Audio November 1959

Audio November 1959
('
NOVEMBER, 1962
SO¢
~,~" ............... ,
stylus is the world's
lowest dynamic mass,
880P.
Lower dynamic mass and higher compliance than any other cart- }
DYNAMIC MASS
ridge made . . . eliminates distortion and makes possible a lighter
3
less than .5xlO- gms { stylus, better frequency response, greater channel separation, and
the remarkable new standard for ...
COMPLIANCE
30 xl 0-6·c m / dyne
TRACKING FORCE-AS LOW AS 1/4 GRAM
At such low tracking force, the Empire 880P not only eliminates record
wear, but also eliminates distortion. To achieve the benefits of low force
tracking with the 880P cartridge, a tone arm capable of tracking at
such low levels must be used. We track every cartridge with the Empire
980 arm at less than a half gram before releasing it.
PERFORMANCE RANGE
6 to 30,000 cps
{
This is well beyond
the range of human
hearing
Greater separation than any other }
cartridge means greater enjoyment
of stereophonic sound
tl
empire 880 PAUdioPhile Net
S47.50
CHANNEL SEPARATION
more than 30 db
NOVEMBER,
1962 Vol. 46, No. 1.1
. Successor to
~,
Est. 1917
C. G. MCPROUD • Publisher
DAVID SASLAW
•
Editor
JANET M. DURGIN
Production Manager
A . SCHOBER
Business Manager
R epresentatives
Contributing Editors
Bi! I Pn ttis & Associates,
EDWARD TATNALL CANBY
HENRY
SANFORD
L.
1,"'/61 W e8t 'Pon 7ly Ave ..,
Lincolnwood 1,6, Ill .
JOSEPH GIOVANELU
Jam es C. Galloway,
CAHN
Advertising Director
6535 'Wilshi'r e B l vd. ,
HAROLD LAWRENCE
Los Angeles 1,8, Calif.
'Vnrt' PB Birkenh ead, Inc. ,
No. 2 .;, 2-oho",e, Sh-iba IIallw,
1na,t."1u.-c ho.,
.IH·n nto-lv·lf, ) 'l'okyo ., Japam,
EDGAR E. NEWMAN
Circulation Director
Vertical Tracking Angle- A Source
of 1M Distortion
Let's Talk About Tape Synchronizat ion
A High-Quality Transistorized Stereo
Preamplifier- Part One
A TransIstorized 200-Watt
Stereo Amplifier
A Headphone Control Center
For Monaural, D iotic, and
Binaural Listening
;
1
Ask your
High Fidelity
Dealer
which components
rate highest!
CHARLES
A.
ROBERTSON
CHESTER SANTON
AUDIO Articles
21
25
E. R. Madsen
Hal H al'gargle
30
Erhal'd Aschinger
40
Richard S. Burtuen
55
Robert J. Larson and
John M . Eargle
AUDIO Reviews
Light Listening
Record Revue
Jazz and All That
8
70
76
Chester Santon
Edward T atnall Canby
Charles A. Robertson
AUDlO~ Profiles
Heathkit Stereo Tape Recorder
Shure-SME Tonearm
Shure Stereo Cartridge
62
64
66
Model AD-22
Model 3009 Series 2
Model M33-5
AUDIO in General
Audioclinic
This Month's Cover
Letters
Audio ETC
Editor's Review
Tape Guide
About Music
New Products
New Literature
Industry Notes
Advertising Index
itj """ ' '"'
2
4
6
10
18
28
68
Joseph Giovanelli
Edward T atnaIl Canby
Herman Burstein
Harold Lawrence
82
85
92
94
Your high fidelity dealer will gladly ex·
plain and demonstrate all of the technical
features ... the advanced circuit design
.. . the proved reliability that make
Sherwood components our best buy for
your listening dollar .
today and for
years to come.
A Sherwood bonus is the beautiful
styling of each component . .. styling
that is a complirAent to any decor.
Also ask your dealer about the new
Sherwood S·2100 FM Stereo Multiplex/ AM
Tuner with Stereo Indicator Light and
pace'setting performance. Terrific fea·
tures . . . terrific buy at $199.50.
-MEM8ER·
""'nulf o.
$_
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'INC '
c,-t,'"
"","re'
reo••• ~ ......~­
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zincs, Inc., Henry A. Schober, President; C. G. MeProud. Secretary. Executive
and Editorial Offices. 204 Front St., Mineola, N. Y. SubscrI ption rates-U. S.•
Possessions, Canada. and Mexico, $4.00 for one year, $7.00 fo r two years; all
other countries $5.00 per year. Single caples 50¢. Printed In U.S.A. at 10
McGovern Ave., Lancaster, Pa. All rIghts reserved. Entire contents copyrighted
1962 by Radio Magazines, Inc. Second Class postage paid at Lancaster. Pa.
RADIO MAGAZINES, INC., P. O. Box 629, MINEOLA, N. Y.
Postmaster: Send Fonn 3579 to AUDIO, P.O. Box 629, Mineola, N. Y.
AUDIO
•
NOVEMBER, 1962
HIGH FIDELITY
Sherwood Electronic Laborat<nies, Inc.
Dept. A-ll, 4300 North California Avenue
Chicago 18, Illinois
AUDIO CLINIC
Send questions to:
Joseph Giovanelli
3420 Newkirk Ave.
Brooklyn 3, N. Y.
Include stamped, self-addressed
envelope.
FM Receiver Tuning
New Stereotron Antenna and 2 Nuvistor FM
amplifier will positively improve your FM
set performance; pulls in far -away stations!
Now an FM antenna has been designed by
Winegard that will deliver unexcelled FM
and FM stereo listening whether you live
close to FM stations or 200 miles away. The
new Stereotron is so powerful, so efficient
that we llctually guarantee better performance from your FM, guarantee that you will
receive 85% of all FM stations in a 200
mile radius.
The Stereotron Antenna (model SF-S)
with Stereotron 2 nuvistor amplifier (model
AP-320) is the only antenna-amplifier combination that can be used anywhere. Nuvistor
amplifier takes up to 200,000 micro-volts of
signal without overloading-yet responds to
signals of only I micro-volt. The Stereotron
with nuvistor amplifier has minimum gain of
26 DB over a folded dipole and flat frequency response of ± 1,4 DB from 88 to 108 mc.
Antenna is GOLD ANODIZED, amplifier
completely weather-sealed. Available for
300 ohm or 75 ohm coax.
SF-8 Stereotron Antenna $23.65
AP-320 Stereotron Amplifier $39.95-can be
used with any FM antenna.
Write for information and spec. sheets
t-oday on the Stereotron and other Winegard
FM and TV antennas and accessories. Get
FREE Station Log and FM map of U.S.write today.
World's Most Complete Line 0/ FM and TV
antennas, FM-TV Couplers and Amplifiers
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3008-11 Kirkwood Blvd .• Burlington, Iowa
2
Q. Whenever I tune in a local station
on my FM tuner, I find three peaks of
tuning. As I go from left to right and approach a station, the station seems to come
into tune (b ut not completely) then out
of tune, then into tune again (this time almost completely) then out of tune, then
again in tune (but not sharply). On distant
stations there are two peakS, neither in
tune.
I have tr'ied to align the tuner by following alignment instructions. By so doing, I have succeeded only in sharp~in?
up the center pe,ak a little more, but it ~s
still not as sharp as I think it should be.
In some cases, the left and the center
peaks are equally sharp. This co"!'ditio?"
prevails whether the multiplex sWltch ts
on or off.
Can you tell me the cause of this condition? What can I do to remedy it? John J.
Gordon, Levittown, Pennsylvania.
A. The situation you describe is normal
operation for most FM tuners. The proper
point for correct tuning is the center peak.
The reason that the peaks act differently
with different signal strengths is that the
selectivity characteristic of the Lf. system
changes with signal strength. As the signal grows weaker, the selectivity increases
with the result that the signal is no longer
audible when the outer peaks are reached.
Further, the alignment of the detector
shifts strength, moving the peak somewhat
off the center position of the bandpass of
the Lf. strip.
The center peak will broaden out as the
signal increases in strength. The broader
this peak becomes the better, for at its
broadest the tuner is in full quieting and
the i.f.'s are likely not to clip any of
the extremes of modulation.
Projectors and Public Address Systems
Q. I have encountered a problem for
which I have been unable to work out a
solution. The technical details are as follows: A motion picture projector with
built in sound system is to be converted
for use with an existing sound system
in an auditorium. The projector incorporates a st,andard 10-watt amplifier using
push-pull 6V6's and outputs for 8- and
16-ohm speakers. The sound system has four
inputs, two high impedance and two l.ow
impedance, the low impedance belng
50/150/250/600 ohms. Numerous proced1t1'es have been tried to match the projector's output to the amplifier with little success. This has included various resistance
pads to match the 16-ohm output to the
50-ohm inp1tt transformer on the sound
system amplifier. A tr,a nsformer was tried
in order to accomplish the same match.
Both of these procedures produced distorted sound and appeared to drivll the
sound system too hard. I have thought
of replacing the output transformer in the
projector with a unit having a SOO-ohm
secondary. However, no commercial unit
is available which will fit the space IIllowed.
It appears that the push-pull stage is
driving the sound system too hard. It
will probably be necessary to go ahead
of the push-pull stage and use a single
plate-to-line transformer. Daniel K. Hiskey
Yorba L ind,a, California.
A. You are correct in thinking that the
sound system is being driven too hard.
An attenuator of some kind is needed.
First of all, why use the 50-ohm input'
Use instead one of the high-impedance
inputs. Presumably these ar~ u~ed for
feeding phonographs and the like mto the
system. They possess less gain and pose
less of a problem. Do not try to match
impedance. Terminate the projector with
a resistor of either 8 or 16 ohms as may
be convenient. Then connect this input
directly to the high-impedance input. Adjust the volume controls of both the
projector and the sound system for best
signal-to-noise r atio.
I do not reco=end that you take output from a preceding stage in the projector
unless you are sure that this procedure
will not interfere with feedback or equal·
ization.
It it happens that the high-impedance
inputs are designed with low-level circuits
rather than the high-level sources assumed
here, the above procedure must be altered.
A potentiometer whose value is equal to
either 16 or 8 ohms can be placed across
the terminals of the projector, with the
signal taken from the arm of the potentiometer and fed to the appropriate point in
the p;ojector. If the action of this potentiometer is too coarse, terminate the
projector's output with a 16- or 8-ohm
resistor. Connect a lOO-ohm resistor to
the "hot" output terminal. The other end
of this resistor should be connected to one
end of a 10-ohm potentiometer whose other
end is grounded. Signal is taken from the
arm of this potentiometer and ground
and is then fed to the appropriate input
terminal on the projector, preferably the
AUDIO
•
NOVEMBER, 1962
your investment
in a Garrard
Automatic Turntable
pays off
Chances are that sooner or later you will spend
more on your records than you do on any record
player. More, it may be, than the cost of your
entire music system. Your listening enjoyment
is dependent upon records and the unit that
reproduces them. This is exactly why more
GARRARD Type A's, for example, have been
sold-and are being sold-than any other high
fidelity record playing equipment, without regard to cost. Just consider this ...
Most people today want to use one of the ultra
sensitive cartridges developed originally for
separately-sold tone arms because of high compliance. Garrard has integrated precisely such
an arm in the Type A Automatic Turntabledynamically-balanced, counterweight adjusted,
designed and built with the same precision, the
same balance, the same freedom from friction,
the same playback characteristics and low resonance. This arm, operating in conjunction with
the Type A's heavy, full-size, non-magnetic turntable - a laboratory-balanced, double-shielded
motor; and (when you want it)the gentlest autom atic record-handling mechanism ever designed;
rewards you with the full measure of the magnificent reproduction you expect from the best
recordings.
Garrard's Type A Automatic Turntable is
proudly owned by a growing legion of highly
critical people who, originally amazed at the
$79.50 price, have come 't~ realize this completely integrated precision instrument could have
been developed only by the Chr'r ard Laboratories.
For illustrated literature, write Dept. GS-12,
Garrard Sales Corp., Port Washington, N . Y.
.and Canada to Garrard Engineering and Mf g. Co., Swindon. Wil ts ., England
The sweep and magnificence of a full
orchestra . . . the intimacy of a lovely
voice. The pure sound of Grommes faithfully reproduces the mood and expression
-with the elusive quality of " presence"
You are there!
Model 24PG 24 watt stereo amplifier .
.$ 89.95
Model 36PG 40 watt stereo ampl ifier . . . .. $129.95
Model 70PG 70 watt stereo amplifier ..... $199.95
Write GROMMES
Division of Precision Electronics, Inc.,
9101 King St., Franklin Park, III.
C;;II. 6-IH H1. e-L
sets the
scene •.•
high-impeda nce input. This latter connection is preferable because the impedance
mismatch will result in a fur ther attenuation of the signal.
Impedance mismatch can be used in instances such as this because ma.ximum
power transfer is not desired. The impedance which must be matched properly
is the impedance at the output of the
projector. No other matching need be considered. In fact, we would not be concerned
with matching th e impedance of the output
circuit of the projector were it not for the
fact that it is always desirable to have the
outp ut transformer properly loa ded so that
the feedback loop will operate properly and
t here will be no chance of accide ntal damage to the output transform er ca used by
excessivel.r high voltages in t he primary
ci rcuit.
Refrigerator Interference
Q. Every time 1I1y ?'ef?'ige'l'ato!' starts I
heal' lO1id "pops" in my speakers. The
" pops" are ?nost annoying and pronounced
when I 1tSe ?ny FM tuner. I have t?'ied
b?'idging the power pl1tg with a 0.05 [J.f 600
v.cl.c. oapaoito?' but it only ?nade the "pops"
loude?·. B erna?'Cl Mmtg ham, BTonx, New
Yo?·k .
A . I may not be able to be of much
help because of th e nature of some house
wiring and th e nature of r efriger ator actiO ll. Duri11g certain parts of th e r efrigerator's cycle of operation, the unit will
draw considerable current from the line.
This will cause the line voltage to drop
markedly wh en the house wiring is old or
THIS MONTH'S COVER
This month we have. an opportunity to
glimpse into the home of Jerome Brent,
D.D.S., of Forest Hills, N. Y . In the words
of Dr. Brent, "The idea in building this
installation was to have a good-looking
cabinet which wonld be unobtrusive when
the doors were closed, yet contain all the
components I thought necessa ry." The cabinet was built by Weathervane but the i nterior work and the installation of components were carefully executed by the owner.
The entire decor of the room, of which we
see only a small part, was planned by
Arthur Getter, AID. Photographs by
Pan-ad Associates.
The equipment consists of the following:
Weathers ML1 turntable, Grado L aboratory tonearm, Shure M3D cartridge, Viking
Series 75 tape deck (4-track play back
head), 2 Dynakit PAM-1 preamps with
DSC-1 stereo control, 2 Dynakit Mark III
50-watt power amps, H. H . Scott LT-110
tuner, Concertone 505-4 tape machine. The
speakers are 'fannoy 15-in. monitors in custom·built bass r eflex enclosures. '1'he Dynakits and Scott t uner were built from kits.
In addition to the components th e following is built in: A matrix of pilot lights to
indicate mode, a stereo output meter, a
jack for earphones, a tape storage drawer,
microphon e jacks, and convenience outlets.
LAST MONTH'S COVER
Here is t he end of the story abou t last
month's cover. Since the missing pa rt starts
in the middle of a word we will back up a
little to page 60 in the October issue as
foll ows:
not sufficielltly hea,y to allow the proper
operation of the various appliances now
available. This sudden change in line voltage will manifest itself in clicks or "pops"
as a r esult of the fact that the voltage
on all circuits in the high fidelity system
will be subject to a momentary change.
If the problem is one of eliminating
"simple" transient clicks from the line,
you can only do that if you can gain access to the wiring of the thermostat of th e
refrigerator and bridge its contacts with
a series network consisting of a 0.02 f,lf
capacitor and a 200-ohm resistor.
You may be able to gain some relief f rom
this condition by using a line-interference
fliter between your equipment and t he a.c.
supply line. Be certain that yo u have
bought a good filter . Some filters have
been made with nothing inside them but
plaster-of-Paris: This kind of filter will
filter nothing at all.
You indica ted that these transie nt
clicks are most pronounced when your tuner
is in use, therefore it is possible that some
of the pickup is coming from the an tellll a
circuit of the tuner rather than from
coupling into the equipment vi a the power
line. It seems logical, therefore, that the
line cord of the refrigerator, and the
power line itself, is radiating this energy.
Therefore, some further relief may be afforde(1 by bypassin g each side of the r efrigerator's line to a good ground, connecting the bypass capacitors either inside
t he r efrigerator or at the point where the
line cord enters the r efrigerator. 0.1 j.tf
capacitors, 600 v d.c., should be used as pos1£
sible sta r t ing values.
Additional phone lines hidden under th e
carpeting and terminating at a receptacle
behind the sofa permit use of the phones
at the room's optimum listening point, without the need for visible wiring. By utilizing
either this input or a four-conductor extension line from the panel, a listener may
wear the headphones a t any point in the
room. Because the panel hangs from t he
shelf supporting the preamplifier, Marantz
switches and knobs were used for visual
symmetry.
The owner had planned originally for
all equipment, less the speaker systems, to
be housed in a single cabinet. But it was
realized that a cabinet with sufficient capacity to honse the equipment and a sizeable record collection ... and provide space
for f uture accommodation of a tape deck
. . . would appear too massive. A wallmounted unit with the necessary record
storage and equipment capacity seemed to
be the answer.
The unit decided upon was designed by
Contemporary Furniture D esign, Inc., of
New York. Of oiled walnut, it combin es
space for all of Mr. Jacolow's present
equipment plus a tape deck with cabinetry
for storage of up to 500 records, a bar, an
antique glass-doOl'ed cabinet, fitted with a
slotted top and bottom for heat dispersion,
in which the amplifier has been housed, a
three-drawer chest for silver and table
linen stor age and knick-knack shelves. By
anchoring the unit's four uprights directly
into beams, and because the cabinets suspend from horizontal pins passing through
the uprights so that weight is literally
forced against the wall rather than down,
weight is no problem.
The r esult of all this effort is a stereo
system full y capable of satisfying the most
discriminating music-lover and audiofan.
And it is beautiful, too.
]£
AUDIO
•
NOVEMBER, 1962
.
The most advanced achievement in recorder engineering to date, the superb new
remote-controlled professional Sterecorder 777 series features the excl~sive and patented
Sony Electro Bi-Lateral 2 & 4 track playback H ead, a revolutionary innovation that
permits the playback of 2 track and 4 track stereophonic or monophonic tape without
track width com promise - through the same head!
Included in an array of outstanding features are individual erase/record/playback
heads, professional 3/1 VU meters, automatic shut-off, automatic tape lifters, an allsolenoid, feather-touch operated mechanism, electrical speed change, monitoring of
either source or tape, sound on sound facilities, and an all-transistorized military plug-in
type circuitry for simple maintenance. The three motors consist of one hysteresis
synchronous drive motor and two hi-torque spooling motors.
Unquestionably the finest professional value on the market today, the 777 is available in two models, the S-2 (records 2 track stereo) and the S-4 (records 4 track stereo).
Both models can reproduce 2 and 4 track tapes.* And, the Sterecorder 777 models will
integrate into any existing component system. $595 complete with portable case and
remote control unit.
*Through the exclusive Sony Electro Bi-Lateral 2 and 4 track Playback head.
All Sony Sterecorders
Bre Multiplex ready!
SUPERSCOPE
The Tapeway to Stereo
Sony has also de veloped a complete portable all-transistorized 20 watt speaker!
amplifier combination, featuring separate
vo lume, treble and bass controls, mounted in
a carrying case that matches the Sterecorder
777. $175 each.
Also available is the MX-777, a six channel
dll-transistorize d stereo!mo nophonic mixer
that contains six matching transformers for
balanced microphone inputs and recorder
outputs, individual le vel controls and channel
selector switches, Cannon XL type receptacles,
a switch to permit bridging of center staging
solo mike. $175 complete with matching carrying case.
The first! complete! portable! all-transistorized! high fidelity! professional recording &
playback system: $1120 complete.
Sold only at Superscope franchised dealers.
The better stores everywhere.
For additional literature and name of
nearest franchised dealer write Superscope,
Inc., Dept. 7, Sun Valley, California.
SPACE
BREAKTHROUGH I
How the New Fainhild Integra ISeries ~
Puts 100 Complex Audio Control
Components in a Space 28" x 30 ".
20
20
20
20
20
100
Compressors
Pre-Amplifiers
Equalizers
Noiseless Attenuators
Noise Reduction
Systems
Audio Control
Components in a
space 28" x 30 "
The new F air child I ntegr a/ Series, a group of m iniature
au di o control compon ents (1 %" n arrow) is t h e first
a nd only space br eakth rough in r ecor ding, broadcasting
and speech r einforcement systems coupled with h igher
qua li ty perform a n ce. Th e Fai r chil d In t egra/ Series,
b r ou g ht a bout thr ough t h e use of t h e m ost rece n t
a dvan ces in solid st at e des ign, allows you to build t he
most complex console entirely within t he r each of your
fingertips. Now you can have a n individu al no-dist ortion
compressor , a n a utoma t ic attenuat or (AUTO-TE N-X-), a
50 db high out put, low distor tion t r ans istorized prea mpli fie r , a new a ttenuat or (LUMITE N*) guaranteed
no iseless, a nd a fl exible p r ogram equalizer for every
ch annel. All Fair ch ild Integra/ Series components complement each other yet each component can be bought
separ ately and work ed as an independent' un it wit h all
ex is tin g co n ve nti on a l eq u ip m ent. Inc lu ded in t h e
Fairch ild Int egra/ Series:
• 'l'rnde
Mark
Model 663 - A no distortion compressor
Model 661 - An automatic attenuator (AUTO-TEN)
Model 662 - A 50 db high output, low distorfion
transistorized preamplifier
Model 668 - A new type attenuator-the LUMITEN,
guaranteed noiseless
Model 664 - A flexible program equalizer
Only w ith the FAIRCHILD INTEGRA/SERIES
can you make a sound investment in the futur e.
Send for doto on the compl ete FAIRCHILD INTEGRA / SERIES SYSTEM.
FAIRCHILD
LETTERS
Condenser Microphone Match ing
SIR:
We take issue with the article "A condenser microphone
mixer" ill t he October, 1962, issue of AUDIO. As the exclusive
importers and r epresent atives for the Neumann Company of
West Berlin, Germany, we h ave spent the past four years in an
earnest campaign to acquaint those Neumann microphone users
who bought their units before we became the importer, with
the proper netwol'k which has to be installed in all of our microphones to permit their operation with the standard a mplifier
inputs used in this country. This information is contained in our
engineering bulletin No. 6032, which is available to anyone who
requests it .
In order to understand properly the b asic difference between
the European (German, French, Austrian, and other parts of
Western Europe) a.nd the American standards in the professional field, it is necessary to explain that the U. S. follows a
"ma t ching" sys tem of impedances in which the input and output
of every amplifier provides for a specific impedance to which
jt must be connected to perform as specified. _Terminating with
other t han r ated impedance produces frequency discrimination .
'l'his is largely because the input and output transform ers used
take advantage of certain winding capacitances at their upper
frequencies to flatten out the over-all response. This effect ,vill
work properly only if the p articular tran sformer's impedance
requirements are met.
In Europe, on the other hand, we find a voltage standard; i.e.
oue in which there is no significant power transferr ed from one
output to the next input . This is done by virtue of something
which we in this' country call "bridging." We do this when we
want to connect some input such as a monitor amplifier across
a 600-ohm line without deteriorating the dbm level in th at line.
This can only be done, however, if the 600-ohm line is actually
terminated with a 600-ohm resist or. Here is wher e t he Eu r opean
method differs. T hey can go from one impedance (usually about
40 ohms) right to a higher impedance (usually 1000 ohms or
more) without connecting a 40-ohm r esistor acr oss the output
of the first amplifier.
You will find that microphone inputs on German consoles are
rated at about 1200 ohms and further state that you may connect any impedance to them which is % of that impedance
(240 ohms ) or l ess. Likewise, all condenser microphones (they
contain amplifiers and therefore come under this heading ) are
switch able to either 50 or 200 ohms and are indicated to be
operated into no l ess than 5 times their impedance, or 250 ohms
for the former and 1000 ohms for the l",tter adj ustment or more.
The transformers and circuitry surrounding them ar e so designed that an impedace match is not only not needed, but
not wanted.
Now let us l ook at t he problem of conuecting a Neumann
U-47 microphone, or any Neumann microphone for that matter,
to an input of 250 ohms on an American console. On the one
hand the microphone wants to see a minimwrn of 250 ohms
(when set for 50 ohms itself) while t he input of the preamp
must see exactly 250 ohms. To accomplish this we use two series
resistol'S between the two. These ar e already installed on any
Neumann microphone sold in the last four years in this co untry.
They do not constitute a p adl The Models U-67, U-47, and U-48
are also considerably more sensitive, as Mr. Dilley points out,
an d for this reason these units combine a loss pad with the
above mentioned network. We are in wholehearted agreement
with Mr. Dilley that it is r egrettable that thi s avail able gain
must be wasted at this point and we welcome in principle the
design of a mixer which provides for inputs of this magnitude
without over loading. It must be stressed, however, that this
is only the case with these three micr ophone moclels an d ·not
with our other condenser units such as the SM-2, KM-54a,
KM-56, M-49b, M-50b, M-269. All of these provide a level only
some 8-db higher than domestic dynamic 01' ribbon units which
a normal console input should be able to handle.
I trust that this gener al explan ation has served partia lly to
clarify an age-old problem with condenser microphones. We are
delighted with Mr . Dilley's idea of such a mixer and we are
sure that he will so change his input cir cuits as to conform to
these conditions. Failure to do so will produce premature over load of the microphone amplifi er if the microphone's 200-ohm
outpu t is connected to the console's 250-ohm input, an d a highf r equency peak if the input of the p reamp is under-terminated
with the microphone set for 50 ohms.
S TEPHEN F. TEM MER
Gotham Audio Corp.,
2 West 46th St.
New York 36, N. Y.
RECORD ING EQUIPMENT CORP., 10-40 45TH AVE., LONG ISLAND CITY, N. Y.
6
(Cont imLed on page 79)
AUDIO
•
NOVEMBER, 1962
YOU SUPPLY THE FREQUENCIES ... KODAK TAPE SUPPLIES THE RESPONSE
Listen! The dramatic crescendos and crystal·
clear highs are the result of the fine, tight
magnetic domains that are characteristic of
the new KODAK Sound Recording Tape . But
frequency response with a minimum distor·
tion is just a part of the story. Kodak tape has
a coating so uniform that it never varies more
than 14·millionths of an inch.
New KODAK Sound Recording Tape is man·
ufactured to the same super·critical stand·
ards as is Kodak film. Standards that have
never been exceeded in any coating process.
The result is remarkable uniformity from roll
to roll, and unusually high sensitivity. Kodak
tape is lubricated on both sides to prolong
its life as well as that of the recorder head.
KODAK Sound Recording Tape is available
in all standard lengths. And there is a built·in
splicer on the reel. Try this fine new sound
recording tape today.
@E a s lnHlIl 1';:()(l nk Compa n y MCl\H.X I
EASTMAN KODAK COMPANY, ROCHESTER 4, N. Y.
AUDIO
•
NOVEMBER, 1962
7
Sounds of V ictory
London Tape LPM 70052
This month's occasion for rejoicing a mong
tape fan s is the news t hat London Records
has issued a band recording t hat surpasses
one of its most famous sou nd spec ial ties of
the past season. Slight ly more than a year
ago, the tape, called "Pass in Rev iew" kicked
off t he Phase 4 series on this la bel with a
resounding t hump. That r ecreation of a military parade swaggering past from on e
speaker to another struck this "observe r" as
a particu la rly successf ul example of sound
in motion whose audio qua li ty ra ised a tanta-
li zi:~g qu e.s tion ..'l'h?, record and tape version
of Pass IU Rev Iew revealed in no un ce rtain
terms that London was now Cal)able of turning out a terrific product even when go in g
t hrough the maze of electronic gea r called for
in the multi-track Phase 4 process. Th e
ta n talizing question: b ow would a brand n ew
sink far below the mlDImum poiu t decreed
for LPM 70044. Withont limi ting circnitry to
bat down the peaks, the highs on t h e later
tape are sweeter and cleaner. No matter how
impreSSively low in distortion t h e most r ecent limi ters may be, fo ur-track tapes man·
age to sound better without them. Even the
hobbyist who h as confined him self to djsc
playback is famili a r with the fact that his
friends Wl1 0 are tape fans have been getting
better r esu lts with t heir own four-t r ack
tapes recorded on the premises than they
have with th e general run of fo ur-track commer cial r eleases. Thi s la test Manotovani r eel
s hon ld h elp to convince both camps that
store·bought tapes a re now getting mighty
close to the recorded·at-home product.
Lester Lanin and his Orchestra
Epic BN 628
T il is r econl provid es my fir s t oppo r tun ity
painstaking recording 0( a band so und u nder
to check til e quality of COlumbia's "ElecL ondon conditions of optimum s im pli city?
tronically
Re-Chan neled For Stereo" sonnd
\Ve have our answer in this r elease. If you
in an album devoted to something other t han
don't get around to hea ring It by some means
Broadway sh ows. Not too long ago, t h e
or other, yo u' re miSSing wh at to me is th e
"South PaCific" and "Kismet" orig inal cast
first convi ncing demonstration that fo ura
lbums were reissued on Epic's parent label
track tape can now gen uinely co mpete wi t h
and
wer e g reeted with conSiderable enthustereo disc in terms of frequency response.
s ias m in t hi s co rn el' beca use they were t he
P ick an", tape. ~ ss u ed before th is one featuring
first good examples of pseudo s tereo !',e
a f ull-sIze m IlI tary band a nd unroll it past
co me ac ross. The fi rst probl em facing any
a ca refully a lign ed playbact{ head. Then folfirm
th at engages in th is so r t of rescue operlow it with this Sounds of Victory r eel. Only
H tion is t be condi t ion of tbe mono master
then will you reali ze t h at LPM 70052 h as
tape. Although t h is al bum is th e earliest
bona fide , honest-to-goodness aliv e a nd kickLan in item in t he catalog (it was a llegedly
ing highs t hat a re n ot th e produ ct of treble
I'eco rded in the course of the Monte Carlo
p reemph asis. UST can take a bit more cred it
Ball in New Yo rk City in the spring of 1956
for t hi s feat t h un London itself but both are
to be congratu lated on the sco pe of t heir . wb ~ n Prin ce Raini er and Grace Kelly made
accom plish men t. The Band of the Gr enadie!f >. t helr first publi C appearan ce after announcGu.ards is the lucky gro u p that's gOing t·o· io;;U¥ th eir engagement), the maste r tape cert~ lIll y hus no trouble el eli vering the ran ge
~ n JO.\' t he close attention of tape's boos ters
of sO llnd to which today's ste reo cu tters have
In t he months to come. Among t he milita ry
become acclls t omed. Sin ce bot h t he Columbia
ma r ches and com bat tunes featu red in this
li nd Epic la bels a re processed in esse ntially
release, the Guadalcanal Ma.' ·ch from Richard
the
same pla n t, t he techn icians ha ve electecl
Rodge rs ' "Victory at Sea" will probably enjoy
to follow a s im ple clevice in identify ing each
greates t pop ula ri ty as a demo nstration o'f
label's electron icany re-chanl1 eled ster eo .
what this tape ca n delh·er .
Thi s Epic r elease carries the difference Signal
(L-R) in t he ri gh t channel. Co mpa rison of
t he two chall nels of t his recording p rov ides
Mantovani: Song Hits from Theatreland
a . pa rticularly effective a nd revealin g glimpse
and Carn ival
London Tape LPK 70054
of the work ings of t h e Colum bia r e-chann elin g process and olter s a good explanation of
, <?nite apar t f roIl; t h e ir oth er Yirtu es, the
th e r es ults t hey obtain. Naturall y, ste reo
Tw~~pak r eels rollmg out of the four-track
depth here does not impress to t he extent of
fac II.ltIeS of United Stereo T apes are now
tile real th ing but separation is fu ll y np to
se rvIng .a n unforeseen purpose. As some of
snuff. Th e clance r eper to ry played i, ere by
t he preVlously released tape a lbums al e bein "
Lester L an in is t he hard-core SOCiety stuff
teamed up to form Twinpak pairings eq niva~
that established hi s reputation on r ecords
l en~ to t.wo norma l a lb um s, a f resh oppora nd sparked a r eY iva l or interest in this type
tun l ~y an ses to gauge a dvan ces in the UST
of
dance music.
dupbcatInI!' p rocess. There isn 't a t ape fan
an~whe re ID need of r eminder tha t t he duplicat Ing process h as long been the bottlen eck
Showboa t
ID t he production of commercial tapes The
Columbia OS 2220
"A" s ide of th is Twinpak, "Song Hits' from
Theatreland," firs t appea red on a Mantovani
. It was slow in appearing but here at last
~ape as an Individual release (Lon don L PM
IS a stereo r eco rding of th e fam ili a r J erome
(0044 ). Gomg from t he earlier r elea se to
Kern classic t h a t pacl,s as much pu nch in its
~ hi S 'I."~i n pa l' reel is mo re tha n moderately
sound as do the songs themsel ves. Not that
IDstructIve. The first thing I noticed wh en
the wooels have been f ull of ster eo version s
makmg the comparison was t hat t he newer
of this famous mu Sical of life along the Mistape ha s .been gi ve n a considerably r ed uced
sissippi. Until this r elease of "Showboat"
over-all 'Ignn l le"el. At t he same ti me the
cn ll~e along, the on ly stereo record jng on a
dynamic range of t he mo re r ecen t reei has
maJor lab~1 h as been t he RCA Victo l' prodn cbeen a llowed to follow mo re closely t he n attlon starrlllg Ann Jeffreys and Howard K eel.
u ral ri.se a nd fa ll of t h e orch estra's volume.
That r elease offered l ess mu sical impa ct t h an
There I S far less evidence of the peak limiting
sever al of the old mono sets. You do n' t have
that kept most of t he ea rlie r tape in t h e
to look far to find an expla nation for th.is
upper ha lf of its vol um e range. Tape noise
state of affairs. Any record pr oducer, if
has been lessened enough on London LPK
pressed for a reason, will h asten to admit
700::;4 so t hat t he mu sic level is permitted to
that "Showboat" Isn 't t he easiest of musical s
8
to cast. The public, even at this late date,
tends to assoc ia te some of t he roles with
illu strious theatrical sta rs of the past. I n
view of t h e fame that later came to most of
t be members of t be origin al cast , It's a bit
hard to believe that F loren z Ziegfeld firs t
brought the show to New York in 1927 with
a cast that boasted no establish ed stars In
the lin eup. The status of Charles Wlnninger
a nd Helen Morgan underwent quite a change
after their a ppearance in "Showboat." When
Ziegfeld revived t he s bow in 1930, Dennis
King a nd Paul Robeson were t be only r eplacements in tb e original cast. The r ecord
industry had its fir st co nvenient opportunity
to r eco rd a Broadway "Showboat" cast when
the musical had Its second major revival in
1946. Columbia's 78·rpm album starring Jan
Clayton, Carol Bruce, Cha rl es Fredericks, a nd
K enn eth Spenser was co ns id ered important
enou gh at t he time to merit in clusion among
t he fi r,t few ba tches of r ecordings to be
chosen for transfer to Long P lay when the
n ew speed cnme al ong. For many years, the
1946 r evival cast on Columbia LP 4058 was
pretty much t he standard reference pOint
among show fans searching for a "Showboat"
score on r ecor ds. Although out-distanced In
sound qu ali ty by a ll t h e "Showboat" recordings of mor e recent year s, the 1946 disc has
been most valu a ble in preser ving a link with
t he past. Th e latest Columbia r elease starring
John Raitt, Barbara Cook. An ita Darlan , and
William Warfield models itself for t he most
pa r t on t h e traditional approach of t he older
release. To mold the entire production, Colnmbia h as been fo rtunate in acquiring tbe
services of veteran conductor Franz Allers.
His many year s at the h elm of the pit orchest ras of t he great Lerner and Loewe Shows
("Paint Your Wagon," "My Fair Lady," and
"Camelot") give him a h ead sta r t In a sco re
s uch as thi s. The big numbers i n the show,
Ma k e lJ eUeve, Y ou Are Love, a nd Why Do J
Love Your, are in fin e ha nds d nring the
smooth du ets of Barbara Cook and J ohn
Rait t. Th e Merrill Staton Choir rounds ou t
tbe cast of singer s and t he whole production
definitel y benefits f rom the advances made in
Columbia's new Stereo "360 Sound."
Music of Leroy Anderson
RCA Victor LSC 2638
Th e experim ents in Boston's Symphony
Hall con tinue a pace. Recent releases by th e
Boston Pops r eveal that RCA is st ill trying
to arrive at a miking a rra ngement that i t
hopes will offer a more competitive sound in
todllY's volatile stereo market. The pressure
being exe rted by some of the strea mlin ed
newer Jabels is a factor n ot easy to dis mi ss
at any large company today . It will h a rdly
surpri se a nyon e who h as fo llowed the for t un es of the r ecord indu stry for the pa st
decade and a h a lf that t h e mass market remains a ba sic consideration in t he pOlicies of
the major ontfits. The Boston Pops OrChest ra , long one of the top sell ers in the Victor
catalog, is a pretty good barometer of t he
t rend toward mass-market soun d now nnderway at that label. Ce l·tainly the la test Pops
reco rdin g makes less demand on stereo playback equi pment t han former di scs Issu ed by
Arthur l~ i e dle r. The mikes appear to be only
a few yards above the in struments. At this
rate it should be possible to get "Hi F I"
presence on eq uipment t hat i s l ess than middlin ~. A . ignifica n t increase in signal level
on t he reco rd acco mpanies the decision to
1ll0\'e t he microphones toward the h ea r t of
the orchestra. This u ew med icine unfortunately h as a s ide effect t hat is fa r from favo ra ble in terms of tbe room ambience that
s hou ld be a par t of any weli-made stereo record. The first two bands of t his album de\'oted to L eroy Anderson favo rites could quite
eas il y be confused with a typ ical mono Pops
d isc played through both cbannel s of a stereo
set up. Wi thont t he us ual hall sound always
associated with t h e Bosto n Pops before these
expe riments got nncl e rwa~r , t he ear takes
so me t ime to get u sed to t he new sound. A
fllI·ther com plication t hat tends to give the
ti l' ,t two bands (FiddLe-Faddle a nd B~ue
'l'un go) a mono t in ge Is the fac t that t h e
strings no longe l' st retcb aC ross the en t ire
di stance that se parates the loudspeak ers. Instea d, t be s trings appear to be ti ed up in a
knot of sou nd at the cen tel' of the listening
area. It's not until tbe lis tener r each es Band
(Continued on page 58)
AUDIO
•
NOVEMBER, 1962
How to install
(1) an FM stereo tuner with Multiplex,
(2) an AM tuner with variable bandwidth,
(3) a stereo master control center, and
(4) a 65-watt stereo power amplifier,
all in 20 seconds:
Take a Fisher 800-B. Connect your speaker wires to it. Plug it in.
Yes. That's all it takes to get the Fisher 800-8
ready to play. This famous integrated stereo
receiver incorporates four of the world's finest stereo components - all on one superb
chassis. The entire unit takes up only 171f2
inches of shelf space and, most remarkable
of all, it is only 13 1/2 inches deep.
To include all the 'electronics' of a topperformance stereo system in a single unit
is no small engineering feat. High quality
combined with single-chassis construction is
the exception rather than the rule, as many
stereo enthusiasts have found out from experience. The fact is that only Fisher has been
able to produce high-power integrated receivers of consistently first-rate performance
- totally free from overheating or other lifeexpectancy problems and in every way comparable to separate-component systems. The
800-8 has actually aroused as much enthusiasm among the most advanced audio perfectionists as among less technically-inclined
music· lovers.
.
Everything about the Fisher 800-8 was con ceived with today's most sophisticated engineering standards in mind. The wide-band
FM section has been designed for Multiplex
from the ground up, with t.he extra sensitivity
and absolute stability required for genuinely
distortion-free FM Stereo reception. The
I HFM Standard sensitivity rating is 2.5 mi~ro­
volts. The AM tuner is adjustable for either
'sharp' or 'broad' bandwidth and has a sensitivity of 5 microvolts for 2 watts output. The
power amplifier is capable of 65 watts IHFM
music power output at less than 0.8% harmonic distortion-321f2 watts per stereo
channel. FM Stereo reception is greatly facilitated by the exclusive STEREO 8EAM, the
ingenious Fisher invention that shows instantly whether or not an FM station is broadcasting in Multiplex.
Ask your nearest authorized Fisher dealer for
a demonstration of the 800-8. See for yourself that it is the answer to the requirements
of stereo in moderate space and at moderate
.
cost, without the slightest compromise in
quality. Price $429.50*. The Fisher 500-8,
virtually identical to the 800-8 but with FM
only, $359.50 * . Cabinets for either, in walnut
or mahogany, $24.95*.
FREE! $1 .00 VALUE! The Fisher
Handbook, a lavishly illustrated
40-page reference guide, idea
book and component catalogue
for custom stereo installations .FISHER RAD 10 CORPORATION
21-29 44th Drive
Long Island City 1, N. Y.
Please send tree 40-page Handbook, complete
with detailed specifications on the R-200 tuner.
Name!___________________________
Address' ________________________
i
I
:
I
I
I
I
I
I
City
70ne~tate
:
____________________________ .2!l,.!.o..! _J
THE FISHER
-
PRIC E S S LI GHTLY HI GHI:R IN THE FAR W ES T. EXPORT: FISliER . RAOIO INTERNATIONAL, I NC •• LO NG ISLANO CITY 1, N. Y. CANAOA, TR I -TE t.. ASSOC IATES, LTD •• WI LLO WOA L E. ONT .
AUDIO
•
NOVEMBER, 1962
9
impressive studio during the wee hours to
see how they coped with the cleaning ladies'
conversation. (The booth was not enclosed
-right out ill the main second floor reception hall.) I did look in during the first daytime moments and I must report a sad
observation. WtFM's large public stereo
monitor speakers were out of phase. Maybe
they fixed them later. Anybody notice¥
AUDIO ETC.
.dw.... Talnal. Canbv
Transistor Hi-fi
What's New, What's Fantastic?
of the old Audio Fairs in New York, when the idea
of a hi-fi show was brand new, I used
to make a report each year on my general
impressions of the big event-as soon as I
had sufficiently recovered from the annual
prostration it induced_ Took me weeks. Today's annual New York event, under IHFM
sponsorship, is a somewhat different affair_ For one thing, it's bigger. Hi-fi is
bigger_ For another, it's quieter. Yesquieter. Anll so I recover sooner.
For many a year I simply could not understand how any management of a hi-fi
show could expect people to come and p ay
money to hear fifty musical sources all going full blast at the same time. I gave up
trying to understand long ago, because p eople did pay. They still do. But now, though
the corridors of our show continue to rock
and reel with polytonality, the individual
rooms are at least semi-soundproof. The
walls do seem to cut out most of the highs
and middles that attempt passage from one
booth to the next. Only the low bass seems
to have X-ray penetration. As one moves
f rom exhibit to exhibit, one is merely
aware of a complex tissue of secondary
rhythms-obscure thumps and bumps, rumbles, distant poundings, slow crumbling
noises as of concrete being pulverized,
against the immediate foreground music
of each demonstration. Not too devastating.
It's an odd effect, even so. I am reminded
of a near-relative to it that has been occurring for nearly forty years-live-in Carnegie Hall. Every so often, there, in the
midst of a pianissimo, one suddenly becomes aware of a strange subterranean
musical rhythm, a kind of sonic earthquake,
as though some i=ense giant were witlessly shaking bongo clubs on a huge subsonic drum, zanily out of time with the
stage music. It's a giant all right. The
BMT subway, right next to the hall.
Evidently, the complete blocking of lowfrequency sound is one of the toughest of
acoustical propositions, whether in concert
halls, hi-fi booths, or inside a pair of earphones. Anybody can stop highs. Luckily
for the IHFM, it is the highs, multiplied
and mixed, that kill off show customers,
and that used to prostrate me for days.
Musical polysaturation. The lows we can
all take.
B
ACK IN THE EARLY DAYS
Two Dimensions
What was new, then, at this year's New
York show~ The eternal question! The eternal official answer is always the same, of
course. Everything. Like what's new in this
year's 1963 autos. Totally new, as they al-
10
ways are. So say the ads_ In actuality, most
of the typical 1963 auto is old, repeated
out of respectable, solid, long-time designing. Maybe 95 per cent. And it is the old,
of course, that makes our 1963 hi-fi product
the mature product it is. At a good guess,
we get maybe 5 per cent genuinely significant innovation each year, not counting
minor improvements. Good. As with solid
income from good investments, there should
not be much more than that in a mature
industry such as ours.
There are therefore very few 1963 sensa- .
tions in hi-fi, but a million steady improvements and several significant trends. One
thing that was emphatically not new this
year was any dimension in the literal sense,
in spite of our show's somewhat less than
inspired slogan, "a new dime nsion in
sound." We've had one dimension in mono
for almost a century. We've had two, sideto-side and in-and-out, making our stereo
sound realistic, for a good number of years
already. The third dimension, up-and-down,
was not to my knowledge added this year
by any recording firm, whether for tape or
disc. We're still sticking with two dimensions, thank you.
The slogan, presumably, referred in a
more figurative way to one of the big 1963
trends-FM stereo broadcast componentry.
I suppose this does add a new dimension
for those who haven't heard it before. And
a lot of p eople will be hearing it, I quickly
discovered.
FM Stereo Tuners
That, in fact, was Significant Trend No.
1, quite aside from slogans and advertisi~g
enthusiasm. There was, indeed, a very blg
trend towards stereo in the tuner field, all
the way from the alligator stereo portables
to the custom stereo music centers of the
wall-filling sort. The machines were at the
show in force-and they brought with them
a new problem: how to demonstrate stereo
broadcast sound at a hi-fi show. It was a
problem all right. Though Mr. Harman's
Jerrold people broke their neck working to
get a genuine FM-stereQ> signal out of the air
and into the Trade Show building, th e
problem was understandably not too well
solved. All that steel round about-and
only a few blocks distant, the Empire State
tower bristling with adjacent-channel signals, to be wave-trapped away.
At least we had plenty of FM-stereo going out of the building. Also FM mono.
That's easy: it goes on wires. WtFM
(that's correct, Mr. printer ) broadcast a
stereo marathon 24 hours a day direct from
the show j I didn't get to visit th e station's
The other big trend, Significant Trend
No. 2 for 1963, was that towards a new
wave of transistorized hi-fi components. As
a major trend, at least, this was fundamentally new though the use of transistors
in hi-fi equipment isn't exactly an innovation. What interested me most in the new
models was a clear change in emphasis, as
compared with the first transistor hi-fi of a
few years ago.
Then, the pioneer products in the field
were designed to emphasize the same sort
of thing that the pocket transistor radio
had featured-as well as satellite and missile transistorization. Unbelievably small
size. Light weight. Low current drain. Low
heat production. Low-impedance outputs,
minus transformers. These things were
surely revolutionary, but they came to us
then along with a package of very serious
problems. Hi-fi out of transisto~s wasn't
going to be so simple, it began to. appea:r.
The early equipment was, to sum It up In
non-engineering terms, erratic and untrustworthy despite noble efforts. The missilecomputer-satellite designs didn't seem to
work very well in our rather special area.
As I remember, one of my early transistor amplifiers eventually blew up in a spectacular short. Another leaked its guts all
over the floor. (The transistors themselves
didn't do it, but the attendant circnitry
and lay-out led to the secondary failures.)
Moreover, the sound was variably curious
and odd from these instruments. I'd hate
now to have to characterize it, but it just
wasn't like conventional hi-fi.
Aud there was the noise, the steady hiss
and the sputters and what-not, taking over
from the hum that was absent. Almost as
bad. These things and more were reflection.
of the agonizing reappraisals then going
on in the transistor circuit area as the new
devices were applied to hi-fi functions where
tubes had been used before. Tubes are
tubes and transistors are something elseto a degree that evidently could not be appreciated lmtil the hi-fi industry's engineers had become directly involved in specific designs.
So, for several years, we have heard relatively little of transistor hi-fi. Now, the
new second wave has arrived. And the emphasis, after the careful and long-continued
reappraisal, is also new.
No longer is it on the extremes of small
size, current economy and so on. Instead,
the urge is now directly and forcibly towards the ultimate intent in any sort of
hi-fi equipment-sheer quality of sound.
This time, the transistor has not only caught
up with conventional tube circuitry but has
apparently forged ahead in spectacular
f ashion. What counts, now, is the specsfantastic. Go look and listen! Square waves
that (as our editor observed to me) are
actually ''better'' in the output than the
input. Limpidly pure amplification from
AUDIO
•
NOVEMBER, 1962
How to install
(1) an FM stereo tuner with Multiplex,
(2) an AM tuner with variable bandwidth,
(3) a stereo master control center, and
(4) a 65-watt stereo power amplifier,
all in 20 seconds:
Take a Fisher 800-8. Connect your speaker wires to it. Plug it in.
Yes. That's all it takes to get the Fisher 800-8
ready to play. This famous integrated stereo
receiver incorporates four of the world's finest stereo components - allan one superb
chassis. The entire unit takes up only 171/2
inches of shelf space and, most remarkable
of all, it is only 13 1/2 inches deep.
To include all the 'electronics' of a topperformance stereo system in a single unit
is no small engineering feat. High quality
combined with single-cha ssis construction is
the exception rather than the rule, as many
stereo enthusiasts have found out from experience. The fact is that only Fisher has been
able to produce high-power integrated receivers of consistently first-rate performance
- totally free from overheating or other lifeexpectancy problems and in every way comparable to separate-component systems. The
800-8 has actually aroused as much enthusiasm among the most advanced audio perfectionists as among less technically-inclined
music· lovers.
Everything about the Fisher 800-8 was conceived with today's most sophisticated engineering standards in mind. The wide-band
FM section has been designed for Multiplex
from the ground up, with the extra sensitivity
and absolute stability required for genuinely
distortion-free FM Stereo reception. The
'1HFM Standard sensitivity rating is 2.5 mi<;:rovolts. The AM tuner is adjustable for either
'sharp' or 'broad' bandwidth and has a sensitivity of 5 microvolts for 2 watts output. The
power amplifier is capable of 65 watts IHFM
music power output at less than 0.8% harmonic distortion-32l!2 watts per stereo
channel. FM Stereo reception is greatly facilitated by the exclusive STEREO 8EAM, the
ingenious Fisher invention that shows instantly whether or not an FM station is broadcasting in Multiplex.
Ask your nearest authorized Fisher dealer for
a demonstration of the 800-8. See for your- ·
self that it is the answer to the requirements
of stereo in moderate space and at moderate
cost, without the slightest compromise in
quality. Price $429.50*. The Fisher 500-8,
virtually identical to the 800-8 but with FM
only, $359.50*. Cabinets for either, in walnut
or mahogany, $24.95*.
-----------------------
~-;------,
FREE! $1.00 VALUE! The Fisher
Handbook, a lavishly illustrated
40-page reference guide, idea
book and component catalogue
for custom stereo installations .
FISHER RADIO CORPORATION
21-29 44th Drive
Long Island City I, N. Y.
Please send free 40-page Handbook, complete
with detailed specilications on the R-200 tuner.
Name_________________________
Address _______________________
____________________________
City
70ne~tate
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THE FISHER
·PRICES SLIGHTLY HI G HER I N T HE FAR W ES T. EXPO R T: F ISIIER , RAD IO INTERNATIONAL, "IN C . , LO NG I SLAND CITY I, N . Y. CANADA: TAI·TEL ASSOCIA TES. LT O.: WILLOWDA LE, ONT.
AUDIO
•
NOVEMBER, 1962
9
AUDIO ETC.
.dw..... Talnal. Canb¥
Wha t's New, Wha t's Fantastic?
ways are. So say the ads_ In actuality, most
of the old Auof the typical 1963 auto is old, repeated
dio Fairs in New York, when the idea
of a hi-fi show was brand new, I used out of respectable, solid, long-time designto make a report each year on my general ing. Maybe 95 per cent. And it is the old,
of course, that makes our 1963 hi-Ii product
impressions of the big event-as soon as I
had sufficiently recovered from the annual the mature product it is. At a good guess,
prostration it induced. Took me weeks. To- we get maybe 5 per cent genuinely signifiday's annual New York event, under IHFM cant innovation each year, not counting
sponsorship, is a somewhat different afminor improvements. Good. As with solid
fair. For one thing, it's bigger. Hi-fi is income from good investments, there should
bigger. For another, it's quieter. Yes- not be much more than that in a mature
quieter_ An'} so I recover sooner.
industry such as ours.
For many a year I simply could not unThere are therefore very few 1963 sensaderstand how any management of a hi-fi tions in hi-fi, but a million steady improveshow could expect people to come and pay ments and several significant trends_ One
money to hear fifty musical sources all gothing that was emphatically not new this
ing full blast at the same time. I gave up year was any dimension in the literal sense,
trying to understand long ago, because peo- in spite of our show's somewhat less than
ple did pay. They still do. But now, though
inspired slogan, "a new dime nsion in
the corridors of our show continue to rock sound." We've had one dimension in mono
and reel with polytonality, the individual for almost a century. We've had two, siderooms are at least semi-soundproof. The to-side and in-and-out, making our stereo
walls do seem to cut out most of the highs sound realistic, for a good number of years
and middles that attempt passage from one
already. The third dimension, up-and-down,
booth to the next_ Only the low bass seems was not to my knowledge added this year
to have X-ray penetration. As one moves by any recording firm, whether for tape or
from exhibit to exhibit, one is merely disc. We're still sticking with two dimenaware of a complex tissue of secondary sions, thank you.
rhythms-obscure thumps and bumps, rumThe slogan, presumably, referred in a
bles, distant poundings, slow crumbling more figurative way to one of the big 1963
noises as of concrete being pulverized, trends- FM stereo broadcast componen try.
against the immedi ate foreground music I suppose this does add a new dimension
of each demonstration. Not too devastating. for those who haven't heard it before. And
It's an odd effect, even so. I am reminded
a lot of people will be hearing it, I quickly
of a near-relative to it that has been occur- discovered_
ring for nearly forty years-live-in Carnegie Hall. Every so often, there, in the
FM Stereo Tuners
midst of a pianiSsimo, one suddenly beThat, in fact, was Significant Trend No.
comes aware of a strange subterranean
musical rhythm, a kind of sonic earthquake, 1, quite aside from slogans and advertis~g
as though some immense giant were wit- enthusiasm. There was, indeed, a very bIg
lessly shaking bongo clubs on a huge sub- trend towards stereo in the tuner field, all
sonic drum, zanily out of time with the the way from the alligator stereo portables
stage music. It's a giant all right. The to the custom stereo music centers of the
wall-filling sort. The machines were at t he
BMT subway, right next to the hall.
Evidently, the complete blocking of low- show in force-and they brought with them
frequency sound is one of the toughest of a new problem : how to demonstrate stereo
acoustical propositions, whether in concert broadcast sound at a hi-fi show. It was a
halls, hi-fi booths, or inside a pair of ear- problem all right. Though Mr. Harman's
phones. Anybody can stop highs. Luckily Jerrold people broke their neck working to
get a genuine FM-stereo< signal out of the air
for the IHFM, it is the highs, multiplied
and mixed, that kill off show customers, and into the Trade Show building, the
and that used to prostrate me for days. problem was understandably not too well
Musical polysaturation. The lows we can solved. All that steel round about--and
only a few blocks distant, the Empire State
all take.
tower bristling with adjacent-channel signals, to be wave-trapped away.
Two Dimensions
At least we had plenty of FM-stereo go What was new, then, at this year's New ing out of the building. Also FM mono.
York show' Tile eternal question! The eterThat's easy: it goes on wires_ WtFM
nal official answer is always the same, of
(that's correct, Mr. printer) broadcast a
course. Every thing_ Like what's new in this stereo marathon 24 hours a day direct from
year's 1963 autos. Totally new, as they althe show; I didn't get to visit the station's
B
ACK IN THE EARLY DAYS
10
impressive studio during the we~ hours. t~
see how they coped with the clearung ladies
conversation. (The booth was not enclosed
-right out iu the main second floor reception hall.) I did look in during the first daytime moments and I must report a sad
observation. WtFM's large public stereo
monitor speakers were out of phase. Maybe
they fixed them later. Anybody notice'
Transisto r Hi-fi
The other big trend, Significant Trend
No. 2 for 1963, was that towards a new
wave of transistorized hi-fi components. As
a major trend, at least, this was fundamentally new though the use of transistors
in hi-fi equipment isn't exactly an innovation. What interested me most in the new
models was a clear change in emphasis, as
compared with the first transistor hi-fi of a
few years ago.
Then, the pioneer pr o ~ucts in t he field
were designed to emphaSIze the same sort
of thing that the pocket transistor radio
had featured-as well as satellite and missile transistorization. Unbelievably small
size. Light weight. Low current drain. Low
heat production. Low-impedance outputs,
minus transformers. These things were
surely revolutionary, but they came t~ us
then along with a package of very senous
problems. Hi-fi out of transistoI:s wasn't
going to be so simple, it began to . appe~r.
The early equipment was, t o sum It up III
non-engineering terms, erratie and untrustworthy despite noble efforts. The missilecomputer-satellite designs didn't .seem to
work ver y well in our rather speCIal area.
As I remember, one of my early transistor amplifiers eventually blew up in a spectacular short. Another leaked its guts all
over the floor. (The transistors themselves
didn't do it, but the attendant circnitry
and lay-out led to the secondary failures. )
Moreover, the sound was variably curious
and odd from these instruments. I'd hate
now to have to characterize it, but it just
wasn't like conventional hi-fi.
And there was the noise, the steady hiss
and the sputters and what-not, taking over
from the hum that was absent. Almost as
bad. These things and more were reflections
of the agonizing reappraisals then going
Oll in the transistor circuit area as the new
devices were applied to hi-fi functions where
tubes had been used before. Tubes are
tubes and transistors are something elseto a degree that evidently could not be appreciated until the hi-fi industry's engineers had become directly involved in specific designs.
So, for several years, we have heard relatively little of transistor hi-fi. Now, the
new second wave has arrived_ And the emphasis, after the careful and long-continued
reappraisal, is also new.
No longer is it on the extremes of small
size, current economy and so on. Instead,
the urge is now directly and forcibly towards the ultimate intent in any sort of
hi-fi equipment- sheer quality of sound.
This time, the transistor has not only caught
up with conventional tube circuitry but has
apparently forged ahead in spectacular
fashion. What counts, now, is the specsfantastic. Go look and listen! Square waves
that (as our editor observed to me) are
actually "better" in the output than the
input. Limpidly pure amplification from
AUDIO
•
NOVEMBER, 1962
A great tape recorder made greater:
1. New professional studio recording hysteresis-synchronous capstan motor: 24 stator slots
for ultra-smooth drive, ultra-quiet and vibrationless professional bearing system.
2. Two new take-up and rewind reel motors, both extra-powered for effortless operation.
3. New cored-out steel capstan flywheel with all the mass concentrated at the rim for improved
flutter filtering.
4. New optimally desi~ned capstan drive belt brings wow down to negligibility.
5. New relay provides instantaneous extra power to the take-up reel motor at start to minimize tape bounce. Provides near-perfect stop-and-go operation and eliminates any risk of
tape spillage when starting with a nearly full take-up reel.
6. New automatic end-of-tape stop switch cuts off take-up reel motor power. Also permits
professional editing techniques, whereby tape being edited out runs off the machine while
you are listening to it.
7. Playback preamps remain"on"during stop-standby mode to permit cueing.
8. Recording level adjustment during stop-standby.
9. Shock-absorbent helical spring tape lifters practically elim inate tape bounce at start of fast
winding.
And All These Well-known RP-IOO Features:
Separate stereo 1/4 track record and playback heads permitting off-the-tape monitor and true
sound-an-sound recording ; separate transistor stereo record and stereo playback amplifiers
meeting true high fidelity standards ; monaural recording on 4 tracks; digital turns counter;
electrodynamic braking (no mechanical brakes to wear out or loosen); all-electric pushbutton transport control (separate solenoids actuate pinch-roller and tape lifters); unequalled
electronic control facilities such as mixing mic and line controls, two recording level meters,
sound-an-sound recording selected on panel , playback mode selector, etc. Modular plug-in,
construction.
9
New
Featllres
Now'
In The
New
EICO RP100
Trallsistorized
Stereo I Mono
4-Tracl{
Tape Deck
Semikit: Tape transport
ilssembled and tested;
electronics in kit form $299.95
Factory-assembled: Handwired
throughout by skilled
American craftsmen $399.~5
An original, exclusive EICO
product designed and
manufactured in the U.S.A.
(Patents Pending)
Carrying Case $29.95
Rack Mount $9.95
Wow and flutter: und e r 0.15% RM S a t 7'/, IPS; und e r 0. 2% RM S at 33/4 IPS. Timing Accuracy:
± 0.1 5"10 (±3 seco nds in 30 minutes). Frequency Response : ± 2db 30-1 5,000 cps at 7'/' IPS,
55d b signal-to-n o is e ra lio; ± 2db 30-10,000 cps at 33/ 4 IPS, 50db signal-to-noise ratio. Line
Inputs Sensitivity: 100mv. Mike Inputs Sensitivity : 0.5mv.
New Stereo FM MULTIPLEX TUNER ST97
Semi·Kit $99.95
Wired $149.95
Includes Metal Cover and FET
•Another brilliant example of EICO's no·compro·
mise engineering, the new EICO ST97 combines the features of station·monltor
FM·AM Stereo Tuner ST96
quality and fringe·area reception capabilities with exceptional ease of assembly
Kit $89.95 Wired $129.95
for the klt·builder. No test or alignmenf instruments are needed. The two most
Includes Metal Cover and FET
critical sections, the front·end and the 4,IF stage circuit board, are entirely prewired and pre·aligned for best performance on weak signals (fringe area r~ception).
The front·end is drift-free even with AFC defeated. The four IF stages and 1MC·wide
ratio detector achieve perfect limiting, full-spectrum flat response, very low dis·
tortion, and outstanding capture ratio. The 10·stage stereo demodulator-EICO's
famous zero·phase·shift filterless detection circuit (pat. pend.}-copes successfully
70·Watt Integrated Stereo Amplifier with all the problems of high fidelity FM stereo demodulation and delivers utterly
ST70 Kit $99.95* Wired $149.95' clean stereo outputs. Excellent sensitivity, selectivity, stability, separation and
40·Watt Integrated Stereo Amplifier clean signal add up to superb fringe-area reception. The automatic stereo indicator and station tuning Indicator travel in tandem on twin slide·rule dials.
ST40 Kit $79.95* Wired $129.95 * Antenna Input: 300 ohms balanced. IHFM Usable Sensitivity: 3p.V (30 db quieting),
* Includes Metal Cover
1.5p.V for 20db quieting. Sensitivity for phase-locking (synchronization) In stereo:
2.5p.V. Full Limit ing Sensitivity: 10p.V. IF Bandwidth: 280kc at 6 db pOints.
Ratio Detector Bandwidth: 1mc p.p separation. Audio Bandwidth at FM Detector:
Flat to 53kc discounting pre-emphasis. IHFM Signal-to·Nolse Ratio: -55db. IHFM
Harmonic Distortion: 0.6%. Stereo Harmonic Distortion: less than 1.5%*. IHFM
1M Distortion: 0.1%. ·Output Audio Frequency Response: ±ldb 20cps-15kc.
IHFM Capture Ratio: 3db. Channel Separation: 30db. Audio Output: 0.8 volt. Output
Impedance: low Impedance cathode followers. Controls: Power, Separation, FM
Tuning, Stereo·Mono, AFC·Oefeat.
E xport Dept .• Roburn Aa:enc1el
Listen to 'the EICO Hour. WABC · FM. N. Y. 95. 5 Me. Mon. -Frl.. 7 :15-8 P .M.
AUDIO
•
NOVEMBER, 1962
Over 2 MILLION EICO Inltrumentsln use.
Most EICO Dealers offer budget term ••
Add 5% In West.
®1962 EICO Electronic Instrument Co. Inc .
3300 Northern Boulevard. L. I. C.• I. N. Y.
iEiC0,"33iiON. m;d.;-L:i:-C:1",N:Y:A-lll
I 0 Send free 32-page catalog & I
I
I dealer's name
I 0 M~F~ ~~~ ~~i~~gel Ge~~I~~~Ok2Jg I
I for postage & handling.
I
I Name
I Address
I
I City
I
I
I
79nll-State__
I
I0000- _ _ _ _ _ _ _ _ _ _ _ ...
*Actual distortion meter reading of derived
left or tight channel output with a stereo FM
signal fed to the antenna input terminals.
Inc . • 431 Greenwicb St .• New York 13
11
practically zero cycles to practically megacycles. Noise 'way down and out. And th e
indications a re that, this time, we can
count on r eliability too.
Not fo r nothing has th e literatnre b een
fu ll of transistor circuitry these last f ew
years.
The ex ternal attributes of tra nsistors are
st;ll present and advantageous, though now
of secondary importance. Size still co unts
fo r something; a transistor preamp-control
un it is perhaps two thirds or even a half
the size and weight of a n equivalent tubed
model. Enough. We ar en't shooting missiles
and satellites and we don't yet depend on
solar batteries. The other attributes are
also brought to your notice in these new
models. No output t ransformers, again.
(But a whoppingly heavy power transf ormer.) Low heat, which is important in
a power amplifier, of course, t hou gh not so
vita l in a preamp, which norm ally rUllS
cool. Low current: useful enough. But quality is the transistor by-word. And quali ty
is definitely a new dim ension ill transistor
hi-fl.
Professional 4-speed turntable
Ultra-compl iance
Double turntable mechanism
A double turntable system is adopted for the
professional performance.
The combination of a beautifully-finished, 2 kg
flywheel and a stout, heavy.duty motor ens ures
the top-notch quali ty.
Instant start-stop mechanism
The double turntable system a llo ws in stant startstop actio n by th e shift of a leve r w ithout
disconnecting th e powe r lin e.
It is especiall y convenient when you wish to play
a record from halfwa y or to start \\·itho ut dela y
of time .
Superb speed change mechanism
Drive motor
In the cam assembly used is a roller of precision
finish which ensures smo oth and durable oppra ·
ti o n . The fine adj ustment of a magnetic system
s moo thl y varies th e speed in a wide ran ge.
A powe rful , 4·pole condenser motor is of a
completely new design for the heavy.duty use.
Any low·output magnetic ca rt ridge ma y be easil y
used as the leakage flux of magnetic current is
negligibly low.
Specifications
drive motor.
turntable .
. .. ca pacitor·start 4· polc ind uction type
_ _double , 35cm, 2kg
speed _
. 4 speeds
fin e adjustment .
power line.
. magnetic system
. 85-117V 50 or 60 cycles
S I N ratio.
. more than 50 dB
wow.
_ less than 0.2%
power consumption .
.7W
dimension of panel .. . _477mm X 380mm
Unique stroboscope
An unique illuminated stroboscope with a mirror
s pec ia ll y optically trea ted is ext remely convenient.
The possibility to check the speed of turntable
while playing a record makes th e unit most
a ttractiv e.
NEAT
NEAT ONKY O DENKI CO., LTD.
4. I-chom., Kanda. Hatago-cho, Chiyod. -ku,
Tokyo, Japan
SOLE U.S. AGENTHarold D. Weiler, West Street, Harrison, N. Y.
12
To be sure, th ere was one contiJlUing
trend at New York this f all which almost
rates as Trend No.3, that towards the ever
smaller, lighter, higher-compliance pickup
cartridge. This has been going on for quite
a while. 'l'his year 's emphasis is on more
of th e same.
Now, everybody's compliance figme, if it
is to look like anything, just be wangled
up into the 20's (2 0 x 10- 6 ) . And everybody's st y Ius force must be down in the
less-than- a-gram r egion, combined with a
~uitable a rm. One 1963 cartridge goes aUout (followin g after the sensational ADC
cartridge) to claim a quarter-gram playing
fo rce and a compliance of 25. I saw a
brace of impressive displays and picked up
some pe rsuasive liter ature concerning this
one but, since th e ca rtridge itself didn't
seem to be in evidence, I decided it could
not quite constit ute a Trend-y et.
Just wh ere all this ca rtridge compliance
business is leading us to I'm not sure. P eople's big, clumsy hands haven't chauged.
Records are still a foot wide and most arms
still fea ture the wide-range half-inch
mounting h oles inside big shells, or "heads."
The whole system except th e stylus and
generator elements r emains big and clumsy
a nd eyen dyn amic balancing plus viscous
mounting hasn't made up fOl· it. Not for
manual-play, anyho,Y.
Manual-play
It seems to me tha t a r eally lightweight,
low-mass over-all system must necessarily
be "no tou ch"-i.e., autom atic, elimin atin g
the fingers; yet in a practical se nse this
can neve r be. Reco rd buyers won't stand
for it . We still want to be able to pick up
t he pickup and lower it oursehes. We want
to choose oU1' musical passages to taste,
visibly ancl quickly . We still, most of us,
have an obstinat e preference f or direct acti on, with t he fingers, as opposed to any
sort of iudiJ'ect lever-lowering of the sty Ius.
We were born with fingers to use, weren't
w e ~ We don't like t o fuss around with
leve rs.
The fly-weight pickup system, th erefore,
mu t stick to finger action, or to a cl ose
AUDIO
•
NOVEMBER, 1962
.,
LEADS
FM stereo mUltiplex came first. Next came our "Astro:'
Good things were getting even better. The 708A "Astro"
is an all-in-one stereo center with five integrated components in a compact 6" x 15" X 131/2 " package: FM, FM
multiplex, AM, stereo preamp, stereo amp .
It's so advanced in concept, circuitry, fe atures and
facilities that we suspect it will remain current for the next
ten years. For example, consider its circuitry. Transistors
in the power stage completely eliminate heat problems.
As a result, the "Astro" plays cool-more than 30 %
cooler than conventional units. In this respect, the "Astro"
is the first truly practical stereo center because excessive
heat generated by ordinary all-in-one units shortens life
and effectiveness of the sub-components, causes drift, sets
up noise and distortion.
As another example, consider its unique binaural headphone facilities that offer the privacy of silent listening
at anytime, without disturbing others. For convenience,
the headphones may be plugged in permanently; a separate switch on the front panel activates the headphones.
Or, consider the fully professional t a pe recording
monitor. With it, you may monitor the source two ways
during recording: the instant signal enters the record head
or directly from tape, the moment it is recorded.
An automatic switching circuit electronically distributes mono and multiplex signals to their respective
channels while a stereo light provides visual indication on
type of reception. These examples are only a sampling of
what the "Astro" has to offer. In this case, seeing and
hearing is believing. Price: $597 .00 including cabinet
and excise tax.
One good thing leads to another. For the listener who
prefers a separate tuner or needs only stereo FM to complete an existing system, there's the new 314A "Electra
Emperor" Stereo Tuner. It is identical in quality and fe atures to the FM and mUltiplex sections of the "Astro"
and is styled to match perfectly with our newly improved
"Electra" Stereo Amplifier. Among its distinctive features ,
it provides a "full-time" monophonic output for feeding
an additional single-channel system on the patio or anywhere in the house. The "Emperor" is priced at $359.00
including cabinet and excise tax.
The new 315A "Electra Empress" Stereo Tuner is the
moderately priced version of the "Emperor:' An outstanding performer at $256.00 including cabinet and excise tax.
TO ANOTHER
- tIJ -
_',' __ _
,_
The 353B "Electra" Stereo Amplifier is recommended
for use with either of these new stereo tuners. The
resulting system will reward you with a quality of sound
possible to achieve only with such perfectly matched and
balanced components. The 353 is a dual channel power
a nd control amplifier with 14 stereo or mono inputs,
6 outputs for all known sources, even microphones and tv.
A matricing network is provided for center stereo speaker
and for driving auxiliary speakers anywhere in the home.
Price: $225.00.
For complete information and specifications, see your Altec Distributor or write Dept. A -I I.
~
AUDIO
•
NOVEMBER, 1962
ALTEC LANSING
CORPORATION
L.":';'___iiiliiiiiiiiiiil.
n
~ \\ / 7 A Subsidiary of
L:::::= U
\..'::/ Ling· Temco· Vought ,lnc.
©1 96 2 A lTEC L A NSING CORPORATION
1515 South Manchester Ave .• Anaheim, Calif.
13
simulation of it, comfortable in the hani\..
Either that, or go all-automatic, eliminating the fingers completely, changer-style.
No compromise is possible_ Nobody, say,
wants to fuss with a miniature manual
lathe, maybe with one little crank to move
the arm across the record and another to
lower the stylus into the groove, ever-sogently. It might work; but few will enjoy
it. Fingers are easier, if clumsier.
That's why so many people turn naturally to records and to manual-play. No
winding, no re-reeling, no number-scales to
set, no blind back-and-forth searching by
ear. Records are qnick and direct. It
doesn't matter that most people can't hit
a visible band separation without making
four or five jabs at the record surface, and
the accidental gouge is commonplace. We
want at least to be able to try for the instant perfect hit. Sometimes we make it,
too.
Don't go around, then, thinking up ways
to eliminate manual play_ You'll eliminate
the disc record as well. Its biggest selling
poin t is its visible instant readiness to play
at the beginning, the middle, or the end.
Not even the perfected record changer has
got around this; record changers now feature "manual play" as a competitive advantage.
Not even the Edison cylinder was able to
sell the indirect-lowering stylns system once
the disc and its freely moving pickup arm
had appeared on the scene. That was nearly
75 years ago.
i
Electron Beam w ith Feedback Tracking?
THE KENWOOD KW-60
I ntegrated AM / FM Stereo Multip lex Tuner
Control-center / 60-wa tt Amplif ier
Fit for a King and Queen in a castle of
music and splendor. That's the Kenwood
KW-60! It's engineered through and
through for quality, beauty and performance ... gives you everything you need
for immediate listening except a pair of
high quality loudspeakers. And best of all
- at a price far lower than any comparable tuner-preamplifier-amplifier on the
market today! You can add turntable, tape
heads, stereo earphones and other refinements at your leisure or as you can
afford them!
Look at these outstand i ng feature s:
FM stereo, FM and AM reception· FM
multiplex circuitry bu i lt-in· 60 watts output power (30 per channel) • Sensitivity:
FM, 1.8 microvolt for 20 db quieting; AM,
11 microvolts for 20 db signal to noise
ratio . • Complete control versati lity incl uding (among others) t one controls,
loudness controls, rumble fi lters, balance
controls, AFC on-off.• Tun ing meters for
14
FM and AM • Handsome packaging with
functional control layout and smart meta l
cabinet in cream and deep brown with
gold f inish panel edging.
The Kenwood KW-60 has the most advanced stereo control center available
anywhere. Its versati lity wi II aston ish you.
You'll be pleased, too, with many ot her
Kenwood engineering and quality features ... see them, and hea r the KW-60
at your dealer's today.
net $249.95
Wr ite di rect f or nearest dealer's name an d
t ech nica l inf orm at ion . Dept. A -l l_
KENWOOD
ELECTRONICS, INC.
21 2 Fifth Avenue, New York 10, New York
3 700 S. Broadway Pl., Los Angeles 7, Cal if .
As for the ever-increasing compliance
and ever-decreasing stylus mass, I thinl<
maybe we're heading towards infinities. An
infinitely compliant stylus point- the limp
rag stylus. It just drags along, trailing out
behind. Alternatively, the stylus of zero
mass. Somebody's bound to arrive at that,
sooner or later_ I might as well anticipate.
How about an electron-beam stylus' Just
take the guts out of an electron microscope
and aim your cathode ray at the groove
walls.
Of course you'll have to track the groove
somehow. Why not a self-correcting feedback lathe circuit, locking the electron
beam into ' the groove' Otherwise you'll
have to fit a supplementary mechanical
tracker for your electron stylus, and it'll
have to be decoupled from the sensing unit,
which mustn't vibrate physically, natch. It
has to float, imperturbably; let the electrons do all the "vibrating!' Rather like
decoupling your car from washboardo and
potholes, this. Not so simple. I like the
feedback tracking idea better.
Electrons are good I They could be a big
improvement over the ancient and honorable (but seldom successful) beam-of-light
pickup. If I'm right, that idea goes back
well into the 19th century, but it still
doesn't work too well. The thing about an
electron beam is that it is already a current, whereas a beam of light is a mere
electromagnetic radiation. The difference
is subtle, I admit. ( Does anybody really
know the difference') But difference or no,
the electron beam doesn't need a photosensitive cell in its circuit to generate electricity. It is electricity. All it needs is a
(Continued on page 81)
AUDIO
•
NOVEMBER, 1962
"I
THIS
IS NO
COMPACT!
54 inches high
9 feet around the middle
'.
That's a lot of speaker system. Enough for what pleases
you . It can whisper or it can bellow. It does both
superbly, and anything in between. So much so that
Hollywood's famous United Recording Corp. (sound
studio for record, tape, film, and tv industries) employs
15 of them. As does Ray Heindorf, musical director of
Warner Bros: production "The Music Man" and holder
of 2 Oscars, who has four right in his living room.
No, this is definitely not a compact. It's a giant, this
A-7 "Voice of the Theatre" by Altec. A full-size speaker
system with quality to match. That's why it belongs in
your home. Unless you are willing to settle for a compact "book shelf" speaker ... and compact sound. Of
course if you are a, critical listener, you'll want your
sound brought to life by Altec; sound so realistically
reproduced, you'll find its equal only in the concert hall.
That much the A-7 will give you, and more. Almost
in direct proportion to your own desire for perfection.
If you insist on hearing the "full sound;' the most subtle
contribution of each instrument, the effortless reproduction of massive orchestrations at concert-hall listening
levels, then the A-7 is for you.
Now here is a hint: you can't make it any smaller, but
you can make it a lot prettier. All it takes is a bit of effort,
some grille cloth, some veneer or paint and you can
transform the A-7 into a custom furniture piece. For
built-in installation, there's nothing so perfect. At only
$285.00 each, it's a wonderful do-it-yourself project . . .
for the critical listener.
However, if you prefer your A-7 sound coming from
a more civilized version, we have several solutions, in
walnut or mahogany. There's the 831A "Capistrano;' a
full-size beauty that offers speaker components identical
to the A-7 in a classically styled cabinet. It stands 30"
high, 47" wide, and is priced at $399.00.
The modern 838A "Carmel" is also a full-size, floorstanding system. It features two 12" low frequency
speakers (instead of the one 15-incher in the A-7) and
the same high frequency section. It's priced at $324.00
with decorator base (shown) extra; standard model
comes with round legs. The "Carmel" is also available
with one low frequency speaker in a model called the
837A "Avalon;' priced at $261.00.
AUDIO
•
NOVEMBER, 1962
ALTEC a3IA "CAPISTRANO"
NEW! AL TEC 841A
"CORONADO" SPEAKER SYSTEM
Apartment,size version ofthefull·size Altec spea ker
systems, the "Coronado" is styled to match a pair
of "Carmels" when used as the center speaker in
an Altec 3·channel stereo system . Recommended
for small apartments where space will not tolerate
larger speakers. The "Coronado" is 30" H, 18" W,
14" D and is priced at $199.50.
Go ahead, convince yourself! The A-7 (and its prettier
mates) are ready to tantalize you now, at your Altec Distributor's. Or, for latest stereo catalog, write Dept. A-llA.
......... ALTEC LANSING
CORPORATION
n
©1 962 AlT EC LANS I N G CO~POR "'TlON
c:::;-;=:l \ \
/ 7 A Subsidiary of
L.!::::= U
~
Ling·Temco·Voughl,lnc.
1515 South Manchester Ave" Anaheim, Calif.
15
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An outstanding TV value! Exclusive Heathkit adva nced-design features include latest
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So give the best in electronic kits, give
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16
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AUDIO
•
NOVEMBER, 1962
ANOTHER HEATHKIT FIRST!
AReal 2-Manual Organ for Only $329.95
Hear It for Yourself!
Send for this Heathkit organ demonstration
record ... listen to the beautiful voices, rich
mellow tone a nd astounding ra nge of expression offered in thi s sensational instrument. Send just 50c to cover cost of handling
a nd postage on this 7"-3373 rpm record .
The exclusive Heathkit version of the all-new
Thomas Transistor Orga n now, for the firs t
time, offers you a real two-manual organ a t
the market-shattering low price of only
$329.95 in easy-to-build kit form! Compares
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units costing well over $700. Features two
37-note keyboards ; 10 true or gan voices ; 13note pedal bass; vari a ble vibrato ; expression
pedal ; vari a ble bass ped al volume ; manu a l
bal a nce control; correctly positioned overhanging keyboards ; built-in 20-watt peak
amplifi er and spea ker system ; bea utifull y
factory assembled a nd fini shed walnut ca:binet.
Kit GD-232 (less bench) .. . no
money dn., as low as $22 mo . .. . $329.95
88 to 108 mc cove ra ge; better th a n 1.25
microvolt sensitivity ; AFC for drift-free FM
reception ; tone control. Factory-assembled
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7lbs.
Kit GR-41 ... no money dn .. $7 mo .. $64.95
NEW FM
Portable Radio
la-tra nsistor, 2-diode circuit ; vernie r tuning ;
AFC for drift-free reception; tone control ;
4" x 6" speaker; built-in antenn a; prebuilt
tuning unit. Battery lasts to 500 Ius. 6 lbs.
Kit GR-61 ... no money dn .,$6 mo .. . $54.95
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NEW FM/FM Stereo Tuner
NEW Heathkit SSB "Six Pack"
Stereo Indica tor light; ph ase control for max.
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PLEASE SEND FREE 1963 HEATHKIT CATALOG
:..:N::.:am"'=-_
e
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Order direc t by ma il or see your Heathkit dealer.
0 Parcel Po st
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Addre ss
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=="'-- - - - - - - - - - -- - - - - -
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ITEM
MODEL NO.
PRICE
--------------------------------------------~
AUDIO
•
NOVEMBER, 19.62
17
EDITOR'S REVIEW
RECORD DISTORTION
HEN FM STEREO first became a reality a yearand-a-half ago, a problem was highlighted
which caused much consternation in the recording industry, and also some consternation amongst
audiofans. It was discovered that many stereo records
were not suitable for simultaneous mono and stereo
broadcast, as is the case with FM stereo. It seemed
that a great many stereo records produced unacceptable levels of 1M distortion when the left and right
signals were summed for mono. We haven't heard too
much about this topic recently, apparently because
the stations have been choosing their recordings carefully.
Engineers, however, have been very busy on this
problem. One well-known engineer who has been working on it is E. R. Madsen of Bang & Olufsen, Denmark. In this issue we are presenting the fruit of his
labors wherein he presents the reason for this distortion, and proposes a method to reduce it substantially.
We don't wish to steal Mr. Madsens' thunder, but
we would like to second the motion. His proposal is
that we standardize the vertical angle for both the
disc cutter and the playback stylus; he points out that
it is the difference between these angles which produces both harmonics and intermodulation. The angle
he proposes as an international standard is 15 deg.
Actually, in the United States, the RIAA (Record
Industry Association of America) has adopted a voluntary standard to this effect in their Bulletin E3. It
reads:
W
4. The reproducing stylus motion shall be tangent
to, or lie in a plane which passes through the record
center, and which is inclined at a nominal angle of
15-deg., clockwise, to a normal to the record at the
stylus tip, as viewed from the record center.
This standard can, of course, go a long way towards
solving the problem. However, it is voluntary and a
number of companies may be reluctant to adopt it.
This is natural since in some cases it requires modification of equipment or even purchase of new equipment, and even if the 15-deg. standard were adopted
by every manufacturer in the United States, what
about the records and cartridges that come from Europe? In the classical field we would guess that European-made r ecords occupy a sizable portion of the
market-place.
Our feeling is that all record companies and cartridge manufacturers will co-operate in agreeing upon
a standard cutting and playback angle in time. Those
of us who have spent so much time and money to r educe distortion in the rest of our system, will most
certainly support this proposal, and hope that it will
be effected as soon as possible.
NEED FOR EDUCATION
In the LETTERS column this month issue is taken
with 1"11'. Dilley (" A condenser microphone mixer,"
October, 1962) concerning his recommendations for
18
matching impedances with condenser microphones.
The people who took issue were right of course-a
condenser microphone needs to look into an impedance
at least five times higher than its own; actually the
microphone is being bridged rather than matched. O~
the other hand it is quite understandable for an engIneer to attempt to follow the standard procedure
which is observed in about every other area where he
faces similar problems. Every other type of microphone needs to be matched. What he missed was that
he was not trying to transfer power, which is the point
of impedance matching. But the problem is that there
is no way of knowing this from the specifications of
the device, since the words of description are precisely the same as with other types of microphones.
(Of course the manufacturers of condenser microphones do supply technical bulletins with their products.) In other words it goes against the entire background and training of most audio engineers to bridge
where he has always matched, especially when the
words associated with the two different procedures are
exactly the same. We offer no solution to this difficulty
other than what the condenser microphone people are
already doing-educate the user.
TRANSISTORS I N TRANSITION
Like old age and taxes, transistors appear to be here
to stay if we read the signs correctly. At the recently
concluded High Fidelity Show in New York the transistor straws were in the wind wherever one turned.
Weare not talking about medium-quality equipment
either; most of the new transistor amplifiers and tuners
were in the high-priced high-quality category. W e
expect to see almost every major manufacturer exhibiting transistor equipment by next year. What
convinced us of this was that a major manufacturer
long considered the stronghold of tube orthodoxy has
taken the plunge; he exhibited a transistor amplifier
this year (developmental model). From now on it is
just a question of time, although there are some who
have felt that the cb,angeover to transistors has been
inevitable for a long time. Anyhow, this is one changeover which will not obsolete existing equipment.
Another trend we noticed at the show was a heightened interest in tape equipment on the part of the
audiofan, and reflected by the introduction of new
tape machines by companies which had not been in
this field before. Also there seemed to be more playback decks available than heretofore.
A surprising, but inevitable, development was the
relative lack of excitement over multiplex equipment.
Apparently audiofans have accepted FM stereo and
are now concerned with other aspects of the problem.
For instance there was great interest in antennas and
other equipment for receiving the stereo signal. It has
become obvious to most if not all audiofans that the
range of multiplex transmission is not as great as
standard FM transmission. We will devote editorial
space to this problem in the future.
(Cont'i nued on page 93)
AUDIO
•
NOVEMBER, 1962
.,
* The hermetically sealed STANTON Stereo Fluxvalve is warranted for a lifetime and is covered under the following patents: U.S. Patent No. 2,917,590;
Great Britain No. 783,372; Commonwealth of Canada No. 605,673; Japan No. 261,203, and other patents are pending throughout the world.
AUDIO
•
NOVEMBER, 1962
19
News from Bell Telephone Laboratories
WE'RE uFINGERPRINTING"
VOICES ••• TO FIND BETTER WAYS
OF TRANSMITTING THEM
Acoustics scientists at Bell Telephone Laboratories study
voices to learn how one voice differs from all others, what
makes yours instantly recognizable to friends and family, and
what the elements of a voice are that give it the elusive
qualities of "naturalness."
To enable us to examine speech closely, we devised a
method of making spectrograms of spoken words. We call
them voiceprints. They are actual pictures of sound, reveal ing the patterns of voice energy. Each pattern is distinctive
and identifiable. They are so distinctive that voiceprints may
have a place, along with fingerprint and handwriting identification, as an important tool of law enforcement.
The shape and size of a person's mouth, throat and nasal
cavities cause his voice energy to be concentrated into bands
of frequencies. The pattern of these bands remains essentially the same despite modifications which may result from
loss of teeth or tonsils, the advancement of age, or attempts
to disguise the voice.
Study of voiceprints and recognition factors is part of our
exploration of new techniques to extract and transmit the
minimum essentials of a person's voice and from these reconstruct the original voice at the receiving end, retaining its
factors of naturalness.
Our ultimate goal, as always, is to learn how to improve
your telephone service and make it a better value.
BELL TELEPHONE LABORATORIES
World center of communications research and development
Word Picture. This is a picture of the
spoken word "you ." By analyzing the
sound with a spectrograph, the Laboratories ' Lawrence G. Kersta makes a print
of the word in graph form. Graph shows
frequency, time taken , and intensity used
in making speech sound .
;
Vertical Tracking A ngleA Source of 1M Distortion
An analysis of the distortio n resu lti ng from th e disc repancy between
the vertical angle at which the record is cut and the vertical angle of
the playback stylus. A proposal is made to standardize these angles.
E. R. MADSEN':'
P
reproduction of stereo records have been
considered from the viewpoint of
reproduction quality previously. M. S.
Conington and T. Murakami of R.C.A.
Victor have analyzed the relationships
and found that when using the 45/45
system and a 90-deg. groove angle with
the ideal playback cartridge, there is no
{lross-modulation between the two channels. Intermodulation and harmonic distortion are identical for the two channels
and are the same as they appear with a
normal hill-and-dale record. If the records are cut with a groove angle of 90
deg. between the two channels, and the
two axes of the cartridge are at right
angles to the movement of the two respective grooves, there will be no crosstalk from one channel to the other. These
are ideal conditions. In the following
discussion it will be shown how unevenly
and confusingly the various makes of
ROBLEMS CONCERNING THE
.• Chief Audio Engineer, Bang and Olufsen, Denmark.
records are cut - a confusion that not
only makes for listening variations of the
many records, but also gives quite a few
headaches to the playback cartridge designer. These problems could be avoided
if agreement could be reached on standardization of disc cutting procedures.
Perhaps the historical background is
partly responsible for the wide disagreement on methods. It should be remembered that the first experiments with
ster eophonic phonograph records began
about 1930. At first the vertical-lateral
system was used, although even at that
time mention was made of the 45/45
system now in use. In a way the two systems are identical, since by suitable
phasing of the two information channels,
it is possible to change from one system
to the other, making it practical to cut
with either system using the same cutting apparatus. Correspondingly, a
pickup constructed for the one system
can, by means of suitable phasing, be
used to play the other system.
PICKUP
STYLUS ANGLE
SHURE
40°
ORTOFON
25°
B& 0
30°
FA IRCHI LD (GL)
35°
FA IRCH ILD (NY)
35°
·GENERAL ELECTR IC
25°
RONETTE
DECCA
~
12°
0°
PICKER ING
15°
ELAC
23°
Fig . 2 . Stylus can t ilev e r angle in a va rie ty of ca rtridg e s.
30
D; 0.5 <PM (S. B. BAUER)
R
M=IO CM/SEC
20
'"
R= 7 . 5 CM
I
;!
Z
0
:E
~
J:
Cl
Z
10
0
~
TR AC KING ANG LE <P- DEG REE S
AUDIO
•
NOVEMBER, 1962
Fig . 1. Th e perce nt
o f s eco nd h ar mo nic a s a f u ncti on o f t ra c k in g
an gl e a nd m odulati o n.
This is not the place to discuss the advantages and disadvantages of one system versus the other, but merely to point
out that from the historic development,
equipment to record and play back stereo
records has been largely derived from
the vertical-lateral system. It is this
existing equipment which impedes work
in creating agreement on standards for
the 45/45 system which has been accepted.
Stereo phonograph records only became a reality after the development of
the Westrex stereo disc system. Stereo
records were first made available to the
general public in the United States. The
fundamental work on the method of constructing stereo playback cartridges
therefore came from C. C. Davis' and
J. G. Frayne's description of the Westrex system which was publicized in the
spring of 1958. In June, 1958, the al-
21
50
When:
(B)
LATERAL
(A)
VERTIC AL
VELOC ITY 7 CMtSEC
40
....
?f..
is the variation in tracking
angle in degrees
M is the modulation amplitude
in cm/sec
R is the radius from the groove
to the center of the record in
cm.
q>
30
Z
Z
0
0
;:::
g
;:::
~
20
' ° 0 . 7 MIL
0
0
~
~
10
6
10
7. 5
DI S T ~NC E
12. 5
10
7. 5
IS
FRO M CEN TE R - CM
15
DISTANCE FRO M CEN TER - CM
Fig. 3. Vertical and lateral 1M distortion as a function of the distance from the center
of the record and stylus-tip radius.
ready mentioned work of Corrington and
Murakami in the R.C.A. Review, which
weighed the merits of the vertical-lateral
and the 45/45 system in regard to distortion, favored the latter system.
Since it is impractical to place the
in reality a variation of a considerable
angle from the vertical. In the Westrex
system, this angle is set at 23 deg.
Calculations have been made of the
harmonic distortion which appears when
playing a laterally-modulated phonoAVG. VALUER- 10 eM
M ~ 10 (M/ SEC
SECOND HARMON IC (%)
GROOVE
MOD .
(CW5ECj
,
LEFT · RIGHT
FREOUENCY
RAD IUS
'P'
l e M)
O R 1006
400
8- 10
6. 3
OR 1005
' 00
8-\ 0
6.3
E- V 695 D (78)
1000
7- 9
6
0 . 55
TEST RECORD
CALC.
CUTTI NG
ANGLE
VER T.
l EF T
2
10
C
8
II
8'
0.9
7.S
5
6
8.7
13'
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3. I
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1.4
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RIGH T
WE5TREX 1 A/ B (78)
1000
14 . 5
5. 5
DEC CA 99102 A/ B
1000
10
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1.6
1. 6
DG 99102 Al B
1000
14. 5
8
6
6
II
S'
RGA 12/5(7 1
1000
14. 5
3. 8
0. 8
0. 8
3
24°
Distortion measurements of a
number of test records.
TABLE I.
axis of revolution of the stylus cantilever
exactly at the surface of the record, a
vertical tracking distortion will arise
unless there is a very close agreement
between the angle used by the cutting
head and by the pickup. What is normally referred to as the vertical movement of the tip of the cutting stylus is
graph r ecord with the incorrect tracking
angle. According to B,. B. B auer
("Tracking angle in phonograph pickups," Electronics, March, 1945) the formula for the second harmonic when using
the wrong tracking angle is
D := O.5q>M
R
o LI NE - -,1<'-,'--.,,---<- -- - ' ' - - L - - -- ----'-A:----
Fig . 4. A doublemodulated groove
and the result of
incorrect tracking
angle.
'.
a LI NE
'- 1
M
22
It can be seen that the distortion is independent of the frequency, and only
dependent on the modulation and the
distance of the stylus f rom the center of
the record, and of course the tracking
angle. The formula is computed for a
laterally cut groove with a record rotation speed of 33% revolutions pel' minute. Figure 1 shows the tracking angle
distortion at different places on the record, with a modulation of 10 em/sec. In
a well-constructed tone arm the variation from the correct tracking angle can
be held to within 1 deg., plus or minus;
in other words, in a good playback cartridge it can be demanded that the second harmonic be less than 1 per cent
with normal modulation.
Bauer's formula can also be used for
a vertically cut groove but additional information is required, because the harmonic distortion will depend here to a
great extent on the frequency and on the
radius of the stylus. It should be noted
that the harmonic distortion is always
greater for a vertically cut groove than
for a lateral cut. At 1000 cps it will be
about 5-6 times as great. Here I refer to
the basic work of J. A. Pierce and F. V.
Hunt in the Journal of the Acoustic S ociety of Amel'ica, 1938.
Of the same magnitude, indeed sometimes worse, is the distortion obtained
when playing with the wrong vertical
tracking angle.
Distortion measurements have been
made on a number of test records, using
a B & 0 stereo pickup. The results are
shown in Table 1. The average figures
for the right and left channel, recalculated for all records to 337'3 rpm and
with a modulation of 10 em/sec, and a
distance from groove to record center of
10 em (about the middle of the record)
are shown at the far right. On the basis
of these measurements, and after comparison with the curves of Fig. 1, the
presumed cutting angles for the vertical
cutting are indicated.
H armonic distortion resulting from an
incorrect t.racking angle consists mostly
of second harmonic. The third harmonic
is about 12-15 db down from the second.
We can see from Table I that the
lateral distortion is unimportant in comparison with the vertical so that we may
assume the tracking angle is correct for
it. Vertical modulation shows considerable second harmonic distortion, however, dependent on the make of record.
In or der to compare the various records,
recalculation (average value for both
channels at 33% rpm) has been made in
AUDIO
•
NOVEMBER, 1962
0
PICKUP
B
D
R
5
LA TERAL
VERTICAL
)
4
~
LEFT
- .}
RIGHT
~
37
25
28
15
7. 5
10
10
18
55
40
30
4. 5
40
30
25
7
20
10
12
5
40
30
25
LA TERAL
.'1 )\
5
60
40
50
16
8
12
12
24
65
55
60
5
60
35
40
15
40
50
30
8
75
50
50
10
25
15
20
15
12
10
10
10
23
60
40
50
40
15
25
10
12
12
12
10
45
25
30
10
40
20
25
16
25
15
15
23
72
28
25
lD
40
25
35
10
20
20
30
10
70
50
50
F
50
DISTAN CE FROM CEN TER EQ UAL S 10 C M
10 CM/ SEC
<0
VE RTI CA L
LEFT
RI GH T
30
Fig. 5. 1M d is t o rtion as a f unction
of vertica I tracking ang le and reco rd in g leve l.
LA TERAL
VERTICAL •
LEFT
RIGHT
\
LATERA L
VE RTICAL
LEFT
RIGH T
)
~I
:I
0-
e
<{
~
z
S?
8
0
~
§
<{
Z
0
!2
0
'CWSEC
Intermodulation of a
number of cartridges.
TABLE II.
VER TIC AL TRACK ING A NGLE
-
the next-to-Iast column. The difference is
obvious between records from Decca, at
the one extreme, with RCA, Westrex,
and Electro-Voice at the other.
From the viewpoint of the playback
cartridge designer, a fairly large vertical
cutting angle would be preferable, as it
is necessary to allow space for the moving elements, whose center of rotation
must lie above the record surface.
The angle of the stylus cantilever to
the record surface of several pickups
has been determined by measurement and
is shown in F ig. 2. It is evident that
there is as much difference here as with
the various cutting angles for the records-the result of a lack of standards
for r ecording.
As mentioned earlier, the most important harmonic distortion is second
harmonic due to the incorrect vertical
tracking angle. In the case of groove
modulation with two tones, an intermodulation product appears as well. As far
as is known no previous theoretical calculation has been made of the size of
this product as a function of the tracking angle. An attempt to make such a
calculation will therefore be made here.
If you first assume a correct vertical
tracking angle, there is considerably
more intermodulation distortion in playing a vertically modulated groove than
is the case with a laterally modulated
groove. Corrington and Murakami give
the f ollowing formula:
DEGREE S
where:
U 1 is
the lowest frequency recorded amplitude in ips
r is the radius of the stylus in
thousandths of an inch
v is the r ecord speed in ips.
With a 33Ys-rpm record,
v
2R 33Ys
60
R is the radius from the stylus tip to the
center of the record.
In F i g. 3 the intermodulation distortion is shown respectively vertically and
later ally with a stylus tip radius of 0.5
mil and 0.7 mil and a recording speed
of 7 em/ sec at various distances from
the center of the record.
As can be seen, the intermodulation is
about 10 times as large in the vertical
channel as in the lateral. Inter modulation
in the later al cutting appears as modulation of the even harmonics, and in vertical cutting it appears as modulation of
db
the odd harmonics. It looks severe, and
it is not improved by an incorrect vertical tracking angle.
In Fig. 4 a vertical double-modulated
groove is diagrammed. We imagine the
groove to be traced by an ideal stylus,
and try to investigate what will happen
due to a wrong vertical tracking angle.
This groove is considered to be cut with
a vertical cutting angle of 0 deg.
The angle for zero transmission of the
lowest frequency is a, the amplitude of
the low frequency is alJ and for the high
frequency a2 • The minimum and maximum values which will be obtained for
az will be found at the points of zero
transmission, which are p and q. The
difference between these values of a~ at
points p and q} divided by the average
amplitude of a ! } multiplied by 100 will
equal the percentage of intermodulation
of the odd harmonics.
In F i g. 4 the areas about points p and
q are shown magnified. at is the amplitude for the high frequency, as it would
be with the correct delineation (cp = 0),
b is the size at point p with delineation
under the angle Cp, and c the size at point
q with delineation under angle cpo
1
1
I
o - -- - - - - ---- 4-,------ - -- - -- --
,,
1
- 10
I
:
-20 .
- 30
~:-'~> :::'--~/
\
,
'\'
/''
I
I
/
" - , '- -
1
1
-5
o
+5
GROOVE 90° IN THE CUTTI NG PLAN E.
C UTTING DIREC TIO N 45/ 45 IN THE
C UTTI NG PLA NE.
x = 45°
y = 45 °
t on x=
-
(I
~~~
t
o
Fig . 6 . Principle of the B & 0 cart ridge .
AUDIO
•
NOVEM BERd962
Fig . 7 . Some ge o metrical relati onships in the ste reo g roove.
23
-1 0
- 20
~
,
- 30
- 10
- 20
,
~
1000 cps
- 20
400
cps ...........
(3 = 16 . S'
V
"""
,,
I
...;
D. G. 99102
....
~
"
- 30
Y
W ith the help of the sine relation used
on triangle MNO, we obtain
A/B
,
/
'"
/"\
'"
and used on triangle MSO,
..-
a g cos a
c=-"--,,-----.,.
cos (a. + <p)
f3 = 8'
'"
Inserting the values for b, c, and Z in
Eq. (1), we obtain
:-- r--- 7. 5'- ~
1000 c ps
I
RCA 12- S- 7 1 A/ B
Fig . 8. Crossta lk
curves for a variety of test reco rds.
/
/
.'\.
V
/
V
~
~
- -V
1000 cps
- 30
)J .100 %
cos (a + <p
cos (a - <p)
a., which is the angle for the zero
transmission of the low frequency, is
found from
vy2
tana=
- c.
- 10
.....
TELEFUN KEN T 722 13
WESTR EX IA
"" '"0
"
cos (a. - <p) _
cos ((.( + <p)
.-:P
t---"
- 20
1M = [
/'
"....
Z = --'==7===7===~==~
cos (a. + <p) • cos (a. - <p)
/'"
OR 1006
""
,I
- 10
~
/
~ ~ S.7 '
o
cos a.
~
b = a g cos a.
cos (a. - <p)
OR Il - -
/
~OS7
"- --- x-: --- "
"
~
f' .....
-30
::J
~
>=
./
/'
"- ....
/"
\
DJCCA SXL
"-
£'
\,
i
1000 c ps
/"
,
400 cps
\
...
E-~ 69S~
1000 cps
value of Z can be obtained with the integration of a/s delineation value under
the angle <p over a wavelength of the
low frequen cy, which gives :
I
(3 = 25'
;/
h-'
~/
V -V
.;;/ ~
"'~
~~
K l""'-, ~ i-"
f\ ~
.... -,_
'v
."
,
V
k: ~
- ~
- - - - - - CRO SS TALK RIGHT.,. LEFT
- CROSS TALK LEFT - RIGHT
The percentage of intermodulation is
expressed as:
c -b
IM= a Z 100 % E q . (1)
2
Z is a factor that determines the aver-
age amplitude of a2 with delineation
under the angle <po
For small values of <p however,
Z
== - 1- . For
cos
<p
larger angles the correct
V=20 C M/S EC
R=7 . S C M
CUTTI NG ANG LE= 20 '
where v is the effective recording speed
in cm/sec, and c the groove speed in
cm/sec.
Development of the above assumes a
considerable difference in the two frequencies, and that t he sine curve for the
lowest frequency in the points considered can be thought of as a straight line.
The above gives a basis for the determination of the degree of intermodulation as a function of the tracking-angle
fault.
Figure 5 shows 1M calculated for three
different recording levels and a distance
from the record center of 10 cm. The
calculation is valid for intermodulation
of the odd harmonics.
A calculation of the inter modulation
of the even harmonics shows that these
are unimportant in comparison with the
modulation of the odd harmonics.
If Fig. 1 and Fig. 5 are compared it
is seen that considerable harmonic and
intermodulation distortion appears if
the vertical cutting angle and the vertical tracking angle of the pickup are not
the same.
On the basis of two intermodulation
test records produ ced by Ortofon, measurements have been made of a number
of playback cartridges. The results are
in Table II. The principle of the B &
pickup is shown in Fig . 6.
The results are anything but encouraging. From the measured values it is possible to predict with r easonable accuracy
what angle the stylus cantilever makes
with the record surface, if all the data
for the record is known.
The variations in vertical cutting angle
a
Fig. 9 . G ra p hic re prese ntat io n of w hat ha ppens when the stylus angle is different
than t he cutting a ng le . This indica tes t hat the syl us shou ld be tipped b ack rather than
forw a rd a s is co mm o nly believed.
24
(Oontinued on page 88)
AUDIO
•
NOVEMBER, 1962
Let's Talk About
Tape Synchronization
HAL MARGARGLP
The commercially available techniques for coordinating a tape recorder with motion picture film are described and analyzed and a new technique is proposed.
of magnetic
film and tape in this country in commercial quantities the motion picture
producer has used it for sound recording.
The first recorders utilized regular film
stock magnetically coated and, of course,
sync was no problem because of the
"perf" holes. In the quest for more portability, and ever more economy, the synchronized 1,4-in. tape systems reared
their ugly heads. The author is not sure
which system arrived first but his initial
contact was with the 60-cps Rangertone
method.
It may be well to mention here that
some producers use perforated 1,4 -in.
tape but our discussion will include only
the electronic means. We could also mention that a lot of the "old guard" and
some of the young old guard, including
the writer, looked askance towards these
new systems. However, because of the
many millions of feet already used, we
must concede that tape for motion picture recording is here to stay.
The greatest advantage of tape is its
easy adaptation to location, or field, recording. 'I'his article is weighted towards
the portable uses, although studio recording will be mentioned also.
E
VER SINCE THE ARRIVAL
Rangertone System
The Rangertone system developed and
marketed by the late Col. Richard H.
Ranger is perhaps the simplest of all
to use during the recording operation. It
uses a separate head mounted in the
tape path (see F i g. 1) with the slit running 87-deg. out of azimuth from the
normal recording slit. The energy for
this head is applied, without bias, via a
small filament-type transformer with a
series resistor used to adjust the head
current. With a suitable system of relays
and push buttons, or switches, the head is
used for recording, and subsequently for
sync playback. A simple pilot light is
used as a fairly accurate recording indi··
cator. The newer head kits check the signal by providing a cable which plugs
into the regular amplifier of the recorder. Some kits use a miniature meter
* 5705 M"isty Drive, Lanham, Md.
AUDIO
•
NOVEMBER, 1962
Fig. 1. Rangertone sync head mounted on
an Ampex 600 .
to sample the cunent. All in all it is a
reliable method and normally should require a minimum of maintenance.
The disadvantages, however, could be
formidable because the slit length is finite, and the actual part of the tape utilized is very small. This shows up as a
chronic problem of track placement. If
the head is knocked 01' altered in position just slightly and the recorded tape
must be played back on ano ther standard machine, trouble results. The head
of the playing machine either has to be
moved or it must have a manual adj ustment of the vernier type to adjust to th:1
sub-standard track. Most sound-service
studios utilize the vernier-adjust method.
The waveform on the tape is far from
a pure sine wave, probably because no
bias is used, and in some cases can cause
trouble during playback if the shaping
circuits are not functioning properly. If
the tape does not make intimate contact
with the complete head surface near the
slit, the hum problem is aggravated and
can ruin an otherwise good recording
with the harmonics of 60-cps noise. Good
tape contact is sometimes hard to achieve
because the original tape machine was
probably designed for a specific number
of heads, and the "foreign" Ranger head
upsets the tape path. In rare occasions
some r ecorders have to be adjusted to an
unfavorable playback frequency rcsponse to allow for the sync head. In
most cases the installation of the sync
head can be time-consuming and hairpulling job. Many of the newer tape machines have provisions for the addition
of one or more extra heads which makes
installation simpler.
Pilot-Tone System
A newer scheme similar to Rangertone
is the Pilot-Tone Sync System. Developed in Germany and used extensively
for German television, it has now been
accepted by a large producer on this
continent. It utilizes a special head with
the slit oriented exactly perpendicular to
the slits of the audio heads with a gap
length of 20 mils (see Fig. 2). The center of this rather wide gap is placed in
the center of the tape. The sync recording is made using bias that is obtained
. from the local bias oscillator of the tape
. recorder. The sync signal is obtained
from a stepdown transformer, as with
most other systems, or a generator
mounted on the camera in the case of
battery-operated units. The signal-tonoise ratio decreases about the same as
Ranger's "published" figures when measured without, and then with, the applied
sync signal. This system enjoys the same
disadvantages as Ranger in that it necessitates a special head installation, sometimes in an impossible position, and has
Fig. 2. Pilot-Tone Head. Note size <that's the added disadvantage of requiring additional equipment to obtain the higha penny it's resting on) and the 20-mil
frequency bias used. The track placegap length.
25
that each machine must have a special
installation. Producers with a number of
tape machines would rather take along a
"black box" with any machine that is
available. This brings us up to the allelectronic systems utilizing the mechanical and electro-mechanical parts already
on the recorder.
Pic-Sync System
Fig . 3 . 14,000-cps ca rrier genera tor used
in t he Fairchild Pic-Sy nc system. Th is un it
is shown in the cabinet of an Ampex 300.
The most popular application of this
method is the Fairchild Pic-Sync system. Here a 14,OOO-cps carrier signal is
used, modulated at a 60-cps rate with
an SO-per-cent-modulated envelope. This
STANCOR
PS- 84I S
RI I
T1 I NI096 ISOOw
ment problem is, alas, also present and
should be even more acute than with
Ranger's diagonal-slit recording.
usually used to eliminate the 14,000 cps
from the audio going into the record amplifier before the sync-signal injection.
This means another black box or even
modification of the recorder. Recorders
used only for voice frequencies generally
do not need the filter and are able to
make acceptable recordings without it.
Many studio recorders use the 14,000-cps
carrier system and merely bridge the recorder at the output of the low-pass filters which normally feed the photographic recorders. The author chooses to
eliminate the 14,OOO-cps carrier by resonant means in order to preserve the fre-
175 v
• M A TCHED
PA IR
Echelon-Head System
We can now discuss still another
method using a separate head, the echelon head system. In this system the head
is mounted in a fashion similar to the
sync heads with the exception that the
sync signal is recorded on the top and
bottom or, if you will, outer edges of the
tape. The original method utilized a
push-pull arrangement but - later was
changed so that the signal is impressed
equally both top and bottom with the two
slits being slightly displaced from each
other in time only. The recorded signal
can be used either with or without bias.
This method has many of the advantages
of the previously mentioned systems. The
problem of hum pickup does not appear
to be as troublesome as with the Ranger
system, but there is some susceptibility
to tape disfiguration. When using the
large NAB reels, the edge of the tape
sometimes gets a crimp that tends to
make the sync-signal area somewhat critical, whereas it would not affect a fulltrack audio recording. In common with
all special-head systems, the echelonhead method is plagued with tape deformation and excessive dirt problems, and
a disadvantage to some users is the fact
Fig . 4. 30-cps sync genera tor connecte d
t o an Ampe x 60 1. Note t ha t the " bl a ck
box" is gray in t his instance .
26
12AU7
C3
7S -1 30 v
INPUT
6 . 3 V.D . C .
0.6 Y. o . C .
Iw
Sw
"'"
M",
"'-
PL - I
1815
NOTE S,
I. REA CTOR T2 WA S J UN K SO X II 0h UNIT.
UTC 0-1 3 OR HVC-II O R HVC-1 2 COUL D BE
USED WITH POSS IBLE A LTERATION OF C4,
CS, C6 O R C9 .
2. OR IGIN AL PROTOTYPE HAD OVER 3%
THO OUTPUT WITH ABSOLUTELY NO BAD
EFFECT S. WEN T TO I % TO GU ILD THE lIL Y ,
THEREFORE EXPERIMENTING WITH A LE SS
BUSY FILTER IS IN ORDER.
3. WIRING A ND LEAD DRE SS NOT CRITICAL.
4. KEEP THE DIO DE AWAY FR O M THE TU BE
A ND RI.
5 . A LL RE SISTO RS 1/ 2 w EXC EPT RI Sw .
6 . A LL CA PA CITORS 200w.v. EXC EPT C I
3S0w . v .
-
Fig . 5. Schem a ti c of 30-cps sync ge ne ra tor.
signal is injected into the record amplifier at almost any point but usually after
the normal high-frequency tape preemphasis (see Fig. 3). The manufacturer
recommends using a level of from 32 to
3S db below 100 per cent modulation of
the tape. In practice most recordists use
a level around - 20 VU, probably because
they can then "see" it on the normal VU
meter. 14,000 cps is certainly an audio
frequency and can be heard, but because
of the normal 6000- to SOOO-cps cutoff of
photographic recording channels, it is
not very objectionable even at the higher
level. One problem here, as with all systems where the sync is recorded along
with the regular sound, is to keep any
program material from affecting the sync
signal. In practice some cymbal crashes
and even some excessively sibilant voices
do just this. For that problem a filter is
quency response of the program up to,
and beyond, 10,000 cps. In practice the
carrier system works very well in the
studio but some recordists have apprehensions about the sync generator malfunctioning in the field. Other disadvantages are: it is almost a necessity to record at 15 ips for stability at the carrier
frequency; when recording on one machine and playing back on another, both
must be right on azimuth and the 14,000cps signal must be accurate for complete
compatibility. Some studios have vernier
peaking controls to "search" for the
maximum signal on incoming tapes to
be transferred. Then, of course, it is well
known what happens to frequencies over
10,000 cps when dirt or deformed tape
is encountered.
We should perhaps pause a moment
(Continued on page 86)
AUDIO
•
NOVEMB ER, 1962
!
Perhaps two years from now the quality of this
duplicated." . perhaps, never!'
a physically perfect
tape . .. a musically perfect sound ..
,J tape may be
0-
Lu'i ,i r I, C N . ~", I"~: ,'-If.j '>'.! )NOCRAr, CORP
:'..' E'_IH.
,~C.·'·f
. ~ •. N
J "_If
T he value of this resistor depends upon the
impedance of the record head.
4. Proper audio current thr01tgh t he record head. In home tape machines it is
generally accepted that the maximum audio
current going through the record head
should be that which produces 3 per cent
distortion on the tape at frequencies in the
r ange of 250 to 400 cps. For a given
amount of signal voltage applied to the
record head driver, the amount of current
flowing through the r ecord head and therefore the amount of m agnetic flux ultimately
applied to the tape depends on the impedance of the r ecord head.
HERMAN BURSTEIN *
(Note : To facilitate a prompt l'eply,
please enolose a sta1nped, IMlf-addTessed envelope with YOUT question. )
Splicing Problem
Q. I am supeTvisor for ·a small studio for
electronic music at a univeTsity. In our
work we emp loy two Viking Super Pros.
The pl'oduction of electronic music involves much tape splicing. Our work has
been hampered by splicing problems which
I have had difficulty solving. We use Scotch
1.S-mil tape and splicing tape. Our editing
is done on an EdiT all splicing block, and
the splices appeaT to be very good. The
problem is that when a splice meets and
leaves the head group, a temporary waveT
OCCU1'S in the pl'ogTam material. It appears
that the leading edge of the splicing tape
presents a resistance, hence a slight jar, as
the pl'eSS~Lre pad is met. Tapering the leading edge of the felt has only pl'oduced a
slight i1nprovement. Would you have any
suggestions to offer?
A. Are you applying the splicing tape so
that it makes a 45-deg. angle with the
tape or is it at a 90 deg. angle~ The 45-deg.
angle would seem to be preferable, enabling
the splicing tape to make gradual rather
than immediately total contact with the
pressure pads. You could try applying a
tape lubricant, such as is available in a
number of amlio stores, to both the pressure
pad and the spliced portion of the tape.
In subsequent correspondance with this
individual, it turned out that he also obtained an improvement by causing the tape
to approach the heads at a more gradual
angle. This would require installation of
new tape guides.
Mixers
Q. Is it possible to purchase mixers that
will handle a high-level (tuner) as well as
low-level (mike) souTce? Can a high-level
source be f ed into a mixer designed only
for mikes? If I want to mix only two inputs, what is the advantage of a mixer over
a simple Y-adapt01·?
A. There are mixers designed to work
with mikes alone, and others that will aceomodat(' low-level sources on some inputs
and high-level sources on other inputs. If
you feed a high-level source such as a radio
or piezoelectric pickup into a low-level input, there is danger of overloading the first
stage, with consequent distortion. But if
you first reduce the signal of the high-level
source so that it is of about the same order
as a mkrophone signal-not over 20 millivolts or so-and then feed it into the lowlevel input of the mixer, you would be all
right so far as distortion is concerned. On
the other hand, you would be reducing the
input signal in relation to the noise produced by the first stage of the mixer.
28
The advantage of a mixer over a simple
Y-adaptor is that you isolate the inputs, so
that when you change the level of one input
you affect the level of the other inputs very
little if at all.
Preamp A with Deck B
Q. My q~Lestion concerns the advisability
of pt!I'chasing .a tape pl-ea1np by one manufactul'el' faT ~!se with a tape deck (in cluding heads) made by another. I am interested in a four-track, dual-speed system
with both recol'd and playback features. I
pl'efer the tape preamp made by Manufact~Ll'er "A," since it contains completely
separate l'ecord and playback channels, enabling monitoring of the recorded signal
while recording. Also, this preamp is available in kit form. However, I believe Manufacturer "B" makes a better tape decle, at
least from the mechanical viewpoint. The
pl'eamp has adjustable bias and eTase curl'ents, eliminating one potential problem.
However, I note from your articles on
equalization that the tape head characteristics togethel' with the pTeamp equalization circ1Lits determine the over-all systpm
l·esponse. Therefore, I foresee the possibility of a mismatch here. Is this so m1wh
of a pl'oblem as to pl'eclude the possibility
of mixing these components? Would a compal'ison of record and playback head gaps
be enough to assure a similarity of tape
heads, or are i1npedances and other factors
cl'itical?
A. The following factors are involved in
matching tape electronics to the heads so
far as recording i s concerned:
1. Proper bias current. This should be
the maximulll amount that is consistent
with preserving treble response to about
15,000 cps at 7.5 ips and to about 800010,000. cps at 3.75 ips. Insufficient bias increases distortion.
2. Prop er erase current. Curr ent should
be enough to make the head erase effectively, but not so much as to over-heat the
head, with consequent damage to the head
and/or tape (if the tape is p ermitted to
remain in prolonged stationary contact with
the head).
3. Constant audio C1trrent through the
record head at all audio frequencies, apart
from the effect of the record equalization
circuits. The rising impedance of the record
head as frequency goes up will attenuate
the high frequencies, unless the head impedance is small compared with the resistance of the tube that drives the head pIns
other circuit impedances. (For this and
other reasons, when separate r ecord and
playback heads are used, the record hend
is designed to have a low impedance) . If
the impedance of the record head is not
low at all frequencies compared with the
sum of other circuit impedances, a "constant current" resistor is introduced between the driving tube and the reeord head.
The following are considerations in playback :
1. Treble l·esponse. When playback h eads
used to have a gap of about 0.00025-in.,
there was a resulting treble loss of about
4 to 6 db at 15,000 cps at 7.5 ips. Playback
equalization was sometimes t ailored to
make up part or all of this loss. If the gap
were appreciably wider than 0.00025-in., it
was all the more likely that playback equalization included compensation for gap loss.
However, now that playback heads generally have gaps of about O.OOOI-in., treble
loss due to gap width is minimal, and playback equalization is not adjusted to compensat e for this factor. In other words, you
do not have to worry about matching the
playback head to the tape amplifier so far
as t r eble loss dne to gap width is concerned.
However, you still have to worry about
treble loss due to excessive capacitance of
the cable running from the head to the amplifier.
2. Bass response. At low frequencies the
entire playback head and not merely its gap
tends to respond to the magnetic flux emanating from the tape. This depends upon
the size and contour of the head and upon
the angle and extent of tape wrap about
the head. The effect often is to augment response at t he very low end. This in turn r educes the amount of bass playback equalization th at i s required. Thus the playback
equalization may have to be tailored to the
specific head which is employed.
All the foregoing factors ha,,~. to be
considered ill deciding whether to use the
electronics made by one m anufactur er with
the tape deck of another manufacturer.
Your decision will depend on whether you
have the means of checking bias current
and erase current, whether you are able
to ascertain that the r ecord level indicator
provides a correct indication of maximum
permissible recording level, whether you
have reason to believe that the record electronics are compatible with thE' impedance
of the r ecord head, an d whether you are
able to adjust the playback equalization,
if need be, in view of the bass char acteristics of the playback head.
"Slow Removal"
Q. It is recommended that a ae7nagneUzer be slowly removed from the heads
OT othm' m etal parts to a point three feet
away in ordel' to achieve campl·,te demag netization. I would like you to define "slow
removal" in term s of t he number of
seconds, or minutes, that sh011ld be taken
to move the demagnetizer three fe et.
A. I have no idea as to the minimum time
that will result in complete demagnetization. But I guess that if you allow 10
seconds or more for the demagnetizer to
travel the three fe et you will be on the
safe side. At least half of the time should
be spend covering the first foot. That is,
the closer the demagnetizer is to the head,
the slower it should travel.
(Continued on page 80)
AUDIO
•
NOVEMBER, 1962
PHO TO , LONDON RECO RDS
..
What brings a recording studio into your living room?
.
Ampex tape recorders are used by professional record ing studios throughout the world. And now: the Fine Line
1200 brings you an Ampex 4-track ste reo reco rder/
player. For the home. The difference in
performance sta ndard s? None . At 7~ ips,
the Fin e Line 1200 has the sa me frequency
response and low noise rating as Ampe x
professiona l models . There are three professional heads on the 1200 : one for record,
one for playback, one for erase . And there's
AUDIO
•
NOVEMBER, 1962
AMPEX Fine Line 1200.
a professional tape guidance system to keep the tape
in precise position over these heads. You'll never have
cross-ta lk. Just high fidelity sound . The Fine Line 1200
offers the finest recording and playback of
stereo so und in the home. See it at your Ampex
dea ler. It comes with the new " Four Star"
one year warranty. From the only company
providing re co rders and tape for every application: Ampex Corporation, 934 /AMIPIEX
Charter St., Redwood City, Calif. tl======::r.
I
29
A High-Quality Transistorized
Stereo Preamplifier
ERHARD ASCH INGER
Complete design and construction information about a transistorized stereo preamp designed to professional standards.
PART ONE OF THREE PARTS
been the intention of tbe
author to design and build a complete semi-p rofessional ster eo reproducing system for home use, meeting or
exceeding the high-quality standards
usually associated with professional
equipment. Naturally, the entire system
was to be fully transistorized, easily expandable, and as versatile as possible in
design.
Though the project seemed t o be a
rather difficult task in the beginning, it
was found to be surprisingly simple to
design the required high-quality audio
equipment-a certain minimum amount
of care and consideration provided.
As shown in Fig. 1 the different functions to be performed by the system have
been divided among a number of separate units (building-block technique) .
These units are constructed in rackmounted, fully interchangeable chassis
modules.
Several preamplifier-equalizer units
are provided to produce uniform signal
levels and frequency characteristics from
stereo signals delivered fr om various
sources. Equalizers for r eprodu ction
from monophonic sources are included as
well. Separate tuners are emp loyed for
T HAS LONG
I
AM and FM broadcast reception. The
"stereo control center" unit combines a
stereo SOU1'ce selector, bass and treble
tone controls, a loudness contour control,
and variable low-pass and high-pass
filters. A special unit labeled "stereo
converter" includes a phase-switching
circuit, a stereo-dimension control, and
a stereo-balance control. This unit is
followed by the master level control, the
power amplifiers and the stereo speaker
systems. While all low-level amplifiers
are powered by a common regulated
power supply, the power amplifiers have
a supply unit of their own.
For maximum versatility the lll1pedance level between amplifiers has
been set at 600 ohms per channel, unbalanced. The "standard signal level"
between ·amplifiers for the average amplitude of music program material is
245 mv across 600 obms, that is -10
dbm. The highest occurring peak values
are about 10 db above this level, corr esponding to 0 dbm.
All units of the system are f ully
transistorized. Very stringent requirements have been put on the individual
units as to frequency r esponse, distortion, inter channel balance, and noise.
STEREO CARTRIDGE
EQUI --- '
TO TUNERS
PREAMPS
{
STEREO
CONVERTE R
r-------~~------~
Fig . 1. Block diagram of complete ste reo syste m.
30
In order to obtain optimum performance characteristics, especially concerning the reproduction of pulses and transients, no transformers and chokes have
been employed in audio-frequency circuits.
The various problems arising from the
above mentioned demands could only be
solved by careful circuit design and, in
some places, by rather complex circuity. The performance characteristics
finally achieved, however, prove the effort worth while. This article will deal
with the development of the stereo phono
preamplifier and its supply voltage filter
only.
Functions of the Preamplifier
To achieve maximum fidelity of sound
reproduction the stereo cartridge employed is of the high-quality, movingmagnet type (Audio Dynamics Corporation A DC-1). Since this is a velocity
sensitive device it has a virtually flat
output voltage versus frequency characteristic (at constant stylus velocity) .
For various reasons, which shall not be
discussed in detail, a nonlinear recording velocity versus fregueucy characteristic (at constant input voltage ) is emp loyed in disc recording. To ensure flat
over-all frequency response this recording characteristic has to be compensated
for by a special unit in the reproducing
system.
Thus the stereo preamplifier has to
p erform two different functions : Fi1'st,
it has to amplify to a suitable level the
very small signal voltages delivered by
the stereo cartridge; second, it has to
provide the correct playback frequency
response to compensate fo1' the 1'ecording characteristic.
Since the RI AA recording characteristic (corresponding to DIN 45547 in
Germany) is standard in stereo disc recording, the equalizer was designed to
feature the RI AA playback curve only.
There is only one major recording com-
AUDIO
•
NOVEMBER, 1962
What can make any tape recorder sound a little more like an Ampex? AMPEX tape.
Any so und so unds thrillingly alive on Ampex recording
tape. Into each reel goes the same engineering exce llence tha t has made Ampex tape recorders the
standard by which all others are judged. It offers
greater dynamic ran ge, su peri or high frequ ency
overload characteristics. Even the packagin g
is distinctive. I n eac h box is the exc lu sive
AUDIO
•
NOVEMBER, 1962
Signature Binding to make yourtape library look as good
as it sou nds. It comes in .two types : premium-quality
Ampex 500 series and popular-priced AmpexIri sh 300 series. At yo ur tape dealer. From the
only compa ny that is providing recorders and
tape for every application: Ampex Corporation ,
934 Charter Street, Redwood City, California.
31
pany that uses its own non-standard
recording characteristic, the Deutsche
Grammophon Gesellschaft. If desired,
DGG playback equalization facilities
may be added simply by switching in two
additional circuit elements.
Performance Specifications
Each channel of the stereo preamplifier-equalizer has to meet the following
requirements :
I nput and Output Impedances. Since
the lowest permissible load resistance of
the ADC-1 stereo cartridge is 33,000
ohms per channel, the input impedance
of the preamplifier, RlJ has to be equal t o
or greater than 33,000 ohms at all frequencies. The selected output resistance,
Ro, is 600 ohms.
Signal Level. The selected standard
signal level between units for average
music program material is 245 mv into
a load resistance, R L , of 600 ohms, that
is, -10 dbm. This level corresponds to
a mean recorded velocity of 5.5 cm per
sec in stereo disc recording. The highest
signal amplitudes will be about 10 db
above standard signal level, resulting in
a maximum signal level of 0 dbm,
Thus, the preamplifier has to be capable
of delivering an output voltage, v o, of
775 mv into a load, R L , of 600 (0 dbm).
Voltage Gain. The output voltage of
the ADC-1 cartridge, at f = 1000 cps
and a stylus velocity of 5.5 cm per sec,
Vi' is 7.0 mv (per channel), the corresponding standard signal level required at the output of the preamplifier,
v o, is 245 mv.
At 1000 cps, this being the 0 db reference p oint of the desired playback curve,
the voltage gain of the preamplifier has
to be
Ig1) I =
v I 245 10v:
I = 7.0 x 10- = 35,
X
3
3
or g1)=20 log 35 =< 31 db.
Frequency Response. The frequency
response of the equalizer has to follow
the RIAA playback curve with maximum
tolerable deviations of - 3 db at frequencies below 50 cps and ± 1 db within
the rest of the frequency range. The
lower cutoff frequency of the am plifier,
f 0' has been fixed 10 cps.
Distortion. For maximum signal level
at the output (v o = 775 mv into RL = 600
ohms ; 0 dbm) the maximum permissible
1M distortion figure is 0.5 per cent.
(50 cps and 5000 cps, 4: 1); and harmonies 0.1 per cent max. at all frequencies.
Noise. The signal-to-noise ratio has to
be equal to or greater than the highest
figure obtainable with similar units employing vacuum tubes. Thus signal-tonoise ratio is 70 db minimum (referred
to standard signal level) and corresponding output noise level is - SO dbm minimum.
32
Inte1'channel Balance, Channel Separation. Since the quality of stereo reproduction largely depends upon the
two stereo channels being completely
identical, frequency response, gain, and
noise figures of the two channels have
to be balanced to within ± 1 db. Channel
separation has to be in excess of 40 db.
CIRCUIT DESIGN
The preamplifier features two comp letely identical, independent stereo
channels. All the following considerations and calculations, however, apply to
one channel only, unless otherwise sp ecified.
The required voltage gain of 31 db at
f = 1000 cps could easily be realized by
a single transistor stage. However, to
meet the additional requirements concerning frequency response, distortion,
and impedance levels, a three-stage circuit is needed. The different functions to
be performed by the equalizer have been
divided among the individual stages.
Stages one and two provide the required voltage gain and frequency response, the first stage being designed for
minimum noise. The thu'd stage delivers
the required output voltage across the
specified output impedance into an external load of 600 ohms.
To obtain high voltage gain, all stages
are operated in common-emitter connection, although transistor cutoff frequency is rather low in this configuration. High voltage-gain figures r equiJ.·e
large collector r esistors, which, in turn,
call for relatively high collector-supply
voltages. For reasons of stability as well
as for good low-frequency response all
stages are dU'ectly coupled; capacitive
coupling is employed at the input and
the output of the unit. Operating points
are stabilized against changes in transistor parameters, supply voltage, and
temperature.
An audio-frequency feedback loop
around the first two stages provides for
high stability of performance characteristics, indep endent of transistor parameter variations, low distortion,
proper impedance levels, as well as the
required voltage gain, and frequency
response. The type of feedback to be
applied depends upon the desired effect
on the input and output impedances of
the two-stage amplifier. Whereas the inp ut resistance of the first stage should
be as high as possible to avoid loading
of the stereo cartridge, the output resistance of stage two has to be made
very low to ensure linear frequency response of stage three. Both conditions
can be complied with by employing negative voltage series feedback. Since a
passive linear-feedback network, incapable of inverting phase, is to be
used, the necessary 1S0-deg. phase shift
is obtained by taking the feedback signal from the collector of stage two and
feeding it into the emitter lead of the
first stage, in series with the input signal. As will be seen later, this feedback
loop offers a very elegant and simple
way to realize the desired RIAA frequency response.
The required voltage gain at 1000 cps
being 31 db, the maximum gain is 51 db
at less than 50 cps, according to the
RIAA playback equalization. For reasons explained in detail later, the required amount of feedback at this frequency is 9 db. Thus, the necessary voltage gain of the amplifier without feedback is 60 db "at all frequencies," that
is, with a frequency response as flat as
possible over a frequency range as wide
as possible. This condition is not too
stringent since the over-all frequency
response of the equalizer will be determined mainly by the feedback network.
The required over-all voltage gain can
be divided among the three stages in
quite a number of ways. The solution
selected by the author for his own unit
is only one of them, a highly suitable
one, however. Since stage three is not included in the feedback loop, flat fre quency response and low distortion have
to be obtained by very strong local feedback. The voltage gain of this stage,
therefore, is only slightly above unity,
it is made variable within a very small
range to allow exact adjustment of overall gain of the equalizer. Stage one is
designed for low noise, its voltage gain
has to be rather high to avoid secondstage noise problems. The selected voltage gain figures are g1)l = 33 db, llvll = 23
db, g vlIl = 4 db, and gv tot = 60 db.
The exact gain figure of each stage is
obtained by applying a suitable amount
of local feedback by means of an unbypassed emitter resistor. This feedback
also provides for good frequency response and low distortion of the individual stage.
The preamplifier is powered by a
regulated power supply delivering 27
volts d.c. ± 0.5 per cent. The different collector supply voltages required by the
individual stages are obtained from a
special transistorized ripple-filter section.
SELECTION OF COMPONENTS
In the design of high-quality equipment it is mandatory to employ top quality components only, regardless of price.
However, by judicious selection of components and appropriate circuit design,
it is possible to keep the costs within
reasonable limits without sacrificing
quality.
Stereo Cartridge
The selection of a suitable stereo cartridge is of great importance if it has to
drive a transist0r input stage. Needless
to say, only high-quality cartridges
(Continued on page 37)
AUDIO
•
NOVEMBER, 1962
.
(from page 32)
a common-emitter current transfer ratio,
should be considered, having excellent Ii equal to or greater than 50.
specifications for frequency response,
Noise Considerations. Noise generated
distortion, channel separation, compli- in a transistor amplifier normally conance, and low dynamic mass. These con- sists of hum introduced by inadequate
siderations usually limit the choice to filtering of the collector supply voltage,
cartridges of the moving-magnet or mov- thermal noise generated in ohmic resisting-coil types. Since a common-emitter ances, transistor noise.
stage shows a distinct minimum of semiIn the following, hum shall be conconducter noise at a generator resistance sidered completely absent since it is
of about 800 to 1000 ohms (as illustrated rather easy to obtain a collector supply
in Fig. 2), the internal d.c. resistance of voltage sufficiently free from a.c. ripple.
the stereo cartridge should be in that
Thermal noise in resistors cannot be
order to obtain maximum signal-to-noise avoided, in our case it is insignificant,
ratio. This significant condition further however, unless extremely "noisy" resistnarrows down the choice. From the re- ors are used.
maining limited number of appropriate
At low frequencies transistor noise escartridges, the author selected the Audio sentially consists of semiconductor noise,
Dynamics Corporation ADC-1 stereo car- following the "l/f law." With low-noise
tridge as previously noted.
transistors it is a major factor only up to
The electrical specifications of the about 1000 cps. The noise figure of a
ADC-1 cartridge are (per channel) :
transistor is at its minimum in the midfrequency range where it is determined
D.c. resistance
500 ohms
by thermal noise due to the base resistInductance
400 mh
Output voltage at 1000-cps
7.0 mv at a ance and by shot noise. In the high-frequency range the noise figure is deteriStylus velocity of
5.5 cm / sec
orated by loss of gain and transit-time
Lowest permissible
effects. Since the RIAA playback curve
load resistance
33,000 ohms
requires a bass boost of 6 db per octave
To achieve optimum performance, the
from 500 cps down to 50 cps and a treble
preamplifier has been designed especially
rolloff starting at 2120 cps, semiconducfor operation in conjunction with the
tor noise becomes the only significant
ADC-1 cartridge. However, if a different
factor.
type of cartridge is used, the same conTo achieve predictable results, the
siderations und calculations can be made
maximum permissible noise figures of
using the respective new values.
first and second stage tmnsistors shall
be calculated in advance.
Transistors
All transistors employed are of pnp
germanium-alloy type units. The very
small input signal from the stereo cartridge requires the use of low-noise transistors in the first two stages, a largesignal transistor is used in the third
stage. The transistors should have a
common-emitter cutoff frequency, f ae,
equal to or greater than 15,000 cps and
First-stage noise.
The voltage gain of the entire preamplifier at 1000 cps is 31 db. According to
the RIA A playback curve the voltage
gain assumes its maximum value of 51
db at less than 50 cps. For a maximum
permissible output noise level of - 80
dbm the maximum permissible equivalent
input noise signal level, therefore, is
F= f (-I c) \
10
\
8
\
\
'\
-"
"J.
F= f(R
6
G
)
F= f (- V CE ) - _
'\
.
t thO
.
F =-!-,
viri
mpu,
. IS gIves
v NR
The thermal noise generated in the
source resistance, R a, is V1rR =4kT l!. IRa
where 1c is the Boltzmann constant,
T the absolute temperature,
Ra the source resistance, and
l!.f the noise bandwidth.
Because of the shape of the RIAA
playback curve only the frequency range
up to about 1000 cps needs to be considered.
The maximum permissible noise figure
of the input stage transistor is thus
V!Ni mlUll
FI
With
ma'" =
4kT l!. fRa
=0.213 X 10-6v
=1.380 x 10-23 w-sec;oC
VNi ma",
k
T=298°K (t=25°C)
l!.f = 1000 cps
and Ra = 500 ohms (ADC-1 cartridge)
we have
0.213 2 x 10-12
F lmlUl = 4 x 1.380 x 10 2sx298x1000x500
= 5.52 or 10 log 5.52 "'" 7.42 db.
Second-stage noise.
In order to prevent the high first-stage
'signal-to-noise ratio from being deteriorated by noise generated in the second stage the signal-to-noise ratio of
the second stage has to be higher than
that of the first stage. It has been found
that a difference of about 6 db is a suitable and safe value. The permissible
maximum ncise output level due to second-stage noise will then be - 86 db. The
maximum voltage gain of stages two and
three occurring at less than 50 cps, is 27
db the maximum permissible noise level
at 'the input of the second stage will thus
be - 113 dbm, corresponding to an input
noise voltage of 1.73 p.v.
The maximum second-stage noise figure is, therefore, given by
2
V Ni II ma",
"- "-
--/
RG = 1000 w, - vCE = 4V
'-..
-
__ - - -
4
-: -
FII ma'" = 4kTl!.fR a .
,/
- ------ ~ ....
--:_
- - - RG - 1000u, -IC= O. SmA
-V
2
-131 dbm, corresponding to an input
noise voltage, vN./ mlUll of 0.213 p.v.
The noise figure of a transistor is defined as the ratio of the total noise power
at the output of the amplifier to the noise
power which is due to the thermal noise
in the source resistant. Referred to the
CE
= 4V, - I = 0. 5mA
C
Ra is formed by the output resistance of
stage one. With Ra = Rol = 21,500 ohms
and f = 1000 cps we may write
F llma" , =
a
200
400
600
6
8
0.6
0.8
a
2
4
a
0.2
0.4
800
Fig . 2 : NO i.se chara.cteristics of the RCA 2N1 75.
}.AUD IO , .
NOVEM BER, 1962
1000 RG
- VCE
1. 0
OHMS
VOLT S
-IC mA
1.73 2 X 10-12
4 x 1.380 x 10 23 x 298 x 1000 x 21.5 X 10 3
F IImlUll = 8.46
and FII ma'" = 10 log 8.46 = 9.27 db.
(Continued on page 81)
37
ADC14. ADC-16. ADC-1B. From now on, three
names that must be reckoned with when high fidelity
lo'udspeakers are the subject.
Treble response is smooth and has very fine dispersion. The excellent response to transients gives startingly fa ithful reproduction
of the attack 'a nd decay characteristics of the various' instruments.
As with other ADC products these systems remove yet another
veil between the listener and the music.
The engineering assignment was as simple as the engineering
was difficult: "Create Audio Dynamics loudspeaker systems that
will satisfy the most finicky audio engineer, the most discriminating lover of music, the most tasteful housewife'."
Now, after years of painstaking development, Audio Dynamics
Corporation-creators of the unexcelled ADC stereophonic
phonograph cartridges-feels that its speakers have met those
criteria.
Stunning Cabinetry
The enclosure forms an integral part of the over-aU speaker design.
Peter Quay Yang, the noted designer, was commissioned to
create cabinetry to conform to ADC's strict engineering requirements and yet be attractive at the same time.
The results: shimmering walnut cabinetry that will be a point
of attraction in any horne. The ADC- f4 cabinet measures 25" x
13Y>" x 121;2'" ; the ADC-16, 27Yz" x 17" x 12Y>" ; the ADC-18,
40" x 17" x 12 112" • We know of no more handsome high fidelity
speakers than these ADC's.
The speakers are not inexpensive. The ADC-I4 retails for
$175. The ADC-I6 retails for $220 . The ADC-18, the largest ill
the group, retails for $250.
These remarkable loudspeakers are now in stock at leading
high fidelity stores. We invite you to look at them, listen to them
-and decide for yourself if what we claim is true.
Revolutionary Audio Engineering
All three of these loudspeaker systems feature a revolutionary
rectangular woofer, developed especially for ADC by the British
Engineer, Raymond Cooke of KEF Electronics.
High frequencies are handled by a unit of advanced design. A
1112" air stiffened mylar diaphragm is driven from a lYz" voice
coil. The small size of the radiating surface gives very wide dispersion, while the low mass and high flux density insure remarkable transient response.
Exceptional High Fidelity
No hyperbole could possibly do justice to the sound reproduction characteristics of these loudspeakers. Lack of cone
breakup and doppler distortion and the very low and highly
damped fundamental resonance combine to provide the "transparent," effortless, bass associated with a live performance.
38
(Ace)
AUDIO DYNAMICS CORPORATION
Pickett District Road, New Milford, Connecticut
AUDIO
•
NOVEMBER, 1962
The rigid rectangular woofer diaphragm 16" x 12" in
models ADC 16 & ADC 18 (a slightly smaller woofer is used in
the ADC 14) is molded from feather light expanded plastic and
is surfaced with aluminum. It has a radiating area twice that of
a 12" woofer, resulting in very efficient coupling to the air. The
rigidity of the diaphragm enables it to act as a perfect piston
throughout its range. There is no cone breakup. An exclusive
high compliance double surround of molded. cambric cloth is
used to terminate the outer edge. The construction giv.es positive
centering combined with the renowned damping properties of a
cloth surround. The 9 lb. ceramic magnet assembly provides a
high flux density and by careful equalization of leakage fields
extreme flux linearity is ach ieved .
Engineering Specifications
Freql,!ency Response ADC-18 . . . . ....... . . ... 20-20,000 c .p .s .
Frequency Response ADC-16 .. .... .. .. . ..... 30-20,000 c .p.s.
Frequency Response ADC-14 ..... ...... . . . . . 38-20,000 c.p.s.
BASS UNIT MAGNET STRUCTl,IRE
Flux Density
Total Flux
.'
, 12,700 Oersteds
165,000 Maxwells
TREBLE UNIT MAGNET STRUCTURE
Flux density
15,000 Oersteds
Total Flux
53,500 Maxwells
Impedance ... . . . .. ........ .. ............ . ... Due to unusually smooth
impecjifnce curve these units will operate with any amplifier imp.:edance from
to 16 ohms.
e
FRONT VIEW
AUDIO
•
SIDE VIEW
NOVEMBER, 1962
Power Requirements ..... . ..... .. . ....... ...... . ..... .. ... Due to their
relatively high efficiency these speakers will perform under
domestic listening conditions using an amplifier rated as
low as 10 watts. They may, however, be used quite . safely
with amplifiers rated up to 65 watts, R.M.S.
39
A Transistorized 200-Watt
Stereo Amplifier
72 db negative feedback around a 4-transistor d.c.-coupled output
stage reduces harmonic distortion to hundredths of 1 per cent.
RICHARD S. BURWEN "
in
transistor power amplifiers takes a
lot more negative feedback than the
usual 15 or 20 db. The two-channel
power amplifier shown in Fig. 1, 2, and
3 (developed for Lafayette Radio Electronics Corp.) incorporates 72 db of
feedback in a loop around five stages
to achieve total harmonic distortion in
the low hundredths of 1 per cent. This
extremely high feedback is made possible by the use of an all d.c.-coupled circuit to eliminate phase shift caused by
interstage transformers. The amplificr
uses a novel single-ended push-pull
class-B output stage containing four
power transistors for each channel. Each
output stage delivers 100 watts of music
power or 80 watts of continuous sinc
wave power to a 4-ohm load or 50 watts
continuous sine wave to an 8-ohm load.
Heat sink area, however, is provided
only for the intermittent duty operation
required in reproducing music.
A
CHIEVING REALLY LOW DISTORTION
Fig. 2 . Rear view of amplifier showing the plug-in circuit board.
* Consulting Electronics Engineer, 14
Scotland Road, L exington 73, Massachusetts.
Due to the elimination of coupling
capacitors and transformers the ampli-
Fig. 1. Transistorized 200-watt stereo power amplifier {Lafayette Model LA-280l.
40
fier can be overloaded occasionally without noticeable distortion. Above the overload point it clips cleanly and, since it recovers almost instantly, in contrast with
vacuum tube amplifiers, subsequent signals below the overload point pass undistorted. Because of its excellent overload characteristics the amplifier is designed with an unusually high voltage
gain of 40 db so that it can be operated
at higher average output levels.
Noise is - 90 db even with the high
gain, and the frequency response extends to 100,000 cps. The input circuit
contains two inputs: a 0.2-volt 25,000ohm input for transistor preamplifiers
and a 1.5-volt 175,OOO-ohm input for
vacuum tube preamplifiers.
One unusual feature of this amplifier
is tHat it "likes" electrostatic speaker
loads. Instead of causing oscillation, a capacitive load at the electrostatic speaker
output terminals actually makes the amplifier more stable. This high stability is
made possible by the use of an isolation
network with separate electrostatic
speaker output terminals which iso-
AUDIO
•
NOVEMBER, 1962
F' IV!
':
8,!!
~ !..!. I~ 1~1 I~
t
9_0
; : :. f... :. :. :. " :.
__
... ,.• -
Kl" I~
.. ~:
IM •. S. ~ ••~ .~ . _~ '.,~ .. ~ • ~. ,
1M
I
SO
ii
~
96
~
100 101
IV!
=
'. ~n~~
;!O
F' IV!
~
8,!!
;
9J
9..0
~
:.
.!LJ!.
~
:.
:.
.~
I~ ~ I
:.:.
1~6 I~
:.":
IV!
=
'''ST!O~
.;19 . .
I~ 106 IDS
Hear here.
Hear the astonishing new sound . . .
the clean, rich, surrounding sound .. .
the pure, simple, ear-catching sound
... of PILOT. Hear it reproduced with
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Hear your favorite music with the
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which includes PILOT'S unique Multiplex circuit (better than 30 db separation); automatic FM Stereo indicator; record changer, turntable, tape
transport and recorder connections;
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with added AM, is just 299.50.)
Hear your music favorites with the
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(top-rated by HIFI/ STEREO REVIEW),
including FM Multiplex, automatic
FM Stereo indicator light and 14 controIs ... for only 329.50 with cover.
Hear your favorite broadcasts with
the 285 FM Multiplex-AM Tuner,
only 159.50 ... combined with the 50watt 246 Integrated Stereo Amplifier,
top-rated by an independent consumers' laboratory-with 12 stereo
inputs and 14 controls, 199.50.
Whichever PILOT component you
happen to select, you're assured of
a quality instrument that is secondto-none. And you're also assured of
incomparable sound enjoyment that
must be heard to be believed. Where?
At your PILOT dealer, of course.
PILOT offers you a wide range of
stereophonic components as well as
a variety of three-way speaker systems. For complete literature, write:
PILOT RADIO CORPORATION, 37- 44 36TH STREET, LONG ISLAND CITY 1, N. Y.
AUDIO
•
NOVEMBER, 1962
41
A
larger than the positive half cycle. The
distortion due to this waveshape looks
like a full-wave rectified sine wave having a peak-to-peak value of only 0.012
per cent. The predominating second harmonic component, as derived from a
Fourier analysis, is only 0.0053 per cent.
In practice the feedback does not increase to infinity during the negative half
cycle, but only to about 96 db.
Using this type of output stage causes
the error signal inside the amplifier to
be practically a half-wave rectified sine
wave to produce a sinusoidal output.
Yet the output distortion is very minute.
When measuring the error signal, an
ordinary a.c. vacuum tube voltmeter indicates about half the value it would on
a full sine wave. The computed average
feedback factor from error- and inputsignal measurements is therefore 6 db
higher than its value of 66 db during
the positive half cycle, or 72 db. It can
be seen from this computation that it
is the amount of feedback occurring during the low-gain half cycle that really
counts in reducing distortion.
Why start out with such high distortion when there are a number of more
symmetrical circuits that can be used Y
Of numerous circuits tested this type
of output stage produced gain and phase
sbift characteristics that made possible
the greatest amount of stable feedback
during the low-gain half cycle. The advantage appears especially at the edge
of overload where nearly all driver and
output combinations have drastically increased high-frequency phase lag which
tends to cause oscillation.
The complete power stage, Fig. 4, uses
four power transistors per channel to
provide nearly twice as much output
voltage and power as the circuit shown
in Fig. 5. In the complete stage the common-emitter power transistor, Qs, drives
an identical transistor, Q6J thr ough its
emitter. The base voltage of Q6 is fixed
by means of resistive divider Rw R~.J
and Ru which divides the total voltage
equally between Q5 and Q6 at maximum
negative swing. Since Q~ is driven more
or less as a common-base amplifier, its
collector current is very close t o that of
Q5' Thus the combination of Q5 and Q6
is able to drive twice the load impedance
that could be driven by Q5 alone.
During negative half cycle, the collector signal from Q6 drives Qr as an
emitter follower through stabistor CR!
in the same manner in which QA directly
.> _ _ _
Fig . 3. Botto m view of chassis.
is many times the gain during the positive half cycle. When QA drives the output positive it "sees" a load R L , and the
current gain from the base of QA to the
output is that of transistor QA' During
the negative half cycle transistor QA
conducts current only through RA and
drives transistor QB as an emitter follower. Therefore the current gain during
the negative half cycle is nearly that of
Output Stage
Q'A and QB multiplied. The output then
Since the output stage, Fig. 4, is d.c.- looks something like a negative-going
coupled to the speaker, it requires sepa- half-wave rectified sine wave. What
rate + 35-volt and - 35-volt unregulated makes this open-loop distortion tolerable
power supplies. Each supply has a pair is the tremendous amount of negative
of 25-amp silicon rectifiers feeding a feedback.
To see thc effect on the over-all per5000-pI output capacitor. Hum and
modulation caused by these supplies are formance, the closed loop distortion can
eliminated by the extremely large nega- be easily computed using the basic
equation for gain, G, with feedback in
tive feedback.
Figure 5 shows a simplified schematic terms of the open-loop gain, A, and
of the output stage in which transistors the feedback factor ~:
Q6 and Q6 in the left ·channel are rcA
placed by a single transistor QA, and
G = l-A~
transistors Qr and Qa are replaced by
During the positive half cycle the open
QB' The drive signal appears between the
loop gain is 200,000, or 106 db, and 1
base and emitter of QA' When QA conducts heavily it effectively connects the is 0.01 corresponding to a 40-db closedload through CR 4 across the + 35-volt loop gain. Then the closed-loop gain is
supply, thereby delivering a positive out- within 0.05 per cent of being exactly
100 or 40 db. Even if the open-loop gain
put approaching + 35 volts. When QA is
increased to infinity during the negative
driven towards cutoff, rectifier CR 4 dishalf cycle, the maximum change in
connects its collector from the load RL
closed-loop gain, G, would be 0.05 per
and allows the current through RA to
cent since the gain approaches exactly
"turn on" transistor QB' When QB con- 100 as A increases to infinity. Thus
ducts heavily, the output across RL ap- with 66-db of feedback the negative
proaches - 35 volts and none of the load half cycle is a maximum of 0.05 per cent
current goes through QA' This output
circuit is not symmetrical, but it has the
FRE Q UENC Y
LEFT CHANNEL
advantage that it does not require smallPOWER (WATTS)
HARMONICS(%)
'P'
signal driver transistors to handle the
15
64 , 8
O. OISO
::Eo
Table
I
Summary
70-volt peak-to-peak swing. It is almost
100
90,0
I«
0 . 0 130
00
1000
81,0
0,0 11 0
impossible to burn out a driver transistor of di stortio n me as~~
10,000
39, 0
0 . 3500
due to an overload on the @utput stage. ure ments.
15
45
.
0
0,
0095
::Eo
Sine-wave distortion in this type of
100
J: «
48,0
0,0070
00
1000
49,0
circuit is obviously very high because
0.0070
10, 000
40,0
0,0 11 0
the gain during the negative half cycle
lates the load capacitance from the main
feedback loop. Any value of load capacitance can be connected across these
terminals without causing appreciable
ringing.
The amplifier is ruggedly constructed
and the main etched circuit board
mounted vertically on top of the chassis
plugs in for easy maintenance.
RIGHT CHANNE L
POWER (WA TTS)
.;, ~
42
AUDIO
•
HARMO NIC S(%)
64,0
90, 0
85,0
45,0
0 . 220
46,0
46 . 0
48 . 0
40,0
0,0 16
0, 011
0,007
0 . 095
0,050
0,042
0 , 044
NOVEMBER, 1962
It took 300 years to make Athanasius Kircher's dream come true.
Athanasius Kircher was a man of vision. Among his many
accomplishments, this 17th Century scholar perfected the
Aeolian Harp and invented a Tin Pan Alley dream-a compos·
ing machine. But his outstanding achievement . .. the Kircher
Broadcasting System shown above, actually called for out·
sized cornucopias of sound built into walls. This system pio'
neered principles in use today.
The boldness, the vision of such a man, is truly epitomized
today in the remarkable new instruments tor high fidelity de·
veloped by University. In University's modern sound labora·
tories (what a treat they would be for Kircher) engineers de·
voted to the perfection of sound reproduction are creating
extraordinary musical instruments. Consider the Classic Mark
II. In according it top·notch rating, Julian Hirsch of Hirsch
Houck Laboratories wrote: "In listening tests, it sounded very
clean ... there was an undercurrent of bass more often felt
than heard that was completely lacking in some other quite
good speaker systems that I compared to the Classic Mark II.
Overall·, the sound was beautifully balanced ." The low frequencies up to 150 cps are handled through a 15-inch high
compliance woofer in the tuned ducted port. An 8-inch midrange speaker covers from 150 to 3 ,000 cps, and above this,
the superb Sphericon Super Tweeter takes over. Impeccable
cabinetry, in oiled walnut. 35"w x 28 1,4"h x 17"d. $295. Hear
it at your hi-fi dealer's or write for complete specifications and
free Guide to Stereo High Fidelity_ University loudspeakers,
Desk R-l l A, 80 South Kensico Ave., White Plains, New York.
111
Ul'I.O
~
A Divisi on 0 1 L1ng -Te mc o-Vought. Inc
The Classic Mark
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02 , 03,0 10, O il , PTI4 51
04 , 012, TI487
05 , 06,07 , 08 , 0 13, 0 14, 015 , 0;6,2NI982
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A distinguished audio engineer, commenting on the
new University bookshelf systems, has described them
as speakers that were "listened into being." A perceptive remark. It characterizes all University speakers,
but has special relevance for our new compact systems.
Bookshelf systems are naturally attractive where
space is at a premium. Unfortunately, many of them
use built-in compromises to imitate the robust quality
of their big brothers. The result has often been a false,
boomy bass, coupled with unnatural highs. The sound
is flashy but it soon fatigues the ear.
University engineers knew what to avoid in designing the Senior II and Companion II. It was not enough
to create speakers that performed well on test instruments. They had to have the University sound ... a
natural, musical sound ... sound that was "listened into
being." Repeatedly, they were listened to and refined
by engineers who combine technical knowledge with a
profound understanding of music. You can hear the
result for yourself-reproduction entirely free of coloration or exaggerated effects.
Un ive r si t y En gi nee rs: (I t o r. ) Victor Broein e r, Oir. of En g in ee rin g , John King , Ea rl Matsuo ka
Th e Senior II and Companion II feature the exclusive Univer·
sity RRL tuned due ted port enclosure which provides maximum
output and undistorted bass with moderate· powered amplifiers.
The S enior II (shown) has a 12" woofer, 3~" mid·range and
Sphericon Super Tweeter. Frequency response: 30·22,000 cps.
Size: 25" x 15%" x 12%" deep. Oiled Walnut finish-$99.50 .
Companion II-10" woofer, 3" midrange and new diaphragm-type
tweeter. 35·18,000 cps. 24" x 13~" x
~
11 ~" deep. Oiled Walnut-$79 .50. ~
Writ e for fre e catalog. UNIVERSITY
LOUDSPEAKERS, Desk No. R -II, 80
So. K ensico Ave., White Plains, N .Y . A O;v;s;o n of Lin g· T emeo·Vo ught. Inc
l+t+t+1
jJNIVfRSIT!.
r---_>--------~
_________- - - - - - - - - 1
-35 v
+35 v
Fig. 5. Simplified representation of output stage.
drives QB in Fig. 5. Rectifier CR. performs the same function as in Fig. 5,
disconnecting the collector of Q6 from
the load during negative outputs. Qs is
an emitter follower which swings the
collector of Q7 so as to divide the total
voltage at maximum positive swing
equally between Q7 and Qs' Its base
input voltage is determined by the divider R£7) R u ) and R£9' Capacitor C 15 is
used to bootstrap the drive signals for
both Q7 and Qs so as to provide enough
current drive at full negative output to
saturate Q7 and Qs. Similarly C 12 increases the current drive to a value sufficient to saturate Q6 at full positive output.
In spite of the high open-loop nonlinearity previously discussed, it is still
necessary to minimize crossover distortion. Otherwise the closed-loop distortion will increase with small signals and
this is very undesirable. There must be
no region where neither Q6 nor Qs are
contributing to the output.
Normally the no-signal collector current through Qsand Q6 is 450 mao This
current flows almost entirely through
CRs and the divider R£7) R 2s ) and R. 9.
Similarly, at no signal, Q7 and Qs conduct 450 ma through R u ) R 2 .) and R H •
Thus, at no signal, all four transistors
are biased into a region of high gain.
Crossover distortion then is determined
by the ClllTent through CR. at no signal
since this rectifier conducts only when
the output is driven positive. The nosignal current through CR. is determined by the voltage drop across it which
in turn is determined by the voltage
across CRs less the base-to-emitter drop
of Q7 less about 5 mv dropped across
R 66 . The actual 0.5 volts across CR. at
no signal produces a current of about
20 ma, an amount sufficient to reduce
the crossover distortion to a tolerable
level.
Since the current through a rectifier
of this type increases about 9 times for
46
every mv increase in forward voltage, it
tends to increase greatly with temperature due to the - 2.5-mv per degree
Centigrade temperature coefficient of the
base-to-emitter diode in Q7' In addition
there is a similar temperature coefficient
in CR.) but this is compensated by the
temperature coefficient of CR s. The current is prevented from increasing too
much at high junction temperatures by
emitter degeneration across a 0.24-ohm
resistor, Ru.
Temperature stability of the power
stage is maintained not only by this
emitter degeneration, but also by the
main feedback loop. Unity d.c. feedback
from the output to the input causes the
~verage output voltage to remain at zero,
mdependent of ill'ifts in the output
stage and other stages of the amplifier.
The output circuit as described so far
works well at low frequencies, but gets
into trouble at high frequencies due to
the slow recovery time of rectifier CR:,.
As the output swings from positive to
negative a transition must occur where
Qs and Q6 conduct very lightly, while
Q7 and Qs begin to conduct. Q7 cannot
conduct unless it becomes forward biased
by the current through R !7' Since CR I
acts as a very large capacitance it takes
time for the forward conduction voltage
across CR. to decrease far enough to
allow some of the current through CR s
to be diverted into the base of Q7.
With the square wave input, the output switches from negative to zero and
then remains constant until CR. discharges, at which time Q7 and Qs can
start conducting, driving the output
positive. This momentary step in the
output lasts for 10 to 20 '!los and produces
very poor results at high frequencies.
To remedy this charge-storage problem,
a 22 ph choke, L . ) was added in parallel
with resistor R so. During the time when
Q5 and Q6 conduct, L" stores enough
energy to drive the base of Q7 negative
causing Q7 and Qs to conduct rapidly.
L. is released by the cutoff of Qs and Q6'
This choke increases the power bandwidth of the amplifier by more than 3
to 1.
When using audio power transistors
the only way to ' achieve full output
above the ~-cutoff frequency, typically
4000 cps, is to provide added drive i~
both the turn-on and cut-off directions
over that needed at low frequencies. It is
the maximum rate of swing available
that limits the high-frequency power
output. To aid in turning on Q5 quickly
high base current is supplied by a 15~
watt silicon driver transistor, Q•. Its current capability is increased above 10,000
cps by capacitor C9 connected across the
collector-dissipation-limiting res is tor
R 17 • Transistor Q" can conduct up to 0.7
amperes peak at high frequencies.
Since Q. can only turn on Qs) substantial back-bias current must be sup-
plied to cut off Qs quickly. During the
time Q. and Q5 are conducting, energy
is stored in r.f. choke L2 and, when Q.
cuts off, the discharge of energy from L!
helps to cut off Q5' The choke provides
greater turn-off current than would be
available if only the 10-ohm resistive
component of L . in parallel with resistor R16 were used to back-bias Q5' Backbias voltage is provided by the I-volt
drop across stabistor CR! due to the
emitter current of Qs·
Due to the heavy turn-on current
available for QS) the output can swing
from full negative to full positive in
about 12 !-ts, whereas a swing from full
positive output to full negative can take
as long as 30 J.Ls even with the help of L .
and L". When there is no load connected,
the output can swing very much faster
in the positive direction than in the
negative direction. An overshoot due.to
phase shift in the feedback loop can
therefore be rapidly corrected if the
overshoot is negative, but only can be
corrected slowly if the overshoot is positive. This effect tends to produce a positive spike in the output, immediately
upon recovery from an overload in the
negative direction, when there is a highimpedance load. To reduce the amplitude
of this spike a nonlinear network, L 9 )
R 6,,) R 65 ) CR l s) and C S7) was added. The
network provides negative feedback
from the output to the base of Q5 in
proportion to the rate of swing in the
positive direction, thus limiting the drive
to Q5' Because of rectifier CRw the network has practically no effect when the
output swings in the negative direction .
This network therefore tends to equalize
the rise and fall times of the output
circuit.
The transistors used in the output
stage are hefty germanium alloy junC'tion types (Tung-Sol 2N1982) having a
maximum thermal resistance of 0.5-deg
MICROSWITCH
+
=
o
=
300 v
42 v
CRO
.---+---:-::":--+0 v
H
GND.
1 50 ~f
100w
+5%
12 1C
~# ~
..-- ::, \ INCLUD ING CO il
RES ISTANCE
C! 'I
Fig. 6. Test circuit for determining safe
operating area of power transistors.
AUDIO
•
NOVEMBER, r962
The- woird's smallest watch, $3000 - "courtesy of Vacheron & ConstantiO-LeCoultre Wat~hes, Inc.
Swiss precision
MODEL TD-124 TRANSCRIPTION TURNTABLE
CRAFTSMANSHIP - unique in its precision - superlative in its design and style with more built in versatility,
more conveniences and features than any other Turntable
available today - on these the THORENS TD-124 has
built its reputation.
As with the SWISS watchmakers renowned throughout
the world for their precision made parts, some almost
microscopic in size, all to microscopic tolerances. Noone
surpasses the SWISS in precision manufacturing.
No one has surpassed the precision crafted THORENS
Turntables either, A mere glance beneath the table tells
you why; machined parts, precision balanced, polished to
mirrorlike finishes - no mere metal stampings these! The
drive system offers you the finest features of belt plus idler
drive, plus a 10 pound table, machine balanced - no holes
or slugs are ever used to balance this table!
We invite you to visit a franchised dealer. See the TD-124
and all the family of fine Thorens Turntables .... then
make a one minute comparison test with any other turntable (that's all you'll need) or write us direct.
. Guaranteed for One Full Year.
Thorens TD-121 - $85 net
_ .. an unexcelled Swissprecision Thorens for those
requiring 33% rpm only
(convertible to other
speeds ). There's a Thoren s
model to fit every purse
and turntable application.
THORENS TO-124 - $110 net
BASES from $10 to $35
THORENS DIVISION
ELPA MARKETING INDUSTRIES, Inc.
New Hyde Park, N. Y.
In Canada: T1'i-Tel Associates Ltd., Willowdale, Onto
AUDIO
•
NOVEMBER, 1962
47
IT
4 01M
I
JolD II III
.........
/'
...... I:::
1
---
-2
-3
:g
4 OHM LOAD - 2 CHANNEL S...........
8 OHi LCn
~+-
80 WA TT S
80
~I~
~
.~
-4
-5
o db
16 OHM LOAD
\\
6
20
\\
7
'i
8
9
-I 0
10
2
J
4 5
8
10
100
I~
10,000
5
100.000
FREOUENCY IN CYC LES PER SECOND
Fig . 7. Ma xim um powe r ou tpu t vers us load impeda nce and freque ncy.
Centigrade per watt from junction to
case. The type and size of transistor required is determined not so much by the
requirement to deliver sinewave power
to a resistive load, but by the requirement to handle extremely high energy
pulses when delivering square waves to
an inductive load. Consider what happens when the amplifier is required to
deliver a step in output from full negative to full positive swing to a 4-ohm
speaker system. Such a condition might
occur when switching inputs in a preamplifier control unit or when tuning in
an FM station.
Assume the speaker system is fairly
efficient and has a bass resonant frequency of 60 cps. At low frequencies the
electrical equivalent circuit is the d.c.
resistance of the voice coil, typically 3
ohms, in series with a parallel resonant
circuit tuned to 60 cps. At very low frequencies the inductive component of the
resonant circuit is most significant anti
might amount to 22 mho J ust before
switching, the amplifier could be delivering - 30 volts at -10 amperes to the
voice coil. Right after switching the
inductive component of the load tends to
keep the current in the same direction
while the output is now + 30 volts. Since
the current is in the wrong direction, it
is not transistors Qs and Q6 that conduct
but rather transistors Q7 and Qa} which
have about 65 volts across them at this
moment. Thus the combination of Qr
and Qa is momentarily required to dissipate 650 watts!
The total energy dissipated in the
transistors is that due to the first half
of an exponential change in current
from - 10 amps to + 10 amps, in other
words that due to the change from - 10
amperes to zero. The voltage during this
interval is a constant 65 volts. Since the
time constant LIR is 7.3 milliseconds,
there will be an average current of
slightly less than 5 amperes for 5.1 milliseconds producing a total energy of 1.6
watt-seconds. When the damping and capacitative components of the speaker
impedance are taken into account, the
48
energy fed back to the transistors is reduced somewhat, but 1.6 watt-seconds
represents a good value for design purposes. Variations in the current gains of
transistors Qr and Q8} and toler ances in
the divider R 2 rJ R f8 } and R 2 9 may cause
a somewhat unequal distribution of this
power between Qr and Q8' Either of
these transistors might be required to
dissipate as much as 430 watts p eak with
a total energy of 1.1 watt-seconds. This
tremendous amount of power requires
the use of the largest available junctions
with appropriately large thermal capacity so that they can absorb this energy
without burning out.
Low-thermal-capacity transistors such
as the new high-frequency diffused germanium types will burn out instantly
under such conditions. The diffused-base
germanium transistors made by several
manufacturers were tried first before resorting to low-cutoff-frequency audio
types. It was found that the diffusedbase transistors would go into thermal
runaway or secondary breakdown at
steady-state dissipation levels well below
their dissipation ratings when the collector-to-emitter voltage was over 30
volts. This indicated that these transistors were suitable only for relatively low
power amplifiers and could not be used
for anything like 100 watts per channel.
To assure the ability of every transistor to handle the 430-watt surges of
power possible in this amplifier, a safeoperating-area test should be conducted.
The test setup is shown in F i g. 6. In this
test a capacitor-discharge sweeps the
collector current exponentially from 10
amperes to zero while maintaining a
constant collector-to-base voltage of 42
volts. The energy discharged into the
transistor is 1.6 watt-seconds, or about
1.5 times the maximum that can occur
when used in the amplifier. A transistor
passes the test if its curve of base cur rent versus collector current, as observed
on the oscilloscope, is continuously negutive, indicating the externally supplied
turn-on base current always has control.
Transistors f ailing the test frequently go
into secondary breakdown and are destroyed.
Operation with a 4-ohm load requires
transistors with a d.c.-current gain of 35
at 10 amperes. Low-gain transistors have
the effect of causing clipping at lower
power output levels. With the transistors used, full output voltage can be delivered to a 3-ohm load, a value which
can occur at some frequencies using a
speaker system rated at 4 ohms.
Feedback System
Since the amount of stable negative
feedback that can be placed around the
output stage at high frequencies increases with the gain bandwidth of the
loop, r .f. transistors are used in all the
early stages. Transistor QJ is a germanium pnp co=on-emitter stage d.c.
coupled to the base of Q2' Diode OR}
in the base circuit of Ql helps maintain
sy=etrical clipping during severe overloads by equalizing the positive and
negative currents that flow through the
emitter bypass capacitor, G111 • Transistor Q! is a common-emitter stage using
a small silicon npn planar unit having a
gain bandwidth of over 50 megacycles.
This stage is d.c. coupled to an emitter
follower, Q3 } which uses the same type
transistor. The driver transistor, Q4} another co=on-emitter stage, uses a 15watt, 15-megacycle gain-bandwidth silicon unit.
Feedback from the main speaker output terminal goes all the way back t o
the emitter of Ql ' Without feedback, an
input signal of only 50 IJ.l.V at input J !
will produce full output. With feedback
the voltage gain is reduced to 100, or
40 db, requiring an input voltage of 0.2
volts rms for a 20-volt output.
Stabilization of the feedback at low
frequencies was no problem since the
circuit is d.c. coupled. The emitter-bypass capacitor, 01 11} allows 100 per cent
feedback at d.c. from the output to the
emitter of Ql ' Thus at d.c. the amplifier
behaves as a five-stage emitter follower
which has unity voltage gain and very
high d.c. stability. The initial d.c. offset
is only 0.3 volts out of a peak output
of 28 volts and it does not change significantly with signal. Variations in d.c.
offset with signal, which limit the power
output under transient conditions, have
been one of the chief causes of muddy
quality in some transistor amplifiers designed in the past.
Stabilizing the feedback at high frequencies proved to be extremely difficult. The basic philosophy was to achieve
the maximum possible feedback at frequencies up to 20,000 cps in order to
attenuate adequately the second .harmonic of a 10-000-cps signal. Distortion
components above audibility are unimportant as long as no audio-frequency
intermodulation components are associated with them. In order to provide all
AUDIO
•
NOVEMBER, 1962
INC.
rofessional
workhorses
.-..~----
These AR-2a speakers have been serving as portable monitors for recording sessions since 1959. They have been shipped, carried in taxis,
and stowed in car trunks. They have worked in studios, in concert halls,
and; propped up on logs, in the Kentucky woods. They have presided over
the recordings of a variety of artists - pianist Ann Schein, bandleader
Eddie Condon, folk singer Theodore Bike!.
David Jones, the recording engineer who owns them, brought them in to
AR for a preventive maintenance checkup. We made a few minor repairs,
replaced the grille cloths, and took a picture of them.
AR loudspeakers are often used in professional applications because of
their natural musical quality, but they are primarily designed for use in
the home. AR-2a's are $109 to $128, depending on finish; other models
are priced from $89 to $225. A five-year guarantee covers the full cost
of any repairs, including reimbursement of freight charges.
A catalog and list of AR dealers in your area are available on request.
ACOUSTIC RESEARCH, INC.,
AUDIO
•
NOVEMBER, 1962
24 Thorndik e
St., Cambri dge
41, Mas ~ .
49
DISTORTION
METER OR
A.C. VTVM
r;::,:::
~---,
I~I
VE RT.
r;::
I r
I
II
II
r
of L 2 and L", produce an amplifier that
is free from oscillations and ringing.
o
HORI Z .
eRO
II
II
r;::-JL-----~J
,---------
A. C. VTVM
RL
3
LOW-DISTORTION
OSCILLATOR
g
L _____ _
J
Fig. 8. Circuit for measuring distortion levels below the range of available instrumentation in a non-inverting amplifier with a voltage gain of 40 db.
this feedback with the limitation of
audio transistors in the final stage it was
advantageous to design a conditionally
stable feedback loop. This means the
phase shift around the loop can exceeu
180 deg. in the vicinity of 70,000 cps
while it is reduced to about 120 deg. in
the region where the feedback becomes
unity at 1.5 megacycles. The high phase
shift at 70,000 cps occurs when the load
is disconnected and the amplifier is
driven to the edge of overload. When a
load is connected the phase shift is
reduced.
To achieve the desired open-loop response curve, and at the same time handle wide variations in the load impedance including a pure resistive load, It
pure capacitive load and an open circuit, it was necessary to minimize the
variations in frequency and phase response caused by 'changing the load.
This was accomplished first by isolating
capacitive loads from the output by
means of a network R s1 , La, and RS2 and
providing a separate electrostatic speaker
output from terminal 1 to ground terminal 2. Thus when a capacitive load is used
the minimum load impedance the amplifier sees above 150,000 cps is 10 ohms
due to Rw in parallel with any resistance that happens to be connected between main speaker terminal 3 and
ground.
The effect of variations in the load
capacitance at the electrostatic speakcr
terminals was minimized by connecting
a dummy load of 0.33 ~f across this output at all times. With this isolation network variations in load impedance above
150,000 cps are held to about 3 to 1
and no additional phase shift is caused
by adding a capacitive load at the electrostatic speaker terminals. In fact connecting a capacitive load actually reduces the phase lag above the resonant
frequency of the isolation network and
helps the stability.
Stabilization of the 66 to 96 db of
feedback that occurs respectively during
50
positive and negative outputs basically
required increasing the phase shift and
rate of rolloff between 20,000 cps and
100,000 cps and decreasing both between
100,000 cps and 3 mc. Phase lead between 100,000 cps and 3 mc is provided
by 01J which shunts the feedback resistors, R 19 and R 2o • Capacitor OlO was
added to form a bridged-T network so
as to provide fiat closed-loop frequency
response out to 100,000 cps.
The high frequencies are rolled off internally by means of local high-frequency feedback from the emitter of Q"
through capacitor Os to the emitter of
Ql' The feedback voltage is developed
across an r.f. choke, Lv in series with
the emitter of Q". Capacitors 0 14 and
016 in the output stage also aid the stability of the main feedback loop. At
high frequencies they maintain a constant collector-to-base voltage across
their respective transistors making the
transistors behave like zener diodes. In
the case of Q., 0 14 eliminates the phase
shift which would otherwise occur at
extremely high frequencies between the
collector of Q5 and the collector of Q6 '
All of these stabilizing networks in addition to the previously mentioned effects
+0.
Performance
The developmental model was built
with a set of high-gain power transistors
in the left channel and a set of low-gain
units in the right channel in or der to
compare the effect of transistor variations on the distortion and power output. With a 4-ohm load the low-gain
units had about 3 times as much lowfrequency distortion because they could
just barely be driven into saturation
(less than 1 volt collector-to-emitter
drop), whereas the high-gain units could
be driven into saturation even with a
3-ohm load. Using an 8-ohm or higher
load impedance, the low-gain transistors
easily delivered the full available voltage and their distortion was similar to
the distortion produced by the high gain
units. Table 1 is a summary of the distortion measured with each channel operating alone. (see page 42).
The final amplifier uses selected highgain 2N1982 transistors to achieve the
low-distortion level of the left channel.
The reason the distortion figures above
are higher than the low-frequency theoretical maximum of 0.0053 per cent
peak-to-peak, arrived at earlier for :t
4-ohm load, is that the calculation did
not take into account the reduction in
feedback that occurs at high collector
currents as the collector voltage approaches saturation. Also there is some
second harmonic distortion due to Q I
because the base and emitter are both
swinging 0.2 volts rms and the collector
current does not quite remain constant.
The measurements above were made
at output levels in the low-distortion
region below clipping. When the maxi··
mum power output at various frequencies and load resistances is considered
in terms of the usual per cent total harmonic distortion, the output is higher liS
shown in Fig. 7. Since the power supplies are quite stiff, and the amplifier
can deliver over 0.9 of the available
db
...-
1--11--1I
2
-3
2
3
45
B
10
5
5
5
100
l~
FREQUENCY IN CYC LE S PER SECO ND
10,000
100.000
Fig. 9. Frequency response of left channel with an imput of 0.1 volt and a load of
" ohms.
AUDIO
•
NOVEMBER, 1962
an accurate timepiece
A clock or watch is undoubtedly more convenient for telling
time. Yet, it is actually possible to keep accurate track of time
with a hysteresis motor-driven Miracord turntable.
The speed of a hysteresis-synchronous motor is precisely regulated and timed by the frequency of the line current. This
speed is constant even with variations in line voltage and load.
.,
You can see this flywheel effect with the turntable platter
removed. After starting the motor by lifting the arm from its
rest, you let it run for about 10 seconds. You then shut the
power off, by replacing the arm. The rotor will continue to
spin by the sheer momentum of its own mass for at least
20 to ,30 seconds. Most motors will stop in about 3 seconds.
The Miracord is the only record playing instru·
ment with hysteresis motor, dynamically bal·
anced turntable an!:1 ma,ss-balanced transcrip·
tion arm which you can play manually, or as
automatically as you please. The Miracord is
also available with 4-pole " induction motorthe Model 10, priced at $79.95. The Miracord
10H with hysteresis motor is $99.50. Prices
include arm, but are less cartridge and base.
Consequently, a hysteresis motor-driven turntable will rotate at the precise record speed, and
maintain that speed regardless of voltage fluctu·
ation, or the number of records on the platter.
The Miracord 10H uses the famous Papst hys·
teresis motor with the outside rotor. It's the
same motor employed by the finest professional
turntables and tape transports. The external
rotor is a dynamically balanced mass. As it
spins, it acts as a flywheel, further smoothing
and evening out the motion of the turntable.
·
MIRACORD
Make it a point to see the Miracord at your
high fidelity dealer soon. for details, write to:
BENJAMIN ELECTRONIC SOUND. INC . 80 SWALM STREET. WESTBURY. NEW YORK. SOLE U. S. DISTRIBUTOR FOR ELECTROACUSTlC® RECORD PLAYING COMPONENTS
AUDIO
•
NOVEMBER, 1962
51
supply voltage to the load, the power level occurs in the vicinity of 162 watts
output capability of the amplifier is total power output with 4-ohm loads.
nearly that of a constant-voltage gen- There is no clipping of the high freerator. Its power output increases as the quencies at low levels due to the highload impedance decreases. At 100 cps frequency power limitation. The music
the maximum output from either chan- power output is no higher than the sine
nel measured with a 115-volt 60-cps line wave power output largely because the
i:; 91 watts into 4 ohms, 58 watts into 8
power-supply voltage drops about as
much with musical signals as with sine
ohms, and 31 watts into 16 ohms.
A 10 per cent drop in the power sup- wave signals. However, by the IHFM
ply voltages is the main reason why the industry standard of measurement using
power delivered to a 4-ohm load is only unvarying supply voltages the amplifier
3 times that delivered to a 16-ohm load produces over 200 watts of music power.
instead of 4 times. When both channels Unless the power supply filter capacitor
operate simultaneously with 4-ohm loads is much larger than is economically althere is a further drop of 10 per cent lowable in most amplifiers, the voltage
in the supply voltages which limits the will drop quickly whenever the program
output to 81 watts per channel or 162 material has heavy bass content. Therewatts (continuous sinewave) total. Fig- fore, excepting the unlikelihood that the
ure 7 includes a curve of output versus program material has practically no
frequency for the left channel when both bass, the musical output is linlited by
channels are operating.
It will be noted that the power output
falls off drastically above 15,000 cps
particularly with a 4-ohm load. This is
due to the previously explained limitation in the switching time of the audio
transistors used in the output stage.
They simply cannot be made to swing
any faster without wasting a lot more
power to increase the drive current.
Since the no-signal power input is al- '
ready 70 watts per channel, equally divided between the transistors and their Fig. 10. Squarewave output at 10,000 cps.
base resistors, that is the limit.
The reduction in power output above the sinusoidal power handling capabil15,000 cps in no way detracts from the ity rather than the peak power.
The distortion in this amplifier is
performance with musical signals. Certain types of program material, such as lower than the capabilities of commerscraping noises, have substantial energy cially available distortion analyzers,
content above 15,000 cps. However, therefore, it was necessary to devise a
practically all the material available special test circuit to extend the range
today, on either tapes or records, has a of the conventional measuring equipmaximum output at 20,000 cps which is ment. The test circuit shown in Fig. 8
down at least 14 db from the mid-range was designed especially for this amplilevel. This reduced energy content at fier and uses a signal cancellation techhigh frequencies results from the nat- nique. The vacuum tube voltmeter or
ural limitations of the musical instru- distortion analyzer shown is connected
ments, the microphone, and studio to measure the distortion and noise comacoustics. Also, the pre-emphasis used ponents remaining after subtracting onein recording limits the levels which can half the amplifier output voltage from
be inscribed on the record grooves or the fifty times its input voltage. With an
tape. Thus it is sufficient if an 80-watt amplifier having a voltage gain of 100
amplifier can deliver 3 watts at 20,000 the fundamental and any harmonics
cps. Examples of program material re- from the audio oscillator are completely
quiring more power output at 20,000 cancelled out provided the signals which
cps can be found, but are very rare. In are subtracted from one another are
any case the material can be reproduced subjected to the same gain and phase
without distortion at reduced levels. shift. Distortion and noise generated in
Where the power is really needed is at the amplifier are not cancelled out, but
the extremely low end of the spectrum read on the meter. The circuit includes
where the speaker system is inefficient, adjustments for gain, low-frequency
and this inefficiency is frequently com- phase, and high-frequency phase.
pensated for by "turning up" the bass
Either an a .c. millivoltmeter or a discontrol. Music of the organ and the bass tortion analyzer can be used for the disill'um require very high power output tortion indicator. The ' accuracy of the
in the region of 30 to 100 cps when bass cancellation is much less critical when a
boost is used.
filter-type distortion meter is used.
Oscilloscope measurements with mon- Measurements using this technique can
ophonic musical input signals fed to be made as low as 0.001 per cent.
both channels show that the clipping
Measuring the other characteristics of
: 52
the amplifier required no special equipment other than a switch and an attenuator to allow the use of the same a.c.
vtvm to measure both the input and output voltages when checking the frequency response. The frequency response
at the main speaker output, shown in
Fig. 9 for the left channel, is flat within
plus or minus 0.1 db from 15 cps to
45,000 cps and down 3 db above 100,000
cps. The internal impedance, which
reaches a maximum of 0.04 ohms from
10 cps to 20,000 cps, is so low that there
is no measurable change in frequency
response up to 20,000 cps whether the
load is connected or not. The clean
square-wave output accompanying this
frequency response is shown in Fig. 10
for 50 cps and 10,000 cps at 2 volts
peak-to-peak output.
In spite of the high sensitivity of 0.2
volts rms input for 20 volts output the
noise and hum are down 93 db corresponding to 4.5 microvolts referred to
a shorted input. With both inputs open
the increased source impedance for Q I
raises the noise to - 83 db in the poorer
channel. Channel separation is 72 db at
2000 cps where crosstalk is most objectionable and is at least 57 db from 15
cps to 20,000 cps in both channels.
Care of Transistor Amplifiers
With the hi-fi industry just entering
the era of transistorization a certain
amount of education is required in the
use of transistor amplifiers. While physically more rugged than vacuum tube
equipment, they cannot be subjected to
the same electrical overloads that vae,uum tube equipment can survive. Dealers will have to check the switching systems in their display rooms to be sure
the output terminals of a transistor amplifier are never short circuited. A millisecond short circuit is all it takes to
destroy a complete set of power transistors in one channel.
Short-circuit protection, while feasible, does not appear to be economical
yet since it requires considerable added
circuitry. It is not a simple matter
of adding a fuse in series with the output since what is needed is a dissipation
limiter rather thim a current limiter.
At high output voltages the amplifier
can safely deliver high currents, but at
low output voltages it can deliver much
less current without exceeding the dissipation limit of the power transistors.
Furthermore at low frequencies it is the
instantaneous dissipation that should be
limited, while at high frequencies it' is
the average dissipation that should be
limited.
Sustained high-frequency signals must
be avoided too_ Just as sustained highfrequency signals can overheat the
screen grids in a vacuum tube amplifier,
they also can overheat the junctions in
(Continued on page 86)
AUDIO
,- . NOVEMBER, 1962
A Headphone Control Center
For Monaural, Diotic, and
Binaural Listening
ROBERT J. LARSON ~' and
JOHN M. EARGLP
A headphone control center incorporating the CBS-Bauer crossfeed network which effectively
converts stereophonic information into binaural information appropriate for headphone listening.
in popularity of so-called stereo headphones,
there has been a trend in the recording industry toward more and more separation between channels. Reminiscent as
this is of the "ping-pong" era of ster eophonic records, it still is being pointed
to as a move forward in the art. Certainly many of the techniques employed
in this type of recording are advanced
and sophisticated, but patently the reason for such "super" stereo is to give
some notion of p erspective when these
I'ecords are played on phonographs with
stereo speakers a small distance apart so
that conventional stereo is hardly discernible from mono.
Our purpose is not to evaluate recording techniques but rather to examine
means for making the more extreme of
these techniques compatible with headp hone listening.
A circuit developed by Benjamin
C
ONCURRENT W ITH THE RISE
1001.1
600w
Fig. 2 . Origi na l
Bauer cross - fee d
network.
600w
+
Bauer of CBS Laboratories for converting stereo information into binaural information has previously been discussed
in detail/ and only its barest exposition
will be presented here. What we will discuss in detail is how the "Bauer Cir1 B enjamin
B. Bauer, "Stereophonic
earphones and binaural loudspeakers,"
J .A..E.S., vol. 9, no. 2, pp . 148-151; April,
1961.
* J ensen Manujactu?'ing Co ., 6601 S .
La.?'a1nie A. ve ., Chicago, Ill.
~
'"
!:~I I I
I
>-
~
o
I
I
I
I
+10
LEFT EAR
+5
/
1'-----/ ~
"'------
-5
- 10
n
;v
V J\V-
/
RiGHT EAR
-I 5
so
100
200
500
1000
2000
5000
10 ,000
FREQUENCY IN CYCLES PE R SECOND
Fig. 1. Relative response at ears of listener for sound source 45-deg. t o left of
listeners plane of symmetry, normalized to zero-deg. Incidence. (After Wiener.)
AUDIO
•
NOVEMBER, 1962
cuit,"2 as it is gener ally known, was incorpor ated into a control center for headphone listening and how the control center was designed, how it functions, and
the effect of a variety of recorded material.
The Problem and Solution
The problem is clear: stereophonic recordings made with microphones spaced
adequately for the reproduction of p erspective over loudspeakers do not give a
proper perspective when reproduced over
headphones. While the effect of such listening may not be unpleasant, it in no
way approximates natural binaural listening. An obvious solution would be
simply to introduce crosstalk between
the channels to whatever extent is necessary to destroy some of the gross separation which is encountered. 3 A more sophisticated solution is that offered by
Bauer, and that is the introduction of
crossfeed between the two phones which
approaches the phase and magnitude dif2 Licensed by Jensen Mfg. Co. from CBS
L aboratories Division of Columbia Broad·
casting System.
3 One prominent record reviewer who is
an avid headphone enthusiast suggests that
90 per cent crossfeed between phones is not
an excessive amount.
55
F i g. 3 .
Spa c e
tive he a
control
Model
II
Jensen
Perspecd ph 0 n e
center,
C(.l .
wearing stereo headphones, only one ear
will hear the event, and the resulting
localization will be unnatural.
Bauer 's solution to the problem is to
introduce crossf eed between the channels
in such a way that the resultant phasors
for an event in, say, the left channel will
be equivalent to the phasors of a sound
source locatt d 45 deg. to the left of the
listener's plane of sy= etry. With the
B auer circuit the listener will actually
sense the direction of exclusive events in
either channel as either 45 deg. to the
right or to the left; without the circuit
he is mer ely confused.
Bauer's calculated crossfeed is based
ferences between the ears r esulting from
the diffraction of sound around the head
during normal listening. His attempt
then is to provide the ears with binaural
clues so that localization with headphones
will approximate the natural localization
process.
A simple example will make the technique clear: Assume that a stereo recording has a signal in channel A which does
not appear in channel B at all. When
this recording is played over stereo loudsp eakers the virtual source will be at
sp eaker A, and the localization process
will be normal in every r esp ect. Now, if
this r ecording is played for a listener
VOL
D
3
8
3
o
o
LEFT INPUT
on head di1Iraction of Wiener 4, shown in
Fig. 1. The graphs show the level differ ences and time delay of sounds r eceived at each ear for a source 45 deg. to
the left of the listener . The circuit used
by Bauer to approximate this diffraction
is given in F ig. 2.
Because of circuit symmetry the crossfeed action is the same f or both channels,
and all sounds in the recording r egardless of their mutual exclusion in the r ecording process, will appear with the
Bauer circuit as they would with stereo
sp eakers located 45 deg . to either side
of the listener's plane of symmetry.
If a third microphone has been fe d
equally into both channels (a fairly cof mon technique in stereo recording ), then
its virtual source will be on axis, the
same with the B auer circuit as without
since by sy=etry there is no crossf eed
when equal voltages are f ed by the
sources.
Another case which should be mentioned is the use of microphones whose
pickup p atterns overlap. Wher e there is
significant signal mutuality between
channels r esulting from overlapping
pickup patterns, the resultant magnitude
differ ences and time delays make a precise phasor analysis difficult. But listening tests bear out what is suspectedthat the virtual sources for these events
always tend toward the center of the
± 45 deg. allowable angle.
Application of the Bauer Circuit
RIGHT INPUT
3
8
RIGHT SPKR .
0----0
51 w
I
SW2
SWI
A - SPEAKERS
B - PHONE S
ABCD-
SW3
LEFT O NLY
RIGHT ONL Y
REVERSE
NORMAL
A - MON O
B - STEREO
C - SPACE PER SPECTIVE
Fig . 4 Schematic of J ensen CC-l.
SO LI D LI NES, TRANSMISS ION CHARACTER ISTI CS OF CC- I
+10 . , - - - DOTTED LINES , WIENE R DIFFRACTION DATA
+5
,- .-
o
~
Z
~
--
-5
.- .-
,
,
~~ , , ,
~
['\\,'"I,
1-' ,
,
\
.- I
I
\
"
/
/'"
1\
,~
- 10
~
',X
--
-I 5
-20
-25
50
lao
200
500
1000
2000
"'"'"
5000
( Cont i n1£ed on page 89 )
10,000
FR EQ UEN CY IN CYCLE S PER SECOND
Fig . 5 . Wiener diffraction data compared with transmission characteristics of CC-l.
56
The Bauer circuit principle has been
incorpor ated into a contr ol center for
ster eo headphone listening (by J ensen
under the name Space Persp ective5 and
Model number CC-l ) . The control center is normally introduced into a high
fldelity system following the power amplifiers. One of its five controls feeds the
incoming signals to either loudspeakers
or phones. The others affect only the
phones, providing left-only, right-only,
ster eo, and ster eo-r everse operation, with
or without Space Perspective, and p ermit adjustment of balance and over-ali
listening level.
The commer cial control center is shown
in F'ig. 3 ·and its schematic in F ig. 4. It
can be located in a chair-side position by
the use of th e propel' length of cable.
The multiplicity of controls allows complete flexibility in listening to all kinds
of r ecorded material and in demonstrating the unit's salient f eature, sp ace p ersp ective. For example, either channel
can be heard easily with or without Cl'OSSfeed so that its eff ect can be clearly obser ved.
1 Fra ncis M . Wiener, " On th e diffraction
of a progressi ve sound wave by the hum an
head," J . A. S. A ., 19, pp. 143-146; 1947.
5 TM. Jen sen Mfg. Co.
AUDIO
•
NOVEMBER, 1962
T
HIS MAN is 110t disturbing his wife while he listens to a stereo concert ... and he's
sitting out in the audience where he wants to be . .. not in the middle of the orchestra
(where he'd be with ordinary headphone stereo). Right by his hand he can control
volume; adjust left.right balance to suit the music source and the best hearing conditions
for him; switch from mono to stereo, or stereo with SPACE·PERSPECTIVE*; individually
select and / or reverse channels; switch speaker system. 'Phone jacks for two. All this in
jensen's new CC-1 Headphone Control Center with SPACE·PERSPECTIVE ... an attrac·
tive, compact, versatile unit you can place anywhere . . . even hang on the wall.
What makes the extra difference is SPACE· PERSPECTIVE .. the amazing headphone
development which approximates more closely the sensation of listening to a stereo speaker
system in a room. In ordinary headphone listening, left channel sound is confined to the
left ear, and right channel sound to the right ear. In stereo speaker listening, sound from
the left speaker reaches the left ear and also the right ear by means of the natural diffraction
of sound waves around the head; and right speaker sound will reach the left ear in the same
manner, thus resulting in what we all recognize as natural stereo sound in realistic perspec·
tive. SPACE· PERSPECTIVE adds this diffraction, which is missing in ordinary headphone
listening, by electrically cross· feeding sound from one channel to the other to simulate the
passage of sound waves around the head . You are now "in front of the speakers" via head·
phones
. not in the middle where the sounds are isolated to each ear.
The CC-1 will operate with some other stereo headphones ... but for best results the
Jensen HS·1 'phones are recommended ... the new professional stereo headphones which
offer the most advanced features for top acoustical performance and comfort. The CC-1
Control Center sells for $39.95 .. . HS· 1 Stereo Headphones for $24.95 .. " and a CFN·1
SPACE·PERSPECTIVE network only, with input jack, for $19.50. Write for Brochure MH.
Jensen Manufacturing Company, Division of The Muter Company, 6601 S. Laramie Ave.,
Chicago 38, Illinois .
- T.M. Ucensed by CBS Laboratories Division, Columbia Broadcasting Sy,tem, Inc.
AUDIO
•
NOVEMBER, 1962
57
LIGHT LISTENING
(from page 8)
Three with its performan ce of S leigh R'ide
that some son ic activity becomes noticeable
on the outlying ends of the listening region .
The r est of the record is satisfactory in
s tereo spread with Jazz Pizzicato placing th e
\'iolins a ll the way to the left border. Anderso n's Syncopated Clock ha s its num erou s
horologica l sound effects well scattered for
maximum effect and the spoofing of some of
t h e more pompou s symphonic fare in Cla ssical Juke Boa: takes place within a large
enough orchestra l layou t . If this release had
heen gil'en something like the can venti an a l
Pops miking, it wonld have been t h e fin a l
wo r d on the subject of Lero y Anderson. The
Boston Pops has a lways been the horne base
for his music from t h e time h e first a ttracted
nationa l attention as one of its arranger s and
orch estrators. As matters sta nd now, w e h ave
[lerformances that should take care of these
tunes indefinitel y but I cannot avoid the concl usion that the stereo is by no mean s th e
best tha t RCA can give u s.
Touchdown, U.S.A.
Vanguard Tape VTC 1647
In many cases today the tape version of a n
outstanding r eco rding (and some not so outstan din g) a ppears several w eeks after the
disc version has h it the market. For some
unknown r eason, United Stereo T a p es n ever
go t around to issuing th is exception a lly fin e
collection of football marches pla yed by th e
University of Michigan Band which Vanguard
Reco rds brought out on disc on e yea r ago.
S ince the demand for footba ll songs do esn't
seem to he a ravenous on e out of season, UST
decided to hold off the tape until this current
nutumn sent us back to the nation' s stadia.
Record collectors are w ell aware by now that
the University of M ichigan ta],es its band
ac tivities very seriously. 350 players in all
a r e to be found i n the three divisions of t h e
enormou s enterprise r efe rred to as the "Unive rsity of Michigan Bands." One d ivision is
the March i ng Band, husy at a ll home football
games and travelling with the tea m when it
in vades enemy territory. Another group is
t he Varsity Band which takes care of baske tball games and other fun ctions on campus.
Tbe ba nd b eard here is th e University of
U ich igan Symphony Band. T h is is th e top
aggregation at the oldest of the "Big T en"
universities ~ It was the first major unive r s ity
band to g ive extensi ve nation-wide concert
to urs. In the spring of 1961, th e band gave
88 co nce rts durin g a fifte en week tour of
Eastern Europe and the Middle East sponsor ed by the U.S. Dept. of State as part of
the Inte rnational Cultural Exch a nge Program. It was hardly surprising, t h erefore,
that the band 's r ecord of a year ago offered
someth i ng quite special in the treatm ent of
seventee n footba ll marches which included
representa tion of each univer sity in the "Big
T en ." The presen t r eel version is s ure to deli ght any tape fa n car r y ing a round a pu lse
sti ll capable of being accelerated . Already
announced for r elease this f a ll are two more
record ings by this outfit on the Vanguard
label-"The Univers ity of Michigan Band on
Tour" a nd "Sousa." They 'll be worth watching for.
Anything Goes
Epic FLS 15 100
Nearly tbirt,v years aft er its fir st appea rance o n Broadway, Cole Porter' s fa mou s
musical is now a New York off-Broadway
attraction. In bringing "Anything Goes" to
r ecords, Epic gives us our fi rst opportunity
to h ear t h is brash favorite of the Thirties in
perform a n ce by a cast that has actually
face d a n a udience. The young playe r s of the
1962 production ·can hardly be expected to
er ase t he memories that some of us still
reta in of the original star-studded ca st that
was headed by Ethel Merma n, Victor Moore,
58
nnd WilHam Gaxton. This a lbum's cast faces
less competition on records th an it does
back in t h e annals of the theatre. For many
Yea r s, w e've bad to be co ntent with the
p a rtia l glimpse of the s how that h a d been
r evealed to u s on r eco rds in Mary Ma rtin 's
wid ely
admired
mono
album-Columbia
M4751. In that r elease, Miss Martin cover ed
Il s u rpri sin gly large port ion of the score in
performances deli vered with the ass is ta nce of
nn orchestra a nd cborus under the direction
of L ehman Engel. It is perhaps worthy of
passin g rem ark that this new Epic production covers only three more songs from the
score.
Eileen Rodger s. last seen on Broadway in
"Fiorello" and "Tenderloin ," is the sta r of
th e latest revival. Her singin g style, although
not as poised a s Mary Martin' s, does come
closer to the burnished sou nd that Ethel
Merman once brought to the familia r lyrics
of You're th e Top, Blow, Gabriel, Blow, a nd
I Get a Kick Out of You. Mickey D eem s, the
comedy directo r for the current TV hit, "Car
54, Wh e r e Are You?" appears in the role
made famous by Victor Moore. As Public
Enemy Number 13, Deems h as his major solo
mom en t in Be Like the Bluebi,·d. The produ cer s of this r evival evidently felt the n eed
for a n added quota of Cole P ort er tunes t o
bolster their prod uction. They have interpolated a fa irly large total of six other tunes
that a ppea r in Porter shows that preceded
and followed t h e initial Broa dway a ppeara n ce of "Anything Goes." Since t he Epic
r elease closel y follows the stage production
t hat h as been running in Greenwich Village,
it is som ething of a shock to encounter on
board tbe "S.S, America" s uch other Porter
diehards as it's Delove ly from the 1936 show
"Red, Hot and Blue," and F"iendshi p from
t he 1939 opus "Dubarry Was a Lady." The
sound of the small orches tra under the direction of J u lian Stein is typical of the s malle r
o utfits gen erally found in theatres below Ma n h attan 's 14th Street. Once you ge t used to it,
you 'll scarcely miss the flo ssier pit ba nds that
are tllken f or granted on the Main Stem.
Ethel Me rman
Reprise R-6032
Della Reese: Della on Stage
RCA Victo r LSP 2568
It's Il pleasa nt coin cidence to encounter a
new Eth el Merman a lbum during the same
month that h er old show, "Anything Goes," is
revived on reco rds. Li stening to Miss Merma n 's r ecollection of th e great songs of her
ca r eer, in cluding three tunes from that Cole
Porter classic, it is somewhat staggering to
realize that 32 year s have gone by since th e
fi ,'st Merman s how made her name a byword
in the entertainment world. No attempt is
made in this a l bum to follow a precise chronology of h er musicals desp ite the f ac t that
t h e opening tune is I Got Rhyt hm from the
production that introduced t he Merman style
to musical comedy andiences-George and
Ira Gershwin's "Girl Crazy." During the r est
of · that fantastic Thirties d ecade, Ethel Me rman a ppeared in a total of seven Broadway
musicals. A top star in those days evidently
h a d no problem finding Il new s how. As soon
as one production showed signs of faltering,
a n oth e r on e WIlS waiting to make n se of h er
talen ts. In a ddition to Porter, Miss Merman
worked fo r many leadin g song teams of the
d ay ... Henderson a nd Brown , Richard Whiting and Buddy D eSylva, a nd A rthur Schwartz
and Dorothy Fields. Th e only item in this
co llection n ot u sually associated with the
s in ger is t he sentimenta l ba llad But N ot For
Me from the score of "Girl Crazy_" M iss Merman obviously welcomed the opportunity to
choose some of her own r epertory today after
a ll these years of being aSSigned a fairly
specialized type of song. Billy May, long
associated with a rhythm of b a rd-driving
bounce, was a logical enough choice to arrange and conduct the selections heard in
Ethel Merman's first appearance with a
swinging orchestr a .
D ella Reese, in her latest RCA a lbum, r ever ses the procednre followed In the Merman
r elease. Instead of moving from t he footligh ts to a r ecording studio, Miss Reese moves
a specially invited a udience into the la r ge
studio at Manhattan's W ebster Hall where
she proceeds to beat them into a h a ppy pulp
with h er h a mme rin g d eliver y of a collection
of standa rds, s piritu a ls an d blues. With the
exception of S omeday, h er special hit on
s ingle r ecords, non e of the mate rial h ear d
h er e h as ever been recorded before by D ella
Reese. A bonus for h er more ardent fans is
the running stream of encouraging patter she
provides between selections.
Dick Lie bert: Great Love Themes
Rep rise 9-6037
During all the years Dick Liebert has been
busy at the con sole of the Radio City Music
Hall organ, h e h as invariably reached his
largest audience after the last show of the
day was over. His recordin g sessions gen era lly begin after midnight as soon as the vast
aud itorium h a s been aba ndoned by the d ay's
a udien ce. During the a ll-night session that
gave Reprise this record, a crew of sixteen
technicians worked with Liebert to get on
tape the s ubtle s h a dings of a prog r a m devoted
excl u sivel y to music design ed for late evening
li stening . This is one of the few orga n records
a round that doesn ' t i nclude a novelty or two
fo r ch a n ge of pace. If you have no objection
to one mood sustained throughou t an en tire
record, this could be your dish . Some organ
fa n s on the other h a nd, may appreciate a
word of warning a bout the undevia ting
natu r e of a progra m that never moves far
away from the M oon Love and Lamp Is Low
so rt of thing. Liebert gets around the problem to some exten t in his choice of keyboard
voices. Ma ny of the tunes spotligh t the orga n 's equiva lent of str ing instruments. A
cello is imitated in Till the End Of Time, a
viola during Full Moon and Empty Arms and
a violin In Toni ght We Love. A Mason and
Hamlin pi a no, wired to the organ' s l,eyboard
a t Il r epnted cost of $25,000, repays some of
t hat investment in the course of Song 01 Love
based on Schubert's "Unfinished Symphony."
T echnical proficiency in the processing of the
disc could best be described as almost tops.
Martyn Green : The Gilbert and Sullivan
Songbook
MGM Tape 'STC 3 980
There are instances when the tape version
of a r elease is s uperior to the disc Ilnd this
happen s to be one of them . Wh en this collection of Gilbert a nd S u llivan songs first
m a de its appearance on d iscs toward the
close of 1961, it made onl y a moderate stir
in record circles. It's h a rd to pred ict h ow
lU a n y n ew roote rs this album will a ttract in
tape form but I'll v enture the opinion th at
most listen er s familiar only with Martyn
Gr een's MGM record will get an added kick
when they h e ar his virtuoso performance on
tape. The clean processing accorded this reel,
combin ed with sen sible ba lance in equali zat ion, gives t a pe an unusual oppor t unity to
demonstrate what it ca n do in bringing out
t he s ubtlety of inflec tion a rea l Singing actor
is ca pable of in t he late r stages of a long
car eer . It may surprise even those G and S
fa ns who u sed to look forward to each of bi s
famous 78-r pm a lhums that Martyn Green
has been speaking and Singing the lyrics of
Sir WilHam Gilbert for t hirty-eight years. No
one is better qualified to instru ct our generation in the fin er points of r ec reating a n era
filled with characters who m a naged pomp in
any circnmsta nce. The British r ecording
crew t r eats Green with obvious affection.
Since h e is pre tty much the whole show, the
engineers were a ble to work much closer in
each song than they would h ave in a recording session empioying a full cast in a complete production. When Green launches into
AUDIO
•
NOVEMBER, 1962
SOUNDT LK
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against wea r, helps maintai n ga p tol erance (a bove) and preserve the full frequency response of record er heads and
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deserve the exclusive protection of Silicone lubrication that's available only in " SCOTCH" BRAND
Recording Tapes and lasts the lifetime of the tape.
Silicone lubri cation not only protects against
wear- it extends tape life, eliminates chance of
squeal by assuring smooth tape travel! Silicone
lubrication is impregnated thro ughout the oxide
coating of all " SCOTCH" Recording Tapes. It's
comple tely clean and · dry-nothing gummy to
attract rust or clog h ead gap.
This built-in lubrication is one of many reasons why professionals and discriminating h ome
recordists alike insist on " SCOTCH" Recording
Tapes. High -poten cy oxides make possible thinner,
more flexible coa tings that ensure intimate headto-tape contact for maximum frequen cy response,
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backing and coating thicknesses assure identical
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yo ur equip-ment (4, 2 or full track) we suggest
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AUD IO
•
NOVEMBER, 1962
3m
59
Getting The Most Out Of Your Tape Recorder
.High Fidelity Simplified
Harold D. Weiler
Herman Burstein
Qrd Edition:]
Written
the man
10 buy,
answers
The complete hi-fi storyanswe rs all ques tions a bo ut
the
myriad
Ques-
tions raised by tope reco rd -
tun ers, chong ers, amplifiers,
tope re corders, speakers,
record players, etc. Lots o f
ideas for cu sto m installations. Te lls how to achi eve
concert hall reception in
you r home. 216 pages .
No. 142
in "p lain ta l k" for
who has, o r w i shes
a lope recorder. 1t
in g enthus iasts. l is chapters
cover every phase of ope ration and maintenance-from
ad d in g a lape recorder to
the h i -fi system, to a thorough disserta t ion on micro phones. lois of pract i col
i nformation o n how to buy.
$3.30
some of his choice speCialties fr om productions such as "Pirates of Pen zance," "Prin cess Ida," or "Trial by Jury," this tape seeks
ou t each tiny quaver in t he po r trayal or
character . Here's one recording of G an d S
operettas that requires no libretto to assist
t he listen er in following t h e l yriCS . Sin ce no
single performer could be expected to convey
the atmosph ere of the eight productions r epr esented hel'e, June Bronhill a nd And rew
Gold take car e of some of t h e roles whose
paths bappen to cross t h at of tile cbaracters
portrayed by Martyn Green . Ornadel . leads
the orchestr a in arrangements by Rober t
Crels that r esto re m uch of the freshn ess this
music once had befo re it became encrusted
w ith years of half-hearted performance by
h igh school orcbestras . While in no way :l
complete substitute for the f ull·length G and
S productions available to tape fa ns on reels
issued by London Records, this tltre is bound
to be one of the most frequently played item s
i n a n y Gilbert and Su llivan librllry .
176 pages.
No. 251
$4.25
George Chakiris
Capitol ST 1750
McProud High Fidelity Omnibook
Prepared and edited by
C. G . McProud, publisher
of Audio and noted authority a'nd pioneer in
the field of high fidelity .
Contains a wealth of
ideas, how to 's, what
to 's, and when to 's, written so plainly that both
engineer and layman can
appreciate its valuable
contex t. Covers planning,
problems w ith decoration,
cabinets and build ing hifi furniture. A p e rfecr
guide.
No, liS $2.50'
Handbook of
Sound Reproduction
Tape Recorders and Tape Recording "
Harold D. Weiler
A new compendium of
AUDIO knowledge. Here
is a collection of the
best of AUD 10 - The
AUD 10 Clinic by Joseph
Giovanelli . . • noted
audio engineer and the
original high fidelity answer·man - EQUIPMENT
PROFI LES edited by C. G.
McProud . . . Editor of
AUDIO. Here is a wealth
of hi-fi and audio infor·
mation. Answers to the
most important issues in
high fideli~y and a valu·
able reference.
No. 124 Volume I $2.00 *
A complete book on home
recording by the author
of High Fidelity Simp/ified. Ea sy to read and
learn the techniques re ..
quired for professional
results with hom e re ...
corders . Co ve rs 'room
acoustics, microphone
techniques, sound effects,
editing and splicing, etc.
Invaluable to recording
enthusiasts.
No. 112 Paper Cover $2.95 .
MONTHLY SPECIAL!
SAVE $5.25
Save over 45 % with this collection of AUDIO Books.
Handbook of Sound Reproduction ($3 .75) "best of AUDIO" ($2 .00)
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Tape Recorders & Tape Recording ($2.95)
TOTAL V ALU E OF ALL FOU R BOOKS $11.20
Your cost ONLY $5.95 POSTPAID
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30, 1962.
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Please send me the books I have circled below. I am enclosing the
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110
112
142
115
251
124
OS300
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Same
Choreo AS-7
Edgar M. Villchur
Right up to date, a complete course on sound re·
production. Covers every·
thing from the basic
elements to individual
chapters of eoch of the
imporkmt components of
a high fidelity system.
No. 110 $3.75*
"the best of AUDIO" edited by C. G. McProud
•
J<lmes Shigeta: We Speak the
language
Two yo u ng motion picture lumin aries mak e
th ei r solo debuts on r ecords this month. In
dOing so. t hey underlin e on ce more how dependent tbe record companies are on the Initiative of the movies wben it comes to spotting and developi n g n ew ta lent. Chaklrls
comes to reco rds after a whirlwind climb in
show bus in ess that began to gain its real
momen tum after a twenty-month run on the
London stage when he was selected to play
t he role of Bernardo in th e recen t film version of Leonard Bernstein's "West Side
Story." Along the way, Chaki ri s h asn't had
too m uch opportunity to smooth out every
wrinkle in his sin gin g style. His breath con t r ol is apt to get a bit out of hand In more
formal m u sic sucb as Victor H e r bert's ],,,,
Falling in. Love 1.vith Som,eone which calls for
conside rable po ise on the part of the performer . Quite un derstandably , he h as his hest
snccess In the two excer pts f rom " , Vest Side
Story" . . . Tonight and lJfal'ia. A,noth er
Broadway product ion, the top-ranking "How
to Succeed in Business Wi thou t Really Try·
ing," provides a good cl ue to Chaldris' fut u re
ha ndling of show materia l in general. In
I BeUeve 'ifft Yo", by no means the easiest
song Robert Morse h ammers home in t h at hi t
sco re, Greorge Chak iris p u ts on display the
warIn showmansh i p of a rising star. Re' n
bea r watch ing.
The Choreo label dist ributed by 1110:111 Records introduces a promising new talent in
the person of Hawaiian-born Jam es Shigeta.
His career so fa r pOints up t he value of going
Horace Greeley one better and moving w est
from his native land-all the way to Japan .
After a stint at New York Un i vers it.v-whe '·e
he discovered that m u sic was more importan t
to him than creati ve writing-Sh igeta took
his first step to\yard a professio n al career
when he placed first in a T ed Mack Amateur
Hour. The Korean War soo n h ad him in :l
Marin e uniform. When h e abandoned hi s
Staff Sergeant stri pes two and one h a lf years
later, Shigeta started singing again and accepted the lead in a musical revue to be
produ ced in Japan. In that somewh at im ·
probable spawn ing gro un d for a film career,
he found an entra nce to Hollywood. Jim
Shigeta became the toast of I n,pan on th e
basis of his record of Love Lette't s in the
Sand w hich sold more t h an two million
copies. Afte r that it was a short step to
Japan ese television and stage shows with the
aid of a tutor hired to hel p hi m unravel tIle
mysteries of an Oriental language. Wh en
word of his u n usual acbievemen t reached the
States, h e was engaged to appear with Shirley MacLaine on the Chevy Show. Then followed American screen appeara nces in "Th e
Crimson Kimono," " \Va lk Lilre a Dragon/ '
"Bridge to the Sun ," and his first American
film singin g r ole in "Flower Drum Song."
With a list of credits that long it's no wonder
that Shigeta turns in a recording that is
heads and shoulders above t he usual debu t
release.
.1E
AUDIO
•
NOVEMBER, 1962
SPEC,IIAL PRE=/PUBLlICA TtlO,N O'FFER ~
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The SIXTH AUDIO ANTHOLOGY includes articles on two most
significant milestones in the field
of high fidelity: FM STEREO and
TRANSISTORS IN AUDIO
EQUIPMENT .• The FM STEREO articles which ~ppeared in
AUDIO - the originql magazine
about high fidelity - were written
by the men who actually worked
on the system approved by the
FCC. The articles pertaining to
TRANSISTORS IN AUDIO APPLICATIONS cover interesting
aspects of designing with the semiconductor. -As in previous editions of the AUDIO ANTHOLOGY, the SIXTH is a compilation
of important articles which appeared in AUDIO over a period of
about two years. And, all of the
articles were written by knowledgeable and experienced authorities in the field. -The SIXTH
AUDIO ANTHOLOGY is a
meaningful reference for everyone
in the diverse fields, of audio enginee ring , recording, broadcasting,
man ufacturing and servicing of
components and equipment, and
for the audio fans who made this
business of high fidelity what it is
today.
' Save another $1 by ordering the 5th
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HEATHKIT STEREO TAPE
RECORDER, MODEL AD-22
. The Heathkit Model AD-22 tape recorder
a 2-track machine designed to record
and play 4-track mono and stereo with
record bias and audio output being supplied from the built-in preamp. The AD-22
is supplied in kit form (or preassembled)
and is a kit in the old sense of the word~
the only parts that are preassembled are
the capstan bearing assembly and the main
wiring harness. Of course we are all aware
of the tr.end ~o package and partially assemble kit umts, to the extent that some
normally complex kits can be assembled in
a mere handful of hours. This latter category is really quite ideal for the audiofan
who wishes to save a little money and also
get a much closer look at the insides of his
audio system. On the other hand, the experienced audio fan who wishes to save
more will gravitate towards the less elegant
package such as this Heathkit unit.
For example we found, on opening the
box, that all the small parts were dumped
into two moderate-size brown-paper bags.
Of course the experienced builder immediately sorts out the parts in some neat array
-in fact this procedure is suggested in the
manual. On the other hand, it is not diffiIS
cult to inIagine the reaction of the less
experienced builder; the hopeless feeling
when confronted with a jumbled mass of
parts which are not familiar to him. For
the latter reason we would suggest that
the less experienced builder would be wise
to be prepared emotionally and have sufficient available time before tackling this
kit.
Insofar as time is concerned it took us
just a hair over 16 hours to get the AD-22
put together and operating correctly. It
would have taken us somewhat less but we
found the mechauical readjustments rather
tinIe consuming. We will go into that aspect later.
On the whole, we found the AD-22 to be
a good performer, basically satisfying the
need for a moderately priced tape deck. In
addition, the AD·22 is a very uncomplicated
and relatively rugged machine which should
provide a good level of performance for a
long time.
Mechanical Circuit
The driving power for the mechanical
system is supplied by a single-speed induction motor which is coupled to the capstan
by means of a round rubber belt. (Actually
the motor drives a rather substantial flywheel wh~ch in turn drives the capstan.)
The AD-22 is a 2·speed machine and speed
selection is achieved by raising or lowering
the shaft just to t.he rear of the head cover
-in the up position the speed is 7% ips
and down it is 3% ips. The capstan speed
is determined by the size ratio between the
motor pulley and the capstan flywheel: the
motor pulley is two-stepped, the smaller
step being for 3 % ips and the larger fo r
7lj2 ips. This system of moving the belt
from a larger to a smaller diameter (7lj2to-3% ips) requires a belt which does not
stretch, a stringent requirement. On the
other hand it has the advantage of being
unusually simple. Also, the speed that
would suffer if the belt stretched is 3%
ips which is not a serious loss in many
cases. The method whereby the belt is
shifted is also rather simple: the shaft
which projects above the deck moves a
forked finger that straddles the belt, and
the belt moves down or up to follow if the
motor is rotating.
In the play or record positions, the tape
is clamped to the capstan by the capstan
idler thus moving the tape toward the takeup reel. At the same time the takeup reel
is driven forward by a belt which runs between it and a pulley mounted below the
capstan idler. Thus the motion of the
capstan is transmitted to the capstan idler
and from there to the takeup reel. Head
pressure is achieved by means of a springloaded compliance arm between the capstan and the takeup reel and also by a
holdback arm whose felt face presses the
tape against the tape guide located between
the supply reel and the head assembly.
There are no pressure pads to grind the
tape across the head. Also there are no
tape lifters to take the tape away from the
head during fast forward or rewind.
Fast forward is accomplished by mechanically shifting the takeup brake drum so
that it presses against a rubber surface on
the motor pulley. Rewind is accomplished
by pressing the supply brake drum against
a rubber-faced idler which in turn presses
against a smooth surface on the motor
pulley.
The forward oblique rewind control may
be turned from one position to the other
without pausing for the neutral position BO
that the tape may be "jockeyed" easily to
locate a particular passage. The play control however is locked in neutral when the
forward oblique rewind control is being
operated. This precaution is necessary to
prevent the tape from being broken by
switching too fast from rewind to play.
In essence then, the mechanical circuit
consists of a single-speed induction motor
driving the capstan system by means of a
belt in order to reduce flutter, while the
fast speeds are direct or idler driven to
accomplish their mission as quickly as possible. The concept and execution are simple.
Electrical Circuit
Fig. 1. Heathkit stereo tape recorder, Model AD-22.
62
The electrical circuit for the playback
preamplifier is extremely simple since it is
very limited in function; all it has to do is
amplify the signal from the playback head,
produce the proper NAB playback equalization, and send this signal out to the rest
of audio system in proper style. To accomplish these simple purposes, the preamp
utilizes three stages of amplification (actuually three tube sections VIA, V,n, and V u )
and a cathode follower output stage, V,n.
(We will not make mention of tube types
since the only type used in the preamp
is the 6EU7, a twin triode.) NAB equalization is applied at VIA. with the internal resistance of the tube and its plate-load resistor being part of the equalization circuit.
It should be noted that special attention is
exhibited in the low-level stages in that
low-noise resistors are used in the cathode
AUDIO
•
NOVEMBER, 1962
'~udio" confirms
this
.
IS
a
When we termed our loudspeaker "dangerous," we
expected confirmation by experts. But we never expected
everyone to agree. Always there is one dissenter. Who will
it be?
It is not Audio Magazine. Quite the reverse. In their
September issue, Audio said: "The EMI Model DLS·529
is a true 'bookshelf' speaker in size ... and far from bookshelf in sound ." As we said, the DLS-529 is dangerous
because it demands reappraisal of previously· accepted
standard of excellence. And please don't ask us to redesign it to make it sound like an ordinary bookshelf loud·
speaker (even though it costs only $159.00*) .
Too, we called our loudspeaker dangerous because its
transient response reveals flaws in any equipment used
with it. Audio Magazine calls the transient response "fine"
and says, "(it) handles the frequency spectrum from 40
cps to 15,000 cps with realism and good precision, reo
sponding excellently to the attacks of some especially
heavy piano passages." Heavy piano passages are a trial
for everyone-from recording engineer to speaker designer.
And the transient response must be exceedingly fine to
"respond ex-<;ellently" to fierce piano attack.
,·$169.00 in south and west.
AUDIO
•
NOVEMBER, 1962
Audio also cites the DLS·529 for its bass, saying that
the "bass reproduction is of the tight variety." Of course
it is. But let Audio tell why we've designed it this way. "It
avoids," the journal reports, "the overblown fullness which
was characteristic of some speaker systems not many
yea rs ago."
A word to the stereo·minded about high frequency d~s­
persion. This function is the way sound "fans out" from
the drivers. If it's narrow, the stereo effect is poor. Audio
Magazine noticed that the DLS-529 's high frequency dispersion is "unusually smooth and rather wide." Audio also
said, "As might be expected, a pair of (these units) pro-I
vides really excellent stereo coverage."
And there you have it from the experts-unsolicited,
unqualified, undeniable confirmation anew of the dangers
of the dangerous loudspeaker.
For further information, write Scope Electronics Corporation, 10 Columbus Circle, New York 19, N.Y., exclusive
distributors of EMI Loudspeakers and Integrated Tone
Arms and Pickups.
~ .......
(ELECTRIC AND MUSICAL INDUSTRIES LTD.) ENGLAND
~.&r.& ...
63
anel plate ci rcuits of the first two stages in
each channel. In aelelition, in these stages,
el.c. heater bias anel hum·bucking pot entiom et ers are used to minimize hllll.
The reco1'(l circuit is, in a sense, the r everse of the playback circuit with several
necessary embellishments. First of all, th e
1'ecorel circuit accepts signals f r om both ::t
microphone Dnd/or a high-output source
such as a tuuer. This mak es it necessary to
have two sets of gain controls as well as
entry point at ruffer ent stages of amplification. Next it. has a VU-type meter for
monitoring the input signal in each channel before it r eaches the r ecorel heael. Also
record bias is necessary to enable the signal
to be recordeel on the t ape with minimulll
rustortion; this requires a bias oscillator.
Au er ase heael is provideel so that the t ape
carries liO signal by th e time it r eaches the
r ecord h ead. Finany, th e r ecording cur ve
(on th e tape) is th e inverse of the l)\a)"back cur ve; if the two curves wer e "added
up" t he r esultan t cur ve would be a straigllt
horizontal l;n e. In addition, r eco rd eq ual·
ization is different for the two speeels at
which this machin e ca n record, and thus
aelditional circuitry is necessary .
We will not give a stage-by-stage deelescription of th e r ecor d circuit becau e
it is rath er straightforward aJId without
any especially distinguishing characteristics. We sho uld melltion, howeve r, that the
bias oscillator tube i s a 12A U7 a.ncl the
oscillation frequency is 75,000 cps.
The power supply utilizes a full-wave
voltage doubler followed by a fo ur-section
filter network for tho B-plus voltage.
mounts most of the preamplifier circuitry .
Another ma;jor time and t emp er saver is
the prefabrica t ecl harn ess for the power
supply and oscillator chassis; the wires ar e
all neatly laced in position with breakQuts at th e proper location s to make wirihg simple. A r a ther nea t innova tion in t he
manual is th e combination of pictorial and
proced ur e in assembliug th e components to
th e cil'cuit board; the step-by-step proceelur e surrouud the pictorial of the board
with a rrows leading from the assembly
step to the component location on the
board.
The use of illustrations in the manual i s
almost lavish when compared wit h the t ype
and number found in mall uals a few years
ago. On t he other siele of the ledger, we
found some of t hem inconveniently placed.
As mentioJ leel previou ly, it took us 16
hours to assemble the AD-22 with a certain
amount of the time consum ed by r eadjustment s. We feel that is not likely that th e
mechanical adjustments will be complet ely
correct until th e entire unit is assembled
(we are not r eferring to t he difficulty we
described before). In r eality the possibility of checking mechanical operation is
not suggested until after the electrical assembly has been completed ancl installed.
vVe would suggest that t he motol' plug
be installed ,md plugged into a power
so urce, the knobs installed a nd the unit
checked prior to starting the electrical assembly. For one thing, the mechanical
"picture" will be f resh in mind, and second it will be easier t o get at the mechanism .
Construct ion
Performance
Previously we noted that a certa'in
a mount of experience might b e helpful in
constructing th e AD-22. We wer e r eferrin g
to the money-saving p ackaging concept
which H ea th pioneerecl. In addition to p arts
hanelling experience, a certain amount of
mechanical savoi7' ta,i7'e would b e extremely
helpful too. Let us hasten to say that this
is not a criticism of th e kit but r ather an
awareness of the inevitable mechanical adjustments and the difficulty in performing
some of them on a completed unit. It's not
just a matter of patience, that's not th e
type of experience we were r eferring to ,
but more a IDatter of being able to visualize how parts interrela t e.
For exa mple, we experienced some dif
ficulty getting the rewind fUllctioJliug
properly . F irst we consulted th e manual
in that sp ecial section devoted to difficult
problems. Unfortunately all the advice and
analysis offel'ed fa iled to locate the difficulty. Then we just propped th e m achine
up so that the recalcitra nt area was clearly
in view and proceeded to operate the r ewind control. Then the cause of the difficu lty became clear : the arm which is
supposed to move the rewind brake dr um
in contact with t he idler was not moving
far enough. It was then a matter of locating the point where the arm hael become snagged. This turned out to be not
as easy as we expected; th e arm had gotten
off its track in a rather hard-to-see way .
Anyhow, the point of all this is that mechanical adjustments can be more complex
than appears on t he surface a nd being
able to visualize operation is helpful.
In spite of th e previous ruscussion, the
AD-22 is really rath er sinlple to build,
both mechanically and electrically. The mechanical assembly was not in any way
complicated by "tight corners" or rufficultto-understand directions. To the contrary
we fiud the instr uctions concise and unambiguous.
Electrically, the AD -22 went together
with extreme ease. Contributing largely to
this is the printeel circnit board which
64
The most significant char act eristics f or a
tape recorder and playback machine ar e accurate speed, low distortion, high signal-
to-noise ratio, wid e frequ ency r es ponse, and
gooel separation b etween cha nnels. In addition, an importa nt characteristic is th e
way th e machine handles t ape.
In all these a reas the H ea thkit AD-22
performeel well, easily meeting the published specifications. (We would lik e to
point out that we h a \'e neve l' t est ed a
piece of Heath equipment whi ch didn't
meet all its published specifications easily
- and th e specifications a r e ins aTiably wen
defined and valid.) In the area of speed
accuracy we found it to be within 1 per
cent at 7 liz ips, and at that speeel wow
and flutter was 0.18 p er cent. T he harmonic distortion was specifieel w:ith >1 400cps signal using NAB pr ocedure, anel with
these conditions the distortion was 0.84
per cent. At the same r ecording level used
i ll the distortion t est , signal-to-noise ratio
was 47 db and channel separn tion was 40
db. Frequency r esponse at 7112 ips was
within 3 db f rom 40 to 15,000 cps as specifi eel although over most of the range it
was within 1 db. The playback eq ualization was within NAB limits.
There a re no published specifications for
t ap e h andling cap ability, but from our
experience we would classify the AD-22
as a m achin() which hanclles tape well. That
is, it hacl positive control of th e tape uncl er
all rulllling condition s, ~l1(l it h:lI1 clled the
tape gently. It shoulcl be poin ted out again
that this machine does not use pressure
p ads at the head a nd thus should have less
head wear tha n machines thnt do.
In sum, we would rate the Heathkit velOY
well for its peTformmlce charact erist ics
in its category, suitable for t he kit builder
with some experience. It coulcl also be appropriate fo~' the less experienced builder
with good mechanical ability. In either
case, at its price it i s an excellent bu)'.
L -20
Fig. 2 . Shure-SME ton e arm , Model 3009 Se ries 2 .
SHURE-SME TONEARM,
MODEL 3009 SERIES 2
For th e past yea r or so, the name SME
has cropped up whenever fin e tonearms
were the subj ect of conver sation. This English firm has now become associated with
Shure Brothers, a name known and respected in this country mainly as a manuf acturer of top-quality cartridges. (In
reality th e Shure people also make a very
fine a rm in th eir owu right, which we ha ve
reported in th e past.) Thus we see two excellent reputations joined and, as well shall
describe more fully, a happy marriage it is.
First a few descriptive words about the
arm. Th e Model 3009 Series 2 is essentially
the same 9-in. SME arm we h ave heard
about except that it now sports a rather
simple "bias adjuster" which compensates
for wh at we call "skating" force- t he t en dency of the a rm to move towarels the cent er of th e r ecorel and thus exert more for ce
on the wall of the groove closest to the
center. Th e cause of this "skating" force is
th e friction between stylus and r ecord in
combina tion with the offset of th e arm,
which produces a turning moment about
the vertical pivot towards the center of the
record. T he bi as adjuster applies an opposing force and it is adjustable to compensate for the stylus force.
The Shure-SME arm is one of the few
we know of which compensates for this inwa rd for ce (we can think of only three offhanel). Some people have wonder ed as to
the importa nce of this adjustment with
a rms that can track with stylus forces of
1 gr am or even less. In fact, it is our understanding th at the SME p eople were in
the doubting Thomas category until they
AUDIO
•
NOVEMBER, 1962
\
More Uses for Versatile Tarzian Tape
'7 '.
(51\
Double Your Pleasure
With an Extra ~ Inch
rains in the Living
Here's good news for owners of battery-operated tape
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"tensilized" Mylar* tape. Tape footage and available recording
time are doubled. You get 600 feet of Tarzian Tape and
one full hour of recording at 3% Lp.s.-compared to
300 feet and 30 minutes with the old-fashioned 3-inch reel.
Tape belongs at parties-to provide pre-taped entertainment,
and to record activities while they happen. If you have a
stereo machine, how about suddenly interrupting taped
background music with the sound of a freight train that
seems to be running right through the party room?
Don't forget that many people have never heard
themselves talk. Let your guests take turns recording for
later playback ... on Tarzian Tape, of course.
Tarzian's Free Booklet
Read While You Drive?
"The Care and Feeding of Tape Recorders,"
has 16 pages of additional ideas for using
and maintaining your tape recorder. Get
your copy from your tape dealer, or write to
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Tarzian Tape to capture every sound with
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tensilized Mylar-on 3, 3~, 5, and 7-inch
reels to meet every recording
requirement. The price is competitive-the quality is unchallenged.
Not really ... sometimes it's just impossible for you to give
the children a "live" reading performance. But you can
keep them happy during lengthy auto trips, or any other
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AUDIO
•
NOVEMBER, 1962
r.
65
studied the problem in their labs. The
point is, if you are going to the trouble of
producing an extremely fine tonearm, as
these people evidently have, it is importa!1t
to eliminate ~very conceivable form of dIStortion you know about--and that goes
double for stereo.
The Shure·SME Model 3009 uses knifeedge bearings to achieve the effect, and
close to the precision, of a laboratory balance. The very low friction of this type
of bearing is an important factor in the
ability of this arm to track with a stylus
force as low as a % gram with a properly
compliant cartridge. Of course these knifeedge bearings are used only in tile vertical pivots, but the horizontal pivot bear·
ings are extremely low in friction too.
comes in two sections; with both sections
on, the calibration marks indicate % ·gram
steps, the rang~ being from % to 5 gra~s;
with one sectIon removed, each step mdicates 14-gram steps and the range is
from
to 2% grams. We were unable
to check the -gram setting, but from % gram up we found the settings accurate.
The Shure·SME 3009 permitted us to
track well with the Shure M33-5 cartridge
at 1 % grams although the manufacturer
recommends 2 grams. Also we were able to
track well with another high-compliance
cartridge at 14-gram less than we had
been able to achieve in another highquality arm.
In summing up the over-all excellence of
this arm we must mention the all-stainless steel construction which makes the arm
look as well as it performs. The ShureSME arm is not inexpensive. In fact it is
one of the most expensive arms of its type
on the market; another example of the
fact that quality products exact their due
(price).
L-21
* *
SHURE STEREO CARTRIDCE,
MODEL M33-5
Fig . 3 . Shure stereo cartridge, Model
M33-5.
An interesting and very useful feature
of the Model 3009 is the built-in "dashpot" for gently lowering the arm to the
record. (For those who are not familiar
with technical English, a dashpot is a hydraulic cylinder which acts as a very gentle
brake. With this device it is possible to
lower the stylus much more gently than
the usual audiofan can manage. And raise
it too.
Aside from low bearing friction, a highquality arm should have no resonance
points, or if it does they should be well
outside the audible range and damped. We
found that tile Shure-SME arm showed a
peak at about 12 cps. Although this resonance is somewhat higher than we expected
of this arm, it was well damped by the
fibrous filler inside the arm; certainly it is
attenuated sufficiently to be ineffective in
the audible range.
One of the problems with this arm is the
ratiler large hole required for installation
which creates a good deal of difficulty if
the turntable base plate happens to be
fa irly heavy·gauge metal as ours is. On the
other hand, the advantage gained by having the extra space for optimum positioning of the arm more than offsets the inconvenience. Using the protractor provided,
the arm is set for minimum error (O-deg.)
in the inner grooves and increasing to
a maximum error (1%-deg.) at the outer
grooves. The advantage of this arrangement has been noted in various places including the pages of AUDIO. The range of
adjustment on the baseplate is 1 inch.
The plug·in shells of the 3009 will accept any standard cartridge and the plugin scheme is similar to the one used on the
Ortofon arm so that we would imagine
that the shells are interchangeable. Probably the ESL shell would fit too. The leads
f rom the shell tenninate in a four-pin
socket which mates with a four-pin plugand-harness terminated on the amplifier
end with phono plugs. The entire socket
and plug are shielded by a large metal can.
The stylus force is adjusted by means
of a small weight riding on a calibrated
bar parallel to, "ind ju.qt forward of, the
counterweight. The calibration weight
66
Recently we received a notice to the effect that Shure Brothers had been awarded
a patent for the moving-magnet cartridge
which they released in 1957. That cartridge, the now famous Ml, is the antecedent of the cartridge we are looking at
today, the M33-5, and most likely a whole
host of moving·magnet cartridges. Certainly
that first stereo cartridge from Shure was
as historic, in its way, as the stereo record.
The M33-5, although not quite as historic,
is indeed a "state of the art" device; it
contains all of the desirable advances that
Performance
It is quite obvious from Fig. 4 that the
M33-5 has an excellent frequency response
(please note that the test record used, CBS
STR-I00, uses a constant amplitude characteristic below 500 cps while the RIAA
characteristic does not; therefore the curve
below 500 cps should properly appear as a
delightfully smooth line which tilts down
instead of up). Separation is also good,
being slightly over 9 db at 13,000 cps, and
over 20 db throughout most of the range.
Perhaps the most important cha racteristic
of the M33 is the smooth ontput it produces. To our way of thinking, smooth output whether the curve is horizontal or not,
is of extremely great importance for good
sound quality. We noted that the output of
the M33-5 is high, and it is: 8 mv per
channel at a velocity of 5.5 cm/sec. For the
test we used the Shure-SME arm with the
stylus force set at 1% grams. A 47,000-ohm
load was used. The maximum recommended
stylus force is 3 grams.
It is useful to know that the very same
cartridge is available with a 0.7-mil stylus
(M33-7) rather than the 0.5·mil stylus
used on the M33·5. The stylUS assemblies
are interchangeable so that one ('an convert
from the M33-5 to the -7 quite easily. The
advantage here is that one cnn use the -5
for playing stereo records ani! the -7 for
mono LP's, thus employing the correct
stylus for each task with a single change.
Listening to the Shure M33 -5 proved to
be the best treat of all, as we might have
predicted from the smooth response curve.
We found it to be a good music reproducer and perhaps the least hum-sensitive
cartridge we have encountered in some
time. The Shure M33·5 should please a
large number of audiofans.
L-22
2. 5
-,_ ...
,
./
,
~-
~
.-'
~REIQUU)RJJr:E~- ~. ~ .....
-
- ~
1
,
~,
~
~\
·5
:0
~
~
J.
-10
_
S
o
~
~
RIGHT
---- LEFT
~
1/
-15
~
"'.
-20
~
..
1
......
I
CROSSTALK
~'
-~-
-25
20
,
., . .
-
,
... - r
100
----
•
- --
:"
•
1000
10000
20000
FREQUENCY IN CYCLES PER SECOND
Fig . 4 . Frequency response of Shure M33-5 cartridge using CBS labs STR-100 test
record .
the designers have uncovered since the Ml
was introduced. These advances include
very high vertical and lateral compliance
(20 x 10-6 cm/dyne), low stylus mass, excellent shielding against hum being induced
from ambient sources, and considerably
higher output. Of course it is too much to
expect this cartridge to be as superb as the
Ml, but it certainly is in the front rank
both in performance and sound.
AUDIO
•
NOVEMBER, 1962
Loudspeakers with long linear cone
travel have become popular because of
their ability to reproduce low frequencies
when mounted in a compact enclosure. When
stereo arrived, many people found they did not
have room for two folded horns or conventional
reflex enclosures. To solve this problem JBL de·
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%" with perfect linearity. They can be driven much
farther without damage. Mounted in a sealed enclosure
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crisp, accurate bass down to the lowest frequency on your
records. With a ducted port or passive low frequency radia·
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to the voice coil. As a result, JBL L·E transducers
reproduce the complete audio spectrum - not just
the low end - cleanly, with exemplary detail. They
provide complete, flat coverage of the presence range;
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Efficiency low frequency treble and overtones .
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AUDIO
•
NOVEMBER, 1962
67
ABOUT MUSIC
Players Between Notes-A Behind-The-Stands Glimpse
10 a .m. The orchestral player s a. re in
position. Jackets are draped over the
backs of chairs, instrument cases r est
open on the floor, and clouds of cigar and
cigarette smoke float upward toward th e
stage lights. The timpauist, his ear close to
the drum head, gently taps the skin and
t"I"Vi sts th e tuuing knobs. The oboist, (Fig .
1) a r eed pinched between his lips, sharp"
eus another, then sounds his charact eristic
barnyard cackle. The tuba player ( F i g. 2)
looks over a tricky p assage in one of the
scores to be r ehearsed. The French horn
player ( F i g. 3) squeezes a liquid valvecleaner into his instrument with an eye
dropper. The strings, fillgel'-limbering, produce a tonal swirl whose individual components might include anything f rom a
B ach Concerto to L'Histo'il'e d~£ Soldat.
All this noise suddenly becomes louder
the moment the cond ucto'r is seen entering
t he hall, a phenomenon <la nsed by last minute preparations. The cl'escendo is f ollowecl by a S'ltbi to piano as the musical
director mouuts the podium, exchanges
greetings ·with the playe rs, puts on hi s
sp ectacles, opens the score, raps his baton,
and the r ehearsal begins.
Presumably everyone should now get
clown to business. But wh at about the wind
players who enter only past the halfw ay
point of the movement, 01' the p er cussionist
whose three cymbal clashes occur at bars
390-400 ¥ These and simila rly unemployed
musicians may, of course, count bars or
wait for cues, although th ey usually find
other things to do. For the rows of music
st ands fanuing out from the podium often
conceal activities which bea r no connection
to the music in rehearsal, but which need
not affect the quality of the p erformance.
Reading is the most popular extra-musical employment. It i s a simple matter for
1
'1' I S
Fig. 1. Oboist with reed .
68
the non-player to lay a book or newsp aper
on his stand, out of the conductor's visual
range. Paperbacks are a great boon to orchestral musicians since they ar e compact
and, unlike hard covel' books, have not
been known to topple over stands. Newspapers are less easily disguised. The sheer
bulk of large-city edition s makes them unsuitable f or mounting on music stands,
although t a bloids can be thinned out and
folded to a manageable size. The N ew
Yo ric Tinnes' embonpoint, however, poses
special problems, but th ese can b e over come by extracthlg pages of most inter est.
The big r ead ers are n at urally to be
found in the wind, brass, and percussion
sections because of the intermittent nature
of their p arts. Experi enced string players,
however, t ake advantage of even short
"rest p eriods," esp ecially wh en p erforming
a work in th e standard r epertoire.
237. For this he was r eady with one of th e
few cues of his career, and his baton
whipped t he air. The percussionist, wh o
had r ecently invested heavily in th e stock
mark et, was anxiously studying the r eports
in the newspaper spread out over his ta ble,
and had missed the cue. The conductor im mediately called a halt and inquired: "Say,
what abo ut the cymbals at b a r 237 ~ " In
pl'es"tissvmo t empo, th e pl ayer fol ded. the
newspap er, dropped it to th e floor, and,
with perfect sangfroid, r eplieel: "You want
it louder, ma estro ?"
A sign on a W ashington, D . C., newsst and
warn s tbe p a ssersby that "Excessi,' e l'eading will not b e toler ated." The qui ck-thinking p er cussionist may have convinced our
dilettante conductor that he had indeed
played his part, but h er e wa s a clear case
of excessive reading.
The orchestral player's reading matter
extends from newspap er s and maga zines to
Proust, languages, electronics, and erossword puzzles. The clarinetist, for example,
whose lips are moving a s he seemingly
examines his music p a rt, may be actually
trying out a simple sentence in Russian .
Generally speaking, the first desk player
does not indulge in on-the-job r eading. Hi s
extra-curricular activity r evolves around
hi s r esponsibility as section leader, and his
own artistic car eer. The horn leader, for in st ance, might keep his players in t hei r
chairs during short breaks in order to r ehearse a tricky p assage involving intonation or rh}'thluic problems. The concel·tmast er, f 01" whom a n ew concerto h as just
been cODlJllissioned, may b e busily wor]<in g
out fingering and bowing at every chance.
Fig. 3 . Horn player lubricates valves.
Fig . 2 . Tuba player reviews the score.
Conductors ar e certainly aware that a
consider able amount of r eading is done on
t he job. Theil' attitude is r ealistic ; they
shut their eyes t o it, hoping that th e players will have the good sense to be discrete.
However, when confronted by a "fl agrant "
r eadel', they have no altern ative but to kick
up a fu ss. Sever al year s ago, a composer
of light music who occasionally indulged
in conducting, was dir ecting a r ehearsal in
New York City . His stick t echnique was
primitive, but the repertoire was of th e
famili ar "pops" variety wbi ch caused no
amdety among the musicians. The maestro
did little more than beat time, except in
th e case of one piece, which he conduct ed
with what was for him a dramatic flourish.
The work feat ured a c}'mbal clash at bar
The explosi" e growth of amateur photography ha s added a new wrinkle to the
rehearsal scene. We now find cameras
danglin g from th e necks of orchestral mu sicians who are self-appointed photo-journalist s of th eir orchestra . Unlike r eading,
special permission for this activit y has t o
be obtained f rom th e conductor an d th e
management. Some of the finest candid picttu'es of conductors aud soloists have actually b een shot from the orchestra seat s.
'rh ere is no donbt th at th e amount and
charact er of behind-the-st ands conduct
varies according to the stature and effectiveness of the man on the podium, all of
which r elat es to th e problem of discipline,
a topic f ew couductors wi h to explore in
p~~
AUDIO
~
•
NOVEMBER, 1962
... and every ounce i~ pure performance!
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Eliminates Feedback Problem-Because the new high compliance
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distortion. The "battleship" type of turntable more easily picks up
room vibrations and transmits them with greater amplitude. When a
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T·.
BAROQUE AND BACK
A Recital by the Academy of Saint Martin-In-The-Field directed by Neville Marriner. (Concerti Grossi by Corelli, Torelli,
Locatelli, "Albicastro, Handel.)
L'Oiseau-Lyre SOL 60054 stereo
Here's another of those pleasant British
groups dedicated to old music that are a
specialty .on this nominally French label,
associated with London Records (British
Decca). These concerti are played with tIle
proper "authentic" small ensemble, plus solo
group and continuo accompaniment, in a
semi-intimate style, a sound that is now utterly familiar to millions of record listeners
(and radio listeners) the world over- though
It still eludes the world's major symphony
orchestras, which will n ever understand it
anyhow. (Not until the symphony concert
turns into a Cocktail Hour MUSicale or a
Night Club Coffee Seancfr--it would take that
80rt of revolution.)
The playing itself is pleasantly musical,
sensitive a nd gentle in a British way, a bit
old-fashioned in sound. Still some of that
plop-plop-plop plodding articulation that used
to be the 'official way of playing a ll Baroque
music-not much, luckily. Enough to give the
music a somewhat heavy cast, of the sort we
used to think mandatory in Baroque music.
H eavy, but musical . .A. pleasant r ecord.
Buxtehude: Organ Music (complete).
Walter Kraft.
Vox Boxes 27, 28,29 mono
(9 LP's)
Phew! Vox's boxes aim to be comprehen sive.
I did not play all 18 sides of this super-set.
I'd like to, but p'l ease, give me a year or so.
The music is well worth it.
I'm not clear as to wIlether Vox is reissuing these; in any case, it appears that they
must have bpen recorded over a goodly stretch
of time beginning in mono days a nd hence
aren't technically suitable for new release in
the usual fashion. So much the better- for the
Vox Boxes are generally bargains at their
price.
The r eco rding is excellent, if not spectacular. I question to some extent the mike placement, which seems to me a bit too close; but
this is a minor problem, leading merely to a
certain lack of rapport between the echo or
Il veness and the sound itself. Common effect.
What is more important is Walter Kraft's
playing, which is technically skillful but musically methodical and unimaginative, lacking
in humor and sprightliness, notably in the
Buxtehude fugues with their peasant-like
tunes. Buxtehude can be better than this. But
a goodly part of him is here, nevertheless.
I'd recommend these boxes as an excellent
base, at a good price, from which one may
proceed to collect and compare other performances of the music.
•
•
The complete Buxtehude organ wor ks seem
to h ave fascinated a surprising number of recording companies, though to my knowledge
Vox's is the only "complete" set that has been
70
Try These for Baroque
Vivaldi: Four Violin Concerti. Nat han Milstein; Chamber Ensemble.
Angel S 36001 stereo
Corelli: Christmas Concerto. Tartini: Cello Concerto in D. Vivaldi:
Sinfonia in G. Hungarian Chamber
Orchestra, Tatrai.
Monitor MCS 2056 stereo
From many thousands of miles
a part, on two la bels of unlikely juxtaposition, come two splendidly styled
"Baroque" recordings, each Impeccably
played, each reflecting the very best
sort of "au then tic" performance of the
music. It is significant, I gness, that
the music is from Italy, a country
which at the time of these composers
dominated the musical world from Russia to America.
It is astonishing the w ay that
Nathan Milstein has tempered his violin tone and polished his technique to
project the extraordinary sou nd of this
performancfr--almost without vibrato,
p ure, disembodied, incredibly accurate,
beautifully phrased, perfectly blending
with the ensemble harmonies. It is
"authentic" in that this Is the only
way the music could have bpen intended-on sheer internal evidence.
The sense falls apart under the Romantic treatment of the stand'lrd violin t echnique. An amazing record and
every music lover should have it on
hand as living evidence thnt the uRual
fat, stuffy symphonic Vivaldi Is wrong
and always was. Who sald Baroque
music was thick? Not here.
By some miraculous intuition, the
distant Hungarian ensemble on Monitor's disc has found the same sort of
tone quali ty for Its similar music.
The orcheRtra is somewhat larger, the
performance a bit more conventional,
but the sound is there even so. Another
fine r ecord for the man who wants to
know what B a roque music really
sounds like.
completed. Westminster started a series, one
disc a t a time, in a sort of ultra-violet stereo
sound. The Archive Series has the beginnings of a complete Buxtehude and will no
do ubt go on to t he end sooner or la ter. The
Haydn Society launched a Danish series, of
which I got Volume 1 before the company
stopped sending them out. (That was almost
fo ur years ago.) Even Washington, a label
u sually circumspect in the number of its r eleases, launched a complete Buxtehude, with
the famous Finn Vlder~. I have Vol. II, anyhow, as of 1960.
The nicest Buxtehude to date, in my estimation, is that from the tiny Overtone company of New Haven, Conn. That's because
Luther Noss is a splendid Buxtehude organist, the organ is very line, and the recording
is very hi-Ii, though mono. How about 8 more
LP's of the same, Overtone? That'd do it.
Variations on Popular Songs by Sweelinck. E. Power Biggs, organist.
Columbia MS 6337 stereo
(mono: ML 5737)
"Eee-power" (like air power), as most organ
fanciers tend to call him, got a brand new
organ for his home base in Cambridge, Massa·
chusetts, back in 1958 and since then has
been performing on It for Columhla, instead
of on the world's old organs a ll over the place
as featured in earlier Columbia albums. T he
change, I'd say, has not been altogether
health y. There was an enthusiasm, both verbal
and musical, in Mr. Biggs' wOl'ld-wide organsampling, a s('nse of stimulation afforded by
the heady succession of marvelous Instruments, that is lacking today in the home production. In fact, Mr. Biggs has reverted to a
type of routine perfo rmance famllilt r for many
years, out of this same building on an earlier
organ, via radio and on his RCA Victor records before he shifted to Columbia.
'.rhe Sweel inck Variations are lovely. Each is
based on a popular tune, some of them British,
melodies that are a s straightforward today
as then. Each offers marvelous counterpoint
and elaboration and plenty of opportunity for
color-contrast, within the simple Ellzabethanperiod harmonies.
Mr. Biggs' trouble is not at all in registration nor in technical facility. He rips along
famously, and colo r fu lly, too. But even so, his
music is mechanical, lack ing in flex ibility and
phrasing. Mr. Biggs makes use, against all his
own best theories, of a manue ri sm that must
date from his student days among the big,
soggy Romantic-period organs of Britis h and
American churches-he plays a needless and
annoying staccato, separating each tone from
the next. On the Romantic organs it was
either this or nothing; you had to separate
the sounds If they were to be heard. On the
n ew (and old) Baroque-type or~ans, as Biggs
would be the first to say, there is no snch
n('cesRity at a ll. Why bother, then? Especially
when the mannerism contributes so un pleasan tly to a lack of phrasing and shaping of
melodic line.
XV Century Netherlands Masters. Isaac:
Music for the Court of Lorenzo the Magnificent; Obrecht: Missa Fortuna Desperata. New York Pro Musica Motet Choir
and Wind Ensemble, Greenberg.
Decca DL 79413 stereo
The New York Pro Musica, with the help
of some whopping foundation g rants an d a lot
of paying audiences, turns out old music hy
the carload. Impossible to keep up with a ll
their discs. This one, though. has special
interest In that it introduces ROme of the
Pro Musica's newly trained old-instrument
players and their strange Instrllmentsshawms, cornetti, Sackbuts. Also tb(' larger
choir of men and boys that now supplements
the solo singers.
No question that this organization has
wrench ed the whole business of "authentic"
music out of its complacency. The Pro Musica
has a- new sensation every year, born out of
solid musicology, too. Their vocal works, for
ins tance, a r e here accompaa ied by the new
weird instruments exactly as indicated in old
AUDIO
•
NOVEMBER, 1962
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•
NOVEMBER, 1962
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71
paintings, engravings, carvj ngs and what-n ot,
as well as in written accounts. No substitutes.
Right from the horses' mouths. The resultin g
sou nds are star tling and probably oug h t to be.
We mostly hear what we are used to, these
days, authentic or no, not w hat we would have
actually h eard, say, in the XV cen tury. Far
from it.
Two things seem to me not very authentic
in the Pro Musica production style. One is the
voice quality. The Pro Musica simply has a
blind spot here, for they use perfectly ordinary
vocal tones of au Italia u-opera or ch u rc hchoir sor t , quite indiscriminatel y, even in their
high-toned cou ntertenors. Good voices-bu t
strictly of tod ay. If we are to have shawms
and krummh orns, and shawm players, why not
t rain up or seek out some "au t hentic" voices
too ? By in ternal evidence in t he music, by
analogy, we cou ld easily fin d a proper tone
qual ity. It would, I suspect, sou nd like a batch
of vccal crows cawiug. That's what the
krummhorns and shawms sound like. I like
them.
Secon dl y, the Pro Musica's music is lovely
in the slow sections, bu t tends to r ace like
a batch of u oisy sports cars in t he fast parts,
dashing the mus ic in to bits and pieces on the
cu rves. Neither l ovel y nor musical, I say. Why
such a tension , why 0 violent? Must be the
atom bomb a nd people's New York nerves .
SOUND IN STEREO
Authentic Sound Effects, Vol. 1.
Elektra EKTP 7251 stereo tape
Here is Volume (Reel ) One of a sedes of
sound effects tapes in stereo and it brings up
some in teresting questions .
Soun d effects a·jscs- not tape, not stereo,
not even LP-go back '1:0 the earl y days of
broadcasting. Their use was specific enough.
Ninety per cent of it was for radio drama a nd
for radio commercials; t he rest was for "l ive"
sound effects, in stage plays both pro and
amate ur. The discs weren ' t ordinar ily found
on t he general hom e market and few of them
ever got onto a home phonograph .
Then came h i-fi-and so:uld for sound's
sake. Somethin g new hali been ac1deli and it
wasn't only low distortion and wide tona l
r ange. Sudden ly, people in ho mes' wanted
sound effects to listen to. Crazy. But they've
been getting them now for a long wh ile. Bird
songs, auto races, steam railroads, the Queen
Mary, and so on.
Now mind you , "hi-fi" sound effects fur
listening aren't at all like the old recordings.
They are louder and no isier, of course, but
mostly they are much longer. LP a llows it,
and the customers demand it-they want
enough of each sound to get t he feel of i t,
painful or joyous as t he case may be. None of
those five-second dabs, please! Definitely, the
h i-fi man's sou nd reco rd is altogeth e r a differen t affair. It's for contin uous lis t en i ng.
After a ll , the old lO-illch 78-rpm d iscs
couldn't very well feature an unbroken ha lf
hour of steam railroading, like today. Commercial sou nd effects were physicall y li mited
to short passages, as brief backg rounds, to
suggest a setting in minimum sound-terms.
Auto drives up, sto ps. Beep beep. Baby c riesonce. Bell r ings. Door opens, closes. Thunder,
one clap. Water pours from faucet, ten seconds. No sooner started than stopped, and
by this means the old r ecords managed to
cover a great deal of sound-ground. You could
thns find almost any effect you wanted- p rodded it was short.
So now we have Elektra's new tapes, hi-ft.
four-track, i n stereo, a nd the company says
they a re "idea l for theatre groups, hom emovie enthUSiasts, radio and TV stati6ns,
slide shows, ind ustrial presentations, parties,
sound buffs , and many others." Not very
g rammatical (many other whatsr) but yon
get the idea. \~That you' ll find here is strictly
the old-line type of sound effect. Dozens,
mostl y very short, just liI,e the 78-rpm discs,
in spite of hi-fi a n d stereo. They are as useful
as they al ways were, of co u rse. But few
sound buffs are going to be amused. Too short.
Too many long pauses between effects (to
facili tate locatin g) . Definitely n ot the sort
of tape you just listen to . Don't expect to add
these to you r "sound demonstrution" library;
they are strictly practical.
If so, then a coup le of cogent questions.
F irst-why on tape?
Well, tape offers hi-fi and top stereo qual ity.
People own tape recorders, too. On the other
hand, tape is very clumsy when it comes to
locating a particular spot in a h n rry. That is
of th e essence in sound -effect recording.
Otherwise, you're likel y to hit the wrong spot
at a crucial poi nt in your dramatic presen tat ion. Ins tead of th at horrendous auto crash
with the broken glass, maybe yon'll get a lou d
cat's meee-yow, or even WQ l'Se, a ca r not
crashing-j ust driving up peaceably and stopp ing. That cou ld wreck a whole year's worth
of soap opera!
So if you use tape and you'll want to cue in
a h u r r y, better cheCk your equipment wi til
script in hand before you go a ll-out. You
can't just lower a stylus onto Band Five.
Maybe what you'll wan t is an electronic
spotter li ke that currently beiug offered by
the Crown tape recorder people. SCl'llpe off a
bit of oxide before each item and the machine counts the scrapes, stopping precisely at
allY place you want. Just push the right
button. Costs money, bu t it's infallible, they
say.
Finally-why stereo? \Vell, stereo is a good
idea for eve r yth ing these days. Can't do any
harm and m ig h t be darned nsefu l. Yon 'll have
to be extl'll-ca refu l, thongh. Auto roars by,
right to left. Scr ipt calls for left-to-right. OK,
just switch channels-but don 't forget to
sw itch back for th e next item. Telep hone
rings. In the wrong speaker. Same re medyand don ' t forget it , or you'll be ha" ing telephones in the darndest places- by m istake. Or
babies gurglin g on top of red-bot stoves, doorbells ringing in the k itchen sink , dogs barking
on the mantel piece. You ncyer know where
things are going to be heard in this new
spatial stereo.
Maybe the easiest way is to switch your
tape recorder to safe-and-sound mono , like in
the old clays. Life is complicated enough as it
is. Elektrn won't mi nd.
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AUDIO
•
NOVEMBER, 1962
THESE
MOZART AND FORWARD
Mozart: Symphonies No. 33, K. 319; No.
36, K. 425 ("Linz"). English Chamber Orchest ra, Colin Da vis.
L'Oiseau-Lyre SOL 60049 stereo
1 t is a fin e thing to be able to hear these
relati vely small-scale Mozart symph onies
played as they were intended to be played, by
a " s mall" orchestra, infor mally. at fairl y close
quarters. For many years the large symphony
orchestras h a ve performed then, even with
"reduced forces, in a "big" st yle that is u n suited to their m usical meaning. Too porten tous, too g rand, too concert-like. Th ey just
do n' t go over w ell at a symphony concert,
right alongside Tchaikowsky a nd Rachmaninoff, not t o mention Beethoven and Brahms.
The ea "lier work h ere, No. 33, is par ticnla rly
nice, played ingratiat ingly, simply, with fine
phrasing and in a r elaxed fas hion in spite of
a high stand a rd of accuracy. No rushing
tempi, no virtuoso stu ff, a nd at the same time
no Germanic stodginess (such as we often find
in non -Germa n ic orchestras! ) .
I long owned Sir Thomas Beechrun's 78
ver sion of t he "Linz" symphony, complete
with lar ge orchestra and a bsu rdly sl ow temp i.
I used to think it a pretty dull work. Here,
th ings move m uch f aster -a bit of a jol t for
me at first, until I got u sed to it. But all in
all the "Linz" comes out h ere in its own best
terms. Useful.
JJ
Haydn: The Seven Last Words of
(Oratorio Version). Soloists, Vienna
e my Chorus, State Opera arch .,
che n.
Westminster WST 17006
Christ
AcadScherstereo
SPEA KERS
IN THIS ARRA Y
This solemn and sweet su ccession of seven
slow movemen ts was introdu ced on r ecord s
years ago in a mu ch s impler form , t h e version
for string quartet. The original was for orch estra alone, serving a s a set of mnsical interludes in a solem n service of sh or t sermons
on each of the seven texts. Later, Haydn
converted it to the present fo rm by a ddi ng
solo a nd choral parts, pl us on e extra instrumen tal section.
The main difficulty-eas ily by-passed on
LP-is that the whole is Slow, except t h e
brief "earthquake" mu sic at the end . I n a
church service this co uld be no problem . I n
concert, th e mu sic drags. On r ecords- you
take it a piece at a tim e. In that fashion, it
is lovely, and this is a typically mellow, rich
Austrian performance, well laid out under
Scherchen 's dir ection. He does str ange things
to other music, but in Haydn he seem s a lways
to get the best of t he sen se a n d dignity in
t he music.
Rossini: Overtures. London Symphony,
Pierino Gamba .
London CS 6204 ste reo
If memo ry,
a lways Slightly f uzzy wh en
caugh t un awares, serves me righ ther e,
P ierino Gamba was a boy-condu ctor a bit of
awh ile ago , the knee-pants sort who has to
stand up on a box to be seen. Well, you 'd
never know it f rom t his record, fo r two good
r eason s. First, London says n ary a w ord
a bou t its conductor. Ju st a l ot of stuff abo ut
Rossini. Secon d, th e mu s ic is impeccably a nd
a uthoritatively played, abou t as nicely as it
eve r can be. Fu ll of boun ce, humor , r hythm,
good phras in g and balan ce, perfect detail-work.
Five over t ures h ere, the usu al on es .
Of course (you'll muse) a fi rst-m t e orches tra cou ld play th ese pieces without a
co nducto r of any so rt, t hey a re so fa miliar .
True. But, I suggest, not wit h a bad co nductor. In s uch precision-playin g as Ro ssini requires, any conductor less t ha n ex cellen t becomes a monkey wrench in h is own performance. Wit hout h im-fine. With him , more
tha n a likely chaos and confusion.
So Mr. Gamba mu st be goo d.
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through an N-105 LC cro ssover network. Woofer roll-off is at 400 cycles;
mid-range tweeter crossover is at 1,500 cycles. Useful frequency response
is 35 to 20,000 cycle s; suggested amplifier power is 30 watts minimum.
The components are available as a panel mounted system for built-in
in sta ll ation (Model P-4000P). As the Model B-4000, the components are
housed in an 8 cu. ft. volume infinite type baffle. The enclosure is handsomely styl ed in hand-rubbed fini shes on- Genuine Walnut, Mahogany or
Cherry. Used in matched pa irs for stereo, the Symphony No. 1 reflects
th e true depth and breadth of a symphonic performance in your home.
See yo ur authorized dealer or write fo r details.
Brahms: Symphony No.1. Philharmo n ic
arch ., Giulini .
Angel S 35835 stereo
The Very Best in Music
I picked t his on e out with som e t r epidation
- Italian ideas of Brahms are often rather
BOX 1166, DARIEN , CONNECTICUT.
AUDIO
•
NOVEMBER, 1962
73
startling. B rahms was abou t as un-Italian as
they come, u p in No r th Germany.
Well, the P h llharmonia, at least, is perfectly
able to playa fine Brahms F irst. It does, here.
It has no important eccentricities, sticks
nicely to comfor table tempi and accepts
Brahms' musical fabric in its own terms withou t strain. After a good long listen, I find
only one mlld complaint: it isn't really a very
inspired performance. Lovely sound, even so.
Curtain Up! Sousa Favorites. Eastman
Wind En s., Fennell.
Curta in Up! Orchestral March Favorites.
Asso rted Orchs., conductors.
Mercury SR 9029)-92 stereo
(also others)
~~
Oaewbora
big brother, doest thou leel
more competent than. to up·
hold the Ilawless reputation
01 !tOSS STEREOPHONES ~~
One of the blessings of tape, sometimes
not entirely a blessing, is the way one can
cut the same taped musical pie in any numbpr of directions, revamping for new sales.
I can only mention these two in lIIercury's
np'W series, presumably open-<!nded, of excerpts from t he l\ler cu ry cata lo;!ue reissued
in new groupings under new healUngs.
The Sousa mater ial as per formpd at Eastman is absolutely first-rate, no watter how
you slice it. You'll begin to see in t he.e recordings what a superb composer this Sousa was,
in h is own area. Best marches ever written.
Perhaps even better In their way than, say,
the Strauss waltzes.
The orchestral marches are so varied I
can' t take space to describe them- numerous
composers, several performing groups too , out
of Mercury's artistic stable. Better look the
whole ser ies over to see whether these packages suit your needs.
Bernstein Conducts Copland-EI Salon
Mexico; Appalachian Spring; Dance from
"Music for t he Theatre." New York Philharmonic, Bernstein.
Columbia MS 6355 stere o
(mono: ML 5755)
~~ 0 little brother,
thy sound is as sharp & clear as the
day KOSS invented thee but when
it comes to the tough professional
jobs, give thee way to my shining
armour ~.,
)toss
2227
74
NORTH
3 1 st
ELECTRONICS
STRE E T.
INC .
M IL WAUKEE, W I SCONSIN
Perfect. What else? Bernstein has been one
of Copland's most devoted and perceptive followers in his own music, going fu r ther in the
sallle direction that Coplanl\ himself pioneered,
t he usp of a popular AmericUll-style idiom for
American music. Their minds in this respect
run on a hearteningly similar track, though
their careers have been different.
In Europe and often hereabouts too, Copland's scores get a too-classicn l tren tment.
The jazzy, fo lksy elements are uncomfortable
for pi en ty of "classical" conductors and not
a few performing musicians as well. These
character istic Copland sounds, the refore, tend
to be played down, weakened, apologized-for;
or they are given the Brahms-and-Wagner
treatment, buried under an elegantly classical
exterior. Not so iu the Bernstein version!
Enou gh said.
Milhaud: La Creation du Monde; Suite
Provenc;ale. Boston Symphony, Munch .
RCA Victor LDS 2625 stereo
About time somebody did another "Creation"-this short jazz-influenced score was
one of the very first of its type, well before
Gershwin and Copland, back in 1923. It
sh ocked the musical world then, of cou r se, but
it doesn't now. In fact, this is a rather tame
reco l'ding of music that once seemed outrageous. Maybe it's inevitable.
I have a priceless old blue-shellac 78
Columbia recording of the same music, performer! back in the early thirties when the
stuff was still pretty far-out. It soun ds that
way, and it should. I n contrast, the suave
Charles Munch and his suave Bostonians play
the early jazz as though it were so much
Edward !I1acDowell. It should be closer , d r ier,
too, more in a theatre style, ideally speaking.
Not much the Boston Synphony can do about
that, I guess.
The la t er "Suite Pro ven~ale" , of 1936, was
der ived from some Seville t heatr e music Milhaud wrote, based on themes f rom an "ear ly"
Provcn~al composer, And r~ Campra. Accordingly, a ll commentators, in cluding RCA Victor's, expatiate about the sunny Proven~al
country as portrayed in the music, quite overlooking a much more obvious effect in the
actu al sound- a "Bach-like" Baroque, In
AUDIO
•
NOVEMBER, 1962
modern terms, ou t of the turn of the EIghteenth century. Milhaud's typical "polytonnlity" is merely a heap of genial dissonance,
two chords at once, added on top of the very
Bach-like rhythms and harmonies of the basic
music. Reminds me a bit of Stravinsky's
"Pulclnella" music, based on the E ighteenth
century Pergolesi.
This Is a Soria Series release and so, for
a dollar more, you get the usual gorgeous
bookful of reproductions In color and monochrome, plus essays and comment. Skira did
the prin ting.
M usic of Edgar Varese, Vol. 2: Arcana;
Deserts; Offrandes. Dona Precht, soprano; Col umb ia Symphony, Cra f t.
Columbia M S 6362 stereo
(mono: ML 576 2)
Columbia continues here the over-all documentation of the old man who has, at last,
been recognized as the Beethoven of the
avante-garde composers, the grandaddy of the
MU8i(jue Oonorete and computer school of
compo~ltion. Here you have his huge "Arcana,"
for l~O orch~stral musicians, first produced
by Stokowski and the Philadelphia Orchestra
back in 1927; you have Deserts, Varese's first
big tape piece, alternating two-channel factory-noise talle sound with a live small orchestra for a good half hour, tape-assembled in
1954 on French equipment. Big music, auy
way you listen. Then the re are, to fill out,
the two strange solo songs called "Offrandes"
(Offerings), with small orchestra, dating from
1922.
It's an exciting record-and I'm glad to see
that the technical deficiencies of the original
"Deserts" sound on tape have been tLxed up,
notably the severe tape hiss that marred the
early "live" performances on stereo Ampexcs.
Extraordinary how the factory noises and the
Instrumen tal "U ve" music tie in together,
sound aUke! "Arcana" was a big thing at the
Philharmonic last year and this is an offshoot-performance. You never heard anything
like It, and never will.
Varese, you see, is one of the few "radical"
composers in tape and assorted sound-effects,
who Is a top musician, trained, skillful, familiar with all the " greats" of the last half
century. He Is one of them. Stravinsky writes
(or dictates) the extended comment on Varese
that appears on the record jacket. You can
take Varese as an authentic big man, and you
can hear It, I think, in the music. It's noisy
and astonishingly "different"-but It sounds
wl~ an authority, a sophistication, that runs
rings about the others in the field.
I continue to be sorry that all of Varese's
music Is entrusted to Robert Craft's somewhat chilly di rection. Varese is such a hearty,
healthy Frenchman! But better this, and
Columbia's willing cooperation in an expensive venture, thun no Varese at all. That's
the way It used to be, more or less.
P. S. Until Columbia got hoM of him,
Varese spelled his nume with a d. Edgard. I
guess Columbia persuaded him to change, If
only to plucate the proofreaders who kept on
taking that offending d out of their copy. It
cou!cln't be right. (But it was.)
IE
Rockford Acoustical Cabinetry
DESIGNED BY ACOUSTICAL ENGINEERS
MADE BY JOURNEYMAN CABINETMAKERS
Rockford Cabinetry is made fo r Custom Hi-Fidelity, and to grace the
homes of people who have Hi-Fidelity equipment. It is not just a place to
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Acoustically-e ngineered and furniture-crafted of selected woods, this
fine furniture is priced much lower th an you would expect for such exception al styli ng and workmansh ip. Equipmen t cabinet and free-sta nding speaker enclosu res may be placed togethe r or separate, as you
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DAN I SH MODERN CABINET ENSEMBLE
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tape reco r ders. I nside dimensions: 140/8" x 17 114" x 6%"
deep. l ower ri gh t compartment has space fo r 100 lP
reco rds. Upper l eft compartm ent h as b lank face p a n el fo r
custom install ation of a m plifie r a n d/or p r ea mpli f ie r a n d tu nor.
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I N SIDE SPEAKER ENCLOSURE. In divid u al spea ker e nclosures
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G IVE
For inf ormation see
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or writ e today for
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Dealer inqu iri es invited .
Prices slightly highe r
West and South
AUDIO
•
NOVEMBER, 1962
75
at tou rist rates. On ly fiv e years ago, t h e bass
range oE the opening Illast of a steam hi p
whi stle wou ld have been somewhat of nn
aud io event.
JAZZ
and
all
that
?-------------------------------CHARLES A. ROBERTSON
STEREO
Odetta: Sometimes I Feel Like Cryin'
RCA Victor Stereo LSP2573
Odetta: Odetta And The Blues
Riverside Stereo RLP9417
All t h e confusion of movin g from one r ecord company to another t urn s out to be just
wba t Odetta ueeded to put ove r one 0[ h er pet
projects. While r ega rded prima rily as a foIl'
singe r, s he varied program s from t h e time of
her first appearan ce on records with the in clusion of one or more early bl ues classics.
To give this part of h er repertoire a n authent ic touch , she broad ens ber usual sty le and
adopts the deeper, pulsating tones of th e late
Bessie Smith. So close is the resemblance to
the Empress of t h e Blues during tbe prime
years tbat Odetta's name figured prominen tly
in talk a bout a film ed history of h er reign.
Tbe concurrent release of two a lbums entirely
devo ted to the blues certainly looks like the
st art of a plot to nail down th e principal role.
Odetta's credentials are in the best shape of
any presented s o far, but t h e dec ision makers
in Hollywood may run t ru e to fo rm a nd fil e
t hem away und er t he sec ti on set as id e for
can didates to play the life of Billy Holiday.
No longer under contract to Vanf,'Uard, the
s inger is now sign ed exclu s ively with RCA
Victor, but fortunately the shift was made ill
a hop, skip, an d jump. Keeping a promise to
s ing with a small hand on a Riversid e date
introduced her to Dick 'Vellstood, who ser ves
as pianist a nd a rra nger on both a lbum s. Work
on h er first Victor release ha d a lready begun
last April when the River side ses ·ion s were
held, with Wellstood ill chal·ge of a sextet
consisting of B uck Clayton, trumpet, Vic
Dickenson, trombone, H erb Hall, clarinet,
Ahmed Abdul-Malik, bass, and drumm er Shep
Shepherd. So well did everyone get along
t hat the singer scrapped plans to use a more
modern group at Victo r a nd insisted on having
Wellstood direct the accompanying force.
Wellstood works regula rly in t he crew Wild
Bill Davison leads a t Nick's in Greenwich
Village, and his a bility as a solo pia nis t is
known to the patrons of Eddie Condon's East
Side spot . Represented as a leader on a Prestige LP, another will be forthcomin g from
Rivers ide because of his excellent s upporting
role behind Odetta. Not espeCiall y act ive as
an accompa nist before, he provides the sort
of backing that both guides t he Singer along
and allows a great deal of freedom. The arranging chores were r educed to a bare minimum by r esear ch into Riverside's a rchives of
early blues, followed by sess ions of joint listening to the titles selected. From th a t point
on, according to Wellstood, it was simply a
matter of " picking the right guys and lettin g
them do what they wanted to do."
One co mment passed around at both dates
was a complimenta ry "she s ings ju s t lUte
Bessie Smith only better, " and it went unchall enged by musicians who heard the original in
person. The knack of singing better t ha n t he
early Queens of the Bl ues is no great accomplis hment, as few, if any, ever took voice
iessons. Ins t ead, they learn ed before a n a udience each n ight and put harsh experience to
work in a style ditli cult to emU late. Odettn
studied the classics and toyed with the idea
of trying t he concert stage before deciding 011
a career in folk mus ic. While giving a good
account of herself in prev ious bouts wi t h th e
blues, some stiffness and the det a ch ed air of
the trained si.nge r impaired h er efforts. Going
into action with gen uine jazz players makes
an enormou s differen ce, and only the bares t
76
vestige of for mal co nst rai nt r emain s. The
next t ime E ileen Farrell decides to indulge i n
a blu es album, she ha d better inv ite the
Messrs. 'Vellstood, Clayton, and Dick enson
a long.
B eca use t he ext ra voice of Sonny T erry's
h a rmoni ca adds more of a co untry flavor, t he
Vic tor release probably hold s grea tel' appea l
fo r Odetta's large a nd faithfu l f olk a udience.
Al so on h an d as s ubstitu tes a re B uste r Bailey,
whose cla ri net graced several Bessie Sm ith
reco rdings, and drumm er Panama Francis.
Not only are Bessie's majestic tones recreated
in both cases, bu t the wild aban don of a
second S mith girl, Mamie, lives again, al ong
with the individ ual styles of Mama Yancey,
Ma Rainey, a nd Ida Cox. Jazz fan ciers who
a re un co nvinced it can be done should start
with the Riverside set, and not a few will
echo Wellstood's r emark, "I hadn 't rea lly had
a cha n ce to hear h er sing any of these things
before. I didn't think anybody could live up to
the origin als, but 100W• . • • "
Folk en thu s iasts dismayed at t h e inroads
of big busin ess into thei r dom ain can tal<e
some consolation f rom the a mOUD t of you th
talent drawn into the fo ld by the pros pects of
solid booking. If Odetta had started out in a
diffet·ent day and age, she might have r each ed
to concert stage or tu rned all her attention
to the blues.
Johnny Gregory: TV Thriller Themes
Philips Stereo PHS600-027
Geraldo : Cruise Along-Dance Along
RCA Camden Stereo CAS720
Although in terna t ional telev ision is now a
r eali ty, it will be a long tim e before the Telstar brin gs B ri tish private-eyes and society
dance bands to hom e scree ns in this country
on a regula r basis. For those un a ble to awai t
the great day patiently, t his shipment
from overseas offers an h our or so of dancing
pleasure to while away the tim e. Johnny
Gregory's idea of cr im e detection i s to pit a
fu ll-sized swing band a~a in st twenty strin gs,
twelve voices, and n trio of Latin percuss ionists in a ster eo spectacular. Hot pursui t b)'
t he ba nd sleu t hs keeps the st rings from lagging and never allows the vocalists to overstay their welcome. Six themes are completing
a round tri p, including such fearless adventurers as Perry MaBon, Johnny Staccato, and
M Squad. Viewers on t hese shor es are already
famili a r witb on e or two of the v isiting contingent, es pecially Taranteno Rojas' SucuSucu, the currently popular theme from "To p
Secret." Most formidable of th e strangers to
arrive a re Johnny Danlnvorth 's The Avenyers,
an d the sini s ter Echo Four-Two. Th e evidence
not only indicates that Gregory and countrymen have crime under con t rol, but most
stereo problems are also well in h and, as
demonstrated by the eerie muted trumpet on
Ghost Squad.
Geraldo now bolds the title of musical director of t h e Cun a rd fl eet, a position which
by any cri terion assures t he gen uinesness of
thi s shipboard serenade. The or chestral s tyle
is much tbe same as when be headed one of
London 's top society ba nds, an d the various
medleys include a double h elping of that
purely British institution the quick step.
Tucked away among in terludes devoted to
mambo, fox trot, cha cha cha and old fnshioned waltz i s one of the sauvest and most
melodic version s of the Twist yet con trived.
After all, an y E nglishman should be able to
twist in a raging sea with a glass of champagne in one hand. The a lbum Is thoroughly
fi rs t-Class, but a ticket to step on board sells
Stan Getz ·and Charlie Byrd: Jazz Samba
Verve VSTC276 (4-track UST tape)
Afte r failing to m a l,e much head way wh en
introd uced ill this country a year or so ago, a
n ew Brazili a n dance music known as b088a
nova jumped to national promin en ce when
just a bout e,·ery radio sta tion sudden I)"
started to feature a compell ing t h eme f rom
this a lbum. Bearing the strange title Desojinallo, it was written by An tonio Carlos
Jobim , a collaborator on the film sco re to
"Black Or pheus." The vel vety tenor -sax
sound s of Stan Getz and t he s ubtle g ui tar
rhythm s of Ch a rlie Byrd began to eme rge
from all pa rts of th e broadcast world, even
pl aces where a jazz r ecord was last heard
from back in the swi ng era. Except on a few
enligh ten ed FM station s playing t h e LP, the
version used is a s bor tened 45 rpm extmct
f!"O m the album. All of which tends to increase the valu e oE the four-tra ck ste reo tape
as demon st ra t ion material. Even th e m ost
unc ritical will be able to discern immediately
t he g reat difference betw een what thei r ears
a re accustomed to and h earing the tereo tape
pla yed on good equipment. Th e contl"Ust should
prove to be very effective at audio shows,
dealer sho wroo ms, a nd any place else wb ere
tape components are sh own off.
Because of the sextet's instrumentation a nd
the stereo pOSitions of the soloists, this part icula r tape is highly r espo nsive to control
settin gs, enabling home li stener s to di splay
the fl exib ility of t h eir setups to visiting au d iofans. Not only can t he relative volume of t he
two featured soloists be altered at wilI, but
the bala nce between the principals and the
rh ythm section can be a dju sted to suit various
t as t es. Rather t ban locating a single setting
that so un ds right, the probl em is one of seein g
how many plea s ing va riations can be worked
ou t. 'l.'he con trols ca n a lso be used to touch u p
the tonal texture of each soloist independent
of the other, a nd a check of h ow mu ch tampering the tenor sax w ill wit h stand an d not become h arsh or thin should settle t h e qu estion
of why Getz continu es to win polls. It s hou ld
a lso be proof enough of t h e theory that t he
engin eer who equ a li zes the master tape or
cuts the fi ua l master mu st know how eve ryo ne
so unded in t h e studio. An idea l co nditi on
matches the natural sound of the liv e mu sicia n s when the con t r ols are se t flat , a nd t h is
tape comes as close to perfection a s a ny.
In fact, one of t he most enjoyable exptriences of the past few years has been to wi tn ess t he steady improvemen t in the quality
of Verve's produ ct. Once notoriou s for Slipshod so und, the la bel has pulled abreast ot
t he field, and this tape belongs righ t in the
top rank. The session took place last February
in Pie rce Hall at All Souls Unitarian Church ,
Washington, D. C., with E d Green at the control co nsole. The a uditorium adds app reciably
to the over-all effect, and ample space is allotted to t he a ugmented rhythm team of Keter
Betts, bass, drummer s Buddy Deppenschmidt
a nd Bill Reich enbach, with youn ge r brother
Gene Byrd a lternating on bass and gu ita r.
Every owner of fou r-track playback equipmen t should ma ke a n effort to ge t hold of thi s
tape, either by outright purchase or through
hints pointed at t he holiday season.
Lalo Schifrin : Bossa Nova
Audio Fidelity Stereo AFSD5981
As several compose l·s of bossa nOVa. also are
working gu itarists a nd some groups employ
no less than two gui ta r player s, it wou ld seem
t hat th e instrument is essential to proper
perfo rm a nce of the latest import from Brazil.
By t he same token, the very newn ess of t he
music may preclude a ny set rules as yet about
th e mod e of rhythmic propulsion. If so, Lalo
Schifr in has fas hioned arrangemen ts tha t
dem oli sh both con tentions a lmost as soon a
t h e program gets underway.
First, the Argentine pianis t decides to a ugment his r egula r companions from Dizzy
Gillespie'S qnintet with only two percussionists, dispensing with the guita r . Second,
everyone in the rhythm section takes turns at
in ser ting g nita rlike effects whenever an openin g appears, so the guitar, in spirit at least,
must be a n ecessa ry adjunct. The way in
AUDIO
•
NOVEMBER, 1962
Marvelous
hi-fi
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..
New!
<
12-inch Coaxial Speaker
PAX-30G
We are proud to announce marketing of a new COAXIAL SPEAKER
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Voice Coil Impedance: 16 ohms
Resonant Frequency: 30 - 50 cps
Frequency Range:
35 - 18,000 cps
Maximum Power
Input: 30 watts
Power Input:
20 watts
Sensitivity:
102 db / watt
Crossover Frequency: 3,000 cps
Total Flux : Woofer; 123,000 maxwell
Tweeter; 21 ,000 maxwell
Flux Density:
Woofer; 10,000 gauss
Tweeter; 9,000 gauss
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Superb Performance
and Inexpensive New
IO-inch 2-way Speaker
Exciting New 8-inch
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PAX-20G
PAX-25B
Voice Coil Imped a nce: 16 ohms
Resonant Frequency: 40- 60 cps
Frequency Ran g e:
35- 20,000 cps
Ma x imum Power Input: 20 watts
Power Input:
15watts
Sensitivity:
102 db/ watt
Crossover Frequency: 3.000 cps
Qo :
0.7
Magnet Weight:
Woofer; 12.80z
Tweeter ;
3.9 0z
Total Flux:
Woofer; 105,000 ma x well
17.000 maxwell
Tweeter;
Flux Density:
Woofer; 10,000 gauss
Tweeter; 11 ,000 g auss
Vo ice Coil Impedance: 8 or 16 ohms
Resonant Frequency :
50- 70 cps
Frequency Ran g e:
40- 20,000 cps
Max imum Power Input: 15 w atts
Sen sitivity:
102 db/ watt
Crossover Frequency :
3,000 cps
Total Flu x:
Woofer;
Tweeter;
62,500 maxwell
14,000 maxwell
Flux Density
Woofer;
Tweeter;
10,000 gauss
9,000 gauss
PlIINEER ELECTRONIC CORPORATION
PIONEER
AUDIO
•
NOVEMBER, 1962
5 Otowacho 6·chome, Bunkyo·ku, Tokyo, Japan
Distributors: Canada . Importhouse of Canada, 2939 Eglinton Ave. E., Scarboro, Ont,
Singapore & Malaya _ Hwee Seng & Co., 259 Beach Road, Singapore J
77
which the players transfer the assignment
from one to the other, tossing the ball around
In stereo like a pennant-winning baseball
team covering the bases, and the ingenious
methods of carrying it out contribute greatly
to the enjoyment of the recording. Extra accents may come sizzling from the cymbals of
Rudy CoIlins, or bounce off the strings of
Chris White's bass. Brazilian drummer Jose
Paulo respouds on the panderlo, a native tambourine capable of tinkling softly or rising to
swift crescendos. Jack Del Rio, . another expert
from the Argentine and member of Xavier
Cugat's orcheRtra, manipulates the cabaca, a
gourd with a loose covering of beads.
Schifrin's piano style is another good reason for his doing without a guitarist, as it
ranges far and wide. Known for an allegiance
to modern jazz since arriving in this country,
the pianist operates under no such restrictions
when surveying Latin music. His explorations
probably go back further in history than the
famed "Spanish tin~e" of J elly Roll Morton,
and some of his findings may antedate jazz by
a century or more. A composite of various cultures and periods, his playing is highly personal and flows best when unimpeded.
Co-worker Leo Wright never gets In the
way a nd strikes a happy medium between the
saxophone styles of the other leadi ng jazz
exponents of lJossa nova, Stan Getz and Sonny
Rollins. Occasional solos on flute also give
him the extra advantage of exploitin g the lyrical quaIitities of the exotic melodies to the
utmost. At a time when a lot of misinformation is being printed about the origins of lJo88a
nova. Joao Tazajara's notes shed authentic
Ilght on the s ub.iect. The recording is equally
luminou s, and it will shine brilliantly at audio
shows this season.
Lou Rawls: Sings Stormy Monday
Capitol Stereo ST1714
H. B. Barnum: Everybody Loves H. 8.
RCA Victor Stereo LSP2553
Some inventive soul should think up a nnme
for the new crop of singers, especially those
who trained in gospel groups, as they seldom
VIENNA
fit any single category. They flit from urban
to country blues, from rock and roll to the
twist, from jazz to pops, or mix several styles
together at once. Many try to emu late Ray
Charles, others strive to be as sophisticated
as Jon Hendricks, but they all continue to
draw inspiration from gospel sounds and
rhythms. Among the latest to arrive are Lou
Rawls and H. B. Barnum , two lu sty-voiced
passengers who descended from the gospel
train In Los Angeles a nd began to branch out
In various directions.
Rawls crossed paths with Les McCann, Ltd.,
and the encounter was mutually rewa rding
enough for them to get to~ether again on the
blues for the singer's debut album . Most titles
. selected are known from one particular version gpneraIly considered to be the best ever
recorded. Instead of takiug these performances
as model s, Rawls picks difleren t tempos, looks
for distinctive phrasing, and wraps everything
up in an individual styling. Nothing will ever
displace Billy Holiday's own God Ble88 The
Child, or Leroy Carr's original recording of
In The Evening When Th e Sun Goes Down.
Formerly a fea tured soloist with the Pilgrim
Travelers, Rawls possesses a formidable set of
vocal chords and knows how to bend a note
in any direction. What he needs to do next is
go his own complete way with original material,: written either by himself or during some
futu're collaboration with the McCann firm
of Leroy Vinnegar, bass, and drummer ROil
Jefferson.
H . B. Barnum ranges over more territory
than a dozen other singers without spreading
his talent too thin. As varied and extensive as
this program is, it bypasses his composing
activities, gospel singing, and the ability to
conduct and play many instruments. Barnum
merely acts as arranger and pianist, and
interprets such Widely-separated works as
Good Rockin' Tonight, alld Thelonious Monk's
'Round Midnight. Peggy Lee's prior claim is
no deterrent to his bursting forth on I'm
Going Pishin', becoming one of tbe few males
to bring the tune to net successfully. Even
with wild scatting on Wham Re Bop Boom
Bam, honky-tonk abandon on Old Piano Plays
The Blue8, and the quiet reserve of ai.gi, one
©®@
Now AKG's C·SO Miniature Condenser
Microphone System is travelling allclasses everywhere with the B-SO
Transistorized Power Supply.
Time was when a con.denser mike was
studio-bound. But AKG has liberated
this highest-class microphone from
the AC outlet. 8-S0 is at home wherever needed. Slung smartly over the
shoulder it weighs less than many a
telephoto lens, and includes space
for the microphone and cables.
C-SO/B-SO's versatility is guaranteed
by the quick change-over from cardioid
to omni capsule. In seconds you can
get the "musici," the pigeons alone,
or the atmosphere of the whole Piazza.
album is wholly inadequate to contain all of
Barnum.
Sonny Rollins: What's New?
RCA Victor Stereo LSP2572
The obvious nnswer to the qu estio n posed
by the album title is the Brazilian b08sa nova
featured throughout, but hearty disagreement
is apt to be felt by more than one RolIlns
follower. To them the real innovation is undoubtedly the pairing of theiT h eTo' s ten or sax
with a choral group, even though it appears
only on one number. They may forgive the intrus ion because it takes place during a Jimmy
Jones arrangement of Brown8kin Gi"l, one of
several tunes that RoIllns originally conceived
as calypsos. They need only point to the close
relationship between the two versions to prove
that Rollins anticipated a trend and was well
on the way to Rio several years ago. As far
at least as the Virgin Islands, where most of
hi s calypso ideas were born.
The muscular Rollin s approach often causes
lJo8sa nova to recede in to the background as
jazz takes over a lmost entirely, posing the
question of what really is new. Mixtures of
jazz and Latin rhythms are either impressioni stic sketches or fresh jazz works on a novel
base. As the latter method is the one favored
by Rollins and his partner, the guitarist Jim
Hall, It seems only proper to call the results
samba jazz. Instead of rushing out to cash
in on something because of current popularity,
Rollins engages in a valid and logical extension of his previous work. He even remembers
to include a forgotten movie theme, The Night
Has a Thou8and Eye8, and tests his resourcefulness as improvisor by inviting a duel with
Candido on conga drums. Hall, who played
.b088a nova in native surroundings while touring South America with EIla Fitzgerald, holds
up his end of the bargain on If Ever I Would
Le(tVe You, indicating that t he next new thing
could be a Latin version of the complete
"Camelot" score. Extra percussion aids regular quartet members Bob Cranshaw, bass, and
Ben Riley, drums, In ·filIlng out the full dimensions of the stereo stage.
.l!G
WORLD TRAVELER, ALL CLASSES
If you make ethnic recordings, or
sound tracks, or background music for
business or pleasure - make sure
C·SO/ B-SO is entered in your passport.
Its studio condenser quality makes a
Tourist-Class recorder sound like First!
No other studio-quality condenser mike
is so small, so light, so travel-wise, so
inexpensive. The mike, with cable and
power supply, fit in a leather case
smaller than 3 x 4 x 6 inches: On a
neckstrap you have no baggage burden. CoSO mike, B-SO Power Supply,
L-SO Charger, $259.50.
For data and name of the AKG dealer
nearest you, write V. J. Skee at Electronic Applications, Inc., Wilton, Connecticut. Or phone 203-P02-5537 (TWX
WILT 426).
(In Canada, George McCurdy, Radio Industries Ltd., 22 Front Street West, Toronto).
78
AUDIO
•
NOVEMBER, 1962:
LETTERS
(from page 6)
SIR:
It was gratifying to see in the article
"A condenser microphone mixer," (October, 1962), that some of the problems of
the compatibility between European condenser microphones and American speech
input systems are receiving the attention
they deserve. There is, however, one area,
that of proper impedance matching between the microphone output t ransformer
and the preamplifier input transformer,
that needs further cla rification.
The amplifier in all professional condenser microphones is in itself basically an
impedance-matching device; it converts
the extremely high diaphra gm-to-grid impedance ( approximately 180 megohms) to
a balanced low-impedance line suitable for
long cable runs. It is by nature a voltage
amplifier and is, therefore, incapable of
any power input. The impedance that is
listed in the European specifications, usually either 200 or 50 ohms, is the source
impedance looking back into the microphone output transformer. If the transformer load is improper, it will reflect back
into the plate circuit of the tube and shift
the operating point to a non-linear portion
of the curve. This transformer should never
look into an impedance less than 5 times
the source value. Since American input
transformers do not have 100-ohm strapping, these microphones can never be operated with a 200-ohm source impedance.
They should always be strapped for the 50ohm impedance.
The problem of overload of the console
preamplifier and the internal microphone
amplifier due to close miking techniques
has only one satisfactory solution. This is
an integral atteuuator in the microphone
itself between the capsule and the preamplifier grid. While p adding of the microphone line at the console input will prevent
overload after this point, only the above
mentioned type of attenuator will protect
the microphone itself.
ALBERT B. GRUN DY
International Electroacoustics, Inc.
333 Sixth Avenue
New York 14, New York
The Author Agrees
SIR:
The illustrations regarding input terminations for my mixer design describe'd in
the October issue of AUDIO were in error;
there should have been only one schematic
(rather than two) with the source impedance being 50 ohms rather than 200
ohms. This was my error, and since a correction must be made (microphone-amplifier distortion will occur), I also would like
to expand on the input requirements for
my design: 1. The microphone, with a
source impedance of 50 ohms should look
into a load of at least 5 times this value,
or 250 ohms. 2. The mixer input impedance
is lOOk ohms. These two conditions indicate, ideally, a transformer with a primary
of 250 ohms and a secondary of lOOk ohms.
The transformer used (Triad 3417150 ohms input, secondary loaded with
lOOk) reflected approximately 200 ohms to
the mike (50-ohm source) and, therefore,
tests were conducted to ascertain any ill
effects from loading the mike some 20 per
cent more than recommended. None was
observed.
For those who might be concerned about
the frequency response of the transformer
when fed from a source lower than the
nominal input (50 ohms into 200 ohms) the
response is flat from 20 to 20,000 cps
AUDIO
•
NOVEMBER, 1962
This is the Schober Consolette
Model with two full 61-note
keyboards, 17 pedals and 22 individual
stops. It is comparable to finished
organs selling from $1800 to $2500.
You 'll love the rich, thrilling tone of a
Schober Electronic Organ, and you'll
love the price, too-starting as low as
$550. Whichever Schober Organ you
prefer- there are three brilliant models
to choose from-you'll happily find it's
only half the price of a comparable,
ready-made organ sold in a store. In
fact, many people who could well afford
to buy any organ , have chosen to build
a Schober Organ simply because they
prefer it musically! You get a full-size
organ on which you can play classical
and popular music. Beautiful handrubbed cabinet . . . magnificent sound!
And you don't have to be an electronic
genius to build your own Schober Organ.
The clear, concise, step-by-step instructions make it realistically simple, even
it you' ve never touched a soldering iron!
THE
:JJcIt();Wt (j)~
Assemble it gradually if you wish. We'll
send each kit as needed. That way you.
spend only a small amount of money at
a time-for example, just $18.94 to start.
Or you can order all the components of
yC!)ur organ to be sent at once, and assemble it in as little as 50 hours!
Even a beginner can quickly learn to play
a Schober Organ. You'll soon discover a
whole new world of music, and endless
hours of pleasure. Unquestionably, this
organ is the king of instruments!
We are so proud of our organs we've
made a 10" Hi-Fi demonstration record
we'd like you to hear. Write to The
Schober Organ Corporation, 43 West
61st Street, New York 23, N. Y. for your
copy. The initial cost of the record is $2
but this will be refunded when you send
for your first organ building kit.
MAIL THIS
CORPORATION
I,
43 West 61st Street, New York 23, N. Y.
IN CANADA: Associated Music Services
216 Alverna Road
Richmond Hill, Onta rio
IN AUSTRALIA: The Electronic Organ Co .
(Australia)
II C adow Street
Pymble, N. S. W .
IN UNITED Burge Electronics Limited
Industrial Estate
KINGDOM: Greycaines
Bushey Mill Lane, Watford
Hertfordshire, England
I
II
I
COUPON
T:-s::e~g:-:o:-
TODAV
-1I
Dept. : : 43 West 61st Street
New York 23, N. Y.
0 Please send me FREE booklet and other liter·
ature on the Schober Organ.
0 Please send me the Hi·Fi demonstration rec·
ord . I enclose $2 which is refundable when
I order my first kit.
Name ____________________________
Address
LC~ ___ ~~s::-==
I
J
79
within + 0.75 db, - 0 db. The curve shows a
gradual rise reaching a maximum at approximately 18kc (+ 0.75 db ) and is + 0.3 db
at 20,000 cps. Lowering the source input to
approximately 20 ohms causes a l'ise of
+ 1.2 db.
A better choi ce of input transformer
recommended for those who might like to
construct this unit (I had some 3417
transformers on hand ) is the T ria d HS-3.
Wh en terminated at the 250-ohm tap (with
lOOk loaded secondary), it reflects approximately 215 ohms to the mike and exhibits
an improved frequency r esponse for a
source impedance of 50 ohms. It is flat
from 20 to 20,000 cps within + 0.3 db, - 0
db, the peak in r esponse of 0.3 db occurring
at approximately 15.5 kc. Lowering the
source impedance to approximately 20 ohms
causes a total rise in r esponse of 0.5 db.
WILLIAM G. DILLEY
577 East Avery Street
San Bernardino, Calif.
4-in. = 4-ft.
Sm:
A couple of printer's errors seem to have
crept into my paper, "Extending the usef ulness of the Schober autotuner," which
was published in the October i ssue of
AUDIO. One is mer ely amusing and will
probably be spotted as such by most of
your readers; the other is somewhat mis·
leading.
f
Thus i n the second sentence of the paper
my "setting the temperament" came out
as "setting t he temperature." Later, in t h e
thir d sentence of t he final paragraph, the
paper should rea d "Organ pipes shorter
than abo nt 4 feet in length," not 4 inches.
WINTHROP S. PIKE
165 Hickory Court
Princeton, N. J.
1E
abIes you to demagnetize the p layback
head, if this is separate from the record
h ead, which you could not do by the expedient of turning off the power. Heads
should be demagnetized after about 8
hours of use.
TAPE GUIDE
(from page 28)
Demagnetization of Heads
Q. I have heard that l'ecol'd and erase
heads can be demagnetized by turning off
t he tape recorder or tape preamp power
while in the record position, due to the
collap sing of the bias and erase current
fields. Is this an eff ective method of demagnetization?
A . Demagnetization of a head is accomplished by means of an alternating
magnetic field of fair strength that
gr adually and steadily diminishes to zero.
If these conditions are met when the tape
recor der is turned off, demagnetization will
t ake place, although I don't know whether
this will be as eff ective as t he result of
using an external head demagnetizer specifically designed for the purpose. If I had
to b et on one technique versus the other,
I would bet on the head demagneti zer.
Depending on the design of the tape
recorder, it is possible that when the unit
is shut off the decline in the magnetic field
of the heads is too sharp to produce effective demagnetization. Furthermore, the
field may be too weak for good results.
Abrupt cessation of current through a
head is apt to magnetize the head. Hence
in some of t he better t ape machines a r esistive-capacitive network is employed to
prevent a surge of current through the
heads when the power is turned off or on,
or when the unit is switched b etween the
r ecord and playback modes.
To be on the safe side, I r ecommend use
of a head demagnetizer. This item is quite
inexpensive nowadays, being available for
$3 or less in some places. Besides, it en-
More on Demagnetization
Q. It is j'eoommended in the instruction
'manual of my tape recorder, as one of the
demagnetization steps, to remove a.c. power
from the recorder before demagnetizing
the heads and other metal parts that contact the tape. I n my case, the a.c. power
cOl'd receptacle is in a rather awkwal'd location for convenient plugging and unplugging. Th ere fore I wonder if I might
forgo t his step.
A. I see no point in removing the a .c.
cord from the house r eceptacle. I believe
that the instructions simply intend you to
m ake sure t h at the tape r ecorder is shut
off when you demagnetize the heads. If
oscillator current is flowing through the
reco rd an d erase heads, this may result in
imperfect demagnetization.
Demagnetizing Separate Heads
Q. When demagnetizing separate heads,
is it necessary to move the demagnetizer
several f eet away atter demagnetizing
ea.ch head, or is it jnst as effective to pTO'
ceed directly from one head to the next
until the last head is I'eached and t hen
move the demagnetizer several f eet away?
A. I think it is somewhat safer to withdraw the demagnetizer slowly from each
head th an to go from one head to the other
and withdraw slowly from the last . I n asmuch as the former procedure involves only
a few mom ents of extra. time, why not play
it safe ~
1E
SAVE
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CARBON
COMPANY
Electro-Mechanical Products Division
.J oh'nson burg, Pen nsylvania
80
RADIO MACAZINES, INC.
P.O. Box 629, Mineola, N.Y .
AUDIO
•
NOVEMBER, 1962
DVNACO
TRANSISTORIZED
PREAMP
lor <luper/alive <lounJ
(ft'om page 37)
Fit'st and second stage tt·ansistors .
From the number of low-noise transistor
types available the RCA type 2N175 was
chosen for stages one and two, mainly
because of its 3-pin base that fits a standard 3-pin socket. Suitable operation conditions provided, the noise figure of the
2N175 is about 6 db and thus well below the permissible values of F Ima ", and
FIlma",'
Output stage tmnsistors. Any desired
large-signal, audio-frequency transistor
having a maximum collector dissipation
of well above 75 mw may be used for
stage three. Again for reasons of the
convenient 3-pin socket '~he RCA type
2NI09 has been selected for the author's
unit.
Superlative sound means th e very best sou nd avail a ble, sound so realistic that
ski lled listeners can not distinguish the differe nce between "live" and "recorded" music
in a side by side comparison. This comparison has been performed dozens of times before thousands of people in programs sponsored by Dynaco, Inc. and AR, Inc. with
"live" portions performed by the Fine Arts Quartet. In these comparisons, the superlative sou nd capabilities of the Dynakits were amply demonstrated .since the vast
m ajority of the audiences readi ly admitted that they could not tell the difference between the electronic reproduction using the Dyna Mark III amplifiers and PAS-2 preamplifier and the instrumental rendition by the members of the Fi ne Arts Quartet.
Such perfection of reproduction means that listeners at home, using home type
components, can tru ly have concert hall re alism - a level of fidelity of reproduction
which cannot be improved regardless of how much more money were to be spent on
the components used. This is truly reproduction for the audio perfectionist, and a ll
Dyna components are of a quality level whith permits reproduction indistinguishable
from the original. This is achieved throu gh exclusively engi neered designs coupled
wit h prime qu ality components. Further, the unique designs and physical configuration
of a ll Dynakits make them accurately reproducible, so th at everybody can hear the
full quality of which the inherent design is capable. Dynakits are the easiest of a ll kits
to build-and yet they provide the ultimate in realistic qu ality sou nd.
FM-l-An outstanding FM tun e r with provision
for internal insertion of the FMX-J. Stereomatic
mu'ttiplex i ntegrator. The FM-I is 0 super-sensitive
(better than 4 /..tv), drift-free tuner with less than
.5% distort ion at all usable signal levels. Be tter
than 30 db separation on stereo usage using the
FMX-3 , and automatic transition to stereo with
. th e visual Ste reocator. FM - I kit $79.95, wired
$119.95; FMX-3 kit $29 ,95 ; FM -3A (Wi red tuner
with multiplex) , $169.95 ..
Resistors
All the calculations in the previous
paragraphs have been based upon the assumption that the resistors involved are
ideal and generate the thermal noise
"Which is due to their ohmic resistance
only. In reality, however, the noise voltage generated in a resistor normally is
several times the calculated value, depending mainly upon the physical structure of the resistor.
In order to obtain the required signalto-noise ratio, it is necessary to use lownoise resistors in critical places where
additional noise would invalidate the
calculations. Metal-film resistors have
been employed successfully in the author's unit, their noise factor being significantly lower than that 'of molded
composition and deposited carbon types.
(To be continued)
*SCA-35-lntegrated stereo amplifier and preamplifier
with
low
noise,
low
distortion,
and
moderate power output . 17 .5 watts per channel
continuous (45 wall total music power) with less
t han ·1 % distortion over the entire 20 cps to 20
kc range . Unique feedback circuitry throughout.
Inputs for all hi fi sources including tape deck.
SCA-35 kit $89.95; wired $129.95
PAS-2-Fully flexible stereo preamplifier wit h less
than . 1 % distortion at any frequency. Wide band ,
lowest noise with
every
necessary feature fo r
superb reproduction . Acclaimed throughout the
world as the finest unit available .
PAS-2 kit $59.95; wired $99.95
*STEREO 35-A basic power ampl ifier similar to
that used in the SCA-35 . Extremely low distortion
over entire range at all power levels. Inaudible
AUDIO ETC
hum , superior transient response , and outstanding
(from page 14)
controlling bias or charge, to tell it when
to go, go, go, straight into the nearest
amplifier.
A wild Canby guess-maybe all an electron beam needs i s to "see" a healthy pair
of variable anodes, deep down in the stereo
groove. Hmmm. Let's see now . . . With
these new semi-conducting, no-static r ecord
materials something might be done.
Would a modulated groove wall by any
chance absorb electrons variably ~ That
might do it. A handy dual circuit, from
stylus-cathode to r ecord-groove "plate."
Two beams, of course, and a common return via the record, each circuit directly
varied by the varying electron-sensitivity
of one stereo groove wall. It's a marvelous
idea-if it'll work. Almost as good as science fiction.
Definitely, this is not a Trend for 1963.
overload characteristic makes th is unit outperfor"l
components of much higher nominal rating . Fea tures new type Oynaco output transformer (patented design) . Fits behind PAS-2 or FM-3A units .
ST 35 kit $59.95 ; wired $79.95
*NEW~
STEREO 70-0ne of the most conservatively operated and rated un.its in the industry. The Stereo
70 delivers effortless 35 watts per channel continuous power. Its wide band Oyna circuit is un conditionally stab·le and handles transient wave
forms with min im um distortion. Frequency response .
is extended below 10 cps and above 40 kc without
loss of stability. This amplifier is admirably suited
to the highest quality home listening requirements
with all loudspeaker systems.
ST 70 kit $99.95; wired $129.95
LOWER PRICED COMPONENTS WITH FULL DYNA QUALITY
Write fo r descriptive literature
DYNACO INC . •
3912 POWELTON AVE . •
PHILA. 4, PA.
Cable: DYNACO Philadelphia
1E
AUDIO
•
NOVEMBER, 1962
81
NEW PRODUCTS
• lOO-Wa ,t t Transistor stereo Ampllfier.
A transistorized stereophonic amplifier
with a 100-watt power rating a t the 4-ohm
speaker connection, the A llied Radio
Knight KN-450A features a cool-running
I S- transistor circuit with two silicon rectifiers and no output transformers. H eat
generation is held to minimum. The circuit
features a military -type terminal broad
wiring arrangement. The 15 controls include: Four pushbuttons to select tuner,
phono, tape, or auxiliary sound sources; a
tape monitor switch; a separation control;
on-off switches are provided for both high
and low cut; and two switches are provided for channel phasing. Fuses are eliminated by a positive circuit-breaker d esign.
Five stereo inputs are provided, plus two
a.c. convenience outlets. A special stereo
hea dphone j ack for personal an d individual
listening is also standard with the unit.
Frequenc y response is plus or minus 0.5
db, 20 to 30,000 cps at r ated power; h armonic distortion is 0.5 per cent at rated
power; hum is - 90 db at tuner input and
-60 db at mag. phono input. Offered with
a dark brown textured metal case with
polished brass control panel, the KN- 450
is intended for 110-125 volt, 60-cps a.c. operation. It measures 3%. by 13% by 12%.
inches, including case, and is priced at
$189.95. An optiona l oiled walnut cabinet
is offered f or $14.95. Allied Radio Corp.,
100 North Western Ave ., Chicago 80, Illinois.
L -l
• Integrated Tone Arm. a.nd Cartridge. A
new, improved version of the Model M212/
216 Stereo Dynetic integrated tone arm
and cartridge, the Model M222, is being
offered by Shure Brothers. The new unit
comes equipped with the new Shure N22D
tubular stylus with 0.5- mil diamond and
is capable of tracking at %. to 1 % grams,
in part due to a stylus compliance of 22 x
10- 6 cm/dyne. The M222 is furnished with
improved plug and newly designed m a tching cable assembly for quick solder less
installation. The N22D stylus is a vailable
separately for existing Model M212/2 16
integrated tone arms. Packaged with each
N22D is a snap- on counterweight to reduce the tracking force of M212/216 tone
arms to %. to 1 % grams. The N22D m ay
also be used to replace the Shure N21D
stylus in Shure cartridges where %. to 1%
gram tracking is desired. Net price of the
M222, including stylus, is $89.50. Net price
of the N22D stylus separately is $24.75.
Shure Brothers, Inc., 222 Hartrey Avenue,
Evans ton, Illinois.
L -2
• PM-Stereo Ba.nge Extender. Designed to
double the primary reception range of FM
tuners, the Jerrold FM Range Extender,
Model FMX, makes it possible to overcome
the r eception range limitation of FMstereo broadcasting. With a minimum gain
of 20 db over the entire FM band, th e new
one- tube antenna amplifier helps reduce
background noi se an d "drifting" of sign a l.
The FM Range Extender has been engineered for simple indoor installation any-
where in the h ome between the antenna
and the FM tuner or radio. It may be
mounted in a n attic, closet, or on a ny convenient wall or tlat surface where a 117volt 60-cps outlet is available. The amplifier is extremely compact, weighing
slightly over two pounds. It incorporates
the latest 6DJ8 frame grid tube, insuring
sta ble, high-level performance. Design ed
for all-day continuous operation, the FM
R a nge Extender is provided with a shutoff switch, so that It may be disconnected
when not needed for long periods of time.
The current utilized by this equipment is
comparable to that used by an electric
clock. The FM Range Extender is priced
at $29.95 . Jerrold Electronics Corporation,
1 5th an d L ehigh Ave., Phila. 32, Pa.
L -3
• Miniature Speaker S y s tem. The University MINI 2- way speaker system is only
2-in. thick, 18-in. wide, 13- in. high, and
designed t o meet the highest possible
acoustic standards. The MINI utilizes an
open -enclosure d e sign, so that the batHe
board r a diates. This r e latively large radiating a r ea i s intended to reinforce the bass
and h e lp produce a smooth mid-range. A
separate tweeter adds highs up to 17,000
cps. The MINI is handsomely finished In
an oiled walnut cabinet. Price, $44.95. University Loudspeakers, 80 So. Kensico Ave.,
White Plains, N. Y.
L-S
• Stereo Tape Becorder. The Dua l TG 12
SK, at a price of $349 .95, features: 4-track
stereo-mono record and playback;
3
speeds; pushbutton controls; a utomatic
shut off; and no pressure pads for lowest
possible tape wear. Specifications include:
Frequency response of 40-20,000 cps ± 3 db
at 7 % ip s; signal-to-noise ratio of better
• Prec ision Condenser Microphon es. A new
series of precision condenser microphones
from B & K fea tures physical ruggedness,
high sensitivity, and an extensive selection
of accessories. Broad measurement range
of 10 cps through 100,000 cps at leve ls
from 15 db to 180 db is offered through the
choice of '4-, %-, and I-inch sizes. Two
different types are available for each diam-
than 46 db at 7% ips; wow and fiutter 0.15
per cent a t 7% ips; channel separation
better than 60 db from 30 to 25,000 cps. Included in the price are two microphones.
The TG 12 SK is a complete playbaclr system with two built-in speakers, one in
each lid, and a 10-watt stereo a mplifier.
United Audio Products, 12-14 West 18th
St., New York 11, N. Y.
L-S
• S tylus-Porce Gauge. This gauge is essentially an equal-arm bala nce which is
set on a plastic "knife- edge" pivot. In
chemistry lab we learned that the equalarm b a lance was the most accurate simple
eter. One type is adj u s ted to have overdamp e d resonance in order to give a tlat
O-deg. incidence free-field frequency response. The second type is a djusted to
h ave a critica lly damped resonance to produce the best possible pressure response
for closed coupler measurements. Typica l
applications are accurate measurements
for product sound control, precise acoustical calibration, defining acoustical environments, and boundary layer meas urements.
B & K Instruments, Inc., 3044 West 106th
Street, Cleveland 11, Ohio.
L-4
82
J
AUDIO
•
NOVEMBER, 1962,
®
Here's why Audio Magazine says Scott Kits are
"Simplest to build ..." and have
"Engineering of the highest calibre" *
SCOTT ®
H. H. Scott Inc., Dept. 035· 11
HI Powdermill Rd., Maynard, Mass.
Please rush me without charge your full
color brochure on the complete line of
Scott FM stereo tuner, stereo amplifier and
speaker kits. A sample 36 page full·color
Scott Kit instruction book will be included
if you enclose 50~ in coin or stamps.
Name ................. . ................. .
Address ................................. .
City .• •• •••••. .• •• ..... ... State ....•• •• •••
delighted by its handsome.>good)ooks. ~n
on you'll know for yourself Why the expert editor.s of leading
say .•. "only the .most sophisticated ergineering thinking could design
foolproof. as this :' • .... . . 4'
"L '
. <:.
If.any of your friends would like a copy of
the new Scott Kit brochure send us their
names and addresses.
Export: Morhan Exporting Corp., 458 Broadway, N.Y.C.
Canada: Alias Radio Corp., 50 Wingold Ave., Toronto
ImlagneCOrd
I
for
UNFORGETTABLE PERFORMANCES
• FM-Stereo Antenna. The new Winegard
"Stereotron" FM a ntenna for both stereo
a nd mono is a n 8- el ement uni t w ith a
built-in Nuvistor a mplifi e r that can be
u sed in any l ocation. The "Stereotron "
amplifie r takes u p to 200,000 !'v of signal,
so that it will respond to weak signals
fro m distant stations a nd strong local
signa ls w ill not overload it. It h as a mi ni mum gain of 26 db over a fo lde d dipol e
an d a fl at freq u e n cy response of ± IA db
The King of Swing Chose
Magnecord for the World's
First Stereo Tape Recording
of Popular Jazz
(Chicago's Blue Note-19Sll
It takes a real pro to stand the
test of time . . . a musician like
Benny Goodman ... a tape recorder
like Magnecord, the choice of professionals, the one most widely used
in the sound and broadcast industry.
Don't settle for less . . . your home
deserves the best! For incomparable
Stereo, you'll want the Magnecord
Olympian ... it's perfect! Has everything you've wanted including full
fidelity 4-track play and record.
write for additional information and
name of your nearest Magnecord dealer
ImlagneCOrd
MIDWESTERN
way to measure weight. Of cou rse, this
presumes the counte rweights are extreme ly accurate-i n t h is case p lastic
weights are s u pplied. In any case it is
q uite possibly an extremel y acc u rate
means of setting stylus force and at a
price of only $1.00. Aco u stic Research Inc.,
24 Tho rndike St., Cam bridge, Mass.
L-7
In his New York apartment, Benny Goodman
listens to his Magnecord Professional with Martin
Bettan , factory sales representative .
5 ALE 5
DEPARTMENT
INSTRUMENTS,
INC.
m a nufacturers of electronic data acq ui s ition instruments
P . O . BOX 7509
TULSA 35, OKLAHOMA
CIRCLE 84A
He
f r om 88 to 10 8 m c. Th e " stereotron " is
availabl e for u se with eith e r 300- ohm twin
lead or 7 5- oh m coaxia l cable. The a n tenn a
h as a perma n ent gold-a nodize d fini sh for
corrosi on protection. It can be purchased
without the N u v i stor amplifie r if d esired ,
and the "Ster eotron" a mplifier can be purchase d separately to be u sed with any FM
a nten na. Th e Stereotron an tenna only
(Mod el SF-8) lists for $23.65, a nd the
"ster eotr o n " am plifi er (Model AP- 320 )
li sts fo r $39 .95. Winegard Co. , Burlington,
Iowa.
L-8
• Speaker Kit. H . H. Scott an n o un ces the
first of its line of speaker kits . The Scott
SK-4 comes compl ete wi th cabinet in
walnut, mah ogan y, or un finished pine or
h ard wood. Directions are easy to fo ll ow .
It is patterned after the Scott S- 3 speaker.
Cabinet is factory -assemb l ed and prefin -
INSTRUMENTS
for AUDIO
MEASUREMENTS
MODEL 410 DISTORTION METER
• Measur.es audio dislortion, noise level and AC
voltages • Also a versatile vacuum tube voltmeter.
• Distortion levels as low as .1 % can be measured
on fundamental frequencies from 20 to 20,000 cps,
indicates harmonics up to 100,000 cps • Distortion
measurements can be made on signal levels of .1
yolt to 30 yolts tms • The yacuum tube voltmeter
provides an accuracy of ±5 % over a frequency range
from 20 cps tD 200 KC. For noise and db measure·
ments, the instrument is calibrated in 1 db steps
from 0 db to -15 db, the built·in attenuator pro·
vides additional ranges from -60 db to +50 db
in 10 db steps.
MODEL 210 AUDIO OSCILLATOR
• Provides a sine wave signal
100 kc • Output level within ±1
into 600 ohms {reference 5 kcJ
variable to above 150 mw • Hum
from 10 cps to
db when working
• Power output,
and noise, -70
db at 5 volts output· Distortion is less than .2%
at 5 volts output from 50 to 20,000 cps, slighlly
higher at higher output and frequency extremes.
These instruments are supplied with many B.C. station installations
for FCC Proof-of Performanc:e tests.
BARKER & WILLIAMSON, Inc.
CRadlo CommUllic«lion Squipntenl ,gince 1992
BRISTOL. PENNSYLVANIA
•
STillwell 8.6681
CIRCLE 848
84
ished. The three-way system has a highcomplia n ce, l ow-reson a n ce woof e r a nd
separate mid-range an d high-freq u e ncy
drivers. A multip le- crossover n etwork has
separate control s for t h e mid-ra nge and
tweeter d rivers. For further information,
write Department P, H. H . Scott Inc., 111
Powdermill Road, Maynard, Mass.
L-9
AUDIO
•
NOVEMBER, 1962
NEW LITERATURE
• Dyna.m.ic Beta Power Transistor Teste,r .
A n ew, e ight-page t echnical brochure d esc ribes the Hick ok Model 1885 Dyna mic
Be ta powe r t.ransistor tester. This twocolor brochure is availab le without c h arge.
Brochure RD1885 d escribes a versatile
transis tor tester whic h measures b e ta a nd
leakage from d a t a in clude d on a r o ll chart.
Tra n sistor manufacturer's s pec ifi ca tions ,
or the user's req uire m e nts can easily b e
the b asis for tra nis tor testing. The broc hure includes technical sp ecificati on s,
simplifie d schematic diagram s, a nd c irc uit
descriptions of the beta a nd leak age tests,
the variable duty c y c le pulsin g system,
a nd the variable p owe r s upplies. RD Instruments Division, Hi ckok Elec trical Instrume nt Company, 10514 Dupont Avenue,
C leve la nd, 8 , Ohi o.
L-IO
• Pu&hbutton Switch Ca;talog. This n e w
6-pa g e 2- color cat a log for the electronics
industry introduces the n e w Swithc r aft
"Tiny-Fra me" pushbutton s witc h. Th e
"Tiny-Fra me" switch, Series 970, is a
s m a ll, direc t-acting pushbutton switch for
application s where s pace is a t a pre mium .
It is avail a bl e in m a ny s witc hing circuits
a nd in lockin g or n o n-I ocldllg acti on. Th e
catalog, Engineering Speci fi cati on s Catalog
S- 301, a lso illustrates a nd describes
Switcheraft's "Littel Switc h es," "B u tton
Switches," " Cord Switches," " T S w itc h es,"
a nd many others. Thi s catalog w as d es igne d as an industry guide f o r e ngin eer s
o n s p ecia l and stan da rd pushbutton
sw it c hes. It li sts e n gin eerin g data, design
fea tures, dimensiona l draw ings a nd a full
page of app liac tion ideas. Write to Switchcraft, In c., 5555 N . El ston Avenue, Chicago 30, Illinois.
L-ll
• New Book. "Reproduc tion of S ound," by
Edgar Villchur is publishe d by his compa ny, Acoustic Res ear c h, an d is 93 p ages,
p ape r , a nd priced at $2.00, postpaid, direct
f r om pub lishe r only. This book is a nonmathematical analysis of the na ture of
so und a nd oC h ow r e pr odu cin g co mp on ents
wor k. The b ook may b e u sed as a gen e r a l
s urvey of principles for th e ll1te r es t ed layman, or as a pre-e ngine erin g s urvey a nd
introduction for professi on a l s . The first
few c h apters d eal with t h e f unda m ental
n a ture of sound and the standa rd s to b e
a ppli ed t o a high-fidelity r e pr odu c ing syst e m. A bri ef discu ssion of r ecor din g , w ith
e mphasis on stereo, is foll owed by a treatment of each of lhe reproduc in g el e m e nt s
in turn: pickup a nd n eedl es, preamplifie r s
a nd a mplifier s, s p eak e r sys t e m s , a nd fin a lly the liste nin g r oo m itself. Aco u stic
Research In c., 24 Thorndik e St., Cam bridge 41, Mass.
• Inte-rchangeability Directo'r y. A n ew a nd
e nl a r ged e d ition of the R C A Inte r c h a n geab ili ty Directory of fo r eign vers u s USA
receiving-type electron t ub es i s n ow availa ble. The n ew e dition, form No . LCE-1 97B,
indicates the USA direc t r e pl acement type
or s imilar type, if avail a bl e, for m or e than
8 00 foreign tub e types u se d prin c ipa lly in
A M an d FM radios, TV r ece iver s , an d
a udio amplifiers. Radio Corp or a ti on of
A m e ri ca, Electron Tub e Divis ion, I-larrison , N . J .
L-12
• CondOOl.Scd Semiconductor Catalog. A mpe r ex Electronic Corpora ti o n's n ew 15 page ca t a l og in cludes b asic specification s
of the n ew lin e of unive l-sa l comm uni ca tion s transistors m a11ufact ure d by t h e
PADT (Post Alloy Diffu s ion) process. Th e
catalog a l so conta ins a complete li sting
a nd s pecifications of a com pre h e nsive lin e
of germaniu m pnp a nd npn a udio (small
an d large signal), computer, sw itching
(high a nd l ow s p eed ) a nd VHF tra n s istor s
for co nve r te r, mixer, and oscill ator app li-
cations. Also liste d with s p eci fi cation s are
t. he compl ete Amperex lin es of ge rm a nium
a nd s ilicon diodes, including silicon r eference and pow e r r ectifie r t y p es. Free copies
of the conde n sed Amperex Semicond u c t or
Cat a log m a y b e obtained b y writing on
your company letterhead to Ampe r ex El ectronic Corp., Advertising D e par tm e nt, 23 0
D uffy Avenue, Hicksville, Long I s la nd,
New York.
AUDIO
•
NOVEMBER, 1962
~
NEW VELOCITONE MARK II
why it's the finest stereo cartridge
you can use with your reoord changer
It isn't as if the new Mark II won't work wonders with your transcription turntable and arm. That it would. But, matching a cartridge to a record changer is
the far more challenging problem. It's a tougher nut to crack.
Here are some of the problems. You can select one of those ultra-high-compliance
magnetic cartridges that track at a gram or two. Now what?
Says Joe Marshall, noted authority in the January, 1962, issue of High Fidelity: .
"An attempt to reduce needle pressure with an arm not designed for low n eedle
pressure will usually result in high distortion due to loading the needle with the
mass and friction of the a1"1n."
And in the April 7, 1962, issue of Opera News, Conrad Osborne observes: "The
thing to be SU1-e of when seeking a new ca1·tridge is that the compliance . . . suits
the characteristics of your tonearm. A cartridge with extremely high compliance
wilt not necessarily turn in better performance with arms on changers, or with
m.anual tu?·ntable arms 1-equiring fai1-ly heavy stylus pressure . .. "
Now let's take a look at the Velocitone Mark II. Compliance: 5.5 x 10-6 em/ dyne,
designed to track at from 2 to 4 grams. Perfect! Also because it is a ceramic
transducer, you can play it with an unshielded motor-in an intense magnetic
field-without a trace of magnetically induced hum. Fine! But, how about frequency response, output, channel separation? How does it perform?
The usable response of the Mark II extends from 20 to 20,000 cycles - ± 1db to
17,000. And it has better than 30db channel separation. What's more, it is supplied with plug-in, matched equalizers so that it functions as a constant velocity
transducer, and can be fed directly into the 'magnetic' phono inputs of any stereo
preamp. Universal terminal plug eliminates soldering to arm leads.
Its output is in the order of llmv per channel. You can
operate your amplifier with lower gain settings and
with less power, resulting in improved signal-to-noise
ratio, lower distortion. What more could you ask?
The Velocitone Mark II is priced at $22.25 with two
0.7-mil diamond styli; $19.25, diamond/sapphire;
$14.75, dual sapphire. Ask your hi-fi dealer to show
you and demonstrate the new Velocitone Mark II.
SONOTONE CARTRIDGES
Sonotone® Corp . • Electronic Applications Div . • Elmsford, N. Y. Canada: Atlas Radio Corp .• Ltd., Toronto
Cartridges. Speakers. Tape Heads. Microphones. Electron Tubes. Batteries. Hearing Aids
85
1
COMING ATTRACTIONS
1
Another Word on Multiple Speakers.
J. W. Ward
The outstanding virtue of multiplespeaker arrays consists of the way
they handle the mid-range. A midrange multiple-speaker array is p resented and variables that affect performance discussed.
2
A l-Megacycle Frequency-Compensated Audio Attenuator.
Weaver Dodge
An audio attenuator can be used
to calibrate test equipment, check
equalization and amplifier capabilities, and provide a precision lowlevel signal for measuring input
noise and hum. Complete with construction details.
It's what you don't hear that counts!
That's why you buy a turntable. For silence. Silence of oper·
ation. Rondine 2 delivers both the sound and the silence
you wa nt. Min us 57 db silence even at fullampl ification.
That's wh at you wa nt in a turntable, what you're sure of
getti ng wit h Rondi ne 2. Combi ne it with the Auto·Poise*
tonearm and you have the worl d's only true turntable with
fuJ.!y automa tic operatio n. For complete catalog, write Dept.
A-ll. Rek·O·Kut, 38· 19108th St., Corona 68, New York.
3
Leakage Inductance-A Useful Circuit Component.
Norman Crowhurst
leakage inductance is available in
many audio circuits but is not often
utilized fully. Here are several examples of normally ignored applications, and explanation of how
they work.
R Stereotabl e only .... ..... ... c .. . . .... .... $79.95
R 32 0 with S 320 Tonearm . ...... . .. . . ... ... 129.95
R 320 A (illustrated) with Auto·Poise Tonea rm ... 169.95
R Base (oil ed walnut fin ish) ..... . . . . . . . . . . .. 14.95
~K-O-KUT/ rondine~ 11
CIRCLE 81SA
200-WATT AMPLIFIER
RECORDS
Sound-onound
NEW LAFAYETTE
Deluxe
Professional
Quality
(fl'om page 52 )
a tr ansistor amplifier. The difference .is
that a transistor can be overheated only
once.
Treated properly, installed where
there is r easonable ventilation, and
never short circuited, this transistor
amplifier should prove to have extremely
long f ailure-free life with no need for
periodic maintenance or adjustment. IE
4-TRACK
STEREO
R E FEREN CES
T~~n~an~o~e~K 99~~YDOWn
Stereo Record! Play Preamps .
Burwen, R. S., " Transistor music system using direct coupling," AUDIO, Vol.
43, No.8; p. 21; August 1959.
Burwen, R. S., "Portable transistor
music system," JAES, Vol. 6, No.1 ; p.
10; January 1958.
SHOWN WITH
OPTIONAL CASE
Begin your stereo component system with this oustanding tape recorder reproducer. Superb Electronics, smooth, dependable tape transport. Plays: 4-Track
Stereo Tapes, 2-Track Stereo; 4-Track, 2-Track and Full Track Monophonic. Records 4-Track Stereo or Mono; Sound-on-Sound .Frequency Response 40-18,000
cps at 7¥2 ips. 2-Speeds: 3314 ips & 7¥2 ips. Plays Reels up to 7
inches. Complete with 4 connecting cables and empty tape reel.
RK-143WX as above but with carrying case . .
Net 114.50
TAPE SYNC
D
r~--------------------I
AK-2.
10,
l.1.,
'lL:~~~;;\ i
LAFAYETTE Radio ELECTRONICS
I
I
DEPT.
BOX
RK·140 Tape Deck $
Syosset,
Rush me FREE
N.Y.
. .... Enclosed
• NAME
I AOORESS
I CITY
..
ZONE _
_
388 Giant Sized
..........
Pages 1963 Catalog
LAFAYETTE Radio ELECTRONICS
Syosset, L.I., N.Y •
J
. OTHER LOCATIONdS:
amalca 33, N.Y. Scars ale, N.Y.
New York 13. N.Y.
Paramus, N.J.
Plainfield, N.J.
Newark 2, N.J.
Bronx 58 , N.Y. Boston 10, Mass •
STATE_·_ __
Natick, Mass. OPENING FALL 1962
II
I
--------------~-----------~
CIRCLE 86B
86
I
(from page 26)
her e and menton the scheme that is probably the simplest of all. Merely use a
stereo or other multitrack recorder and
r ecord the sync signal as one of the
tracks, hoping the separation is sufficient
to prevent hum on the track containing
the program material. The reference sync
can be either from a step-down trans-
AUDIO
•
NOVEMBER, 1962
former, from power supply ripple, or
from a generator mounted on the camera.
Hardly any disadvantages are present
with this system except that a stereo
machine is required, which could be a
little heavier, and the resulting audio
signal would be only a half-track recording. This also necessitates an inventory of new machines and makes the
thousands of single-track recording machines obsolete. In some cases the economics involved will prevent us from
converting to stereo machines just to record single-track sound. One manufacturer in this country markets a machine
using the above scheme. The machine
was designed to record audio on one
track and sync only on the second and
does not carry the extra weight of a
complete second channel as would be the
case of a normal stereo machine.
... Another System
We now come to another new system
that you might think was devised just to
confuse the issue. The writer set up the
criteria as follows: It must be usable
with any professional or semi-professional tape machine recording at any
tape speed with complete compatibility;
it must not require any special machining or installation on the tape machine
itself; it must be reliable and require no
special operating conditions. In other
words if the tape machine will run and
record on the tape being used no matter
what the condition of the tape, and will
produce acceptable results, the sync system will be well within its design tolerances. To top it all, it must not add hum
or other extraneous signals to the recording that cannot be eliminated conveniently. This sounds almost too good to be
true. One disadvantage, that may really
be an advantage is that the recordist
must carry along two small "black boxes,"
to use this system (see Fig. 4). This of
course means this scheme can be used
with any machine available. If you break
down in the hinterlands, pop into any
radio station and borrow their machine
to finish the job. What happens if the
"black box" breaks down ~ All we can
do is design it to be very reliable, utilizing a minimum of special components
and to operate under extremes of conditions. The writer's unit has been tested
with line voltages ranging from 75 to
130 with both new tubes and with tubes
of low emission. The system uses a vacuum tube, as indicated, but could be done
with transistors, about 3 or 4 of them.
However, inasmuch as we have to plug
the box into line voltage, it was decided
that low-voltage d.c. was just as hard to
come by as medium-voltage d.c. so a vacuum tube was used. The system uses a
sub-audible sync tone locked to the 60CpR line frequency. The sync generator is
a 30-cps multivibrator locked to 60 cps
and the wave shaped to a 30-cps sine
AUDIO
•
NOVEMBER, 1962
wave with less than 1 per cent total harmonic distortion (see Fig. 5). It is impressed on the track at a - 20 VU level,
so it can be monitored on the VU meter,
and can be injected into the system anywhere. It works perfectly with the Ampex 600 series machine because it can be
plugged into the line input and still have
the mic input. for audio. On single-input
machines an adapter would have to be
built, but this should be no problem
since the sync generator has a built in
100-k isolation resistor that has handled
all problems so far. In some cases an
adapter socket can be used-the type
that has a one-to-one straight-through
wiring with the tube pins brought out to
tie points. The second "black box" contains a filter to eliminate the 30 cps from
the program material. This could be installed in the machine but that would remove the compatability claim. A sharp
high-pass filter or a resonant bandreject filter can be used and in both cases
would preserve all the low frequencies
necessary for excellent-quality voice l'ecordings. The writer also plans to use
a bridged-T configuration in the threeposition mixer now being constructed
specifically for use with this system and
an Ampex model 601 recorder. The necessary filter design to preserve the "external only" criteria presents some formidable problems, mostly financial.
While the 30-cps generator is relatively
inexpensive, the 30-cps reject circuit can
be very costly. To install the filter in the
mic line means high-Q coils and large
values of capacitors, all of good quality.
A balanced mic line also contributes
more to the cost. All must be well shielded and if you use mics of radically different impedances, more than one box is
needed. These filters are relatively maintenance free, but a transistor or tube
type filter could be built, probably at
less cost than the passive configurations
designed. The author, at this writing, is
using a 30-cps resonant reject filter that
passes all frequencies from 50 cps up
with no attenuation. Theoretically this
should work well, but also presupposes
that during playback the "acceptance"
circuit would pass 30 cps only. In practice this is hard to accomplish, so those
circuits also receive enough energy up
to approximately 70 cps to affect the
sync signal. Manual transfers are possible, however, with the operator ignoring the sync signal display "bounce."
A sharp high-pass filter with a nominal
SO-cps cutoff would eliminate this problem, but would reduce the desirability of
this system for sync music recording.
This does not bother the writer because
it is firmly believed that music should
be done under other than "portablestrapped-on-your-back" conditions. Music should be recorded using studio type
equipment only, unless it must be done
for an effect or other reasons, but then
EXPERIMENTAL
·Stereo Cartridge
In October, 1960, GRADO intro·
duced a tone arm which was pri·
marily designed for laboratory
research. Nothing was spared in
the design parameters of this tone
arm since all future designs were
to be based on this concept. It
contained features and perform.
ance characteristics far in advance
of any tone arm ever offered to
the public. Consumer acceptance
was immediate. Never before (or
since) has a tone arm been so uni·
versally acclaimed as the BEST.
It has since become the interna·
tional standa rd of excellence.
Similarly, GRADO has conceived
a cartridge which was designed
exclusively for stereo reseorch ond
development. This cartridge is not
a mono·stereo compromise, it is
designed to play only the stereo
disc, but to the highest degree.
Since the effective complionce is
extraordinarily high (more tha~
twice that of our Lab cartridge)
and the moving mass at the stylus
tip extremely low (it resonates ot
approximately 50,000 cps) ploy·
back distortion is a thing of the
past and if it weren't for dust, dio·
monds and records would lost
forever. Tracking forces range
from 2/10 of a gram to 1 gram .
Since these experimental cor·
tridges are assembled in our
research division, under the per·
sonal supervision of Mr. GRADO,
it can be appreciated that avail·
able quantities will be severely
restricted. Each cartridge is
covered by a diamond stylus guar·
antee of five yeors and uncondi·
tionally guaranteed for one year.
Price $75.00
Patent #3,040,136
For further detoils write to:
GRADO LABORATORIES, INC.
4614 7th Avenue, Brooklyn 20, New York
Export-5imontrice, 25 Warren St., N. Y. C.
87
NEW
ARGOS
SPEAKER SYSTEM
with 2 ~ENSEN speakers
Outperforms
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Use it anywhere - shelf, table, wall or floor only 18" x 12" x 3 3,4" thin. Ideal for stereo. New
high-compliance Jensen woofer has up to 200%
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• Screw terminals polarized for stereo. Volume control
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PRODUCTS COMPANY
Dept. #1 , Genoa, Ill inois
STATEMENT REQUIRED BY THE ACT OF AUGUST 24.,
AMENDED BY THE ACTS OF MARCH 3, 1933, JULY
AND JUNE II, 1960 (74 STAT. 208) SHOWING
OWNERSHIP, MANAGEMENT, AND CIRCULATION
1912, AS
2, 1946
THE
OF
AUDIO, published Monthly at Lancaster, P a., for October I, 1962
1. The names and addresses of the publisher, editor, managing editor, and busi·
ness managers are: Publisher: Charles G. McProud, 204 Front St., Mineola, N. Y.;
Editor : David Saslaw, 204 Front St., Mineola, N. Y.; Managing editor: none; Business manager: Henry A. Schober, 204 Front St., Mineola, N. Y.
2. The owner is: Radio Magazines, Inc., 204 Front St., Mineola, N. Y.; Henry A.
Schober, 204 Front St., Mineola, N. Y.; Charles G. McProud, 204 Front St.,
Mineola, N. Y.
3. The known bondholders, mortgagees, and other security holders owning or holding 1 per cent or more of total amount of bonds, mortgages, or other securities are:
none.
4. Paragraphs 2 and 3 include, in cases where the stockholder or security holder
appears upon the books of the company as trustee or in any other fiduciary r elation,
the name of the person or corporation for whom such trustee is acting; also the
statements in the 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.
5. The average number of copies of each issue of this publication sold or distrib·
uted, through the mails or otherwise, to paid subscribers during the 12 months
preceding the date shown above was: (This information is required by the act of
June n, 1960 to be included in all statements regardless of frequency of issue) .
35,000
(Signed) HENRY A. SCI-lOBER, Business Manager.
Sworn to and subscribed before me this 14t.h day of September, 1962.
(Seal) Edmund H. Strecker , Notary Public.
S ta te of New York. No. 30-3874750. Qualified in assau County. Term expires
March 30, 1963.
88
this system wiJl work as well as the othel'
compromises mentioned before. In transfer, the sync component must be removed f rom the progr am unless the playing equipment will not pass 30 cps.
Being an almost pm'e sine wave makes
the chore rather easy eitheI' with the
normal high-pass Biters in all photogr aphic channels or dialog equalization
of some sort. In practice it is possible
to put the 30-cps signal well below the
ta p e noise and stage noise with no stra in
and absolutely no change in audible voice
quality .
It is hoped that this article will kindle
the r eader's imagination or dander or
both and thus promote more study and
sear ch for the "perfect" tap e synchronization system.
1£
TRACKING ANGLE
(f1'om page 24 )
from one record to the n ext also cause
problems of channel separation. It is
surprlsmg, but frequently differ ent
amounts of crosstalk can be measured
with the various r ecords. Sometimes
crosstalk is high from the left to the
right channel, and low from the right t o
the left channel, and vice ver sa.
F igu1'e 7 demonstrates what happ en '
when the picku p is incorrectly positioned. The amount of chan nel separation will vary with the angle a.. If everything is correct in both cutting and
playback, two identical cunes will be
obtained for crosstalk on the lef t and
right channels. However, measurements
show that two identical cm-ves are not
obtained in all cases. This can be due t o
geometrical faults in the construction of
the pickup, but if these are elimina ted
it is found tha t widely differing r esults
are obtained when measuring the various
test records.
Figtwe 7 shows a drawing of the ster eo
groove. cp is the vertical tracking angle
and ~ is the cu tting angle. x is 45 deg.,
the half angle of the angular distance
between the two minimum points for the
two curves for cr osstalk as a f un ction of
the angle variation a..
If we assume that the cutting direction
is 45/45 in the cutting plane, there is
the f ollowing r elation between the three
angles:
tan x= cos (P
cos B
If we know qJ and measm'e x we can t hus
fin d ~.
Figttl'e 8 gives the e curves for various
phonograph records. The B & 0 pickup
was used in measuring these.
Since the vertical cutting angle varies
from r ecord to r ecord, it i not possible
to find any ideal pickup construction
until standards can be agreed on.
The fact tha t the vertical cutting angle
I S in r eality not vertical results in the
AUDIO
•
NOVEMBER, 1962
determination that the stylus tip should
not be vertically oriented. F 'i gure 9
shows what happens if the stylus angle
is not in agreement with the cutting
angle. This is a point which is frequently
difficult to impress on p eople, even professionals . Gener ally there is the feeling
that a pickup stylus should angle forward very slightly in order to avoid
damaging the record. In reality this is a
great misunderstanding. Due to the r ecording conditions, the stylus tip should
in reality point in the opposite direction,
and exactly as much as the cutting angle
varies from the vertical line.
After a cold and sober theoretical
consideration, the stereophonic phonograph r ecords should in r eality be intolerable to listen to. However, practice
r eveals a different situation. Even
though the experienced ear can probably
hear the greater distortion, there is no
doubt that the stereophonic effect is such
a great advantage tha t considerably
more distortion can be tolerated than is
the case with mono records. On the basis
of li tening tests it seems that su ch high
demands for distortion reduction in
stereo systems are unnecessary as compared with single-channel systems. This
should not draw attention away f rom
the sources of faults that can he removed
with the greatest ease by merely establishing standards.
In the IEC-publication 98 and 98-1,
which contains recommendation for commercial ster eophonic records, the problem about the cutting angle is not mentioned. However this publication is being
revised. At the IEC-meeting in Helsinki
last year the Danish delegation proposed
to standardize this angle at 15 deg.:
(This propo sed was made in Ewrope
bc/07'e the essentially EU1'opean committee. See the EeZit01'iaZ /01' /~/.1"the1· comm ents about the status ,in the U. S . ED.)
The proposal contains the following
definition of the natUl'e of the groove:
" The stereophonic groove shall carry
two channels of information . The two
channels shall be recorded in such a
manner that they can be reproduced by
movement of a reproducing stylus in
two directions at 90 deg. to each other
and at 45 deg. to a radial line through
the stylus tip and the center of the disc.
" The r eproducing stylus motion shall
be tangent to or lie in a plane through
the stylus tip and 'the record center, inclined at a nominal angle of 15 deg.
clockwise to the normal through the
stylus tip as viewed from the center of
the disc."
It is hoped th at the changing of Publication 98 and 98-1 will be confirmed as
soon as p ossible, and that the different
record makers will adopt this stand ardization as soon as possible.
.lE
(from page 56)
It will be noted tha t some of the cir- quencies is not pel'ceptible. But the r ecuit values in F ig. 4 are different from sulting 10-db decrease in insertion loss,
those in the Bauer prototype. The values however, is much to be desired.
in the original cir cuit were arrived at
The balance-control potentiometer
analytically, and they do not necessarily plays an additional role. When it is
r epresent practical values. For example, centered each half of it appears in
toler an ces on the inductors have been parallel with one of the phones. Since
brought into line with those of t he rest the CC-l is designed to work with 8-ohm
of the circuit. Also some capacitance phones th e resulting parallel resistance
"alues have been changecl slightly . An is close to 5 ohms, the desired load. The
important change is the substitution of use of 4-ohm p hones is also p ossible
100-ohm resistors for the 600-ohm re- with only a slight cleCl'ease in sensitivity .
. istors in series with each source. The
purpose of the high r esistances was to Operation of the Control Center
bring the crossfeed factor below 200 cps
Most low-impedance dynamic headas close to unity as possible, but when
this was done the insertion loss of the phones are remarkably sensitive; a
unit increases (more about this la ter in power level of 5 to 10 milliwatts is
a discussion of power requirements). usually sufficient to drive them t o norThe use of 100-ohm r esistors results in mal peak listening level. If they were
an insertion loss of 30 db comp ared with oper ated directly across the output of a
a loss of more than 40 db in the p roto- power amplifier, hum and tube noise
type circuit. Thi s is done at the expense would be quite audible even with the
of about 1.5 db of crossfeed factor. sign al present. There would also be the
Listening tests have shown that a dif- possibility of inadvertent overload of
ference of this magnitude at low fre- the phones and excessive sound pressure
•
NOVEMBER, 1962
noise-free
recordings
you have
ever
heard
REFERENCES
C. D. O'Neal, " The pyr amid stylus," IRE
l 'mnsactions on Audio, December 1959.
M . S. Corrington and T. Murakami,
"Tracing distortion in stereophonic disc
r ecordi ng," RCA Review, June 1958.
C. C. Davis and J. G. Frayne, "The West·
rex stereo disc system," P1'oceeclings of the
IRE, October 1958.
B. B . Bauer, " Trackin g augle in phonograph pick-ups," Ek!ct1'onics, March 1945.
J. A. Pierce and F. V. Hunt, "On distortion in sound repr oduction from phonograph r ecords," J.iJ..S.iJ.., July 1938.
Erling P. Slwv, "Ster eo disc problems,"
A.E.S. J01wnal, J anuar y 1960.
HEADPHONE CONTROL
AUDIO
the most
will be made on the new all·transistorized Norelco
Continental '401' Stereo Tape Recorder, the only
recorder using the newly developed ACI07 tran·
sistors in its two preamplifiers. The ACI07 is the
only transistor specifically des igned for magnetic
tape head preamplifiers utilizing specially purified
germanium to ach ieve the extraordinary low noise
figure of 3 db, measured over the entire audio
band (rather than the usual single frequency). This
noise figure remains stable over large collector·
emitter voltage swings and despite large variation s in source resistance .
Hear the new transistorized Norelco Continental
'401' • 4·track stereo/ mono record and playback
• 4 speeds: 7Yz , 3%, I Va and the new 4th speed
of ' 7(6 ips wh ich provides 32 hours of recording
on a single 7" reel • fully self·contained with
dynamic stereo microphone, two speakers (one in
the removable cover for stereo separation), dual
preamps and dual recording and playback amplifiers • se lf-contained PA system. mixing facilities
• can also play through external hi-fi system •
multiplay facilities,
Specifications: Frequency response : 60-16,000 cps
at 7Yz ips. Head gap: 0.00012". Signal-to-noise
ratio : better than 40 db. Wow and flutter: less
than 0.4% at 7Yz ips. Recording level indicator:
one·meter type. Program indicator: built-in, 4·digit
adjustable, Inputs: for stereo microphone (1 twochannel); for phono, radio or tuner (2). Foot pedal
facilities (1), Outputs: for external speakers (2),
for external amplifiers (1 two-channel); headphone
(1). Recording standby. Transistor complement:
AC 107 (4), OC75 (6), OC74 (2), OC44 (2), 2N1314
(2), OC79 (1). Line voltage: 117 volts AC at 60
cycles. Power consumption: 55 watts. Dimensions:
16'71', ' x 1571',' x 8%". Weight: 43 Ibs. Accessories:
Monitoring headset and dual microphone adapter.
For a pleasant demonstration, visit your favorite hi-fi dealer. Write for Brochure D·ll. North
American Philips Company, Inc., High Fidelity
Products Division, 230 Duffy Avenue, Hicksville,
Long Island, New York,
~reko®
In Cana da and throughou t the free world . tlore/eois known as 'the Philips.
89
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Technical Appliance Corporation
Dept. JTD-59, Sherburne, New York
A Subsidiary of The Jerrold Oorporation
CIRCLE 90A
90
in the listener's ears when connected in
this fashion. Thus it is customary to
operate high-quality phones with about
20 db of attenuation in the input to the
phones. Resistance in series with each
phone is necessary in the Bauer circuit,
and this accomplishes the desired attenuation. The prototype circuit has 40 db
of attenuation whereas the CC-I control
center has only 30 db. This will give us
an idea of what kind of power amplifiers
are necessary to drive the system. If 10
milliwatts of power is required for
peak output in each phone, then each
amplifier channel must be capable of
10 watts output. This should be termed
"available" power since it is available
to but not actually drawn by the system. Obviously more power would be
necessary to drive the prototype. The
100-ohm input impedance of the CC-l
does not represent an ideal load for a
low-impedance amplifier output, but in
this day of well regulated power amplifiers no problems are likely to be encountered.
The user should first turn down the
amplifier volume before switching the
unit from phones to speakers since all
attenuation is being taken out of the
lines. Uncomfortably loud levels may result if this is not done.
The second control from the left on the
panel of the CC-I gives the listener the
choice of energizing each phone separately or both simultaneously in either
stereo normal or reverse modes. The first
two of these positions are to be used in
stereo listening, but by using them in
conjunction with the middle switch the
user can explore the full range of possibilities of the system. It is felt that
this flexibility will be of use to experimenters in electroacoustics and to engineers in the recording field.
If a listener wishes to hear a singlechannel program, he can do it in a number of ways. He can simply energize one
phone (this is the only real meaning of
the term "monaural") . Or he can energize both phones with the same signal
("diotic" is the correct term for this).
There is listener fatigue associated with
the first of these methods since it does
not approach any normal listening condition. Finally, the user can place the
second switch in either the "Right Only"
or "Left Only" position and the middle
switch in the "Space Perspective" position. Then the virtual source will be
either 45 deg. to the right or left with
localization taking place naturally.
Listener reactions have certainly favored
this way of listening to a single-channel
signal.
Subjective Ev-aluations of Listening
With Space Perspective
The Space Perspective system has been
used with every type of stereo record-
LOOK···
THIS
PHOTO
STEREO CARTRIDGE
MODEL SX- I
--
SONOVOX CO.. LTD.
10 1T o k; w crr.o t su-ChO.
S h i bu yo.
T o ky o. lop or.
CIRCLE 908
LOWEST DISTORTION! Never
exceeds 0.3% at sound pressure
levels to ll5dB . Switchable attenuator; l5dB before preamplifier.
FRONT TO BACK RATIO Highest wideband rejection over
the important midrange: at least
26dB.
COMPARE THE SCHOEPS in
your own studio or on location.
You will find the Scboeps system
vastly superior to any condenser
microphone. Write or phone for
demonstra tion. Literature avail-
able on request.
International Electroacoustics
Inc.
333 Sixth Ave., New York 14. N. Y.
212 WAtkins 9-8364
CIRCLE.90C
AUDIO
•
NOVEMBER, 1962
FOR FULL QUALITY
STEREO-MULTIPLEX
OR MONOPHONIC
FM RECEPTION
USE
FINe0
Model FM·.4
World's Most Complete
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FM ANTENNAS
The Top Performance Line!
Ask your dealer to explain the advantages of these
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THE FINNEY COMPANY
34 West Interstate
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Dept. A
CIRCLE 918
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NEW YORK 6, N.Y.
CIRCLE 91C
ing available. As expected, its most
dramatic effect is with recordings exhibiting extreme instrumental separation. In a sense listening without it is
rather like looking into a stereoscope for
which the pictures had been taken with
an interocular distance of, say, three feet
instead of the normal three inches. Extending our analogy, the effect of Space
Perspective on a widely separated recording is like reducing the interocular
distance-thus lessening the parallax
and drawing the picture into normal
perspective. This analogy is only qualitative, for the notion of convergence is
not as clearly defined for binaural hearing as it is for binocular vision.
Recordings with an equally-fed center
microphone have been mentioned earlier.
Where there already exists considerable
crossfeed between the channels (that
provided by the common microphone),
the addition of more crossfeed by means
of Space Perspective is rather subtle and
in some cases barely noticeable. Recordings made with fairly closely spaced
omnidirectional microphones may sound
equally well with or without Space Perspective due to the high signal mutuality
present in the sources.
An interesting phenomenon observed
in using Space Perspective is the apparent elimination of excessive reverberation where there is an abundance of it.
The psychoacoustic mechanism is not
at all clear, but it is suspected that in
these recordings the reverberatory information is different in each channel.
Without Space Perspective each ear
hears separate reverberatory information; this is not natural and may give
rise to a bizarre and unreal sensation
of vastness and spaciousness. Adding
Space Perspective lessens this difference
in reverberatory information thus tending to produce a more natural auditory environment. The ear probably
equates a decrease in the sense of vastness with a decrease in reverberation.
Some observers have noted a slight
drop in bass when switching to Space
Perspective while listening to material
with a preponderance of bass in one
channel. With the circuit switched in, the
two phones are virtually in parallel below 200 cps, and with the rather large
series resistances each phone is effectively
being driven by a constant-current
source. Consequently any change in load
impedance will be r eflected by a change
in voltage across the load. Thus paralleling of the phones at low frequencies
reduces slightly the level of any bass
present only in one channel. The system is dramatic in its correction of inappropriately recorded material and
only slight in its effect on material which
already possesses strong signal mutuality
between channels. But in every case it
preserves the spatial geometry which the
recording director had in mind.
1£
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BY TELEFUNKEN!
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I American Elite, In(., Dept.IO, 48-50 34 St., l. I.e., N. Y. I
I ~~~~~~ ~~ndTer:~unf~~~ is:f:~;o:~~:m~~:d technical I
I Name... .
I
I
I Address. .. ..
t ~:t:~~~~ . . : . .:. : . : . . . . :..:. :::::~~:::i;;~nState==-l
CIRCLE 91A
AUDIO
•
NOVEMBER, 1962
9\
PURCHASING
A H 1-F I"
SYSTEM
.~
•
TIME PAYMENTS AVAILABLE
Up to 2 years to payl
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IJ~~
Noted.. e •
~ur?n'~~~'-:'~
> ~d~ "'~~t~~;;:r~~~1~
:---CLASSIFIED--.
u. s.
P a t en t Office h as issu e d P a t e nt No .
3, 055,98 8 to Shure Broth e rs fo r th e moving-m agnet Dyneti c cartridge. Th e pa t e nt
a lso covers th e sty l us s u s p e n s ion system
of some of the Shure Ste r eo-Dyneti c car tridges. App li cati on for th e p a t ent w as
fi l ed on April S, 1 957, u po n introduction of
the compa ny's o riginal !VI1 Dyn e tic cartridge .
New F airchild stereo Cartridge. Shown
fo r the first time at t h e r ecent New York
High Fidelity Show in d evelo pm e nt for m,
the n ew F a irc hil d " F-? " r e p.·esen ts a d e parture from. p'revious Fairchild d esig ns.
Utilizing a t r a n s istor amp l ifi e r to pro v ide
the r e quire d gain, the n e '\T cartridge conce ntra t es o n t h e main problem of a car tr id ge, that is to tra ce th e g r oove prope r ly.
Thu s, th ey h ave d es i gned a ve ry
i O \ V -I1:laSS
cartrid ge which d oes not in corp or ate t h e
r e la tive l y la r ge gen er a t or u s u a ll y associa t e d with co n ve ntion a l cartrid ges. Th e
approach i s sa id to o fC er great p r omise.
Remote Voltune Control P a tented. A lexi s
Badmaieff, ho lde r of 27 p ate nts in t h e
fi e lds of e lect roni cs a nd acou s tics a nd
c hi ef engil1eer of the Aco u st·cs -T.·a n s ducers at A ltec Lansing Corpo ration, i s
t he lI1 ve nto r of th.s n ew concept for r e mote volume contro l of so und systems.
Call e d "Revocan," t h e unit i s d esign e d to
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aren a s, a udito riulTIS, s ta diullls, theatres,
a nd o th er a r eas of mass gathe rin gs. The
unit prov id es m ea n s fo r contro llin g the
gain of an am pli fie r from a point away
from th e am plifie r 's locati on.
A l so, a l most s imultan eou s l y with the
a nnouncem ent of th e a bove patent, Altec
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org a niza tio n in 1937, when it ass um ed r e sponsibility for the in s talla tion a nd main tenance of a major p o r tion of the motion
picture
indu s try's
so und
r eprodu cing
eq uipm ent.
S ounde'r a,f t Sales S aar. Alth ou g h August
i s t r a ditio n a ll y a p e riod of l ow sales,
Soundcraft Co rpor ation a nno un ced t h at it
brol{'e a ll existing sales r ecords fo r a
s ingle month. In ad diti on , i t was a n n oun ce d t h at th e compa n y's eight months'
sales h a d set a n ew r eco rd . Th e entire
trend seems to b e a co·ntinual rise at a
very satisfactory rate.
Hea dphones Win Design Award. Among
the top five "award s of excell e nce" of this
year's d esign compe tition h e ld in co njun c t ion w i th WESCON, t h e Clevite Bru sh
Model ED- 30 0 h eadph on e. were cited fo r
Hease of a djustm e nt, perfo rnla n ce, a nd
si mplicity of co n stru c tion ." The principa l
criterion of the compe tition is "produ ct
acceptan ce thro u g h indu stri a l design ."
Fisher Plans Plant Expansion. At the
twenty- fifth a nnive r sary dinn e r of Fishe r
R a dio Corporatio n , Avery F is h e r a nnoun ce d a mas s iv e exp a nsion pro g r a m.
Th e plans called for t h e constru ction of
52,00 0 sq u are feet of a ddition a l man u fac turing s p ace to the IVIil r oy, Pen n s y lv a nia ,
facility. Existing space is 62,000 s quare
fee t , which brings the proj ected tota l to
114,000 squ a re feet. At th e same t ime, Mr.
Fisher a lso reported a pla nned d oublin g
of the firm' s advertising budge t for the
fo rthcoming year. Th e same pla ns w e r e
a nn o un ced October 16 a t a second 25th a nnive r sary dinn er h osted by Fis her rep
Charles Lienau.
Miracord Distributor Moves to Westbury.
Benja min E lectr on ic Sound Corporation,
United States distributor fo r !VIiracord, is
n ow lo cated a t 8 0 Swai m Street, in Westbury, L. I., where oper ations will be
h o u sed in a n a i r -conditioned building with
more th a n 10,000 squa r e feet of space . Accord ing to Mr . B enja min, the move w a s
n e cessary in order t o accommoda te the exp a nded sales of their produ ct an d in an tic ipation of new produc t lin es.
HIGH FIDELITY SPEAKERS REPAIRED
AMP RITE SPEAKER SERVICE
168 'vV 23rd St New York 11 N Y
.
CH 3-4812
, . .
ENJOY PLEASANT SURPRISES? Then
write us befo .·e yo u purchase any hi-fi. You 'll
be glad you did . Unu sua l sa vings. Key E lectronics, 1 20 Libe r ty St., N ew York 6, N. Y.
CLove rda le 8- 428 .
'YRITE for qu o tat ion on co mpon en ts, r eco rder s. FREE cata log. IU-FIDELI'rY SUPPLY, 2817-VC Third Ave., New York 55, N. Y.
SALE
ITElI'lS-ta pes-packn ge
Bayla , B ox 131-0, Wantagh , N. Y.
quo tes.
LP RECORDS FROM YOUR TAPE, 40 min u tes, $6.00, p.p. Wr ite for quantity pr ice . .
Qu ick sen-i ce. Custom Hecor d ill g , 92 3 Kan sa s
A ,·e., Kansa s City, Kansas.
WANTE D: 1 % and 3% ips , 'h- trll ck mono
reco rd e r. Ampex or s imil a r professional mllchine. E . R Davison , 1 35 N. Illinois, Sprin gfi eld, Illinois .
PROFESSIONAL HECORDING
EQUIPl\IENT : 2 E lect r o-Voi ce 667. 3 EV 66G. 2
Ph ilips EL6040; 2 B erlant 315 Mixer s, 50ohm inpu t, 600-o h m output ; Concertone 22ST
r ecorder. F. K enny, 1 322 Troy St., Da.Yton 4,
Ohio.
CUSTOM AUDIO COMPONENTS bu il t to
your s pecification s. Call 212 P I 1-4638 after
6 P. M.
RCA 10-watt a mplifier, Model SP-10 (MI12190) , very low distort ion, brand Dew with
manu a ls. $50 or best offer. H eath W-5M 30watt pow er a mplifier, new tran sform ers, perfect condition , wired professionally. $5 0 or
best offer. A. Hawkes, 10 Hard y Hoad, 'Vestbl'oo k , l'Iain e.
WORLD' S ONLY Fl\l/AM/MB auto radio
with AFC. Com plete with face plate for cu stom in stallati on fo r your mod el car. 10 % di scount on m a il order . Write Associated Importer' , 1168 Battery Street, SUD Franc isco
II , Calif o rnia.
FOR SALE: Two SONY C37A conde nse r
microphone systems, two Telefu nken 251E
co nde nse r microphone systems, new Grampi a n type C, n o n-fee dback c u tte rh ead, n ew
Ampex
4- c h a nn e l
monophonic
mixe r,
Ampex 692 speaker amplifier, Dyna ldt
monop h o nic pre -a mplifi e r, n ew Stevens
speaker sy stem. D a vid H e rsk, 1501 N.
N e,v to n, ~inneapolis, Millne.
each
SAVE YOUR
COPIES OF
AUDIO
• Each file holds a
full year's copies.
• Jesse Jones Vol-
ume Files for every
publication.
• Covered in durable
leather like Kivar,
tilla embossed in 16
Kt gold.
Salis/aellon guaranleed
FREE
AUDIO
Attractive and
practical for your
home or office
3 for $7.00
6 for $13,00
ORDER NOW -
send
check or money order
MAGAZINE FILE CO.
520 FIFTH AVENUE
NEW YORK 36, N"'. Y.
DESCRIPTIVE FOLDER
UPON
REQUEST
•
NOVEMBER, 1962
EDITOR'S REVIEW
(ll'om page 18 )
THE FINEST OF ITS KIND • • •
Get more FM stations with the world 's most
powerful fM Yogi Antenna systems .
To be fully informed.
send 30¢ for book
"Theme And Varia ·
tions" by L. F 8. Carini
and containing FM
Station Directory.
APPARATUS DEVELOPMENT CO.
WETHERSFIELD 9,
CONN
CIRCLE 93C
compOllcntg ai' tape reco rdcl's until yOIl get
return llIail Quotation. *gasy-Pny-Plan. · 15
trial. - Trades accepted. · We guarantee not
so ld. Best Buy Hi-Fi List and Stereo 'rape
ollr low. low
day free hO llle
to be UnderCatalog Free.
ELECTRONIC WORLD HI·FI RECORDING TAPE
, guaranteed lst qualitv .
3-23
24 +
600' M)'I.r
1.09
.99
1.200 ' Acetate
1.09
.99
7"
12 00' Myla r
1. 19
1.09
I BM
7"
1S00 ' ?!i)'lar
L SD
1. 79
2 4M
7"
2400' Mylar
2.59
2.39
24M'I'
7"
2400 ' ] '0 11 .
2.89
2.79
An y Asst. IlCl'mittcd for 24 + JJrice. Add 15 ¢ PCI' I'cel
postage & ha lidli ng- lO ¢ 24 + Conti nental U.S. A. Wri te
fo r cOlliplete listing & 100 +
prices. We ship t hrough ell tire worl d.
35.\ !
~i ~~ "
12A
12M
7"
(CONTINUED ON PAGE 98)
The above informative legend appeared a t the bottom of page 60 in the
October issue, thus indicating that the
ar ticle "Accent on beauty" would continue on page 98. Of course we forgot
to mention which issue we had in mind;
we obviously didn't mean the October
issue. For those r eader s who l'llight be
curious as to how the article ends (Does
the headphone plug go into jack A or
B W I s it tru e th at the photograph r ecords are stored in th e First National
Bank next to the mortgage for the equipment 7) we concluded the story in this
is. 'ue on page 4. W e were going to wait
until the next time we had a page 98
available but decided against it when we
got the monthly bill f or storage of the
typ e.
WHEN YOU PURCHASE
The SHERWOOD 5-3000 IV
FM/ MX STEREO TUNER
with "Aero-beam" Tuning
Features 7" expanded slide-rule tuning scale, Automatic Frequency Scale, special inter-channel hush
system which eliminates noisy "hash" between FM
channels.
TRADE 4 WAYS
• TRADE Hi-fi for hi-fi
• TRADE Amateur radio* fOr hi·fi
• TRADE Hi-fi for amateur radio
• TRADE Amateur radio* for amateur radio"
" Includes HAM ; SWL; Citizen's Band ; Test Equipment
AUDIO EXCHANGE EXCLUSIVES:
Trade·Back Plan • New Equipment from over 100
manufacturers • Used Equipment sold on 10·day un·
conditional money·back guarantee .. . plus gO·day servo
ice warranty. Special GE credit plan. custom Instal·
lation for stereo and monaural equipment. • Hi Fi
service laboratory.
~
Get more! Pay less when you trade at ~
audio exchange
For Trading info., write dept. AN.
PLEASE MAil ALL ORDERS AND INQUIRIES TO JAMAICA
153·21 Hillside Ave .• Jamaica 32, N. Y.
WHITE PLAINS, N. Y.
1797-U First Ave.
N. Y. 28 , N. Y.
CIRCLE 930
CIRCLE 93C
CANADA
GIVE YOUR RECORDS A CLEAN·SWEEP TODAY
CtRCLE 93E
High Fidelity Equipment
Complete lines~......;._....;;.Compiete Service
Hi-Fi Records - Components
and Accessories
BLECTRO~UOICE
SOUND SYSTEMS
126 DUNDAS ST . WEST. TORONTO. CANADA
CIRCLE 93H
TOPS
IN
HI-FI!
BRITISH EQUIPMENT from the United Kingdom
Hi-Fi Mail Order Specialists.
Send us details of your needs!
• AMPLIFIERS· MOTORS. TUNERS
• SPEAKERS. PICK-UPS
All goods carefully packed, insured and
shipped promptly at minimum cost.
•
C. C. GOODWIN (SALES) LTD. (Dept. A)
7, The Bdwy., Wood Green, London, N.22., Eng.
by NOT'man II. Cro'Whurst.
FM STEREO MULTIPLEXING " .•. a detailed description of the fCC standards for fM stereo broad ..
casting. _ ."-ELECTRONIC 'VORLD . .#282. $1.50.
STEREOPHONIC SOUND (2nd Ed.)" ... valuable to
those who like their 'fid elity' high and 'realistic' "
ELECTRONICS WORLD . Jl209 , $2.90.
BASIC AUDIO, 3-VOLUME LEARN BY PICTURES
COURSE" • •• experimenters and more experienced
hobbyists will find no other syllabus more richly
Informative or authoritative." HIGH FIDELITY
:MAGAZI NE . 3 vols., soft covers, #201, $8.70; clot h,
#20 1-H . $9.95.
by Her'm an Burstein
GETTING THE MOST OUT OF YOUR TAPE RECORDER
" ••• Written for the users of tape recorders, in
his language
Indeed: a contribution to 'he audi~
field." - DESI GN N EWS . '0 251. $4.25 .
FUNDAMENTALS OF HIGH FIDELITY. T ells you how
to select t he best equipmen t for the m oney and
ac h ieve th e best performan ce fro m it. #226, $2.95 •
oJ '
J/
HARPSICHORD
J/
In kit form fo r home
works h op assembl y $150
REPAIRING HI-FI SYSTEMS by David Fide/Illan .
FIDE LIT Y MAGAZ I NE. 1I~0 5,
CIRCLE 93F
AUDIO
•
NOVEMBER, 1962
Dept. R
115 Christopher St.
New York 14, N. Y.
CIRCLE 93L
$3.90.
10 DAY MONEY BACK GUARANTEE
JOHN E. RIDER PUBLISHER INC.
A division of Hayden Publi shing Co., Inc. A-11 .
116 West 14th St., New York 11, N. Y.
Enclosed is $
. Please send:
11282, $1.50 0 11209, $2.90
#201,1$8.70 0 11201.H,$9.95
02 51 , $4.250 #226, $2.95 0 11205, $3 .90
o
CLAVICHORD KIT $100
Write fOl' f"ee brochure
ZUCKER MANN HARPSICHORDS
•
Save mon ey ! "Deals authoritatively • .. with fest
gear and ,echnlquesr the major troubles encountered in various system components." HIGH
Specializes in SAVING YOU MONEY
We are FRANCHISED for most Hi·FI lines.
Orders SHIPPED PROMPTLY from our large
stock.
RECORDING TAPE
at
LOWEST
PRICES. FREE STEREO CATALOG.
715.A Second Ave. (38th
St.), New York 16, N. Y. Visit Our Showroom
AXtel 7·7577
the experts help you
get the most out of hi-fi
CIRCLE 93K
FACTORY FRESH COMPONENTS
LOWEST POSSIBLE QUOTATIONS
"FAST DELIVERY
•
MANHASSET, N. Y.
CROWHURST
BURSTEIN
FIDELMAN
---- -------------------------
"Here's a brush that cove rs the entire
tracking surface of your records. Designed
especially for manual operaf'ing turn·
tobles, turns out of the way for automatic operation. Made of MACHINED
ALUMINUM with a LARGE CAMEL'S HAIR
BRUSH that will last the life of your t urn·
table. After several revolutions of the
record, you will notice an improvement in
sound caused by the removal of dust
particles from the playing surface. This
is not a toy, but a fine piece of equipment with quality and service built into
every inch. Makes a PERFECT GIFT. ONLY
$4.95 (postpaid). Send check or money
order to PRECISION MANUFACTURING
CO., BOX 232, AURORA, INDIANA.
BROOKLYN, N. Y.
203 Mamaroneck Ave. 1065 Flatbush Ave. 451 Plandome Rd.
CIRCLE 93A
o
o
J
I
I
Name
I
I
I
I
Address
L~~ ___ -.:o~-=~:.... ____ l
CIRCLE 93B
93
ADVERTISING
INDEX
•
Acoustic Research, Inc. ...• . •• • ... . .•
AJrex Radio Corporation •••...•••... .
Allied Radio Corporation .•.. .• ... . 53,
Altec Lansing Corporation •.... .. .. 13,
Ampex Corporation •• ...• .. .. .... 29,
Apparatus Development Co. ....... .. ••
Argos Products Company •. ... . ... .. . .
Audio Bookshelf .• •... . .....• • ••....
Audio Dynamics Corporation .. .. .. 38,
Audio Exchange ..•• . . . ... .. ..••••..
Audio Fidelity Records . . .. . ... • . . . ..•
Audio Unlimited ••.• ••••... . .. .. .. ..
49
92
54
15
31
93
88
60
39
93
71
93
Barker & Williamson, Inc....... ..• ...
Bell Telephone Laboratories . .... ..••• .
Benjamin Electronic Sound Corp. . . ..••
Bozak ..••. . . . . .••.... . . ••.••.•... .
British Industries Corporation ..•. ...•.
84
20
51
73
3
Carston Studios • • .. . .. ..•........•• 93
Classified . . .... .. . .... ... ..••...•.. 92
Concord Electronics Corporation .... .. . 94
Dynaco, Inc. •••• ••. ....••• . ....•... 81
Eastman Kodak Company •. ......... .. 7
EICO ... .... ....... .... ........ . .. 11
Electronics Applications, Inc.. .... •... _ -'1-8
Electro-Voice, Inc .........•.••.. Cov. IV
Electro-Voice Sound Systems .......... 93
EMI ..••• . • . . . .•..• .•• . ........... 63
Empire Scientific Corporation ..•• •. Cov. II
to make professional quality stereo
tape recordings your recorder must
have ~
three heads
All professional tape recorders have three separate heads-one erase,
one record, one playback. Record heads and playback heads have different
gap widths. A wide gap record head is a must to record all the sound on the
tape. A narrow gap playback head is a must to reproduce all the sound from
the tape. Professional quality sound on sound recordings can be made only
on a recorder with three heads.
The Concord 880 was designed for Connoisseurs of fine music-for
those who want to hear and appreciate the difference between ordinary
tape recordings and the fine professional recording and sound reproduction
of the Concord 880.
Other important professional features of the Concord 880 include:
• all push button operation
.4-track stereo record-playback
• new varisync flutter free
salient pole drive motor
• sound with sound recording
• exclusive Concord computerized
channel indicator
• three speeds
• built in monitoring
• dual full range speakers
.10 watt dual amplifier
• dual cathode follower high
impedance outputs
The 880 includes two professional dynamic microphones in a compact unit
perfect for use as a portable stereo recording and playback system-ideal
as a permanent part of your hi-fidelity music system.
Compare the Concord 880 and see why it offers much morein performance-in features-in reliability-in value.
Make a recording quality comparison test at your dealersif you're a connoisseur you'll hear the difference.
If you'd like a copy of Concord's booklet, "All the Facts"
send lO¢ to Concord Electronics Corporation
The best value in Stereo Tape Recorders-under $400.00
CONCORD
880
--:l
CONCORD ELECTRONICS CORPORATION
Fairchild Recording Equipment Corp. . ., 6
Fidelitone . .•. •. . . .. . .. .... . . . . . . . . . 92
Finney Company • ••.. .••..• .. .. ... .. 91
Fisher Radio Corporation ........ ..... 9
Garrard Sales Corp. ....•••••....•.... 3
Goodwin, C. C. (Sales) Ltd...••.. • .••. 93
Gotham Audio Corporation ••• • ....••.. 72
Grado Laboratories. Inc...••• .... .. . •. 87
Grommes, Division of PreCision
Electron ics, Inc. •.•.....••......•.
4
Ha rman-Kardon .. ... •..••.. . . . :.. 33-36
Heath Company .•••.. ... ..... .. . 16, 17
Hi Fidelity Center .. ... .•. •.. . ... . . .. 93
International Electroacoustics Incorporated
90
Jensen Manufacturing Co. ..•••... . ... 57
Kenwood Electronics Company •••..... 14
Key Electronics Company . • ... . . .. ...• 91
Koss Electronics, Inc . ••••• •. . ..• ... .. 74
La fayette Radio .• . .•• • •• • • . . •• .. ... . 86
Lansing, James B. Sound, Inc• •• •• ••• .. 67
Magnecord Sales Department, Midwestern
Instruments, Inc. ......... . ....... 84
3M Company .. .. •••.•••• .... .... .. . 59
Neat Onkyo Denki Co. , Ltd. .• ••..... . . 12
North American Philips Co., Inc ••. ••. . . 89
Pickering & Company, Inc •• • . .... ... .
Pilot Radio Corporation ••.•.• • ... • ...
Pioneer . .....•. • . .. . ••••••.••.... . .
Precision Manufacturing Co. . ..••. .' . . .
19
41
77
93
Reeves Soundcraft Corp. •••••• • • •.....
Rek-O-Kut Co., Inc . . . .....••••. . ....
Rider, John F., Publisher, Inc.... •... . .
Rockford Special Furniture Co . •.•...••
27
86
93
75
Sarkes Tarzian, Inc. . .••• •. ...• •. ....
Scott, H. H.• Inc.... .. . •••.......... .
Schober Organ Corporation .. ... ... .. ..
Sherwood Electronic Laboratories, Inc. ..
Shure Brothers, Inc.•••••••.•.••. Cov.
Sonotone Cartridges ....... . .........
Sonovox Co. , Ltd. •••••• .. ...... ••...
Stackpole Carbon Company .. . .... ....
Superscope, Inc. ..•••••••••••.......
65
83
79
1
'"
85
90
80
5
Technical Appliance Corporation •••••.. 90
Telefunken . .•••••••.........•••• . . 91
Thorens Division, Elpa Marketing
Industries, Inc. • •••.•••••. . ....... 47
University Loudspeakers •• • •', . . . . . 43, 45
Weathers Division of Teleprompter .. ... 69
Winegard Antenna Systems .... .. . .... 2
Z uckermann Harpsichords • .•.•. ...... 93
809 North Cahuenga Boulevard, Dept. L, Los Angeles 38, California
94
AUDIO
•
NOVEMBER, 1962
the ultimate in sound reproducers
SHURE
STUDIO
I
MODEL M222 and M226 integrated tone arm and cartridge
.. . cannot scratch records . .. tracks at
3/4
grams
• Unapproachable for record protection and
sound quality
• Cannot scratch records-even if "dragged"
across grooves
• 'Ultra-light, flawless tracking-even if table
is tilted!
• New"plug-in" cables for easiest mounting
-no soldering
The Shure Studio Dynetic integrated tone
arm and cartridge has long been recognized
as a unique contribution to highest fidelity
coupled with unparalleled record protection. The new Model M222 and M226
Studio Stereo Dynetic arm is significantly
improved in many important respects at
no increase in price: tracking force has
been lowered to an ultra-light % to 11/2
grams. Compli ance is an astounding 22 x
1O-6 cm . per dyne! New plug-in cable makes
for easy, solderless mounting. Precision
.0005" diamond tip.
The Studio Stereo Dynetic arm's noscratch feature has been the talk of every
hi fi show since its introduction-does
away with the major cause of ruined records once and for all. Has actually been
artificially stopped in tests to "skip" back
and play the same groove over and over
many thousands of times without audible
damage to the groove.
Out-front needle makes it ideal for music
lovers to "index" records. Instantly changeable stylus requires no tools.
Model M222 for 12" records, Model
M226 for 16" records. Complete assembly
includes Arm, Cartridge, Stylus, Plug-in
Cable_ $89.50 net each.
SPECIFICATIONS FOR MODELS M222 and M226
TRACKING FORCE
14 to 1.5 grams
FREQUENCY RESPONSE
CHANNEL SEPARATION AT 1000 cps
SENSITIVITY: OUTPUT AT 1000 cps
20 to 20,000 cps without "break-up"
Over 22.5 db
4.5 mv per channel
RECOMMENDED LOAD IMPEDANCE
COMPLIANCE (VERTICAL & LATERAL)
INDUCTANCE
D. C. RESI STANCE
STYLUS
47,000 ohms per channel
22.0 x 10-6 em per dyne
400 millihenrys
600 ohms
.0005" diamond
LITERATURE: SHURE BROTHERS, INC . 222 Hartrey Ave., Evanston, Illinois, DEPT. A-K
to provide the biggest sound in slim-lines!
New
Electro-Voice
REGINA
200
Now! Enjoy a slim-line system that sounds
as good as it looks! The new E-V Regina 200
with component-quality' speakers expressly
designed to meet the challenge of ultra-thin
cabinetry!
In the woofer, fo r example, where some
thin-speaker systems use light-weight "radio
set" speakers, the new E- V Regina 200 employs a true J O-inch high fidelity speaker ...
with powerful Jib. 6 oz. ceramic magnet,
precision edgewise-wound voice coil and
specially-tailored low-resonance suspension.
This combination guarantees solid response
to 50 cps, plus minimum distortion and
optimum efficiency - with even the lowestpowered stereo amp lifiers!
Now, examine the tweeter! It has the look
and sound of fine laboratory equipment!
The heavy die-cast frame and jewel-like
machining insures a lifetime of uniform
response. And note the polyurethane suspension system that's years ahead of the
rest! It's the secret of the ~emarkably smooth
response to 15,000 cps! Note the handy
level control on the back of the Regina 200
for exact personal control of tonal balance.
Measuring only 5-5/8 inches deep, 24-3/ 8
inches high, 16-3/ 8 inches wide, the new E-V
Regina is a beautifully easy answer to your
stereo speaker placement problems. And it's
easy on the pocketbook, too ... just $89.50
net with oiled walnut finish.
.
Hear the biggest sound in slim-lines ... the
new Electro-Voice Regina 200 at your E-V
dealer's today!
ELECTRO-VOICE, INC.
Con sumer Products Division
Dept. 1124A, Buchanan, Michigan
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