User manual | Baking with the - American Radio History

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THE AUTHORITATIVE MAGAZINE ABOUT HIGH FIDELITY
DECEMBER 1975
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Baking with the
Three -Point
System
Language
of High Fidelity
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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.
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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
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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.
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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
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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
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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:
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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
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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.
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products
9613 oates
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this new ESS standard
ESS dealer-a dealer
-,:morrow. the ESS Heil
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Hi a ïr- mücra tra ns
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syst
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First there was
vacuum tube amplification
then the solid state transistor
and now...
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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
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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
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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
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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
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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
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DECEMBER, 1975
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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
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1975
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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
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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
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36
AUDIO DECEMBER,
1975
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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
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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
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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
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DECEMBER, 1975
MOM
We're not afraid
to turn our back
on you.
®
SYLVANIA
.n"K."
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Q)
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-(-- %.
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IIMOE
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USING OOMIESIC AND
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"...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
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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
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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
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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
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DECEMBER, 1975
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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
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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
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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.
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I,'11 "III IIII
(DOLBY NR
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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
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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
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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
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60Hz
20
65Hz
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30
Hz
Fig.
2-Complex impedance polar plot.
AUDIO DECEMBER,
54
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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),
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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
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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
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Woodside, New York
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TREBLE
MORANGE
11377
SANSUI AUDIO EUROPE S.A.,
Gardena, Calfornia 90247 SANSUI ELECTRIC CO., LTD., Tokyo, Japan
Antwerp, Belcium In Canada: Electronic Distributors
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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
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Check No. 42 on Reader Service Card
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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.
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Fig.
100
10
r
SPL A2
I
110
Hz
I10Hz
SPL A4=440Hz
I
100
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Fig. 9-Harmonic distortion for the musical tones El or 41
Hz, A2 or 110 Hz, and A4 or 440 Hz.
AUDIO
60
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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
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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
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MILLISECONDS
11-One-meter energy -time response measured on
o
10
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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
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MILLISECONDS
Fig. 12-One-meter energy -time response measured 30 degrees off axis.
Check No. 91 on Reader Service Card
AUDIO DECEMBER,
62
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1975
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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
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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
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AUDIO
64
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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
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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
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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
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10
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STEREO THD =0.077% See
40
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20
3.0
30
50
40
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60
50
70
80
MONO
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10
100
INPUT,"R" OUTPUT
881 8I
S/N' 75dB
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WIDE I.F SETTING
=
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0.5
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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,
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AmericanRadioHistory.Com
1975
NOW... anAUDlO exclusive:
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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1
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±5
35-20
81
50
SR -3
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12
38
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35-20
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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
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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
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REFERENCE NOTES:
(11
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slot
(2)
Cone
8
(2)
Dome
W,M,T
(3)
PZ
PZ
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12
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4.5k
450,
4.5k
450,
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8
24x15
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24x15
x14
Wal.
-
NOTES
%
3Q
385.00
`Choice.
165.00
(1)
24x163
Wal.
Vinyl
16x9%
4k
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Vinyl
2314x14%
x12%
25%x1314
x153:
Wal.
31:x15% Wal.
8
x15%,
3114x1514
x15%,
3114x1514
8
8
Wal.
Wal.
195.00
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240.00
57
Each
Cloth,
blk.
Cloth,
blk.
Cloth,
blk.
Wal.
x31%
6x6x1214
20
48
Foam,
blk.
Foam,
blk.
Foam,
blk.
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blk.
Cloth,
blk.
Wal.
2314x14%
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5 colors
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5 colors
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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
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SENNHEISER
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15k
50-15
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Phone
15k
50-15
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Phone
40-20
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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
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RF
Metal
MKH-415
Club
MKH-435
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MKE-201
Omni.
MKE-401
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Satin
nickel
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chrome
Satin
chrome
Satin
nickel
Satin
nickel
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1.5k
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RF
cond.
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214.50
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72.50
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629.00
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529.00
7'/,x14
5
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495.00
7x%
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126.50
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147.50
-
-
NOTES
Adj. Freq. resp.
50.00
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DIN
2
330.00
tond.
'Double mike for bi
neural stereo.
-
HEADPHONES
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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
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Limited supplies at participating dealers.
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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
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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
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I
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CITATION
(CUSTOMER COMMENT CARDS ARE
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GAN 0000CV 0.Lww.W NY
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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.
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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
,
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DECEMBER, 1975
89
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-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.
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11
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Finally, you get the most generous warranty in
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Another innovation from Beyer Dynamic, the microphone people.
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Our gimmick
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Blackmore's Rainbow: Ritchie
more
Polydor PD 6049, stereo, $6.98.
This is what you might call an
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stylus.
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in his spare time made a solo single,
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Check No. 38 on Reader Service Card
Perhaps you've tried to track your
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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
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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
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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
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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
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Jon Tiven
it?
Sound:
92
B
Performance: 8+
AUDIO DECEMBER,
1975
Jazz & Blues
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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
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Taft Jordan and Bobby Stark. Hearing
their surging, exuberant playing, one
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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,
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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,
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Big bands have always possessed
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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
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This mixer-preamplifier gives much of the flexibility
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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
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And that's especially important when you've already
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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
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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
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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
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Gentle plush scrubbing pads get
deep into grooves ... remove for
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Only $19.95, suggested list price.
After years of research with all
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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.
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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.
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AUDIO
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MASS
or in person, find out the correct way. Also find out where to
MUSICAL
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WHILE YOU WERE LOOKING for out -of -print records, you
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2819
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I
Sales. Box 197, Wampsville, N.Y. 13163.
should've been looking for us.
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ULTIMATE DUPLICATION (10 up) from your program
"The Good Old Happy Sounds"
Banjo and Guitar. A moving and joyous sound. Twenty
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money order to:
Reilly Records
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RECORD COLLECTORS' CONTACT GUIDE. Dealers. magazines, societies, Handbooks and directories listed. $3.00.
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SERVICES
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$300-$1200 off
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DYNACO
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SCOTCH, CAPITOL. Blank cassettes, cartridges, reels. Discount prices. Lawson's. Box 510, Livermore, CA 94550
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RECORDING TAPE: Custom Loaded, 8 track, reel, cassette.
Prices on request. DICK WALEN, 4226 Robert St., Red Wing,
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Lowest Prices, Guranteed, New. S&S Audio P.O. Box 56039
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II.
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NEED ACRO 300 Ultra Linear Output transformer new or
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Apply in person or call 212 -SH. 8-8920.
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WANTED
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CANADIAN DEALER looking for American or British trade
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WANTED: McINTOSH 75 mono amplifier. Melvin Robinson,
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JBL, Thorens, Shure, BASF, TDK, Scotch, Watts, Maranta, etc.
Replies held confidential. Electronic Shoppers World, 278
Havelock, Toronto, M6H 3B9.
1
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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
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BS or equivalent. Experienced in de-
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igan 48184
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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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