 100 IK FREbUENCY 50 WATT OK 20K - Hz Fig. 5-Upper curve, 1 -watt frequency response with 8-ohm loads (note break in scale at 100 Hz -10 kHz); lower curve, THD versus frequency and power with 8-ohm loads. 78 6-Top curve, 200-watt, 50 -Hz square wave with 8 -ohm load (scale: 20V/cm, 5 mS/cm); lower trace, 10-V p -p, 10 kHz square wave into 0.22 -pf load (scale: 5 V/cm, 20 µS/cm). Fig. AUDIO DECEMBER, 1975 sirable. A reader recently suggested that amplifiers be tested with capacitive loads in the range of 0.05 to 0.2 pF to see if any real amplifier instability occurs. Accordingly, the second trace of Fig. 6 shows the 500D's behaviour with 0.22 pF. As capacitance is raised from zero, the circuit starts to ring at about 0.05 pF and rings more and more with decreasing resonant frequency as capacitance increases to the low micro farad range. With this amplifier, no sign of amplifier instability per se was observed. The ringing shown is caused by the RLC network formed by the series buffing inductor typically paralleled by a resistor in the 1-15 ohm range and the capacitance load itself. Fig. 7-10-V p -p, 10-kHz square wave into, top, 2-pF load and, bottom, 8 -ohm load. (Scale for both: 5 V/cm, 20 pS/cm. Figure 7 is for a 10 -kHz, 10-V p -p square wave into a 2-pV load and an 8 -ohm resistive load. Ringing with 2 pF is typical of other solid-state amps. The rise time of the resistive load waveform is slower than most other solid-state amps, reflecting the designer's philosophy on required or desirable bandwidth. Of greater interest in this regard, however, is the fact that the rise time as a function of signal level is more constant than any amp so far tested, being about 4-5 µS. Furthermore, at 80-V p -p, the shape is still exponential instead of straight sided which suggests that the amplifier isn't allowed to slew rate limit by the relatively slow overall rise time. (See top trace of Fig. 10.) Fig. 8 shows behaviour at 20 kHz into a 1-µF reactive load. The top trace is for square wave drive. Attempts at higher levels simply blew the primary circuit breaker. The level that was achieved (40-V p -p) is suggestive that the amplifier is behaving equally for plus and minus transitions and would probably look good at higher outputs if the breaker would permit. The sine wave level is 40 V rms or 200 volt -amps. THD under these conditions was 0.4%. The top trace of Fig. 9 is an 80-V p -p, 20 kHz square wave 8 ohms. Note the rise and fall portions are exponential in shape, and both transitions behave about the same. The into Fig. 8-Behavior at 20 kHz into 1-µF load. Top, square wave; bottom, sine wave. (Scale for both: 20 V/cm, 10 pS/cm.) blurring at the corners is a 120 -Hz power -supply -ripple modulation effect that decreases as power is reduced. The lower trace is for a 2-dB overdrive beyond the onset of visual clipping with a 20 -kHz sine wave. Not evident in this trace is the sudden reduction of peak amplitude when clipping occurs, which must be accompanied by increased common mode conduction in the output stage, thus dragging down the power supply. "Sticking" per se is relatively absent. Damping factor was measured as a function of frequency and varied from 225 at low frequencies to 200 at 1 kHz, decreasing to about 25 at 20 kHz. Output noise as a function of measurement bandwidth is shown in Table I below. The higher noise level in the 20 Hz to 20 kHz band was caused by line harmonics, and the 122 µV figure is 110 dB below 200 watts into eight ohms-quite good. Power at 1 kHz at onset of visual clipping into four-, eight-, and sixteen -ohm loads was 380, 231, and 129 watts, respectively. In summary, the 500D is a strong, well-built amplifier that should be quite rugged in use, especially with lower impedance and capacitive loads. It would be a very excellent choice as a woofer amplifier in a multi -way system. As a wide range amplifier, the 500D will drive difficult loads with Bascom H. King stability and safety. Check No. 96 on Reader Service Card into 8 -ohm load; lower curve, 20 -kHz sine wave into 8 -ohm load with 2-dB overdrive. (Scale for both: 20 V/cm, 10 pS/cm.) Fig. 9-Top curve, AUDIO 20 -kHz square wave Table I-Output noise as a function of bandwidth, in pV. Right Bandwidth Left 20-20k 400-20k 122 60 70 63 79 DECEMBER, 1975 www.americanradiohistory.com AmericanRadioHistory.Com Directory Addenda Audio General 1631 Easton Road Willow Grove, Pa. 19090 Gale Electronics Sennehiser Electronics Corp. 10 West 37th St. New York, N.Y. 10018 Amtroncraft Kits, Ltd. McIntosh Laboratory, Inc. Stark Designs Co. 7621 Fulton Ave. West 13th St. New York, N.Y. 10011 1 Two Chambers St. Binghamton, N.Y. 13903 c/o Roth-Sindell Suite 102 540 Kelton Ave. Los Angeles, Calif. 90024 North Hollywood, Calif. 91605 The listing for Infinity's Servo Statik IA on page 86 of the October Directory contained several errors. System type electrostatic, rather than ported, and has a sealed bass comode operating below 70 Hz. It does not have a Walsh tweeter. is STR 3000 Orange Grove Ave. North Highlands, Calif. 95660 Jensen Sound Laboratories notes that the prices listed for their speakers in October's Annual Equipment Directory are for speaker pairs. AMPLIFIERS NOTES All models solid-state except where mod. no. preceded by (T). Basic power amps have mod. no. preceded by (BI. MANUFACTURER (K) indicates kit price; (W) wired. (0) with mod. no. indicates quad. AMTRONCRAFT (B) UK -192 UK -185 25 10 5-80 1.0 20-20 0.5 12%x9x48/. 4 80 0.07 3 5 1139.951K) Requires power supply. 99.50(K) 4 PREAMPLIFIERS NOTES All models solid- MANUFACTURER state except where model no. is preceded by (TI. (K) indicates kit price; (W) wired. IO) with mod. no. indicates quad. AMTRONCRAFT AUDIO GENERAL UK -175 UK -118 511 2 2020 5 0.005 0.005 80 2.3 9x655x4'/. 0.1 1.0 80 0.3 70 0.23 2 11'/sx7x4 38k 0.23 14e10x5''/. 15 99.501K) As above. 400.00 No tone controls. ±0.1 80 Powered by amp. 115.50IKI AUDIO DECEMBER, 1975 SPEAKERS D ,' MANUFACTURER eCi , 4 X00 ,, N ó moo D' o o4' ti m moo .yu D oo, ít at ' ' 5 o ti3 ti3 i0 3ia `o Re Dome M,T ro ?e F 0 tiro GALE ELECTRONICS GS -401 STARK DESIGNS SR -1 Attus. 10 43 5 Cone 1 Dome M,T 40.20 79 40 SR -2 Ac.sus. 12 38 5 Cone 1 Dome M,T ±5 35-20 81 50 SR -3 Ac.tos. 12 38 (215. Cone (211 Dome M,T 35-20 ±3 81 60 55.22 ±5 93 18 1.5k 8 37-21 ±5 37-21 ±5 93 30 6 93 30 1.5k, 10k 1.5k 40-20 ±5 30-21 ±4 40-21 95 75 6 91 125 94 200 93 200 1.5k, 5k 300, 5k 900, 5k 150, 3k 100 150 Ac.sus. Cone (214 (218 N Ported Beta STR 8 75 - Dome Gamma Ac.sus. 10 42 3% Gamma II Ac.sus. 10 42 - P-10 Ported 10 65 P-12 Ported 10 65 Sigma II Ported 12 - Dome 3% PZ - 3% Dome 4% Dome 3%, Dome T 4'/, Dome 12) Dome M,T 4% Dome 12) PZ M,T Dome Omega II III' Theta REFERENCE NOTES: (11 Dual slot (2) Cone 8 (2) Dome W,M,T (3) PZ PZ T 12 5k -25k -' 0 O 8 4.5k 450, 4.5k 450, 4.5k 8 8 24x15 x11'/, 24x15 x14 Wal. - NOTES % 3Q 385.00 `Choice. 165.00 (1) 24x163 Wal. Vinyl 16x9% 4k x12'/, Vinyl 2314x14% x12% 25%x1314 x153: Wal. 31:x15% Wal. 8 x15%, 3114x1514 x15%, 3114x1514 8 8 Wal. Wal. 195.00 11) Each 240.00 57 Each Cloth, blk. Cloth, blk. Cloth, blk. Wal. x31% 6x6x1214 20 48 Foam, blk. Foam, blk. Foam, blk. Cloth, blk. Cloth, blk. Wal. 2314x14% Each Foam 5 colors Foam ' 5 colors x14 6 42 Foam 5colors Wal. x10 23-18 ±3 os m x10%. 450, ±4 PZ . 2314x13 8 5k t3 i fe c' me F Cio 475, 100 .. ó fo Qc° 0} 55-20 ±3 o oá., io ° . Q ro' D oe oo oc (1) (2) 18 74.50 Fused 43 179.00 Fused 43 108.00 Fused 65 249.00 Fused 80 349.00 Fused 85 399.00 Fused 170 649.00 5 149.00 Pair Fused, bi- and tri-ampable. 'Add-on tweeter; fused; for parallel operation. Rotatable High Frequency Dispersion Unit. (2) Rear mounted mid and high frequency drivers. MICROPHONES Z , MANUFACTURER A. SENNHEISER í.C C¢ e o e o o m00 o é V -146 XLR 15 - 30-17 -146 XLR 15 - 200 50-16 -151 XLR 15 200 50-15 -151 XLR 15 - 200 30-20 -151 XLR 15 - 750 80-12.5 -151 5 800 50-12.5 -151 5 10 50-20 -115 XLR 10 40-20 -121 XLR 10 40-20 -121 XLR 15k 50-15 -135 5 Phone 15k 50-15 -135 5 Phone 40-20 -141 10 Metal Dyn. Plas. MD -416 Card. Dyn. Metal MD -413 Card. Dyn. Metal MO -211 Omni. Dyn. Metal MD -402 Super card Super card Dyn. Metal nickel Satin nickel Satin chrome Chrome Dyn. Plastic Plastic MKH-815 Beam RF Metal MKH-415 Club MKH-435 Card. MKE-201 Omni. MKE-401 Card. Satin nickel Satin chrome Satin chrome Satin nickel Satin nickel Enamel 1.5k Metal RF cond. RF cond. Elect. Metal Metal tond. Metal Elect. tond. MKE-2002 Metal Elect. 4o 30-20 Dyn. card. Card. cond. 40 e. - - O~ c` Óe S , .OCL, 4 -° 200 Super MD -421 MD -412 Chrome 4 -ó ...5.- Jr C CO` o 40 P k, oo' oa c" 200 MO -441 plastic Chrome plastic Satin .go ß, 041 CO eC to .T` moi; Do } ,4 op°' ó 5 :C ' ó Z~/ .c Q cf 4. äe e Q.o oo 1 10.6x 1.4x1.3 7x1.8 x1.7 16 5/8 x 27 275.00 14 5/8 193.00 7 x 2 11 5/8 180.50 5x.87 10 5/8 140.00 5x.87 4.5 5/8 214.50 Phone 5.7 o .83 6% Clamp Phone 5'/,x11, 2.1 Clamp 72.50 22x14 14 Clamp 629.00 10x14 6 Clamp 529.00 7'/,x14 5 Clamp 495.00 7x% 4 Clamp 126.50 7x% 4 Clamp 147.50 - - NOTES Adj. Freq. resp. 50.00 x 114 DIN 2 330.00 tond. 'Double mike for bi neural stereo. - HEADPHONES . ,xf MANUFACTURER 4i ítOo SEN NH E ISER HO -44 HD HO HD HD AUDIO -414 -424 -4004 -110 a haQom Dyn. Dyn. Dyn. Dyn. Dyn. ~ a" . iñ0 ` 40-15 20-20 16.20 100.6 20-20 0' `` 640 2k 2k 17 200 .fao .,-"e fc Doc` Qo . 5v É ° 1 o0 É cf. o} 5" 94 102 102 82 98 íT Bk 18k 18k 5k 7k caPT C ti m ó.`'tr 1.5 i 1 1.5 1 5 NOTES 1 c 10 10 10 25 i ti' r`o 1.2 4.8 6.7 0.6 10 29.75 49.75 79.95 12.00 111.50 Open -aire design. Deluxe version of 414. Mono. for TV listening. High isolation, for monitoring. 81 DECEMBER, 1975 www.americanradiohistory.com AmericanRadioHistory.Com The Column J LPsurface noise flow there's a better way to give it the brush. Since all modern LP's are made of vinyl, they're all subject to two kinds of surface noise-from dust in the grooves and from static electricity. Now there's a way of eliminating both problems effectively (and prolonging the life of your records in the process). It's our new A.E.C. Megafilare (million bristle) record brush. Designed for us By London FFRR, this easy -to-use brush features special electrically conductive bristles, which carry away the static with the dust. And they do it without the need for messy liquids-which can eventually clog the grooves. A.E.C. Megafilare brushes (and London FFRR-designed, ultra -precise A.E.C. Posiscan cartridges) are available wherever C/M Laboratories products are sold. Or write us at 327 Connecticut Avenue, Norwalk, Conn. I INTERNATIONAL, INC. CHRISTMAS GIFTS... FOR YOUR RECORDS. Check No. 8 on Reader Service Card Atlantic Crossing: Rod Stewart Warner Brothers BS 2875, stereo, $6.95 Sometimes it's fairly interesting to take a wild animal and domesticate him, but such experiments aren't very interesting if extended over a period of time. This is Rod Stewart's album in which the backing musicians are dressed in business suits rather than dungarees-producer Tom Dowd (replacing regular producer Rod Stewart) has taken Rod out of the garage band bash sessions and placed him in front of seasoned session men who play with precision/taste more often than exuberance/flash. Sometimes it works (mostly on the slow side), and sometimes it doesn't-but this is an experimental album rather than your usual Rod Stewart disc. I like it quite a bit, especially compared to the majority of records out on the shelves, but it's as flaw -laden as Alice's Welcome to my Nightmare or Roger Daltrey's solo efforts. You can take the man out of the jungle, but you can't totally take the animal out of him-but Tom Dowd almost does from time to time. Dowd knows more about getting a band to sound right than getting the most out of a vocalist-Stewart doesn't sing his best on the fast side, particularly on Stone Cold Sober. The 82 players seem to be hitting the right notes, and the track seems to sound good, but somehow Stewart has the kind of voice that rocks best when pitted against a chunky rhythm guitar like Ronnie Wood's than a precise rhythm section and rather restrained guitar. Good old Roddy knows how to deal with a slow tune when the backing is right, and songs like I Don't Want To Talk About It, the Al Green isms of This Old Heart of Mine, and Sutherlands' Sailing come off as sterling gems with no comparable tracks in the entire Stewart catalogue. When Stewart's done a ballad in the past, it's usually been marked by the same rough edges that characterize his up tempo numbers. Now his ballads are smooth, well -crafted pieces of plastic, but his rockers lack the raunch-I suppose how much you like this album depends largely upon (1) how important you think raw punch is to Stewart's music and (2) whether you value Rod's rockers higher than his "down" tunes. Don't get me wrong-I enjoy listening to this album quite a lot, and Rod'll shine through any muck that you place around his voice. He's one of the most recognizeable vocalists on the scene today, and this is his first al - AUDIO DECEMBER, 1975 bum to sound like the "finished product" that I've heard Rod gripe so much about, he being a great defender of looseness and spontaneity. just hope that in the future Rod recognizes the importance of the "ka chunk" to his music, and with Ron "He's Good -Looking, Girls" Wood moving over to the Rolling Stones (we suspect) and The Faces dissolving, my guess is that the Stewart -Wood collaborations may re-emerge as the dominant force on Rod's solo outings, as the reason for all this gloss on Atlantic Crossing is just to prove that there's a difference between Faces albums and Stewart albums. Point proved, let's get Jon Tiven back to basics. Realistic? Pioneer? Marantz? I Sound: A - Performance: . N instruments (Ronnie Montrose's guitar is heard on one cut). Moog bass, Arp strings, Fender piano, Hammond organ, and other brand name sounds provide an exquisite framework for more relaxed vocals than you would ever expect from a Spooky Toother. The lyrics are in keeping with our times. Rock frankly has run out of words and in general lost interest in lyrics other than as a hook to give the title some meaning. On this album, except for the poetry of Dream Weaver, poetry takes a minor role in the whole of any song. In this time, where Do-ahah and Da-da-diddy-dum are definitely a no -no, an artist like Gary Wright has a real difficult time of it keeping current and keeping himself inside the framework of tried and tested Rock -type tunes. The lyric is needed to preserve the identity of the music as Rock and Roll, and also to satisfy old fans from his Spooky Tooth N AUDIO DECEMBER, 1975 83 iB N f IN W Mi M{ Ip . tu; Who's #1 in audio equipment? Three famous national component brands, each with fine equipment at all the traditional price points, each with fine magazine ratings and lots of customers. Naturally we at Radio Shack like to think Realistic* - top dog. Our reasoning goes like this: the entire worldwide Radio Shack Realistic has over 4000 stores system-and 21 years of manufacturing experience. Realistic has exclusive Glide -Path* and Auto -Magic* controls. An audio consultant named Arthur Fiedler. Service like no tomorrow. And prices like yesterday. Maybe a better question is who's #2? is ftadue Ihaek Great sound since 1923 Over 4000 Stores/Dealers in USA, Canada, England, Australia, Belgium, Germany, Holland Registered Trademark Check No. 36 on Reader Service Card ezzge eMele Could the ultimate system be all Crown ? It depends on how you define "ultimate". But Crown may be the only top- ' .. L..Js` ¡Yv; t.r days. Without them The Dream Weaver would have to face the marketplace as an instrumental disc. Even though it merits this carping about words, The Dream Weaver is successful no matter how you approach it. In striking a balance between his voice and his instruments Gary produces a laid-back, comfortable album that has no outstanding tune or element, other than start -to-finish competence. The whole is greater than its parts and N Realistic STA -225 Stereo Receiver About $400 B The Dream Weaver: Gary Wright Warner Bros. BS -2868, stereo, $6.98 Gary Wright is yet another solo artist who came out of a band that has been around for quite some time. His origin is Spooky Tooth, a band I never could really get a handle on, yet often enjoyed. Wright played keyboards with that band and it's only fitting that, apart from the vocals and the drums of Andy Newmark and Jim Keltner, all the sounds are from keyboard p quality, state-of-the-art manufacturer whose components could build a complete ultimate system. For instance: A CX-824 tape deck, worldrenowned for reliable performance. Connected to an IC -150 pre -amp. With the signal amplified by a DC -300A power amp, proved in many thousands of hours of professional use. Output controlled, monitored and switched by an OC -150. Possibly a VFX-2 for personal control of crossover points. And sound faithfully reproduced by ES -212 electrostatic speakers. All Crown. We think that system would be somebody's ultimate. Certainly ours. Maybe yours. Write us today for the name of your nearest Crown dealer. He'll talk to you ultimately. - crown When listening becomes an art, Box 1000, Elkhart IN 46514 Check No. www.americanradiohistory.com AmericanRadioHistory.Com 7 on Reader Service Card should appeal to many tastes. The ease and smoothness of the performance lifts this far away from the Spooky Tooth mold, as does the superb recorded sound. Gary Wright is maturing right along with his audience. He even avoids hollering even once. He brings home The Dream Weaver with taste, flair, Fred De Van and warmth. Scrawl Award. I listened to it once and then scrawled total loss across the cover. if you are looking for great song writers performing their own material (and Webb is a great writer), try Janis Ian Between The Lines, Columbia PC33394, and Stars, Columbia 3285; Gordon Lightfoot, Cold On The with this one. Maybe I could accept someone less well-known coming up with something like this-maybe Tim Moore, or Michael D'Abo, but I heard this Jimmy Webb album first. This review comes after listening the third time and the red scrawl still applies. Shoulder, Warner MS 42206; Van Morrison, Veedon Fleece, Warner BS Sound: Performance: A 2805; Jackson Browne, For Everyman, Asylum 5067, or even Paul Williams, Here Comes Inspiration, A&M 3606. Avoid this Jimmy Webb album. As good as he is, he just doesn't make it Upchurch/Tennyson: Phil Up- Sound: A Land's End: Jimmy Webb Asylum 5070, stereo, $6.98. This record earns my first Red TDK SUPER AVILYN GUTSOUNDS CHROME AND THE #1 FERRICHROME. INDEPENDENT LAB TEST RESULTS Signaixo-Noise Rano TOR SA A 8 c D 1>' 4th 131 61h 7' 2nd 31u Trh 6ih 1,1 131 1" 1" Distortion (I.M.t Low -Frequency Response Accuracy 1" Mid-Frequency Response Accuracy 1" 2'd 51 5th 2nd 2" 2" 6th 5th 1st 1St 2" 41h Output (0 YO) st 4th 5th Surface Abrasiveness low high high High -Frequency Response Accut acy Maximum Output Level I (3'sthe high 1 TDK's SA advances today's standard of excellence in cassette high fidelity. Until it was developed, chrome and ferrichrome had the soundthey outperformed ferric oxide tapes in extended highf requency response with lower noise. Now, SA outsounds chrome, the #1 ferrichrome, and the leading ferric oxide tapes. SA is compatible with standard Cr02 bias/eq. settings, but you don't have to worry about headwear. Its unique particle soaks up more sound and plays it back with less distortion and noise. Check those test results. There's really just no contest. Super Avilyn delivered the clearest, cleanest sound. More lifelike sound-and for you, that's the ultimate test. Fact is, Super Avilyn is now the state of the art. TDK Electronics Corp., 755 Eastgate Boulevard, Garden City, New York 11530. Also available in Canada. Seven tapes were tested (TDK SA, TDK KR, Scotch Chrome, BASF Chromdioxid, Advent Chrome, Scotch Classic, and Maxell UD) and ranked 1st to 7th. The chart shows the results for 5 representative tapes tested. The following tape decks were selected for use in the tests: Nakamichi 500 & 1000, Advent 201, and TEAC 450. TDK. Wait till you hear what you've been missing. Now! Get 2 free cassettes when you buy 8. Or! Free storage box when you buy two SA C -90's. Limited supplies at participating dealers. Check No. 50 on Reader Service Card Total Loss! B Fred DeVan Performance: D church/Tennyson Stephens Kudu KU 2251, stereo, $6.98. This is a delightful R&B, jazz-rock, Stevie Wonder, Kool-and-The-Gang blend, done with the sensitivity that only pure jazz musicians have. It's performed with the eloquence and assurance of a studio musician who is doing just fine being on other folk's albums (ranging from Cat Stevens, reviewed in Audio, Feb. 1975, to Jerry Butler and Howlin's Wolf). Phil Upchurch is now part of the cooking CTI house rhythm unit that backs George Benson and other CTI stars. CTI is Kudu's parent label, and Kudu is CTI's style and quality, aimed at non -purists (like me). Bassist/guitarist Upchurch and his constant cohort Tennyson Stephens (vocals and keyboards) put on a sterling performance and really show us how well an idea can work. The music is tight, smooth, and professionally executed. Tennyson's voice can not be ignored. It's a sort of blending of Lou Courtney (I'm In the Need of Love, Epic KE 33011) and Les McCann (on any Atlantic). His piano is that tasteful Rhodes sound that Les pioneered, but this is no copy. There is no special cut on this album that stands out above the splendid whole, but there is one I just don't like, Ave Maria. I can't understand why they did it. Don't judge the sum from this one of its nine parts. On the rest of the album the CTI/Kudu creative forces are joined in their normal state of deft perfection. Arranger Bob James and the incomparable Rudy Van Gelder ("master ears") together provide arrangements and recording with a sheen of strings and voices around the basic quintet. The result of all this is a very lovely, easy -to -listen -to album that has its creative feet in many places. It's very relaxed. Its alluring prettiness will tease you to play it often. Just don't take it too seriously. RelaxUpchurch/Tennyson are relaxed (and relaxing). Their music is calm and complete. Betcha the jazz fussbudgets won't think much of it. But they 84 AUDIO DECEMBER, 1975 should understand it wasn't meant for them. Fred De Van Sound: A+ Performance: A Tomorrow Belongs To Me: Sensational Alex Harvey Band Vertigo VEL-2004, stereo, $6.98 Exactly what you get in a big suburban singles joint anywhere in the country-no better, no worse. Strictly a dollar at the door, 75 cents a drink until nine. That's the sort of music it seems to be until you get into the disc. Then it begins to sound like a minor-league version of Genesis (on A Lamb Lies Down on Broadway, Atlantic 401). Let's say it's an amalgam of both. Alex Harvey brings a touch of "kultchur" to trivia, a gourmet treat for London punk -band lovers. It's a step up, or a step down, depending on where you're coming from. This record doesn't offend me, but doubt that I'll ever listen to it again. eliminate noise in your tape recording I Fred De Van Performance: Sound: B+ B - Born to Run: Bruce Springsteen Columbia PC 33795, stereo, $6.98 Here we have the biggest star in Asbury Park, New Jersey being pushed onto the World Stage as T.N.B.T. (The Next Big Thing) produced by a fairly famed Rock Critic (Jon Landau) and refusing to do interviews unless he gets the cover. He's been called the New Dylan since his first record was released two years ago, and certain members of the press have gone on personal crusades for the fellow. If ever there was an advance industry buzz about a record, this must be it. But with a hype that huge, there better be something there. Now I'm not saying that Bruce Springsteen isn't good (heaven forbid he should get a bad review), but I'm not so sure he's God's ultimate gift to rock 'n' roll. His first two albums were excusable because they were dismal representations of the artist, and a few of the songs (just a few) were appealing. This is far more of an accurate picture of Bruce, and although his talent shines, so do his influences. Bruce Springsteen = Bob Dylan + Johnny Rivers + Exile on Main Street + Van Morrison + Eric Anderson + The J. Geils Band + "Not Fade Away" + A Whole Lot More That I Can't Put My Finger On. I've always been a big fan of Rock 'n' Roll Synthesis myself, but I find this whole business of Bruce Springsteen AUDIO DECEMBER, 1975 85 For the first time in tape history, you can record live music on your audiophile recorder and achieve better signal-to-noise performance than professional studio recorders. The new dbx 120 tape noise reduction system provides about 40 dB noise reduction with reel-to-reel, cartridge or cassette recorders. For live recordings, tape hiss and background noise are completely eliminated. For taping off -the -air or dubbing from records or tapes, no noise is added beyond the noise content of the material being copied. (We do not attempt to remove noise present in the original input signal, however.) dbx 120 units also decode the newly released dbx encoded "noiseless" discs which offer over 100 dB dynamic range with no audible surface noise at any listening level. Model 122 is a two -channel tape noise reduction system, switchable to record or play, with a dbx disc decode feature, priced at $259.00. Model 124 is a four -channel tape noise reduction system, switchable to record or play, which will also provide simultaneous record and play for two -channel recording, with a dbx disc decode feature, priced at $379.00. Words cannot adequately describe the experience of listening to recorded music with over 100 dB dynamic range. We don't expect you to believe it possible until you hear it for yourself. For the most dramatic recorded music demonstration of your life, hear the dbx encoded "noiseless" disc at your demonstrating dbx dealer. For complete product information and dealer list, circle reader service number or write to: dbx Incorporated, 296 Newton Street Waltham, Massachusetts 02154 Check No. www.americanradiohistory.com AmericanRadioHistory.Com 9 on Reader Service Card being "The Future of Rock 'n' Roll" very unrealistic, because he's at least knee-deep in the rock 'n' roll past and can't seem to break loose except for an instant. He writes pleasant enough songs, but I can't decide whether it's solely because he knows how to plunder the best. On stage he pays his debt to Jackie DeShannon & Jack Nietzsche by doing one of their songs, writes across, but if we'd once get a chance on record to hear Bruce Springsteen as something other than a writer, those of us who consider records to be the predominantly important historical document issued by any artist could get a feel for his sense of past. And his voice is nothing to write home about-it's closer to a mumble than the primal scream. like the guy, I really do, even more on this record than live. I think it's time that somebody like Jon Landau (who's paid his dues to rock 'n' roll and he does Stones songs, and Spector songs; on record it's strictly original (ahem) material. I suppose he feels his main task is to get the songs he I , -'r...... - - For a !3411811111til . SUPER -SYSTEM, match the 2217 a.._ 1111111--I Ire he -Art" amps I CAN HARDLY BELIEVE MY EARS... VERY VERSATILE & CLEAN-SOUNDING AND I REALLY LIKE THE SWITCHABLEPATCH/NG- 2 " - Mile tee 1.: AUDIO RESEARCH BOSE QUATRE CROWN DYNACO SONY KENWOOD SAE MARANTZ ESS --< ..,d.n_. m w-, with any of these TRUE "State greliMiiillet PHASE LINEAR tti%v' I_: ,..,. wridr,wA,. l,-,m>A.,,.l., BGW I ana SO 0MA,k 1 OM/9N , O/ _y uTsvr 1k.Apaer dA de er2A../ ru e>'7;. vale.. SPECIAL FEATURES ALL PUSHBUTTONS INTERLOCKED to prevent inadvertent program destruction DISCRETE-OCTAVE EQUALIZATION CONTROL of ten octaves on each channel, o 12db each octave FULL -SPECTRUM LEVEL CONTROL for each channel AUTOMATIC CONTINUOUS MONITORING by light -emitting diodes for visual warning of overload in output circuits VISUAL ZERO-GAIN EQUALIZATION BALANCING on music, white noise or pink noise SELECTION OF TEST LITES on or off TAPE DUBBING BETWEEN TWO MACHINES, with optional simultaneous equalizing end monitoring DOUBLE -DUBBING into two recorders simultaneously SEPARATE SYSTEM -SELECTION enables full use of all other functions during the dubbing operation LINE OR TAPE equalization selector AUTOMATIC EQUALIZERDEFEAT when line or tape equalizer is not in use FRONT PANEL TAPE input-output jacks for easy 2nd and 3rd tape recorder hookup access TAPE MONITORING of either tape at any time TWO stereo headphone jacks MONO SELECTOR for left, right or both channels to both outputs REVERSE-STEREO mode TWO low-level phono inputs FOUR independent phono preemps SIX A/C outlets, 4 switched, 2 unswitched ELECTRO -PLATED FERROUS CHASSIS (eight sections) provides optimum shielding to minimize magnetic field coupling SINGLE -POINT system ground connector minimizes ground -loops TWO REGULATED power supplies - jy ldown, S aLL a& tl run, Av.,/ ?r on±i use list any suggested improvements. changea, lams /}t - &. C.57 GUARANTEED SPECIFICATIONS -- ±y, db, 5 Ng to !OD Noe Phono: +r% de, 20 Hz to zo Noe at 1 volt 1119..01% at 1 wit) 1 roll (Trt..01% at 1 volt) PHONO INPUT CAPABILITY: 105mv SIGRALTP.11013E 111s1wl: 100 db belon full output sIC1MLT0.110I3E Phono: ea as below input SIGALTO.NOISE Equalizer: 30 Co Wow a 1 wilt Input UAIN Phono: 63 FREQ. RESPONSE FREQ. RESPONSE a0: Hi -lawn: leu roan .05% IN: Ins than .05% M gale - -- 10. - Hblenl: 21 db OUTPUT INPEVHICE: 600 ohms .QUALIZEAyLEriableefor EQUALIZERS NOW YOU CAN MAKE YOUR SYSTEM SOUND EXACTLY THE WAY YOU WANT IT TO SOUND I minutes. 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MADE IN U.S.A. includes cabinet PE2217 ! right 15,360 Ns to a few .4.1,4ft1' unity gain lcompenation EQUALIZER RANGE: 12 db Peint and 12 db at, Pam t 30, 60, 120, 240. 180. 960, 1920, 3910, )6a0 and .pop - $499.50 .r rod mean. /'eE® fi IrfiTT tTTrrr FREES THE "WHY'S AND HOW'S OF EQUALIZATION," an easy to GUARANTEED to enhance and improve any fine system! lud plug 2 cabin Into your ready 1. aim 20-12 ter ararlas Is lean. and musk., @moment' Nand.bew... 2212 Tape With modals S349.50 understand explanation of the relationship of acoustics to your environment This 8 page booklet also contains many unique ideas on "How Me Soundcrafhmen Equalizer can measurably enhance your listening pleasures." "How typical room problems are eliminated by Equalization," and a "10.point sell.rated Equalization Evaluation Check -List." $299.50 Equaliwonfrt nava cabinet or rea mount.. 1121 NEWPORT CIRCLE, SANTA ANA, CA 92705 Check No. 47 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com I competence?" (this competition CITATION (CUSTOMER COMMENT CARDS ARE ON FILE AT SOUNDCRAFTSMEN) Fuse-AA-1,c I GAN 0000CV 0.Lww.W NY neertray. gwv us I Blues for Allah: Grateful Dead Grateful Dead Records GD-LA494-G, stereo, $6.98 Bay City Rollers Arista AL 4049, stereo, $6.98 Here we have two records which are recordings of a lifestyle more than any kind of musical document. This is not to say that both of these albums lack musical worth, but that ultimately there are more important factors here than the notes played. Any impact that 'these records make in musical history will most likely be in terms of social rather than musical style. The Rollers vs. The Dead is an interesting proposition for a battle of the bands, for the real test is not "Who will play their instruments with less THE PERFECT PRE -AMP - over the years) broke loose within the record industry and got a decent royalty check. As for this album, it might sell fairly well, but it's not the type of record that's going to explode across the nation. Bruce Springsteen simply does not have the kind of voice to make it on AM radio, and if I was 15, wouldn't idolize him, and if I was a 15 year -old girl, wouldn't want to go out with him, so what's the point? Ion Tiven Performance: B+ Sound: B a would undoubtedly be a standoff) but "Do you like music that will help you fall into a stupor or music that will rev your heart to the Nth degree?" Personally, this writer finds being excited preferable to being laid-back, but I suppose that you listeners will have to decide that for yourselves; and when you go to the record shops you will have to ponder the crucial question-which of these two albums to bring home? Let me then present each of these musical associations in their context. The Dead, ah, those bastions of the San Francisco sound championed by Rolling Stone magazine more often than the magazine's namesake, the original hippie band that seems to live forever. There's more hair on this band than on the Bay City Rollers, Slade, and The Rubettes combined! Musically speaking, the Dead are really past their prime, and it seems that attacking them in 1975 is no better than kicking a dead horse (or setting fire to a greaser's hair in 1965) so shall stop. Blues For Allah is one of the best -recorded albums I've heard in a long time, full of crystal clear bass lines (and as Phil Lesh is the only real musician in the band, this is a plus). I 86 AUDIO DECEMBER, 1975 But really, there's about as much energy here as on both sides of George Harrison's last single. But the Rollers, they're another matter entirely. Many people (Clive Davis, Sid Bernstein, et al.) would have us believe that this is what's in store, or in the words of one ex -rock critic, "I have seen the future of rock 'n' roll and its name is Les McKeown." The BCR's sound more like a throwback to early Sixties rock than the trumpets beckoning of what's to come, more or less an amalgamation of Roy Wood, The Four Seasons, and The Archies. There is no brilliant songwriter in the group, although occasionally the Faulkner/Wood team comes up with a palatable tune (mostly Beach Boys regurgitations, but hold no grudges for plagiarism); Yea, the winningest material on their first American album stems from the pens of others. They have funny haircuts, the best of intentions, toothy smiles, amphetoteen rock, and a hot record company on their side-but it's yet to be seen whether a group this limited musically (can't play their instruments for beans, can't write particularly well, sing only in fairly antiseptic voices) can take the public by storm. The Monkees did it once, but think there was more personality there-yet both they and the Rollers were a result of a lot of people in the background (producers, managers) sweating through TV shows, photo sessions, and record dates more than any triumph of innovative powers within the music. But in any case, it's your choice to make, The Grateful Dead or the Bay City Rollers. I'm not sure I'd put my money down for either of them, but Arista and United Artists already have done so with theirs, so suspect you consumers are expected to follow Jon Tiven suit. Performance: A Sound: THE PROIAM TAPE I I I The Brecker Bros.: Randy & Michael Brecker Arista AL 4037, stereo, $6.98. This album is refreshingly different, not everybody's cup of tea, yet even those to whom it does not appeal must respect the strong musicianship it shows. Play it back as loud as your ears and speakers will permit. Study it. It's amazing how many rules of structure the Breckers successfully break with their fresh, inventive, exploratory, and highly personal style. The energy level is high, almost over- Introducing Maxell Ultra Dynamic backcoated/open reel tape. A professional studio engineer doesn't have time for dropouts, wow, flutter, tape noise, static, poor winding, edge damage or erratic tope traction. Maxell Ultra Dynamic tape has the backcoating that eliminates these recording obstacles. That's why the professionols use it. And why you should too. powering. Their sound assaults your ears if you're not prepared for the tight, high-speed, high -sound -level AUDIO DECEMBER, 1975 87 While your Maxell UD tape is running (and the backcoating is protecting your music) you can concentrate on mike placement, sound levels and the more creative side of audio...like shushing the kids in the next room. Maxel Corporation of America, Moonachie, New Jersey 07074. Also cvai (able in Canada. I maxell. For professional recordings at home. Check No. 26 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com trumpet/tenor pairings or the feel of Randy's electric trumpet. Mike's tenor solos are full, heady excursions into the entrails of the tenor saxophone. The instrumental virtuosity both Breckers display is sufficient cause for celebrating the whole album. Once the listener adjusts to the perspective of this music, its unfamiliar elements will be less uncomfortable though on your first LOUD hearing you may be nailed to your seat, transfixed, awed, dazed or confused (or shot out the door). It seems inevitable that the Breckers and executive producer Steve Backer would meet. When Steve was at Impulse Records he (and Bob Thiele) blazed new trails, including pioneering the first quadraphonic -only label. Steve is a perfectionist, closeting himself away from the commercial madness on his hideaway farm in Massachusetts. He always produces some- thing different musically as well as sonically. His Impulse association probably helped change the sound on this album-it's strange, but not like the strident, weird sound which had previously come from Todd Run - Some things hold up better than others. The accepted concept of durability is based on several very important factors. Material. Design. Engineering. Function. And inherent value. Coincidentally, these are also the hallmarks of the Thorens TD -125 AB Mark II. The materials are the finest available. The design and engineering incorporate the ultimate in turntable technology. Functioning flawlessly, it originates state-of-the-art that others have yet to achieve. To match the impeccable performance, this Thorens is constructed to hold up ... not wear down. It has inbred longevity instead of built-in obsolescence. The precision performance of the TD -125 AB Mark II serves as continuing proof of the Thorens determination to remain the classic name in turntables. There are other models, too, starting at $169.95. Elpa Marketing Industries, Inc. East: New Hyde Park, N.Y. 1040; West: 7301 E. Evans Rd., Scottsdale, Ariz. 85260. THORte® dgren's Secret studio where this disc was taped. Randy and Michael came up to New York from Philadelphia in the sixties (even as Rundgren), and they've established themselves as the dynamic duo of the New York studio musician scene, providing trumpet and tenor on hundreds of records in every musical style. Both now in Billy Cobham's band, Randy was the original trumpet with Larry Coryell's Eleventh House (that chair now well filled by Mike Lawrence). This music, put together by the Breckers and Backer shows a different approach, and it's leading up to something good. The Breckers, Maynard Ferguson, Cobham, Coryell, Jeremy Steig, Peter Frampton, Tom Scott, Jeff Beck, Stanley Clark, Michael Urbaniak, Brian Auger, Oregon, Anthony Braxton, Keith Jarett, Rick Wakeman, McCoy Tyner, Les McCann, and Kool and The Gang are all pointing their respective audiences in the same direction. Towards an omni-music. An omnipresent musical awareness and pragmatism that's creatively just a bit ahead of tomorrow. Fred DeVan March on! Procol's Ninth: Procol Harum Chrysalis CHR 1080, stereo, $6.98 Procol hasn't changed in any major way since their inception eight or so years ago, since those who differed in opinion with group leader Gary Brooker (Matthew Fisher, Robin Trower) were promptly thrown out of the group. While the group has gone through temporary transistions, the Procol Harum of 1975 sounds almost identical to the group which produced Whiter Shade of Pale. Though the Booker/Reid team hasn't written a single song on a par with that, save some close misses with The Devil Came From Kansas and a couple of other recent classics, the group still sounds exactly the same. On stage they're unaltered as well. Brooker delivers his vocals adequately, yet his stage presence is lacking-in fact, the only showman in the group is drummer B.J. Wilson, who is an incredible powerhouse. In concert halls, you'll rarely find a group more boring to look at. Still they persist, making one album a year and waiting for the world to catch up with them, waiting for their fan -dom to come together merely through persistence. Their latest album is pleasant, if only because the tunes are typically Pro 88 www.americanradiohistory.com AmericanRadioHistory.Com AUDIO DECEMBER, 1975 ._ rT" +101 colly and the drum sound is given so much attention; this last item must be due to the efforts of producers Leiber & Stoller. One would expect that such famed and accomplished producers (The Coasters, Stealer's Wheel, et.al.) would have some great audible effect on the Harum sound, but no such luck. There are only minor differences-a cleaner wall of keyboards without the Chris Thomas drones, otherwise it's the same. I suppose they'll always stay the same-too bad I can't say the same for their writing Jon Tiven ability. Sound: B+ Performance: C+ The Album of the Soundtrack of the etc.: Monty Python's Flying Circus Arista AL 4050, stereo, $6.98. There's no doubt in my mind that the Monty Python group is not only very funny, but that they're very accessible to U.S. audiences, despite many rumours to the contrary. Just as audiences lapped up TW3, Americans are now guffawing over Python-for a multitude of reasons. Some find MPFC amusing largely for its Britishness. Obviously this is not the reason UK audiences enjoy it; there are many "in" jokes that Americans can make little sense of, except for those who read the London Times. But people like to laugh-whether they're laughing at the British accents or at the ideas is unimportantpeople are laughing at Monty Python's Flying Circus. Even stolid rock critics like me find themselves amused by their TV shows and movies. Britishers have always had a knack for striking the funnybones (and pocketbooks) of Americans, regardless of whether the actual comic material can be heard over the Cockney mum- bling. The question is, can Python's attack, which is highly visual, be translated well enough onto the disc and back up into our mind's eye? Fortunately the answer is yes. They've taken the most rib -tickling bits of their movies, thrown in some conceptual jokes, running commentary, and assorted oddities (which I refrain from revealing to save them for proper presentation), and packaged them all very cleverly. Python devotees will not be disappointed with this record. Be, however, forewarned that this album, like most spoken -word recordings, does not wear well with age-it's not an album you'll get more from in repeated listening. On the other hand, unlike most comedy records, this is good the first time you hear it. Jon Tiven Performance: A Sound: B , ......ur....i :C,, ,...r .. i'1 =-% i -ii 'rÌ r :' - +,s o r=i a .. = lee.- Wee 5 -10 i nw DECEMBER, 1975 89 r i i ii . Ale - ==MI a I= -15 2K 500 1K Frequency in cycles per second 100 10K 5K 16K For the demanding professional, some mike manufacturers furnish a frequency print out as proof of performance. Unfortunately, when it comes to low cost mikes for home use that practice is not only costly, but could prove embarrassing. Besides, you shouldn't expect a guarantee with iiiian inexpensive mike. Or should you? You can if you buy the new Beyer 550. At only $42.50, the Beyer 550 provides authentielezzud cated performance at a price you can afford. And what performance. 11 In one elegant package you get smooth, wide frequency response, omnidirectional pickup pattern, low distortion and high signal-to-noise ratio. Finally, you get the most generous warranty in the industry and that's another way Beyer lays it on the line. Another innovation from Beyer Dynamic, the microphone people. 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Name Street city I AUDIO i ti State Check No. 36 on Reader Service Card www.americanradiohistory.com AmericanRadioHistory.Com ZIP M 616 Our gimmick is no gimmicks at all. Most speaker designers loudly proclaim accurate reproduction as their primary goal. And so they should. Regrettably, it doesn't always work out that way. A booming bass, a peaky midrange or some other dramatic device often suggests something quite different. At Rectilinear, we have always avoided the dramatic..,shunned gimmickry like the plague. Blackmore's Rainbow: Ritchie more Polydor PD 6049, stereo, $6.98. This is what you might call an that became a group: Ritchie more, then lead guitarist in tary and remarkably similar in expression. Here's Norman Eisenberg commenting on the new Rectilinear 7, "The Rectilinear 7... offers totally 'ungimmicked' sound that is low in distortion, extremely transparent and devoid of records just AT12S AT14Sa made the record and saw that it was good, so he kissed Deep Purple goodbye and turned Elf into his band, and thus was born the latest heavy metal thunder. Voila, two bands for the price of one! The album seems to do nothing but threaten Deep Purple's stance as the Top Guitar -based Band in the World. Because even though Blackmore's re- t It safely tracks your records at grams while maintaining response to 45,000 Hz, offering great stereo separation, and reducing record wear ... even compared with an elliptical stylus at less than a gram. Put an Audio-Technica Dual Magnet UNIVERSAL cartridge with genuine Shibata stylus in your good old record player today. It's a great combination for better sound today and tomorrow, and tomorrow. 2 I A BEST FOR 1/2/4 CHANNEL AT15Sa AT2OSLa a u d i o e c h n i ca. INNOVATION / PRECISION member of Purple so company superstructure. Ritchie N.Y. 10454. U1111\U/I U - __ego> as a that Ritchie, enthused with having total control for the first time in two years, decided to turn the solo single project into a solo album project. So it was off to Switzerland and Germany to cut Rainbow, a debut solo LP by our guitar hero backed by Elf, a group from the Deep Purple management Our new cartridges will turn your good record player into a great record player. stylus. up to multi- in his spare time made a solo single, Black Sheep of the Family, with several of his friends. The results pleased both his ears and those of his peers so Check No. 38 on Reader Service Card Perhaps you've tried to track your records at the lowest advertised setting for your elliptical stylus. In the hopes of optimizing performance and reducing record wear. But every footstep threatens to bounce the stylus out of the groove. And big crescendos are simply fuzzy. Should you get a better player? No. Get a better stylus. We have a sensible new approach. A stylus shape that contacts more of the groove wall, to spread tracking force over a greater vertical area. The Shibata Black - Purple, got bored with making Witness our new ContemNo gimmicks. porary Laboratory Series. Isn't that what great sound is all Initial critical reaction about? has been very complimen- Rectilinear album million -dollar rock group Deep any boxy resonances:' And in assessing the Rectilinear 5,Len Feldman was moved to write, "I liked the Rectilinear 5 for its freedom from 'gimmicky' sound, its sense of naturalness:' Rectilinear Research Corporation, 107 Bruckner Boulevard, Bronx, Black - / INTEGRITY ® AUDIO-TECHNICA U.S., INC., Dept. 125A, 33 Shiawassee Ave., Fairlawn, Ohio 44313 Available In Canada from Superior Electronics, Inc. placement (ace plectrum mover Tommy Bolin) can deliver, it is yet to be seen how his semi -jazz style will jell with Purple's, and Ritchie has definitely got his act together. His guitar playing has always been brilliant, but here he plays with more care and thought than previously. I'm certain he realizes that with all the weight on him now, he'd better perform. That's his name on the cover, and if he puts out a terrible record he's got no shelter to hide under. He doesn't pull any punches-from Temple of the King to Still I'm Sad there's a maximum of excitement and a minimum of filler. It could almost pass for a Deep Purple album except the rhythm section is far simpler. Ritchie Blackmore is the focal point, and since hard rock is a guitarist's medium that is important. Singer Ronnie Dio performs far better than he ever did in Elf, spurred on by Ritchie's guitar work, no doubt. The sound is extremely clean and precise (the pressing of the record could be better, but that's not Ritchie's fault). If they can cut it live as well as they do on record (änd Lord knows Purple always exceeded their studio discs onstage) this band will be monstrous in 1976. I'm certainly glad I'm not Tommy Bolin-I'd have a tremendous cloud hanging over my head, because that boy's got a lot to live up to. Jon Tiven Sound: Performance: A 90 www.americanradiohistory.com AmericanRadioHistory.Com AUDIO DECEMBER, 1975 Sabotage: Black Sabbath Warner Brothers BS 2822, stereo, $6.98 Let's have another one just like the other one-here is the new album by perhaps the least cohe- eaker Kits. S rent/competent singers/players of all the heavy metal groups. They're all right, guess, always entertaining and the big difference from one album to the next is in the production and the covers and not really in the music. sort of like them, and sort of don't, but the real impression that this group makes upon me is that they sell extraordinarily well for a group with very little to say. can't understand why they keep it up-maybe Ozzy is just waiting for somebody to call their bluff. If so, this is it: you aren't doing anything revolutionary, creative or particularly interesting other than taking advantage of the public. Congratulations on a job well done, but that's practically all it is. Jon Tiven Performance: ? Sound: B I I I There's one part of your component system you never thought could be assembled as a kit. Money-saving, multi element stereo speakers. Build them yourself to save up to half the retail cost of comparable ready -built systems. And get great sound in the bargain. Send us your name and address and we'll mail you our free 32 -page catalog of speaker kits, raw speakers, crossovers, enclosures and tips on design and construction. It's practically a manual on speaker building. Write or call: I 1-800-426-7736 (toll free) for your free catalog. Futurama: Be -Bop Deluxe Harvest ST -11432, stereo, $6.98. 4eokeiIcib Bill Nelson, lead singer/ songwriter/guitarist/keyboardist in this group, is an adventurous sort who has taken nothing for granted. He disputes the proposition that only selfindulgent keyboard -based groups can play around with time signatures, he trifles with territories that musicians dared not tread previously, and he is clever with words-all within the context of the three-piece hard rock band. And this band, Be -Bop Deluxe, may well be the rock 'n roll band that the world has been waiting for. For Nelson is the fusion of the rock 'n roll musician and the rock 'n roll person na and can defend either position with equal strength and grace. On first listening, the album is stupefying, and it's very difficult to grasp the changes (although the personality is readily identifiable). Something like Stage Whispers or Sound Track is pretty mind -boggling when it first hits you, but certain things become instantly clear: the man knows how to rock and he knows how to play guitars though these things are not necessarily paired. Keith Richard sure knows how to rock and the world loves him for it, though his technical prowess on his instrument is not especially astounding while John McLaughlin is the opposite case. But at last, in Bill Nelson we come to a being who has the discipline to practice and the steady inner backbeat to issue soloes with spine -tingling freedom. Not to ignore his creative abilities-Nelson's guitar lines are perhaps AUDIO DECEMBER, 1975 91 Dept. AU -2-5500 35th N.E., Seattle, Wa. 98105 Check No. 55 on Reader Service Card Does Your AM Tuner Sound Like Quality FM? ytil)fO Our Dymek AM5 Does! AUDIO Custom designed Library Cases will protect your magazine copies. These files are rugged and made with a rich Kivar cover. Shipped postage paid. Prices: $7.50 each; 3 for $20; 6 for $37. Return the order form below with your payment. Please send me library cases. Prices: $7.50 each; 3 for $20; 6 for $37. My check or money order is enclosed. My Name Company Address City State Zip Mail to: Audio, 401 N. Broad Street Philadelphia, Pa. 19108 Allow four weeks for delivery. www.americanradiohistory.com AmericanRadioHistory.Com Solid state-FET-IC construction throughout Unusually low distortion-less than 1% Typical AM "noise and whistles" are 90% eliminated Ceramic filters provide remarkable selectivity 41.4,v sensitivity pulls in the distant stations Audio quality comparable to FM Factory direct-Money back guarantee. Lease plan and Master Charge available. Call or write for complete specs and performance details. Just $295.00 for FM quality AM reception. Call toll free today Nationwide 800/854-7769 California 800/472-7782 McKay Dymek Co. Dept H5 aleMP.O. Box 2100 Pomona, Calif. 91766 Check No. 54 on Reader Service Card controlled impedance bonus advantage of every Scott an extra loudspeaker system built since 1965. With controlled impedance, you are assured of compatibility between your speakers and your amplifier or receiver. Without controlled impedance, you can't be sure, for reasons we explain in our free brochure, "Controlled Impedance-Fact or Myth", which you may receive by circling reader service number or writing to us directly. Or visit your Scott dealer for a is I I demonstration of controlled impedance loudspeaker systems priced from $59.95 to $349.95. c3scorr I for the first American tour, commencing any moment now. haven't I been this excited over ® where innovation is a tradition H. H. Scott, Inc., 111 Powdermill Road, Maynard, MA 01754 Check No. 58 on Reader Service Card ZEROSTAT: FOR THE SCIENTIFIC TREATMENT OF STATIC Electrostatically attracted dust can cause surface noise and rapid wear of your records. Regular use of Zerostat helps ensure that your discs are kept in first class condition. And, since your record's surface static has been neutralized, no further dust will be attracted to it. Requires no power supply, batteries or refills. Lasts for at least 50,000 operations. The only device to neutralize by emitting both positive and negative ions. the most original heard this year, right up there with Zeppelin's Page, Queen's May, Cong's Hillage, and Beck's Beck. At last a guitar hero worth his weight in Les Pauls! But Bill Nelson is more than a onedimensional musician, for his songs are also outstanding. He's a bit of a ham, tending to describe in voluminous detail his experiences as a guitar player ("Well, I'm waiting in the wings with all the strings and things that help me make the music ...") or as a macho on the go ("Life is a love affair, all the girls declare it so ... they know am a gigolo ..."). Some may find it heavy-handed, but find it illuminating. The band keeps up with him every instant, though the album's bité comes about 90% from the mouth of Nelson. Simon Fox is the drummer and Charles Tumahai is the bass player, Roy Thomas Baker is the producer, and a good one. Bill Nelson has a strong set of pipes, and, girls, he's good-looking as well. just can't wait band in ages. Jon Tiven a Performance: A++ Sound: A Daryl Hall & John Oates RCA APL1-1144, stereo, $6.98 Hall & Oates hail from somewhere in Pennsylvania, and although I'm tempted to avoid the comparisons between their music and Todd Rundgren's, it's pretty near impossible. Their last album produced by Mr. R., was an embarassment to all parties concerned-combining the worst of Todd and the worst of this duo's talents. This time around, they sound almost exactly like they're living in the music of Todd's most frequently hailed album, Something Anything. They write in that style, the arrangements and production is very Toddish, and even the vocal nuances are straight out of Toddsville. This is not to knock the record, which like very much (especially side two), but it's just to put things in perspective. The music is quite pleasing to the ear, the lyrics are amusing, and the whole feel of the record is a good one. Hall & Oates both sing and write well, but find it difficult to understand how two people so obviously talented can live almost exclusively in another person's style. suppose if it's possible for Badfinger to live within the Beatles, and the Dolls to echo the Rolling Stones, then Hall & Oates aren't exactly the first to do what they're doing. But will the critics love I I I Distributed by Discwasher Inc. 909 University Ave., Columbia, Mo. 65201 Jon Tiven it? Sound: 92 B Performance: 8+ AUDIO DECEMBER, 1975 Jazz & Blues SPECTRO-ACOUSTICS Model 210 Graphic Equalizer provides 10 bands per channel of equal- ization allowing ± 15db boost or cut in each of the 10 audible octaves. An exclusive circuit utilizes "Gyrator" Synthesized Inductors which are almost totally immune to magnetic fields and current saturation. Any equalization setting can be made without exceeding the specified signal to noise ratio and distortion. * allUnique all circuitry IC Ella Fitzgerald and the Chick Webb Orchestra Joker SM 3613, mono, $4.98. Jazz fans who grew up in the 30s like to talk about the legendary battle of swing that took place the night of May 11, 1937 in Harlem's Savoy Ballroom between the Benny Goodman orchestra and the resident Chick Webb band. Goodman was then just arriving at the first high peak of his national fame and popularity, while the tiny, crippled drummer was the King of the 125th Street ballroom. By all accounts, Benny's band played as powerfully as ever that night, but the Webb crew blew the Goodmanites away with blazing, white-hot sets that drove the crowd wild. Aficionados tell how Webb finished off the session with a masterful drum solo that left Goodman and his drummer Gene Krupa shaking their heads, their jaws hanging in open admiration and amazement! For years Chick Webb's band has been revered by European jazz connoisseurs, and most Webb reissues have come from abroad. Ella Fitz - gerald and the Chick Webb Orchestra is on the Italian label Joker (reminiscent of the first pirated jazz issues of the 40s on Jolly Roger-are they trying to tell us something?). This is a splendid collection which showcases the Webb band's punchy, aggressive drive, and the recording has lively, vivid sound (considering they were transferred from shellac, 10 -in., 78 rpm discs). Such is the present day commercial potency of Ms. Fitzgerald (in her late teens then, and an immediate headliner with her hit A-Tisket, A-Tasket) that now, almost 40 years later she gets top billing over Webb on he cover. Though the LP is top-heavy with Ella's vocals, the tremendous drive and collective swing of the band come through on instrumentals Clap Hands, Here Comes Charlie, Spinnin' the Web, Harlem Congo, and Strictly Jive. The Edgar Sampson (of Stom pin' at the Savoy fame) arrangements are clean and spacious, leaving plenty of room for fiery soloists like trumpeters Taft Jordan and Bobby Stark. Hearing their surging, exuberant playing, one can almost see again those hundreds construction allows to be mounted on one easily removable circuit board which substantially reduces cost while increasing reliability and servicability. For more details see your local dealer or contact Spectro Acoustics, Inc. THD SPECIFICATIONS Less than 0.1% of RMS output 20Hz volt 1 - 20 KHz IMD S/N Less than 0.01% from ten volts to 100 millivolts composite output Noise and hum are over 105 db below full output $275.00 Spectro Acoustics Model 210 SPECTRO ACOUSTICS, INC. 1309 E. Spokane [509] 545-1829 Pasco, Washington 99301 AUDIO DECEMBER, 1975 93 www.americanradiohistory.com AmericanRadioHistory.Com Check No. 48 on Reader Service Card of high-stepping Savoy dancers, Lindying until the small hours every night. Home of Happy Feet, it truly was! John Lissner There's more to great sound than meets the ear. Sound: Skull Session: Oliver Nelson Musicians: Nelson, alto saxophone; Lonnie Liston Smith, electric and acoustic pianos; Mike Wofford, arp and piano; Chuck Domanico, bass; Dennis Budimire, Lee Ritenour; electric and acoustic guitars; Billy Green, When dust, dirt and static build up on your record, it can't possibly sound like it's supposed to sound. Groov-Kleen®is a specially designed component that removes dust and dirt, so you hear exactly what is and nothing else. recorded on your record Billy Perkins, Jerome Richardson, - Buddy Collette, Bud Shank, reeds; Buddy Childers, Bobby Bryant, Paul Hubinon, Oscar Brashear, trumpets and flugelhorns; Grover Mitchell, Richard Nash, Chancey Welsch, Maurice Spears, trombones; Vinny De Roas, Davis Alan Duke, French horns; Don Waldrop, tuba; Shelley Manne, Jimmy Gordon, drums; Willie Bobo, percussion. Songs: Skull Session, Reuben's Rondo, 125th Street and 7th Avenue, One for Duke, Dumpy Mama, Baja Bossa, In a Japanese Garden, Flight for Freedom. Flying Dutchman BDL 1-0825, stereo, An attractive chrome and steel armature, Groov-Kleen®mounts permanently on your unit. Its sable tracking brush and velvet roller lift dust and dirt out of record grooves and collect residue. All you have to do is sit and listen. And Groov-Kleen®also reduces stylus wear. There's a Groov-Kleen®for every record player, manual or automatic. What's more, Groov-Kleen®has height and balance adjustments to insure that it can be used on any record without causing speed variation. So see your record or audio dealer and find out about Groov-Kleen® Remember, when there's more to a record than you've been hearing, give a listen with Groov-Kleen® Bib® I?ib' I Vi i i Croov=Klccn® $6.98. Big bands have always possessed Accessories 155 Michael Drive, Syosset, N.Y. 11791 Check No. 4 on Reader Service Card 1Thin1oh CATALOG nd FM DIRECTORY Get all the newest and latest information on the new McIntosh Solid State equipment in the McIntosh catalog. In addition you will receive an FM station directory that covers all of North America. el 1S 11 p . i1. S2 6! !I 6 .ri..e Si -9 N g0 1 aIï MI a ill .i'4ihr.. NI ..,.x.1.1.i MX 113 FM/FM STEREO AM TUNER AND PREAMPLIFIER McIntosh Laboratory, Inc. East Side Station P.O. Box 96 Binghamton, N.Y. 13904 SEND Dept. TODAY! If you are in 1 NAME ADDRESS CITY STATE ZIP hurry for your catalog please send the coupon to McIntosh. For non rush service send the Reader Service Card to the magazine. a Check No. 27 on Reader Service Card Performance: A C - -i the greatest potential for harmonic, melodic, and rhythmic possibilities. When the jazz-rock group with added horn sections became popular in the late sixties, the big band moved into a new era, exploring things with results the smaller groups couldn't predict. Such was the success of Maynard Ferguson's MF Horn. Oliver Nelson has always been an advocate of the big band concept. His achievements are omnipresent in television, movies, jazz bands, etc., and in playing the sax. The premise for Skull Session was to see how melodic Nelson could make the electronic instruments sound. Electronics make instruments louder, and some people confused louder with better. But with Oliver Nelson the musical quality went in before the volume went up. The result is a set of strongly involving electronic and acoustic sounds, incorporating electronics with contemporary rhythm pulsations. Skull Session brought just this idea to reality. Mike Wofford on arp and Lonnie Liston Smith on electric piano pitted against the brass colorations produce electrifying results. The cut 125th and 7th Avenue is as crowded with full punchy ensembles and ear -grabbing solowork as this bustling intersection is with people. It 94 AUDIO DECEMBER, 1975 of much political and musical thinking, and Oliver Nelson has captured a veritable cross-section in this very funky composition. has been the site Best is the rhythm section, especially the interplay between Shelly Manne and percussionist Willie Bobo. There are a couple of swinging cuts which demonstrate how well balanced a set of rock electronics can be made to be. Reuben's Rondo is an augmented arrangement of a piece Nelson wrote in 1959. Shelley Manne is one of the most versatile drummers alive. His fills are museum pieces and his choice of cymbals is as tasty as the way he tunes his drum set. He is able to play any particular type of music and make it sound like it's the only type of music he plays. Other drummers should take a lesson from this brilliantly open-minded individual. One for Duke captures the sound of Duke Ellington's reed section in undercoating the melody with some bass clarinet. Then it begins to sound more like a thought from Thad Jones. Jerome Richardson leads the sax section and it takes on the sound of Jones' section during Richardson's tenure in New York. This arrangement has a much more modern sound than the post -bop Reuben's Rondo, as Mike Wofford comps on electric piano. Dumpy Mama is more funk. Richardson does extended time on the flute. Baja Bossa is a beautiful Latinesque sampler. Laurindo Almeida's acoustic guitar solo is a thoughtful introduction to In a Japanese Garden. It accurately reflects the serene atmosphere where ideas and feelings, as in music, are often understood more by a convincing look or quick glance than by verbal communications. Nelson's alto solo is an example of this superb articulation and phrasing. Skull Session is a worthwhile treat for big band enthusiasts, and it is a logical introduction to different kinds of good music for listeners who want to broaden their scope of music appreciation. Eric Henry Sound:B Performance: A Native Dancer: Wayne Shorter featuring Milton Nascimento Musicians: Shorter, tenor, soprano saxes, piano; Nascimento, vocals, acoustic guitar; Herbie Hancock, piano; Airto Moreira, percussion; Dave McDaniel, bass; Roberto Siova, percussion; Wagner Tiso, electric piano, organ, bass; Jay Graydon, bass; David Amaro, acoustic guitar. AUDIO DECEMBER, 1975 you cri considering en investment in sound rcorocuction, If Don't make a move until you hear the 3 new BOZAKS - For more than 25 years Bozak has been provid- ing discriminating music listeners with loudspeakers which have been recognized as representing the highest standards of integrity in sound reproduction. Now Bozak has applied its same principles of Model919Audio pushing the limits of the state of the art without compromising the laws of science two new electronic products and a new monitor type speaker for the home music systems of those who recognize and demand "the very best in music." design -to Signal Processing Center This mixer-preamplifier gives much of the flexibility found in commercial sound studios. With it you can mix and blend stereo sounds from records, tapes, tuners and microphones with differing input levels into a two -channel composite for recording or for listening. Model 929Audio Power Amplifier ultimate in an amplifier for the home music system, the Model 929 has nearly identical circuitry to Bozak's commercial Model CMA-2-150 which has The been selected for the most demanding applications theaters and auditoriums. Each of its two channels delivers 150 watts continuous minimum sine wave power into 8 ohms from 20 to 20,000 Hz at less than 0.2% total harmonic distortion. That is enough power for even the most importhose employing tant home music systems Bozak's Concert Grand speakers. in concert halls, - Monitor C Loudspeaker System Monitor C has been specifically designed to reproduce modern music, with its heavy emphasis on bass, with the greatest realism possible. You truly hear each note as it was played; Monitor C spells an end to "thump-thump" bass. Discotheques, as well as homes, are taking it to their hearts. magnificent audio system components at selected Bozak dealers. We'll gladly send you the name of one in your area. You can hear these 25ah' Bozak, Inc. Box 1166, Darien, Connecticut 06820 95 www.americanradiohistory.com AmericanRadioHistory.Com Songs: Ponta De Areia, Beauty and the Beast, Tarde, Miracle of the Fishes, Diana, From the Lonely Afternoons, Ana Maria, Lilia, Joanna's Theme. Columbia PC 33418, stereo, $6.98. Native Dancer boasts inspirational music from beginning to end. Short er's comments accurately summarize the musical results: "... only this combination of five Americans and four Brazilians could conceive and mold such an expressive life force contained within. I/ Although the music is restrained and relaxed in tempo and volume, it in no way lacks vital drive and intensity. Native Dancer possesses the power to move mountains and cut through icebergs without having to demonstrate explosive power. Shorter's piano playing makes a thoughtful addition to Diana, a composition to the daughter of Airto and Flora Purim. His playing mirrors the understatement which is the most elemental aspect of his sax work. Lilia is a conduit for an interesting 5/8 meter read the small print first. We're talking, of course, about the specs. Because they'll tell you right away just how good a mixer really is. And that's especially important when you've already got a quality recorder. Our Tapco 6200 has bass and treble controls on every channel. Complete stereo panning on every channel. Line outputs from every channel for quad recording. Line inputs on every channel for quad mixdown. 82 dB signal to noise ratio on balanced Low Z mike inputs. There's actually a lot more. Like the 6200's AutoPad automatic padding that virtually eliminates overload problems. And for complete recording studio capability at home, check the Tapco Graphic Equalizer and Reverberation System, too. The small print reads just as good. TAPCO Graphic Equalizer 289.00 4400 Reverberation 389.00 System .;;J 4**6 \i;. prano sax gently flows. Herbie Hancock's acoustic piano on Beauty and the Beast hints at what his repertoire may sound like in an acoustic setting. The cut is laid back but very funky. It's a catchy instrumental which you'll find yourself singing. Milton Nascimento is a very talented Brazilian guitarist and vocalist. Shorter said that he thought it unnec- Milton Nascimento because he thought everybody knew. Everybody who hears his essary to say who is unique performance will remember. When you're buying a mixer, 2200 undercurrent over which Shorter's so- 6200 Mixers From $349.00 TAPCO, 405 Howell Way, Edmonds, Washington 98020 (206) 775-4411 Ponta De Areia is a vocal carnival with apparent falsetto overdubbings surfacing beside Nascimento's leads. Most gratifying are Nascimento's quick and accurate range transpositions. Shorter's soprano brilliantly complements the vocals. A more mellow showcase is the magnificent ballad Tarde. Shorter is on tenor and Nascimento explores his own lower vocal range. Wagner Tiso builds a lilting harmonic foundation on organ. Tarde means suffering extendedly without asking forgiveness. The inside sleeve also explains the other titles. Miracle of the Fishes has an elusive melody throughout the tune which fades behind an electric piano codetta before we can grab it. Rhythmically a 6/8 Nanigo, it has quite a euphonious array of vocals. Shorter's articulations within lightning runs up and down the entire register of the saxes are flawless and his intonation is unwavering. Native Dancer is comparable to Chick Corea-Light as a Feather vintage. Both concepts take a light and airy approach to making music. Their music is relaxing yet stimulating, incorporating some provocative Brazilian elements. Light as a Feather is a musical milestone. Time will tell if Native Dancer stands in the same deep waters. The music has a hypnotic effect, transporting the listener to its tropic origins. Eric Henry Sound: A -/B+ Performance: A Jazz Funeral at New Orleans: George Lewis Olympic 7117, mono, $4.98. Live Concert: George Lewis & His Orchestra Saga 6921, mono, $6.95. New Orleans jazz is never better than when it is played by men who have lived with it all their lives; when trombone, trumpet and clarinet Check No. 49 on Reader Service Card 96 AUDIO DECEMBER, 1975 IC weave highly-charged counterpoint, and when the solos sail out of ensembles with increasing excitement. There are many moments like this in these collections, when the emotions and artistry of the New Orleans veterans communicate in an inspired man- ner. Clarinetist Lewis was part of the original Bunk Johnson band. Like other Crescent City revival groups, it was a collection of aging and out -of -practice Black and Creole musicians, ex stevedores and longshoremen, refurbished with instruments, (and, in Johnson's case, a new set of teeth) by DUO! liquid tone providing a fluency that is the cornerstone of the band's front line. The rhythm section is tremendous here with bassist "Slow Drag" Pavageau, drummer Joe Warkins, banjoist Lawrence Marrero, and pianist Alton Purnell playing with driving fervor that builds a rocking momentum as it rolls along furiously chorus after chorus. Both albums are well recorded, offering a crisp, monaural sound. Absolutely exhilarating music. John Lissner Sound: B+ Performance: A dedicated, white, middle-class fan/entrepreneurs. When the Johnson band hit New York in 1944 it received widespread media coverage. At its best it played with wonderful drive and spontaneity; it was jazz that got right down to the core. But at its worst, there were many embarrassing moments: grossly out -of -tune passages, botched ensembles, and defective tempos. After Johnson passed away in 1949 and George Lewis assumed leadership, things tightened up musically, and he successfully led the group until his death in the late 60s. These recordings contain selections culled from a 1953 Lewis concert. Some of the musicians involved, including the incredible octogenarian trombonist Jim Robinson, are still with us and playing with the Preservation Hall Jazz Band. Although the two albums, the budget Olympic and the British Saga duplicate each other on three tracks (When the Saints ..., Panama, and Burgundy St. Blues), they can be considered complementary and are both recommended. Saints is the key track, a remarkable eight -minute joy ride with inspired, solid ensembles full of color and movement, with Robinson playing a rough, savage trombone solo with tremendous vigor. Ice Cream, which appears only on the Olympic, really drives, with perfect swing created by piano, trombone, and the thumping, rhythmic thud of the banjo. The strong, surging exuberance of the players will lift you right out of your chair. Caledonia, which kicks off side two on the Saga disc, is another gem, a brassy, rollicking, boogie blues that starts off in a typically ragged manner, with trumpeter Avery "Kid" Howard barking the vocal, picking up strength on his horn, growling and blowing with the uninhibited energy of a much younger man. Lewis' expressive New Orleans clarinet is heard weaving in and out of ensembles with its AUDIO DECEMBER, 1975 97 Pyq GNOME er.t.tbie Illifl0-S5r 3q q5 *111"15 r ', you're into electronic music, PAIA's Pygmy Portable Amp and Gnome Micro-Synthesizer are a pair that's hard to beat. And now we offer them together, as a package, at a price that can't be beat $84.50 plus 10 lbs shipping If - -catalog #3741. DEMO LINE-Use Ma Bell's low night rates to get a one minute demo of PAIA Synthesizers. Our recording equipment also takes catalog requests, charge orders, etc. (405) 843-7396. - -FREE CATALOG- Dept II -A ``oL0 W. R 'Nr 1 Check No. Most effective cleaning system Easy ... Thorough ... Safe Cleans 'em all ... LP's, 45's, 78's Removes static... Leaves no residue Mo electricity ...You Spin & Clean Records Special concentrated Record Wash solution Gentle plush scrubbing pads get deep into grooves ... remove for easy cleaning Only $19.95, suggested list price. After years of research with all types of record cleaning gadgets, gizmos and gimmicks, Fidelitone came up with a simple, direct solution ... the Record Washer! Now you can wash your records quickly and easily with this unique Spin & Clean system. Gets out dirt deep down in the record groove... gives you maximum performance from your old records. Comes complete with special cloth and enough Fidelitone Record Wash Concentrate to wash up to 1,000 records! Wilshire ß 31 on Reader Service Card J. E. SUGDEN & CO. LTD. AUDIO EQUIPMENT OF BRITISH DESIGN «mace AMPLIFIERS AND TUNERS AS WELL AS LABORATORY MEASURING INSTRUMENTS by the QUALITY MINDED for the QUALITY MINDED WHY SETTLE FOR ANYTHING ELSE? FOR INFORMATION WRITE: FIDELITONE 207 N. Woodwork Lane THE TOUCH OF MAGIC in Phonograph Needles, Cartridges, Record Care. and Audio Accessories Palatine. IL 60067 Check No. 14 on Reader Service Card AUDIO IMPORTS P.O. BOX 27345 INDIANAPOLIS, IND. 46227 Check No. á OY,Ivho/1CfY10K7 /b 2 on Reader Service Card Advertising Index PAGE ADVERTISER Ace Audio Preamplifiers Check No. 56 on Reader Service Card 111 21 Acoustic Research Loudspeakers 37 Styli Check No. on Reader Service Card 1 PAGE ADVERTISER 14, 15 Rectilinear Entertainment Products Stereo Receivers Check No. 17 on Reader Service Card 41 Harman-Kardon Hi -F Components Check No. 18 on Reader Service Card 10,11 GTE Sylvania - Write Direct to Advertiser Astatic ADVERTISER Garrard (Plessey) Turntables Check No. 16 on Reader Service Card Audio Imports Audio Equipment Check No. 2 on Reader Service Card 97 Audio Technica Cartridges 90 Institute of Audio Research 12 Education Check No. 20 on Reader Service Card Jennings Research Loudspeakers Check No. 25 on Reader Service Card BGW Systems Amplifiers Check No. 4 Infinity Systems 13 Bose Corporation Speakers Jensen Sound Labs Bozak Hi-Fi Components 95 Lux Audio Hi-Fi Components Write Direct to Advertiser Braun Speakers 49 Magnavox Write Direct to Advertiser Capitol Magnetics Recording tapes Check No. 5 on Reader Service Card C/M Laboratories 105 Mantis Research Labs Hi-Fi Components Check No. 24 on Reader Service Card 82 20, 83 Marantz Hi-Fi Components Check No. 9 on Reader Service Card 112 Samples Write Direct to Advertiser Discwasher Record Cleaning Device 2, 92 Write Direct to Advertiser Dual (United Audio) Hi-Fi Components Check No. 11 on Reader Service Card 8 7 45 Rocelco Loudspeakers Check No. 10 on Reader Service Card 43 6 Hi-Fi Components Check No. 41 on Reader Service Card 58, 59 Hi-Fi Components Check No. 42 on Reader Service Card 109 Saxitone Cassettes 26 106 Cover Ill 87 94 Tuners & Preamps Check No. 27 on Reader Service Card McKay-Dymek AM Tuners and Antennas Check No. 54 on Reader Service Card 91 MXR Innovations Hi-Fi Components Check No. 28 on Reader Service Card 57 Onkyo 110 Teledapter Write Direct to Advertiser Sansui 27 Check No. 26 on Reader Service Card Mc Intosh Record Cleaning Device Check No. 40 on Reader Service Card SAE Cassettes 85 Discount Music Club 51 Write Direct to Advertiser Maxell Microphones Check No. 39 on Reader Service Card Rhoades 36 Speakers Hi-Fi Components Check No. 7 on Reader Service Card DBX 4, 5 Check No. 22 on Reader Service Card Hi-Fi Components Check No. 8 on Reader Service Card Crown International Hi-Fi Components Check No. 6 on Reader Service Card Magnepan Hi-Fi Components 25, 89, 94 Revox Hi-Fi Components Write Direct to Advertiser i -Fi Components Check No. 23 on Reader Service Card Write Direct to Advertiser 89 Check No. 38 on Reader Service Card Hi-Fi Components Check No. 21 on Reader Service Card Write Direct to Advertiser PAGE Speakers Speaker Systems Check No. 19 on Reader Service Card on Reader Service Card J 103 Receivers, Amplifiers, & Tuners Check No. 30 on Reader Service Card Write Direct to Advertiser Schwann Record & Tape Guide 107 Scott Hi-Fi Components Check No. 58 on Reader Service Card 92 Write Direct to Advertiser 31 Shure Hi-Fi Components Check No. 43 on Reader Service Card Sonic Research Cartridges Check No. 46 on Reader Service Card 39 Sony Corp 61 Hi-Fi Components Check No. 13 on Reader Service Card Soundcraftsmen Hi-Fi Components Check No. 47 on Reader Service Card 86 Speakerlab Speaker System Kits 24 Write Direct to Advertiser Spectro-Acoustics Hi-Fi Components Check No. 48 on Reader Service Card 93 97 Superscope Hi-Fi Components Write Direct to Advertiser Phase Linear Amps & Preamps Check No. 32 on Reader Service Card Tapco Hi-Fi Components Check No. 49 on Reader Service Card 96 55 TDK Cassettes 84 Pickering Cartridges Check No. 33 on Reader Service Card 23 3 Pioneer Turntables Check No. 34 on Reader Service Card Cover II Fidelitone Hi-Fi Components Check No. 14 on Reader Service Card 97 Primo Co Hi-Fi Components Check No. 35 on Reader Service Card 106 Fuji Hi-Fi Components Check No. 15 on Reader Service Card 35 Radio Shack Hi-Fi Components Check No. 36 on Reader Service Card 83,90 Dynaco Hi-Fi Components Write Direct to Advertiser 33 Marketing Hi-Fi Components Write Direct to Advertiser 88 Elpa Empire Scientific Corp Cartridges Check No. 12 PAIA 29 on Reader Service Card E.S.S. Hi-Fi Components Check No. 13 on Reader Service Card Amplifiers & Synthesizers Check No. 31 on Reader Service Card Hi-Fi Components Check No. 37 on Reader Service Card 98 9 Check No. 50 on Reader Service Card 52, 53 TEAC Cassette Deck Check No. 51 on Reader Service Card Technics Hi-Fi Components Check No. 52 on Reader Service Card Cover IV 108 Tripod Hi-Fi Components Write Direct to Advertiser Yamaha Audio Hi-Fi Components 19 Check No. 53 on Reader Service Card AUDIO DECEMBER, 1975 /What's New in Audio1 J Bozak Model 929 Preamplifier This Audio Signal Processing Center includes a phono input, microphone input, and choice of tuner, AUX, or either of two tape inputs. All preamplifier stages are on plug-in modules. A Mike Pan control permits shifting the apparent position of a microphone anywhere from extreme right to extreme left. The continuously variable Stereo Blend slide control goes from mono to stereo, and may even be expanded to an "extra -wide" dimension labelled Stereo +. The mode selector includes Mono, Stereo, Reverse Stereo, Stereo Blend, and Reverse Blend. Two tape monitor circuits are provided. A Cue Output Selector permits monitoring Phono, either Tape Monitor, Program, or Main Output. Distortion is less than 0.1% When you hear the incredible sound... Inovonics Recorder Electronics These single -channel tape recorder electronics include play, record, and bias/erase circuitry in a rack -mount panel 31/2 -in. high, made to plug directly into Ampex 300, 350, and 351 transports, but can be readily adapted to other tape mechanisms. Switching -electronic, eliminating mechanipermitting remote control. Reproduce circuitry is phase corrected. The regulated power supply and plug-in circuit cards are included. Record amplifier distortion measures less than 0.1% at operating is all cal switching noise and level, less than 0.2% at 25 dB above operating level. The 360 circuitry is priced at $645.00. Sync reproduce op- tional at $60.00. Check No. 70 on Reader Service Card Hirschmann Antenna/Booster 111 20 to 20,000 Hz. at 10 V into 200 ohms. The 929 is 7 -in. H, x 17-3/4 in. W, x 10-3/4 in. D. It weighs 21 pounds and is priced, w/o optional walnut cabinet, at $797. from when you touch the sense ive, responsive controls... i and when you see the beautiful craftsman- ship... /NM Check No. 72 on Reader Service Card Society of Audio Consultants A new Consumer Associate member category is opening in the Society of Audio Consultants (SAC) which presently has more than 3,000 professional Certified Audio Consultant Members. For the charter membership of $7.50 before January 15, 1976 members will receive the monthly newsletter, audio career information, free advertising privilege in SAC's Audio Flea Market, special rental privileges on home study courses and exclusive premiums from equipment manufacturers. Annual membership fee is $10. Check No. 74 on Reader Service Card AUDIO The Hitronic electronic car aerial miniature amplifier built into the has a base of the unit, which will amplify signals up to a level double the original. There are seven click -stop aerial lengths, one of which will be suitable for any signal field strength, and an eighth or retracted position for car washes. Operating voltage is either 6 or 12 V, and current consumption is about 7 mA. The base can be mounted at any angle from horizontal to vertical through use of the template supplied. Price: $46.08. Check No. 71 on Reader Service Card DECEMBER, 1975 103 www.americanradiohistory.com AmericanRadioHistory.Com you'll want o own one. Onkyo offers a full line of highly rated stereo receivers, amplifiers and tuners; the world's 1st fully automatic 4 -ch receiver; 2/way & 3/way speaker systems ... all in a broad price range. See your dealer. O Ai IKYO Onkyo U.S.A. Corporation 25-19 43rd Ave. Long Island City, N.Y. 11101 935 5ivert Drive, Wood Dale, Ill. 60191 Check No. 30 on Reader Service Card Canby's Capsules J Edward Tatnall Canby Judith Biegen, Frederica von Stade. (Solos and Duets for soprano). Charles Wadsworth, piano. Columbia M 33307, stereo, $6.98. Two glorious all-American star voices, (despite the names) in solos and duets with piano, ranging from Scarlatti, Mozart, Schubert, through Brahms, Chausson, Saint-Saens. Only one problem: all the music is "chamber" type, closeup room music, and the recording is the same-but the ladies let loose like the Met. TOO LOUD!! Fine sound but very out of style. When will American pros learn to sing softly and well? Why so powerhouse?? Simple Gifts. The Metropolitan Opera Madrigal Singers. (Met. Opera Guild.) Advent 50102, stereo, $6.98. (878 Clarence Rd., Cleveland, Ohio 44121) Six Hindustani -A Panorama of North Indian Music. Vanguard Everyman SRV 73010, stereo, $3.89. -A Karnatic Panorama of South Indian Music. Vanguard Everyman SRV 73011, stereo, $3.89. Janet Baker - Mozart, Haydn, Engl. Chamber Orch., Leppard. Philips 6500 660, stereo, $7.98. Janet Baker - Handel. Engl. Chamber Orch., Leppard. Philips 6500 523, stereo, $7.98. The Artistry of Janet Baker (Holst, Finzi). With Wilfred Brown, ten. Engl. Chamb. Orch. Imogen Holst. Everest 3365, QS, $4.98. Elgar: Sea Pictures. Mahler: Five Songs from Ruckert. Janet Baker; London Symph., New Philharmonia, Barbirolli. Angel S 367%, stereo, $6.98. younger Met members in an unexpected operation-madrigals, songs together, even church motets. They do remarkably well, considering, and the sopranos know how to sing softly. But the ensemble, well coached, still sounds faintly like that Sextet in Lucia. No great blend. Opera lovers will be charmed, rightly, but choral and madrigal people will be unamused. Far -Eastern music is rapidly making its way into Western cultures and these two BBC -derived discs, deliberately designed to bring unusual instrumental and vocal Indian music to records (radio?), are beautifully performed, superbly recorded, well annotated, evidently taken down locally in India. Exotic sounds-musical glasses, unusual strings, drums, a sort of "jews harp," plus some singing. You could well start your Oriental Collection right here, and the price is decidedly right. A great vocal musician in recent perspective-she began as a pure British -type soprano, has now turned more international and operatic, still with perfect control and accurate muscianship. The Mozart/Haydn, a brace of mostly unusual arias and songs, is top rank. Her Handel, a choice of highly florid and difficult items, is a bit heavy -voiced (and close -recorded) for Handel, but still remarkable. The Everest Artistry is a reissue, one side Holst, the other Britisher Finzi-Holst is massively introspective and long, for U.S. ears, Finzi is more open, straight Romantic; she shares it with tenor Brown. Best of all these (and there are others) is the Elgar/Mahler of c. 1970, when Baker still sang pure British. Lovely, un -pompous Elgar songs, plus a side of Mahler. A dedicated performance. The Art of the Viola da Gamba, vol. 2 Marin Marais. Eva Heinitz; Malcolm Hamilton, harpsicordists. Delos DEL 25403, stereo, $6.98. The grand lady of the gamba summing up her longtime art in this series. By now she sounds a trace old fashioned, playing cello-like (with some vibrato) but she's always authoritative and musical. Marin Marais, the gamba composer, writes somewhat didactic French Baroque suites. Eva Nordfelt plays Swedish Baroque Harpsichord Sonatas (Roman, Agrell). Orion ORS 74157, stereo, $6.98. This forceful Swede, not yet 30, plays in the Landowska tradition, strongly, heavily registered and dramatic. Stockholm's Baroque sounds much like other late Baroque; both Roman and Agrell are younger than Bach, edging on into early Rococco or "galant" style. Interesting. Domenico Scarlatti Sonatas for Harpsichord, vols. 1, 2. Kenneth Cooper. Vanguard VSD 71201/2, stereo, $6.98 The jaunty color cover, Cooper in an outrageously ruffled and printed mod shirt with two fingers in the air, sets the tone for these amiable and generally excellent Scarlatti renderings. Get 'em by all means! ea. 104 AUDIO DECEMBER, 1975 Satie for Two. Peter Kraus, Mark Bird, guitars. Orion ORS 74163, stereo, $6.98. Two young classical guitarists here take on that old French music -devil, Satie, whose many small piano works slyly dug at the foundations of tottering Romanticism back in the late 19th C. Satie's satire was in the deflated titles-Dried Embroyos, Cold Pieces, etc.-but also in artful musical simplicity, full of titillating "mistakes." These qualities come over well on the two guitars, though the boys are perhaps a bit too earnest. (Satie was never earnest! A total, gadfly. Outwardly, anyhow.) Brahms: Complete Piano Quartets. Beaux Arts Trio (Cohen, Greenhouse, Pressler) and Walter Trampler, viola. Philips 6747 068, 3 discs, stereo, $23.96. If you are in Ivan Rebroff. 25 Greatest Russian Melodies. With balalaika ens. Vanguard Twofer VSD 67/68, 2 discs, stereo, $6.98. Acoustic Research, Inc. Demonstra1: The Sound of Musical Instruments. (10 American Drive, Norwood, MA 02062) $5.00 tion Record. Vol. ('SECRETS a Brahms mood, here's a fine supplement to the big orchestral pieces-three big works for three strings and piano, gorgeously recorded and played by an American -based, super -pro foursome (two born in Europe), impeccably tuned to the European tradition. The polish and sheen is purely American, the styling good continental. The pianist, rightly, is the powerhouse here-Manahem Pressler, one of the best. The others play too blandly for my taste, but he keeps things moving. Here's that man again-huge, cavernous Russian basso who suddenly becomes a tenor, then a torchy contralto, and a soprano, more or less. Assuming it really is all him. Even some male -female duets in octaves. Overdub? Can't be sure these days! Anyhow, he gets all the label credits. Russian pop/folk style, big orch. with balalaikas, some no -voice bands for contrast. Easy listening, and now all you'll need is Yma the Sumac-you'll have heard Everything. (But he's much better.) Mostly classical excerpts, out of Spain and Discos Ensayo. This-for a demo-is musically more responsible than most. Only a few items are faded out in mid note or mid -movement, and most are reasonably long, ranging from Bach to jazz, via Mozart, Stravinsky, Britten, Albeniz, and so on. Hi-fi annotations on each piece-how to listen and judge your equipment. Some of it mildly fatuous, some pretty good. How about: "Who would deny that the human voice is the most expressive of all instruments?" Not me! FROM THE AUDIO FILE ADVICE FROM: Jay Ranellucci, recording engineer, Capitol Records, Inc. PROBLEM: Do you record electric guitars and end up with static? Do your country western tapes crackle and pop like a campfire? The problem could be dropouts caused by tape creases, dust, debris or flaking iron oxide coating. RECORDING TIP: Dropouts can be more of a problem with cassette tape because of its slow playback speed. One dust clump will obscure more signal at 1% ips than at 15 ips. To eliminate the problem, use special care selecting, handling and storing your cassette tapes. TAPE TIP: Record on premium tape that has a heavy duty binder to prevent oxide flaking. Use tape treated with conductive coating to prevent static from building up in low humidity. (Static attracts dust and debris.) Unlike most tapes, The Music Tape conductive coating is on the underside, so as not to diminish the amount of signal -storing oxide on the recording side. Thus dropouts are prevented without sacrificing recording quality. When you record music, record on Le CAPITOL MAGNETIC PRODUCTS A DIVISION OF CAPITOL RECORDS. INC. A MEMBER OF THE LOS ANGELES. CALIFORNIA 90078 the music tape TMJ EMI GROUP TM OE EMI LIMITED Check No. cassette 5 cartridge open reel on Reader Service Card BY CAPITOL J Classified AUDIO RESEARCH MAGNEPLANARS and Electronics, ESS. Infinity, Ohm, DahlquisL EPI, Audionics, Radford, Crown, Citation. BGW, Transcriptor, Linn-Sondek Keith Monks, ERA, Connoisseur, SME. Supex, Decca, Grace, Sony, Spectrum Scanning Tuner, Epicure Amplifier, Marantz 500, DBX, ADC. Nakamichi, B&O, Tandberg, Celestion, Marc Levinson, Stax, Dayton -Wright others. THE GRAMOPHONE LTD., 757 Asp St., Norman, Okla. 73069. 405-364-9477. DON'T LET VOLTAGE TRANSIENTS ZAP YOUR HI-FI. Solid State Equipment Protector. Plugs into outlet. Check or money order S6.95. Kopp Sales & Service, 1650 William St., Buffalo 14206. Free brochure -send SASE. RECORDING TAPE CLOSEOUT: Dozen reels 2400', $12.00. Dozen 1200', $8.00. 24 reels 900', $6.00. 24 600', $5.00. Postpaid Guaranteed. Mitchell, Box 132A, Flushing, N.Y. ANTI-SKATING fix AR TURNTABLES!! Proven counterweight design of nickel steel & aluminum construction. Install yourself in minutes. $7.00 postpaid. (Dealer inquiries invited.) AUDIO INNOVATIONAL PRODUCTS, P.O. Box 137, Ballardvale Station, Andover, Mass. 01810. - OTHER MOVING COIL CARTORTOFON SUPEX RIDGE OWNERS; Send for free literature on our MicroHuntington at $99.95. performance Preamp Superb Electronics, Box 2009-A. Huntington, Conn. 06484 ELECTRONIC CROSSOVERS-ALL TYPES. Updated definitive booklet describes applications; how to improve speaker systems: $7.50 postpaid, credited to first purchase. Huntington Electronics, Box 2009-A, Huntington, Conn. 06484. LOWEST DISCOUNT PRICES ANYWHERE on audio equipment. All major brands discounted. Write for quotes. K&L 02172. Sound Services. 75 N. Beacon St., Watertown, Mass. DIAMOND NEEDLES and Stereo Cartridges at Discount 11367. ONE STOP for all your professional audio requirements. Bottom line oriented. F.T.C. Brewer Company, P.O. Box 8057, DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES WAREHOUSE OF SARASOTA, 6564 GATEWAY AVENUE, SARASOTA, FLORIDA 33581. BUILD YOUR OWN SPEAKERS AND SAVE UP TO 50%. You can assemble your own high quality, multi -element stereo speakers in a few hours and save up to half the cost of comparable speakers. Send for our free 32 -page catalog of speaker kits, raw speakers and accessories. SPEAKERLAB, Dept. A2, 5500 -35th N.E., Seattle, WA 98105. OPERA TAPES. Historical performances of past 40 years. Unbelievable treasures and rarities. ALSO LP RECORDS. Free catalog. Ed Rosen, 66-33 Saunders St., Rego Park, N.Y. Crown, Dahlquist, Dyna, Epicure, Infinity. Philips. SAE, SME, Stax, TEAC, Technics. Thorens and many more (203) 348- 3551 (Closed Mondays). GRAPHIC EQUALIZER PLANS: Novel circuit very effective/inexpensive, requires no inductors. Ten knobs (octave bands) compensate your Hi-Fi/Tape providing better listening. Complete plans rushed only $3.49. GREEN BANK SCIENTIFIC, Box 100C, Green Bank, WVa. 24944. COMPETENCE IN AUDIO SINCE 1928! Qualified service, custom installations Klipsch, Sequerra, SAE, McIntosh. Levinson, SME, Ortofon, Fidelity Research,Tandberg. We buy and sell quality used gear. THE MUSIC BOX, INC. 58 Central Street, Wellesley, Mass. 02181. (617) 235-5100. SIGHT & SOUND LTD. Catering to the audiophile who desires the absolute in sound, equipment, service and professionalism. OUR LINES DahlAmpzilla, ADS/Braun, AKG. Bá0, Beyer, Bose, Crown, quist, DBX, Linn Sondek/MAL, Magnepan, McIntosh. Micro Acoustics, Ortofen. Revox, Soundcraftsman, Tandberg, Yamaha. - OUR STAFF all devoted auEngineers, physicists, musicians, teachers diophiles dedicated to providing the epitome in experience, patience and service. OUR LOCATION Campus Hills Shopping Center, Five miles northeast of Bel Air, Maryland 21014 on Route 22. Phone 1-301-838-2100. our suppliers include...dahlquist ampzilla thaedra b & o allison yamaha citation sonus nakamichi advent ads technics tandberg phase linear stax denon tripod 219 main street northampton THE MONEY SAVER! Write STEREO SPECTRUM, Box 33139. tripod audio offers you advice on & demonstrations of the finest equipment available. our emphasis is on giving you the best sound/dollar value we can. 11374. prices for Shure, Pickering, Stanton, Empire, Grado and ADC. A. Box Send for free catalog. LYLE CARTRIDGES, Dept. 69 Kensington Station, Brooklyn, New York 11218. FL massachusetts Pensacola. Florida 32505. WESTCHESTER AND FAIRFIELD COUNTY AUDIOPHILES TAKE NOTE! THE AUDIOPHILE. 231 BEDFORD STREET, STANFORD, CONN. specializes in equipment for the connoisseur. Ampzilla, Koss Model One, ADC, Citation, 1818, Miami Beach, FOR SALE FOR SALE FOR SALE - J CONNECTICUT: Yamaha, Celestion, IMF, Infinity, Braun, Re vox, Stellavox, Thorens, ESS, Supex, BGW. Will ship prepaid. AUDIOCOM, 177 Sound Beach Avenue, Old Greenwich, Conn. 06870. (203) 637-3621. STEREO TIMER AND ELECTRONIC DIGITAL CLOCK. P.C. Board with instructions $9.95. Kit with box $99.95. Assembled unit $149.95. Wake up and fall asleep to strains of your favorite AM/FM, record, or tape. This product will be an attractive addition to your stereo audio (413) 584-6498 DYNACO-A-R. transistors, repairs -boards-& units, speaker service. Send for prices & details: BEAR ELECTRONICS, 177R Hillcrest Road. Mt. Vernon, N.Y. 10552. GIMMICK! JBL, Manants, Pioneer discounted 60%? Amazing details FREE. John Peterson, Box 8014A. Canton, NO Ohio 44711 AUDIO BREAKTHROUGHS "We're closing the gap on perfection" Long Island's finest audio dealer. The incredible Lux M-6000 now you can hear what a $3.000 amplifier sounds like' Switches up to 1200 watts. Cosmos Electronics, Dept. A3 P.D. Box 33278, Seattle, Wash. 98133. the original Transcriptors turntable with new fluid arm; complete selection of ultra -fidelity records: Sheffield, Levinson. Fulton, Jonas Miller and more! Just arrived; the new elliptical Decca Mk V, Audiocraft and Grace damped tonearms, Satin "ultimate" cartridge, plus Paoli tube amplifier, Magneplanar, Linn Sondek, Lux turntable, VIDEO EQUIPMENT -LOW PRICES PANASONIC -cameras, monitors, vtrs B&W, KEF speakers and drivers. Yamaha (CT -7000, B-1 and NS -1000M!), Supex, M&K super woofer, IAD ultra-low distortion dynamic range expander! Levinson, new Polk, equipment. RCA -cameras (low light), monitors GYYR-time lapse vrt Many accessories; new vidicons Write or call your needs. ELECTRONIC EYE 9044 Eldora Drive Cincinnati, Ohio, 45236 (513) 891-9044 SAVE TIME AND MONEY! We have 15 years experience selling over 60 major brands. Save up to 50% off. We get the best deals from the manufacturers you get the best deals from us! Call now (212) 338-8555 or write, S.C.A. Dept. AM. 2122 Utica Ave. Brooklyn New York 11234. See damped IMF and the list goes on...AUDIO BREAKTHROUGHS. 1681 Northern Blvd., Manhasset, N.Y. 11030. (516) 627-7333. DONT PAY THE HIGH MAIL ORDER PRICES. THIEVES WAREHOUSE OF FT. WALTON BEACH, 652-D BEAL PARKWAY, N.W., FT. WALTON BEACH, FLORIDA 32548 - Custom designed; fully tested; guaranteed quality. Free brochure. Write: Networks; Box 458; Placentia, CROSSOVERS Calif. 92670. -T -M -C - DK AX E L L -MEMOREX AP IT O L AMPEX. Blank tape. Lowest Prices S & P Enterprises, Box 101, Elk Grove Village, III. 60007. SCOTCH Rates: J5t per word per insertion for noncommercial advertisements; 60é per word for commercial advertisements. Frequency discounts as follows: 3 times, less 10°/n; 6 times, less 15%; 12 times, less 20%. Closing date is the FIRST of the second month preceding the date of issue. Payment must accompany all orders. Use the handy self-addressed, postage paid card at the back of this issue. When replying to Audio box number ads, send letters c/o Audio, 134 North 13th Street, Philadelphia, Pa. 19107. For more information about classified advertising, circle Reader Service Card #135. 108 AUDIO DECEMBER, 1975 FOR SALE ATTENTION: LATIN AMERICAN AUDIOPHILES ATTENTION: VACATIONERS VISITING THE MIAMI AREA ATTENTION: RESIDENTS OF SOUTH FLORIDA CASSETTES Plain white cassette labels. Norelco cassette cleaners, famous brand cassettes. Send for open reel and cassette discount catalog. 1-9 10-99 100 1000 10M .01 .006 Cassette Labels .02 .015 .55 .50 .45 .65 .60 Norelco Cassette Cleaner .75 .e0 10" Metal, NAB, Used Reel 1.00 1.00 .90 .35 .30 10" Fiberglass used slb" Hole .50 .50 .40 2.72 2.55 2.44 Scotch Cassette SC9OHE 'Buy 2, SC9OHE, get 1 free. Plus Postage by Weight and Zone. Minimum Order 95.00 OPEN REEL STEREO TAPE BUYERS! At last! An open reel catalog, including titles, songs, etc. of 95 long play, 2-3 hour albums by American Airlines or Ampex 4 track stereo we will also mail you a 140 -page Harrison tapes. Send $1.00 this $1.00 is you'll get both for $1.00 stereo tape guide refundable on your first $10.00 purchase of open reel stereo tapes at our 30% discount. -and -so Win Got the "spirt" The Prices And -and the redress To FOR SALE FOR SALE Prove It Saxitone's Bicentennial Tape Shoppe 1776 Columbia Rd., N.W., Wash. D.C. 20009 ATTENTION,,, LUCKY OWNERS OF DYNA STEREO 70 INFINITY 2000A art stereo. Some of our products include: - ELECTROENCEPHALOPHONE: brainwave monitor, Professional biofeedback instruments. J&J 8102-A, Bainbridge, WA. 98110. 10Yr- RECORDER SPECIALISTS: Fresh new Scotch L/N 3600 ft. on new 'la" NAB metal reels five for $35.00. New CENTRAL NEW YORK HI-FI ENTHUSIASTS -Britain's fidemonstration -THE IMF STUDIO as Marantz, Pioneer, Revox, Beyer, Epicure (3 lines), Thorens. Ortolan, XLM, Discwasher ... THE SOUND SHOP, 96 Seneca Street, Geneva, N.Y. 14456 (315) nest loudspeakers AND ALS40-as well on - Monitor, IMF Studio 1118, Co. - UltimoDV38/20A, Denon PICKUPS AND TONEARMS 103-S, Satin M15 Conic, Supex 900 and 901, Ortofon SL 15E Moving Coil Pickups, SME, Audiocraft. KMAL, Grace 707 Tonearms, Dayton Wright 535 Infranoise Cartridge Pre -pre amp, Denon Transformers, Ortolan Transformers, and Hoff- RECORDINGS - A range of selected British, French, and German pressings. Also, the Fulton and Sheffield discs. All of the above products are in stock and on demonstration in our 1100 sq. ft. showroom. SOUND COMPONENTS, INC. 2710 POUNCE DE LEON BLVD. CORAL GABLES, FLORIDA 33134 Telephone: 305-446-1659 TWX: 810-848-7627 Superb Products For The Discriminating Audiophile and Music Lover. - DOUS DISCOUNTS. DYNACO COMPONENTS AT TREMEN- Write En-Jav Sales. Hornepayne, Ontario. TUNED ROCK P.A.'s. Customized high intensity touring/permanent installation sound systems, including narrow CALIFORNIA'S UNIQUE AUDIO SHOP proudly presents: at your ems), room design/measurement/treatment, <15% articulation loss of consonants, 1000's of customized professional products including ... fiberglass horns, consoles, comp/rims/peak limiters, 18db continuously variable electronic crossovers, digital/acoustic delays; omnipressors, pha- THE FIRST (19621 and most durable of the "underground" subscriber -supported audio publications, STEREOPHILE has proven itself the most reliable source of information available to the perfectionist who can hear differences between the top amplifiers, pickups. etc. There are good reasons why the latecomers have modeled themselves after STEREOPHILE. To learn some of them, write for our free blurb sheet or send $7 for 4 issues of the real thing. Address to STEREOPHILE, Box 49. Elwyn, Pa. 19063 CYBERACOUSTIC LABS presents the new RTR RECT DRIVE ELECTROSTATIC TRANSDUCER DR -1 DI- SYSTEM!L DRIVEN by its own internal servo -feedback amplifier! sors, reverb, echo, doubling/tripling effects. P.A. noise reduc- tion, piezo transducers, frequency shifters from ... J.B.L./Altec Pro, Tascam, U.R.E.I., Eventide, Gately, Studer. Beyer, Crown, Community Light/Sound, Mom's Audio, McIntosh, Bozak, Allen Health. Gauss, Cetec, Scully, Multitrack, etc., etc. All shipped prepaid/Insured. Music & Sound Ltd. 11'h Old York Rd., Willow Grove. Pa 19090 (215) 6599251. 1-215-667-3048 DYNACO RACK MOUNTS for pre -amps. tuners, integrated amps. 524.95 postpaid, $22.50, three or more. AUDIO BY ZIMET, 1038 Northern Blvd., Roslyn, N.Y. 11576 (516) 621- Write for quotes on all medium and many High End lines. We need campus reps and people seriously interested in hi-fi to properly demonstrate a fantastic loudspeaker line. Liberal compensation for qualified individuals. Write: Audio P.O. Box 36 Solsberry, Indiana 47459, or call (812) 825-9750 or (812) 332-4252. AUDIO UTAH'S OLDEST, FINEST AUDIO SPECIALISTS McIntosh Levinson Infinity Bozak Servo Statik IA JBL Pioneer DSP Amp B&O Supex Stanton Yamaha Tandberg AKG Nakamichi DBX --- WINTERTON'S AUDIO 2164 Highland Drive Salt Lake Provo Price 0138 UNIQUE MODIFICATIONS ENGINEERED SPECIFICALLY THESE COMPONENTS. NOW YOU CAN GREATLY IM- PROVE THE SOUND QUALITY TO "ULTRA DEFINITION" PRICED FROM $25.00 TO $170.00, OUR MODI- FICATIONS OFFER VAST AUDIBLE IMPROVEMENTS AT REASONABLE COST. INFORMATION CONTACT: DKL LABORATORY, INCORPORATED BOX 883 SEVERNA PARK. MARYLAND 21146 OR CALL: (301) 588-6257 MONDAY, WEDNESDAY. THURSDAY, SATURDAY 2-8 PM AUDIO RESEARCH -electronics and speakers BOW -power amplifiers DBX-noise reduction systems, dynamic range enhancers "HAND -TUNED" DECCA MKV-cartridges DYNACO-tube electronics FULTON-regular and MODULAR speakers HK CITATION -amps, tuners IMF -"MONITOR -ORIENTED" speakers, kits, sub -woofers LIN N -S O ND EK-turntables MAGNEPAN-speakers M & K-sub -woofers, matrix systems PAOLI-tube amplifiers RABCO-turntables RTR-electrostatic speakers SOUNDCRAFTSMEN-pre-amps. equalizers STAX-electrostatic headphones "SUPER SHURE" SME-tonearms TANNOY-turntables, speakers AND SCORES MORE. - WASHINGTON D.C., MARYLAND, VIRGINIA AREA RESIDENTS TAKE NOTE YOUR "STATE-OF-THE-ART" DEALER IS: DKL SOUND LAB 943 BONIFANT SILVER SPRING, MARYLAND 20910 Hours: MONDAY, WEDNESDAY, THURSDAY, DEALERS!! CONSUMERS!! MORE musical than any tube or fet system ever devised! ITS uncanny realism is totally unequaled by any other electrostatic system, including headphones! THE first true non -directional (360') electrostatic system! GATHER your most revealing records or master tapes and call for an appointment today! Cyberacoustics by Barclay Philadelphia's Exclusive RTR Distributor 503 Haverford Ave.. Narberth. Pa. 19072 FOR WE SPECIALIZE IN ONLY THE FINEST SOUND COMPONENTS-ALLOW OUR STAFF OF AUDIO EXPERTS TO HELP YOU CREATE YOUR "ULTRA DEFINITION" SOUND SYSTEM. CHOOSE FROM THE WORLD'S FINEST COMPONENTS LIKE: Hours: TO - 6 Monday through Saturday. We accept Master Charge and Bankamericard We ship mail order in continental U.S., prepaid. CANADIANS ED FOR MORE ELECTRONICS -Audio Research, Lecson, Quad. BGW Ampzilla, Dayton Wright. Paoli, Yamaha, B&O Citation, Stax, Radford band (5 Hz!) feedback suppression, detailed regenerative response. Acousta-Voicing/environmental equalization (±1dB scriptors, etc. AUDIO TECHNIQUES, 351 South Baywood. San Jose, California. 95128. Phone 408-984-6655 weekdays 11-8. weekends 12-6. SHURE SME and other tubular tonearms THE DKL LABORATORY, INCORPORATED HAS DEVELOP- IMF Super Compact Linn-Sondek, The Michell Engineering TURNTABLES Transcriptors, B&0 3000-2 and 4000-2, and Yamaha 781-0215. ADC, Allison Acoustics, BGW, Burwen, Decca, Dynaco, ESR, Harmon Kordon. Linn Sondek. Quad, Soundcraftsmen, Tran- DYNA MARK III I Ampex GRANDMASTER tape on 10'/" metal reel, six for $73.00. New 4 channel 8 -track blank cartridge loaded with 40 minutes Scotch L/N tape. $23.00 per dozen. Reconditioned NAB metal 101/2" reels. $24.00 per dozen. 10% on above for postage. Soundd Investment, POB 88338. Dun woody, Ga. 30338. DECCA MKV AND "EXPORT" SPENDOR BCII and BCII'. Audio ReLOUDSPEAKERS search Corporation Magnaplanars, Quads, Magnepan, Allison and II, Bowers & Wilkins. FMI including the J System, Gale, M&K Sub -Woofers, Dayton Wright XG-8 Mark Ill, IMF Small man Transformers AMPEX TAPE -NEW 1800' on 7" reel 12 for $18 POSTPAID; 1200' 12 for $13 POSTPAID -free list -WIDE RESPONSE, 6114A SANTA MONICA BLVD., HOLLYWOOD, CA. 90038. RABCO SL8(E) DYNA PAS -3)X) SOUND COMPONENTS, INC. is THE place for state of the 83 North University 20 North Carbon DECEMBER, 1975 SATURDAY 2-8PM FRIDAY BY APPOINTMENT ONLY. CLOSED TUESDAY (301) 588-8257 STATE-OF-THE-ART comes to NORTH -CENTRAL FLORIDA, serving you with: AUDIO RESEARCH, Citation, Crown, Dahlquist, Denon, Dynaco, Fidelity Research, DBX, G.A.S. Co., Hartley, Infinity, Magneplanar, Mark Levinson, Ortofon, Rab co, Revak A-100, SME, Sopen, Thotens, Transcriptors, and $10,000 worth of test equipment for in-store audio analysis. We maintain a mobile recording van and sell professional recording equipment. AUDIO, ETC., INC., 1999 N.W. 43rd Street, Gainesville, Florida. 32605. 1-904-377-4107. TEAC '/r TRACK tape deck model 7030 GSL, mint. $700 firm. You pick up in R.I. (401) 766-6019. LOW NOISE RESISTORS -1/4W,5% carbon film from 103.3 Megohm for 31/2 each. Fifty per value is $1.25. 1N4004, 1N4148 diodes. Postage 75c. COMPONENTS CENTER, Box 134A, New York, N.Y. 10038. 109 www.americanradiohistory.com AmericanRadioHistory.Com AN IMPORTANT ANNOUNCEMENT Parnassus Audio is now producing a full Class A (not AB) stereo power amplifier capable of relatively high output power. The amplifier additionally satisfies the theoretical criteria for completely eliminating transient intermodulation distortion. The difference in sound quality between this amplifier and conventional amplifiers is easily audible, even to the inexperienced. We welcome requests for a descriptive brochure. Dealerships will be limited. Address all inquiries to: PARNASSUS AUDIO, INC., 2911 Harper Street, Berkeley, California. - High Quality Audio Has Finally Arrived! Audio Research, Bang & Olufsen, Klipsch, Audionics, Radford. Revox, Bozak, Crown, DBX, Sequerra and others ... THE MINNEAPOLIS SOUND ENVIRONMENT, Butler Square, Suite 114, 100 North Sixth Street, Minneapolis, Minn. 55403, (612) 339- 4641. DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES WAREHOUSE OF BETHESDA P.O. BOX 34251, WEST BETHESDA, MD. 20034. PROFESSIONALLY SPEAKING...Klipsch, Nakamichi, Crown, Yamaha, SAE, Bose, Burwen, DBX, Soundcrahsmen, Transcriptor, Microacoustic, Teac, Sonab, Ookorder, Supex, HAL'S Grace, JBL. For that extra personalized service visit STEREO SOUND CENTER, INC.. RT. 1 & Texas Ave., Trenton, - N.J. FOR SALE FOR SALE FOR SALE 08638, 609-883-6338. - ENGINEERED ENCLOSURE & CROSSOVER DESIGNS free w/purchase of our J.B.L., Gauss. Altec, and Community raw drivers and horns. Music & Sound Ltd., 11-1/ Old York Road, Willow Grove, PA 19090 (215) 659-9251. Loudspeaker Reconing Labs For Rabeo SL -8(E1-5100.00. Transcniptors-free' ('with purchase). S.M.E's-$30.00' Fee NOW LISTEN to our calibrated Satin/Denon/F-R/Ortofon/Supex moving coils. B&O/Grace/Micro-Acoustics. From the laboratories of Music & Sound Ltd., 111 Old York Rd., Willow Grove, Pa. 19090 (215) 659-9251. Levinson & Stax Cartridge Preamps N ORTHERN Ortofon, Phase Linear, Pioneer, Quintessence. Thorens. Write or call University Stereo, 57 E. Ridgewood Ave., Ridgewood, 447-5700. CROWN SX-724, IC-150, 0-150, Burwen, RTR HPR-12 Magnums, Nakamichi 700. (215) 942-2161. - N . CALIFORNIA'S CUSTOM IMF DEALER is now offering: Smaller version of the IMF SMALLER MONITOR world -acclaimed MONITOR! IMF MODEL RII Flat to 20 Hz. Stunning transient attack! extraordiUses new version of KEF flat woofer. At $330 nary! - - - ABSOLUTELY THE LOWEST PRICES on name brand stereo components. Send for our free catalog to BOSTON STEREO INC., 1589 Commonwealth Avenue, Brighton. Mas- Dual transmission line sysIMF SUB -WOOFER KIT $25011 tem flat to 6 Hz Both newly "imSTUDIO IIIB and MONITOR MK IV sachusetts 02135. MARANTZ 10-B. Complete set of spare tubes $750. Glenn English, (512) 478-2054. pulse" revised! Custom demonstrations in The IMF Listening Room. For information and/or listening appointment, write or call Russ Goddard, CUSTOM IMF DEALER, 1171 W. Latimer, Camp- BURGLAR alarm dialing unit automatically calls police. $29.95. Free literature. S&S SYSTEMS, Box 12375H. North bell, California 95008. (408) 374-4691. Mail order customers: For your convenience. all orders are shipped prepaid and insured by air! Kansas City, MO 64116. AMPZILLA - THAEDRA Sound Advice, 536 State Road, Emmaus, Pa. 18049. Hours: Daily 6-9:30: Sat. 10-6. - Big Band Era. RUMBLESEAT RECORDS - new label Send for free catalogue. Rumhleseat Records, P.O. Box 233, Irvington, N.V. 10533. ATTENTION WESTERN NEW YORK AUDIOPHILES The word is getting around!! Our personalized, honest service and quality equipment make a winning combination. In addition to the incomparable AUDIO RESEARCH line, (T -18's black/natural in stock), we carry AMPZILLA SAE, Phase LinQuintessence, LEVINSON, B&0, IMF. MAGNE PAN, M&K Subwoofers, Hegeman, Infinity, RTR, ESS, DAHLGUIST. Fulton Music, QUATRE, Onkyo, Connoisseur, Technics, Thorens, Dynaco, Transcriptors, Cerwin Vega, Sound ear, Yamaha, craftsman, Sapes. Ortofon, ADC, Micro-Acoustics, Damped SME, Linn Sondek, KMAL, Naim Audio. etc. The Stereo Emporium, 3407 Delaware Ave., Buffalo, N.Y. 14217. (716) 874-3372. AUDIOPHILES WANTED!! Put your knowledge to use, earn excellent spare time income. We need campus representatives to sell name brand stereo equipment at substantial discounts in your area. No investment necessary. For information and application please write: ABCO, Dept. CR, 915 Grand Avenue, New Haven, Conn. 06511 - Infinity CAROLINA'S ONLY AUDIOPHILE CENTER Servo-Statiks, Switching amp, Ampzilla, Dahlquist, Magne pan, FMI, Ortofon, Crown, Accuphase, SME, Decca, Hegeman, Klipschorn, Tchnics, Teac, Marantz, Harmon Kardon on dem- onstration. - Vickers Audio 210 West Franklin St. Chapel Hill, No. Carolina 27514 (919) 929-4554 110 Transcriptor, Jordan -Watts, Lowther, KEF, Rogers, SME, Ariston, HPO, Sugden, Radford, Neal, Ferrograph. etc. Shipping lists free or send $3.00 bills to include literature. Goodwin Ltd., 7 Broadway, Woodgreen, London N.22. Phone 01-888-0077. Visitors welcome. CITY ST. LOUIS' LEADING QUALITY AUDIO DEALER -Featuring the following equipment: AUDIO RESEARCH ACCUPHASE PHILIPS AKG QUAD ALTEC PRO QUINTESSENCE B&0 REVOX 700 BOZAK RTR CITATION SCULLY DECCA STANTON STAX TANDBERG EPICURE KMAL LINN SONDEK NAKAMICHI vestment! GREEN BANK SCIENTIFIC, Box 100E, Green Bank, WVa. 24944 FAIRFIELD COUNTY AUDIOPHILES TAKE NOTE! THE AUDIOPHILE, 231 BEDFORD WESTCHESTER AND STREET, STAMFORD, CONN. specializes in equipment for the connoisseur. Ampzilla, Koss Model One, ADC, Citation, Crown, Dahlquist, Dyna, Epicure, Infinity, Philips, SAE, SME, Stax, TEAC, Technics, Thorens and many more (203) 348- UHER YAMAHA PHASE LINEAR and others Equipment tested before being shipped prepaid. J.C. Gordon Company 2831 Hampton Avenue St. Louis, Missouri 63139 (314) 647-8866 Since 1927 NEW GENERATION Crown Amplifiers, Cleanest, Smoothest sound ever produced - Crown 01200/HP1200, on demo only at Barclay Recording, 503 Haverford Ave.. Narherth. Pa. 19012. (215) 667-3048. FLORIDA AUDIOPHILES! Phase linear, I.M.F., B&O, HAIK, Marano, Quatre, Thorens, Sony, Klipsch, Revox, Barzilay cabi- 3038 N. Federal Highway, (305) 566-3511. N ORTHWEST'S FINEST Ft. Lauderdale, - Florida 33306. Audio Research, Audionics, Braun, Burwen, Crown, Dahlquist, Dayton Wright, Decca. Denon, Dunlop Clark. Fidelity Research. FMI, Gale, GAS, Grace, Hartley, IMF, Linn Sondek, Magnepan, Mark Levinson, Nakamichi, Otani. Quad, Quatre, Quintessence, Radford, Se querra, Stax, Supex, Tandberg, Technics, Yamaha, also Custom Designed Superwoofers, and many more, HARTLEY 1502 Butternut, Richland, WA 99352. (509) 946-4459 until 6:00 PM, Then 946-1529 evenings. ELECTRONICS, N AME BRAND RECORDING TAPE, custom loaded. Avail- 3551 (Closed Mondays). - Mel Schilling. formerly of Willow Grove, Pa., has taken his knowledge of music and sound to California, where he will continue to serve a select nationwide clientele devoted to ultra state-of-the-art stereo. 20929 All shipments prepaid and insured. Write or call Ventura Blvd., Woodland Hills Village, Woodland Hills, - Calif. 91364. (213) 348-4600. CASSETTE LABELS: 1,000 labels sheeted 6 up or typewriter roll, $9.95. Shipping 10%. TARZAC, 638 Muskogee Avenue, Norfolk, Virginia 23509. able in cassettes, reels, and cartridges. Huge savings direct from manufacturer. MJS, 516 Brooks, San Jose, Calif. 95125. facturers. FREE classified advertising information and copy form available with each issue. $1.50. Box 94, Colmar, Pa. M&K Audio Research Gale Quintessence Techniques Dahlquist Hartley Quatre Braun SME SAE YELLOW PAGES OF AUDIO-Comprehensive reference to professional as well as consumer audio products and manu- 18915. TECHNICS nets. Sales and expert repairs. INTERIORS PLUS SOUND, SURPRISE! SURPRISE! Digital Piano Tuning Device tunes musical instruments Accurately! Perfectly! Inexpensively! Construction -Instruction Plans Complete $12.95 Airmailed Postpaid! Moonlighting quickly repays $40 electronics in- MAKING HIS MOVE an - BUY DIRECT FROM ENGLAND'S HI-FI MAIL ORDER SPECIALISTS! Save, on B&0, Celestion, Decca, Tandberg, Revox. P.O. BOX 917 HENDERSONVILLE, TENNESSEE 37075 NAME ADDRESS N.J: S FINEST AUDIO STORE, 20 minutes from N.Y.C. Ampzilla, Avid, Bozak, B&O, Crown, Dahlquist, DBX, Dual, IMF, Kenwood, Magneplanar, Micro -Acoustics, N.J. (201) TE -200 TELEDAPTER EASILY CONNECTS TO ANY TV a STEREO SYSTEM. Using our coupling end mama circuit, teledpter takes HIGH a low impedance output from the television and delivers two IMPEDANCE CHANNELS OF SIMULATED STEREO, to drive any amplifier. Frequency response is maintained so you can hear the tinkle of service warranty TV. With bells or booming bass sounds as it happens on TV 100% and hookup instructions S16 95 ppd. Guaranteed to make your more enjoyable. OUR NEW TE300 VHF -UHF HI-FI TUNER IS NOW AVAILABLE. A connec-UHF antenna volt VHF 110 tuner. self contained and complete Recording and amp output jacks. Fire y.er service warranty tions 5109.95 ppd. From our factory. SEND: CHECK D MASTER CHARGE NO. for [7 TE -200 7E300 TO: RHOADES NATIONAL CO. DEPT AD or $5.00 for C.O.D. The PROPRIETARY CUSTOMIZED MODS reduce tone arm friction, damp spurious resonances, minimize torsional forces, improve tracking, and reduce hum and record wear. For KMAL Supex Yamaha Win Labs Audionics Nakamichi Linn Sondek Fidelity Research Mark Levinson Connoisseur Magnepan Sequerra Fulton Grace Stax DBX GARLAND AUDIO. INC. 2960 Stevens Crk. Blvd. 95128 (408) 244-6724 San Jose, California AUDIO DECEMBER, 1975 FOR SALE FOR SALE audio 25 Aberdeen Drive CO Huntington, Next York 11743 C e AUDIO EQUALIZER new BASIC STEREO PREAMP PREAMP ZERO -DISTORTION Check No. 56 on Reader Service Card electronics AND SIGHT, INC. 20 N. Uher, Yamaha. SOUND Federal Highway, Boca Raton, Florida GAS M&K Quad TUBE EQUIPMENT: McIntosh, Marantz and Dynaco. Klipsch speaker wanted. 4430 Wheeler, Houston, Texas. (713) 747- Gale Heroic 4682. Polk Quatre MAGNEPLANAR TYMPANI 3 -A's, mint, neutral fabric, with bass screens. Call (919) 449-4132. Stax Radford Braun Ampzilla C/M Beyer Labs Quatre Audionics Cambridge Magnepan Parnassus Quad ESL Quintessence Audionics Cambridge Dahlquist Sennheiser Beveridge ESL Mark Levinson tofon, PHASE LINEAR, PML, REVOX, SAE, Sennheiser, Sequerra, Sony, Stanton. Stax, Supex, Tandberg, TASCAM, Technics, Thorens, etc. HI-FI HAVEN record -playing equipment KMAL Dual Lamb Grace Beyer Supex Braun Win Labs Connoisseur Revox Vac-o-rec Keith Monks Linn-Sondek Nakamichi Quintessence Fidelity Research Sheffield Mark Levinson LOW NOISE STEREO PREAMPLIFIER. In limited production. Ask your dealer or contact Burwen Laboratories, Dept 11, 209 Middlesex Turnpike, Burlington, Massachusetts, 01803 Tel. 617-2731488 Model SP5200. New! 50 dB per octave crossover, bandpass 16 brands Lowest prices. Audio, Suite - all major 47, 947A Dyer Avenue, Cranston, R.I. 02920. FREQUENCY EXTENDER -EQUALIZER Model EQ3200. New! In limited production. Ask your dealer or contact Burwen Laboratories, Dept 11, 209 Middlesex Turnpike, Burlington, Massachusetts, 01803 Tel. 617-273- 1488 - new hours Sun -Mon 12-5 PM 6-10PM closed Free PassiveX-over Design w/Purchase + SAL -A -THON - Bring cash today and take it away. Low prices on used test equipment. Subject to prior sale FOB, Brockton: Simpson Handiscope 100 Khz, $55.00; HP 120AR w/PII 200 Khz mod., $95.00; $95.00; 4000 VTVM 10hz-4Mhz, lmv-300e, $75.00; HP ers. We ship pre -paid. For competent, professionally objective advice call: STEREO ONE 1229 Post Road 203-255-5939 THE AUDIOPHILE At last! An audio dealer in the Washington, D.C, Metropolitan area serving the sound purist. Audition the new DB Systems preamp -absolutely the finest sound available today, tube or transistor. Listen to your favorite records through the Stax SRX Mk II electrostatic headphones or Quad ESL's with M&K sub -woofer. The sound may surprise you. 582 N. Frederick Md. 20760. (301) 948-2999. Where AC HP 202A F.G. .008-1200 GATELY PROKIT SM -6 mixer. EQ-6 equalizer, EK-6 reverb. Excellent. $550. Nelson Wright, 617-767-0493 evenings. hz, JBL 061 S7R's (2), $400 each; AR32's (2k $150 each; Advent Frequency Balance Control, $100; Dual 1229 with Shure V-1511, base & dust cover. $125.00; AR-XA with Empire 999, $60: Kenwood KA5002, $110; Koss E9 headphones, $125; Kenwood KT -6005, $200. (606) 272-6896. $375.00; STEREO COMPONENTS: Over 50 brands & accs. List 50c refundable Custom Audio c/o Dick Walen 4226 Robert St. Red Wing, Minn. 55066 aha, Phase Linear, Jecklin Float, & Bi -Amplified Bozak Speak- $95.00: GR 1330A bridge osc. 5k-50Mhz, 1021A 40-250 or 250-900 Mhz, $275.00; HP 523D counter 1.2Mhz, per TIM, $120.00; Decade .1 ohm111megohm 9 decades, S49.00. WALLEN ELECTRONICS CO., INC., 46 No. Manchester Street, Brockton, Mass. 02402. (617) 588-6440, (617) 472-0244 mark CERWIN-VEGA PRODUCTS (312) 581-7436 a new excitement to your listening pleasure. Stereo One is at 1229 Post Rd., Fairfield, Conn. 06430. For the discriminating listener we offer McIntosh, Mark Levinson, Braun ADS, Quatre, Nakamichi, Rem, Thorens, Supex, Oahlquist, Ortodon, B&O, Denon, F -R, JBL, Yam- PHILA.'S IMF ROOM - Separate facilities to hear the exquisite sound of IMF louspeakers. (215) 667-3048. sient response, higher definition. Complete instructions, schematics, parts list, $5.00. With parts kit, including all new tubes, $58-00. Or we will modify $105.00 all postpaid. Audio Designers, Box 122, Ledyard, Conn. 06339. CROWN CX-822, mint. $1700; DC -300A, case, S600; Shure M-67 mixer, $100. Robert Busk, 1203 N.W. 4th Ave., Gainesville, Fla. 32601. (904) 373-3043. Mark Levinson, Nakamichi, Burwen, UREI, RTR, DBX, Ortofon, Decca, HK-Rabco, AKG, and more. Crown tape recorder specialists. Send for free catalog! 503 Haverford Avenue, Narherth Pa. 19072. (215) 667-3048. Tek 105 sq. wave gen. 25hz-1Mhz, $75.00: Tek 181 time DYNA STEREO 70 MOD KIT. Tighter bass, improved tran- SAE MARK 1M preamp with cabinet, mint. $410. Call (518) 783-6890, evenings. Duluth, Minn 55811 quality is foremost. private appointments for auditions & consultation 5285. - CYBERACOUSTIC LABORATORY is a research and development meter combined with the most scientifically advanced audio/acoustics lab; featuring Crown, IMF, Ave., Gaithersburg, 617-924-0561. open for browsing LOOKING FOR HIGH QUALITY "PREVIOUSLY OWNED" MERCHANDISE? Referral/resale service for industrial and professional audio equipment. All merchandise guaranteed to meet manufacturer's specification for 12 months (parts, labor, and round trip shipping included). Call or write OHRWERKE, 40 High Street, Guilford, Conn. 06437, (203) 453- Northern Minnesota's finest Audio dealer. Crown, SAE. Infinity, Yamaha, Ortofon, Shure. Thereon, Pioneer, Sony, Kenwood, E -V, Teac. Finest selection will ship prepaid. SOUNDAMERICA 2116 Maple Grove Rd., Phone Gasman Tues -Sat SOUNDAMERICA Fairfield, Conn. 06430 DEALERS: We will buy your excess stock. ALL lines, no quantity too large or small. Cash paid immediately. Call M. (415) 843-5836 - CAR STEREO hz...$1495. DAHLQUIST, F.M.I., I.M.F., HARTLEY SUB -WOOFERS, for the closest approximation to dipole definition $132 up! Shipped prepaid/insured. Music and Sound, Ltd., 11V2 Old + Berkeley, California 94705 AUDIO - INFRA WOOFER TM world's largest, deepest, most powerful sub -woofer system can be had only at Music and Sound, Ltd. York Road, Willow Greve, Pa. 19090 (215) 659-9251. STEREO WORKSHOP 2985 College Avenue - LET STEREO ONE bring 201-249-5130 BSR Dbx AKG, ALTEC, AUDIO RESEARCH, Beyer, CROWN, DAHLQUIST, DBX, DECCA. INFINITY, KLH 9s. Koss, Nakamichi, Or- 28 Easton Ave. New Brunswick, N.J. 08901 SME ARK - Listen to every speaker available SHOP AROUND then come to Cyberacoustic Laboratory and hear RTR's New Direct Drive Electrostatic DR -1 speaker system at Phila503 by appointment delphia's exclusive distributor Haverford Ave., Narberth, Pa. 19072. (215) 667-3048. ADS FMI Fulton tape -recorders, processors, & accessories Technics, Transcriptors, Tandberg, DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES WAREHOUSE OF MOBILE, 1770 BELTLINE HIGHWAY, MOBILE, ALABAMA 36609. BERKELEY, CALIFORNIA ADS 1 B&0, Crown. Denon, Fulton, IMF, Magnepan, Marantz, Mark Levinson, Nakamichi, Paoli, Phase Linear, Revus, Russound, SAE. Satin, Sequerra, Sherwood, Shure, Stet, STR, Supex, 33432, (305) 391-1843. fr<'t' catalo.x with tc'.St ('(7)0111 speakers & headphones FOR SALE FLORIDA'S LARGEST AUDIO RESEARCH DEALER. Full Audio Research Systems on display SP3-A-1 Dual 76A/Dual 150/Dual 52/Magneplanar Tympani C/Tympani IV. Plus AR. gen., GR DON'T PAY THE HIGH MAIL ORDER PRICES THIEVES OF TAMPA, 1531 SOUTH DALE MABRY, TAM- YOUR ROOM IS THE MISSING LINK WAREHOUSE PA, FLORIDA 33609. TORONTO AREA FM FANS: Get the full story on local programming, new products, dealers, record reviews. The FM Guide, 122 Davenport Road, Toronto M5R 1H9. One year, $7.00. ORIGINAL TRANSCRIPTOR HYDRAULIC REFERENCE TURNTABLE (do not confuse with smaller "Skeletal" table/Vestigal arm package from Ireland) now available direct from U.S. importer. Magnificent turntable complete with silicone -damped Unipivot arm, $498.00 freight prepaid. Without arm, including blank arm -mounting board or one cut for SME, $398.00. Send $100.00 down for COD shipment. Audiophile Imports,1OEast Erie, Chicago, 60611. (312) 7870754. West Michigan Audiophiles-Paoli, Ampzilla. Transcriptors, Magnepan. Fulton. Available at Music CenterEquinox, (616) 457-2117, or Box 333, Grandville, Michigan 49418. DECEMBER, 1975 A state of the art system is usually junk in the typical poor listening environment, and therefore a rip-off. Our acoustical consulting division will have a calibrated "reverberation curve vs. frequency" measurement performed in your room, and our engineering dept.'s plan of correction, loudspeaker placement, and room equalization, all at no cost with your purchase or upgrade. Music & Sound Ltd., 111/2 Old York Rd., Willow Grove, Pa. 19090. (215) 659-9251. on over 96 leading Hi-Fi brands. Many exclusive factory closeout and special deals. Quotations via return mail. Nationwide mailorder service. CANADIANS: Best Hi-Fi discounts catalogs jam pack with bargains in: Hi-Fi equipment, tape and recording accessories, calculators, telephones and accessories, kits, parts, etc. Hundreds of factory and government surplus specials too! American inquiries welcome. Rush free catalog request to: ETCO, Dept. AUA, Box 741, Montreal H3C 2V2. FREE 111 www.americanradiohistory.com AmericanRadioHistory.Com FOR SALE I. CONSIDER YOUR SOURCE FOR SOUND Credentials College instructors in audio /acoustics, Inventors/graduate electrical engineers, Recording & disc mastering engineers:MEMBERS:United Inventors & Engineers Acoustical Society of America Institute of Electronic Engineers II. Facilities Aoechoic Chamber: >.91 working floor $50,000 research laboratory Factory authorized "A" warranty stations Loudspeaker Reconing Lab III. FOR SALE FOR SALE Our Distinguished Suppliers Audio Research, Sequerra, Satin/Denon/F-R, Transcript - NEEDLES STEREO CARTRIDGES -ADC, B&O, SHORE, STANTON, SUPEX, SONY, PANASONIC, RCA, BSR, and others. Write for FREE CATALOG. NEEDLE IN A HAY- STACK, INC., P.O. Box 17436, Washington, D.C. 20041. NOW IN PRODUCTION: World's heaviest 12" woofer. 17Hz resonance. Over 200 watts RMS. Sand cast frame, $59.00 delivered U.S.A. Rockwell Systems, Inc., 100 Liberty St.. Rockwell, N.C. 28138. NOW THE BIG MID-RANGE: 3" dome, 3" voice coil, 96 watts RMS sine wave power at 1000Hz. Over 120 degrees dispersion 500 to 5000 Hz. Weight 121/2 pounds. $99.50 postpaid USA. ors, F.M.I./R.T.R., Linn Sondek, Nakamichi, Dayton Wright, AR -3A Dahlquist Crown, Infinity, I.M.F., London Decca, Quad, Rogers, Spendor, Stax, B&0, Grace, Supex, Micro Acoustics, Custom Rabco, Braun, Revox A-700, Ortolan, Damped (804) 282-5918. S.M.E., Scully, Mark Levinson, Koss-ELS, Yamaha. AND GRADO EMPIRE, MICRO -ACOUSTIC, PICKERING, ORTOFON, - like new, walnut stands plus glass tops. $250. P.A. ad). Music á Sound Ltd., 11,E Old York Rd., Willow Grove, Pa. THOUSANDS OF LIKE NEW LP's and prerecorded tapes. Catalogue $1.50. House of Records, Hillburn, New York 10931. WESTCHESTER HEADQUARTERS for the great sounds in the world. Quad, Cambridge, Dahlquist, Bose ESS, Braun, Nakamichi, Technic, BGW, Dual, Revox, Leak, B&O, DBX, Burwen, We stock Ampzilla. The listening Room, Inc. 590 Central Ave. Scarsdale, N.Y. 10583 (914) 472-4558. IMF MONITOR Mk Ill's, perfect condition. (814) 2385016; evenings call (814) 238-7883. AUDIO'S HI-FI HANDBOOK CROWN, DBX, KLIPSCH, KMAL, LINN SONDEK, NAKAMICHI, reference guide to over 1,000 components, including prices and specs. All arranged in tabular form for easy comparison. Plus over 30 outstanding articles on audio PHASE LINEAR, RADFORD, REVOX, SEQUERRA, STAX, TAND - topics, trends and advances. State-of-the-art reading for audi- BERG, BEYER, SENNHEISER, and other fine instruments for the reproduction of music. Send for list of used equipment AUDIO SYSTEMS AND DESIGN, 5421 South 84th St., Lin- ophiles. Only a limited quantity available. Over 200 pages. Send $3.95 (includes shipping and handling) to: Jean Davis, Audio Hi-Fi Handbook, 134 N. 13th St., Phila., Pa. 19107. coln, Nebraska 68516 (4021 489-9888 ... and 4408 Capital Ave., Omaha, Nebraska 68131. (402) 556-7559. MILWAUKEE AUDIO RESEARCH, AUDIONICS, BANG&OLUFSEN, BOZAK, PROTECT YOUR LPs- Poly sleeves for jackets 8c round bottom inner sleeves 6c Poly lined paper sleeves 15c White jackets 35c Postage $1.25. House of Records, Hillburn, New York 10931. NEW YORKERS-WE ARE COMMITTED! Consult with us about your audio needs. We have what you want, we offer FULL service. Complete & WISCONSIN'S only audiophile dealer. Specialists in components by Crown, Dahlquist, Transcriptors, Integral Systems, Epicure, Nakamichi, Bozak, Citation, Ohm, SME, Ampzilla. DBX, Infinity, SAE, RTR, ESS, Revox, Phase Linear and 50 others. Wisconsin's only Audio Research dealer with the entire product line on demonstration. WACK ELECTRONICS INC., 5722 W. North Ave., Milwaukee 53208. 414-442-3441. -SPEAKER CATALOG IMF, BGW, SAE, OHM. INFINITY, KLIPSCH, ORTOFON, THO- Up to date. Top quality drivers. Hop -up the speakers you have or build new ones. Transmission -line speaker plans $5.00 -Foam damping material. E&E Audio, 2816 Church KENWOOD, CROWN, MARANTZ, TANNOY, KEF, IAS, DBX, REVOX and Many Others. INNOVATIVE AUDIO 129 DeGraw Street Brooklyn, NY 11231 (212) 596-0888 Call For Appointment THE JANIS WOOFER IS ABSOLUTELY FLAT TO 30 Hz.! The specifications can only hint at the effortless, ultra -clear and detailed bass reproduction to the limits of hearing. Typical response 30 - 100 Hz. + 1/2dB, distortion about 1% max. About 60 W is enough to drive this speaker. Elegant in size (22"x22"x18" high) and appearance. Full details: Janis Audio Associates, Inc.; Box 88 Throgs Neck Station; New York, N.Y. 10465. HONG KONG, TAIWAN, JAPAN, Asia Directory. World products information. Mail -orders, bulk -orders. Listings. Directory and Information $1.00 today. World Trade Inquiries. Box 6224, Spokane. Wash. 99207. ALAN AUDIO OF INDIANA Ave., Brooklyn, New York 11226...212 462-0984 - the second issue includes SOUND ADVICE MAGAZINE comparative reviews of amplifiers: Audio Research Dual 76A; C/M Labs 912; Electro Research Class A; Luxman 4000; Naim NAP160; SAE 2500; Stax High Powered FET Class A; and Technics SE9600. Preamps include Audio Research SP3a-1; Crown IC -150; Dayton Wright Sps; Dynaco PAT -5; ESS preamp; Harman Kardon Citation 11a; Levinson JC-2; Luxman C-1000; McIntosh C-28; Naim NAC12; Phase Linear 2000; Radford; Soundcraftsman 2217; Stax FET; and Technics SU9600. Cartridges reviewed: Audio Technica AT2OSLa; Decca V Elliptical; Empire 4000D/Ill; Shure V15 Type III; and Stanton 681EEE. Some extra goodies: Keith Monks Tonarm; Linn-Sondek turntable; IAD Dynamic Range Expander; Dayton Wright and Levinson Jc-1-AC moving coil pre $9 (S11 first class; amps. Much more. Four issues $12.50 foreign sent airmail). Sound Advice, 225 Kearny, No. 200M, San Francisco, Calif. 94108. - - THE BOTTOM END, as reviewed in the April Stereophlle. ADVENT, ADS/BRAUN, AVID, CITATION, CROWN, FULTON, A new compact super bass speaker that retails for around GALE, LINN-SONDEK, NAKAMICHI, OHM, ORTOFON, REVOX, $200.00. YAMAHA Amplifier & tuner testing; cartridge comparisons; fully instrumented factory authorized service Alan Audio, 310 S. Washington, Bloomington. Indiana SHURE, SME, SUPEX, TANNOY/MICRO, 47401; 812-332-2192 Open Sunday, Closed Saturday. MIDWESTERNERS ING TAPE - Write for COMPONENT AND RECORDBox 477, Notre DISCOUNT PRICE LIST. AUDIO, Dame. Indiana 46556. diIIN DISCOUNT MUSIC DEPT. CLUB, INC. 650 Main Street, New Rochelle, N.Y. 10801 14-125 J CURRENT AND RECOMMENDED: Originally developed as a mix down monpeizoelectric has been added for dispersion. The result is a very efficient, accurate reproducer with very good power handling. $185 each. SONEX speaker. itor, a power amps by Dunlap Clarke. Absolutely protection. Despite other claims this is the first solid state amp we have heard which is as good or better than the best tube equipment we have heard. We used to have to specialize depending on what the amplifier was to he used for. This is the amp for super -woofers or any part of a bi or tri amped system, or for PA or band use. Models 500 and 1000, $800 and A no -compromise performer with smooth rebelow 20 Hz. Ideal for use with Magnaplanars, Quads, Dahlquist, ESS, or any system deficient in low bass, sponse of permit the does it all. all others. because quest, room placement. BOTTOM END CROSSOVERS use of one woofer, no bi-amping, one amplifier Model X1 for all Magnaplanars. Model X2 for Literature and information available upon re- dealer name of your inquiries invited. $1200. These amps will also be available under the Sequerra name with different cosmetics. SUPEX SMM5 moving magnet cartridge. Not the best but exceptionally smooth. Nothing can touch it for $50. Consumers write for the K Sound Inc., 8719 nearest dealer. M & Wilshire Blvd., Beverly Hills, Calif. 90211. 940 oil damped, uni -pivot tone arm. $149. RESEARCH cartridge and transformer. The best GRACE FIDELITY moving coil yet. Highly regarded even by resident Decca freak. Great depth of image and detail. Also variety of prepreamps. Cart. $130, Torodial transformer 5150. AUDIO P50 and P140 integrated amplifiers CAMBRIDGE with toroidal power supply and state of the art preamp. $350 and $550. Also TL 200 transmission line speakers, DECCA BRUSH. Over a million conductive bristles eliminate need for liquids and reduce static. $15. DECCA CLEAN-UP, The ultimate dust bug. Same bristles as brush, conductive shaft and ground wire. $15. also: GAS Ampzilla, Dayton Wright. C/M Labs, Sony, Lux, BGW, Audionics. Lexson, Revox, Otari, Nakamichi, Neal, FMI, Celestion, IMF, Linn Sondek, ERA, Micro Shipped free anywhere in U.S. and Canada. GREENWOOD SOUND, INC. P.O. Box 2069 Portland. Ore. 97202 503 235-1776 BUILT SPEAKER SYSTEMS, enclosures, kits CUSTOM foam grills, crossovers & parts. Raw speakers, vinyls. CSS, 8460 Marsh, Algonac, Mich. 48001. www.americanradiohistory.com AmericanRadioHistory.Com veneers, HI-FI ENTHUSIASTS WANTED!! Earn more than just spare money in your spare time. We need campus representatives to sell name brand stereo components at discount prices in your area. High commission, no investment required. Serious inquiries only, please. Contact: Alan Weisberg, K&L Sound Services Co. 75 N. Beacon St., Watertown, Mass. 02172. DON'T PAY THE HIGH MAIL ORDER PRICES THIEVES WAREHOUSE OF PENSACOLA 3731 NAVY BOULEVARD, PENSACOLA. FLORIDA 32507 MINT SONY PREAMP 2000, $185; Sony SO Decoder SQD2020, $135; Kenwood Audio-Denoiser KF8011, $140; Pioneer SA900 amp, 120 watts rms, $175. (919) 5780655, A. Blanchard, P.O. Box 2034, Burlington, N.C. 27215. DEMO EQUIPMENT . , . BOSE 1801 Stereo Power Amps. $779.00. Braun LV1020A Tri-amped. Speaker System $585.00 each. TELEX 235 series Cassette Duplicator Sys1/2 tr. 2ch. system includes open reel master, cassette master and 3 cassette slaves. System includes consoles and cables. Used only as demo. A value at $2000.00. AUDIO CRAFT CO.. INC., 3915 CARNEGIE AVE., CLEVELAND, OHIO tem. - 44115, 216-241-5560. REVOX OWNERS Factory authorized service, parts & accessories for the Western states. Beverly Stereo Audio Clinic, 8413 Beverly Blvd., L.A., Calif. 90048. 1213f 651-3652. DBX: 119 Compressor/Expander. $125; 1242/4 Channel Noise Reducer, $225. John, 414-782-7398. AUDIO DECEMBER, 112 700. Dual, Decca, Ortolan, Supex, Sennheiser, Beyer. Sequerra. - RENS, SME, LEVINSON JC-1, STAX, ADS -BRAUN, TECHNICS, PIONEER, Discounts up to 73%, no "agree -to -purchase" obligations. All labels, Schwann catalog of thousands of titles; classical, pop, jau, country, etc. Discount dividend certificates. Newsletter; accessories; quick service. 100% iron -clad guarantees. Write for free details, stable, superior 19090. (215) 659-9251. Whom Would You Trust? DIFFERENT KIND OA F RECORD CLUB DREADNAUGHT SAE, EPI, Crown, Phase Linear, Tandberg, Thorens, Yamaha, 1000's of PROFESSIONAL products (see Tuned Rock FREE 1975 FOR SALE FOR SALE TRANSCRIPTOR SKELETON TURNTABLES, for the discriminating audio enthusiast, are now available at Port Of Sound. The glass enclosed turntable in combination with the Vestigal arm offers performance rated among the very best. Port Of Sound, 8665 N. Port Washington Rd., Milwaukee, Wi. 53217. STATE-OF-THE-ART PERFORMANCE FROM THE Transcriptor Vestigal tone -arm on display with the Transcriptor Skeleton turntable at Opus 2, 404 S. Perkins Ext., (901) 683-0117 and Germantown, (901) 754-8431, Memphis, Tn. 38122. Used 1" x 1-3600-R41. A512-1. 3600' video tape, 10" reels, Scotch 551- + $30 each postage. Audio Box number KENWOOD KF-8011 denoiser, $175; Koss ESP -9 headphones, $150. Hobish, 7306 Park Heights Ave., Baltimore, Md. 21208. PIONEER TX-9100 tuner. Very good condition with little use. Shipped prepaid insured for Prospect Ave., Pittsburgh, Pa. $175! Chris Hood, 11 IMF LOUDSPEAKERS, Monitors featured. Levinson, Burwen, Labs, Futterman tubed electronics. Jecklin CM $1000.(919)929-6824. JBL PARAGON, walnut, $1800. Mark Conrad. 1004 Havelock Dr., Taylors, S.C. 29687. (803) 268-6840. STEREO CARTRIDGES and STYLUS REPLACEMENT For ADC. Audio Technica, B&O, Grado, Empire, Micro Acoustics. Pickering, Ortofon, Shure, Stanton, Supex. Write for free catalog: Needle In A Haystack, Dept. A., P.O. Box 17435, Washington, D.C. 20041. - SCOTCH -AMPEX TAPE Lowest prices! Ampex Grandmaster, 101/2", our metal flanges, boxed -$13.50 postpaid. Cheaper in quantity. Free price lists. Omega Audio, 25520 Graham Road, Detroit, Mich. 48239. C22, DOCUMENTED ED: Futterman, Marantz, McIntosh tubed equipment. GOLDEN berg, 908 Lomita, Segundo, Calif. registered name (formerly Audiocraft), South Rockwood, Michigan 48179. (313) 379-9945. STEREO REPRESENTATIVES NEEDED!! Lowest Price List EAR, NO CHARGE TO INSERT ADS! NO COMMISSION WHEN ITEMS ARE BOUGHT OR SOLD! BUY, SELL OR TRADE YOUR HIGH END HI-FI THROUGH AUDIOMART, THE AUDIOPHILE'S cueing Audio Service. 7313 Inzer, Springfield, VA to Daugherty 22151. DYNAMIC SPECIALITIES IS A WEST COAST STORE DEALING PRIMARILY IN USED AUDIO EQUIPMENT. 1. We offer service for vintage tube equipment, Marantz, McIntosh, Citation, Quad, Scott, Fisher, sell & Renos, Ampex, etc. We carry a wide range of used components, vintage & current. 3. We also demonstrate & sell certain new equipment: Fulton, Grace, Supex, Fr. Dahlquist, M&K, Connoisseur. 4. Sample of stock at time of writing - Marantz 8 (2), 7c, 2. SAE IVCM, MAC 2505, MC60 (2). ARC D75A 050FIB, SP3A-1, Quad 303, Crown IC150, Leak TL/12 Plus, Cita- tion I, II, III, Revox G36, A77, TEAC 7030SL, Dahlquist 11010, Sony 777, 2251, Dyna 70 (2), Mk III (2), ST35 (2), 120, Thorens TO12511/SME, & more. Also, Telefunken tubes, photographic & musical instruments. 2261 Spring St. Redwood City, California camped for 94063 415-364-6634 AR/Thorens/ DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES 4166 BUFORD HIGHWAY, N.E. WAREHOUSE OF ATLANTA. SUPEX AC11 stylus cleaner $4.00 ATLANTA, GEORGIA 30345. CM LABS electronic crossover, 6 db. 100 hz steps $158.00 PAC Piezoelectric add on tweeter, two per burl finish en- DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES closure, OF ATLANTA, SMYRNA, GEORGIA 30080. WAREHOUSE db/octave crossover $100.00 pr. postpaid/satisfaction guaranteed Perfectionist Audio Components 172 Ocean Ave., Lynbrook, N.Y. 11563 6 ALL shipped AMT -1 Towers, 341-1148. ESS ESS 1030-3 CHEROKEE ROAD, DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES WAREHOUSE preamp, very negotiable. (301) OF MONTGOMERY, 3386 NORMAN BRIDGE ROAD. MONTGOMERY, ALABAMA 36105. DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES REVOX A-77 TAPE DECK, $375. Robert Sadowsky, 3235 Emmons Ave., Brooklyn, New York 11235. (212) 934-9425. WAREHOUSE MC INTOSH MA -6100, $550. Fisher OR -14 CD -4 demodulator. $60. Integral Systems 200 amplifier with cabinet, $250. Marantz 4000 Quad adapter with cabinet $150, SQA2 SQ logic $50, RC -4 remote $25. Advent 201 $225. Philips GA212 turntable with Shure V-15 type two, $150. Bozak B -305's, $500. Infinity Monitors $700. Call Chuch 313-6537192. DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES * ADC * SAN DIEGO, CALIFORNIA Advent * AKG * AR * Audio Research * Be- * Burwen * Crown * Dahlquist * DBX * Dual * Dynaco * Garrard * Grado * Harman-Kardon * Janszen (electrostatic) * KMAL * Koss * Linn-Sondek * Magneplanar * Maxell * Micro -Acoustics * Nakamichi * Ohm * Philips * Rabco * Revox * RTR * Sennheiser * Sherwood * Shure * SME * Sonab * Sony * Supex * Tandberg * Tapco * TDK * Yamaha Sound Company yer BIC 4701 College Ave. (714) 582-4148 3675 Sports Arena Blvd. (714) 224-2844 - SOUNDTRACKS MOVIES, TV, BROADWAY, RELATED, RARE. $1.00 FOR CATALOG, REFUNDABLE. "MR. SOUNDTRACKS," 59-359 PUPUKEA RD., HALEIWA, HAWAII 96712. AUDIO OF ATLANTA. NORTH LAKE BRIAR CLIFF ROAD, ATLANTA, GEORGIA WAREHOUSE OF MALL, PREAMP, $360; HARTLEY $360; CROWN D60, $220. 1502 Butternut, Richland, WA. EQUALIZER, ELECTRONICS, 99352. 946-4459 or 946-1529 evenings. PERFEL,-0350/offer. Wm. Henne 90245. Buying!! Over 80 Brands!! Krasco Stereo, 623 Campbell Ave., West Haven, Conn. 06516. FORMULA 4 PROFESSIONAL LABORATORY TONE ARM Only viscous damping with low effective mass can ensure natural sound without 'listening fatigue' enabling all cartridges to reach their region of best performance, the socalled "Linear Region' essential for perfect CD -4, UD -4 matrix quadraphony and stereo due to the suppression of instantaneous tracking force extremes reducing record wear and H.F. playback distortion. Viscous damping means better tracking of warped records, the sound having rich full bass plus a tape -like consistency with steady stereo image and near pinpoint localization. Jewelled Unipivot friction below 0.005 gm. Effective Mass 4.50 gm VTF 0-3 gm stylus pivot 224mm. Optimum performance with ultra high or low compliance cartridges weighing 3-10 gms. Leaflet $1 deductible from purchase. Price $89 including airmail. Formula 4, 15 Heather Walk, Edgware, Middlesex HA8 9TS, England. TRANSCRIPTOR SKELETON TURNTABLES, FOR THE discriminating audio enthusiast, are now available from Audio House, LTD. The all glass enclosed turntable in combination with the Vestigal tone -arm offer performance among the very best. Audio House Ltd., 510 First Street, Lake Oswego, Or. 97034. TRANSCRIPTOR SKELETON TURNTABLES, FOR THE discriminating audio enthusiast, are now available from Soundsmith. The glass enclosed turntable in combination with the Vestigal tone -arm offer performance rated among the very best. The Vestigal tone -arm is also available separately for custom mounting on your turntable. Soundsmith, 242 State St., Portsmouth, N.H. 03801. WE BUY, SELL, TRADE DYNAMIC SPECIALTIES $15.00 device, BOX 821, SERVICE MANUALS for all audio equipment. Includes schematic, parts list and servicing. Send make, model and $5.00 SUPEX SL4 6 gram universal head shell $7.00 AL2 $4/12. CLASSIFIED NEWSLETTER. SUBSCRIBE: STRATFORD, CONNECTICUT 06497. GOODY DEPARTMENT KMAL/Rekokut $19.00 USED EQUIPMENT: AUDIO RESEARCH TYMPANI IA, $650; BGW 500R, $495: GALE SPEAKERS, $575; QUINTESSENCE trostatic Headphones. Leak Stereo -20 tubed amplifier, new $200. Beam -Echo rare (English) tubed mono amplifier new $195. RTR 400E electrostatic speakers nearly new $235 each. Sheffield recordings. Bohn Omnitrex SRI portable calculators, regularly $130, now $75. Trades accepted. WANT- e.g., CROWN ES212 electrostatic speakers, $900/pair. (219) 533-9859. SUPEX Float Elec- E. 15205. MARANTZ MODEL 500. Immaculate condition. Will sell for DECCA Megafilme Brush FOR SALE 4800 30345. ATLANTA, 3164 PEACHTREE ROAD, N.E., ATLANTA GEORGIA 30303. AUDIO RESEARCH D75A amplifier $550. Magneplanar Tympani B's $725. (213) 240-1706. TRANSCRIPTOR SKELETON TURNTABLES, FOR THE discriminating audio enthusiast, are now available from Sounds & Settings. The glass enclosed turntable in combination with the Vestigal tone -arm offer performance rated among the very best. The Vestigal tone -arm is also available separately for custom mounting on your turntable. Sounds & Settings, 622 E. Liberty, Ann Arbor, Mi. 48108. TRANSCRIPTOR SKELETON TURNTABLES, FOR THE discriminating audio enthusiast. are now available from KSS Sound. The glass enclosed turntable in combination with the Vestigal tone -arm offers performance rated among the very best. KSS Sound, 9 Music Square West, Nashville, Tn. 37203. TRANSCRIPTOR SKELETON TURNTABLES, FOR THE discriminating audio enthusiast, are now available from Sound Of Music. The glass enclosed turntable in combination with the Vestigal tone -arm offers performance rated among the very best. Sound Of Music. Mpls-St. Paul, and Mankato Mn. and Eau Claire, Wi. 1 TRANSCRIPTOR SKELETON TURNTABLES AND VESTIGAL tone -arms are far ahead of their time. Don't waste time. Come and see them now at: Audio Specialists, 2661 Campbellton Rd. S.W., Atlanta, Georgia 30311. THE TRANSCRIPTOR TURNTABLES, VESTIGAL TONE -ARMS and the world's most accurate stylus scales. Transcriptor turntables are acousticallysonically silent, aesthetically beautiful. Get yours now! Golden Ear (formerly Audiocraft), South Rockwood, Mi. 48179. TRANSCRIPTOR SKELETON TURNTABLES and VESTIGAL tone -arms. Specializing in precision mounting of the Ves- tigal tone -arms on your turntable. Call (412) 441-3770 for appointment. Kevin's Audio Specialties, Pittsburgh, PA. DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES WAREHOUSE OF ATLANTA 2769 LAKEWOOD AVENUE, S.W., ATLANTA. GEORGIA 30315 DECEMBER, 1975 TRANSCRIPTOR SKELETON TURNTABLES, FOR THE discriminating audio enthusiast, are now available from Wack Electronics. The glass enclosed turntable in combination with the Vestigal tone -arm offers performance rated among the very best. The Vestigal arm is also available separately for custom installation on your turntable. Wack Electronics, Inc., 5722 W. North Ave., Milwaukee, Wi. 53208. DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES WAREHOUSE OF NORTH TAMPA, 1441 EAST FLETCHER AVENUE, TAMPA FLORIDA 33612 - FACTORY FRESH BRAND NEW Sherwood S -8900A Primo receiver, $299. TEAC 360S cassette recorder, $305. BASF C-90 chrome cassettes, 10 for $25. Shipped freight collect. Full manufacturers warranty. Stereo WareBuy from the Big One on the West Coast house, 813 Pacific Ave., Santa Cruz, California 95060. (Calif. Res. add 6% sales tax.) All orders shipped same day received. - 113 www.americanradiohistory.com AmericanRadioHistory.Com FOR SALE FOR SALE 3'/x4 $2.25 per 50 and 2x2 $2.75 per 100. Radio Mat Slide Company, 444 N. Peninsula Drive, Daytona Beach. Ha. 32018. TYPE YOUR SLIDE! Sizes - THE ABSOLUTE SOUND, in its seventh issue, will assess the state-of-the-art in audio components. It will review a new generation of components (in depth) that purport to advance the audio art: the Infinity Servo -Statik la; Mark Levin son's new preamp, the John) Curl) -2; Yamaha's low -feedback preamp and its V-FET amplifier; Audio Research's Dual 76A and SP3A-2; the Dayton-Wright MKIII Electrostatic; Luxman's new amplifiers (at 300 and 180 watts per channel respectively); the Denon Spherical and Shibata moving coil cartridges; Rabco's SP -7 straight line tracking turntable. Nor is this the end of it. We shall also be taking a look at the Quad Electrostatic; the Yamaha Super Speaker; the Fidelity Research cartridge; Ohm -F; KEF 104; the Hegeman speakers; Epicure's electronics (amps and preamps) and more. We'll also be updating our recommended recordings, with additional emphasis on record reviews. Subscriptions (four issues): $10 US, $11 Canada. Add $2 for first class mailing if desired. $13 foreign (airmail). Back issues through 6, $3 each. The Absolute Sound, P.O. Box 5, Northport, N.Y. 11768. 1 MARANTZ 500, excellent factory tweeked unit. $800. (919) 467-9198. DECCA INTERNATIONALSUPEX lift, $130. Wharfdale tweeter, 8 -inch woofer, $45. Xover coils: (4) .01 mh; (2) .9 mh, $12. Want high grade tube power amp. Friedman, 606 S. Coler Ave., Urbana, Ill. 61801. for fine used equipment: Pair of Marantz 8b's, Macintosh 240, several Dynaco 400's, Fairchild Compander, KLH 5's, EPI 202's, Quads. DO NOT BUY ANOTHER SPEAKER until you have heard the natural sounding, low distortion Fultons at NATURAL SOUND, 1021 Claremont Street, Lincoln, Ne- 68508. (402) 475-3325 and E-7 Institute and Einhorn. Worcester, Mass. 01609. (617) 755-1461. brasks DISCOUNT PRICES on stereo components. All major brands. Write for quote. Seashore Stereo Sales. 204 Wood crest Ave., Absecon, N.J. 08201. NO MATTER HOW GOOD YOUR COMPONENTS, YOUR am selling a 3900 ROOM IS YOUR WEAKEST LINK! cubic foot SOUNDPROOFED music room with non -parallel ceiling, 14,000 watts AC, super antenna system, etc. With it goes a historic restored 3 bed 2' bath detached townhouse in Alexandria, Va., a short, pleasant (i) commute from Wash I DC. Extras like Thermopane windows. gas CAC, etc, too nu- merous to list. $97.000. Call (703) 549-3054. DAHLQUIST - AMT -3's. Heil monitor speakers. (212) 376-4842. ESS Burwen DNF1201 works on any program source without pre encoding. Eliminates hiss without changing tonal quality of program material. Request information and dealer directory. Burwen Laboratories, Dept. 10. 209 Middlesex Turnpike, Burlington, Massachusetts, 01803 Tel 617-273-1488. SAN FRANCISCO PURSUIT Crown, N. Broad St., Philadelphia, Mass. 01921. 2 SOUND ADVICE SUBSCRIBERS: the entire technical staff of the magazine remains together and continues to create the quality work you expect from us. We are changing publishers. If you wish to receive our magazine, send a xerox of your cancelled check with your name and address to me personally: Peter Moncrieff, 2449 Dwight Way, Berkeley, Cali- fornia 94704. NAKAMICHI 700, mint. 50 Cr02 C-90 tapes. Make offer. McIntosh MPI-4 scope $475. Box A512-4, co Audio. ESS AMT -1 OWNERS: Dissatisfied with bass? Our modification greatly improves performance, leaves warranty intact. Only $69.95 plus tax and shipping. Free brochure. TRANS -BASS SYSTEMS, 2323 S. Otis, Santa Ana, Calif., 92704. VESTID - just one available Buffalo, AUDIO RESEARCH SP -3A-1 preamp offers more sonic imp'-- vement for upgrading an already good audio system than any other component. $695. We trade. We carry the same lines as other audiophile dealer listings. See our Absolute Sound Room. The Stereo Shop. 107 Third Ave. SE. Cedar Rapids, Iowa 52401, and Village Shopping Center, Daven- port, Iowa 52806. D -75A, Sony 2251 w/SME 3009 & Supex SD900E, Sony TA -2000F preamp. New, warranties. Trades considered. 509- Pa. OF 19108. considering any component purchases without it. $9.00year ($11.00 first $11.00 Canadian. P.O. Box 269, Fort 32548. Altec, Technics direct drives, RTR, Transcriptors, Klipsch, Citation, Decca, SME, Sequerra, Micro/Acoustics, Lamb, Dahlquist, Tannoy, Also Yamaha, Soundcraftsmen, Marantz, and more individually damped Altec & custom room equalization, JBL Monitors and an ongoing equipment evaluation program. The House of Sound, 821 Kent Ave.. Baltimore, SAE, Beyer, McIntosh, DBX, JBL, . tone -arm when A -Bed with the others. Audio One, 167 N. Woodward Ave., Birmingham. Mi. 48011, (313) 646-6666. TRANSCRIPTOR SKELETON TURNTABLES, FOR THE discriminating audio enthusiast are now available from A.C. Recording & Electronics. The glass enclosed turntable in combination with the Vestigal tone -arm offers performance 7 U.S. Highway 206, Raritan, N.J. 08869. DECOURSEY ELECTRONIC CROSSOVERS Complete with plug-in Butterworth filters of your specified frequencies and with 6, 12, or 18 db./octave attenuation. Regulated power supply. Bi -amp or triamp for monaural, stereo, or quadraphonic systems. Other options; Electronic summer for single woofer stereo; VLF noise filters. For OEM and home builders; Series 500 and 600 Hi -pass and Low-pass filter pairs. Also regulated power supplies. Write for brochure. DeCoursey Engineering Laboratory. 11828 Jefferson Blvd., Culver City, CA 90230 ARP SYNTHESIZERS! New Rock Bottom Prices Explorer, AXXE $730; Pro -Soloist $875; Odyssey $1165; String Ensemble $1315; Model No. 2600 $2260. Dickstein Distributing, 1120 Quincy Avenue, Scranton, Pennsylvania 18510. AR AMPLIFIER with walnut cover. Excellent condition, 3 years old. Best offer over $130. Orasin, 107 Buckley St., Liberty, N.Y. 12754. NOW AVAILABLE FAMOUS REFLECTING SYSTEM'S 41/2í' REPLACEMENT DRIVERS. $7.98 POSTPAID. QUANTITY DISCOUNTS. FREE SPECIFICATIONS. AURATONE, BOX 580-26A, DELMAR, CALIFORNIA 92014. THE AUDIO RESEARCH ROOM. The complete line of Audio Research equipment on display under ideal listening con- ditions. AUDIO SYSTEMS & DESIGN, 5421 South 84th St., Lincoln, Nebraska 68516 (402) 489-9888. RADIO PROGRAMS 1930-1962 RADIO PROGRAMS, Reels, $1 00 hour! Cassettes, $1.00 show' Mammoth catalog $1.25. AM TREARENT RADIO SHOWS - Make your own copies or just listen. Great way to build your collection reasonably. Catalog $1 refundable. OTR Rental, Box 465. Livermore, Ca. 94550 YESTERDAY'S RADIO PROGRAMS ON TAPE. Reels, cassettes - fast reliable service. Catalog $1.00 refundable with first order. ADVENTURES. 1301-A North Park Avenue, Inglewood, California 90302. RENT OLD RADIO PROGRAMS as low as 50c per reel GOOD OLD RADIO P.O. Radio Lone Pine, Calif. 93545 OLD RADIO PROGRAMS ON TAPE. Thousands available. Low prices, finest quality, immediate service. Catalogue 25c. Nostalgic Radio, Box 29K, Peoria, II. 61601. RADIO AS IT WAS Reel, Cassette, - Rag time, Honky-Took, etc. others. Custom discs. Our package or recorded to your order from our library. Sample cassette and Cartridge, list $1.25, Refundable. Nostalgic Enterprises, St. Louis, Mo. P.O. Box 3786, 63122. OLD TIME RADIO PROGRAMS on cassette. Catalog $1.00. MB/JB Enterprises, Box 724, Spencer, Iowa 51301. GOLDEN AGE RADIO - your hest source for radio tapes. Box 25215-0, Portland, Oregon 97225. OLD RADIO LIVES AGAIN! Catalog with big selection available for $1.00. R.R. Schurch, 9370 Urban Dr., La Mesa, Calif. 92041. SPEAKERS SAVE 50%. Construct speakers and save money. Send for free catalog and instructions. Speaker Kit, Box 12A, Menomonie, WI 54751. MUSICAL SPEAKERS REPAIRED ALTEC WARRANTY STATION Hughes Electronics Service 45 Dunn St., Asheville, N.C. 28806 AUTHORS, BOOKS PUBLISH your book! Join our successful authors: All subjects invited. Send for free appraisal and detailed booklet. Carlton Press (Dept. VRX) 84 Fifth Avenue, New York 10011. AUDIO DECEMBER, www.americanradiohistory.com AmericanRadioHistory.Com . week. MICHIGAN AUDIOPHILES, visit our new location featuring the area's widest selection of state-of-the-art components. See our transcriptors display with the all glass enclosed SKELETON turntable. Hear the difference in the VESTIGAL 114 . Md. 21228. Marantz 9 amplifiers rack mount. Excellent condition, Ken wood KF-8011 multi -band dynamic noise filter. (617) 3582254. among the very best. A.C. Recording & Electronics, EXCELLENCE WE OFFER: Infinity, Philips, Ortofon, ESS. Revox, Fulton, Sennheiser, SURES, Box 192 AU, Babylon, New York 11702. STEREOPUS-the new equipment review quarterly. Brings you in-depth, realistic reviews on the latest in the world of components. If you are in the future don't be class) $12.00 foreign. Walton Beach, Florida tem, or will sell components individually. (516) 799-0611. year old, mint $625. a PIONEER AMFM STEREO TUNER with Quad synthesizer and Koss Phase 2 headphones. Like new, bought this year. Will sell for best offer. Also includes 4 Allegro speakers, also like new. Must sell immediately. Patnaude, RFD 2, Boxford, SAE Mark IVCM power amp, SAE Mark IX preamp, 2 RTR400E speakers, Toshiba SR -50 turntable. Best offer for sys- 1 source for truly superior audiophile products. Accurate advice, unsurpassed service, and incomparable components from: THE SOURCE, Box A512-2, c/o Audio, 401 At last 6-14 NOISE REDUCTION 943-1044. IN 10A's, 4 months old, original cartons, war- $630. (212) 376-4842. - cabinets, both mint TRANSCRIPTOR SKELETON TURNTABLES and AL tone -arms are alive and doing well. Transcriptor, of the comprehensive state-of-the-art components from: The Stereo Emporium, 3407 Delaware Ave., N.Y. 14217. CROWN SX822 Deck. 7á - 15 ips, $1200; D150 Amplifier, $30U; bo i units 6 months old with WARRANTY & CARTONS; Gary Davison, 128 West End Ave., Binghamton, N.Y. 13905; (607) 729-2064 ranty cards, as new Mk 1M preamp, Mk 27 double band octave equalizer, - $765.00. TEAC 5300 with dust cover and remote control - $575.00. DBX 124 compressor-expander - $265.00. (518) 783-6890. SAE FOR SALE TRADE IN YOUR KLH 9's, QUADS, AND MAGNEPLANARS. The incomparable Fulton J speakers are available. Place your order now. We recommend: Paoli tube amplifiers, Paoli SP3A-1 modifications, Denon moving coil cartridges, Decca's new record care system, KEF 8104 speakers, LinnSondek, Transcriptors Skeleton turntable with vestigal arm, and the new, more comfortable Stax earspeakers. Quality equipment in all price ranges. Trade-ins accepted. Contact us 1975 RECORDS SOUNDTRACKS/OC, JAll/PERSONALITY 3700 Santa Ana, California 92704. NEWSLETTER! RTSA. S. - Plaza Drive. Bldg TAPE RECORDINGS FREE F/211, QUADRAPHONIC RECORDS AND TAPES - World's largest selection - all labels, over 1000 titles - at discount prices! For your free illustrated quad catalog, write: SOUND CONCEPTS, 2713 West Radan, Dept. C12 Peoria, Illinois 61604. CONSUMERS 55343. available. Satisfaction guaranteed. Send $3.00 to: FSC 219 E. 17th St. Bloomington, Indiana 47401. EVERYTHING ON OPEN REEL! Prerecorded classical/popular tapes. Latest releases. Dolby Quad, 96 -page catalogue S1. Barclay -Crocker, Room 857A, 11 Broadway, NYC 10004 AMBIPHON'S RECORDS AND TAPES - Quad and sterHighest quality available anywhere! Send stamped, addressed envelope to: Ambiphon Records, Dept. A, P.O. Box 341, Kingsbridge Station, Bronx, New York 10463. eo. SHOW ALBUMS -Rare. Out of Print LP's. 52 page list 50c Broadway/Hollywood Recordings Georgetown, Conn. 06829. Phone (203) 544-8288. 5,000,000 SURPLUS Records, Tapes -100 new LP's major labels $65.00. 60 8 -track prerecorded, all major labels $90.00; 40 prerecorded cassettes, major labels, new $50.00; 25 open reel prerecorded, all major labels, new $49.50. Catralogue available $1.00 refundable with first order. Surplus Records & Tapes, Box 496, Lone Pine, SOMETHING NEW! A sure cure for nostalgia. Just out! Cassette Tapes played by 'The Versatile Strings" 1. "Souvenirs of Your Old Favorites" With unequalled accoustically pure instrumentation. A Gibson Mandola and Lyon & Healy Guitar. A beautiful sound. Twenty four (24) selections, many with a romantic Calif. 93545. Latin - PERFECTLY CLEAR"' ultra hi-fi record Burwen Laboratories BL -2. The East Bay City Jazz Band Big Bear Stomp. Oriental Strut. Louis-i -an -i -a Blues My Naughty Sweeties Gives to Me. Dans Le rue d'Antibes, etc. $10.50 each postpaid $70.00 postpaid in lots of 10. Send check or money order Massachusetts residents add 3 sales tax Dealers wanted. Burwen Laboratories Inc. 209 Middlesex Turnpike, Bur- lington, Massachusetts 01803 617-273-1488. SOLD @ AUCTION: COLLECTORS RECORDS, LP's; Jazz, Soundtracks, Personalities, Original Casts, Country/Western, Blues, Indicate which list from: Ray Macknic, (or) Theó s, P.O. Box 7511, Van Nuys, Calif. 91406. FREE 200 -PAGE CATALOG. 1,400 New Stereo Recordings. Renaissance, Baroque, Classical, Romantic, Modern Music. Not sold in stores. Not listed in Schwann's. Highest quality! Budget label prices! Available only by mail. MUSICAL HERITAGE SOCIETY, Box 932 AU, New York, N.Y. OLDIES - 45 RPM Original hits. Catalog 50c C&S Record lilt - one hour. - P.O. Box 890 Baldwin Park, CA 91706 California residents add 6% sales tax. SHORTWAVE HEAR POLICE FIRE Dispatchers. Catalogs show receivers; exclusive directories of "confidential" channels. Send '10c stamp. Communications, Box 56AU, Commack, New York 11725. SITUATION WANTED FORMER DJ would like to return to radio in a similar position or as a Program Director. have a third class broadcast endorsed license, 2 years college, 2 years experience. Contact: Doug Galliher, 3907 Angol Place, Jacksonville, Florida We recommend components and systems CUSTOM RECORDING SERVICE, Tapes, discs, and casStereo and mono. Live and copies. Editing. Masters and pressings. High quality at reasonable rates. settes. Joseph GLiovanelli, Audio -Tech 32210. (904) 771-7386. PRODUCTION -CUSTOM REPRODUCTION 8 -Track, cassette & Reel to Reel. We specialize in corporate meetings. Call or write T.S. Recordingc/o T.C. Shearer, 385 Ocean Blvd., Suite 5C, Long Branch, N.J.07740, (201) 870- 2952. - - - COMPLETE CUSTOM RECORDING SERVICE Record pressing, cassette duplication editing location recording. Omega Audio, 25520 Graham. Detroit, Mich, 48239. source to Maxell UD tapes & cassettes at amazingly low prices. DBX. Dolby available. Box 3065, Seattle, Washington 98114. THE NEW YORK AUDIO SOCIETY INC, is a unique, non- profit, member supported hi-fi club featuring interesting monthly meetings about sound and the latest audio techniques. We invite all N.Y. area audiophiles to attend one of sessions as our guest. Details about meetings and membership available. Write Box 5889 Grand Central P.O.; N.Y.C. 10017. Call 212-722-2781. these STEREO MASTERS, RECORDS AND ALBUMS. Check our prices. Newest type high level cutting equipment featuring: Neumann VMS 70 Computer control lathe, Parametric Equalization, Dolby, DBX, and the new SX74 Cutting System by Neumann. Special package prices on pure vinyl album and single record production. 1000 45 RPM stereo singles $273.00 including mastering. 100 LP albums $436.00 including printed jackets. Write or call for brochure. A & R Record Manufacturing Corp., 902 N. Industrial Blvd., Dallas, Texas 75207. (214) 741-2027, SONGWRITERS Present your songs to publishers like professionals. By mail get the right business contacts. Write for this valuable and Discontinued, 216 N. Rose, Burbank, California 91505. informative booklet. Send $3.00 to: SUNSOUND 256 Robertson, Dept. 1558 Beverly Hills, Ca. 90211 S. Lutsky, UP TO 60% DISCOUNT. Name brand instruments. Catalog. Freeport Music, 455R Route 110, Melville. N.Y. 11746. CATALOGS. Broadcasts, soundtracks. Personalities of Thirties, Forties. Box 225, New York, N.Y. 10028 40% DISCOUNTS. Huge Stock of Name Brand Instruments. Free Catalog. Gracin's 110 Dept. A, 606 Route 110, Huntington, N.Y. 11746. Maher, WHOLESALE Musical Instruments, accessories. Allied, 573, Route 17, Paramus, N.J. 07652. house, P.O. Box 8057, Pensacola, Florida 32505. FILM -STAGE SOUNDTRACKS. Large free list. P.O. Box 557342, Miami, Fla. 33155. A. COLLECTORS 45's originals, good to mint. Send want list SASE. Buffalo Records, P.O. Box 398, Kirkland, Ill. and 60146. WANTED: Albums, EP's. 45's, radio shows, transcription discs by Percy Faith; albums by Warren Barker, Clare Fischer, George Shearing. AUDIO magazines from 50's and early 60's. Bill Halvorsen, 646 Azalea Drive, Rockville, MD 20850 Rare 78's. State Category. Record lists, 3238 Stoddard, San Bernardino, CA 92405. - 5th Ave., San NEW HI FI RECORD FLOATING DOWN TO COTTON TOWN Babson College Dixieland Band - Babson Label. Recorded at Burwen Studios -Sugar Foot Stomp, Darktown Strutters Ball, Floatin Down to Cotton Town, Your Feet is Too Big, Wolverine Blues, etc. Still Available: PERFECTLY CLEAR BL -2, THE EAST BAY CITY Big Bear Stomp, Blues My Naughty Sweetie JAll BAND Gives to Me, Dan Le rue d'Antibes, etc. $10.50 each, $70.00 package of 10, postpaid. Massachusetts residents add 3% sales tax. BURWEN LABORATORIES, 209 Middlesex Turnpike. Burlington, Mass, 01803. - AUDIO - MASS or in person, find out the correct way. Also find out where to MUSICAL INSTRUMENTS WHILE YOU WERE LOOKING for out -of -print records, you CLASSICAL LPs bought -sold. Junker, 705 Francisco, Ca. 94118. 2819 Laboratories. Newkirk Ave., Brooklyn, N.Y. IN9-7134. I Sales. Box 197, Wampsville, N.Y. 13163. should've been looking for us. - and mate your needs and budget to the best performance ULTIMATE DUPLICATION (10 up) from your program "The Good Old Happy Sounds" Banjo and Guitar. A moving and joyous sound. Twenty two (22) selections one hour. Two hours of good listening pleasure. Price: $4.95 per Cassette ea. or $8.95 for both. Postage paid. Send check or money order to: Reilly Records 2. 10023. RECORD COLLECTORS' CONTACT GUIDE. Dealers. magazines, societies, Handbooks and directories listed. $3.00. Jackson, 1506 W. Barker, Peoria, II. 61606. SERVICES RENT Open Reel or Cassette Prerecorded tape. All labels. Catalog $1.00. Tape & Time, P.O. Box 740, Hopkins, Minn, $300-$1200 off Music, Box 88, E. synthesizer CASK FOR PHOTOS. Report tells how and where. Send only Si for booklet 'P54' to Dayspring, 560 Lake Dr., Box 292. Owosso, MI 48867. TELEPHONE ANSWERING EQUIPMENT - below wholesale. All brand DICTAPHONE-ANSAFONE in original cartons. Model 520, $200: Model 610, $145; Model 640, $275; Model 1700, $825. E.B.L.. (212) 377-8424 (24 Hrs.) 94563. 655 Sixth Avenue, New York, 212-CH3-4812 concept -features PHOTOGRAPHY Evans Place, Orinda, Calif. HIGH FIDELITY SPEAKERS REPAIRED AMPRITE SPEAKERS SERVICE new pianos & organs. Catalogue, Liberty Weymouth, Mass. 02189. 16mm SOUND Features, Shorts, New, Used for Sale. Free Catalog. National Cinema, 333 W. 57th St., N.Y., N.Y. 10019. 5 DON'T PAY the high mail order prices. Thieves Warehouse is coming to your area. Franchises available. Thieves Ware- on universal compatibility, modular construction. For complete information send SASE or 25c to: CFR ASSOCIATES, P08 F, Newton, NH 03858. EM TAPE RECORDER HEADS brought back to spec. Wear removed. Brilliant finish. $10.00 each. One day service. E. N.Y. 10010 NASHVILLE RECORD PRODUCTIONS WILL PRESS HIGH QUALITY PURE VINYL RECORDS FROM YOUR TAPES. SEND FOR SAMPLE RECORD AND PRICE LIST. ALSO FINEST DISC 469 Chestnut MASTERING. St., NASHVILLE TENNESSEE 37210. CANVAS PHOTO TOTE BAG. Your favorite color or BW picture. We'll blow it up in full color on our 12x14 canvas tote bag. Send $2.50 for catalog and price list. Refundable with your first order. Write to: Giensova Marketing Assn., P.O. Box 4991, Washington, D.C. 20008. DYNACO COMPONENTS assembled. Lowest prices. Guaranteed fully. Box A512-3, C Audio. possible REAL ESTATE new DECEMBER, 1975 ONE VACANT GARAGE for rent -Daily rates also. W. - 76 Street, Brooklyn, N.Y. 11209. E. Anderson, 401 115 www.americanradiohistory.com AmericanRadioHistory.Com AUTO ACCESSORIES TOP PRICES PAID for all Lionel trains, any condition. Call today. (212) 833-8920. SANDBLASTERS - $39.50-$839.50. Free Catalog. Truman, 1330A Market, Youngstown, Ohio 44507. WANTED-"LUX" OR "LUXMAN" tube stereo power amplifier and tube stereo preamplifier. Any reasonable price or condition. Please contact immediately Box 1159, New Rochelle. N.Y. 10805. - 1,000 Different parts. Catalog $1.00. Clark's Corvair Parts, Shelburne Falls, MA 01370 CORVAIR Parts TAPE & TAPE RECORDERS INSTRUCTION & EDUCATION DIGITAL ELECTRONICS! Design and understand Digital SCOTCH RECORDING TAPE, lowest prices TAPE CENTER Box 43058, Washington, D.C. 20012. Circuits. Increase technical competence. Complete and guaranteed course is highly effective. $10.00. Free literature. DYNASIGN, Box 60AM, Wayland, Mass. 01778. SCOTCH, CAPITOL. Blank cassettes, cartridges, reels. Discount prices. Lawson's. Box 510, Livermore, CA 94550 PROFESSIONAL HI-FI COURSE -Instructors include Len Feldman, Julian Hirsch, Larry Klein. and Larry Zide. Home study course also available. Send $1.00 for audio primer and full information or visit HI -Fl EXPO, 393 5th Ave., New York City 10016. RECORDING TAPE: Custom Loaded, 8 track, reel, cassette. Prices on request. DICK WALEN, 4226 Robert St., Red Wing, Minn. 55066 TDK. BASF, Memorex, Maxell, cassettes, reels, 8 -tracks. Lowest Prices, Guranteed, New. S&S Audio P.O. Box 56039 Workshop, Department 503FK, Hewlett, New York 11557. Harwood Heights, 60656 II. EQUIPMENT WANTED MCINTOSH 275. Call collect (313) 331-0453. NOW AVAILABLE FAMOUS REFLECTING SYSTEM'S 41/2" REPLACEMENT DRIVERS. 57.98 POSTPAID. BIG QUANTITY DISCOUNTS, FREE SPECIFICATIONS, AURATONE, BOX 580-26, DEL MAR, CALIFORNIA 92014. NEED ACRO 300 Ultra Linear Output transformer new or good condition. Will pay fair price. Maathuis, 510 16th St., Ogden, Utah 84404. WE MUST HAVE YOUR USED COMPONENTS Premium Trade or Cash for: McIntosh C22/24, MC75/225/240/275. Maranta 7C/T, 8B, 9B, 10B. J.B.L. SA -600/660, Metregon, Minigon, Harts field, L-101. Music & Sound Ltd.. 111/2 Old York Rd., Willow Grove, Pa. 19090. (215) 659-9251. WANT TO BUY Revox-A77 Deck, used but good condition. Will pay up to $500. Tom Stone, 130 East 18th Street, Apt. 2-U, New York, N.Y. 10003. (212) 777-2029. WANTED: Reel to Reel Tape Deck, Cassette tape deck with speakers and headphones by Soundesign. Write: Hubert Woods, 162 Curry Court, Talladega. Al. 35160. a FREE Pa. 19107. experienced -stock boy/delivery Apply in person or call 212 -SH. 8-8920. MALE/FEMALE AUDIO ENGINEER WANT AO in AUDI- Box 821, Stratford, Con- BUSINESS INVESTIGATOR DISCLOSES jealously guarded mail order trade secrets. Helps beginners make $600.00 weekly. Giant free report! Futuronics, 1311 Berkshire, Austin, Texas 78723. envelopes. Nothing to buy or sell. Circulars supplied free! Rush stamped addressed envelope to: K. Heinrich, Box 123-SAJ, Hayes Center, NB. 69032. $500/1000 stuffing - - Stuffing, mailing circulars for $100 WEEKLY POSSIBLE Send stampadvertisers. Home - spare time. Information ed envelope. Opportunities, Box 721 - A0, Lynbrook, N.Y. 11563. -- NEED ACRO TO-330 output transformer. State condition and price. Chris Hood, 11 E. Prospect Ave.. Pittsburgh, Pa. Rush stamped envelope. Receive $12.95 orders. Details Distributors, Box 9 AO, East Rockaway, N.Y. 11518 CANADIANS! Mailing. Keep $8.00 profit. RECORDS. DISCOTHEQUES ARE IN. COMPLETE DETAILS, DOS, DON'TS, PHOTOS, DESCRIPTIONS, ETC. SEND $5.00 TO "DYNAMIC UNO," P.O. Box 8116 CORPUS CHRISTI, TEXAS 78412. EARN PANASONIC CALCUTTA Portable Stereo Phonograph with FM/AM Radio. Stereo eye and stereo muting. Model No. SG 650. 6'/" PM speakers. L. Oakes. Beaven Kelly Home, Holyoke, Mass. 01040. $100.00 NIGHTLY PLAYING UNIQUE COLLECTION TECHNIQUE for business with pastdue accounts. Rush $1 for free guide. Raymond Fry, 1702 S. 91761. Looking for Quad ES speakers (2), also McIntosh MPI-3. Reply, stating price, condition and serial numbers to Phillips, Welland St. N., Thorold, Ontario, Canada L2V 2B8. Palm. Ontario, CA. LP's -"Odessa" & "Cucumber WANTED Castle" by the Bee Gees. Near new condition. Wm. J. Riese, 3429 S. Nude Way, Aurora, Colo. 80013. $25.00 SOUNDCRAFTSMEN preamp or SAE preamp and/or Soundcraftsmen equalizer. 7302 Forest Rd., No. 304, Landover, Md. 20785. CANADIAN DEALER looking for American or British trade connections willing to work on cost plus basis (for cash quantity purchase) on closeouts and regular stock. Interested WANTED: McINTOSH 75 mono amplifier. Melvin Robinson, 214 W. 15th St., Cincinnati, Ohio 45210. JBL, Thorens, Shure, BASF, TDK, Scotch, Watts, Maranta, etc. Replies held confidential. Electronic Shoppers World, 278 Havelock, Toronto, M6H 3B9. 1 - WANTED: HARMON KARDON Citation A preamp. Also need volume control for Citation A. J. P. Sammut, 432 Chestnut Ave., San Bruno, Calif. 94066. Wanted: Surplus marclmedisu and components. Sheldon Richman, buyer. Richman Sales Co., 3321 Columbia, Lincolnwood, III. 60645 (312) 679-4851. BS or equivalent. Experienced in de- sign of solid state professional broadcast and recording systems. Ability to work with customers. Opportunity for ad- vancement in growing company. Send resume, including salary requirements to Robins/Fairchild, 75 Austin Blvd., Commack, N.Y. 11725. COMMUNICATION EQUIPMENT - - - HAM Buy Below CB MARINE SCANNERS Wholesale. Save up to 50%. Buy Direct From Factory Warehouse. Guaranteed Lowest Prices Anywhere. Catalog $1.00: WHITLOCK INTERNATIONAL, P.O. Box 131, Wayne. Mich- PLANS & KITS CONSTRUCT YOUR OWN speaker enclosure. Send $2.00 for drawing to: Creightney Sounds. 140-25 169th Street, Jamaica, N.Y. 11434. TOUCHING MACHINE Listen to music through your skin with the amazing patented Sonic Stimulator. Feel a concert of pleasure anywhere it touches you. Send for free literature. AU DITAC BUSINESS OPPORTUNITIES DO SIMPLE ADDRESSING 15205. - clerk. 1940 Washington necticut 06497 RECORDS in confidence, to Frank Nemeyer, North American Publishing. 401 No. Broad St.. Philadelphia, igan 48184 DYNAKITS, IAD, lowest prices, Underground HI-FI Sales, 324 Broadwater Road, Arnold, Md. 21012. (301) 647-0919. $4/12 with salary requirements, HIGH FIDELITY CASH FOR Mint Ips & prerecorded reel tapes. Records, Box 323, Hillburn, New York 10931. OMART today! SUBSCRIBE! AUDIO IS EXPANDING its editorial staff and is seeking knowledgable audiophile with editing and writing experience. Must be good writer and have magazine production experience. Position is in head office in Philadelphia. Send resume SCOTCH AND MAXELL TAPE DISCOUNTED. Write and Save. N.A.B. Audio, Box 7. Ottawa, IL 61350 FREE EDUCATIONAL ELECTRONICS CATALOG. Edukits WANT SOMETHING? Place HELP WANTED EQUIPMENT WANTED Business loans; 20 sources $2.00. N&N, Box 3483-A Temple, Texas 76501. DAILY POSSIBLE: Addressing-stuffing enve- lopes. Typing/longhand. Details -Rush stamped envelope. Elite. Box 715-A0, Lynbrook, N.Y. 11563. 94109 (415) 775-7061 San Francisco HELP! Anytime you have a question about your Audio subscription, please include a mailing label to in- AFFIX LABEL sure prompt service on your inquiry. HERE CHANGE OF ADDRESS If you're about to move, please let us know approximately four weeks before the move comes --__/ about. Or, if there is anything wrong with your current mailing label, please let us know on this form also. Simply affix your present label here, and carefully print the updated information below. PLEASE HELP US TO SERVE YOU BETTER AUDIO MAGAZINE 401 N. Broad Street Phila., Pa. 19108 Name GOVT. SURPLUS MANUALS for Gov't. Surplus Radios, Test Sets, Scopes. List 50c Books. 7218 Roanne Drive, Washington, D.C. 20021 (Please Print) Company Address City State AUDIO 116 www.americanradiohistory.com AmericanRadioHistory.Com _dip DECEMBER, 1975 Continued from page 107 Annual Index out of the violas and celli in the Walker piece. The second album is unabashedly contemporary in sound and method. Oily Wilson's Akwan (1974) uses a Fender -Rhodes electric piano and amplified strings, though it is not technically an electronic composition. Nevertheless, the interplay among the trombones near the beginning, the manner in which percussion and the Fender -Rhodes are employed, and the overall abstraction of the piece give it a distinct electronic -music flavor (particularly of the tape -with -orchestra variety). Wilson uses novel voicings (especially in the brass), dis- plays a highly developed con- Subject Index AM Radio Quality AM Radio, George McKay, Jan., 28. Amplifiers Bi -Amplification, John M. Lovda and Stephen Muchow, Sept., 20. sciousness of rhythm/arhythm, and has a masterful sense of timing which allows him to extend an idea until just Power FETs, Bascom H. King, Feb., 42. Transient IM Distortion, W. Marshall before the moment monotony would set it. Akwan is, to my ears, a major work, one which will be heard and discussed often in the future. T. J. Anderson's Squares (1965) involves such things as symmetries of fragmented phrases, overlapping tone -color "platforms," and the like. What would seem on paper a disjointed collection of disparate ideas, sounds quite unified, thanks to the ingenuity of Anderson's systems of grouping. Though it is an atonal, essentially themeless work, it is no doubt the kind of indisputably con- Cassette Decks: How Well Do They Stack Up, George W. Tillett, Sept., 38. nonetheless appeal to musical conservatives, if only because the pieces fit together into such a neat, accessible bundle. Talib Rasul Hakim may be an unfamiliar name because the composer first attracted attention as Stephen Chambers. Visions of Ishwara (1970) is an esoteric and stately work, which begins and ends with an exotic alto Directories Annual Product Directory, October. Addenda, December, 77. Directory of Manufacturers, Oct., 30 Amplifiers, 36; Cassette and Cartridge Tape Decks, 72; Equalizers, 105; Headphones, 102; Loudspeaker Systems, 76; Microphones, 106; Multi Play Turntables, 58; Open -Reel Tape Decks, 68; Phono Cartridges, 64; Preamplifiers, 44; Receivers, 52; Single Play Turntables and Tonearms, 60; temporary composition that will flute line over a ceremonial -processional bass drum pulse. The trombone, tuba, and percussion parts are seemingly derived from Tibetan ritual music, with the rest of the orchestra arranged so that each group of instruments seems to seek its own level at random. The effect is not unlike a Sun Ra improvised ensemble, translated into orchestral -block terms. Visions is a very impressive composition, which should help the composer retain his reputation under his new name. It's always difficult to judge the performance of a new and complex composition without access to the score (and sometimes even with the score), but all three works seem to have received tour -de -force realizations by Freeman and Richard Bunger, soloist Tom Bingham on Akwan. Sound: A Performance: A AUDIO DECEMBER, 1975 Leach, Feb., 34. Craig 3139 Car Radio, July, 25; addenda, Oct., 20. Crown VFX/2 Crossover/Filter, Dec., 69. Dynaco 400 Basic Amplifier, May, 46. ELAC 760 Automatic Turntable, Aug., 62. Elekt-O-Fonie FU -100 Receiver, Apr., 54. One Basic Amplifier, Nov., 66. Ferrograph Super Seven Open -Reel Tape Deck, Mar., 42. Fisher ST -425 Speaker System, Jan., 48. EPI GAS Ampzilla Basic Amplifier, Sept., 57. Christmas Buying Guide, Nov., 54. Heath AR -2020 Receiver, June, 48. Hitachi HS -300 Speaker System, Mar., Construction Articles Build an Audio Generator, M. J. Salvati, Oct., 22. Build A Dynamic Noise Suppressor, Maxwell S. Strange, June, 34. 46. J.I.L. 605 Car Radio, July, 26. JVC 4VR-5426X Receiver, Aug., 47. Crossword Puzzle, Aug., 38. Kensonic C-200 Control Amplifier, P-300 Basic Amplifier, Mar., 49. Kenwood KP-5022 Turntable, Sept., 65. Kenwood KX-710 Cassette Deck, Apr., dBs Made Simple, Herman Burstein, Jan., 36 Tuners, 48. Car Speakers Directory, July, 18. Car Stereo Radio/Tape Player Directory, July, 13. Car Stereo Radio/Tape Player Manufacturers, July, 12. Equipment Profiles Ace Audio ZDP Preamplifier, April, 60. ADS 2001 Car Speaker System, July, 36. AKAI GX-400D-SS Open -Reel Tape Deck, Feb., 56. Avid 102 Speaker System, Sept., 62. Becker Mexico Car Radio, July, 25. B&O BE -2200 Cassette Deck, Aug., 67. BGW 500D Basic Amplifier, Dec., 76. C/M Laboratories, RR -805 Receiver, June, 54. 65. Koss HV/1A Headphones, Dec., 68. Marantz 125 Tuner, Feb., 54. Nakamichi 500 Cassette Deck, Nov., 62. Nakamichi Large Reference Monitor Speaker System, Dec., 72. Panasonic CQ-999 Car Radio, July, 28. Phase Linear 4000 Preamplifier, Nov., 58. Philips RH -532 Speaker System, Apr., 67. Pickering XUV/4500Q Phono Cartridge, Nov., 71. Pioneer KP -301 Car Radio, July, 30. Pioneer CT -F7171 Cassette Deck, Nov., 72. Polk Nine Speaker System, May, 36. Radio Shack STA -225 Receiver, Dec., 46. SAE Mk IIICM Basic Amplifier, Jan., 61; Addendum, Aug., 69. Sansui 881 Receiver, Apr., 55. Scott R77S Receiver, May, 32. Sharp RT -480U Cassette Recorder Addendum, Jan., 65. Sherwood 7210 Receiver, July, 34. Shure M-64 Preamplifier, Feb., 61. Sony TC -755 Open -Reel Tape Deck, Sept., 67. Soundcraftsmen PE -2217 Equalizer, Mar., 36. Supex SD -900/E Phono Cartridge, Sept., 60. 117 Sylvania AS -210A Speaker System, Aug., 63. Technics by Panasonic RS -676 Cassette Deck, May, 72. Technics by Panasonic T-400 Speaker System, Dec., 54. Technics by Panasonic SA -8500X Receiver, Mar., 31. Wollensak 8080 8 -track Cartridge Deck, Aug., 52. Yamaha B-1 Basic Amplifier, Aug., 56. Yamaha CR -1000 Receiver, Jan., 44. Yamaha CT -7000 Tuner, Dec., 64. Yamaha YP-701 Automatic Turntable, June, 52. Basics of Turntables, David L. Joseph- son, June, 26. Adoption the Westrex 45/45 System, Ralph W. Wight, Mar., 24. of Author Index Bingham, Tom, The Many Worlds of Sun Ra, March, 56. Blacker, George, Home Recording Through the Years, April, 28. Burstein, Herman, dBs Made Simple, Jan., 36. Clifford, Martin, Language of High FTC Ruling On Amplifiers FTC Wattage Ratings: An Optimistic View, Brian Wachner, Feb., 22. FTC Wattage Ratings: An Alternative View, Robert Tucker, Feb., 30. How Valid is the FTC Preconditioning Rule?, Joseph DeMarinis, Sept., 30. Headphones Dual Impedance Headphone Circuit, D. A. Kerr, May, 24. Piezoelectric Principle in Headphones, Martin Clifford, May, 28. Language of High Fidelity, Part XIII, Martin Clifford, Dec., 38. Miking With The Three -Point System, Dec., 28. Quadraphony What Do You Really Hear in Quadraphony?, Daniel Shanefield, Nov., 44. Up -Date: Musings on the Four -Channel Scene, George W. Tillett, Nov., 36. Record Cleaners -Do They Really Work? B. V. Pisha, Mar., 20. Fi- delity, Dec., 38; Piezoelectric Principle in Headphones, May, 28. and G. R. Lewis, Earthquake Sound System, April, 46. Davis, Carolyn P., Syn-Aud-Con: Audio Toolmaker, Sept., 54. DeMarinis, Joseph, How Valid is the FTC Preconditioning Rule?, Sept., Czerwinski, C. J. 30. Feldman, Leonard, Five Car Radios Tested, July, 24. Heyser, Richard C., Speaker Tests -Polar Response, May, 30; Room Tests, Jan., 66. Josephson, David L., Basics of Turntables, June, 26. Kempler, Joseph, Making Tape, April, 38. Kerr, D. A., Dual Impedance Headphone Circuit, May, 24. King, Bascom H., Power FETs, Feb., 34. Leach, W. Marshall, Transient IM Dis- tortion, Feb., STATEMENT OF OWNERSHIP, MANAGEMENT AND CIRCULATION, Act of August 12, 1970; Section 3685, Title 39, United States Code. 1. Date of Filing, September 15, 1975, 2. Title of Publication, AUDIO; 3. Frequency of Issue, Monthly; 4. Location of Known Office of Publication, 134 N. 13th Street, Philadelphia, Penna. 19107; 5. Location of the Headquarters or General Business Offices of The Publishers, 134 N. 13th Street, Philadelphia, Penna. 19107. 6. Names and Addresses of Publisher, Editor, and Managing Editor: Publisher, Jay L. Butler, 134 N. 13th Street, Philadelphia, Penna. 19107; Editor, Eugene Pitts Ill, 134 N. 13th Street, Philadelphia, Penna. 19107; Managing Editor, none. Owner, North American Publishing Company, 13th Street, Philadelphia, Penna. 19107. I.J. Borowsky, 134 N. 13th Street, Philadelphia, Penna. 19107. 8. Known Bondholders, Mortgagees, and Other Security Holders Owning or Holding 1 Percent or More of Total Amount of Bonds, Mortgages or Other Securities: 7. 134 N. None. 9. Paragraphs 7 and 8 include, in cases where the stockholder or security holder appears upon the books of the company as trustee or in any other fiduciary relation, the name of the person or corporation for whom such trustee is acting, also the statements in th,. two paragraphs show the affiant's full knowledge and belief as to the circumstances and conditions under which stockholders and security holders who do not appear upon the books of the company as trustees, hold stock and securities in a capacity other than that of a bona -fide owner. Names and addresses of individuals who are stockholders of a corporation which itself is a stockholder or holder of bonds, mortgages, or other securities of the publishing corporation have been included in paragraphs 7 and 8 when the interests of such individuals are equivalent to 1 percent or more of the total amount of the stock or securities of the publishing corporation. 10. This item must be completed for all publications except those which do not carry advertising other than the publisher's own and which are named in Sections 132,231, 132,232 and 132,233. Postal Manual (Sections 4355a, 4355b, and 4356 of Title 39, United States Code). Average no. copies each 34. Lewis, G. R., and C. J. Czerwinski, Earthquake Sound System, April, 46. Lovda, John M. and Stephen Much ow, Bi-Amplification, Sept., 20. McKay, George, Quality AM Radio, during Single issue preceding nearest to filing date 12 months issue A. Total no. copies printed (Net Press Run) B. Paid Jan., 28. Loudspeaker Systems Earthquake Sound System, C. J. Czerwinski and G. R. Lewis, Apr., 46. Motional Feedback in Loudspeaker Systems, George W. Tillett, Aug., 40. Speaker Tests, Richard C. Heyser; Polar Response, May, 30; Room Test, Jan., 66. A. N. Thiele -Sage of Vented Speakers, Ray J. Newman, Aug., 30. at Home Through Years, George Blacker, Apr., 28. Recording Sun Ra, The Many Worlds of, the Tom Bingham, Mar., 56. Syn-Aud-Con-Audio Toolmaker, Carolyn P. Davis, Sept., 54. Making Tape, Joseph Kempler, Apr., 38. 118 1. 125,025 carriers, street vendors Muchow, Stephen, and John M. Lovda, Bi -Amplification, Sept., 20. Newman, Ray J., A. N. Thiele -Sage of Vented Speakers, Aug., 30. Pisha, B. V., Record Cleaners -Do They Really Work?, March, 20. Salvati, M. J., Build an Audio Generator, Oct., 22. Strange, Maxwell G., Build a Dynamic Noise Supressor, June, 34. Tillet, George W., Cassette Decks, How Well Do They Stack Up?, Sept., 38; Motional Feedback in Loudspeakers, Aug., 40; Up -Date: Musings on the Four Channel Scene, Nov., 36. Tucker, Robert, FTC Wattage Ratings: An Alternative View, Feb., 30. Wachner, Brian, FTC Wattage Ratings: An Optimistic View, Feb., 22. Wight, Ralph W., Adoption of the Westrex 45/45 System, March, 24. 123,570 circulation Sales through dealers and and counter sales 24,444 Mail Subscriptions Total paid circulation Free Distribution by Mail, Carrier or other means C. D. 1. E. 101,965 4,828 5,597 F. 106,793 108,554 1,009 1,071 G 15,768 15,400 123,570 125,025 Samples, complimentary, and other free copies Total distribution (Sum of C and D) 1. Office use, left -over unaccounted, spoiled after printing 2. Copies distributed to news after printing Total (Sum of E and F should equal net press run - shown in A) 23,539 79,418 102,957 77,521 2. certify that the statements made by me above are correct and complete. I JAY L. BUTLER, Publisher AUDIO DECEMBER, 1975 PROFESSIONALS TALK ABOUT THE NEW MARANTZ TUNER AND AMPS. The Marantz 1070 integrated amp is close to optimum in performance and the low price makes it an even better value: In December, 1974, sound engineers and audiophiles were invited to examine and discuss the new Marantz Stereo Console Amplifiers featuring models 1040 and 1070 and the new Marantz 112 AM/FM Stereo Tuner. The following comments were taken from that taped discussion. "The circuitry is now full complementary direct coupled to the speaker terminals. As a result, the damping factor is much improved at low frequencies where it counts:' The 1070 Stereo Amp "As far as good basic features are concerned, it's comparable to units cost- ing twice as much:' "It maintains al l the features of the Marantz 1060, plus it adds a number of features of its own. For instance, it now has graphic slide -type tone controls, two tape monitors and a versatile mode selector switch:' "With the 1070 you have a full range of tone controls like bass, mid range and treble slide controls plus preamp out and main in jacks:' "I feel strongly about the preamp out jacks. You can re -equalize tape recordings, insert equalizers or even add electronic cross-overs into the chain::' "One major feature that I like in the 1070 is its ambience circuitry. Essentially "The output circuitry now includes a speaker protection relay circuit and turn on delay::' "There's improved thermal stability. This buys long term reliability as well as improved performance:' The 1040 Stereo Amp "The new 1040 integrated amp is rated at 20 watts minimum continuous power per channel with no more than 0.3% total harmonic distortion, 20 Hz to 20 kHz, both channels driven into an 8 ohm load:' "It also has the ambience circuitry for simulated 4 -channel. Most all of the features of the 1070 are on the 1040:' The 112 Tuner "It's got phase lock loop, a Dolby®* de -emphasis switch and a number of other high-performance features. There're no gimmicks in it. Every feature is practical::' "A complete system including the tuner plus either the 1070 integrated amp or the 1040 integrated amp gives performance you couldn't get in most receivers and still costs less than $500:' 112 The Marantz 1070 Amp, 1040 Amp and 112 Tuner are just part of the exciting new Marantz component line starting as low as $199.95. Each of them reflects the kind of technical expertise and engineering excellence that has made Marantz the choice of professionals world-wide. Stop by your local dealer and see the entire Marantz line. Or send for a free catalog. Marantz. Ask an expert. "It's an excellent performance component for a modest price:' it's a speaker matrix or pseudo 4-channel. This means you can get into simulated 4 -channel sound by just adding a second pair of speakers::' "In addition to t he step up in power to 35 watts minimum continuous power per channel with no more than 0.3% total harmonic distortion, 20 Hz to 20 kHz both channels driven into an 8 ohm load, the circuitry is direct coupled:' Super *Dolby System under license from Dolby Laboratories, Inc. ©1975 Marantz Co., Inc., a subsidiary of Superscopc, Inc., 8150 Vineland Ave., Sun Valley, CA 91352. In Europe:without scope Europe, S.A., Brussels, Belgium. In Canada: Superscope Canada, Ltd., Ontario. In the Far East: Marantz Far East, Tokyo, Japan. Prices and models subject to change notice. Consult the Yellow Pages for your nearest Marantz dealer. www.americanradiohistory.com AmericanRadioHistory.Com OnlyTechnics gives you the world's most precise drive system, any way you want it. Direct -drive precision. Now you can have it any way you want it. Because Technics uses direct drive in more kinds of turntables than anyone else. You can get it for under $200 in the SL -1500. One of four manuals. Or for about $500 you can have our professional turntable, the SP-10.There's a fully automatic single play model, the SL-1300. And the world's first direct-drive changer, the SL -1350. And all these turntables share the Technics direct -drive system. A system so superior that FM stations have been using our direct -drive turntables for years. Here's why. In our direct -drive system, the platter'is an extension of the motor shaft. There are no belts or idlers to produce variations in speed. So all our turntables have less than 0.03% wow and flutter (WRMS) (0.04% for the SL-1350). You won't hear any rumble either. Because we use an electronically controlled DC motor that spins at exactly 33 or 45 rpm. And, unlike rumble -producing highspeed motors, our motor introduces so little vibration into the system that any rumble remains inaudible Direct Drive (-70dB DIN B). System And every -Technics direct-drive turntable has variable pitch controls. A built-in stroboscope. And CD -4 phono cables. And for those that include a tone arm you also get viscous damped cueing. Anti -skating. Feedback insulated legs. Even a dust cover and an integral base. But we don't have to tell you how good these turntables are. Read some of the reviews*. And see for yourself. The concept is simple. The execution is precise. The performance is outstanding. The name is Technics. *SP-10-Audio, 8/71; Stereo Review, 9/71; Audio, 10'73.3/74,. SL-1100A-Stereo Review, 7/73; High Fidelity, 9/73. SL-1200 - Radio Electronics, 7/74; Audio, 7/74; Stereo, Fall 74 SL-1300 - FM Guide, 9/74; Stereo Review, 2/75. FOR YOUR TECHNICS DEALER, CALL TOLL FREE 800 447-4700 IN ILLINOIS, 800 322-4400. www.americanradiohistory.com AmericanRadioHistory.Com
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