Sept - American Radio History
xay:yurz
a,44./
000
as the
whisper
of
a
butterfly's
wing...
because low noise and low hum are essential to hi -fi preamplifier performance, designers specify twin- triode
RCA -7025
The grace, lightness, and delicacy of the butterfly in flight seem to capture the mood of quietude so essential, so sought after by
designers and by devotees of high -fidelity music reproduction.
Developed for high -gain, resistance -coupled "preamp" applications, high -mu twin -triode RCA -7025 is specially controlled
for low noise and hum. A helical hairpin -type heater in each unit minimizes hum. In addition, RCA -7025 has an exceptionally
sturdy cage assembly featuring short, stiff stem leads, oversized side -rods and micas of special design to reduce noise and
microphonics.
You can fulfill the important requirements for a "quiet" preamplifier by designing around RCA -7025. Your RCA Field
Representative has full information. For Technical Data, write RCA Commercial Engineering, Section I-91-DE, Harrison,
New Jersey.
ANOTHER WAY RCA SERVES YOU
THROUGH
ELECTRONICS
RADIO CORPORATION OF AMERICA
Harrison, N. J.
Electron Tube Division
R C A
T
U B E S
F O R
H
I
- F
I
A L S O
A V A
I
L A B L E
AT
Y O U R
www.americanradiohistory.com
AmericanRadioHistory.Com
EAST: 744 Broad St., Newark 2, New Jersey,
HUmboldt 5 -3900
MIDWEST: Suite1154, Merchandise Mart Plaza,
Chicago 54, III., WHitehall 4 -2900
WEST: 6355 East Washington Boulevard. Los
Angeles 22, Calif., RAymond 3 -8361
R C
A
T U B
E
D
I
S T R
I
B U T O R
SEPTEMBER, 1959
VOL. 43, No. 9
',aeeessor to RADIO, Est. 1917.
Discover for yourself why Sherwood
is the most honored line of high fidelity components in the field. Sherwood
Tuners (the first ever to achieve sensitivity under 0.95 microvolts) feature:
Inter -Channel Hush, a noise muting
system which makes FM tuning easier
than ever
FM Multiplex Output
"Feather -Ray" Tuning Eye
Automatic
Frequency Control
Flywheel Tuning.
Combine these tuners with either of
Sherwood's "mated" stereo amplifier
AUDIO
ENGINEERING
MUSIC SOUND REPRODUCTION
choices; 20+20 watts or 36+36
C. G. McProud,
watts. And only Sherwood offers all
these features: Single /Dual Bass &
Treble Controls
Mid -Range Presence
Rise
Stereo-Mono Function Indicator
Lights
Phase -Reverse Switch
Damping Factor selection. Sherwood
also offers either 36 or 60 watt monaural amplifiers, FM Multiplex Adapters
and a complete decorator -styled line of
cabinetry and 3 -way speaker systems
The Finest in High Fidelity. Sherwood
Electronic Laboratories, Inc., 4300 N.
California Avenue, Chicago 18, Illinois.
Editor and Publisher
Henry A. Schober, Business Manager
Harrie K. Richardson, Associate Editor
Linda Sueskind, Assistant Editor
Janet M. Durgin, Production Manager
Edgar E. Newman, Circulation Director
-
Sanford L. Cahn, Advertising Director
-
MEMgER
ty,1111,1/1
Midwest Representative
W. A. Cook and Associates
161 East Grand Ave., Chicago 11, 111.
West Coast Representative
James C. Galloway
6535 Wilshire Boulevard, Los Angeles 48, Calif.
01
Model S- 5000.20
-
+ 20W
Stereo Dual Amplifier
'-©l
Model
CONTENTS
S -3000
$169.50
ee
:
`
H, FM Tuner -5105.50
alilikoreammtieleutat
.ludiocliltie-.Tacrph Ginrunelli
Audio Tecluli(Ines-Joseph (:io rvnuclli
Lettety
Audio ETC-Edward Tuloui! Cu
(i
Model
I O
Stereo Preamp. + 36W Amp. S159.50
12
Editor's Report
Low -Noise AAI Tuner
S -4400,
1(i
I -SOS
Ti1)111'
1111)ut-
( /,sirle.. II. ('lrinldl -r and _I//en If. (ireeraleuf
for All-Edwin F. 11
Contributory Infringement of Patents- Albert Wow/rag' Gray
19
All For Unte, Unte
Model S -2000 H, FM -AM Tuner
$145.50
'31
24
?-
What About Stereo Multiplexing and _AIatriaing
A7urnuarl II. Crulallmrwt
29
Tape Guide- Ineorporatint; Tape into the Andio System-Herman Bnì. te in :32
A 'l'en- Watt All-Triode Amplifier- Hubert 31. Voss and Robert Klli.
40
A 'Panphouie" Stereo Control Amplifier- George t3ltuzniul; Letri.s
44
Equipment Profile
/(l SP-.216-_,1 stereo preamp- control Inuit; ('uirersit2l
T31S -2 Trimen.iuuul .stereo speaker; the Leak amplifier line; Dynaco
Stereo 70 poorer amplifier bit
45
.Jazz and All That-Charles -I. liuberl..rua
56
Record Revue-Edward Tatnull Canby
66
Product Preview
69
Model S -1000 II, 36W Monaural Amplifier $109 50
only for those who want the ultimate:
-Pi
('oiling Ili -h'i Shows
STEREO
S:1
AES Convention-List of Papers
Who's the first. AUD1OUAN'.r
S4
93
Errata(
Industry Notes & People
Advertising Indes __._
9S
___
_
__.
99
_
1011
COVER PHOTO-Tiro of the element.. of a Lowe installation designed and built
William G. 1)illey-, Audio -Architectural Consultant, of San Bernardino, California. Lys
the left is a combination end table, coffee table, and TV remote control housing; At
the
unit :It the right is ono of two fobled horn enclosures in his living room. This
installation will be elaborated upon in the October issue. Photo by Dick .Zones, San Bernardino.
AUDIO (title registered U. S. Pat. Oft t is published monthly by Radio Magazines,
Inc., Henry A. Schober, President;
C. G. Metroud, Secretary. Executive and Editorial Offices, 204 Front St., Mineola,
N. Y. Subscription rates
S.
Po®easlons, Canada and Mexico, $4.00 for one year. 57.00 for two years, all other
countries, $5.00 per year.
-U.
Single
copies 500. Printed in U.S.A. at Lancaster, Pa. All rights reserved. Entire contents copyrighted
Inc. Entered as Second Class Matter February 9, 1950 at the Post Office, Lancaster. Pa. under 1959 by Radio Magazines,
the act of March 3, 1879.
RADIO MAGAZINES, INC., P. O. Box 629, MINEOLA, N. Y.
Postmaster: Send Form 3579 to AUDIO, P. O. Box 629, Mineola, N. Y.
AUDIO
For complete technical details write Dept.
A -9,
SEPTEMBER, 1959
1
www.americanradiohistory.com
AmericanRadioHistory.Com
\1
.
01%'t
.C
AU 010clinic
JOSEPH
GIOyANELLl:_
phonic 'sonWI I srvitcched front a Pilot to
an Eico FM Inner with no apparent change
in the recept ion of the ignition interference.
mg antenna is a non -directional folded
dipole, mounted approximately o'8 feet
above n'ri roof and about 45 feet above
grossed level. It is set back about 40 feet
from the street. Lead -in wire i.e twisted and
is about 45 feet long. The strength of the
received .signal seems to Quake little or no
difference, because it seems that the intensity of the interference is about the some
on all stations. Can you offer any suggestions ass to what I can do about this problem? U. L. McCain, Belmont, Calif.
A. The first thing which cones to mind
with regard to ignition noise is. "Flow
much signal strength is available at your
location ?" If signals are below the limiter
threshold, there is little you can do.
If, however, some of the noise is pieked
up b:- the lead -in, you might be able to do
something after all. Replace your present
lead-in with 31)0 -ohm shielded line. It is
similar in idea to two -conductor shielded
A Single Amplifier and Two Speakers
NOT FOR EVERYONE
...perhaps for
you
Q. I hare a Bogen D1',2ODF 20-watt amplifier and two Jim La n. sing D -1.;!3 76 -ohm
speakers in reflex enclosures. 111/ desire is
to hook up these speakers so that I n ay
lise a 3- position switch and plan either One
or both as desired. The Bogen. asepli er
has common, 8 -ohm, and 16 -ohm out ut
conections.
11ill you please .shore me the pro et/lookup to the amplifier u-hen using b th
speakers as mentioned? Earle R. 1Vieklr m,
Bloomingdale, 'i'..1.
A. Figure 1 shows a circuit which, when
constructed, will function as you desire. No
further explanation need lie given.
FM and Ignition Noise
Q. My FM ants eiia picks up ignit'osi
noise from passing cars, presumably frni
those which do not hare suppressors. In
converting from osionophunic to star,,,.
*
342li Seivkirk Are., Brooklyn
.
-.
\
1.
3- SPEED, 4 -TRACK
STEREO RECORDER
PLAYBACK
I
Tandberg 5 is not everyman's
tape recorder. It is an instrument
built to incredibly rigid standards of
perfection, designed to provide the
discriminating listener with a lifetime of listening pleasure. To the
educated car, the difference between Tandberg reproduction and
conventional recorder playback is
immediately apparent.
Yet, the difference is subtle. It is rcfleeted in shadings and nuances that
most recorders ignore. If your ear is
finely attuned to musical perfection
if you relish the certainty that
you own the finest . . . then the
Tandberg 5 will give you more
pleasure -per -dollar than any other
tape recorder, anywhere.
'I'lAc
o
A
16
Li
TAP
-o\
O
B
...
See
and
hear the
Tandberg
5
8,, TAP
o
o
o
O
16
VVVVVb
16
WVW
at your high
POS
POS
POS
POS
POS
POS
POS
POS
instrument illustrated here
is the Tandberg Model 5 -2. Complete with two
TM -2 microphones for home stereophonic recordings, input- output cords, reels and handsome Transport luggage case, $513.95. Other
Tandberg models from $249.50.
For full information, write Dept. A9.
fidelity dealer.
The
Tandberg
8 Third Avenue
of America, Inc.
Pelham, New York
-A FEEDS A', FEEDS B' (STEREO)
-A FEEDS A', B' SILENT
-8 FEEDS B', A' SILENT
4 -A
FEEDS A' (STEREO INVERTED)
B',
B', A' SILENT
-A
6 -B FEEDS A', B' SILENT
-A
A' AND B'
B
I
2
3
FEEDS
FEEDS
5
7
8
-B
B
FEEDS
FEEDS
A' AND B'
Fig. 1.
AUDIO
2
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
"Without reservation we recommend the Garrard Changer
with the Pickering Fluxvalve Cartridge for stereo records.
We believe more Fluxvalves are in Garrard Changers than
in all other turntables and changers combined,"
says
President, Pickering and Co. Inc.
"We can readily
understand the
public confidence
in Garrard Changers
for Stereo,"
.11 r. James E. Fox,
Seerice Manager,
Pickering and Co. Inc.
saf /s
Stanton
Stereo
FLUX VALVE
Model 37Mounted in
Garrard
Shell
Our own laboratory tests as well as
service records show that Garrard
changers are virtually trouble -free and
require no taljustrnent for perfect stereo.
-
reproduction with a Pickering cartridge.
The design and precision mounting of
the Garrard changer tone arm make
it eminently compatible with the Fluxvalve principle. In fact, we have used the
Garrard changer in the development
of all Pickering stereophonic and
monophonic cartridges for many years. '
We thank Mr. Stanton and Mr. Fox for these personal
comments which explain why so many discriminating
high fidelity enthusiasts are completely satisfied owners
of Garrard Changers with Pickering Stereo Cartridges.
Today, more Garrard Changers are sold as components
for stereo than all other turntables and changers combined.
Here are the reasons why Garrard Changers are
endorsed for stereo not only by Pickering, but by
all other manufacturers of fine stereo cartridges
Electro- Voice, Shure, General Electric, Fairchild, etc.
-
For the best in Stereo...
Insist on a
Vibration -free turntable.
Vertical and lateral rumble completely inaudible. Wow
z nd flutter far below exacting "broadcast tolerance" standares.
Exclusive Aluminum tone arm precision -mounted at
engineering works for optimum tracking angle, perfect sound
reproduction.
Unrestricted choice of stereo cartridges -any of them will
track at the manuf:.cturer's lightest specified weight.
CHANGER
Lecord handling gentler than the surest human hand.
'the important convenience of manual play plus completely
automatic operation without compromise in performance.
THE WORLD'S FINEST!
These are the FACTS, no one can deny them with
authority -and they are backed by the 36 years of
experience that have created Garrard's unique
Send for free Garrard Comparator Guide.
Your Name
reputation fer u;tsurpassed quality.
Address
State_
City
Tati
t
a
Garrard for
dality
systi1F!
trC]ta/nl
towe
manor
9lZSa
'rt+y
W
°
.
all
std/l`'._
Mail to Dept.GM -19 at adduces below.
and vi
ttiVtt
tar
%18.0
76r
tR
/N
i
1"."1:4,
WY
Sft,g6
GARRARD SALES CORPORATION, Division of British Industries Corporation, PORT WASHINGTON,
N. T.
Canadian inewirier to Choi. W. Pointer, Ltd., d Aldno Awn., Toronto
Territories achar thon U.S.A. and Canada ts Garrard Enpineerints b Mt¢ Co., ltd., Swlndoa, Wilts.,
Engkvrd
line such as that used with low -impedance
balanced lines. Do not use ordinary cable,
since the capacitance will not be correct.
The two leads of the line are connected to
the input terminals of the FM set, and the
shield is grounded to a radiator or wa'terpipe.
If you still have excessive noise pickup,
you will then need to do one of three
things : 1) Use an antenna having higher
gain; 2) use an FM receiver having a lower
limiter threshold; or 3) mount the antenna
even higher than it now is. You may have
to resort to a combination of all three possi-
You
Say
AUDIO
Is
bilities.
Publishing
A
Cookbook?
-
Yes, AUDIO is publishing a cookbook
not that we intend to extend the subject
of gastronomy to include recipes in future pages of AUDIO.
You may ask ...why?
And we would answer Simply because
we feel that people who read AUDIO,
and enjoy the finest quality music reproduction also enjoy really good food on
-
push himself away from the table before
upsetting the..daily calorie count."
Here is a cóokbook that will enable you
to recreate in your own homes superb
dishes experienced Only at the Mirror
Lake Inn -dishes like.Lake Trout Baked
In Wine and Adirondicck Apple Pie, recipes for which are reproduced below
-
LAKE TROUT BAKED IN WHITE WINE
Remove heads and tails froth a 2-pound fish. Split open down
their tables.
back and rinse well. Remove backbone and rub inside with lemon,
Your next question may be...Is it a dif- salt, pepper and thyme to. taste. Knead tablespoon of butter
and anchovy paste the size of a large pea; placing mixture inside
ferent kind of cookbook?
fab. Place fish in a greased baking pan and cover with r4 cup
Of course our reply would be -Yes! Oh, of white wine. Bake 25 to 30 minutes in moderate oven, 350
Baste frequently. Garnish with parsley and lemon
it doesn't have a revolutionary format degrees.
and serve with plain boiled potatoes.
and it appears to look like any ordinary
ADIRONDACK APPLE PIE
cookbook. But, the secret of its goodness
3 tbsps. white corn syru
c. sugar
is the recipes that fill its 148 pages...
2 tbsps. sifted flour
-6 to 8 rift apples. thinly
recipes responsible for the heart warmup. grated nutmeg
sliced
ing, flavorsome, homespun aromas expe- y c. orange.juice
pastry
c. melted butter
rienced only in the kitchen of ari AdironMix together the sugar, flour, nutmeg, orange juice, corn
dack country home.
syrup and melted butter. Add the sliced apples and mix thoroughButter a pie pan heavily before putting in your pastry. Fill the
The name of the book is PLACID ly.
pie shell with the apple mixture and make pastry strips for the
EATING, and it is chock full of palate - top which should be dipped in melted butter before putting on
pie. Bake in 400 degree oven for 15 minutes: reduce het to
tempting recipes compiled by Climena the
250 degrees and bake 35 to 40 minutes longer.
M. Wikoff, owner of the Mirror Lake Inn
...at (you guessed it) Lake Placid, New This colorful book, plastic bound for easy
York.
handling, will contribute many wonderActually, the first edition (now out of ful adventures in food for everyone in
print) was discovered by Mr. AUDIO the family. Order a copy today, the Lady (C. G. McProud) during his stay at Mrs. of-the -house will adore you for it. InciWikoff's Mirror Lake Inn, where, in Mr. dentally...it makes a wonderful gift for
McProud's own words -"... every meal is anyone. PLACID EATING, 152 pages,
so tasty that eating becomes a real joy, Plastic Bound: $3.95.
where each night's dessert excels the one
from the night before, where one has to
1
I
t34
Vs
ORDER TODAY
Two Amplifiers and Two Speakers
Q. My problem, simply staled, is the following: I have two amplifiers and two
speakers. I should like to build a switching
unit enabling me to use amplifier 1 with
speaker A, speaker B or both: also, No. 2
with either or both. If possible. 7 t' ouldd like
to be able to use amplifier No. 1 with one
speaker and simultaneously, amplifier No.
2 with the other for my stereophonic sound
system. The impedance of both speakers is
16 ohms. Both amplifiers are equipped with
4 -, 8 -, and 16 -ohm outputs. Martin S.
Lubell, Pittsburgh, Pa.
A. Figure 2 meets your requirements,
with one addition. I provided a stereo
normal, and a stereo -inverted position, so
that the speakers may be reversed with
regard to the amplifier to which they are
connected. The diagram will make this arrangement clearer. Switch positions are
clearly identified as to function.
The 70 -Volt Line
Q. 11-hat are the advantages of a'70 -volt
system.? In fact, what is a 70 -volt s,>)stem?
I understand that extra long lines can be
used but I believe a matching transformer
is required at the speaker end of the line.
Will this transformer degrade the performance of the system? What if the
speaker envi of the line uses a crossover
network? What are the disadvantages of
the system? Does the 70 -volt line need
heavy wires to carry the voltage? James C.
Pale.stin, St. Louis, Mo.
A. A 70-volt line is primarily intended
for public address work. It would have no
application in the home unless the lines
running to the speaker were very long. This
(Continued on page 95)
... $3.95
Fig.
AUDIO
4
www.americanradiohistory.com
AmericanRadioHistory.Com
2.
SEPTEMBER, 1959
NEW SOUND EXCITEMENT
FOR THE HI-FI STEREO AGE!
Never before, so many quality features in
loudspeakers
yet priced for the modest
budget!
Dual cones for breathtaking wire
range performance!
Twin voice coils in 12"
loudspeakers with flexible impedances of 4,
8 or 16 ohms, enabling you to select the
impedance you require
Non -resonant cast
aluminum girder constructed frames! Fully
tropicalized for finest operation in any climate
For stereo or monaural
singly or
in matched pairs.
-
HEAVY DUTY
CAST ALUMINUM GIRDER
CONSTRUCTION
-
MAGNET ASSEMBLY
WEIGHT 61.5 OZ.
NEW! Lorenz S -1288 II
Consists of Lorenz S -1288
with twin tweeters on rigid
metal bracket and high pass
crossover. Dual cones and
voice coils with 4, 8 or 16
ohm impedances. Frequency
response: 18 to 18,000.
Power rating: 35 watts peak.
A system in itself!
$67.50
4, 8 AND 16 OHM
IMPEDANCES
NEW! Lorenz S -888
Spacious sound with real
economy! Outstanding 8"
speaker with dual cones and
high efficiency 8 ohm voice
coil. Frequency response:
30 to 14,500 cps. Power
rating: 18 watts peak. Magnet assembly weight. 28.5
oz.
$21.50
TWIN VOICE COILS
NEW! Lorenz
S -388
Armored horn -type
21/2"
tweeter with plastic cone for
120- degree high frequency
sound dispersion.
NEW! LORENZ S-1288
sealed. Frequency response:
2,000 to 18,000 cps. Impedance: 5.5 ohms.
Power rating: 2 watts peak. The perfect mate
for Lorenz 12 "or 8" speakers.
$8.50
HP -1 High Pass Crossover
Crosses over at 2,000 cps at
rate of 3 db per octave
-
Value- packed basic 12" loudspeaker with dual cones
for stereo or brilliant monaural. Twin voice coils provide 4, 8 and 16 ohm impedances
on
one speaker! Frequency response: 18 to 15,000 cps. Magnet assembly
weight: 61.5 oz. Power rating: 30 watts peak.
$44.50
NEW! OMEGA
Completely finished on four sides for
use horizontally or vertically. Inside, a
full spectrum Lorenz 12" speaker, two
tweeters and high pass crossover.
18- 18,000 cps.
16 ohms.
40 watts
peak.
27" e 143/4" x 111/2".
Unfinished Birch
Assorted Finished Woods
Jaity
AUDIO
NEW!
KAL
-AUDETTE
I
46 lbs.
$109.50
119.50
-
Compact for bookshelf or table
or attach brass legs for consolette. Houses
superb Lorenz 8" woofer, tweeter and
crossover.
35-17,000 cps.
8 ohms.
18 watts peak.
11 "z 233/4 "x 10 ".
16 lbs.
Brown or Blond Leatherette
$49.50
Matching Brass Legs
5.95
At High Fidelity Dealers Everywhere.
New fer-
rite magnet hermetically
DUAL CONES
-
feeds highs to tweeters,
lows to woofer. Extends
speaker system range to
' limit of audibility.
For use
with 2 or 3 way systems.
$4,95
NEW! AUDETTE
III
Big performance In small space! Use
singly or pair for stereo. Completely
finished on four sides for use horizontally or vertically. Features Lorenz
8" woofer with matching tweeter and
crossover.
30-17,500 cps.
8 ohms
18 watts peak.
11" x 233/4" x 10"
20 lbs.
Unfinished Birch
$57.50
Assorted Finished Woods
64.50
Matching Brass Legs
5.95
ci
NEW! AUDETTE SR.
Infinite baffle construction for
"big system" performance. Complete with 4" legs. Houses famous Lorenz 8" woofer and
tweeter with crossover.
FREE
Catalog -Write Dept.
PRODUCTS, Ltd.
514 Broadway, New York 12, N. Y.
Exclusive U. S. Distributors for Lorenz High Fidelity Loudspeakers
SEPTEMBER, 1959
www.americanradiohistory.com
AmericanRadioHistory.Com
30ohms.
20
221/4" x 221/4"
x 101/2 ".
37 lbs.
Satin Mahogany
$69.50
Blond or Walnut
74.50
17,500 cps.
watts peak.
A
WOrth 6 -0800
8
Tung -Sol audio tubes
dynamically balanced
and twin -packed
in matched pairs
by the manufacturer
r1
JOSEPH GIOVANELLI
5881
For service
in
amplifiers of up to 50
watts.
6550
For service in
amplifiers and commercial audio equipment of
up to 100 watts.
you can come as close to
N
faultless sound reproduction as the design and circuitry
oNow
of your hi -fi equipment will
permit. Tung-Sol 5881 and 6550
beam -power amplifier tubes are
dynamically balanced and factory- matched to very tight performance limits to help you
achieve lowest distortion at all
volume levels.
Use of Tung -Sol 5881 and
6550 tubes has long been associated with amplifiers of the
very finest design. These tubes
have always been produced to
closest possible tolerances with
cathode current ranges held to
an absolute minimum.
Now, in twin -packed pairs,
they assure the hi -fi enthusiast
and the commercial sound engineer of replacement tubes that
will provide new standards of
feature of
performance
-a
importance with the
special
newest amplifiers and loudspeakers, particularly binaural
sound equipment. See your
parts supplier.
Tung -Sol Electric Inc.,
Newark 4, New Jersey.
®TUN G-S O L
NOTE. Many of you have asked why this
column has not appeared 'more frequently.
The answer lies in the fact that I have not
received sufficient material to make this
column a inure frequent fealme.
I'or- thr benefit of new readers, I wish
to mention that this column is devoted to
the spreading of ideas which eon help the
experimenter. Many of you hare ()ern faced
with problems and found solutions to
them. It is more than likely that it ese
problems and their solutions will be of sen
eral interest to many readers. This column
offers the place wherein these ideas can be
made available to those who can benefit
from them. After all, it is only by sharing
experience and information that banks of
knowledge are built. It is, in fact, one of
the important means by which cirilizatiorr,
as we know it, has been brought about.
This column is actually an extension of
my other column, AuDIOCLINIC. In t rat
column, a reader's personal problems t ith
an improperly aligned tuner, for exam le,
is translated into a problems of intereso to
make an effort to
many. In that column,
solve the particular problems under discussion, whereas, in this one the reader sub mits problems and their solutions. By these
two coin?uns u'e have a means for relieving
the experhnerrter of the need to break
ground on his own which has been broken
by otlur.. prior to his coming upon the
problem. Ills wind is then free to move
onto other rrperinrenting in which he in
turn, may come up against a problem which
he may solve. His problem may then eery
well be of interest to the rest of us, relieving ass of the need to do the same work.
This is the manner by which this ban'. of
knowledge mentioned can build up.
The following is a typical solution o a
problem. Mr. Cote was confronted with the
weed for considerable inductances so ¡hat
hr could test the performances of speakers
and crossorer networks. _l.s you'll .see he
made one indnefanre .verre u. mane inductances.
I
baffle, a reflex cabinet, a labyrinth, or a
plain soapbox, varying with each enclosure.
This is one of the many intangibles
which must be taken into consideration if
optimum results are to be obtained. To
cope with this problem, the following variable inductance may be of some use in
dealing with homemade cabinets of no specific design, in a non -technical and prac-
tical manner.
Materials Needed.
3 lbs. of No 16 gunge enamelled copper
wire.
Wood winding forms.
Multi-contact switch (Mallory 3111.1 i.
1/4
HT
'---- - Fig.
1
in ding For m. A piece of brooms handle
i inch in diameter and 2 inches long will
do nicely if it is accurately cut to size.
A 14 inch hole is drilled in the center from
one end to the other. ( Fig. 1
r
t
/4"
HOLE
c
Fig.
2
Sides of Winding Form. Cut two pieces
of 1/2-inch plywood 4 inches square (i.e.,
4 inches on all sides) and drill a 14-inch
hole at dead center of both pieces. (Fill. 2)
Test Inductance for Crossover Networks
Crossover networks, the low impedance
networks located between the loudspeaker
voice coil and the amplifiers output- transformer secondary, are attenuation networks
affected by the impedance of the loud
speaker. In turn, the impedance of the
loudspeaker is affected by the type of cabinet or enclosure in which it is housed. Thus,
the impedance of the same loudspeaker will
be affected if it is mounted in an infinite
* 3420 Veewkirk Are., Brooklyn 3, V. F.
BASE
Fig. 3
('hmp these two pieces in a vise, and
with a hacksaw eut five slits in each of three
sides in a radiating pattern ending close to
(
AUDIO
6
www.americanradiohistory.com
AmericanRadioHistory.Com
Continued on
page?'
SEPTEMBER, 1959
Eais-tr-buitd,
style
performance
quality
STEREO EQUIPMENT CABINET KIT
Co3td
soul 6.44!
ri
t
MODEL SE -1 (center unit)
Sh pá. Wt. 162 lbs.
$14995
MODEL SC -1 (speaker enclosure)
Shpg. Wt. 42 lbs
$3995 each
Superbly designed cabinetry to house your complete stereo system.
Delivered with pre -cut panels to fit Heathkit AM -FM tuner (PT -I),
stereo preamplifier (SP -I & 2) and record changer (RP -3). Blank
panels also supplied to cut out for any other equipment you may now
own. Adequate space also provided for tape deck, speakers, record
storage and amplifiers. Speaker wings will hold Heathkit SS -2 or
other speaker units of similar size. Available in unfinished birch or
mahogany plywood.
MONAURAL -STEREO PREAMPLIFIER
KIT (Two Channel Mixer)
World's largest manufacturer of
electronic instruments in kit form
MODEL SP -2 ;stereo) $56.95 Shpg. Wt. 15 lbs.
MODEL SP -1 (monaural)$37.95Shpg. Wt.131bs.
MODEL C -SP -1 (converts SP -1 to SP -2) $21.95
HEATH COMPANY
Benton Harbor,
Shpg. Wt.
5
lbs.
25, Michigan
Special "building block" design allows you to
purchase instrument in monaural version and add
stereo or second channel later if desired. The SP -I
monaural preamplifier features six separate inputs
with 4 input level controls. A function selector
switch on the SP -2 provides two channel mixing.
A 20' remote balance control is provided.
[L-.$4bsidiary of Daystrom, inc.
a
HIGH FIDELITY
RECORD CHANGER KIT
MODEL RP -3
$6495
Turntable quality with fully
automatic
features! A unique "turntable pause" allows
gently into place while turntable is stopped. The tone
the motionless record, and a friction clutch assures
Automatic speed selector plays mixed 33!á and 45
regardless of sequence. Four speeds available: 16, 33'3,
45 and 78 RPM. Changer complete with GE -VR -II cartridge with
diamond LP and sapphire 78 stylus, changer base, stylus pressure
gauge and 45 RPM spindle. Shpg. Wt. 19 lbs.
record to fall
arm engages
smooth start.
RPM records
PROFESSIONAL STEREO -MONAURAL
AM -FM TUNER KIT
MODEL PT -1
$8995
The 10 -tube FM circuit features AFC (automatic
frequency control) as well as AGC. An accurate
tuning meter operates on both AM and FM while
a 3- position switch selects meter functions without
disturbing stereo or monaural listening. Individual flywheel tuning on both AM and FM. FM
sensitivity is three microvolts for 30 db of quieting.
The 3 -tube FM front end is prewired and pre aligned, and the entire AM circuit is on one printed
circuit board for ease of construction. Shpg. Wt.
20 lbs.
AUDIO
SEPTEMBER, 1959
"EXTRA PERFORMANCE" 55
WATT HI -FI AMPLIFIER KIT
A real work horse packed with top quality
features, this hi -fi amplifier represents a
remarkable value at less than a dollar per
watt. Full audio output at maximum
damping is a true 55 watts from 20 CPS
to 20 kc with less than 2% total harmonic
distortion throughout the entire range.
Featuring famous "bas -bal" circuit, push pull EL34 tubes and new modern styling.
Shpg. Wt. 28 lbs.
s
MODEL W7 -M
$5495
7
NOTE THESE OUTSTANDING SPECIFICATIONS: Power Output:
14 watts, Hi -Fi; 12 watts, Professional; 16 watts. Utility. Power Response:
I db from 20 cps to 20 kc at 14 watts output. Total Harmonic Distortion:
less than 2%, 30 cps to 15 kc at 14 watts output. lotrrmodulation Distortion: less than 1% at 16 watts output using 60 cps and 6 kc signal mixed 4:1
Hum and Noise: mag. phono input, 47 db below 14 watts: tuner and crystal
±
phono, 63 db below
14
14
watts.
HIGH FIDELITY AM TUNER KIT
MODEL BC -1A $2695
Designed especially for high fidelity applications
this AM tuner will give you reception close to
FM. A special detector is incorporated and the
IF circuits are "broadbanded" for low signal
distortion. Sensitivity and selectivity are excellent
and quiet performance is assured by a high
signal -to -noise ratio. All tunable components
are prealigned before shipment. Your "best buy"
in an AM tuner. Shpg. Wt. 9 lbs.
-WATT HI -FI ECONOMY AMPLIFIER KIT
MODEL EA -3
$2995
MODEL FM -4
New
From HEATHKIT audio labs comes an exciting new kit
Styling, New Features, Brilliant Performance! Designed to function
as the "heart" of your hi -fi system, the EA -3 combines the preamplifier and amplifier into one compact package. Providing a full
14 watts of high fidelity power, more than adequate for operating the
average system, the EA -3 provides all the controls necessary for
precise blending of musical reproduction to your individual taste.
Clearly marked controls give you finger-tip command of bass and
treble "boost" and "cut" action, switch selection of three separate
inputs, "on -off" and volume control. A hum balance control is also
provided. The convenient neon pilot light on the front panel shows
when instrument is on. Styled to blend harmoniously into any room
surroundings, the handsome cover is of black vinyl coated steel with
gold design and features the new "eyebrow" effect over the front panel
to match the other new Heathkit hi -fi instruments. The panel is satin
black with brush -gold trim strip, while the control knobs are black
with gold inserts. Shpg. Wt. 15 lbs.
.
"MASTER CONTROL" PREAMPLIFIER KIT
MODEL WA -P2
$1975
(Not Illustrated):
All the controls you need to master a complete high fidelity system
are incorporated in this versatile instrument. Features 5 switch selected inputs each with level control. Provides tape recorder and
cathode -follower outputs. Full frequency response is obtained within
± I/2. db from 15 to 35,000 CPS and will do full justice to the finest
available program sources. Equalization is provided for LP, RIAA,
AES, and early 78 records. Shpg. Wt. 7 lbs.
I
$9995
X77
$3495
HIGH FIDELITY FM TUNER KIT (FM -4)
The all new model FM -4 incorporates the latest
advancement in circuit design. Features include
better than 2.5 microvolt sensitivity for 20 db
of quieting, automatic frequency control (afc)
with defeat switch, flywheel tuning and prewired,
prealigned and pretested tuning unit. Prealigned
IF transformers and prewired tuning unit assure
easy -assembly with no further need of alignment
after unit is completed. The five tube circuit features a generous power supply utilizing
diode rectifier. Shpg. Wt. 8 lbs.
"UNIVERSAL"
12
a
silicon
WATT
HIGH FIDELITY AMPLIFIER KIT
MODEL UA -1
$2195
Ideal for stereo or monaural applications, this
12 -watt power package features less than 2r';
total harmonic distortion throughout the entire
audio range (30 to 15,000 CPS) at full 12 -watt
output. Use with preamplifier models WA -P2
or SP -1 & 2. Taps for 4, 8 and .16 ohm speakers.
Shpg. Wt. 13 lbs.
NEW!
MODEL TR -1A: Monophonic half -track record /p!avback with fast forward and rewind
functions. Shpg. Wt.
24
lbs.
MODEL TR -IAH: Half -track monophonic and stereo
record /playback with fast forward
and rewind functions.
$14995
Shpg. Wt. 35 lbs.
TRIAQ: Ouarter-track monophonic and
stereo with record /playback fast forward and rewind
MODEL
functions.
Shpg. Wt.
35
lbs.
$14995
NOW! TWO NEW STEREO -MONO TAPE
YOU'RE NEVER OUT OF DATE
RECORDERS IN THE TR -1A SERIES
WITH HEATHKITS
Offering complete versatility, the model TR-IA series tape recorders
enable you to plan your hi -fi system to include the functions you want.
Buy the new half-track (TR -IAH) or quarter -track (TR -1AQ) versions
which record and playback stereo and monophonic programming,
or the half-track monophonic record -playback version (TR -1A).
Precision parts hold flutter and wow to less than 0.35%. Four-pole,
fan cooled motor. One control lever selects all tape handling functions.
Each tape preamplifier features NARTB playback equalization, separate record and playback gain controls, cathode follower output,
mike or line input, and two circuit boards for easy construction and
high stability. Complete instructions guide assembly.
Heathkit hi -fi systems are designed for maximum flexibility. Simple conversion from basic to complex systems
or from monaural to stereo is easily accomplished by
adding to already existing units. Heathkit engineering
skill is your guarantee against obsolescence. Expand
and if you like,
your hi -fi as your budget permits
spread the payments over easy monthly installments
with the Heath Time Payment Plan.
...
AUDIO
8
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
CONTEMPORARY
Model CE -1B Birch
Model CE -1M Mahogany
CHAIRSIDE ENCLOSURE KIT
MODEL CE -1
No Woodworking Experience
Required For Construction.
All
Parts Precut
&
Predrilled
For Ease of Assembly.
TRADITIONAL
Maximum Overall Dimensions:
18"
Model CE -1T Mahogany
W.x24 "H.x35 % "D.
.
The modest cost of this basic speaker system makes it a spectacular buy for any
hi -fi enthusiast. Uses an 8° mid -range
woofer and a compression -type tweeter to
cover the frequency range of 50 to 12,000
CPS. Crossover circuit is built
in with balance control. Im-
Putting together !our own Heathkit can be one of the most
exciting hobbies you ever enjoyed. Simple step -by -step instructions and large pictorial diagrams show you where
every part goes. You can't possibly go wrong. No previous
electronic or kit building experience is required. You'll
learn a lot about your equipment as you build it, and, of
course, you will experience the pride and satisfaction of
having done it yourself.
$3995
MODEL SS -2
Legs: No.
DIAMOND STYLUS HI -FI
PICKUP CARTRIDGE
MODEL MF-I
91
-26 Shpg. Wt.
MODEL HH -1
and enjoy the fullest fidelity your library of
LP's has to offer. Designed to Heath specifications to offer you one of the finest cartridges
available today. Nominally flat response from
20 to 20,000 CPS. Shpg, Wt. I lb.
"RANGE EXTENDING" HI -FI
SPEAKER SYSTEM KIT
The SS -I
B employs a I5" woofer and super
tweeter to extend overall response of basic
SS -2 speaker from 35 to 16,000 CPS ±5 db.
Crossover circuit is built in. Impedance is 16
ohms, power rating 35 watts. Constructed of
3/4' veneer -surfaced plywood suitable for light
or dark finish. Shpg. Wt. 80 lbs.
$9995
SEND FOR FREE CATALOG
Describing over 100 easy -to -build
kits in hi -fl, test, marine and ham
radio fields. Also contains complete specifications and schematics.
AUDIO
lb. $4.95
26 lbs.
$29995
The startling realism of sound reproduction by the Legato is achieved
through the use of two 15" Altec
Lansing low frequency drivers and a
specially designed exponential horn
with high frequency driver. The special
crossover network is built in. Covers
25 to 20,000 CPS within ± 5 db. Power
rating 50 watts. Cabinet is constructed
of 3/" veneer -surfaced plywood in
either African mahogany or white
birch suitable for the finish of your
choice. All parts are precut and pre drilled for easy assembly. Shpg. Wt.
195 lbs.
HEATH
MODEL SS -1B
3
pedance is 16 ohms. Power rating 25 watts. Tweeter horn rotates so that the speaker may
be used in either an upright or
horizontal position. Cabinet is
made of veneer -surfaced furniture -grade plywood suitable
for light or dark finish. All wood
parts are precut and predrilled
for" easy assembly. Shpg, Wt.
LEGATO HI -FI SPEAKER SYSTEM KIT
$2696
Replace your present pickup with the MF -1
each
"BASIC RANGE" HI -FI SPEAKER SYSTEM KIT
IT'S EASY
. IT'S FUN
AND YOU SAVE UP TO
WITH DO -IT- YOURSELF HEATHKITS
.
$4395
Control your complete home hi -fi system right from
your easy chair with this handsome chairside enclosure in either traditional or contemporary models. It is designed to house the Heathkit AM and
FM tuners (BC -IA and FM -3A) and the WA -P2
preamplifier, along with the RP-3 or majority of
record changers which will fit in the space provided.
Well ventilated space is provided in the rear of t he
enclosure for any of the Heathkit amplifiers designed to operate with the WA -P2. The tilt -out
shelf can be installed on either right or left side as
desired during the construction, and the lift -top
lid in front can also be reversed. All parts are precut and predrilled for easy assembly. The contemporary cabinet is available in either mahogany
or birch, and the traditional cabinet is available in
mahogany suitable for the finish of your choice.
All hardware supplied. Shpg. Wt. 46 lbs.
pioneer in
"do- it- yourself'
COMPANY BENTON
C',
a subsidiary of Daystrom,
Enclosed find $
Please enclose postage
for parcel post- express
orders are shipped delivery charges collect.
All prices F.O.B. Benton
Harbor, Mich. A 20% deposit is required on all
C.O.D. orders. Prices
subject to change without notice.
ì
Inc.
C
electronics
HARBOR 25, MICH-
Please send the Free Heathkit
catalog,
name
address
city
&
state
QUANTITY
SEPTEMBER, 1959
ITEM
MODEL NO.
PRICE
9
www.americanradiohistory.com
AmericanRadioHistory.Com
LETTERS
Doppler Effect Dissension
FIRST
THEN
it was
exacting
military
industrial
applications ...
systems...
SIR:
...and
it's the
TV
MANUFACTURER
who sees the solution .
to his problem
The frame grid is the closest
approach to the ideal "Physicist's grid " electrical characteristics but no physical
dimensions. It results in: higher
-
FRAME
GRID
TUBES
FOR TV TUNER
6ES8
4ES8
6ER5
2ER5
AMPEREX FRAME GRID
The grid -to- cathode spacing toler.
ance is determined by the carefully
controlled diameter of grid support
rods (centerless ground) and by
61318
FOR MILITARY REQUIREMENTS
AND
EXACTING INDUSTRIAL APPLICATIONS:,
6688
6688A
6922
6922
5847
5842
CONVENTIONAL GRID
Grid -to- cathode spacing tolerance
depends on accuracy of grid dimension, obtained by stretching on a
mandrel, and on tolerances of holes
in top and bottom mica rod supports.
Diameter of grid wire must be large
enough to be self- supporting.
(MIL -E- 1/1216)
(MIL -E. 1/1166)
(MIL -E- 1/467)
(MIL -E -1 /466)
AVAILABLE FROM ALL
AMPEREX FRANCHISED DISTRIBUTOR
For additional data write to
Semiconductor and Special Tube Division
Amperex Electronic Corporation
230 Duffy Ave.,
Hicksville, Long Island, N. Y.
In Canada:
Rogers Electronic Tubes & Components,
116 Vanderhoof Avenue, Toronto 17, Ontario
.záir..:
\KtllIAU
ima,MILINIIIP111
...
LARRY S. ROGERS
1602 -5 ATW
transconductance per milliampere
tighter Gm and plate current tolerance low transit time low capacitances
lower microphonics
rugged construction
frame crossbraces between these
rods. Extremely fine grid wire eliminates the -island effect" usually
encountered in conventional tubes
with equally close grid -to-cathode
spacing. Rigid support of fine wires
reduces mechanical resonance and
microphonics in the grid.
With reference to Miss Rettinger's article "Loudspeaker distortion due to the
Doppler effect," we wish to disagree.
To quote the author, The Doppler effect
is characterized by a change in sound
pitch due to the relative motion of the
source and the observer." Using Fig. 1, a
16 -inch speaker at 22 cps with a cone
travel of 1 inch, we cante up with a forward piston velocity of slightly over 1
mile per hour. The Doppler effect at this
velocity can easily be checked by walking
toward a sound source at a speed of 1
m.p.h.
Miss Rettinger's method of checking her
results by an A-B test is, in our opinion,
worthless. The individual difference between speaker A (full-range single- speaker
system) and speaker B (three -way speaker
system) is by far more than the supposed
difference caused by the Doppler effect.
The only way actually to test the theory
Lv ear would be to feed a 40 -cps sine wave
and a 10,000 -kc sine wave into the same
speaker with a filter that could be switched
in to cut out the low frequency. We have
tried this and have found the difference
to be unnoticeable.
L. 1). DALESSANDRO and
ask Amperex
about applications assistance on frame
grid tubes for TV and FM tuners, and
on reliable premium quality (PQ) tubes
for industrial and military applications
APO 1 °_5,
New York, N. Y.
Stereo Miking
SIR:
This is in partial reply to a letter from
Mr. Morris in your August, 1959, issue. He
notes the lack of information on stereo
microphone placement or " miking." Miking
and mixing are, as he suggests, the secret
to all recording success. I agree with you
that $50.000 is very inexpensive indeed for
a manual on the topic.
Mr. Morris may find the literature on
monophonic talking useful. Over a number
of years, I have collected information on
titis field. Below are listed the books,
papers, and manuals I have found most
helpful.
1. Bernhart, Jose, Traité de Prise de Son,
Editions Eyrolles, Paris, 1949 (in French).
This is the only definitive work I know of.
Definite instructions are given for all sorts
of ntikiug situations. The point of view is
that being recognized by an increasing
number of audio engineers: the esthetic
experience that is music depends on creating within the listener a more or less well defined sequence of emotional states. Since
the psychological set of the listener at
hone differs from that in the concert hall,
there is no reason to suppose that physical
fidelity is necessary or even desirable. The
correct miking is that which delivers the
proper packaged emotion to the customer.
(Thanks to Ed Uecke of Capitol Records
for the last phrase.)
2. Berndt -Bach, Inc., Hollywood, Calif.,
How to Use Your Ciné- Voice, Oct. 1954.
This brochure is written from the point of
view of motion picture technique, and many
typical situations are illustrated.
(continued on page 98)
AUDIO
10
www.americanradiohistory.com
AmericanRadioHistory.Com
II,
SEPTEMBER, 1959
The First Book of its Kind
7>>
OF
'L
uafl
THE
BOOK
Nothing like SOUND in the THEATRE
has ever been published. It is the first
book to set forth in authoritative detail what
you can do with sound by electronic control,
and how to do it whenever the source (singer,
musician. speaker, etc.) and the audience are
present together. The book develops the requirements for electronic sound control from
the necessities of the performance, the characteristics of the audience (hearing and psychoacoustics), and the way sound is modified
by environment, hall, and scenery. Sound
sources are considered for their susceptibility
of control and need for it, and the many techniques for applying electronic sound control
are described and illustrated in thirty -two specific problems. From these problems are deAn
invaluable reference
- an
in-
dispensable guide for anyone
working in the theatre -a cam-,
plete technological thesaurus for
the engineer, architect, designer,
technician, student, and teacher
concerned with the reinforcement
\s,
of sound and speech.
TO BE PUBLISHED AT
$10.00
Prepublication price $7.75
i
}
!
3
The publishers of AUDIO invite you to purchase
the
It!
xtzrrs
tSTU
SOUND in
No Other Like
010
7.311.
-at a prepublication saving -the
THEATRE
completely new
by Harold Burris -Meyer and Vincent Mallory
rived systems and equipment specifications.
Complete procedures are given for: Planning,
assembling and testing sound control installations- Articulating sound control with other
elements of production- Rehearsals and performances Operation and maintenance of
sound control equipment.
-
THE AUTHORS
During the past thirty years, the authors have developed
the techniques of sound control in opera, open -air amphitheatres, theatres on Broadway, theatres on- the -road and
off-Broadway, in concert halls and night clubs, in Hollywood and in the laboratory. Some of their techniques are
used in broadcast and recording as well as in performances where an audience is present. From their laboratory
have come notably successful applications of sound control to psychological warfare and psychological screening.
HAROLD BURPIS -MEYER has written Scenery for the Theatre, the standard text on the subject, and Theatres and
Auditoriums, both done with Edward C. Cole. He also
wrote Acoustics for the Architect with Lewis S. Good friend. Presently an acoustical consultant to the Department of Defense, he is a fellow and past counsellor of
the Acoustical Society of America; fellow of the Audio
Engineering Society, Senior Member of the IRE, and member of the American Physical Society, The American Institute of Physics and the American Educational Theater
Association.
VINCENT
MALLORY is presently chief of the General
Equipment Branch of the Missile Guidance Division in
the Naval Ordnance. His background in acoustics dates
back to his days as an engineering student at the University of Pittsburgh, He first employed sound control in
the legitimate theatre in GRAND STREET FOLLIES of 1928
at the Booth Theatre. He has served as consultant in open air sound control for the New York City Department of
Parks. He has extensive experience in manufacturing having served as chief engineer with many fine companies.
He is a fellow of the Acoustical Society of America and
a member of the American Institute of Physics.
This prepublication scving certificate is worth $2.25
RADIO Magazines, Inc., Dept. 599
Post Office Box 629 Mineola, New York
I am enaosirg my remittance for $7.75, special prepublication price.
Send mj copy of SOUND in the THEATRE postpaid.
(No C.O.D., all books sent postpaid in U.S.A. and possessions,
Canada. and Mexico. Add LOc for Foreign orders.)
Name
Address
City
Zone
State
This offer expires October 15, 1959.
you make a blooper, you go back to practicing again, with more determination than
ever that the next time will be better,
nearer to perfection.
Not so with records. Mistakes can be corrected and so they are made. Music can be
re- performed, re-taped, patched together.
And right here, needless to say. is the musician's greatest beef about the art of re-
uDI0
cording-it deprives
cedward
1.
MUSICAL JAUNDICE
Following hard on the heels of last
month's installment, this postscript is being
written back home
am returned to audio land and the "normal" world (for me) of
records, hi fi, stereo and all the rest. It
was a good break, my expedition to the
Sewanee Summer Music Center in Tennessee; it gave me a big, new appreciation of
living music in the process of being put
together for live performance. I listened to
musical notes straight out of musical instruments-not out of loudspeakers, and I
(lid it day and night. I ate and drank live
music, slept with it, wallowed in it for a
whole mouth. And now I'ui musically vitamin-starved. Wouldn't have believed it.
There wasn't a quiet moment where I
was, practically ever, from the early -bird
tootlings of the first morning clarinet, up
betimes and against camp regulations to do
a bit of extra practicing, straight through
to the last cough of a wet French horn
blowing itself out for the brief night's rest.
(They are very wet instruments, especially
in a humid climate. Your pour then on the
floor, every few minutes.) There wasn't a
minute, all day long, when I could settle
down in my usual fashion, to contemplate
in respectful silence the greatness of the
audio art, or lose myself in the hi fi sounds
of Palestrina from the West Coast and
Gershwin from Vienna. Normally, I live the
world over, via records. Here in Tennessee,
the world shrank down to the size of one
college dormitory filled with practicing
musicians-and did they practice!
Bits and pieces of familiar music were
constantly drifting about my ears, or buzzing like annoying, persistent mosquitoes.
upstairs, a clarinet would start on a phrase
out of linihuis; down the corridor and in
another key a sour fiddle would scrape painfully out -of -tune scales, carefully, one note
at a tine. Next door, my bassoon friend
would blow a sudden explosion of grunts
and tvheezes, the of coon's way of warming
up, and start off on the bass part of something Icy Beethoven....
T know too 11111011 111:150 by now, alas. I
could always recognize these bits and fragments, or if I didn't. I'tl go crazy trying to
figure out (hero I'cl heard them before.
Meanwhile somebody else would plough into
next week's modern offering, perhaps a
piece like the "Kleine Kammermusik" of
Hindemith-teetittletee, tittle tee, tittle tee
tee -and play that one tiny little phrase of
music a hundred times, by count, without a
single perceptible pause. Tantalizing tunes
kept repeating themselves ad nauseuni, divided and subdivided into smaller bits for
concentration mi trills, jumps, and other
tricky passages, until I thought I'd go nuts
waiting for something new. It was like the
record that repeats grooves in the apartment upstairs, or the red traffic light that
won't turn green. Go on, play the nest ¡(art.
I'd tell silently to myself, tearing out hairs
* 78(1 Greenwich -t., New York 14, N. Y.
-I
ratnall Canby
in my anguish; but they never did; you
don't when you practice.
There were a few expert musicians
among these all -clay tootlers, mainly professionals on the faculty, who tossed off
their bits tvith life -like realism and polish
even if they never (lid get beyond a few
notes at a tine. I'd no sooner begin, thankfully, to enthuse over a really beautiful
phrase from, say, the Mozart Clarinet
Quintet, (down the hall) when the saine
phrase cvould float in again on the breeze;
half an hour later it would still be playing,
over and over. Then there was the Clarinet's
breath control practice, which consisted of
a single note begun extremely softly, growing to full volume and fading slowly away
to nothing. Eerie! It sounded exactly like
an electronic oscillator being turned up and
down.
Worst of all, there were the predictable
exercises, those dreadful, brassy, stupid
progressive tunes that all teachers write
for their special instruments, which start
on a pattern and keep it going for minutes
and minutes, moving laboriously upwards
or downwards. When one of these begins,
you feel you can't afford to take a breath
until the horrid thing reaches its lengthy
unwinding and stops. Truly hypnotic, like
the sight of a rattlesnake coiled and ready
to strike.
It was the beginners who really got me
down, though -the hard- working, admirable
students. I loved them, but not their instruments. When a student, off somewhei in
the very audible distance, started worm on
one of those familiar bits of melody, painfully dribbled out half-speed and out of
tune, I'd get ready to run for the nearest
woods. Wrong note. WRONG NOTE! No
-not that way! And as if responding telepathetieally to my agony, the distant instrument would stop, think things over
solemnly while I waited with baited breath,
then proceed to play the same passage and
the same wrong notes all over again. Oof!
I almost went out of my mind, trying not
to listen. Fin not much good at not listening.
There is, indeed, a hi fi moral to all of
this. We who listen to good records are
doubly spoiled with good music. True. the
live concert is the immediate end -product of
all the tortured practicing I heard -as the
resplendent new amplifier is the product of
the engineer's yearly sweating. The live
musical audience hears only the best
that the musicians can do and, like us. is
spared the hideous sounds of preparation.
But the record listener is even more a
victim of spoiling, for records are technically more perfect than concerts. .t fluff,
a wrong note, a minor slip-these are the
spice of the live concert and the human
evidence that music ix human and humanity
is frail, if endlessly determined. The very
fact that nothing whatever can be done
about it is a challenge of a special sort. You
play it right the first time-or else. And if
him of the challenge
of the perfect live performance, the musical hole -in -one. that is no longer necessary
and therefore in effect quite impossible!
No doubt about it, musicians do make
;tore mistakes in recording sessions than
they do in live performances. They can't
help it. But we, the spoiled listeners, never
even get to hear them. We are doubly removed from the reality of the musician's
experience. That's the way many nmsicians
feel, anyhow, and I think maybe they're
right.
Anyhow, I'm glad that I was able to
suffer for awhile in the birth -pangs of some
real, nascent music. It was worth it. I left
Sewanee like the proverbial shipwrecked
sailor, music, music everywhere and not a
note to drink; I was starved for good playing, for perfect playing. I had listened to
all the practicing I could possibly stand. I
craved, shall we say, the surcease of hi fi.
Just what the doctor ordered for my
species of chronic musical jaundice, with
more records coming in every month than I
ar. Maybe I ought to
can absorb in a year.
do this again.
2. MIRACLE SURFACE
Oh me. Oh nn-. Back about ten years ago
when the LP record first blossomed out in
plastic and the static problem raised its
ugly high- voltage snout for the first time
in earnest, I got excited about ways and
means to eliminate static. What really
worked nee into a tizzy was a blinding,
brilliant idea that struck me one day as I
was reading, I think, Popular .ci(((te
Monthly. It was so good that I wrote a
registered letter to myself, hired a Washington patent engineer -and got exactly
nowhere. Now I eau't even find the letter,
but no matter; RCA has come out with
- Miracle
Surface.
You see, I dabbled first with Static -Clean
and the like, the liquids which allow static
charges to leak away; I tried all the wet wash and detergent systems then being
promoted; I rushed out with a gleans ill my
eye to get an early model of the famous
Static Brush, with radioactive polonium
mounted in it -and I hit the national news fronts in those heady atomic days when I
suggested that the thing might be dangerous, perhaps. (It wasn't a bit; but then,
who amongst us knew much about radioactive elements then.) Come to think of it,
the gentleman of the press cvho picked me
up on the static brush was none other than
one John ('only, then a mainstay of Pathfinder magazine and since a hi fi and music
stalwart.
Anyhow, all of these proceedings seemed
to nie then-and seem to me now -quite
cart- before -the- horsish. It was obvious, to
me at least, that the right way to solve the
static problem was to pet hold of a record
(material that wouldnt develop static. So
simple in theory, but not so simple in the
patenting.
The Popular Science article wasn't about
records, of course. It merely described a
newly developed and astonishing fancily of
electrically conducting plastics. Don't remember the name, but I do recall that one
of them was spoken of as having a conductivity equal to that of mercury, which
still seems slightly unthinkable. But the
blinding light hit me instantly -why not
AUDIO
12
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
Stereo Preamplifier HF85
In
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and Mono Hi -Fi
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Ganged level controls, separate balance control,
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WORLD LAB -TESTED. Kit $69.95. Wired $109.95.
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Includes cover.
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HF86 28W Stereo Power Amplifier Kit $43.95.
Wired $74.95.
FM Tuner HFT90: Prewired, prealigned, temperature- compensated "front end" is drift -free. Pre wired exclusive precision eye- tronic" traveling
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In New York hear
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Cover $3.95. 'Less cover, F.E.T. Incl.
New AM Tuner HFT94. Matches HFT90. Selects
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Skc @ -3 db) or weak station narrow (20c
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Tuned
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New AF -4 Stereo Amplifier provides clean 4W
per channel or 8W total output. Inputs for
ceramic /crystal stereo pick -ups, AM -FM stereo,
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with a pair of HFS -5 Speaker Systems for good
quality, low -cost stereo. Kit $38.95. Wired $64.95.
HF12 Mono Integrated Amplifier provides complete "front -end" facilities and true high fidelity performance. Inputs for phono, tape head, TV,
tuner and crystal /ceramic cartridge. Preferred
variable crossover, feedback type tone control
circuit. Highly stable Williamson -type power
amplifier circuit. Power output:
25W
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Kit $34.95. Wired $57.95.
Includes
New HFS3 3 -Way Speaker System Semi-Kit com-
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Kit $39.95. Wired $69.95. Incl. Cover & F.E.T.
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HFS1 Bookshelf Speaker System complete with
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SEPTEMBER, 1959
13
almost nothing, relatively speaking -and in
general the necessity for a home -type, general- purpose component that has all the
out new material with the "conductivity of
mercury ". I thought to myself at mice that finesse of a highly professional machine yet
remains childproof, wife -proof, dog -proof
even a very slight electrical conductivity
and, (let's not forget) -changes records,
would suffice for our special purposes;
maybe this mercury material, in some form every time.
Skeptics have always been able to claim
or other, could be added to vinylite, in
that a changer is at lest a hideous comprosufficient quantity to reduce the static but
not enough to throw those delicately blal- mise, between lazy -man automation and the
true requirements of the "modern" record.
anced physical qualities of vinyl plastic
Ewen the very first changers, with their
a NVrV and gum up the presses.
(Ugh, said the careful amateur in pre, enormous bulk, their three-pound playing
they already add carbon black and that is heads and their lovely habit of smashing a
shellac disc every so often, were quite
a conductor; maybe my idea isn't so good.)
It wasn't anuateurishuess that stopped nie clearly as form of low -caste compromise.
The highbrow record collectors of the
cold, though, but simply the plain fact that
I could not get hold of the material itself, thirties didn't mind saying so, even then.
The high -type record collector disdained
nor offer any description of it to the govt.
I tried. My obliging lawyer looked up all the early changer, whether it was a Cape the patent literature and found nothing hart or a Garrard or what-have-you, and
that seemed to smack of my idea at fall. changed his 8's by hand, with his nose in
But, he said, I'd have to be specific about the air and as very satisfied look upon his
that conducting plastic. It, in itself, was big face.
No change -or not Bauch -as of today,
probably well protected; mine was merely
an idea for its use that hadn't been pro- in this basic attitude among the new hi -fi
faithful. ('hangers are still for the birds
pounded before.
i.e. the non -intellectuals, the non- dedicated,
Well, we tried liard, but those plastic
the background music listeners. the hazy
boys were clever. All I ever got was polite
letters suggesting that samples were not people, the button -pushers. The real gone
available and that further information hi-fi Haan changes his own, as always (handling the record ever-so- carefully by its
would he sent on at sin appropriate nuiedges, with a delicate swipe of a polishing
nnent; they'd put me on a list. I never heard
a thing again, as you may easily guess. cloth on the immaculate surface before he
Every attempt I made to get more infor- puts each one on the table) and most such
matiun led to the same block. So that was people are particularly proud of the fact
that their manual record playing equipment
that.
costs more than as comparable changer. It
Now roughly ten years later, RCA Lietor
must be good!
has announced "Miracle Surface." It is a
Well, of course, speaking generally, it
"new revolutionary anti -static ingredient
is. As I say, the changer people have been
one of the greatest technical ad317X"
on a mean spot, trying to keep up their
vances in recording of the decade (sic )."
mechanical prestige, so to speak. But as
Miracle Surface records will not attract
addust, will help to prevent surface noises almost always happens in such eases, out
versity-not severe enough to put them
and ensure faithful sound reproduction on
all RCA Victor Living Stereo records." of business, there being plenty of low -brow
Doesn't mention mono but we'll sup ose lazy people still around -has sharpened
their efforts towards improvement! Changthis to be a nacre oversight.
ers now try ever so manfully to be manual
"Miracle Surface records were developed
now a
after years of the most intensive and de- players too. Believe it or not, it isplayer!
tailed research by RCA Victor engin ors. virtue for a changer to he a manual
A true virtue, too. With the LP, manual
It has long been a dream of the record inmore
dustry to make record surfaces anti-sts tic. playing is honestly only a shade Autotroublesome than the automatic sort.
A large part of consumer complaints al out
matic playing still has annoyances that offrecords have always concerned the problem
of extra -musical noises and the accumula- set its values only too frequently, and no
tion of lint as the needle passes over the point in going into them-we all have exrecord grooves. Miracle Surface records perienced them.
The main value of a changer, today, is
eliminate these problems.'
Well, I say congrats to RCA and nay only in two mechanical operations neither of
which involves changing. The biggest usewonder -just having received the advance
fulness is the simplest, the automatic shutpress release--is whether the "compound"
de(the term RCA uses) is all the way through off at the end of a record. There, in onemost
vice, you have the most striking, the
the record or a natter of surface treatgenuinely practical aspect of the present ment, suggested by the trade name. No illumination whatever, at this point, but this day changer. When the record is done, the
is much too big a thing to keep excl'sive machine stops -there's none of that gentle,
persistent, gradually increasing rurrr, rurrr,
and, if it works as it should, we'll soon have
rurrr, rurrr, which indicates a record turnall the other companies' ideas on the Subalways haping idly in its final groove
ject- either with comparable materials,
licensed use of the same stuff, or with rau- pens when you are on the phone or in the
kitchen or outdoors or elsewhere; time and
cous objections.
just
If the new material does what it is sup- again you are likely to let the thing
run, quietly, for minutes, hours, even overposed to and keeps on doing it for the life
night. An automatic stop is the answer
of the record, if playing quality and reeod
and no two ways about it.
life are unchanged in the physical sense,
The other vital function, as I see it, is
then RCA has something tremendous here.
the automatic start. Now this, of course, is
Hey, RCA, how about tossing me a
not nearly as much of a straight conveniChristmas dividend? Like, say, a life membership in the RCA Victor Society of Great ence. It is usually much quicker and simpler
just to put your stylus in the groove by
Music. I could use a few more records.
hand and let -'er rip. But few of us can do
that little thing nowadays without at least
3. THE MANUAL CHANGER
one or two loud squawks of protest from
the speaker. Pickups are too light, our
The record changer makers have reaIly
hands too clumsy. The automatic start, inbeen on the spot these last couple of years,
volving the relatively slow process of put points
smaller
and
new
with
stereo,
what
(Continued on page 6?)
to
-down
force
lighter
stylus
our
styli,
on
use this type of plastic for record making?
Better -why bother to make a pure, all -
WAYS
To ENJOY
TNE
R,..oBER.TS
-
...
HOW TAPE
EQUIPMENT SERVES
MANY AUDIO NEEDS
22 are discussed in new
Roberts booklet
Roberts Electronics Inc. has prepared
this 20 page booklet to demonstrate
the wide versatility and high quality reproduction of monaural and stereo tape
equipment. Eight ways to record live or
from broadcasts and to dub or copy from
disks and tapes are discussed, including the
correct way to tape stereo broadcasts.
Also included
in
this informative booklet
are ten methods to play back through
high level and low level external amplifier /speakers in both monaural and stereo.
Suggestions are given for the use of tape
equipment to "dub in" vocal or instrumental accompaniment by mixing and multiple
recording.
The booklet treats with the general use and
care of tape equipment and instructions for
tape splicing, microphone placement and recording procedure. A complete index and bibliography are included.
Before you buy a tape recorder, you will want to
read this valuable booklet, "22 Ways to Enjoy the
Roberts." For your copy, just fill out and mail
the coupon below.
ROBERTS ELECTRONICS INC.
1045
N.
Sycamore. Los Angeles 38, Calif. Dept. D
a copy of "22 Ways to Enjoy the
Please send me
Roberts."
NAME
ADDRESS
CITY
ZONESTATE
Enclose 10c (stamps, cash) for handling & postage
-it
AUDIO
14
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
the all -new
VR -22
stereo
cartridge.
.5 mil diamond stylus. For professional -type tone arms, $27.95.
VR -225
.7 mil diamond stylus. For
record changer or turntable, $24.95.
VR -227
critical areas of stereo cartridge performance-- Compliance- Tracks
trace of stiffness. Channel Separation -Up to 30 db for maximum stereo effect.
Nothing higher on the market! Response- Smooth and flat for superior sound from 20 to 20,000
Now, outstanding in all four
precisely, not
a
cycles (VR -225), 20 to 17,000 cycles (VR -227). Virtually hum -free- triple shielded against stray
currents. This is our masterpiece. We urge you to hear it.
GENERAL
ELECTRIC
Audio Components Section, Auburn, N. Y.
AUDIO
SEPTEMBER, 1959
15
EDITOR'S REVIEW
TWO FOR THE SHOW
SEPTEMBER ROLLS AROUND and we begin to
enjoy a respite from the summer heat, we usually tell ourselves that now we can get down to
some serious work. Then we look at the schedule of
hi -fi shows and realize it was all a dream-even though
we do not attend all of them personally. Fact is, it
would be impossible to attend every one throughout
because they occur on the same days. One can't be in
Milwaukee and Houston on the same three days, nor
in Chicago and Dallas the following weekend.
The Chicago High Fidelity Show and Music Festival is always looked forward to as the beginning of
the fall buying season-the place where all the new
equipment will be shown to the public for the first
time. AUDIO readers already know what most of the
new gadgets are, since they have read the PRODUCT
PREVIEW in the August issue and, unless they read this
page first every month, they will have seen the continuation in this issue. But it is always more fun to
see and feel the new amplifiers, changers, turntables,
phono pickups, tape recorders, speakers, and so on,
than it is to read about them -although the reading
tells us the basic facts and sparks our interest in the
particular items we will look for. And listen to.
That brings up another question-how does one
judge an amplifier's quality unless he is familiar with
the speaker ? How do you judge a tuner unless you
know the quality of the station to which you are
listening and the quality of the particular record that
may be playing? To do a reliable job of judging anything, one must have some standard of reference. For
example, we like to carry a few records with us when
we are asked to evaluate a loudspeaker or a pickup or
even an amplifier-records with which we are thoroughly familiar. Even though it is generally recognized that most people do not have reliable aural
memories. the usual serious audiofan is actually an
experienced listener and if he uses the same records
all the time his comparisons are likely to be reasonably
reliable.
Fortunately, one or two records each year will become the "theme songs" of the hi-fi shows, and after
a few days we get to hear then so often that we can
arrive at an average of how they sound. Then we can
make valid comparisons. And we have also added a
new title or so to our own list of "familiar" records.
WLIEN
STANDARDS AND ADVERTISING
\Vii h the adoption by the Institute of High Fidelity
Manufacturers of standards for measurement of tuners and amplifiers, it should become much easier for
one to compare performance of these products by a
perusal of the specifications. The standards for measurements of tuners were published in these pages in
the May and June issues, and those for amplifiers will
be published 'n the October issue.
Since thes standards have been adopted by the Institute, we ..ssume that the published information
about members' products will be in accordance with
them, and we hope that each one will so indicate in
his printed brochures and advertisements. 11ná there
is no reason why the products of those manufacturers
who are not members should not also be measured and
described in the sane terms. Heretofore the information about products has not always been expressed in
the same ternis and it is something like comparing
automobile speeds measured over a course whose
length was established by surveyors using rubber
tapes.
We believe standards are essential whenever any
comparative''Idescription is presented. No AUDIO reader
is ever actually fooled by an advertisement which offers a "magnificent 30 -watt amplifier when the tube
list includes as power tubes a pair of 6V6's. Unfortunately, the general publie doesn't have sufficient
built -in protection to know the difference. On the other
hand, the philosophy behind the component manufacturers is such that they wouldn't attempt such a fancy
claim, and since their companies are generally comparatively small, it is probable that the chief engineer
sat in while the advertising was being written. In
many of the really big companies it appears that the
specifications originated on Madison Avenue.
MORE FM NETWORKING
The New York area, already well supplied Nvith good
Fl\1 programming, engenders a feeling of complacence
among those of us who like good music, and it is only
when we wander far afield -like across the Hudson
we run across a dearth of the kind of
River
music we prk fer. New York state is fairly well covered
-that
with music- largely from the QXR Network-and
there are a few such stations in New Jersey and
Philadelphia. With occasional exceptions, however,
when one gees south and west from Philadelphia the
aural fare begins to have a strong tinge of "country
music," and very few AM stations offer anything that
runs over tAiTo minutes, so they can accommodate more
commercial
The QXl Network carries the good music programs
of WQXR, New York-long the staple of many of the
metropolita i area's listeners. WHNC -FM in New
Haven join d the network in May of this year, and
more recently WTAG -FM of Worcester, Massachusetts, has entered the fold. The people of those areas
are fortunate.
.
AUDIO
16
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
an extra
measure of quality
-Tllfffl y
:111
1
111.
1 s1
.
111
INCHES
4
l
6
1
2
4--_5
3
10
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lil
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26
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29
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32
34
33
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36
38
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35
40
39
f111l1ll
Shown is PICKERING's Collectors Ensemble, Model 380E with
3
styli for stereo -microgroove -78's
The extra measure of quality in every
PICKERING product adds extra value...
extra convenience...to any high fidelity system!
The beautifully simple sculptured lines...the low,
sleek profile...the new look in quality stereophonic
pickups -this is the shape of good things to come -this is
the PICKERING Collectors' Series.
-
Without question, the 380 is the finest
with more features and more flexibility than any other
stereo pickup in the world. For example- the 380 is fully
encapsulated in precious mu -metal
for absolutely hum -free performance.
7
Only the Stanton Stereo FLUXVALVE features the safe,
comfortable, easily replaceable stylus assembly.
Visit your dealer for a demonstration today, you will
love the live, eager response to every nuance in
the record groove...you will find yourself
listening to a bright, delightful quality...second
only to the original live performance.
The only true way to judge a high fidelity component
is to compare it with another... measure
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all...the ear. Those who can hear the difference...
choose PICKERING
COLLECTORS' SERIES
Totally new and unique to high fidelity is the "Collectors' Ensemble "...a
complete quality "pickup- package" for reproduction of all records -stereo
-microgroove -78's.
Model 380E -Collectors' Ensemble, includes the Stanton Stereo FLUXVALVE
with 3 "V- GUARD" styli for stereo, microgroove and 78 rpm records $60.00
Model 380A- Includes Stanton Stereo FLUXVALVE with D3807A "V- GUARD"
stylus for transcription arms
$34.50
*PICKERING
- for more than
a
decade
-
the world's most experienced manufacturer
of high fidelity pickups ... supplier to the
recording industry.
FOR THOSE
WHO CAN HEAR THE DIFFERENCE
ickering
PICKERING & CO., INC., PLAINVIEW, NEW YORK
AUDIO
SEPTEMBER, 1959
Model 380C- Includes Stanton Stereo FLUXVALVE with D3807C "V- GUARD"
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$29.85
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0
17
Edwin Felch, project director in charge of developing the
Titan guidance system, holds the "voice" of the ICBM.
OF A GUIDED MISSILE
This is a missile -borne transmitter. It is the "voice"
part of a new radio -inertial
of a missile in flight
by Bell Telephone Labodeveloped
system
guidance
ratories for the Ballistic Missile Division of the
Air Force.
station monitors the progress of the flight continuously and obtains immediate evaluation of mission
success. And since the principal control equipment is
kept on the ground, expendable hardware in the
This versatile system helped deliver the nose cone
of a Thor-Able test missile precisely to its South
Atlantic target area -5000 miles from Cape Canaveral, Florida. So accurately was the nose cone placed
that a waiting group of ships and planes retrieved it
in a matter of hours. It was the first nose cone ever
to be recovered after so long a flight.
This radio -inertial guidance system is a product
of the Bell Laboratories- Western Electric development- production team. It is in production at Western
Electric for the first operational squadrons of the
...
The command guidance system which made such
accuracy possible combines precision tracking radar
with a special Remington Rand Univac computer.
Fed a steady stream of signals from the missile borne transmitter, the ground -based equipment compares the missile's flight path with the preselected
path. Corrective steering orders are computed and
transmitted automatically to the missile. The ground
missile itself is minimized.
Titan intercontinental ballistic missile.
Bell Labs scientists and engineers developed the
world's most versatile telephone network and much
of our nation's radar. They have constantly pioneered in missile systems. From their storehouse of
knowledge and experience comes this new achievement in missile guidance.
BELL TELEPHONE LABORATORIES
World center of communications research
and development
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Low -Noise AM Tuner Uses
Triode Input
CHARLES H. CHANDLER
and ALLEN R. GREENLEAF
With this simple conversion of the r.f. stage of
level
is
reduced enough to provide
rN
11 ;'rNEl? had it, origin
when one of the Writ VI',4 th(. 5etU1111
tuner ion put, but did not reduce
the hiss adequately until the upper audio
range had been cut down to :t frequency
response materially below that obtainable from ordinary table -top radios. This
was, of course, nnaceeptable. Finally the
tuner was sent to a laboratory for checkup and any necessary alignment, but the
laboratory teport!d that they were Tunable to improve it enough to meet the
owner's requirements for quietness.
By this time it was clear that the
problem was fundamental the available
signal was simply so weal: that noise
generated in the first tube of the tuner
overrode it. Since it was impossible to
obtain a stronger signal, the only way
Jut was to rechute the noise.
one) desired to receive A \I -N'AI
stereo broadcasts from \V(u1A1{, New
\ -mk. IIe was fared with a double problem
low signal strength because of
the shielding effect of the steel -frame
building iu Tvhich he lives, noel apparently sonie peculiarity of geographical
location: 2) interefereme iron] electric
devices within the building. As a first
step, he purchased an .A \l superheterodyne touer kit with 516(.1(11,11 loop, and
assembled it. The shielded loop greatly
reduced the inttrferenee, but the tower
produced a constant hiss tint made it
useless for enjoyable AAI reception.
Sever:11 persons who had experience in
the design and construction of radio receivers were eousulted, :und each manie
suggeslìous that were believed to ofi'er a
chance id. helping. In accord :lice with
sonne of these suggestions, the tuner's
rather cousideralble bandwidth was lia rowed, and several types of pentode r.f.
amplifier tubes, 811(1 several pentodes of
each type, were tried in till' t. nut 1,111
in the lope of finding one that was sufliieutly quiet. :1 \:fiable 10w -pass audio
filter that had been used successfully in
playing. worn 7S -rpor records was tried
*'
1
1
)
Marlborough At., Boston
16,
a simple superheterodyne AM receiver, the noise
good match for the FM tuner on stereophonic broadcasts.
at the
1
AN
:
a
:
Source of Noise
Now it is well known that triodes generate appreciably less noise than do pentodes, for reasons arising principally
from the greater simplicity of the triode
structure. For equally valid reasons,
however, triode r.f. amplifiers have not
been used in broadcast receivers since
some time in the 3)'s. No modern references could he found in the technical
literature to describe broadcast -hand ree1iver circuits \vith triodes. Older arrangements, using various complicated
Mass.
or critical neutralizing expedients. were
not considered suitable. It was therefore
necessary to design a triode front (01(1
according to modern concepts; this resulted in the circuit to be described.
Electronics engineer Chandler having
supplied a schematic of an AM tuner
with triode input, enough parts wore obtained for the ,lob, and the tuner was
built from scratch Hand debugged) by
duffer Greenleaf. As the product of a
ten- thuurb(r, the tuner is inelegant ill
appearance, but it is quiet in operation.
A toned- radio -frequency circuit was
first essayed, with encouraging. results.
However, there appeared to be no reason
why the triode could not he substituted,
with at least equal 5ueee55, for the pentode r.f. amplifier which, when used,
precedes the mixer stage of a superheterodyne circuit. Such It tuner was accord ingly construe ted on the salvaged chassis
of a Philco Alodel F -67S receiver, and
has proved extremely satisfactory. The
A7 -67S
was a complete a.c. %d.c.: battery
receiver, with an r.f. stage as the front
end. The 3 -gang tuning capacitor, ferrite -core antenna, oscillator coil, r.f.
transformer, and i.f. transformers were
retained for use in the new tamer; the
live 7- contact tulle sockets were rewired
for regular 6.3 -volt tubes.
\
B+
\
6_16
I
6AÚ6
\
IN34
L
00 55f
AND
a
AMP.
0
IE
I. F.
TRANSFORMER
TRANSFORMER
-<A
AUDIO
.07
b
R. F.
Fig. 1. Schematic
6C4
o o
MIXER OSC.
I. F.
55 V
100 NNF
Q-
AUDIO
OUTPUT
T
.LO.I
VC
diagram of tuner, showing novel r.f. amplifier stage.
SEPTEMBER, 1959
19
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AmericanRadioHistory.Com
Fig. 2. Photograph of tuner (front view).
Circuit Details
Let ms now consider the circuit design
details. In order to avoid stability problems. a .rounded -grid stage was used as
an r.f. amplifier. In this configuration,
the grid shields the input from the output, so that no neutralization is required
at the frequencies involved. However, a
cathode circuit, which is the input of a
grounded -grid amplifier, presents a very
low impedance to a signal source. This
would constitute a severe load on any
preceding tuned circuit unless a low impedance tap Nvere provided on the
antenna loop, as is done in transistor
radios. While an impedance match could
1w obtained in this way, the delivered
signal voltage would then be quite low
au intolerable situation in view of the
extremely weak signal available. An input cathode follower was therefore provided to drive the grounded -grid stage
directly. No a.v.e. voltage is applied to
this stage, since remote- cutoff triodes are
not available; however, this is not a
-
serious drawback because the tuner is
designed for weak -signal application.
As may he seen in Fig. 1, a 6J6 was
used for the combination cathode follower and r.f. amplifier. The second stage
is a perfectly orthodox 6BE6 converter,
followed by a similarly conventional i.f.
stage using a 6BA6; a.v.e. is applied to
both of these stages. The output is fed
to a high -quality diode detector of the
peak -to -peak type, a circuit that is gaining increasing favor in AM tuners because of its low distortion. Although the
audio voltage was low, its signal -to -noise
ratio was satisfactory. To bring volume
to a convenient level, a stage of audio
amplification was provided by a triode connected 6Aí'6, followed by a 6C4 as a
cathode follower. Two 6C4's, a 12AÚ7,
or a 6CG7 could, of course, have been
used for these functions. Decoupling
is entirely conventional; across -socket
shielding was found unnecessary. A separate power supply (with transformer)
is used; the highest voltage present (on
the plates of the 6J6, 6BE6, and 6C4
tubes) is 55, a figure suggesting "starved
amplifier" techniques. Higher voltage applied to the first stage increased hiss
somewhat.
The schematic shows the essentials,
and is believed to be self -explanatory. As
noted above, the r.f. and oscillator tuned
circuits were those that came with the
salvaged chassis, and operated satisfactorily. However, any standard make of
ferrite -core loop (the larger the better)
may he used as antenna coil; standard
replacement -type coils can likewise be
used for the r.f., i.f., and oscillator elements. Application of all tuned circuits
is precisely the same as in a superheterodyne of conventional design.
Standard alignment procedures were
used. After alignment, a linear dial scale
from one of the writers' archives was reproduced photographically to a size that
made exact scale readings occur at the
two tracking points. Although the scale
which was photographed had not been
designed for this tuner, the procedure
cited resulted in calibration more accurate than that of most commercial broadcast receivers. Figure 2, shows this dial
clearly on the complete tuner chassis.
The "front end" portion of the tuner
is shown in a below- chassis view in Fig.
3. The leads from the ferrite -core antenna enter at the upper left; the r.f.
coupling capacitor and grid return resistor are seen to converge at pin 5 of
the 6,16 near top center. The common
cathode resistor partially obscures the
6J6 socket.
The other tube socket at right center
is that of the converter stage. The cocoon like object just. below center is the oscillator coil, with the oscillator padder near
left center.
The 6J6 tube was a war surplus item
that was stated to be especially "quiet ized"- probably against microphonics
for the most part. (Actually, an ordinary
6J6 was equally satisfactory.) All resistors associated with the 6J6 stage were
of the deposited- carbon type. Unquestionably the principal factor in the improvement was the substitution of the
triode for the pentode, but low -noise
components were felt desirable in order
to preserve the full benefit.
Over-all performance of the novel AM
tuner is entirely satisfactory, and the
AM signal matches in quality the FM
signal from the same station as well as
AM and FM signals can be expected to
match.
Fig. 3. Portion of underside of tuner, showing
wiring of r.f. and mixer stages.
It is suggested that anyone who is now
afflicted with an AM tuner in which
front -end hiss precludes hi -fi results
might well see if it is of conventional
design, with a pentode as r.f. amplifier.
If so, it is almost certain that great improvement can be made simply substituting the triode front end of the tuner
shown in the accompanying diagram.
The same would he true of the AM section of an AM -FM "stereo" tuner.
.
AUDIO
20
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SEPTEMBER, 1959
All for Once, Once for All
EDWIN
F.
WIRSING`
When Forest Lawn Memorial -Park decided to present a special Good
Friday -Easter program, the audio men moved in and things began to pop.
is A 1115-foot vvide by .45 -foot
high oil rendering of the ('rucitixion or .lems Christ in a speciallybuilt flail, and forest Lawn \leowriall'ark, near Los . \ng(I(s, decided to
feature it in a special (food Friday pro gram with a sixty -pier( orchestra, forty pice chorus fund narration. Soue 121111
people attended by special incitation,
and portions of the proceedings Were
carried lice on radio.
The hallu'od halls began to rock
when first. the Columbia Broadcasting
System vvas convinced that the occasion
offered at splendid opportunity for using
its Los .Angeles ,A \l and l' \I facilities
to broadcast the program in stereo: second, it vras decided as an independent
operatinu to record the event in stereo.
tíot' SUGG-l), Pn.tivatlrng, ('oli f.
:iE:
AUDIO
And everything. was to happen at one
time, while
place.
n
lice
performance took
'fhe Glendale Symphony Orchestra,
comprised of hand -picked recording,
broadcasting, and motion picture musicians presented the music: another handpicked group of vocalists aweu,bled as
the Glendale Chorale: and Aeuerigo Marino, the Glendale Symphony's Colidnctor, wrote a special composition for
(hotus ami orchestra based on the massive crucifixion painting. by Jan Styka.
But the read drama cas in the prodigious task of getting a stereo broadcast
out of this lice performance with narration. Add to this the fact that stereo
recordings were to he ruade simultaneously, and one can understand why
fourteen microphones, thousands of feet
SEPTEMBER, 1959
of o:.I,Ie, mud carloads of technicians
sNA-ar and over the (went like it was ant
election -year Iwlitieal rouVention.
To say the least. a most cooporwiiye
1laestro .ilarino was confronted Acitlt
score than a conductor's share or problems. _Act-oreling to him, "We thought
had everything. under control, then
during drew rehearsal when the picture
was unveiled for purposes of timing,
the sound started hourxing off the huge
sholhteked canvas like rifle shots." The
imposing oil painting is n,rnuclly concealed behind a tremendous curtain, and
when drawn the acoustics of the roost
change completely.. So, it was during
this r(\-elation at dress rehearsal that
the audio engineers st-,pped everything
Ave
and indulged in microphone and level
adjusting.
21
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STAGE 220'
CHORUS
CHORUS
FM(I)
r
HORNS
WOODWINDS
07
SOLOIST
CONDUCTOR
D
MONO
rn
AM
FM
MONO
SEATS
SEATS
0
III
Fig.
1.
FOR STEREO BROADCAST (RCA 77D's)
...FOR
STEREO RECORDING
®
MONOPHONIC RECORDING
FOR
Alik
"SWEETENERS"
50'
-
TELEFUNKEN U47's
0
0
WESTERN ELECTRIC 639 CARDIODS
Diagram showing arrangement of orchestra and chorus, together with the microphone placement used for broadcast
and for stereo and mono recording.
The Problem
But let's start from the beginning and
reconstruct some of the challenges con fronting the sound crews:
The Hall of the Crucifixion at Forest
Lawn was built specifically to house the
painting; hence the unique dimensions
include about 220 feet of width, a hundred feet to the ceiling, and a scant 75
of depth. Adding to the problem, the
floor is scooped out like a shell with a
low point in the center. Approximately
12011 seats arch from side to side of the
hall in 12 rows. Only on one other occasion had there ever been live music
presented in the hall and that was during
dedication of the painting in 1951; and
at that time no attempt was made either
to broadcast or professionally record
the event. Consequently, there. was no
..past performance" to go by. So, it was
"once through for all and all for once."
When the CBS radio then first looked
at the physical facilities, they were for
being assigned elsewhere that night, but
up: The Hall of
one bright spot of
the Crucifixion has a very well situated
and vet secluded toaster control room
from which lighting, sound, and curtain
are manipulated. The room is located
opposite the stage about half -way up
and otters ample room for the necessary
personnel and audio equipment, which
included a portable isolation booth for
the "on- the -air" announcements which
the attending audience could not hear.
(The control room itself was too chaotic
with noise to take a chance without the
booth.)
Producer and director of the stere(i
broadcast, over K\X AM and F51 was
Sterling Tracy. Bob Chadwick, also of
the staff, rode the board as technical director. Both must be credited with a terrific job of organization and planning
which was reflected in the broadcast itself. No small part of the kudos must
he awarded the conductor, Amerigo
"Rickie" Marino. who is a proficient
radio and motion picture studio artist,
as well as a fine interpretive classteal
conductor. Rickie admittedly has worÌced
under a lot of tough acoustical conditions but. `never anything like this !"
It was obvious from the outset that the
orchestra had to be on risers w ich
would compensate for the dip in the enter of the auditorium floor. Hence, pecial platforms were constructed for the
orchestra and the chorus. Half of the
orchestra, and all of the chorus, was
above the conductor; as Marino stalted,
"I could hear reel well, but it was the
audience and the microphones we were
worried about."
We asked how critical the placement
of the sections of the orchestra was, to
which Marino replied, "It didn't make
any difference where we put the percussions, bass section, and horns, you could
hear thew rumble through the entire hall
during a triple pianissimo. We had to
umbrella the strings and woodwinds or
nothing would have carried but trumpets
on down."
What about the chorus?
"This, too, presented a problem,"
Marino continued. "They had to be close
to me because there was very little light
in the Hall, but the closer they were to
the orchestra the more difficult the separation because, no matter how many
mikes we used. The elevated position
helped since we had some of the mikes
'way up in the air, facing the chorus,
over the orchestra."
In other words, the entire standard
position and manner of performing had
to be altered from conventional concepts to compensate for the acoustics of
the hall.
Microphone Placement
Once the rehearsal got under way,
there were countless adjustments at the
request of the engineers, and had a less
skilled ensemble than the Glendale
Symphony been involved, the performance might have suffered due to lack of
rehearsal time specifically for the music.
Everything seemed to be dominated by
the high, long hall and the fourteen
AUDIO
22
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SEPTEMBER, 1959
teuapermeutal microphones.
In all fairness to ('BS, it might he
explained that only seven of the fourteen were used for the stereo broadcast;
four others were employed by Alilt
l'hilipsuu, audio engineer, who was producing' the stereo tapes of the event.
1'hilipsous problems were quite difforetit from those of the radio teen, as
will he noted from the diagram of mike
placement. Fill. 1. In making the tapes
the main concern \\:ts store() only and
cousertneuth, the inordinate way in
which the production was staged both
from the standpoint of the hall as (Yell
as the needs of the radio hoes, was nit
the hest for stereo recording. The radio
microphones had to achieve stereo with
AM and
in addition to furnishin
tick charnel with satisfactory sound to
couil,l with the F.C.C. requirements of
separate and iudepeuc1enl signals. The
radio microphones were never More than
eight feet apart at any position, while
l'hilipsun's mikes \veep set up to cover
inside as well as over -all sound.
There were three additional microphones used by Forest Latcn which 1(0(1
the performance recorded uonmphnnicatlly .just as at matter of history, but
they too, it might he added. had problems because the orchestras was split in
such an unusual \say that it required
delicate mixing. of three mike signals to
achieve a decent monophonic signal.
tbt top of this was the non -perfunctory
problem of having the narrator, Wendell
Noble, positioned Oil tilt' stage about
fifty feet away from the conductor, who
gave all the cues to the performers. .\
!I,
other problem was the "off- stage" announcer who fillet: -in l'or the radio audience; his portion was fed to radio but
eliminated from the tapes-another reason vvhy he had to he isolated.
Of the seven mikes used by Cuti,
two were used for AM an td two t'ur 1'' \i
the fifth and sixth were in a direct line
at center, one behind the conductor and
MIA' iu front ut' the chorus; these were
used to fill in to cash channel as needed.
The seventh radio microphone. was exclusively for the soprano soloist, Aliss
Alauie Gibson, and mixed to each char:
nel.
The actual program included the .following selections played for the halfhour preceding the broadcast: a Bach
tir from the SI/ ite .Vo. :, in I) ,211n jot..
The mammoth hall provided an impressive setting for the tumid of the music;
although the hall of the Crucifixion is
not a religious edifice, it creates that
feeling. _Next was Mozart's ',fiery 11S(1,
from the Requiem. The forty members
of the Glendale Chorale did most clearly
and definitely execute their part and the
over -all balance of chorus and orchestra
achieved by Marino was commendable.
F'intanden by Sibelius was next, and
it was no Mean task keeping the staccato trumpet passages from coutpletely
dominating the performance. 'l'he final
selection of the pre- hruadcast portitltt
included Jlaseagni's Iutcrnte _'u and tlu
Iniieggienro il Signor from ('nrullerio
1?rr.vtienrrn. Featured again was the
('horale with Miss (fibsctut, whose voice
carried extremely well in the resounding
chamber.
Than the broadcast, which was introduced with the typical tuning. up of the
orchestra. (in stereo), supposedly to
gi\e all the listeners at honte it chance
to make necessary adjustments. It (lid
seem et bit superfluous, however, since
the station had promotional spots running endlessly all day telling people to
get their sets placed correctly. The tuning' up bit took the edge off the opening
selection for the stereophonic effect.
First cruse the /fussiest/ Easter Orecttue by Iiiutsky- i'orsakotf. The stereo
ctl'ett. \cas tunst virile. I II'ill Not Leare
1-on. Comfortless., by Titeourb, was performed a cappella by the ('horale; and
in stereo it \cas fine; the ttco utike); ill
front of the group provided perfect
coverage.
Ituulel's i Ií nnae flrut .11!t Redeemer
Liretlr, featuring Miss (libsou. who now,
during the broadcast, was lea audible
tu the audience since the bouse I':\ system was leveled dozen to eliminate possible feedback during the broadcast.
Next the ]Inllelrrjnl, from 'The ,11e....inlr
and the churns seemed tu give it everyI
thing, leaving little, we fear, for the
Sunday Church services the individuals
might have been committed to for the
following Easter Sunday.
The climax of the program was the
presentation of the luge painting, with
the special music by .Alarino. Although
the original composition cas reminiscent
ut' sente vnotion pietmes, it did provide
compelling support and it was quite
apparent that the cutuposer studied the
acoustics before he started writing. The
(Cm/tin/red
ens
pnf)c 95)
Left, Bob Chadwick, radio technical director, Monophonic mixer in the center handled soloist
mike as well as two "cover"
mikes; AM and FM channels each used two mikes, eight feet apart. Right, Milt Philipson
at the control panel for stereo
recording, a part of Forest Lawn's facility; tape machines, microphones, and all radio equipment had
to be brought in. Philip son had to use 'phones because radio monitors to the left provided cues for other technicians.
Man at right, W. V. Stark of
Forest Lawn, was on phone to the auditorium with information about lighting effects.
AUDIO
SEPTEMBER, 1959
L?
Contributor y Infringement
of Patents
ALBERT WOODRUFF GRAY
An infringement can occur when information or material is provided with the intent that
it shall be used in such a manner as to negate the value of a patent to its owner. Thus if you
aid someone in infringing a patent, you may be just as guilty as if you infringed it yourself.
GIVING
.\ II)
OH
ASSISTANCE
111
the
infringement of a patent brings the
giver under the ban in the Biblical
Apocrypha, "Ile that touchetll pitch
shall be defiled therewith."
Vacuum tubes of a special type used
in patented radio receiving sets were
sold in the open market. Purchased by
the manufacturers of the supplemental
equipment for receivers, these tubes were
packaged for export by these manufacturers separately but in the cartons
containing the other equipment.
Owners of the combination patents of
these receiving sets protested to the
courts that the substitution of the tubes
contributed to the infringement of their
receiver patents. NO wrong was done,
said the court in that instance, until the
tubes were inserted in the sockets. The
patent )monopoly, it was asserted, dici
not (over the sale of the separate elements. however capable they alight he of
contributing to the patented invention.
waves and musical tone were
generated in a laboratory rather than
at a testing transmitting station.
"It is enough that it was necessary to
assetutile the tubes and the receiver and
to use theme as a combination of the patent in suit. The tests were made to see
if they were marketable- commercially,
and hence an infringing use. "2
decisions of the courts. With the enactment of the present patent law in 1952
this court -made law became a part of
that statute. By this present statute it
is now provided,
"Whoever actively induce, infringement of a patent shall be liable as an infringer. Whoever sells a component of a
patented machine, manufacture, combination, or composition, or a material or
apparatus for use in practicing a patented process, constituting a material
part of the invention. knowing the same
Phonograph Records
In its disimsition of this eontroveitsy
over the wrongful use of these vacutumn
especially made or especially
tubes the court but echoed the law as- to he
for use in the infringement of
serted long before by the United States adapted
and not a staple article or
such
patent,
Supreme Court. Under the Berliner patcommerce suitable for
of
commodity
ents for a "sound producing apparatus,
shall be liable as a
use,
noninfringing
phonographs and records were manu"'
infringer.
contributory
factured by the Victor Talking Machine
this
section of the
of
Characterization
Co. By another manufacturer at that
was in
Keport.
House
the
in
statute
time were made disc records adapted
incuntributory
of
doctrine
"The
part,
for use in the "sound producing appaof our law for
part
been
has
fringement
ratus" of the owner of these patents. Of
about 80 years. It has been applied to
the interference with combination patenjoin those who sought to cause inOnly when such association is made," ents that court said,
fringement by supplying someone else
concluded the court, "is there a direct
A combination is a composition of
infringement of the monopoly and not elements, some of which may be old and with the means and directions for ineven then if it is done outside the terri- others new, or all old, or all new. It is fringing a patent.
"One who makes a special device contory for which the monopoly is granted. however the combination that is the inThis is the basis for the doctrine of con - vention and is as much a unit in con- stituting the heart of a patented matributory infringement which permits templation of law as a single or noncom - chine and supplies it to others with directions, specific or implied, to complete
the elements or a patented combination posite instrument.
machine, is obviously appropriating
to be sold in this country with the intent
"Whoever uses it without permission the
that the purchaser shall make and use is an infringer of it. Whoever contrib- the benefit Of the patented invention.
It is for this reason that the doctrine of
the invention abroad.
utes to such use is an infringer of its It
"Hence, sales made in European coun- can slake no difference as to the in- contributory infringement, which pretries of goods unprotected in such coun- fringement or non -infringement of the vents appropriating another man's pattries by patent, were no infringement, combination that one of its element or ented invention has been characterized
as `an expression both of law and
irrespective of the patent protection all of its elements are unpatented.
morals.'
accorded in the United States."'
the
"For instance, in the case at bar
"Considerable doubt and confusion as
Later however, in this case, it 'was dis- issue would be exactly the same eve if
covered that these tubes, packed as they the record disc were a patented ar icle to the scope of contributory infringewere separate from the supplemental which this company had a right to use ment has resulted from a number of deequipment, had been inserted and tested or to which the owner of the patent ad cisions of the courts in recent years. The
purpose of this section is to codify in
in the factory before export.
no rights independent of his right to its
statutory form principles of contribu"The testing was a commercial use of use in the combination."'
and at the same time
patof
the
the complicated combination
For many years this law of contribu- tory infringement
ents, just as it is to be used by the ulti- tory infringement had been entirely)) the eliminate the doubt and confusion."
This statement of the purpose of the
mate purchasers, even though the re2 Radio Corporation of America v. Anpresent patent law provision, was sup* 11 ;? ?0 ; 'nd Drive, Forest Hills, N. Y.
drea, 90 Fed. 2d 612, dune 7, 1937.
(Continued on page 93)
3 Leeds & Catlin v. Victor Talking MaRadio Corporation of America v. Ans 35 1 .S.C.A., Sec. 271.
19,
1909.
April
325,
S.
213
U.
Co.,
1935.
chine
drea, 79 Feil. 2d1 626, November 12,
-
AUDIO
24
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AmericanRadioHistory.Com
SEPTEMBER, 1959
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magnet assembly that is 92% more efficient. In practical terms, the XP -1 combines in one compact
assembly the best features of high compliance with those of high efficiency. The magnetic lines of force
driving the woofer are totally captured in the air gap, where they belong, and where they can be put
to work toward unexcelled bass and transient response. Want proof? Hold a metal object near the
magnet of any conventional speaker; it will be drawn out of your hand. Then hold the same object near
the FISHER XP -1 magnet; nothing happens! Because there are no stray, wasted magnetic fields in the
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Export: Morhan Exporting Corp., 458 Broadway, New York 13, N. Y.
AUDIO
SEPTEMBER, 1959
CITY I, N. Y.
25
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AmericanRadioHistory.Com
What About Stereo
Multiplexing and Matrixing?
NORMAN H. CROWHURST
Here is a fair and impartial analysis of some of the methods proposed for stereo
broadcasting. The author describes each, and comes up with some conclusions as to
the probabilities of acceptance of any one of the systems within a reasonable time.
where
1)ossible separation between associated
"angels fear to tread ", but it
seems to ate as if some angels have
been stepping a little out of hounds. As
a man whose background is almost entirely in audio, I thought problems in
utatrixing and FM were best handled by
have encountered
the radio men. But
so many contradictions about the audio
end of this that I decided to take an interest. This is 'what I found.
channels 011 the saute FM carrier. service range, signal -to -noise ratio, and
possibly the ease in obtaining satisfactorily low distortion.
On the audio end is the question of
how stereo program is distributed between the two available channels allocated to it, the main modulation and one
suhcarrier. As far as the transmission
problems are concerned, there is no basic
connection.
The transmission channels do not care
whether they are transmitting left and
right, or L + R and L - R, or some other
combination. There may be some argument about whether full fidelity whatever that may mean) is required of the
suhcarrier channel, or whether a narrow
band will do, but there is no essential
connection with what the two channels
are used for.
So statements that "utatrixing robs
the main channel more than straight left
and right," or that one or the other way
of impressing the audio has inherently
higher noise level, are just bunk. WV-hat
does affect the system noise level. frequency range, distortion, and so on, is
M4YBE
THIS
IS
RI'SHING IN
I
The Problems
First the technical aspects need clarifying. There are really two separate
parts to the problem: the transmission
and the audio. From the transmission
viewpoint, the question is how we standardize subcarriers so we have two channels for stereo, and then, can we use one
or more additional subcarriers on the
sanie transmission for sottie other purpose?
Subearriers eau vary in allocation of
the total modulation "percentage" and in
location of the subearrier's frequency,
above the audio. All this is related to the
*?16-18 40th .trc., Bayside 61,
LEFT
L
AUDIO
R
MIXER
(MONO)
(L)
RIGHT
(R)
t".
.A'.
I
MATRIX
-R
SUBCARRIER
(STEREO)
MODULATOR
MAIN
MODULATOR 3
TRANSMITTER
TRANSMISSION
SUBCARRIER
TUNER
H
MAIN
AUDIO
L
+R
LEFT
RECEPTION
SUBCARRIER
FILTER & DEMOD.
L
Hg.
-R
1.
MATRIX
H
RIGHT
Basic arrangement of the Crosby system.
the distribution of available transmission energy, whichever way the audio
utilizes it.
Those are the only purely technical
considerations. Then there are some ecomaybe these should he
nomic ones
called political! At present FM- multiplexed subcarriers are being used for
background music private services. As
an economic fact, these services have enabled several FM stations to continue in
business. These are not likely to be prepared to relinquish this income, unless
stereo -or whatever else shows up-offers a more lucrative possibility.
Naturally, some high fidelity enthusiasts are appalled at the absorption of
sonic of the "high fidelity" FM medium
for such mundane (if not outrightly immoral) purposes. But we have to be
practical. People who run FM stations
must eat too. So there is an issue here
as to whether it is possible to have a
high- fidelity suhcarrier as well as full fidelity main carrier modulation and a
low -fidelity suhcarrier.
On this question one can get differing
answers ranging form some who do not.
believe even a single suhcarrier of any
kind can he used without "robbing" the
main channel in some way, to people who
affirm that as many as three or four sub carriers are quite possible, without any
diminution of quality.
As far as I have been able to ascertain, no figures exist on performance
with two subcarriers, although some experimental traumissions have been made,
and even tape recordings taken of them.
More than two subcarriers have vet to be
tried. The possibility is postulated solely
on figuring. Performance details with
only one suhcarrier are far from technically complete in most instances.
To complicate the "political" aspect,
arguments appear about what the second
subcarrier is to he used for, and about
the question of privacy or piracy. Multiplex Services assured me they are not
worried about the home user picking. up
a private service for non-commercial lis-
-or
AUDIO
26
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AmericanRadioHistory.Com
SEPTEMBER, 1959
AUDIO EMPIRE
ANNOUNCES
TWO NEW STEREOPHONIC
HIGH FIDELITY COMPONENTS
THE FIRST TO ACHIEVE
-
STEREO /BALANCE
MOST ESSENTIAL REQUIREMENT
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NEW
empire 98
STEREO/BALANCE TRANSCRIPTION ARM
Stereo /balance through dynamic balance-the outstanding achievement of the
new Empire 98 Transcription Arm. The geometry of the arm's design aligns the
center of mass at the pivot point, so that the arm is in balance in all planes. The
stylus exerts no greater pressure on either wall of the groove if the table is tilted
at any angle -even upside down.
Further, this balance is not disturbed with any required change in stylus pressure,
because changing stylus pressure with the Empire 98 does not shift the center
of mass as it does in arms where stylus pressure depends upon the position of
the counterweight.
The counterweight is only used to 'zero -out' the cartridge. Stylus pressure is
actually dialed with a calibrated knob. This knob adjusts the tension of a tern
perature compensated linear torsion spring which applies a torque force as close
to the theoretical center of mass as is mechanically possible. This knob is
calibrated in grams with an accuracy of 0.1 grams.
-
The natural resonance of the Empire 98 is below the threshold of audibility
(approximately 10 to 13 cycles). Precision ball- bearing races provide friction -free
compliance in both vertical and lateral movements. The cartridge shell accepts
all standard cartridges, is interchangeable, and is fitted with gold -plated, non oxidizing electrical contacts. Every detail of the Empire 98 substantiates the
careful planning that went into its design, and gives ample evidence of its
quality in action.
EMPIRE 98 12 " transcription arm $34.50; EMPIRE 98P 16" transcription arm
$38.50
NEW
empire 88
STEREO/BALANCE CARTRIDGE
The most impressive -the most dramatic feature of the new Empire 88 is
quality of its performance. It is difficult to equate and describe smoothness the
of
response, clean, articulate reproduction, dimensional fullness and balance -yet,
these are the sensations immediately evident with the first demonstration of this
remarkable cartridge.
The Empire 88 employs the much -acclaimed moving magnet principle, incorporated in a new, improved design. Frequency response extends from 20 to 20,000
cycles, ± 2 db. The outputs of the two channels are perfectly balanced within
± 1 db. Yet, interchannel isolation over the entire stereo frequency range is
better
than 20 db. Hum -free operation is assured by the use of modern precautionary
techniques: 4 -pole balanced 'hum -bucking' construction, mu -metal magnetic
shielding and 4- terminal output.
Aside from the noticeably superior performance of the Empire 88 over other
cartridges playing the same monophonic or stereo records, there is virtually no
groove wear. This is a result of the exclusive Empire 88 stylus lever design which
achieves high compliance (5 x 10-6 cm /dyne vertically and laterally) and dynamic
mass (less than 0.7 x 10-'- grams) diminishing to zero at high frequencies.
EMPIRE 88 with diamond stylus $24.50; EMPIRE 88S with sapphire stylus $18.50
See
and hear these quality stereophonic components at your high fidelity dealer today, or write for details:
Audio Empire -precision products of Dyna- Empire, Inc., 1075 Stewart Avenue, Garden City, N.
Dept. A -9
AUDIO
Y.
audi %mpire
in Canada: Active Radio & TV Ltd., Toronto 2, Ont.
SEPTEMBER, 1959
27
www.americanradiohistory.com
AmericanRadioHistory.Com
LEFT
MAIN
AUDIO
.T.
MODULATOR &
MIXER
TRANSMITTER
TUNER
--
SUBCARRIER
FILTER &
SUBCARRIER
RIGHT
-
MAIN
AUDIO
MODULATOR
LEFT
RIGHT
DEMO D.
RECEPTION
SUBCARRIER
TRANSMISSION
Fig. 2. Basic arrangement of the system according to the original Halstead
teeing in his own living room. Their objection is that availability of multiplex
adapters for ]Tome use means restaurants
can easily buy and use the same sets to
"steal" the program.
The answer to this is that you can also
buy devices for pickup of telephone conversations. but this does not imply legalizing. of wire tapping, infringement
of privacy, or an official "nod" to blackmail by means of it. Criminal infringement, using legally marketed equipment,
must still be clued for by proper police
action and legal process.
Apparently realizing this is a weak
ease, some are arguing that there are
more "legitimate" uses for subcarriers,
such as for expanding educational facilities. Now, we are all in favor of anything that will help out the appalling
shortage of classroom space and faculty
time in the nation's colleges and schools.
Probably nothing in this country is more
vital at this titue.
What surmises -and disgusts-me, is
to hear a proponent of one system accusing the proponent of another of
being opposed to such usage, when each
of the systems involved in the argument
is equally applicable
(or inapplicable)
to it.
In view of these attitudes, it takes
quite an effort with a mud-scraper to get
at the underlying facts. Let's take a
quick look at the current proposals in
the field.
The Crosby System
l'lii, :v,teDI
has been
explained ade-
AUDIO
MIXER
2L -R
ISOLATOR
L -R
DIFFERENCE
NETWORK
-L
RIGHT
(R)
AUDIO
ISOLATOR
MIXER
?Ft
-L
proposal
quately before. The essential feature of
the system is the use of matrixing in the
audio. The twain modulation carries left
plus right, the subcarrier left miráus
right. matrixing is necessary on reception to get true stereo, which means an
FM transmission using this system will
not be strictly compatible with existing
AM /FM transmissions. (Fig. 1)
The original Crosby recommendation
was for a subcarrier of 50 kc /s modulated between 25 and 75 kc/s (25 ke /s
deviation) and occupying half of the
available main carrier modulation,
which would he 37.5 kc /s. For the unmodulated subcarrier, this is a modulation index of 0.75, varying between 1.5
and 0.5 for the maximum swing of the
subcarrier frequency.
This can in turn he broken up into
sidebands of sidebands, most of which is
hypothesized on the basis of "100 per
cent" modulation over the range of amidio
frequencies, modulation index, or deviation ratio being referred to 100 per cent
modulation at the highest accepted audio
frequency. But if the modulation index
is 5 (the figure for "straight ", unnmlt.iplexcd FM) at 15,000 cps, 100 per cent
modulation at 1000 cps will represent a
modulation index of 15 times this, or 75.
This requires about 100 significant sidebands to transmit 100 per cent modulation at 1000 cps, extending about 100
kc /s on each side of the carrier.
But practical program modulation is
not as simple as this. One does not get
100 per cent modulation of any one frequency, but a peak excursion correspond-
i
MAIN
AUDIO
MODULATOR &
MIXER
TRANSMITTER
SUBCARRIER
MODULATOR
SUBCARRIER
Fig. 3. The revised Halstead arrangement represented in the Burden system.
28
www.americanradiohistory.com
AmericanRadioHistory.Com
ing to 100 per cent when the instantaneous peaks of the component audio happen to add up in one direction.
All this has to be done twice over in
multiplex: once in modulating the subcarrier, and again in applying the composite audio modulation to the main
carrier. Then it all has to he transferred
through the various stages from the
audio modulator to the antenna without
further distortion, which imposes more
rigorous requirements than previously
necessary for FM transmission.
Crosby reports his system capable of
quite low distortion figures, while others
reporting on WBAI (New York City)
experimental transmissions using the
Crosby system find much higher distortion figures. There is the reason for the
difference -system capability, rs. actual
equipment performance. And this is not
'unique to the Crosby system. It has to be
faced, in precisely similar fashion, by all
of them.
While the Crosby system is intentionally a wide deviation system, there
are no absolute figures in it. It is quite as
possible (or impossible) to put in another subcarrier, regardless of whether
or not sum-and-difference matrixing,
which is Crosby's basic feature and claim,
is used. Distortion, frequency response
and dynamic range on the subcarrier are
not affected by whether the signal it
carries is a null Fixed one or not.
The Halstead System
By this designation I refer to the
earlier proposal put forward by William
S. Halstead. This was to use "straight"
multiplexing without any matrixing:
left channel on the main modulation
with right on the subcarrier. To squeeze
in two subcarriers (in reasonable "comfort"), the proposal was to restrict the
right channel audio to a maximum frequency of 8000 cps, on the theory (which
was supposed to be hacked by experimental evidence) that frequencies above
this do not, contribute to stereo, so it's
enough if they come from the left only.
(Fig. 2).
The argument for the system was that
it did not interfere with the private
service operation and that it is compatible with the present AM /FM stereo, by
transmitting the right channel on both
the subcarrier and A11.
The argument against it was that it
is not compatible, in the sense that FM
receivers without adapters only receive
the left, rather than a mixed or monophonic program. Also very few high fidelity people will accept the hypothesis
about not needing anything above S000
cps on the right.
Everybody in the business has done
some changing of position, and now Halstead is going along with what we will
call, for the sake of distinction,
AUDIO
SEPTEMBER, 1959
NEW
TPA\ SDUCER.S
for infinite baffle installation
Introduction of the new JBL Linear- l:fliciencv
Loudspeakers has been met with overwhelming
demand. It is apparent that many audio
enthusiasts have been impatiently waiting
for a truly precision -made driver engineered
for sealed enclosure and wall installation.
The super 8" LE8 is a full range loudspeaker
which gives response from 30 to 15.000 c.p.s
that is smooth, clean, and accurate far beyond
that delivered by any other speaker of this
size ever made- Partly rev1nsihle is a silier
impedance compensating ring in the magnetic
circuit that controls power drawn by the
voice coil at high frequencies. 'File 1.E8 stakes
an ideal replacement speaker because
enclosure dimensions are not critical, and
acoustical requirements can be readily met.
An enclosed vohmic of only two cubic feet. or
store, is reconunendecl. The two-way
Linear - Efficiency SyJent kit. JBL \lodel
shown in the smaller illustrations, includes
JIiL Model LEH) Low Frequency Driver with
free air cone resonanceof 15 c.p.s.: JUL Model
1.X3 Dividing "Network for crossover at
1.000 c.p.s.: J IIL \lode) LE30 High Frequency
Driver, a completely new :5' z octave direct
radiator. This three units form an integrated.
perfectly matched, electro-acoustical system.
"'ley must be used together. All LE drivers
have a new type mounting flange that permits
mounting from the front, as well as the rear,
of the baffle. Handsome new enclosures for
LE units are the Dale, Madison, and \linigon.
Write for free technical bulletins describing
these extraordinary new transducers.
JAMES B. LANSING SOUND, INC.
3249 Casitas Ave.
Los Angeles 39, Calif.
AUDIO
SEPTEMBER, 1959
29
www.americanradiohistory.com
AmericanRadioHistory.Com
ated with the loudspeakers that emit
them first.
MAIN
AUDIO
MIXER
LORO
ISOLATOR
TIME
DELAY
1.9)
TIME
DELAY
AUDIO
MODULATOR &
MIXER
TRANSMITTER
1
RO
AUDIO
SUBCARRIER
MIXER
+LQ
ISOLATOR
MODULATOR
R
SUBCARRIER
the
Fig. 4. The Bell system, as it would be applied to "straight" multiplex; actually
experimental transmission used TV and AM -FM channels, separately, so it has not
been applied to multiplex as yet.
The Burden System
The Bell System
Developed by Richard W. Burden,
this originally aimed at overcoming the
objections tu the Halstead system. To
do this, it employs an alternative to matrixing. (hie might call it double matrix ing. To the left audio is added L -R, to
produce '1, -R for the main channel.
The saule component is subtracted from
or II- L added to) the right audio, to
produce ;21?- L for the subcarrier. ( Fig.
By this designation I refer to the system that has been demonstrated by
RCA/NBC with the Perry Conio show.
It uses a different means to achieve an
objective similar to that of the Burden
system, allowing both channels to carry
full program content, vet produce stereo
when both are used together.
It
(
:3)
This means both channels
I
with the in-
tent of covering the AM/FM situation)
carry left and right in different proportions and phase. When reproduced over
stereo speakers, the L-1? froid one
speaker is expected to cancel aeousticalh
with the R-1. from the other, leaving
just L and h' to be heard.
A further suggestion for the system
is to apply a further tnatrixing network
to the receiver adapter to retrieve the
true L and R electrically, which certainly ma kt,- better sense.
I
LEFT
AUDIO
(1)
MIXER
is not proposed for multiplex, but
since its compatibility problems are similar, but a method different from Burden's
is used to overcome them, it is iuclúded
here.
In this ease the Haas precedence effect
is used. The right audio is time delayed
by a fraction of a second, attenuated
slightly, and added to the left channel
and vice versa. Thus both channels earry
left. and right in equal strength, but with
time differences (Fig. 4). Because of
these time differences, which are not
enough to be noticeable on the individua
channels, the correct sounds are associ
MAIN
AUDIO
MODULATOR &
MIXER
TRANSMITTER
TRANSMISSION
RIGHT
(R1
1+0--
PHASE
INVERTER
LOW
PASS
SUBCARRIER
MODULATOR
-Rt
,UBCARRIER
The Calbest System
'l'he four systems so far described are
each basically different ways of handling
the audio fed into the transmitter. Originally Crosby favored a wide -hand sub carrier and Halstead a narrow-band one,
but these were not really esssential to
either's method. Actually, it would seem
logical that Halstead's original system
would benefit more from use of wide
band, while a ntatrixed arrangement
could better be adapted to a narrow
channel for the difference signal.
But the Calbest system is predicated
on use of a narrow band subcarrier.
They argue (again on the basis of
"tests ") that frequencies above 3500 cps
they proare not necessary to stereo. So
this
above
frequencies
all
pose to carry
on the Main modulation and to restrict
the subearrier to frequencies below this.
To achieve this without tuaking one of
the stereo channels highly deficient in reproduction, they reinsert the highs at
the receiver from the main channel. To
explain this let's designate frequencies
below- 3500 cps by the subscript nc and
those above by the subscript t. On the
main channel they transmit the complete
program 1,,n+ Rm + Lt + Rt. This is the
full mixed program, and in this respect
is the same as the Crosby. It is the sub carrier content that is different. On the
subearrier they put just R,,,. (Fig. 5)
The receiver juggles and rejuggles
this material so the left speaker presents
L»,+1/2(1., R,) while the right one
presents Rm +1/2(Lt +R,).
Disregarding, for the moment, the
questionable validity of the 3500 cps assumption, this system is compatible with
the present AM /FM transmissions, and
does do the other things claimed. The
question is whether Calbest's "findings"
about the need for stereo difference above
3500 cps are final. We do not dispute
their tests, but has everything been taken
into account? If we grant, for argument's sake, that present stereo does not
benefit from maintaining separate channels above 3500 cps, is it safe to presume
that improved techniques will not later
ey erse this derision? I believe they
probably will do so.
I
Reconciling Claims
T
ER
"LEFT"
MAIN AUDIO
+R,,, +Rt
Lm +Lt
RECEPTION
L,,,+Lt+R,
HIGH
SUBCARRIER
FILTER &
DE MO D.
PASS
PHASE
INVERTER
-Lt -Rt
"RIGHT"
_Rm Rt-L.
-Rm
on
Fig. 5. Basic arrangement of the Calbest system, which is the only one postulated
a
narrow band subcarrier.
There is no need to assume; as some
to, that one man tells the truth,
while his opponent must necessarily he
lying. The unfortunate facts are that so
little work has been done to coordinate
tests, and that there are so many variables in both multiplex and stereo.
Programs can be recorded by a wide
variety of microphone techniques. Many
of the tests claim to have tried a wide
(Continued nu page ti 1)
AUDIO
30
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
TO THE LATEST REPORTS ON PILOT STEREO!
We are not permitted to name names or quote quotes.
But a leading consumer
testing organization millions know and trust has given Pilot stereo
amplifiers and
pre -amps extremely gratifying ratings in a very recent report. While
you can't read
the report here, you can listen to it literally by simply visiting
your favorite
sound room and testing one or more of the Pilot stereo components
in question.
-
-
Pilot 210, Stereo Preamplifier.
Unique 3- position power switch
with optional automatic shutoff for equipment after last record
has played. Quadri- Volume control, permits synchronized
attenuation of both channels. DC filament supply for all tubes reduces hum
to an absolute minimum. Feedback tone control circuits for
low
distortion. 12 inputs, 6 per channel, for all associated equipment.
Two outputs -audio and tape. Low -impedance tape recording
output for long cables. Separate bass and treble controls. Response:
± 1 db, 20 to 20,000 cps. Harmonic Distortion: 0.2% at 1 volt output. Hum & Noise: 80 db below 1 volt. Obtains power from Pilot
260
Amplifier. 51/2" high x 145/8" wide x 11" deep. Wgt: 12 lbs.
Complete with enclosure. $89.50
Pilot 260, 80 Watt Stereo Amplifier.
IIIii1'ì'ì'î'ìì`I(IIIi(IIIIIII{III
I11{.
lil{IIIIIII
III11I I!{I llllil
IIIIIIIIIIIII
®
IIIIIIIIIIIIIJ1,11111111111IIIIIIIIIIII1I1
IIIIIIIIIIi.
!__
PILO
Founded 1919
AUDIO
Individual bias and
balance controls provided to adjust operating point and accurately
balance output tubes of each channel. Dual convenience outlets
to connect associated equipment. Power output -80 watts, 40
watts per channel, music power for 1% harmonic distortion.
70
watts, 35 watts per channel, music power, for 1/2% harmonic distortion. Frequency response: 20 to 20,000 cycles per second.
Sensitivity .8 volt for full power output. Hum level 90 db below full
power. Input impedance 470,000 ohms. Output impedance 8 or 16
ohms per channel. 9 tubes. 157/8" wide x 63/4" high x 73/4 deep. Wgt:
35 lbs. Complete with brass -finished protective cover. $139.50
TFor brochure describing Pilot's entire 40th Anniversary Series
of Stereophonic Components, write to Pilot Radio Corporation, 37 -04 36th St.,
Long Island City 1, N. Y.
SEPTEMBER, 1959
31
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AmericanRadioHistory.Com
Incorporating Tape into the
Audio System
HERMAN BURSTEIN'
Practical hints on the methods of installing a tape recording machine into a typical home system that may assist the tape user in deriving the greatest satisfaction
from it. Making the connections at the right places can easily save countless headaches in the use of a recorder and is more likely to improve the results obtained.
-
signal sources
phono, radio, and T V -the tape
machine is generally employed not
only to feed signals to the audio system
but also to receive signals from the system for the purpose of recording them.
Both in playback and recording there
are various ways Of connecting the tape
machine to the rest of the system, and
one must take into account the relative
advantages and disadvantages of these
alternatives.
UNLIECE THE OTHER
Recording from the Audio System
Seldom is the tape machine connected
directly to the signal source-such as,
for example the tuner -when recording
from a high fidelity system. In order to
be able to record readily from the tuner,
TV, or phono -without changing cable
connections-the tape machine is ordi*2SI) Twin Lave E., Wantagh, N. F.
INPUT
JACKS
LEVEL SETS
AMPLIFICATION
o
STAGE
O
o
O
o
signals
Fig. 2. Method employed in some control amplifiers for feeding incoming
recorder.
to a tape
narily fed from a point following the
selector switch of the amplifier, as was
shown last month in Figs. 15 and 1¢, reproduced here as Figs. 1 and 2. In the
ease of the magnetic phono cartridge, it
is usually impossible to connect directly
to the signal source because very few
tape recorders contain the equalisation
and amplification facilities necessary for
TO A TAPE RECORDER)
MAGNETIC
PHONO
INPUT
JACKS
Fig.
1.
1
O
--40
FOLLOWING STAGES OF
THE CONTROL AMPLIFIER
O
O--
SWITCH
PREAMP
O
AUX O
JACK
SELECTOR
LEVEL SET
TAPE OUTPUT JACK
O(FOR FEEDING SIGNALS
TAPEO
TAPE
OUTPUT
FOLLOWING STAGES OF
THE CONTROL AMPLIFIER
i
TUNER O
TVO
-O
SIGNAL SOURCE
SELECTOR SWITCH
PREAMP
Method employed in some control amplifiers for feeding incoming signals directly to a tape recorder.
directly accounnodating a magnetic pickup. On the other hand, it may be feasible
to feed the signal from a piezoelectric
or capacitive cartridge directly into a
tape recorder.
For simplicity, connection is frequently made at the output of the power
amplifier, that is, to the speaker leads,
as shown in Fig. 3. Alligator clips offer
a ready means of making this connection; the clips, which are soldered to a
shielded cable, are fastened to the bared
speaker leads; the other end of the
shielded cable goes to a phone jack that
feeds the signal to the tape recorder's
high level input jack. One can purchase
a ready -made cable with the alligator
clips and phone jack soldered in place.
Connection to the speaker leads is
most frequently employed with a commercial radio or radio- phonograph console that does not provide a tape output
AUDIO
32
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
AMP FA
STEREOPHONIC
960
RECORDER/ REPRODUCER
ABOVE --960 PORTABLE STEREO
RECORDER/REPRODUCER
Stereo
Portable
BELOW --MODEL 2560 PORTABLE
STEREO SYSTEM CONSISTING OF
960 AND PAIR OF 2010
AMPLIFIEî- SPEAKERS
PLUS!
-
Guiding the Ampex engineers who created the 960 was a dual objective
that of building a machine which was not only a superb example of
engineering skill, but one which would also offer its user
a range of capabilities far exceeding that of any other recorder made today.
The result was not merely an improved stereo recorder,
but an entirely new concept in home entertainment.
The STEREO 960 fits into family life in literally dozens of ways, contributing many
tangible benefits in musical, educational and recreational fun. You'll use it to keep up the
family correspondence by sending "letters in sound ", to tape stereo programs off the air,
to preserve your best monaural and stereo discs on tape, and to acquire new musical and language skills.
You'll have endless fun exploring the 960's many fascinating recording capabilities, including
sound -on- sound, echo chamber effects, and other advanced techniques.
SIGNATURE
OF
www.americanradiohistory.com
AmericanRadioHistory.Com
PERFECTION
IN
SOUND
Relax and enjoy the show
let your Ampex do the
narration! With the
commentary on tope, your
color slide shows ore more
RECORDER /REPRODUCER
SPECIFICATIONS
professional, more complete
and more fun!
The true values of
a recorder are best assessed through careful evaluation of its performance specifications and operating features. It is worthwhile noting here that these specifications are based not on
theoretical design parameters but on actual performance tests. They are specifications which the
recorder not only meets or exceeds today, but which years from now will still hold true.
The Ampex Model 960 Stereophonic Recorder, Reproducer is capable of essentially distortionless
frequency response from 30 to 20,000 cycles per second at the operating speed of 71/2 inches per
second, and from 30 to 15,000 cycles per second at 33/4 inches per second. Its precision -engineered
timing accuracy is such that it offers perfection of pitch held to tolerances of less than one -third of a
half -tone. Playing times, using standard (.002 "), long play (.0015 "), and extra -long play (.001 ") tapes
are as
Stereo Tapes
ips - 2 hrs. 8 min.
71/2 ips
hr 4 min.
33/4 ips - 3 hrs. 12 min.
71/2 ips hr 36 min.
33/4 ips - 4 hrs. 16 min.
71/2 ips - 2 hrs. 8 min.
foot reel
33/4
800
foot reel
:400
foot reel
RECORD INPUTS: High impedance line inputs
(c)
1
1
1
1
When you tape it "off the
air" your only cost is for
blank tape. Yet your musica
repertoire can soon equal
that of all the stations
you hear!
Monaural Tapes,
half -track
33/4 ips - 2 hrs. 8 min.
71/2 ips hr 4 min.
33/4 ips - 3 hrs. 12 min
71/2 ips hr 36 min.
33/4 ips - 4 hrs. 16 min
71/2 ips - 2 hrs. 8 min.
(b) 2 -Track
Stereo Tapes
hr. 4 min.
33/4 ips 71/2 ips - 32 minutes
33/4 ips hr. 36 min.
71/2 ips - 48 minutes
33/4 ips - 2 hrs. 8 min.
71/2 ips hr. 4 min.
1
1
Your favorite LP's and Stereo
Discs are at their exciting
best while they're new and
unscratched. That's when to
tape them on your Ampex,
and preserve their original
quality for keeps!
follows:
(a) 4 -Track
200
-
1
1
(radio TV: phono auxiliary) 0.3V
rms
a real future in family
fun like this-with your
Ampex you can live such
happy moments over and
over again, with a quality so
lifelike you're almost literally
carried back.
There's
for program level;
high impedance microphone inputs
PLAYBACK OUTPUTS: Approximately 0.5V rms from cathode follower when playing program level tapes
PLAYBACK FREQUENCY RESPONSE: 30- 20,000 cps at 71/2 ips; 30- 15,000 cps at 33
71/2 ips, 55 db dynamic range
33/4 ips, 50 db dynamic range
ips
Within ±2 db 50- 15,000 cps at
Within ±2 db 50- 10,000 cps at
FLUTTER AND WOW: Under 0.2% rms at 71/2 ips;
under 0.25% rms at
33/4 ips
In the Ampex "Speech Testi
HEADS: Manufactured to the same standards of precision that exist in Ampex broadcast and recording
studio equipment. Surfaces are lapped to an optical flatness so precise that they reflect specified
Game ", you pit your wits
against the trigger -quick
memory of the Ampex
recorder /reproducer. You
can't win, but it's fun trying
wavelengths of light, resulting in uniform performance characteristics and greatly minimizing the
effects of head wear. Azimuth alignment of stereo head gaps in the same stack is held within 20
seconds of arc, equivalent to less than 10 millionths of an inch
a degree of
precision achieved
through use of a unique process involving micro- accurate optical measurements within a controlled
environment. Head gap width is 90 millionths of an inch +5 millionths of an inch.
-
Letter -writing is no longer a
problem, with an Ampex
in the house
now it's a
family project. And even
more fun than sending letters
in sound is receiving them!
...
KEY TO THE EXCITING FUN
FEATURES OF THE 960
--
THE AMPEX STEREO -GRAPH
Here's the simplest, quickest answer
to almost every question about how to
perform the operations illustrated at
right and numerous other recording
functions. The Ampex Stereo -Graph
shows you, quickly and clearly, the
proper dial settings to make for more
than a dozen of the most popular uses
for the 960 .. including sound -onsound, language and music instruction,
For "letters in sound
3" tape reel holds
letter, mails
first class anywhere in the
United States for 8c.
as a 10 -page
and other special effects. A convenient
tape footage /playing time indicator is
included on the reverse side.
.
MODEL 2010
MATCHING
", the
as much
The Ampex, in private
rehearsal, can be a wonder
AMPLIFIER -SPEAKER
confidence.builder for
people who normally devel
rubber knees when faced
with the prospect of
speaking before a group.
The Ampex Model 2010's ten-watt (20 watts peak) ampli-
fier section provides operating characteristics (unequalized)
flat within =-0.1 db, with total harmonic distortion less
than 0.5 of %, throughout the maximum range of human
hearing ability, at rated output. Noise and hum are 80 db
below rated output, and input sensitivity is 0.18V to
1
Learning to speak a new
language is made
immeasureably easier on
the Ampex; you can record
your own phrases side-by -side
with those of the instructor,
and play them back for
comparison at any time.
develop rated power.
The specially designed 8" speaker provides smooth, peak free response throughout a remarkably wide audio range.
Such superior design features as its massive die -cast frame
and edgewise -wound ribbon coil contribute effectively to
higher levels of performance than ever before achieved
with a speaker this size.
MODEL 960 DIMENSIONS: Portable cases
9"
13" x 15" x 61/e" depth below top plate,
speaker amplifier 31 lbs.
AMPEX
AUDIO.
INC.
x
1311"
15" x 171/2'. Unmounted recorder
above. Recorder weight 36 lbs.,
SUNNYVALE.
CALIFORNIA
AANS
When you strike up the ban
in stereo, you don't need
professional musicians to
make a professional
recording. Advanced
techniques are amazingly
easy on the Ampex.
PHONE
PLUG
HIGH LEVEL
INPUT JACK
SHIELDED
CABLE
SPEAKER
ALLIGATOR
CLIPS
LEADS TO POWER
TRANSFORMER
Fig. 3. A means of feeding an audio sig-
nal to the tape recorder.
jack (for feeding a tape recorder). This
is the easiest course for the neophyte
because it does not require him to go
"inside" the set. But there are several
disadvantages. The most serious, perhaps, is that the signal is picked up after
the volume control of the set. If one has
correctly adjusted the gain control of
the tape recorder for proper recording
level-high enough for adequate signal to -noise ratio, low enough for imperceptible distortion-the adjustment is
upset when one varies the setting of the
volume control of the commercial set.
If, for example, one turns down the
volume when answering the telephone,
one has also reduced the recording level.
Another disadvantage -how serious
depends upon the quality of the commercial set -is that the signal is apt to
be of lower quality after the output
transformer of the power amplifier section than at earlier stages. If the output
transformer is of the $2 or $3 variety so
commonly found even in fairly high priced commercial consoles, the signal
here is apt to contain significantly more
distortion and significantly worse frequency response, particularly at the bass
end, than at other points in the amplifier.
Accordingly, it is preferable to pick
up the signal at a voltage- amplifying
stage, which requires going inside the
unit. However, the connections are fairly
simple. The easiest thing, ordinarily, is
to connect a shielded cable across the
unit's volume control, as shown in Fig.
4. Note that the connection is to the high
( "hot ") and low (ground) terminals of
the control and not to the arm. Hence
the signal fed to the tape recorder is independent of the volume control setting
of the commercial set.
Connecting to the volume control
raises a problem which generally does
not occur when connecting to the speaker
leads, namely serious attenuation of
treble response. The cable, depending
upon its length, may add as much as
AUDIO
SEPTEMBER, 1959
several hundred micromicrofarads of capacitance to the circuit of the commercial
unit, which may be enough to cause a
substantial loss of high frequencies. A
partial or complete solution is to use a
minimum length of cable from the set
to the tape recorder, under three feet if
possible; and to use cable having low
capacitance per foot (about 25 µµf per
foot is readily obtainable).
As a further expedient, if necessary,
it may be feasible to make a simple
change in the amplifier stage prior to
the volume control that will reduce the
effect of cable capacitance. This presumes that the stage in question is simply
a voltage amplifier and has no bass,
treble, or other forms of tone control
associated with it. The procedure, illustrated in Fig. 5, consists merely of
connecting a feedback resistor from the
plate to the grid of the tube. Feedback
reduces the output impedance of the
tube and makes the frequency response
at its output less subject to the effects
of capacitance (of the cable) added to
the circuit. On the other hand, the gain
of the tube is also reduced, but usually
there is gain to spare. The value of the
PHONE
PLUG
/
VOLUME CONTROL
OF SOURCE
INNER LEAD
(HOT)
SHIELDED
SHIELD
LEAD
í,,
Fig. 4. Another means of feeding the
audio signal to the tape recorder.
feedback resistor should be experimentally determined; it will probably lie between about 220k ohms and 1 megohm.
Recording from a High Fidelity System
Virtually all modern high fidelity control amplifiers or integrated amplifiers
provide a tape- output jack for feeding
the audio signal to a tape recorder. However, the circuit location of the tape -output jack varies from one amplifier to
another. The circuit location may be perfectly satisfactory in certain instances
and less satisfactory in others.
As illustrated in Fig. 1, a number of
control amplifiers feed the incoming signal directly to the tape recorder; that is,
the signal goes immediately to the selector switch, and the arm of the switch
goes to the tape- output jack. This
method has one possible drawback,
namely that the capacitance of the cable
leading to the tape recorder will attenuate the treble response of the signal
source, namely the radio tuner or the TV.
Nowadays most radio tuners have a low impedance output (ordinarily a cathode
follower), so that a good many feet of
cable can be employed without significantly affecting treble response. Some of
the older tuners, however, have an output direct from the detector, and here
the cable is apt to produce significant
high- frequency loss. Moreover, few if
any TV sets have a low output impedance, so that the cable is likely in this
instance to take a toll of treble response.
On the other hand, in many TV sets, in
order to compensate for inadequate high frequency response of their inexpensive
speakers or for other reasons, the treble
de-emphasis network is less than the required 75 microseconds; that is, high frequency response is excessive at stages
prior to the speaker. Hence the effect of
the cable leading to the tape recorder
may well be to bring frequency response
closer to correct balance rather than to
unduly subdue the high end.
Should the cable produce undesired
treble loss when the signal source is an
FM tuner or TV set, the de- emphasis
network can be modified to compensate,
as illustrated in Fig. 6. It is assumed
here that the de-emphasis network consists of a 1000 -µµf capacitor and 75kohm resistor, and that the cable to the
tape recorder adds 200 µµf of capacitance. The 200 µµf of cable capacitance
is in effect in parallel with the 1000 -µµf
capacitor, making a total of 1200 µµf. In
order for the time constant of the network to remain at 75 microseconds, the
resistor should be 62.5k ohms. The nearest standard value, 62k ohms, will suffice.
The problem of cable capacitance are
usually avoided when the tape- output
jack is located as in Fig. 2. Here the
jack conies after a low- impedance stage
(usually a cathode follower), which permits a long run of cable without adverse
effect upon high -frequency response.
However, on occasion one will find an
amplifier, usually an older unit, where
the stage preceding the tape -output jack
is of medium or high impedance. In this
ease one must be careful of cable length.
FEEDBACK RESISTOR ADDED TO CIRCUIT
(220 K OHMS TO MEGOHM)
1
SHIELDED CABLE
TO TAPE RECORDER
ire
VOLUME
CONTROL
Fig. 5. Reducing the effect of cable ca-
pacitance upon high frequency response
by adding a feedback resistor.
35
CHANGE THIS RESISTOR TO 62 K OHMS TO
COMPENSATE FOR ADDED CAPACITANCE
OF 200 NNf.
DETECTOR
ADDED CAPACITANCE DUE TO
CABLE FROM CONTROL AMPLIFIER
75 K
TO TAPE RECORDER
OUTPUT JACK
200 NNf
1000 PPf
NETWORK
WITH 75psec TIME CONSTANT
TREBLE DEEMPHASIS
(CONNECTED TO CONTROL
INPUT JACK AND TAPE OUTPUT JACK
Fig. 6. Changing the deemphasis network in a FM tuner to compensate for capacitance added by a cable.
As suggested in the preceding section,
one might make this stage more tolerant
of cable length by inserting a feedback
resistor of about 221)k ohms to 1 megohm
between the plate and grid; this involves
some loss of gain, which generally can
be accepted. In fact, in certain instances
the loss of gain may be beneficial be-
grated amplifiers, the tape -output jack is
located prior to the tone controls and
other frequency- shaping circuits such
as the loudness control, rumble filter,
scratch filter, and presence control. The
logic is that one will thereby obtain a
"flat" recording. To illustrate, assume
one is making a tape recording while
TAPE
AMPLIFIER
OTHER CIRCUITS
(OSCILLATOR, ETC.)
INPUT
OUTPUT
AMPLIFIER
Fig.
CABLE FOR TAPE
7.
How
feedback
RECORDING
CABLE FOR TAPE
a
loop
may occur.
PLAYBACK
CONTROL
INPUTS
JAC K
O
O
AMPLIFIER
TAPE OUTPUT
/i'
AMPLIFIER OR
CATHODE
FOLLOWER
AMPLIFIERS,
TONE CONTROLS,
OUTPUT
ETC.
O
SELECTOR
SWITCH
cause it reduces the danger of overloading the stage in question and running
into noticeable distortion.
of Tape- Output
Respect to Tone Controls
Location
Jack
with
listening to the audio system at very low
level (perhaps late at night). Then the
loudness control or bass control or both
will usually be set to produce a good deal
of bass boost, compensating for the
seeming drop -out of bass at low liOytening levels. For the same reason, the treble
1-
In most control amplifiers or inte-
GANGED
TAPE AMPLIFIER
INPUT
INPUTS
/
--6
/
-7
O< /O
/
O TAPE OUTPUT
JACK
OoTP_T
O
O
SELECTOR
SWITCH
Fig. 8. Method employed in some control amplifiers to prevent feedback loop.
may also be accentuated. However, one
does not ordinarily wish this bass and
treble boost to reach the tape, for they
will cause unnatural accentuation at
medium and high levels of reproduction.
Moreover, the augmented bass and treble
may produce serious distortion on the
tape. By having the tape- output jack
precede the tone -shaping circuits, one
obtains an electrically flat tape recording.
On the other hand, there is good reason why one might wish to have the tape
output jack come after the tone -shaping
circuits so that the frequency response
of the signal can be altered before it
reaches the tape. It is well known that
disc recording companies often add a
great deal of treble boost to the recorded
material in order to impart an artificial
brilliance. When recording a tape at
speeds of 7.5 ips or less. a very large
amount of treble boost is incorporated in
the tape amplifier in order to preserve
high- frequency response; this boost
brings one close to the point at which
the tape is overloaded. If the material
being recorded on tape comes from a disc
that unduly emphasizes the highs, overloading is quite likely to take place.
Therefore it would be very desirable to
cut the treble before the program material reaches the tape. Not only is overloading avoided, but the tonal balance of
the tape recording is now more nearly
flat to the ear. Flat acoustic response is
obviously more important than flat electrical response, namely mere preservation of the signal frequencies in their
original relative amplitudes without regard to balance.
AM reception offers another example
of why it might he desirable to shape the
frequency response of the signal before
putting it on tape. Typically, AM reception is deficient in the high end (more
often the fault of the tuner than of the
broadcast station). A certain amount of
treble boost will often improve matters,
particularly if the signal is a strong one
so that treble boost does not bring up
static and sounds from interfering stations to an appreciable degree. If the
treble- augmented signal is put on tape,
then the tape bears a closer approach to
flat acoustic response than the signal
originally delivered by the AM tuner.
In the above case it may be countered
that one could just as well supply the
treble boost when playing back the tape
rather than in recording. This is true,
but the results would be less satisfactory.
The more signal one can record on the
tape -within the limits set by the susceptibility of the tape to overloading
the higher will be the signal -to -noise
ratio in playback. Application of treble
boost prior to recording augments the
signal on the tape. On the other hand,
use of treble boost in playback brings up
the noise on the tape (hiss and modulation noise) and the noise of the tape-
-
AUDIO
36
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
orchestra
pit
in
beersheba
When the Martha Graham dance group toured Israel, six AR -2 loudspeakers, with
tape reproducing
equipment, were taken along to provide musical accompaniment under circumstances where it was
impractical to use live musicians.
Above are four AR -2's mounted in the orchestra pit of Cinema Karen in Beersheba (two more were
placed
backstage). These speakers were selected for the job because of their musical quality; the natural
sound
of the live instruments, rather than pseudo -hi -fi exaggerations, was desired.
AR acoustic suspension speaker systems -the AR -1, AR -2, and AR -3 -are designed primarily for
use in the
home, but are also employed extensively by professional laboratories and studios. They are priced from
$89 to $231.
Literature
is
available on request.
ACOUSTIC RESEARCH, INC.
AUDIO
SEPTEMBER, 1959
24 Thorndike Street
Cambridge 41, Mass.
37
TAPE OUTPUT JACK
(FOR RECORDING)
TAPE INPUT JACK
(FOR PLAYBACK)
INPUTS
(EXCEPT TAPE)
o
OUTPUT
MONITOR
TAPE
o
o
TAPE- MONITOR
SWITCH
from a tuner or TV set. If one is using
a two -head machine, there is the possibility of a feedback loop, as illustrated
in Fig. 7, which can produce a formidable howl or squeal due to oscillation. This
can occur if the tape machine is in the
record mode and at the same time one
happens to set the selector switch of the
control amplifier to admit the signal
from the recorder. What might happen,
depending upon the tape machine, is as
follows
In some tape recorders the output
cable always remains connected to the
tape amplifier circuit, whether the machine is in the record or playback mode.
This amplifier circuit, it will be remembered from earlier discussion, is used
:
GAIN CONTROL
a
Fig. 9. Tape- monitor switch arrangement for accepting the playback signal from
tape m achine.
place the tape- output jack at an early
stage, prior to the tone controls, a substantial number of stereo amplifiers
place the jack at a late stage. This has
certain advantages in addition to enabling one to control the frequency response of what goes on the tape. Loc tion
at a late stage usually means that o e is
recording what one hears. To illustrate,
if the left and right signals are combined (as when playing a mono disc with
a stereo cartridge), then the combined
sponse.
All told, an optimum combination of signals are recorded on the tape. If the
high signal -to -noise ratio and low dis- balance control has been brought into
tortion is achieved by making the neces- play in order to correct for differences in
sary tonal corrections, if any, before the level between the channels on a stereo
tape is recorded rather than in play- disc, then the signals recorded on the
back. Accordingly, placement of the tape have also been brought into balance.
tape- output jack after the tone -shaping If only channel A is being played, then
circuits can be a valuable feature. Of only channel A is recorded on the tape.
course this means that when recording a And so forth.
tape one has to consider what goes on Playback into the Audio System
the tape rather than the prevailing reIn many control amplifiers or intequirements for pleasant listening. To illustrate, if the audio system is operating grated amplifiers, the only means for acat low level and one is making a tape at cepting the playback signal from a tape
the same time, one may have to forego machine is through a high -level input
jack-usually marked TAPE AMPLIFIER or
loudness compensation.
AUXILIARY -which puts the tape signa
in
monoWhereas the usual practice
phonic control amplifiers has been to through the same route as the signa
playback amplifier, thereby deteriorating
the signal -to -noise ratio.
It should further be noted that the
program material may contain too much
or too little bass. Too much bass may
overload the tape; bass may be in the
form of audio signals or rumble frequencies. If there is too little bass, one
endangers the signal-to -noise ratio by
waiting for playback to introduce the
bass boost required for flat acoustic re-
NORMALLY CLOSED JACK
(OPEN WHEN PLUG IS
IN TAPE INPUT JACK)
Fig. 10. Another tape monitoring arrangement.
both in record and playback, except for
changes in the equalization employed.
Accordingly a signal enters the input
jack of the tape machine, is amplified
by the tape amplifier, is fed by the output cable to the input of the control
amplifier, goes to the tape -output jack
of the control amplifier, again enters the
input jack of the tape recorder, is further amplified, etc. This is an oscillatory
process that produces the howl or squeal
referred to.
To avoid this possibility, a number of
tape recorders disconnect the output
cable from the circuit when they are in
the record mode. For the same reason, a
few control amplifiers have adopted the
expedient of Fig. 8. The tape- output
jack of the control amplifier is disconnected from the circuit when the selector
switch is turned to the tape amplifier
position.
Another and more popular expedient
employed in control amplifiers is that of
Fig. 9. Here the tape -input jack is connected to the circuit by a special switch
at a point following the tape-output
jack. The arrangement of Fig. 9 is commonly referred to as a tape- monitor
switch. Its primary purpose is in connection with tape recorders having separate record and playback heads. It permits one to switch quickly between the
incoming signal that is being recorded
and the playback signal off the tape, so
that one may immediately check whether
the tape recording is a reasonable facsimile of the original signal. At the same
time, the tape- monitor switch serves the
purpose of breaking up a feedback loop
that might otherwise occur.
Figure 10 illustrates a different monitoring arrangement intended for use
with tape recorders having separate record and playback heads. When the plug
of the playback cable from the tape machine is inserted into the tape input
jack of the control amplifier, it breaks
the path of other signals entering the
control amplifier. In order to hear the
original signal, say from a tuner, one
must depend upon an "A -B" switch
(Continued on page 64)
AUDIO
38
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
THE NEW
THAT
The
RECORDS!
Push-Button
Miracle
for stereophonic and
monophonic
high fidelity sound !
1VII RAC ORID
XS 200
The pushbutton miracle of high fidelity sound -with every practical and proven
feature for the perfect reproduction of stereophonic or monophonic records.
it's a heavyweight, professional -type
turntable -and a fully- automatic
Magic Wand spindles eliminate pusher
platforms and stabilizing arms!
intermixes 10" and 12" in any sequence;
plays all 4 speeds, has a 4 -pole motor.
Plug -in head!
shuts off automatically, returns tone
arm to rest position!
and many other outstanding features,
not found in any other record changer
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changer!
a special switch adapts Miracor(l to
stereophonic or monophonic reproductin, with finest quality output on
either system!
vibration eliminated by special mounts!
5 push -buttons permit you to start,
stop, pause, repeat or filter, without
touching tune arm!
-yet
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it costs onig $
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STE
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thrilling new standard
stereo
a
cartridge!
in a
Acclaimed by engineers and audiophiles, STEREOTWIN 210 /D is the finest
cartridge for the stereo age. "Moving- magnet" principle gives new high
in quality performance. Hum is eliminated by Mu -Metal casing.
Stylus replacement is instant. Phenomenal separation: 22 db at 1000 cps.
EXCLUSIVE ADJUSTMENT puts stylus in proper position both vertically and
horizontally for record changers or manual tone arms.
Truly an audio engineer's cartridge at an audiophile's price!
NOW $
345°
FAR AHEAD) THE FINEST BY FAR
Available at selected dealers.
For ET,' catalog ac, please Irrite Dept. il
AUDIOGERSH CORP.
514 Broadway, New York 12, N.
AUDIO
SEPTEMBER, 1959
Y.
WORTH
6-0800
39
A Ten -Watt All- Triode Amplifier
ROBERT M. VOSS
and ROBERT ELLIS
Build this simple low- powered amplifier using a pair of relatively new dual- triodes in the output stage and see how good
a small amplifier can sound -with efficient speaker systems
.
Iu the early days of electronics the only
type of tube used for amplification
was the triode. The reason for this
was simple; the tetrode and pentode had
not yet been developed. With the discovery that higher gain could be achieved by
the use of a screen grid, designers
jumped on the bandwagon, and the tetrode and later the pentode were thought
to render the single -grid tube obsolete.
When the emphasis on faithful sound
reproduction came into vogue, audio designers were forced to do some further
investigation, for listening tests (as well
as refined electronic measurements) revealed some facts which had not previously been noticcd. For unkown reasons
(some of them still uncertain) some
triode amplifiers with low power ratings
sounded cleaner than equivalent pentode
circuits with more than double the triode
audio output.
As high- fidelity grew up, audio fans
became convinced of the superiority of
* 697 West End Ave., New York 25,
N. Y.
Fig.
1.
one or the other class of tube, and circuits were developed which proved the
virtues of either triodes or tetrodes. The
Williamson amplifier, which probably
gave high- fidelity its biggest boost,
showed that a well- designed low -power
triode amplifier could reproduce cleaner
sound than any of the high -power circuits used at that time.
Triode advocates, however, had a short
lived victory, for, in 1953, David Hafier
and Herbert I. Keroes showed that an
Ultra-Linear connection of the output
tubes would more than double the undistorted power output of the triode
Williamson. This revived popularity in
the Williamson circuit, as well as giving
a great deal of publicity to the (then
young) third school of output -stage
thinking. Partly as a result of the publicity given to the ultra -linear Williamson, this type of connection is now very
popular with amplifier designers.
However occasional circuits are still
developed which are particularly suited
to triode output tubes. This amplifier is
External appearance of the authors' amplifier. Follow this layout for simplest
wiring.
one of them. 6BXTs are relatively unknown to audiofans; as far as we know
no commercially built amplifier and only
one published circuit uses them. In Radio-Electronics, February 1957, Norman
V. Becker described an amplifier which
delivered eight watts at less than 1/2 per
cent total harmonic distortion from two
6BX7's and a $2.95 output transformer.
Although Mr. Becker pointed out the
great potentialities of the 6BX7 as an
audio tube, it has not received the attention it merits.
One of the most notable virtues of the
amplifier described here is its efficiency.
Remember the power supply of the Williamson.? It delivered 450 volts at 120
ma to the output stage. This is more
than 50 watts, but the audio output was
only rated at 12 watts. Our amplifier,
Fig. 1, delivers 10 watts with a d.c. input of 25 watts ; it is almost twice as
efficient An additional feature of the
output stage, which uses two 6BX7's in
push -pull (actually, four 1/26BX7's in
push -pull parallel is more accurate) is
its low driving requirement ; the grids
require only half the signal that the
Williamson output stage did.
The early stages of the circuit, Fig. 2,
bear a close resemblance to the corresponding part of the dullard 520 amplifier. The change here is the use of a
triode voltage amplifier instead of the
original pentode. A triode furnishes
enough gain so that, with 20 db of feedback, the amplifier requires only 0.5
volt for full output. We did not use an
input level control because such controls
frequently become noisy even if they are
never touched after being initially set.
If you want to decrease the sensitivity
of the amplifier make up a voltage divider to fit your needs, making sure that
the total grid resistance seen by the
6AV6 does not exceed 0.5 megohm.
The plate of the voltage amplifier is
connected directly to the first grid of
the cathode -coupled phase splitter, thus
providing the necessary d.e. potential for
the grid. We chose this type of phase
splitter mainly because of the fact that
the output impedances from its two sides
are equal, therefore eliminating problems
of unequal high-frequency phase shift
that we have encountered with the other!
AUDIO
40
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
O
D
ALTEC LITTLE -GIANT BOOKCASE SPEAKER SYSTEMS.. .low as
Highest efficiency of any comparable system tested -21/2 to 31/2 watts nominal for
average room listening -peak ratings as high as 20 watts Test against any other
speaker system selling for up to $50-more for frequency response
presence
efficiency
Price them. You'll buy ALTEC for the highest sound value.
-
ALTEC 834A
MONTEREY
ALTEC 835A
MONTEREY JR.
This is the ultimate
in compact speaker
systems. The Mon-
Quality of reproduction equals or exceeds
systems costing up
to twice as much.
Finished on all four
-
ALTEC 700B MELODIST
sides for use in horizontal or vertical posi-
The most performance in the smallest
package. ALTEC's Melodist is made to
order for small apartments, or as a second speaker in stereo sound systems.
tions. Employs ALTEC's famous con-
Contains ALTEC's engineered bass
trolled- linear- excursion bass speaker that
always repeats exactly what it hears.
Direct -radiating cone tweeter.
speaker, plus the same high- frequency
speaker used in more expensive ALTEC
systems.
Specifications:
Guaranteed frequency range: 20- 18,000
cps.
power rating: 15 watts
impedance: 16 ohms
finish: walnut, blond,
mahogany
dimensions: 111/4" H, 23"
W, 111/4" D
approximate shipping
weight: 45 lbs
price: $79.50
Specifications:
Guaranteed frequency range: 70- 22,000
cps
power rating: 20 watts
impedance: 8 ohms finish: blond, mahogany
dimensions: H101/8"
24 lbs
111/4 ", W- 2334", Dapproximate shipping weight:
price: $126.00
terey uses
two
controlled - linear-excursion bass speakers, and ALTEC's
3000B high- frequency sectoral horn. At
40 cycles this outstanding system has,
for the same power input, more than
five times the audio output of any other
small speaker system tested.
Specifications:
Guaranteed frequency range: 40- 22,000
cps
power rating: 20 watts
impedance: 8 ohms
finish: walnut, blond,
mahogany
dimensions: 14" H, 26" W,
141/2" D approximate shipping weight:
45 lbs
price: $174.00
COMPLETE ALTEC SYSTEMS FOR MONO OR STEREO
For a monophonic system use ALTEC's 355A amplifier -preamplifier with
ALTEC's 306A AM -FM or 307 FM tuner, and any one of ALTEC's compact
speaker systems. Now, or in the future, you can have an ALTEC stereo
system by simply adding another 355A, a matching speaker system, and
ALTEC 355A 20 -WATT
AMPLIFIER -PREAMPLIFIER
ALTEC S40 MASTER
STEREO CONTROL
$12.00
the inexpensive 840 master stereo control.
ALTEC's advanced engineering and manufacturing methods guarantee
big- speaker sound in small packages. That's why any one of ALTEC's
three compact systems is an excellent choice as a second speaker if you
want to convert your present mono system to stereo.
355A Specifications: frequency range: 20- 22,000 cycles power output:
20 watts load impedance: 4, 8, and 16 ohms seven separate inputs
tape recorder output
four position loudness control
three position
scratch filter three position rumble filter dynamically balanced output
four separate volume controls separate power switch separate bass
and treble controls four position record compensation
fully shielded
input section eyeletted printed circuit compact construction ease of
installation price: $111.00 (Walnut, blond, or mahogany cabinet: $19.50)
Write for free catalogue:
ALTE[
LANSING CORPORATION
AUDIO
SEPTEMBER, 1959
ALTEC LANSING CORPORATION. Dept. 9 A
1515 S. Manchester Avenue, Anaheim, Calif.
161 Sixth Avenue, New York 13, N. Y.
A Subsidiary
of Ling Electronics, Inc.
12-71
41
RI
68
stantially mismatched tubes. Two steps
were taken to further guard against
hum. First, we used a ground bus to prevent ground loops from forming in the
K
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22K
R13
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V5
110ma
R18
5600
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+
550 CT
=
1
C6
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40
20
1.5 AMP.
R16
10 K
J2
-6 \0"
3AG
5V
2A
>
4
o
7
8
lX
6.3CT 5A
Fig. 2. Schematic of the simple 10-watt amplifier.
transconductauce, which is rarely the
wise ideal split -load circuit. The balance
control bears special mention. When con- case even for so called matched pairs.
struction is complete, connect the ampli- True push -pull operation requires that
fier to a suitable load, set the control near the output transformer receive equal sigmid -position, and feed a 1000 -cps sine nals from both sides of the circuit.
Since a d.c. balance control is not inwave into the input. Measure the output
and adjust for 3 or 4 volts across the 16- corporated in the output stage, it would
ohm winding. Then adjust the balance be wise to select the closest matched
(total current drawn by both sections)
control for equal a.c. voltages at the
plates of the output tubes. Adjusting for of several 6BX7's. We used a choke in
equal grid voltages is useless; it assumes the power supply, so that hum will be
that the output tubes have identical kept below audibility even with sub-
chassis. The bus is connected to the
chassis only at the input jack. The filter
capacitor must be mounted on an insulating wafer and grounded to the bus.
Secondly, separate prongs on the pre amp socket are connected to the transformer heater winding center tap and
the cathodes of the output tubes. When
no auxiliary equipment is being powered
from the amplifier, plug a shorting plug
(jumpers from pins 6 to 7, and 4 to 8)
into the socket. As well as completing the
primary circuit of the power transformer, this puts a bias of about 23 volts
on the heaters. If a preamp is used, pin
4 can be used as a polarizing source to
connect to the slider of a filament hum
balance control. Aside from these extra
connections, the socket is wired to accept any standard preamp, such as
EICO, Heathkit, or Dynakit. It provides
6.3 volts at 1 amp, and 250 volts at 5 ma.
We cannot emphasize too strongly
that an amplifier is no better than its
output transformer. We selected an
Acrosound TO -250 mainly because it
will deliver 10 undistorted watts from
20 to 20,000 cycles. Negative feedback
can do a great deal to improve frequency
response characteristics and lower internal resistance, hum, and noise, but it
cannot increase power output. As a matter of fact it can decrease useful power
output by accentuating undesirable overload characteristics. If you economize by
using a less expensive output transformer, don't expect to get as much
power at the frequency extremes. This is
an honest 10 -watt amplifier ; try measuring some of the commercial 10- watters
around 20 cps and see how many of them
will deliver rated power in that vicinity.
Figure 3 shows the frequency response
of the amplifier. The smooth, extended
high -frequency range is apparent in
high-frequency transients. The undistorted power output is shown in Fig. 4.
(Continued on page 90)
Ddb= 37 WATTS
+2
c
.4i
.
0
N.
2
-4
-6
-8
10
20
100
00
1000
:0000
,00
Fig. 3. Frequency response of the
amplifier.
10000
1000
FREQUENCY IN CYCLES PER
FREQUENCY IN CYCLES PER SECOND
SECOND
Fig. 4. Curve of power output vs. frequency.
AUDIO
42
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
THE BALLAD
THE SONNET
THE BALLAD, Model A230: Dual 15 watt amplifiers and dual
preamplifiers in a magnificently styled instrument. Friction Clutch Tone Controls: Bass and treble controls adjust separately
for each channel. Once adjusted, the controls lock automatically to provide convenience of ganged operation. Exclusive
Third Channel Speaker Selector: Remarkable new development
permits addition and operation of a third channel speaker in
local or remote stereo systems. Also permits simultaneous operation of virtually any combination of speakers stereo and
monaural in local and remote installations. Illuminated Push Button On /0 f} Switch: Wonderfully convenient device permits
amplifier to be turned on and off without upsetting careful
setting of controls. Speaker Phasing Switch: Corrects for improperly recorded program material. Subsonic Filter: Eliminates phonograph rumble.
-
-
The Ballad, Model A230
.
.
Optional Enclosure, Model AC23
.
.
.
.
$109.95
.
.
7.95
THE SONNET, Model T230: Stereo AM /FM tuner. The ideal
stereo companion for the A230 amplifier. Separate, and Highly
SensitiveAM /FM Sections: Permit superb reception of AM /FM
stereo broadcasts through this one instrument. Multiplex Input:
Conveniently located multiplex jack accommodates multiplex
adapter for receiving Crosby compatible multiplex (FM stereo)
broadcasts. High -Q Ferrite Loopstick: Provides high AM pickup sensitivity. Automatic Frequency Control: Locks each station
into its proper position every time. Improves manual tuning by
a factor of 10 to 1. New Low Noise Front End and Wideband
Transitionally Coupled IF Stages: Result in increased sensitivity
and low harmonic and intermodulation distortion. The T230
features a brilliantly contoured new escutcheon and a superbly
styled new enclosure.
The Sonnet, Model T230
( Complete with Enclosure)
.
.
.
.
$119.95
(Prices slightly higher in the West)
Harman -Kardon Packs More Solid,
Useful Engineering Features Into
The New Model A230 Stereo Amplifier
And The New Model T230 AM /FM Stereo
Tuner Than You Will Find In Most
Higher Priced Tuners and Amplifiers
harman kardon
Westbury, N.
AUDIO
SEPTEMBER, 1959
Y.
43
A "Panphonic" Stereo Control
Amplifier
GEORGE
MANNING LEWIS
A phono preamp of unusual design is combined with an expander- compressor circuit
to compensate for unequal loss of dynamic range of stereo discs as the grooves wear.
DESPITE THE
INCREASED REALISM
of
stereophonic recording and reproduction in home music systems,
many critical listeners are experiencing
disappointment with stereo dises because
of the inequalities in the dynamic range
of the two "channels" that develops,
during repeated use, from the disparate
erosion of the two separate sound producing parts of bile recording groove.
Unlike monophonic records, in which the
gradual loss of dynamic range potentials and the decreasing of the realism
illusion is not unexpected and presents
no great problem, in stereo records (although less in the 45/45's than in the
lateral hill-and- dale's) this disparate
erosion rate -and unequal loss of dynamic range -can result very quickly
in such destruction of the realism and
fidelity that a recording of a brilliantly
conducted symphony becomes a frustrating reasonable facsimile of a Tuesday evening performance by a grassroots- culture- for -everybody music society.
A simple comparison of two identical stereo records, one of which has been
played thirty or so times in normal home
use and the other new, will demonstrate
this to the extent that, if this unfortunate characteristic were not easily correctible, one would doubt that the cost
of stereo records and reproducing systems is justified. Fortunately, however,
*
1802 Atlas St., Murfreesboro, Tenn.
circuitry for the correction of -or ompensation for-such dynamic range inequalities that may develop is fairly
simple to understand and may easily be
incorporated into the design of a two channel preamp or control amplifier, of
the "panphonic" type, without modìification of either the functional flexibility
or monaural uses of the pre- powerLamplifier stages.
Johnson1 some years ago suggested an
effective "expression" circuit by ujhich
variable, selected amounts of volume
compression could be obtained by use
of an ingeniously designed device for
controlling the bias voltage on the grid
of one stage in the control amplifier in
such a way so that the grid bias voltage
varied in proportion to the general
audio levels of the signal; thus increasing or decreasing the amplifying funetion of the stage to provide volume expansion or compression as desired. However, there was, at that time, very little
practical demand for the volume compression features of his circuit, and
since there were equally effective circuits to provide volume expansion which
were simpler and less costly (in components) to construct, few persons other
than experimenters and those having
special needs for volume compression
for recording purposes -and thoset who
must attach every new device, no natter
Maurice P., "Hi -Fi C ntrol
1 Johnson,
Amplifier with 'Expression' " Hi -Fi A umal
and Yearbook, 1956, p. 20.
how weird, to their hi -fi rigs-explored
the potentials of Johnson's "expression"
circuit, despite its immediately apparent theoretical excellence.
Nevertheless, the principles involved
in the basic design and the functions of
the "expression" circuit, are, with some
modification and adaptation, ideally
suited to the problem of compensating
for and restoring the dynamic range
balance necessary to obtain the full realism potentials of stereo discs as they
age with use. Too, when incorporated
into the design of a two- channel control
amplifier, this circuit will greatly en-
hance the realistic illusion of spread sound reproduction of monophonic records and tapes, of AM and FM Radio,
and of certain TV programs (although
a single sound source is usually preferable for most TV programs). Also with
proper switching arrangements the "expression" circuit will contribute as much
to the increased realism of the (pseudo)
stereophonic AM -FM and AM -TV simultaneous broadcasts now available in
most communities, as to the enjoyment
of stereo records; and should therefore
be incorporated into a "panphonic"
type control amplifier which allows two channel reproduction and control of
signals from a single (monophonic)
source or signals from various combination (stereo) sources. Such a control
amplifier is represented in the schematic,
with variations in the "expression" circuit represented in an alternate schematic, Fig. 2.
Construction
The pauphonic control amplifier, Fig.
constructed for the author's use
in his home system and is designed for
use with a Pickering stereo cartridge
and with two 35 -watt Williamson -type
power amplifiers. Modification to meet
the needs of ceramic cartridges is fairly
simple and may be provided for by the
inclusion of two closed circuit input
jacks as suggested in the "alternate input switch" arrangement in the insert in
1, was
VOL
CONTROL
Fig.
I.
The
au-
-
amplifier
constructed to
thor's
SS
CONTROLS
cH.
t
mount on a standard rack.
2
CH: t
CH. 2
CYIDIAT.AIC RANGE
Fig. 1.
Since the signal output of most magnetic pickups is very low, in order to
afford sufficient amplification in the pre-
!
EQUALIZER
NTROLS
CONTROLS
AUDIO
44
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
Early American Model,
in fruitwood,
30" wide, 24%" high, 13%" deep.
$279.95 user net.
s
r
E
Furniture courtesy of Lopipero Inc.
TMS -2... most sensational advance in stereo reproduction
BALANCED
STEREO
ANYWHERE
THE ROOM
Containing two complete multispeaker
systems in one compact enclosure, the
'Trimensional' TMS -2 projects frequencies
of both channels to the rear and side walls
of the room. Thus, one large wall area
becomes channel A; another channel B...
exactly as if you had a series of widely
distributed speakers for each channel.
When you .listen to the TMS -2, ÿou will experience stereophonic
reproduction that no conventional system can ever achieve. Its entirely
new principle of operation permits every listener throughout the
room to enjoy fully balanced sound with such extraordinary breadth
and Three-dimensional depth that it seems to originate beyond the
confines of the room itself. Full controls and adjustable doors allow the
`Trimensional' TMS -2 to be placed anywhere
along wall or corner without affecting its
performance capabilities. The full TMS -2
story is a fascinating. one. Write for it today.
-
Furniture courtesy of Jens Risom Design Inc.
Contemporary Model,
30" wide, 25" high, 12'/y" deep.
In mahogany $258.00,
in blond or walnut $263.00 user net.
-
-
WRITE DESK R -6, UNIVERSITY LOUDSPEAKERS, INC., WHITE PLAINS, N. Y.
AUDIO
SEPTEMBER, 1959
45
section is about 185 it is reduced by the
equalizer feedback to approximately
1.85. The over -all gain of the two sections is therefore sufficient to activate
the "expression" circuit and to meet the
requirements in signal strength of the
power amplifier. (V,, and V4 barely
amplify the signal sufficiently to compensate for loss in the tone controls, and
hence for all practical purposes in construction may be disregarded as signal
jectionable, and if metal octal type
tubes are preferred -and if one does
not mind the addition of another tube
combination of
to the preamp stages
one 6SC7 and two 6SJ7's can be used by
devoting each triode of the 6SC7 to
separate stereo channels, coupling the
section plates to the separate pentodes
for the necessary second stage of the
preamp to permit a feedback type of
equalizer and still have sufficient gain
to activate the "expression" circuit.
In any arrangement it is important,
however, that the triode stage precede
the pentode stage since a gain of more
than 50 is needed in the preamp for
stereo reproduction. By using the 61.18's
as shown in the schematic one may expect an over -all mid -band gain from the
first (triode) section of 25 -30; and although the over -all gain of the pentode
amp stages without using more than one
tube -envelope for each of the stereo inputs and to allow for the loss in the
equalization circuit, two 6U8 tubes were
employed, although these tubes are comparative newcomers to the audio field
and have, when new, greater micro phonic tendencies than some of the usual
types used for preamp circuitry. With
care in wiring, sufficient cathode bypassing, and shielded grid leads whenever more than an inch in length, if
properly mounted and placed on the
chassis for a minimum of mechanical,
external vibration, 6U8's may be operated with almost complete absence of
noise. Certainly with as little noise as
the favored 6SC7 preamp tubes used in
some circuits.
However, if the microphonic tendencies of the 6U8 tubes are considered ob-
-a
amplifiers)
.
Equalization Network
The equalizer circuit preferred for
use with 6U8's is of the "between stages"
network type, and although other arrangements for obtaining the exact
equalization required for optimum reproduction are possible, they will gen(Continued on page 86)
B.
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6U8
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PICKUP INPUTS
T. R.
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FM
TV
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ALTERNATE INPUT SWITCH
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6V
s
e
s
8
Fig. 2. Over -all schematic of the panphonic amplifier.
AUDIO
46
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
the "fourmost reasons" why Audax Paraflex*
is not `just another speaker system."
George Silber,
as President of Pek- O -Ktat and it new Audax Division has been a
pioneer in the manufacture of the highest quality components. In Audax Speaker Systems.
you will find the same uncompromising standards that have made Rek -O -Kut StereoTables
the most respected brand in high fidelity.
Saul White, well known design engineer and writer
on transducers and inventor of
the patented Paraflex foam compound suspension, the greatest step towards the reproduction of natural sound.
Tom Mulligan, representing the
great Union Carbide Company who researched and
developed the Dynel fabric adapted by Audax for its "Acoustiscreen."
George Nelson,
one of America's greatest industrial designers, brilliantly styled the
enclosures and developed the Dynel three -dimensional " Acoustiscreen" grille.
Two MODELS new at your dealer's
-
CA -80
System, 12"
x
12"
x
24",
$99.9 CA -100
System,
15"
x
12"
x
25
$139.95.
AUDAX
Export. Morhan Exporting Corp., 458 Broadway, New York 13, N.Y. Canada Atlas Radio, 50 Wingold Avenue, Toronto
AUDIO
SEPTEMBER, 1959
19,
Ontario
RA8
47
QUI PME NT
Pilot SP -216 -A
Control Unit
Preamplifier -
University Model TMS -2 "Tri mensional" Stereo Speaker
-
Leak Amplifier Line
"Point One" Stereo and Mon-
The
ophonic
Dynaco Stereo 70 Power Ampli-
fier Kit
PROfi I
PILOT
SP -216 -A
DELUXE
STEREO PREAMP- CONTROL
UNIT
When the Pilot SP -215 stereo preamplifier and control unit appeared on the mar-
ket last year, we reported it briefly in these
pages in conjunction with the SM -244, a
complete stereo amplifier-preamp unit. It
was then described as being "extremely
flexible, well engineered, and carefully
built," and after a year of use we are of
the same opinion still. Its successor, the
SP- 216 -A, is an "improved" version of the
same basic unit, which is somewhat like
painting the lily, since the earlier model
was sufficiently excellent to satisfy most
users.
However, careful study of the SP -216 -A
brings out the points of superiority of the
new model, both from the standpoint of
user convenience -which is obvious to the
eye -and to the reduction of the already
low distortion throughout the circuit, which
is not so obvious on casual inspection. In
general appearance the new model is not
radically different, in spite of the more
attractive finish of panel and frame, the
latter being heavily gold plated and highly
polished. The knobs are also gold plated,
and the over -all appearance is quite luxurious. The cabinet is steel, with a black
grained vinyl covering permanently bonded
to the metal.
Basically, the circuit consists of two
identical sections comprising a dual- triode
preamplifier, tone -control amplifier, and an
output cathode follower. Side amplifier
circuits feed from the selector switch
through separate volume controls, another
amplifier, and a cathode follower to feed
a tape recorder, with a tube -driven VUtype meter indicating the recording level
being fed to the tape machine. In addition,
a panel -mounted switch connects both metering circuits to the audio output terminals to facilitate balancing the two channels for stereo reproduction.
The 216 -A has a total of 14 inputs
seven pairs for phono changer, phono
turntable, tape head, microphone, tuner,
multiplex, and tape amplifier. These inputs are selected by a rotary switch, except for the change from changer to turntable, which is effected by a slide switch
along the lower edge of the control panel.
Equalization in the preamplifier stages is
provided from feedback circuitry in the
216 -A, whereas in the 215 equalization resulted from a between -stage losser network. Because of the feedback, the new
circuit has less distortion than before. The
function switch has four positions, the
usual stereo and stereo reverse, and monophonic output from either channel A or
E
channel B inputs. The ganged master volume control is in two sections (four pots
altogether), one immediately following the
selector switch and one in the grid circuit
of the output cathode -follower stage. Thus
any hum or noise which might originate in
the tone -control stages is reduced as the
output level is lowered, while the input
section of the control prevents overload of
the intermediate stages in case of higher than- normal input levels. The volume controls of the two channels track within 2 db
over the majority of the range. The loudness-contour switch is ganged for both
channels, and provides a normal or flat
position, and four separate contours for
correspondingly reduced levels. Dual -k ob
potentiometers are used for both bass nd
treble tone controls, permitting seps ate
adjustment of tone in the two channels.
The knobs may be locked together with the
eexclusive Pilot "TroLoK," a simple
chanical means for coupling the knobs for
simultaneous control of both channels. he
power switch has three positions-oN, OFF,
and AuTomatic, and in the latter position
the cutoff switch on a record changer lean
serve to turn off the entire amplifier system. The remaining panel control is for
balancing, with one channel being eut off
at each extreme of rotation.
The rear apron mounts two dual level set controls, together with a ganged control for recorder output. This permits adjusting the recording signal to any level
from 0 to 1.3 volts at zero indications on
the two meters. This is extremely desirable because it enables the recordist to operate with normal meter swings regardless
of what level his tape recorder requires.
When switched to the MONITOR position,
the meters indicate the audio output level,
and the user then adjusts the balance con-
trol to get equal outputs.
Frequency response was measured at a
1 -volt audio output and was found to be
within ± 1.3 db from 20 to 20,000 cps.
Minimum input signals for a 1 -volt output were: tape head, 1.9 mv; phono, 3 mv;
microphone, 2.8 mv; and for the high -level
inputs, 0.11 volts. Hum and noise measured at 82 db below 1 volt on the high level inputs and 66 db below 1 volt on the
low -level inputs with volume control at
maximum. D.c. is used on the heaters of all
the audio stages (not the side amplifiers
nor the meter amplifiers) and over supply filtering is generous so that hum is
never a problem with this unit.
Listening quality with the 216 -A is
slightly better than the earlier 215, although unless they were played side by
side the difference would scarcely be noticed. On the debit side -and it is difficult
to find anything about the unit with which
one could find fault -is the lack of a
phasing switch, and possibly the lack of
several different equalizations for older
records. We modified the 215 to provide
the phasing switch, and could easily do so
with this one if we considered the need
sufficiently important. As to other equalizations, the tone controls are marked to
indicate the approximate settings for
NAB, LP, and AES curves, which should
be adequate for anyone. The serious experimenter will find the 216 -A ideal for recording and for general "tinkering" where
a meter is desirable. Many of these pre amps are being used in broadcast stations
for record reproduction, and we believe
that an optional satin chrome panel for
rack mounting might engender still more
interest in professional applications. At
least, the unit is good enough for such
J -10
uses.
-
Fig. 1. Pilot
SP-216
-A Deluxe Stereo Preamp.
AUDIO
48
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
a new tweeter that solves at least
three of your speaker problems!
.'"
........
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SOUTH AMERICAN TROUPIAL BIRD PHOTOGRAPHED AT TREFFE ICH'S, NEW YORK
the ah!* electrostatic transducer
15Y/a"
A Combination Mid -Range and Super Tweeter
The 'ah!', because of its revolutionary new construction gives clear, transO
parent response on all frequencies from 600 cps to beyond
the limit of audibility
and has none of the limitations of tonal coloration and exaggerated peaks found
in cone or piston type tweeters!
The `ah!', because of its omni -directional characteristics, offers tremendous
advantages in your stereo system. The `ah!' enables you to space out speakers
to achieve the dramatic effects associated with wide separation without the
disturbing "hole -in- the-middle" caused by the directional characteristics of
conventional speakers
or by single- ended, high distortion, limited range
electrostatic speakers.
The 'ah!' electrostatic transducer is superior in quality and performance to
speakers selling for almost twice as much, but, because of expert research
facilities and newly developed materials it is offered at an unprecedented low
price ... only $49.95.
Nothing else to buy R/C crossover network and
AC power supply are built in. 8 or 16 ohm L pad
may be added to attenuate tweeter, if desired.
©
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©
-
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*An American -made speaker
patent
applied for by COSMOS INDUSTRIES-
/
GUARANTEED FOR FIVE FULL YEARS,
elements are practically indestructible.
the 'ah!' electrostatic transducer can now be seen at WEST COAST
HUDSON
RADIO
48 West 48th Street
New York City
212 Fulton Street
New York City
35 Witham Street
Newark, New Jersey
AUDIO
LEONARD RADIO
69 Cortlandt Street
New York City
HARVEY RADIO
103 West 43rd Street
New York City
IN THE
MIDWEST
Allied Radio Corp
Voice & Vision Inc.
921 N. Rush Street
Chicago 11, Illinois
.
100 N. Western Avenue
Chicago. Illinois
SEPTEMBER, 1959
See your local
AT THESE ALLIED HIGH FIDELITY STORES
Voice & Vision Inc.
7055 W. North Avenue
Oak Park,
Illinois
Evergreen Allied High Fidelity Inc.
2025 W. 95th Street
Chicago, Illinois
high -fidelity
dealer.
Allie High Fidelity Stores
602 Davis Street
Evan ton,
Illinois
73/4
Mates easily and quickly to any speaker made.
Frequency Response: Full flat, lifelike midrange
plus UHF coverage -600 cps to past the limit of
audibility. Roll off 6 db /octave of speaker and
crossover network below 900 cps. Backwave
completely undamped.
Impedance: Designed to match 8 or 16 ohms
output of 15 to 50 watt amplifier.
Crossover: Self- contained R/C crossover network; recommended crossover point between
650 to 850 cps. May be connected in parallel
directly across any low frequency woofer with-
out additional network.
Sound Dispersion: Full 180° coverage (front and
backwave) when speaker is mounted at least
6" from back wall.
Distortion: Practically unmeasurable. Radiation
area is 62 sq. inches.
Polarizing Voltage: Fused currentless 1000 volt
DC power supply. 110 volt AC power line.
Hand rubbed genuine walnut cabinet, other finishes available on special order.
For complete information and
specifications write to:
COSMOS INDUSTRIES, INC.
31 -28 Queens Boulevard
Long Island City 1, New York
49
in the room.
Figure 2 shows the TMS -2 as it is used
for stereo. The two doors are opened outwards to screen leakage directly forward
from the two high- frequency sections so
that all the sound from them reaches the
listener in the form of reflections. For
various placements in the room, the positions of the doors may need to be varied
for optimum effect, but that requires only
a little experimentation. For monophonic
listening, the doors are closed, resulting
in a more normal type of single -channel
Fig.
2.
University "Trimensional" stereo speaker system with the "doors" opened for
stereo reproduction.
UNIVERSITY "TRIMENSIONAL"
STEREO SPEAKER, MODEL TMS -2
One of the principal problems in laying
out a satisfactory loudspeaker system for
stereo reproduction in the home is the provision of adequate space in the right places
for two separate loudspeakers -completely
aside from the fact that in many homes it
is difficult, if not impossible to obtain sufficient cooperation from all members of the
family to put the speakers where they
should be regardless of the appearance.
Loudspeaker cabinets have not been around
long enough for us to have acknowledged
their snob appeal as we do with the architectural monstrosity known as a grand
piano, yet space will be made for one of
these even though it may never be played
but serve only as an ornament. Aside from
the problem of space for two cabinets,
there is also the problem of cost. There
are, undoubtedly, some people in the world
to whom the extra outlay of a few hundred
dollars for another loudspeaker system may
not upset the budget, but this is not a universal condition.
Understandably, therefore, speaker manufacturers have introduced many types of
speaker systems aimed at the largest section of the home market -both with respect
to price and to acceptance. Practically all
small cabinets have been presented as
"ideal for stereo," but they had nothing
special to offer except their small size, and
while many gave excellent account of themselves as to the performance, two were still
required, and in most instances they were
simply rectangular speaker enclosures just
like their larger counterparts in appearance but perhaps half as big.
Another solution-which appears to
work quite well -is to use a single woofer
which reproduces the low- frequency portion
of both channels and a small separate
speaker for each channel to reproduce the
high -frequency portion. When properly disposed in the room and properly phased,
this system works well, and if the crossover
is sufficiently low-that is, not over about
600 cps -the stereo effect is satisfactory.
Two different methods of combining the
low- frequency outputs of the two channels
have been used-in one an isolating net-
work couples the two systems together in
additive phase, while in the other a dual
voice coil is used with the two electrical
outputs being fed to separate voice eoils
on the same former and driving the same
cone. Thus motion will be imparted to the
cone in direct proportion to the vector sum
of the two signals.
The principal advantage of this system
is that a dual- voice -coil woofer costs my
slightly more than a single conventi$nal
unit of the same size, not two times as
much as two separate speakers do.
The next step in developing a single -unit
stereo speaker is the placement of the high frequency units for proper dispersion. Unless the cabinet is at least six feet long,
the speakers can not be placed far enough
apart for good results, if they are to face
the front. If they are made to radiate but wards from the ends of a smaller cabinet,
then reflections from the walls can create
a spatial feeling. Regardless of where one
is in the room, there are many path; of
reflection coming from each channel. This
is what the University TMS -2 purportis to
do, and does.
When we first heard this unit it was
being demonstrated in a room about 15 eet
wide and 30 feet long. Across one of the
narrow ends a scrim was placed so we
could not see the speakers being AB'd
against each other. We learned later that
one condition comprised two S -10 speaker
systems spaced about 8 feet apart; the
other was the TMS -2. Some form of screen
is always a great advantage in a stereo
speaker system, for it is a human characteristic to hear two sound sources i we
can see two. You can prove this to you self
with any two -way system. Take off the rill
cloth so you can see two speakers, and they
will seem not to blend together at the crossover as they should, but will appear to be
separate sources. Cover them and you again
hear only one apparent source.
With the TMS -2 system, you always had
the feeling of good stereo reproduction in
every part of the room; with the ,two
5 -10's, either channel would seem to predominate as you came closer to it. We have
since lived with this speaker for some
weeks and the illusion persists -the stereo
effect is excellent no matter where you are
1
sound.
The system consists of a heavy -duty
12 -in. dual- voice -coil woofer which covers
the range up to 150 cps, and two separate
high -frequency sections, each employing
an 8 -in. midrange cone and a wide -angle
compression -type tweeter using a 3000 -cps
crossover. The woofer section is ducted,
with both cone and port projecting sound
out the back of the unit. The high-frequency sections project the sound from the
ends of the cabinet to the right and left.
While it is only of academic interest, we
tried the speaker outside in an area well
away from any reflecting surfaces, and the
stereo effect was very well suppressed,
with the over -all reproduction sounding
quite dull, as would be expected. None of
this was observed in a typical room, however, unless the speaker were placed where
drapes absorbed the side -projected sound,
in that case the stereo effect again suffered, and reproduction was dull. But in
the average room the stereo effect was
always good, and no hole in the middle
was observed once the phasing was correct.
As to range, reproduction without doubling
was heard down to 32 cps, and the controls
provided allowed for a well -balanced overall range.
J -11
THE LEAK AMPLIFIER LINE
paragraphs.
Preamplifiers
Three preamplifiers are now available
two for monophonic and one for stereo. The
"Point One Plus" employs two EF86's (or
Z729's or 6267's), has inputs for tuner,
tape, and four phonograph equalizations;
it has bass and treble tone controls, a volume control, and a filter control, -the lat-
-
AUDIO
50
www.americanradiohistory.com
AmericanRadioHistory.Com
-
STEREO AND MONOPHONIC
Once upon a time there was only one
Leak amplifier available in the U. S.-the
TL /12, with its preamp. It was called the
"Point One," referring to its distortion at
rated output. There are now five power amplifiers and three preamp -control units,
and they are still called Point One for the
same reason as before.
The TL /12 Plus has a maximum output
of 14 watts with 0.1 per cent distortion at
12 watts, frequency response flat within
± 0.5 db from 20 to 20,000 cps, and a damping factor of 25. The 12 -watt output is
obtained with an input signal of 125 mv.
Two EL84's are used in the Ultra- Linear
output stage, and the amplifier can feed
loudspeakers of any impedance between
3 and 20 ohms.
The TL /25 Plus has 0.1 per cent distortion for an output of 25 watts, while other
specifications remain the same except for
the output stage which employs two
KT66's. Maximum output is 32 watts.
The TL /50 uses KT88's, and its distortion is 0.1 per cent at 50 watts. Other
specifications are the same.
The "Stereo 20" is essentially the same
as two TL/12's on the same chassis, and
the "Stereo 50" is almost the same as two
TL/25's on the same chassis. This model
is described more fully in the following
SEPTEMBER, 1959
START YOUR NIGH FIDELITY SYSTEM
WITH A GRAY COMPONENT
ASSEMBLED
...GRAY COMPONENTS for expert workmanship at
GRAY Hysteresis Synchronous Turntable Kit
GRAY Custom
that give you all the extras you
need for the most complex system.
33 H (Hysteresis- Synchronous)
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.. 17.95
GRAY Tone Arm Kit
,
; ..
Deluxe turntable, arm and base
Factory assembled components
Precision engineered parts.
Balanced for both stereo
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HSK -33 turntable .. $49.50
SAK -12 tone arm.. 23.95
TBA base
low cost to you
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Turntable
212 SX 12" arm
33
C
Wood Base
$79.95
34.00
23.95
GRAY Micro - Balanced Pressure Gauge
Indicates pressure on record
surface so that adjustments
can be made for proper tracking. A true balance without
springs.
PG 200 gauge
$2.50
Outstanding features such
as linear fluid damping,
quick- change cartridge
slide, adjustable static
balance, and versatile wiring for all cartridges makes SAK -12 tone arm your best buy.
SAK -12 12" arm kit
$23.95
Visit your friendly quality Gray dealer for a full demonstration. Write to its for complete literature.
our 67th year in communications ..
GRAY
AUDIO
SEPTEMBER, 1959
.
High Fidelity Division
DEPT.
X
16 ARBOR STREET, HARTFORD 1, CONN
51
of any thickness, a cutout 37/s x 10% in. is
made and the preamp is inserted from the
front. Then a U- shaped bracket is placed
over the amplifier and secured firmly with
a wing screw into a threaded bushing in
the back of the preamp. Power and signal are furnished to the power amplifier
through a single 6-conductor cable, while
the a.c. line is fed to the switch through a
separate shielded pair.
Stereo 50 Power Amplifier
Fig. 3. Leak "Point One Stereo"
preamplifier, deriving its power supply from
power amplifier.
ter providing a low -pass filter at 4000,
6000, or 9000 cps, as well as an off position.
Two jacks are mounted on the panel for
use with tape recorders -one to feed the
recorder and one for replay. The input
sensitivity is 9.5 my for rated output, 125
mv.
The " Varislope III" has all the same
features as the "Point One Plus," and in
addition has a control which varies the
slope of the cutoff filters over the
range from 5 to 35 db per octave. It also
has a slide switch for selecting between
two pickups so the user with both changer
and turntable has a panel control between
the two so as to eliminate the need for
plugging in or out cables when changing
from one listening mode to the other. A
rumber filter is also provided, with a cutoff at 70 cps. The jacks for use with tape
recorders are retained with this model.
The "Point One Stereo" preamp, Fig. 3,
is essentially the same as the "Point One
Plus" except it is in duplicate, but with
the addition of the rumble filter and the
necessary function switch. Connections to
the tape recorder are made at the rear
rather than through panel -mounted jacks.
Using only two tubes, the circuit arrangement of the "Point One Stereo" is
considerably different from typical U.S.
preamps. All input signals are fed to the
grid of the first tube through level -set
controls except microphone and tape head,
and the phono and tape head equalization is
provided by feedback around the first tube,
a pentode. Gain is reduced for the high level inputs by using only resistive feedback, while the equalization is achieved
with reactive networks in the feedback
circuit.
Following the first stage is the tone control network-the Baxendall type. In most
circuits, the Baxendall network is used between two triodes, but when used with the
pentode sufficient gain is obtained to permit operation wth only the two tubes in
the entire preamp. The balance control follows the second pentode, and it is followed
in turn by the rumble filter and the volume
control. Output is not from a cathode follower, which is almost standard in U. S.
designs, but the average output impedance
is about 37,000 ohms. A 4 -ft. cable is used
to connect the preamp to the power amplifier, and extensions are available up to a
maximum of 16 ft., so the output impedance does not appear to create any problem.
a Leak
From the specification standpoint, the
input impedance on phono ranges from
70,000 to 100,000 ohms, depending on the
position of the level-set control, and the
input signal for full output (125 mv) is
5 mv. On the microphone input, the input
impedance is 120,000 ohms, and the required maximum signal is 3 mv- adequate
for practically any high-impedance microphone, although crystal and ceramic units
may find the input impedance too low for
normal bass response. The tape -head input
has an impedance of 120,000 ohms, and
full output may be obtained from an input
of 4 mv. The high -level inputs have an impedance of 70,000 to 100,000 ohms, with a
50 my signal being sufficient for full output. The bass controls give a range of ± 16
db at 30 cps, and the treble control provides a range of ± 14 db at 20,000 cps,
Over -all distortion at normal output is
less than .01 per cent, and hum and noise
measured 55 db below one watt when used
with the "Stereo 50" power amplifier on
the high-level inputs, and 52 db below 1
watt on phono and tape -head inputs.
Mounting of the "Point One Stereo" preamp is simple and effective. Using a panel
The Stereo 50, shown in Fig. 4, comprises two identical amplifiers employing
EL34's, KT66's, or 5881's in the output
stage, which is of the Ultra- Linear type.
Output-stage bias is obtained from separate cathode resistors for the output tubes,
each being bypassed by a 50 -µf capacitor.
The phase splitter is of the "long- tailed
pair" type using a 12AX7, while the first
stage is one half of another 12AX7 -the
two sections of the amplifier sharing one
tube. Feedback returns from the secondary
of the output transformer to a tap on the
cathode resistor of the first stage, and the
output impedance is selected by a movable
plug arrangement on the transformer itself. A similar arrangement serves to select
the input tap on the power transformer,
with values of 110, 117, and 125 being provided on U. S. models to accommodate
different line voltages. The British models
have input voltages of 205, 225, and 245
volts. The design of the amplifier is such
that it is not critical as to balancing of
output tubes, and only a slight change was
noted when tubes of widely different mutual conductance were used in an output
stage.
In general, observers have noted that
there is a different tonal quality to British made amplifiers. The reason for this is
hard to explain, since measurements are
not appreciably different from many domestic amplifiers of equal quality. One
might say that there are some things we
have not yet learned to measure, which
seems doubtful. However, one must admit
that the Leak amplifiers have a definite
cleanness of tone which makes them a
pleasure to listen to, a crispness usually
associated with very low distortion. Regardless of the reason, we find that the
Leak equipment has little or no coloration
of its own, and it is convenient to use and
J -12
of ear- satisfying quality.
the
Fig. 4. The Leak "Stereo 50" power amplifier, a pair of 25 -watt amplifiers on
same chassis.
AUDIO
52
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
A professional quality tweeter
use In 2 -way speaker systems
for
ex-
ceeds 3 -way systems and gives you
a complete high fidelity reproduction even in lack of a mid -range
unit.
As this tweeter has a large power
handling capacity and a very low
crossover frequency, you can save
your money by omitting a midrange unit and enjoy flat response
over wide range.
Pioneer offers PT -5
Features:
Having large power handling capacity,
this tweeter gives you an excellent per-
formance when used as home hi -fi sets,
theatres and auditoriums sound systems.
Being
adopted
a
comparatively low
crossover frequency, it
is
not necessary
to use a mid -range horn and worry about
the troublesome distortion, which often
occurrs between 2,000 and 3,000 cps.
A peculiar rectangular exponential horn
of thick diecast material gives you clear
sounds free from rattles.
The diaphragm is of a special polyester
film molded under heating process, which
enables to endure high temperature and
humidity free from any changes
teristics.
in
charac-
Best suitable Pioneer's professional woofers
assembled with
PW -30C
PW -38C
PT -5
tweeter:
pioneer
Specification:
Model No.
PT -5
Power handling capacity 35 Watts
Voice Coil Impedance :
16 ohms
Frequency range
600--16,000 cps
Sensitivity:
108 db
Cutoff Frequency:
600 cps
Crossover Frequency:
1,200 cps
Total Flux:
73,000 maxwell
Flux Density
13,500 gauss
Weight :
5.4 kgs. (11.9lbs.)
:
:
:
Front Dimensions:
Depth:
AUDIO
SEPTEMBER, 1959
7',"
1
x 5 -,,"
6 y,,,
53
THE FISHER
a
?.,
INCLUDES THE FOLLOWING:
FISHER X -101A
_
:i
il
_,4
Stereo Master Audio
Control and Duplex
Amplifier -the
world's most versatile control amplifier! 40 watts in stereo
operation; peak power. 75 watts. 12 inputs. 8 controls, plus 6 chassis adjustments. 8- position Input Selector: 78, LP,
RIAA -2, TAPE, TUNER, AUX -1,
4- position Output Selector: Reverse, Standard, Channel A -; -B and Channel B-1 -A (for two-speaker monophonic
operation.) Separate Bass and Treble conRIAA -1,
AUX -2.
trols for each channel. Record -Monitor
facilities. Rumble filter. Provision for
all stereo and monophonic program
sources, present and future. $194.50
70" power amplifier kit with its protective cover.
struetion required is to mount the pacts,
DYNAKIT STEREO 70
connect plate and heater windings as well
POWER AMPLIFIER
as the power and output transformer leds,
Carrying on the tradition of high quality and make a few connections to the printed
at a considerable saving over an equivalent circuit boards. Average construction time
unit in factory -built form, Dynaco now is said to be about 5 hours, but we did
has a dual power amplifier which serves ad- somewhat better than that, as would anymirably for a home stereo system. Essen- one who had previously built any electronic
tially duplicating the original Dynakit equipment.
Mark II amplifier in specifications, the
In any modern amplifier of good quality
Stereo 70 comprises two identical channels it is now expected that frequency response
stages.
the
output
in
EL34's
employing
be flat within ± 1 db over the entire
Working at slightly less power supply volt- will
spectrum from 20 to 20,000 cps, and
audio
maximum
the
II
reduces
Mark
the
age than
was
the ease with the unit measured.
such
slight
degree
to
a
but
only
output,
power
less than 0.2 db difference beThere
was
50
than
1.6
less
only
db
is
since 35 watts
the
two channel responses at 20 cps
tween
6,
Figs.
5
and
in
shown
This
unit,
watts.
and less than 0.3 db difference at 20,000
is completely enclosed in a protective
cps. Damping factor is rated at 15, which
Dynakit
prefor
power
screen. It provides
was borne out by a measured sourceimrequireof
similar
others
amplifiers or for
of 1.1 ohms on the 16 -ohm tap.
pedance
for
primarily
intended
ments, and while
0.9 per cent IM distortion at
measured
We
can
two
channels
stereo installations, the
sine wave power with
watts
equivalent
35
a
convenient
by
be connected together
2 -per -cent point appearing at 41 watts.
the
chanto
a
single
switch to furnish 70 watts
measured at 71 db below
nel. Output impedances of 4, 8, and 16 Hum and noise
1 watt with the input shorted, which is exand
on
channels,
both
ohms are available
good for a high -power amplian input signal of 1.3 volts is required for ceptionally
is somewhat better than
figure
This
fier.
a full 35 -watt output.
II amplifier but the
Mark
original
the
III
models,
As in the Mark II and Mark
a choke in the filter
model
employs
newer
a
each channel of the Stereo 70 employs
III.
Mark
the
as
does
circuit,
triode -pentode and two output tetrodesThe amplifier runs cool, and with the
in this model EL34's being used. The trilower plate voltage should "coast" at any
ode-pentode is a 7199, and all of the difficult wiring of the voltage amplifier stages normal output requirements. Listening
-pentode for the input stage and the tri- quality is clean, and the unit has no quirks
is completely stable under
of operation
ode for the split -load phase- splitter -is
already performed on a printed circuit fur- all conditions to which we have been able
J -13
nished in the kit. Thus about all the con- to expose it.
Fig. 5. Dynakit "Stereo
-
-it
Fig. 6. The Stereo
70 with cover re-
moved
to
show
printed circuit
unit, which is furnished already
wired.
Cabinet
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AUDIO
54
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SEPTEMBER, 1959
YOUR GATEWAY TO PERFECT STEREO
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Export: Morhan Exporting Corp., 458 Broadway, New York 13, N.
AUDIO
SEPTEMBER, 1959
Y,
55
oA«i&tkaL
CHARLES A. ROBERTSON*
STEREOPHONIC
The Famous Castle Jazz Band in Stereo
Stereo Records S7021
Castle Jazz Band: The Five Pennies
Stereo Records S10037
One of the early outposts in the traditional
jazz revival was Portland, Oregon, where a
resolute bunch of semipros gathered under the
captaincy of Monte Ballou in 1948. They
manned a cooperative venture called the
Castle Jazz Band until 1950, when divergent
vocations sent them along separate paths.
Left behind was a small legacy of 78 -rpm
records, treasured by collectors but not suitable technically for release on LP's. Two recent reunions, held with the full benefit of
stereo in the studios of the Good Time Jazz
label, remedy this situation and find the
original sextet reclaiming many happy memories and all its youthful enthusiasm.
Still vocalist, banjos, and guiding spirit is
Ballon, who commemorates the first meeting
with a heartfelt delivery of Tommy Lyman's
The Torch, better known as When the Gang's
AU Gone. Both he and Bob Gilbert, the clarinetist and an advertising executive with General Electric. are back in Portland and play
together weekends. Trombonist George Bruns
is a musical director at Walt Disney Studios,
busily coining The Ballad of Davy Crockett,
and other hits. Drummer Homer Welch is
employed in San Francisco radio, and pianist
Freddie Crews works as a single in Bay Area
clubs. Currently the Firehouse Five Plus
Two's tubaist, Don pinch, returns to trumpet,
while Bob Short, most recently cornetist with
Turk Murphy, is back on tuba.
A clue to the band's leading characteristic
is the versatility acquired by several members. While not fully detailed in the roll call,
enough evidence is given to indicate the
thoroughness with which they pursue the
basic truths of New Orleans style. Each
musician is not only able to anticipate the
others but, most likely, is capable of assuming
their parts. The ensembles are played with a
togetherness that completely transforms Sylvia Fine's four new songs for the Red Nichols
saga. All the lavishness of the screen production and the sentimentality of other performances are stripped away. The remaining
melodies are reexamined in the light of the
period they are supposed to represent and
made to sound as though they were written
by Jelly Roll Morton.
The same principles of collective creation
are applied at length to eight dixieland reliables, no matter how briefly they are introduced in the picture. Included are Indiana,
the cornetist's trademark, Battle Hymn of the
Republic. and the Castle's own distinctive
marching on the a:nts.
They undertake to restore a dozen of their
older recordings with the benefit of modern
sound at the first session. So deeply engrained
is the feeling for ensemble interplay that the
years they were apart do nothing to lessen
its intensity. Seemingly reluctant to forego
the satisfaction of working as a team, they
would maintain a classic diffidence toward
soloing unless Ballou urged them on. Any
inhibitions are dispersed by his disclosure
*732 The Parkway, Mamaroneck, N. P.
en
luit Ft.(' Been floating Down the Old
Nicer, and the others clambered aboard to
test the current on Srnoky Mokes, Feretoell
Blues and Kansas City Stomps. Functional and
to the point, the solos never outlast their
welcome or become boring. Gilbert proves that
General Electric's gain is a loss for jazz.
The stereo spread allows ample room for
the rhythm section, while avoiding a ping pong effect from the horns. The monophonic
versions are available on Good Time Jazz.
Jo Jones Plus Two
Vanguard Stereolab VSD2031
More Drums On Fire!
World Pacific Stereo 1022
On these exciting drum romps, the solo
prowess of Count Basie's first drummer is
brought into direct comparison to that of hie
latest in the line of succession. Jo Jones i
heard with his current trio, his collaborators
being the Bryant brothers from Philadelphia
-Ray on piano and Tommy on bass. Together they have worked up five stunhing
originals, and four standards which include
Satin Doll, Sweet Lorraine, and Sometimes
I'm Happy. The great strides made by Jones
since being relieved of the necessity to rive
a big band are everywhere evident.
my
Shelly Manne can also create, with equal
discretion and swinging beat, a small orchestra from drum and cymbal timbres. In
ticking of the rhythms on Cubano Chant, he
makes no recourse to the usual Latin American trappings, relying on his own setup to
obtain a percussive sound which is unique
for such excursions. Some of the freedom he
now enjoys is due to the strong left hand of
his pianist. and Jones need waste little effort
on the fills and backing required in most
trios. Ray Bryant's performance on two 'dues
is dynamic and masterful. When considered
with his set of blues solos for Presige, in will
cause his stature to rise considerably in Many
I
eyes.
One of Sonny Payne's current display pieces
with Basie is Old Man River, and Jones presents his version in a sustained solo. Payne
responds in kind at a World Pacific session
held while the band was in Los Angeles, playing Clap Hands Here Come Charlie. As to a
decision, you'll be too limp to make one The
other items on the anthology, the second in a
series, feature Mel Lewis' brushwork on a
blues, Benny Barth of the Mastersounds and
Armando Peraza and Ray Mosca of the Gorge
Shearing group. The last pair make a duet
of Stan Kenton's Artistry in Rhythm, giving
it a more musical reading than some bands,
and Peraza's conga drums encore with Freddie
Gambrell on Triste. In every case the drums
are well placed in stereo.
Buddy Bregman: Swingin' Standards
World Pacific Stereo 1024
Ray Anthony: Sound Spectacular
Capitol ST1200
These fine dance sets from the West Coast
are distinguished by a big sound and a multitude of stereo attractions. Buddy Bregman's
arrangements, played by sixteen top Studio
musicians, look back at the swing era from
a latter -day vantage point. Especially appeal-
ing are his theme, My Buddy, Ellington's In
a Mellow Tone, and three by Cole Porter. A
stellar saxophone section of Bob Cooper,
Richie Kamuca, Bill Holman, and Bill Perkins
is shepherded by an inciting beat from drummer Mel Lewis. There are sparkling solos all
around, but the personnel listing is replaced
in the stereo by a description of the recording
method.
Because it concerns one of the first sessions held at Bill Putnam's new United
Studios in Hollywood, it holds considerable
interest, assuming he shares the views expressed by Richard Bock. After stating that
two basic recording techniques emerged out
of the chaos that was stereo recording just a
few years ago, it reveals that both are employed : "Side one uses the technique generally favored by recording engineers and
stereo 'purists.' The approach might be called
the 'all- the-way- across' technique. Here the
orchestra is presented exactly as it might be
encountered 'live' in a ballroom-the saxophone section in front, the trombones directly
behind them, and the trumpets occupying the
back row. The soloists are heard from the
positions they occupy in their respective sections.
"Side two employs the 'divided sections'
technique which, in some respects, is the most
startling of the two techniques. This presentation results in more 'ping-pong' effect
since the saxophone section is heard from the
extreme left to the center, and the brass
section is heard from slightly left of center
across to the extreme right. Both sides of this
album were recorded in the same studio using
the same mike placement. The playback perspective was achieved entirely through expert
mixing from the control booth." Something
for everyone here, and without distortion.
Ray Anthony tricks out a dozen good old
tunes i11 modern dress, augmenting his band
to twenty-five pieces to suit the occasion. Two
separate brass sections are banked on either
side -one forming a lead section with the
reeds, while the other responds with the support of Red Callender's tuba. The success of
the date pretty much depends on this lone instrument, a section in itself. It it failed to
swing, the whole unwieldy operation would
never get off the ground, despite the efforts
of drummers Lou Singer and Alvin Stroller.
Callender does a marvelous job, giving an
unusual zest to Camptown Races, American
Patrol, and Chop Sticks. The leader's trumpet
solos soar straight down the center, as do
Plas Johnson's hearty tenor-sax passages.
One of Anthony's best albums, it presents
yet another instance of divided sections. The
two basic techniques allow for endless variations, particularly when the tennis game begins. When there is intelligent cooperation
between the musical director and engineers,
a basic principle followed in these examples,
either can be handled successfully.
Freddie Gambrell: Mikado
World Pacific Stereo 1023
Shelly Manne & His Friends: Bells Are
Ringing
Contemporary Stereo 57559
By choosing a Gilbert and Sullivan operetta
for his first album of show material, Freddie
Gambrell discloses yet another aspect of his
talent. Being unsuspected, it is all the more
welcome. Nothing in his previous work indicates that he learned the score before losing
his sight more than four years ago and is
able to recall the piano part as written. When
he introduces the themes, with the help of
Paul Horn on flute, the effect is more Elizabethan than 19th Century, resulting in a
curious mixture of periods and styles. The
jazz passages are improvised in a manner
that is definitely mid -20th Century.
Since this music is now open to all comers,
the confirmed Savoyards will become more
embattled than ever. Only the staunchest defenders will find anything to complain of
here, and those who enjoy humming their own
variations will be entranced. Ben Tucker
plays bass throughout, and drummers Ray
Mosca and Armando Peraza give a Latin
lilt to Tit Willow, and I Am So Proud. Guitarist Dempsey Wright lends the correct troubadour touch to A Wandering Minstrel, I. The
piano dynamics are superb in stereo.
Shelly Manne and the Friends who started
the trend of jazz renditions of musicals are
AUDIO
56
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
the original and positive sound reproduction techniques
necessary for true high fidelity are presented on
AUDIO FIDELITY® RECORDS
the highest standard in high fidelity
UP THE MISSISSIPPI
,,.
DUXES OF
D
e
/AF/
AUDIO FIDEL ITY
STEREDDISC
Mg' fidelity
compatible
sterizphe uc
Jo
bacile,
DEMONSTRATION AND SOUND EFFECTS
his Accord an
and Orche
Keen
;tra
The romantic music of gay Vienna cap-t.red in all of its tuneful beauty by the artistry of Jo
Basile an i his accordion.
AFLP 1868 /AFSD 5868
Listen to the mellow trumpet and
wailing trombones of the latest
and most phenomenal of Dukes
of Dixieland recordings
AFLP 1892 /AFSD 5892
An informative and fascinating
demonstration cf stereophonic
reproduction including soJnds of
cannons, fire engines and sports
cars. STEREO ONLY. AFSD 5890
/,A----/DUKES
vowME ,
DIXIELAND
You HVE
Jo Basile and His accordion are
ideally suited for the rich and
graceful mcod of the sophisticated tango.
AFLP 1869 /AFSD 5869
JO BASILE
TO HOAR IT TO
SIISVS /T1
Join the phenomenal Dukes of
Dixieland as they march along
ON BOURBON STREET in true
New Orleans fashion.
AFLP 1860 /AFSD 5860
A
shining example of the remark-
able clarity and realism is heard
with the artistry of Leon Berry
at the Giant Wur itzer.
AFLP 1844 /AFSD 5844
AL MELGARD at the
and his
CHICAGO STADIUM ORGAN
VOL. 2
ACCORDEON
di ROMA
...TOY HVIE TO HlAR
IT TO
BELIEVE ITI
Twerimas
Jo Basile brings his skillful ar-
tistry to the haunting beauty of
Italian song favorites for your
listening pleasure.
AFLP 1871 /AFSD 5871
0r
The album that made dixieland
as played by the Dukes of Dixieland. You have to hear it to
believe it! AFLP 1823 /AFSD 5823
-- - - - - --
-
Complete illustrated
catalogs of the entire
Audio Fidelity library are
available from:
Audio Fidelity,
SUGGESTED PRICE
SUGGESTED PRICE
AUDIO
--
Inc.,
Dept. A - 9 ,
77011th
Ave., New York 19, N. Y.
$6.95 EACH 12 INCH STEREODISC
$5.95 EACH 12 INCH LONG PLAY
SEPTEMBER, 1959
`- - - - -bI
The brilliant highs and dynamic
lows of the theater organ are
musically displayed by the versa-
-- I- I- - - --
tile
Al
Pilelgard.
AFLP 1887 /AFSD 5887
HEAR the fabulous
1st Component Series
finest classical performances
available in stereophonic high fidelity
These re :ordings reproduce in proper
balance and spatial relationships the
musical elements as heard only
before in the concert hall.
The
®- MM'M 1- - T-
ALL ALBUMS EXCEPT AFSD 5890 ARE AVAILABLE BOTH MONOPHONICALLY AND STEREOPHONICALLY
57
at it again, it being the drummer's turn to
lead. Whether he or Andre Previn is at the
ESL Gyro /balance arm
helm, the outcome is bound to be a quick witted, swinging collaboration. Underlined by
Red Mitchell's pulsing bass, the fifth in the
series is similarly disposed. The pianist unleashes his classical training on I Met a Girl,
and a ballad, The Party's Over, is played at a
normal tempo and then reprised for a lively
finish. On Mu-Cha-Cha, Manne evolves one of
his few lengthy solos, exploring the tonal
qualities of his drums with rhythmic precision and melodic insight. The first jazz reading of Jule Styne's score will be hard to top.
especially as detailed in stereo.
I
ESL Dust Bug
Viennese Waltzes
Audio Fidelity Stereodisc AFSD5868
Ruth Welcome: At A Sidewalk Cafe
Capitol ST1209
Vienna is never far away when these i ' o
LP's are on the turntable. Jo Basile, in coatinuing his tour of European capitals, gives
the required lilt to a dozen enticing waltfes,
including Anton Karas' Third Man Theme,
Jo Basile:
A1IAVn
S1O1NO3
CONTROLS
and Cafe Mozart. Some others are as familiar
as Play Gypsy, or Strauss' Waltz Dream.
while a new experience may be in store on
the rollicking We're On Our Way To Nussdorf. The lush, romantic tones of the leader's
accordion are closely miked and centered in
stereo.
Ruth Welcome strays from the Danube city
on Non Dimeticar, Under Paris Skies, ;and
Arrivederei Roma. But the program of zither
music which avoids it entirely has yet to be
designed. She soon returns with the tidings
that The Trees Bloom Again in Prater Park.
The Milt Shaw trio, her accompaniment. is
grouped in stereo with bass and the leader's
violin on one side of the zither, while the
accordion fills out the other. The sound on
both discs has a you- are -there quality.
DISC DIRT
E
MONOPHONIC
If your stereo system often sounds unbalanced,
the fault may lie in the arm. In many cases,
proper channel balance can be achieved by
replacing your present arm with the
superlative new ESL Gyro /balance.
For balanced playback of stereo discs, the
stylus must be kept in perfect contact with the
record groove. No turntable is always level;
a conventional arm, even a tiny tilt
may result in gravitational pull which adds
pressure on one side of the groove. This
uneven pull deteriorates the sound, and
with
greatly increases wear
and styli.
on valuable records
Gyro /balanced arm can eliminate
gravitational pull caused by an unlevel
turntable, and only the ESL arm is
Gyro /balanced. Even with the turntable tilted
ninety degrees, the ESL Gyro /balance arm
keeps the stylus perfectly centered in the
groove, and the output of both channels
A
balanced!
Sonny Rollins
Leaders
&
The Contemporary
Contemporary M3564
Eddie Davis: "Jaws"
Prestige 7154
On his second visit to the Contemporary
studios, Sonny Rollins becomes a memb r of
a quintet, except on one number, You,
hen
Victor Feldman joins in on vibes. Like the
late Billie Holiday, he has the capacit to
transcend his material. But where ordi ary
popular songs were forced on the singe he
delights in searching out titles us ally
scorned for modern jazz improvisation, carrying the sheet music around in his saxophone
case until ready to amaze his auditors. This
time he uncovers hidden beauties on Billy
Hill's Chapel in the Moonlight, and tempers
with some serious moments a humorous approach to Rock -A -Bye Your Baby with a
Dixie Melody. A spare copy of Sweetheart Of
All My Dreams, anyone?
To complete the parallel, a session with
Rollins also places the other musicians on
their mettle. Did Miss Holiday's accompanists ever sound so good behind another vocalist? This is his first recording with a guitar
and Barney Kessel does his best to provk the
instrument essential. His main chance develops on a trio number, How high the :loon,
with Leroy Vinnegar on bass. The early
eight minutes of improvisation, whirl the
tape recorders caught before the start Of the
second session, may well lead to an encore.
On The Song Is You, the swift tempo allows
two rapid -fire piano choruses by Hampton
Hawes, and brisk drum exchanges from
Shelly Manne.
With due cause, critics cite Rollins as the
most important and influential tenor saxist
around. Specific instances of his influence
are rare, however. as it leads musicians to a
quiet reappraisal of their work, rather than
an imitation of his distinctive style. John
Coltrane plays under his spell and now there
are signs of it reaching out to Eddie "Lockjaw" Davis. On his current album, Davis
sounds like the connecting link between Coleman Hawkins and Rollins, cutting with emotional, if not quite historical, accuracy
across the gap which separates the two
colossi. This feat is accomplished most notably on You Stepped Out Of A Dream, Old
Devil Moon, and But Not For Me. His regular
organist, Shirley Scott, and drummer, Arthur
,
z
Join
the thousands of musicians, engineers,
and music lovers whose records sound better
and last longer with the ESL Gyro /balance
arm. Only $34.95 at your dealer's.
It's no secret that the most advanced stereo
pickup -for the Gyro /balance or any other
arm -is the world -famed ESL Gyro /jewel
electrodynamic cartridge. At only $69.95 (far
less than the cost of a comparable stereo
amplifier or pair of speaker systems), can
you really afford not to own the finest?
FOR LISTENING AT ITS BEST
Electro -Soiic
Laboratories, Inc.
Dept A 35 -54 36th Street
Long Island City 6, NY
Have you solved the problems of dust, lint,
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As dust is always present in the air,
it necessary to place fond hopes
inadequate or injurious attempts at cleaning
records, such as liquids, sprays, brushes,
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in
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turntables or record changers, gently removing
all dust and lint at the moment of playing,
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It prevents distortion caused by stylus
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stereo or mono LP record is cleaned by the
Dust Bug approximately one hundred times
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FOR LISTENING AT ITS BEST
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Dept A 35 -54 36th Street
Long Island City 6, NY
AUDIO
58
www.americanradiohistory.com
AmericanRadioHistory.Com
it settles
records as fast as it can be removed. Any
wiping of a record grinds dirt into the groove
and also increases the charge of static
electricity normally present, and attracts more
and more dust to the record.
on
SEPTEMBER, 1959
Edgehill, are augmented by George Duvivier
on bass. Stereo versions of both will be forthcoming.
Saka
Acquaye:
Gold Coast Saturday
Elektra 167
The Drums Of Africa
20th Fox 3000
An opportunity to examine the music of
Africa, both in traditional forms and their
modern extensions, is offered on these albums.
Before coming to the United States on a
scholarship from the Pennsylvania _Aeailemy
of fine Arts, Sala Acquaye represented his
native (thaun :Is hurdler at international
meets and headed a dance band. In addition
to winning prizes for sculpture here, he organized an eleven -piece African Ensemble, appearing in concert at Town Hall and elsewhere. Striking examples of the new "high
life" music, which originated in the nightclubs of Accra and spread from the capital
city to other parts of the continent, are conveyed on the calypso Coneomba, Saturday
Night, and Bus Conductor. Other numbers are
popular or serious adaptations of folk themes
or work songs. By American standards, the
rhythm section is exceptional and the drumming always attracts. Of the instrumentalists, the leader is most competent and plays
beautiful flute passages, but his mastery of
the tenor sax is less evident.
One reason given for the rise of jazz in
New Orleans is the number of military instruments abandoned in pawnshotls after the
Civil War. If UNESCO or some other cultural agency could find ways to send a few
Army surplus clarinets and trombones to the
new republic, they might help the local musicians considerably.
Recent films have displayed the colorful
ceremonial dances and tribal drumming of
The Watusi, from the Lake Kiva area of the
Belgian Congo. Their fierce challenge to the
lion, with spears beating in rhythm to feet
pounding the earth, is a dramatic experience.
Prince Omaga and Princess Manna chant love
ballads or native melodies. Notes describe the
dozen items, but fail to reveal who made the
recording. The excellent sound bears all the
ea rmarts of something a film company mode
on the scene and filed away for possible
use on a sound track. If so, more field recordin-: should be made under such auspices.
Night
Glenn Miller: For The Very First Time
RCA Victor LPM6100
\When Glenn Miller and his orchestra broadcast three nights a week on the CBS network
from 1:1 -10 to 194ì, the programs were re
corded on some 900 glass -base acetates. Although the inheritance tax appraisers regarded then as valueless, they were preserved
as part of the Miller estate. Some were reclaimed to be used in two volumes of limited
edit ion s, g, ring much satisfaction
numerous fans. Reposing on the threeto LIhis
"s
enclosed in this sumptuous folio album, complete with an appreciation by Richrad Gellman and a history of the hand, are all the
other selections worth salvaging.
To edit the material, Fred Reynolds spent
two weeks listening to playbacks, checking
off tithes duplicated in the studio and available in better form for reissue. The useable
remainder was transferred, to tapes and
Mickey Crofford went to work on the sound.
To bring it up to the broadcast quality of
the period was quite a task. The acetates
were nianufaciure for about a dozen plays
anti not meant to be stored more than a
decade. If you detect tape splices, remember
that n side often ended in the middle of a
mother and there was a slim chance of the
next side picking up at the same bar and
volinuo bevel. But where the average radio
set added distortion of its own, especially
at high volume settings, the resulting sound
on the LP's will not increase in distortion at
any level.
Miller put a great deal of thought into the
broadcasts, and Reynolds follows his format
closely. :Medleys account for many of the
fifty tiitles, and the leader is heard introducing the voices of Marion Hutton, Tex Beneke,
Ray Eberle, and The Modernaires. During
some of the pop tunes, Miller's heart is obviously on the golf course, but he returns to
form on Blues In The Night, Backlit' Chair,
t
AUDIO
SEPTEMBER, 1959
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The choice was easy...once all the facts
were in. First, he learned that Bogen
has the experience. That's because Bogen
has a larger engineering staff...has
made more sound equipment than any
other hi -fi manufacturer.
Next, he compared prices. Found out
he'd have to pay as much as $50 more
for components with power, sensitivity
and versatility to compare with Bogen's.
Then he listened. Incomparable!
Finally, the most exacting test of all...
his wife's opinion. Not only did wife like
Bogen's clean styling, she was amazed to
discover how easy it is to use the complete, yet uncomplicated controls.
That did it. Our friend took the DB230A
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59
Memphis Blues, and Solitude. The set will
wear best at a dancing party and there is
nostalgia aplenty for his countless followers.
Herbert Pilhofer: Music With The Modern
Audiophile AP61
Touch
In order to circumvent any association
with progressive jazz, apparently believing
the words to be incompatible, E. D. Nunn
exercise his perogative as company head
and avoids mentioning jazz at all on this
album liner. Although preferring to note that
the interpretations "suggest the European
touch," he must hold a grudging admiration
for Herbert Pilhofer's work in order to record
it so well. The young German pianist came
to this country in 1954, settling at the University of Minnesota where he is a staff
member. His group makes a Minneapolis
night club its headquarters and appears in
concert each summer at the Walker Art Center. The present nucleus is a trio, boasting
an exceptional bassist in Stuart Anderson,
and a guitarist, Dale Olinger, who for sensitivity can only be compared to Charlie Byrd.
Besides playing melodic improvised passages,
he varies conventional rhythms by a drumlike
beat ticked off on muted strings and striking
unison effects with bass or piano. It is most
effective on Don Specht's Monk' Cloth. Seven
selections range from a Werner Heider canon,
to Duke Jordan's Jordu, and Thelonious
Monk's Round About Midnight.
When arranging for a nonet, the leader
explores the possibilities of instrumentation
even further, also playing celesta. There is
fertile interplay between David Karr, flute,
and Robert Crea, bass clarinet, on l'as Beginning To ,Sec The Light. Jack Coan. trumpet,
has a fine open solo on You're My Thrill. Paul
Binstock, French horn, and Stanley Haugesag, trombone, blend well and add to the
depth of sound, as does the placement of
Robert Pope's drums. The influence of Monk,
everywhere present to some degree, re'urns
on Bemsha Swing. The composer should hear
this treatment before his next Town Hall
concert. Some of Pilhofer's ideas would fail
to swing without considerable rehearsal, but
his group smoothed out any uncertainties before recording. They blow a fresh breeze
through their chosen area of modern music,
call it what you will, and the recorded sound
is bright and dynamic. Should Pilhofer write
a concert piece for Doc Evans' cornet, perhaps his engineer will be won over completely.
A Concert With Hillel And Aviva
Elektra 171
The Tarriers: Hard
Travelin'
United Artists UAL4033
singers are fortunate in their ability
to resist pressures that would force them
into rigid molds. Perhaps they are aware
of what happens when a small but influential
clique persuades a jazz artist to discard the
elements which make him an entertainer. The
performers engaged on these albums, at least,
are venturesome in choosing material and use
it with originality and wit. Recorded in concert at New York's Town Hall last March,
Hillel and Aviva combine the old and the new
in a stimulating mixture. As most of the
fourteen songs are from Israel, they are accustomed to a music that is vital and growing, yet steeped in tradition. On turning to
English. they are well equipped to bring a
youthful freshness to the ancient tale of
Joshua's providential victory at Jericho. And
an account of a poultry farmer's solution to
his troubles, one of the funniest songs ever
recorded, causes the audience to roar with
laughter. They accompany themselves with
Hillel's shepherd's pipe and Aviva's Miriam
drum. supported by Anatoly Malukoff, guitar,
and Bracha on drums.
The Tarriers never hesitate to refashion
a song to fit the special needs of the group
and are determined to get the most out of
each one. A lively enthusiasm leaves little
room for anything static in their concept,
and the dozen arrangements used here may
FFolk
sound different the next time out. Erik Darling, who turns up at many such fests, is on
banjo, while Bob Carey and Clarence Cooper
play guitar. Besides the harder side of life,
they consider Love Oh Love, Darlin', and
Hush Little Baby. Bassist Chet Amsterdam
and drummer Charlie Persip are in attendance.
Stuff Smith: Sweet Swingin' Stuff
20th Fox 3008
Florika Sava: The Mad Gypsy
Capitol T10139
Ever wondered about the violinists who
used to prepare silent movie stars for emotional scenes? Well. here are two who can
do the job without half trying. Always unpredictable, Stuff Smith stretches his flair
for the unexpected over into the domain of
mood music. Words are superfluous when he
describes the pathos of A Bird in a Gilded
Cage, Hearts and Flowers, and 0 Promise
Me. Now that smellovision is in the wind,
perhaps this label's parent company is getting ready to pull a switch and try a film
without spoken dialogue. His voice is irrepressible, however, and gives needed spice
to the bland material. John Letman's muted
trumpet adds a dash of pepper, and the
rhythm section of Jimmy Jones, George Duvivier and Denzil Best is well seasoned. When
Smith had a stand opposite Louis Prima on
52nd Street, his was the noisier side. After
this, Prima may respond with lullabies.
Florika Sava departed his native Rumania
for Istanbul in 1940, moving on to Buenos
Aires after the war. There he combined
the sweep of the pampas with his already
fiery melodies, making him easily the wildest
of the gypsy fiddlers. Both lie and Smith,
when most daring, are willing to try the
seemingly impossible and, more often than
not, achieve it. He leads his ensemble on a
dozen tunes, ninny traditional Romany airs,
while others are as current as To Zsa Zsa.
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AUDIO
60
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(Audiophile Net, Zone
I).
SEPTEMBER, 1959
STEREO MULTIPLEXING AND MATRIXING
variety of recorded material, that should
have proved their proponent's contentions applicable to any kind of program
technique. But there is at least an equal
variety of loudspeaker types, methods of
arrangement, and types of listening
room. How many have also conducted
extensive tests in this area?
Probably millions of people, on single
channel hi -fi, could not tell the difference
when frequencies above S000 cps (or
even 6000 cps!) are removed or left in.
But there are also many discerning enthusiasts who would immediately notice
this difference. It is largely a matter of
listening education. But because of these
differences, various test groups would
lead to varying results and conclusions.
There are many contributing reasons
why all the tests quoted may be quite
truthful against their sera, often unstated, terms of reference, and yet apparently contradict other equally truthful results, because neither presents the
whole story.
Prospects
There is a sense of urgency about the
whole thing. The high fidelity industry
wants to get stereo "on the road" and
right now radio is a "hole." or weak
spot. Availability of radio as a stereo
source would help sell stereo as an entity
to the public. The FM operators and
(from paye 30)
multiplex manufacturers want to see a
decision because meanwhile everyone is
waiting to see "which way the cat
jumps."
However, the fact is that there is as
yet insufficient evidence on which to base
a decision, in either area. The FCC needs
answers as to the practicability of putting however many channels on one
carrier they may ultimately decide to allow. Radio is still a public medium, and
all interests must be properly protected.
As yet there is insufficient data.
Just what stress will go to the importance of maintaining potential fidelity of
future stereo transmission remains to be
seen. But I feel that stereo is only just
beginning, and that efforts so far will be
judged as crude by tomorrow's standards. Not only will it he possible to transcribe better fidelity on two channels,
but new techniques will emerge, enabling
the two channels to contribute to an overall result with much better precision. In
consequence, differences which are today
observed as indistinguishable may become important tomorrow.
So I cannot advocate the built -in quality limitation of Calbest, which may not
be discernable today, but may become
very important tomorrow. The intentional quality difference of the original
Halstead system has already been aban-
doned, so I need say no more about it.
Both the Burden and Bell systems (if
the latter should he so applied) are
methods of maintaining compatibility
with a system (A \[ /FM) where quality
was inherently different anyhow. This
may aid the transition, but I also feel
there is a danger that commitment to
such a system as standard will restrict
the possible future of stereo.
Work in other areas, both with recording media and speaker development, suggests the stereo of the future may utilize
channels that are basically "mono" and
stereo," rather than "left" and '`right."
From this viewpoint, I cannot help feeling that the Crosby system is compatible
with the "stereo of the future."
But, much as many would like to see
an early decision, I do not think we can
expect one, nor would it be good to have
on, in the long, run. The analogy with
the decision on color T V is often mentioned, from various angles. Maybe it's a
good one too, if we don't try to apply it
in detail at the time, the decision seemed
long in coming; but how far has color
TV progressed .'ace:' [t can hardly
claim widespread acccptanee. The FCC
should not be pressured into an early
decision, but will, we hope, wait until
sufficient facts are available for a clear cut decision.
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AUDIO
SEPTEMBER, 1959
61
AUDIO ETC.
(from page 11)
ting the record onto the changing post and
pushing the start button, is seldom an out -
and -out pleasure. Just a nuisance, and the
wait for the cycle to complete itself and
the music to start can seem exasperatingly
long-especially when the arm returns
placidly to its rest position, instead of
settling onto the record, or whips into the
ten -inch or seven -inch location. It shouldn't
do these things but somehow, it often does.
Nevertheless, the automatic start, when
it works, insures a clean beginning and an
undamaged groove and pickup. What we
need, I think, is a simpler one, much faster
working, minus the fancy cycling motions
of the full -scale changer. Push the button
and the music should begin, say, within
three or four seconds. That would do it.
With such an automatic starter and with
the standard, time -proved automatic stop,
a manual record player really has 99 per
cent of the advantages of a changer. No
wonder the changer manufacturers now like
to boast of their changers as manual
players too.
Dual 1006
The Dual 1006, which I've been using on
and off for the last month or so, is a good
example, as they say, of recent trends. This
changer is Kerman and shares some of the
conventions usual in that country with the
long -familiar Miracord line-the same pushbutton controls, including STOP, START and
that cryptically spelled REPET which
might be either had English or good German, for all I know. (Art 'wily the abbre-
-
riation for REPETilirr (peration. ED.)
There's the same pair of removeable spin dies, a long one for changing and a short
one for "manual" operation; the Dual and
Miracord also share the absence of overhead arms or platforms -the records are
supported for changing entirely by the
spindle's small protuberances.
center
Clearly, both of these machines come from
a common tradition of changer thinking.
Refinements in changers are now to be
classed as small and large. Small refinements are involved in such crucial matters
as arm mass and freedom of movement,
rumble and the like in motors, smoothness
of the whole drive mechanism, gentleness in
the treatment of the stylus and the record.
I say "small" because refinements in these
areas are physically on a delicate plane,
often quite invisible to the eye.
These smaller refinements are by far the
most important, given stereo and our new
standards for stylus force and all the rest;
but they don't show up very dramatically
on casual trial -they are negative in effect.
If the machine works; if it changes, plays,
is reasonably rumble -free (and especially,
if the rumble ratio between mono, or lateral -only, playing and stereo, or lateral vertical, playing is acceptable), if it skips
no grooves, leaves records and stylus undamaged. drops, lifts, turns on and turns
off correctly and in the right place at the
right time, in spite of featherwight arm
and feather -free bearings, then the machine
benefits from optimum "small" improvement. Lack of these minute but crucial
adjustments in design makes many an older
changer useless for today's stereo, even
with four -wire stereo harness, new cartridge
and every- modernization you can think of.
By "large" refinements I mean those
dramatic new methods of operation that
really make a changer look and act new,
right. off. They are good for sales, ami
usually useful as well, though the small
things are really far more important. The
GS 77 changer, for example, stops its table
dead during the entire change cycle, picking up speed after the stylus is lowered to
the record; the cycle itself is fixed in speed,
independent of the four playing speeds.
Two good ideas, both on a relatively large
scale -call them macro -improvements. The
Dual changer has comparable features,
though somewhat different in detail.
Dual's change cycle is also independent
of playing speed, but the table keeps turning -not, however, at the speed setting indicated by the records you are playing. As
the change cycle begins the table suddenly
lets go and turns at 45 rpm. On LP and 16
it speeds up; at 78 it slows down. This is
an odd thing to watch-and, indeed, the
Dual's actions are startling to the eye in
a number of interesting ways. Looks as if
the table had suddenly gone out of control,
as it speeds up and begins churning around
wildly, while the record drops! But the system works beautifully the proper speed is
resumed in plenty of time for the music to
begin (if it didn't there'd be some dreadful
sounds!) and all is just dandy.
Reminds me of my first LP -speed changers, which changed so slowly (having been
geared for the old 78's -that in exasperation I used to throw the speed switch up to
78 to hurry things up. Dual (lees it for you,
automatically.
But the most startling thing about the
Dual changer is the unique "feeler" mechanism, which tells the stylus where to drop
for any size record, standard and all sizes
in between. It presents the most amazing
psychological hazards, purely visual, that
I have yet encountered -but it works, and
has been working entirely satisfactorily for
me to date without the slighest damage to
records and stylus.
The psychological hazard is in the extraordinary arm motions that takes place
;
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62
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AmericanRadioHistory.Com
SEPTEMBER, 1959
when this machine goes into its change
cycle. The first time I saw them, I couldn't
believe my eyes. Here's what you seem to
see:
Push the START button and the arm lifts
off its rest, swings quickly out over the
inner record grooves and proceeds to drop
all the way down onto the disc with a
thump -then it drags itself straight across
the entire surface sidewise, out to the edge,
where it proceeds to fall off. Your eyes are
quite right
does ride on the record
grooves. If you are able to watch this far
without flinching, you'll then see the arm
rise up nonchalantly once again, move serenely over to the first groove and lower
itself piously and gently at the correct
spot, meek as a limb. Crazy.
The first time I saw this, unforewarned,
I grabbed the arm off the record and
swore! (inc disc ruined, I thought. But
what actually happens, what really goes on,
is an ingenious new device that is more
practical than it sounds. The arm doesn't
scrape the stylus over the record at all;
instead, there is a tiny wheel, canted a
bit, which rides lightly over the tops of
the grooves and steers the arm back to the
edge. where it falls off -onto another,
which sends in a figurative message to the
changer's mechanical brain, saying, here is
the spot where the arm must come down.
It is the spot too -without fail. Can't go
wrong, no matter what the size, unless
maybe you have an elliptical record to play.
Once all this is taken care of, things
retract and when the arm comes down the
next Iinu, rightly- positioned, the stylus is
finally exposed, to play the grooves.
I adanit it sounds zany, but I can't really
find anything too seriously wrong with the
system, once you get used to the psychological hazards involved in watching it.
Remember that this system operates with
-it
an extremely light arm, designed to track
at from 2 to 4 grams or so. The small wheel
does not " scrape" the record surface; it
rolls on it; and I have so far been unable
to find any trace of a mark where it passed.
The "fall -off" principle is infallible, since
it measures every record impartially for
size without preconceived notions, and this
is clearly a good idea, other things being
satisfactory.
I do have two suggestions, though. First,
in my Dual, the arm definitely drops too
suddenly onto the record surface and onto
the small wheel
bounces, and oscillates
as it rides back towards the edge. No harm
done, but a more gentle descent- easily
it
managed, I think -would add a safety margin and make for better visual appearnacc.
I hear rumors that this has already be_n
taken care of in later production.
The other suggestion is simply that there
is an inherent difficulty here worth a
thought, well understood by the makers
and amply provided for, but still a difficulty. The small wheels on the arm require
the stylus to be placed with extreme aee-uracy, within a very small vertical tolerance, If it extends a fraction of a millimeter too far down, there will in truth be
a catastrophic squawk when it gets dragged
over the record!
Once correctly mounted, there is absolutely no way in which further trouble can
occur, and the Dual's designers have provided all that is needed to get things right
the first time. Nevertheless, caution is advised, and you will find that one or two
cartridge models cannot be used at all in
the Dual, as now manufactured. My Pickering fits to a T and works to perfection.
What else, The Dual is absolutely silent
in use; the motor is so quiet you must put
your ear to the table to hear it. Rumble
and pitch steadiness are absent and ex-
cellent, respectively-very good for a
changer. The machine is small, compact,
without fancy arms and legs and extensions; with the smaller spindle in place it
looks altogether like a manual playernothing protrudes higher than a couple of
inches. Good. There is automatic retracting
of the drive and, for double safety, a neutral position on the speed shift. (Indeed,
once in awhile my Dual goes into neutral
at the beginning of a record when it ought
to be playing. That's efficiency for you.)
Manual Playing
The best features of the Dual, for my
listening, are its excellent "manual- play"
facilities, which are more serviceably
"manual," more flexibly 'automatic" than
any changer I've tried before. It will do
more things that please me, plays fewer
nasty tricks on me, than any "changer" so
far. (Excuse the quotes -it's getting so
that one can't be sure when a changer is a
"changer," and that is all to the good.)
The Dual, in its alternative "manual"
operation (with short spindle inserted)
gives you a sensible and useful choice at
all times between semi- automatic and
strictly manual operation. You can do it
either way, without adjustments. To start
it you may press the regular START button
and the machine goes through its usual
cycle (as above) and plays the record. Or
you may lift the arm manually by its
"wing" lift (not far enough from the record surface for fat fingers to get hold of,
but OK for my- medium -gauge ones), flip
a little white slider marked MANUAL and
the record turns. Replace the arm on its
rest by hand at any point and the table
stops, via one of those nricroswitehes
mounted in the arm rest. Entirely manual,
you see.
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This turntable incorporates every valid, time -proven design principle: belt
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Your dealer is listed in the Yellow Pages. Or write for complete information.
SPECIFICATIONS
SIZE: 153/4" wide,
te,
RA -498
Tone Arm
WOW: 0.14% rms.
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FLUTTER:
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RUMBLE:
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COLOR: Morocco red with aluminum trim.
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GENERAL DYNAMICS
A
1
OF
4
1
8
N. GOODMAN STREET
SEPTEMBER, 1959
Tuner
kc.
available.
"There is nothing finer than
AUDIO
"e:=2"
00
0
o
a 0
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ASR -444
0 0
0 0
O
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"Stereo 60"
Amplifier
ROCHESTER 3, NEW YORK
63
The best thing is that you can put the
arm down in any grove right up to the final
one and the music will play -the automatic
trip does not snatch the arm rudely out of
your hands, as in so many changers in the
past. This has long been one of my pet
changer beefs. Now, enfin, I am satisfied.
Yep, the trip does work, when the stylus
reaches the lead -out grooves, eccentric or
non- eccentric. The arm then -and
ly
then-returns to its rest position. ow
that's what I call real manual automat on.
You can use the automatic STOP bu ton
alternatively, if you want, to shut Ithe
thing off in the middle of a record. The
cycling goes through in its usual f rm
(with a few more of those visually dd
spasmodic heavings that are typic lly
Dual, as though the arm couldn't mak up
its mind; it does of course -the e ect
again is purely visual). Or you may ust
lift the arm off the record and set it oqq its
rest. Either way works, and the machine
doesn't mind a bit which way you do it.
Even the REPET button can be used; push
it down and at the end of the record the
cycle will begin the same side again, automatically. (The REPET cancels if you push
one of the other buttons.)
There you have it. Uh, Oh yes . . . I
forgot a couple of dozen details, like, for
instance, that this is a stereo changer, complete with a four-wire system (how could
I forget that ...) the cartridge holder lets
the cartridge out with a quarter -turn of a
little top lever-very neat -and there is a
mono- stereo switch (paralleling the two
sides of the cartridge for mono playing)
that is not placed underneath the turning
record, but out in a good spot at the arm
pivot, marked with a single circle for mono
and two linked circles for stereo. (You
have to use your imagination on that.)
Ah yes
there's a built -in stylus force
gauge, too, a little red hook next to the arm
rest that operates a pointer on a dial below.
Does it read correctly? I wouldn't know; I
didn't bother to try. (But you'd better.)
I'm getting so my finger, lifting the stylus
by its point, is a fairly good indicator of
proper stylus force, or weight, anyhow.
(Not pressure; the styli don't usually stick
out far enough to hurt your finger in proportion to actual point pressure and, any. a
how, my skin is too tough.) Still
stylus force gauge right at the spot where
it reads
it counts is a very good idea
Æ
right.
...
-if
TAPE GUIDE
(from page
within the tape machine. In one position of the A -B switch, the tuner signal
is routed to the control amplifier ; in the
other position, the playback signal from
the tape machine is fed to the control
amplifier.
Figure 11 shows a hybrid arrangement. The playback signal from the tape
machine may be fed to the control amplifier in the same manner as other high level signals, if desired. Then the signal
enters the amplifier at an early stage and
is subject to the frequency- shaping controls, which is desirable when playing a
previously recorded tape. On the other
hand, if one is in the process of recording, say, the tuner signal onto tape
and wishes to hear the tape playback
signal for comparison with the tuner
signal, it would be necessary to set the
play-monitor switch to the tape position; this introduces the tape playback
signal at a late stage, after the uner
signal has been fed to the tape recoder.
Summary
The foregoing discussion has indicated that the control amplifiers and integrated amplifiers on the market employ
various means of feeding a signal to the
tape machine and of accepting a signal
from the machine. Also, the tape ma-
.38)
chines vary in their signal switching facilities. Therefore, when incorporating a
tape machine into an audio system, it is
necessary to take into consideration the
characteristics of both in order to be
certain that the two are compatible with
each other and satisfy the needs of the
owner. Otherwise it may happen that the
operator finds himself having to connect
and disconnect cables every time he
switches between the recording and playback modes.
Physical Installation
Most tape machines in home use are
designed to be portable. In the process
of installing a tape machine in the audio
system it may be wise to do so in a manner that facilitiates removal of the unit
from its normal location in case it is desired to record or play back at other
sites.
Whether or not portability is a consideration, the tape machine should be
readily accessible for servicing and ad-
justment. Proper maintenance requires
getting into the transport mechanism
periodically to clean and lubricate parts,
as well as to make minor adjustments. If
the unit is "buried" in a cabinet in a way
that makes access arduous, maintenance
is likely to be neglected.
TAPE -MONITOR
SWITCH
TAPE
-o
OUTPUT
MONITOR
o
TAPE AMPLIFIER
INPUT
signal from a tape machine.
Fig. 11. Hybrid arrangement for accepting the playback
AUDIO
64
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
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Less than 1% total R.M.S. Harmonic distortion at 400 cps.
Hum Level -59 db on phono and tape head inputs; -79 db
on tuner input. Controls individual bass and treble controls
for each channel balance control and phasing switch single
volume control adjusts both channels simultaneously separate loudness control AC accessory outlet. Inputs Tuner,
Stereo Phono, Stereo Tape Head. Outputs : 4/8/16 ohms
and Tape Recorder. 117 VAC, 50/60 cycles. Size: 12" W
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CLIP
III
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65
EDWARD TATNALL CANBY
Summer is a parlous time in the record
reviewing world. In audio itself, nobody's at home in summer -everybody
and his brother are on vacation and unavailable, just when you (I) want desperately to get the latest gossip for the big
fall issues of our magazine.
In records its the other way 'round. I'm
the one who has to get a bit of a vacation
from listening -and right, plumb in the
middle of it, out come all the fall records,
by the hundreds, not to mention most of
the Xmas Specials, wreathed in holly. Ugh.
Thus I'm admittedly a bit behind, this
month; the following are mostly chosen
from the huge piles of interesting material
that were on hand for me to sample before
the fall rush even began. No great matter
they're still fine records, and by next
month I will have ploughed through the
huge new pile of autumn releases, including a whopping batch of Telefunken stereos
at $2.98, via London. Better look at those
soon; I'll be in the midst of them next
month, to help you. E. T. C.
-
1. SPECIALTIES
Brahms: Piano Sonata in F, Op. 5, Intermezzi, Op. 117. Geza Anda.
Angel 35626.
an interesting
was
Brahms
The young
character, not nearly well enough known today in contrast to the crotchety old man with
the beard, Brahms in his late years. The
youngster, aged 20 or so, was blond of hair
and beardless with blue eyes and a strong
face; he was an earnest modernist of that
day, the early 1850's -which meant that he
wrote loud, sincere, brash, impressively Romantic music that made his piano shout and
roar. Schumann immediately spotted him as a
coining genius, raved over his music, called it
"veiled symphonies" ; in short order, Brahms
was writing in a Schumann style, but more
extrovert, headier, stronger.
The third of these early sonatas, part of it
written after the meeting with Schumann,
Anda plays here with remarkably sound styling. This is a big, solemn, grand performance
of music that surely seemed big, solemn, and
grand to Brahms himself, the young stalwart.
It should sound that way, even though its content is often windy, its expression youthfully
overblown. No use apologizing for it, as some
do in the playing ; no use modernizing it
into a furious frenzy, as others do, trying
hard to make more of the music than is in
its nature. The best thing is to play it as
young Brahms must have felt it, his newest,
most advanced, biggest piano work to date.
Anda seems to be a natural Brahms player
-which is mighty unusual these days. Some
of his earlier recording of other composers
seemed to me hard and unmusical ; the only
possible criticism here, on the score of musicianship, is a certain blurring with the pedal
that occasonally smears the harmonies.
*
780 Greenwich St., New York 14, N. Y.
The three wise, restrained Intermezzi, from
the end of Brahms' life, are played with equal
perception and style-they seldom sound better. Late Brahms fares as well as early.
The recording is technically one of the finest
examples of piano sound I've heard, big, natural, unforced and well balanced with sharp,
clean transients and fine bass, clear treble.
It's an excellent demonstration disc.
Shostakovitch: Piano Concerto #2. Ravel:
Piano Concerto in G. Leonard Bernstein,
N. Y. Philharmonic.
Columbia MS 6043 stereo
This seems to me very much Bernstein's
different ways.
meat, both sides of the disc
He plays and conducts both works.
his lighter,
of
one
is
The Shostakovitch
brassier pieces of recent days (1957) in which
Bernstein's best dry -style pianism comes nicely
to the fore. Shostakovitch is not personally at
all like Bernstein, but his musical expression
is within that modern, slightly dry, almost
classically wry sort of restraint that is Bern stein's best natural expression -even in his
popular music. I enjoyed the Shostakovitch no
end here, whereas some of the more bloated
pieces for orchestra alone I find pretty heavy
going.
As for Ravel, the exquisitely expressive G
major piano concerto, actually his second
(the other is for left hand alone and so doesn't
quite rank), is out of Ravel's American Gershwin period, yet it is also full of the familiar
Ravel old -world elegance, of the "Mother
Goose" suite, the "Pavane for a Dead Princess"
-in
and the like.
Ravel was always a curious and explosive
mixture of sensitively felt opposites, of violence and good breeding, elegance and hysteria.
He was enormously impressed both by America
and by Gershwin and if you'll listen, you'll
spot Gershwin everywhere in this music. Bernstein is a natural to express the bitter -sweet,
almost enviously beautiful Ravel "jazz " -so
elegant, yet so explosive, too. Ravel envied
Gershwin's untutored freedom and directness,
as Gershwin admired Ravel's incompaable,
incredibly polished technique ; neither ould
match the other, both recognized the priceless
values in the other's work.
All this is wonderfully evident in the first
and last movements of the Concerto, ' vhich
Berstein plays in his most effectively jazzy
classical style -just the right combinati¢n for
him. But something goes wrong in the ellegant,
wistful slow movement with its Ion and
faintly blues -like tune for the piano. It Should
pulse steadily and evenly ; Bernstein su denly
goes off on one of his (to my mind) u ortunate Romantic jags -he plays this meld y like
so much Chopin, full of rubato -slo ingsdown, unevenness-and I find it dismalli false
in effect, inconsistent with the rest of tie interpretation.
But the outer movements, the fast ones, are
unbeatable. Every other performance that I
can remember treats these movements in
purely European fashion without so much as a
thought, as strictly "classical" music' only
Bernstein understands the deeper Gershwin
implications and gives the music the greater
dignity and elegance it gains through the expression of its American feeling. I say he's
tops.
Stravinsky: Agon (ballet). Berg: Three
Pieces for Orch. Op. 6. Webern: Six Pieces
for Orch. Op. 6. Sudwestdeutsches Orchester, Rosbaud.
Westminster XWN 18807
As you may possibly have heard, old Stravinsky has taken over the "twelve- tone" technique for his own, lately (though, needless to
say, in his own special way) ; here he is in
one of the notable works of this new Stravinsky period, right along with the music of
two of the original early twelve-tone men,
main disciples of Schonberg himself. An interesting trio of works and though I don't
pretend to be able to "explain" any one of
them in orthodox twelve -tone theory, I still
have ears and so have you ; the music will
interest you and no doubt about it.
Webern, the miniaturist, is the toughest of
the early twelve-tone boys for us adults. But
it is astonishing to discover that today, un-
tutored teenagers with normal musical ears
find him very much to their liking. I saw it
happening recently. Six short sections, each
a highly skilled patterning of abstract soundbuilding blocks, good for hi-fi as well as the
musical -mathematical mind. Alban Berg, the
incurable late- Romanticist among the early
Twelve -toners, is noticeably more expressive
in the old- fashioned manner -you'll find him
the easiest, most likely.
As for Agon, it's a ballet, a "competition"
among twelve dancers (not representing the
12 tones of the scale !) and though entirely
abstract and plotless is a superbly integrated
musical -ballet whole, quite easy to watch and
hear simultaneously, as I found out recently
at a New York peeformance. Farts of it are
highly humorous, in a severe, Stravinskian
way. It's dry in sound but fascinating in both
rhythm and tone color and you won't need to
think twice about the twelve -tone aspect. It
tells its own story in musical terms, as all
good music should do, I think.
A nice record for aural experimenting, if
you're interested.
Rosetti: Concerto in E Flat for Two Horns.
Dittersdorf: Concerto in D for Double Bass
and Viola. Soloists, Copenhagen Sym-
phony, Jenkins.
Hayden Society HS 9052
Jenkins' characteristically bright,
nervous style of conducting, in the resurrected
works of the eighteenth century that are his
specialty, carries over into this disc out of
Denmark -he has conducted Italian and German orchestras and has his own American
group in New York who give the annual Clarion Concerts. This record is a product of the
newly resurrected Haydn Society, which has
as many lives as a kitty cat. Don't know how
many times it has been pronounced dead in the
past-but it is definitely alive now, or was
when this disc came forth.
(Continued on page 81)
Newell
AUDIO
66
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
from III4nTtosh...
PERFECTION
INPUT SELEC'OR
Pl101q
S
TUNER
2
RECORD COMPENSATOR
SASS
BASS
TREBLE
0
0
Control
TREBLE
1
M
400
M
TAPE
-10
RIAA
-S
PMONO2
2
1
AU S
in Stereo
TAPE
TAPE
-12
RIM
LP
1
2
TAPE MD
Industrial design by George
H. Kress Associates.
$225 less cabinet
Simplicity, flexibility, and beauty have been integrated by careful engineering
and design in the McIntosh C -20 Stereo Compensator. The greatest listening pleasure in stereo or monophonic reproduction
is
assured as a result
of over a year of careful and diligent research in the requirements of a new
preamplifier designed for stereo. Full stereo flexibility has been provided plus
built in protection for your investment in monophonic records. McIntosh has
designed in the C -20 Stereo Compensator the necessary features required to give
the finest monophonic reproduction the keenest listener may require.
Complete satisfaction is yours in monophonic and stereophonic with the McIntosh
C -20 Stereo Compensator.
Iligniosh***-de
ikr"'w
FACILITIES
Mode Selector:
SPECIFICATIONS
positions including Stereo, Stereo
Reverse, Left channel on left speaker
only, Right channel on right speaker
only. Left channel on both speakers,
or Right channel on both speakers.
Monophonic:
Internally parallels and decouples a
stereo phono cartridge to offer best
quality reproduction from monophonic records.
Tone Controls:
Treble: boost 13 db at 20 KC
attenuate 18 db at 20 KC
Bass: boost 16 db at 20 cycles
attenuate 20 db at 20 cycles
Trim Controls:
Separate channel back panel controls to balance the frequency response of the system independent of
front panel controls.
Equalization:
Separate bass and treble 6 position
switches, including NAB tape and
flat for any low level flat source.
Aural Compensator: Fletcher -Munsen compensation, continuously variable.
Rumble Filter:
Rolloff to reject low frequency disturbances such as rumble.
High Frequency
Two positions, 9 KC and 5 KC to
Cutoff:
suppress hiss and noise.
Phase:
180° phase reversal to phase speakers or source material.
Balance:
Attenuates alternate sides of center
40 db each channel to balance for
unequal source material.
Tape:
Front panel jacks, push button
controlled, to permit the use of a
portable tape recorder without disrupting permanently installed equipment.
Tape Monitor:
To permit instantaneous monitoring
of tape while recording.
6
BASS COMPENSATION
TREBLE
CO
Power Requirements: .1
Input Sensitivity
and Impedance:
17
VAC; 35 watts
Auxiliary, Tape, and 2 Tuner 0.25 V
at 470K
2 Phono, Low: 2.5 MV at 47K
High: 12.5 MV at 47K
XTal: 0.1 V, very high
2 Tape Head, Low: 1.25 MV at 47K
High: 6.25 MV at 270K
Tape Monitor: 0.25 V at 130K
Frequency Response: +0.5 db 20 to 20,000 cycles
Distortion:
Less than 0.2% at rated output, 20
to 20,000 cycles
Hum and Noise:
High level inputs: 85 db below rated
output
Low level inputs: less than 2 microvolts at input terminals ( -115 dbm)
Outputs:
Main: 2.5 V with rated input
Tape: 0.25 V with rated input
Gain:
Low level inputs: 1000 -1 Main Out-
put
Low level inputs: 100 -1 Tape Out-
put
High level inputs:
put
High level inputs:
put
10 -1
Main Out-
-1
Tape Out-
1
A.C. Aux. Outlets:
unswitched for tape machine or
turntable and 3 switched
Size:
Chassis:
Weight:
17
1
14%2 inches wide; 41/4 inches
high; 12 inches deep
Front panel: 143/4 inches wide; 41/4
inches high
pounds
SAWN
AURAL
COMPENSATOR
NAM
100
10
_L
too
200
BASS
SOO
INC
INC
TONE CONTROLS
TRIM CONTROLS
TREBLE
20
McIntosh
LABORATORY INC., 4 Chambers St., Binghamton, N. Y.
IN CANADA: MANUFA..CTURED BY McCURDY RADIA INDUSTRIES, LTD.; 22 FRONT STREET WEST, TORONTO
www.americanradiohistory.com
AmericanRadioHistory.Com
PRODUCT PREVIEW
A continuation of last month's "look into the future," covering
phono pickups and arms, microphones, and a few miscellaneous items.
AFTER LAST MONTH'S ATTEMPT
to inthe products of all the
manufacturer's in the high fidelity
industry, we learned that there was con siderably More than we expected that
needed to he covered, and we did at least
indicate that there would be more material to follow in the succeeding issue
on the subject of phonograph pickups
and arms, and on microphones. In addition, there were a few manufacturers
whose products were not covered at all,
either because of space limitations or
because their material had either been
mislaid or had not arrived in time to be
included.
Even after this issue it is likely that
there will be some products that are considered of great importance to the individual manufacturers but which did not
seem to our editors to be of sufficiently
great importance to he included. And,
regrettably, when it comes to the final
allocation of space it is these saute editors who must be responsible for the decisions as to what goes in and what
doesn't. Of one thing we are sure -we
have made a valiant attempt to include
all the material available. If not every
product of every manufacturer is not
represented in these two sections, it may
be that we did not have the information,
or that we have had to try to Make a
fair space allocation. Naturally a manufacturer who makes two hundred different products can not expect to have two
hundred times as much space as the
manufacturer of only one product. We
only hope we have selected products that
interest our readers as touch as they
interested us, and that the information contained herein will be of some
reference value throughout the year.
As we said last month, this is a catalog- type presentation and it must he remembered that the statements made
about the various products described
are not the resoIts of our own testing,
but are the specifications as furnished
by the manufacturer with occasional observations of nun own. Actually, in the
case of phonograph pickups, we have
personally tested most of the models
described, but naturally we cannot indicate any preference. Phonograph cartridges are in a smnewhat similar category as loudspeakers -not all of them
sound the same, and what one listener
likes another may not. We have this to
say, however -given a blindfold listening test on an A- 13- C -D -E -F -rte. basis,
clude all
AUDIO
Of
SEPTEMBER, 1959
we do not believe we could say which
pickup was best; one might be described
as being harsh, possibly due to a peak
in the upper-high -frequency range; another might he described as being extremely smooth; another mellow, and so
on. Naturally, any product which is expected to compete with all the others on
the market must be assumed to have
some good qualities. Perhaps one pickup
has more hum than another, yet in a
proper installation the hum is of no
problem and its user will swear by it.
Another pickup may have an exceptionally extended high -frequency range,
which could sound good on a system
inclined to he dull whereas the shine
pickup might sound harsh on a system
which in itself was inclined to be too
bright. If all systems were exactly alike
it is possible that every experienced
listener would choose the saune pickup.
Since all systems are far from alike, it
is probable that their owners would
choose pickups which were complementary to the over -all system with the result that they would begin to sound
similar. This is somewhat akin to the
well -known "Hi -Fi Show Response
Curve," which is a common term for an
over-boosted bass and treble. Given a
system with "perfect" reproduction, it
is likely that the average show -goer
would walk past without even a look -in.
But with really flamboyant reproduction
-with over -stressed highs ( "Oh boy,
listen to them triangles!) and super boosted lows ( "Listen to that cat on the
doghouse! ") people are sufficiently impressed to came in and listen. Not that
they would continue that type of reproduction in their own homes for more
t!.au a month after they got the equipment installed -but at least they come
in and listen.
Who's to say what is right? One listener may like the sound equivalent to
what he hears from the top seats in the
Ilollywood Bowl while another may
want to sit in the second row at Carnegie IIall. And if that's the way the
listener wants to hear music, why
shouldn't he make it sound the way the
wants it in his home'?
So we say about pickups as we have
always said about loudspeakers- listen
to all of them you can get an opportunity to hear and then pick the one
you like best. It's your ear that must he
satisfied, not anyone else's. Given a good
system, a good turntable, and a good
record, we are firmly of the opinion that
we could be satisfied with at least half
of the pickups described here. Change
the amplifier and speaker combination,
and we might choose the other half just
as quickly. We shall try to give you the
specifications and descriptions with relatively little comment as to our subjective
reactions. And we will never allow ourselves to get in the position of having to
say which pickup is which in a series
of listening comparisons. One thing we
believe firmly -practically any high quality pickup will give satisfactory
performance with practically any system, even though some tone control adjustments may be required to make it
seem entirely satisfactory to a given
person's ear. Just remember that there
roust be some good qualities in every
product or it would never have reached
the market-since the Manufacturer is
not likely to risk financial ruin with a
poor product; and if a product stays
on the market for any appreciable time
there must be plenty of people who
really like it.
One final comment -judge for yourself. lise the specifications as a guide,
but when it comes to laying out the hard
cash, make sure the product satisfies
you -not only in hi -fi but in everything
else you buy.
STEREO PICKUP CARTRIDGES
At this stage of hi -fi development, we
feel it is necessary to list only stereo
cartridges-by now, everyone who has
an interest in monophonic reproduction
will almost undoubtedly have acquired
a mono pickup. In general, stereo pickups will do a satisfactory job of reproducing monophonic LP -records provided
their two output circuits are paralleled,
which will cancel out all vertical components ( including turntable- induced
rumble). For the ultimate in monophonic reproduction, a top -quality mono
pickup will undoubtedly give better performance, although unless the entire
system is of the very highest quality it
is doubtful if the difference would be
apparent to the ear. Most people who
are buying pickups these days are choosing from the stereo models that are
available since it practically doubles the
total cost to have separate cartridges
for mono and stereo,-in addition to complicating the playing operation by necessitating a change from one to the other
as the records are changed.
69
Stereo pickups are of three basic
classes : magnetic, piezoelectric (crystal
or ceramic), and electrostatic or capacitance, sometimes called frequency modulated. Magnetic pickups are divided into
three types moving iron or variable
reluctance, moving coil, and moving
magnet. In all of these the output is
directly proportional (over most of the
range) to the stylus velocity in the
groove. Since their output is relatively
low-reaching a usual maximum at full
modulation of somewhere in the vicinity
of 30 my per channel -they require preamplifiers to raise their output level up
to a par with the high -level signals received from tuners and tape amplifiers.
These preamplifiers provide equalization
to compensate for the recording curve
on the record. Some packaged -set manufacturers claim their pickups do not require the "distorting" preamplifiers,
thus giving a false impression to the
buyer. Actually, since the frequency
response of the preamp is not flat, it
can be described correctly as having
"amplitude distortion," but the average
person does not know of this and he becomes frightened and unduly influenced
by the word "distortion." Distortion, as
usually understood, is likely to be less
than 0.1 per cent in a good preamplifier
at any normal output voltage.
All of the magnetic pickup types employ coils in some form or another, and
it is a common property of coils in a
magnetic field to respond to the field,
regardless of its source. Since phonograph turntables and changers all have
motors, there is some a.c. field in their
vicinity, and without proper precautions it is possible that some hum pickup may result. Shielding and coil structure reduce the susceptibility to external fields so that little if any trouble
is encountered from this source.
Piezoelectric pickups have considerably higher outputs-usually in the vicinity of 0.25 to 1.0 volts -and can
therefore be used with simpler amplifiers. Furthermore, they can be designed
so that they compensate directly for the
:
recording curve and little or no additional circuitry is required. This limits
the flexibility of the pickup circuits in
matching various curves, but the RIAA
curve has been practically universal for
several years, and is accepted by all
manufacturers of stereo records. However, when a piezoelectric pickup is fed
into a specified (relatively low) load
resistance, usually combined with a voltage divider, it may be connected directly
into a circuit designed for magnetic
pickups, since the low load impedance
makes the electrical output signal almost
identical with that of magnetic cartridges. This restores all the flexibility
of the preamp with its usual accommodation for many recording curves. The
values for the termination may differ
with each type of pickup, but the correct termination is usually specified by
the manufacturer. The piezoelectric
pickups are not susceptible to external
magnetic fields, but they are affected
by electrostatic fields because of their
higher impedances, and hum may he
noticed when a hand is brought in proximity to the pickup head. This may be
eliminated by using a metal head or by
shielding inside the head. Another successful method is to paint the inside of
a plastic head with silver paint, making
sure that the paint extends over a
ground terminal in the head.
To the best of our knowledge, there
are no electrostatic or capacitance -type
stereo cartridges on the market so ar,
although Weathers makes a mono Version which is a favorite of many users.
In general, this type of pickup requires
a specific type of associated circa-try,
reducing the interchangeability feature
of the other pickup designs.
Magnetic Types
Among the magnetic pickups the moving -iron or variable reluctance type. has
long been the best known. In this model
the magnetic fields reacting upon two
coils or two pairs of coils are caused to
vary as the armature or stylus bar, to
which the stylus is attached, moves from
side to side and /or up and down as the
stylus follows the groove.
In the moving -coil pickup, the signal
is generated in a tiny coil (or pair of
coils) located in a constant magnetic
field. As the stylus causes the coil to
move, the turns of wire cut through the
magnetic lines of force and the corresponding signal voltage is generated in
proportion to the velocity of the motion.
The principle of the moving -magnet
pickup is similar to the variable reluctance or moving -iron type, since the flux
flowing through pole pieces is caused to
vary as the stylus moves, although the
variation is due to moving the magnet
itself rather than a part of the magnetic
circuit. Some modern magnetic materials
can be energized to have strong fields
even in very small sizes, and thus the
moving mass of the stylus and the magnet can be relatively small. All design
of pickups is likely to be the result of
the magnet were larger,
compromises
greater signal output could he obtained,
but that would increase the mass too
much; more turns in the coil would give
greater signal output, but the increased
inductance would probably lower high frequency performance; heavier armatures would carry more lines of force,
giving greater signal, but the increased
mass would lower resonance well into
the audio spectrum. These are only a
few of the compromises that must be
made, and when one considers all of the
requirements of pickup design and the
practical construction of the various
models, it is a wonder that they all sound
as good as they do. Of course, we could
go hack through the recording stages
from microphone to cutting head, which
would simply serve to increase the
wonder that record reproduction is at
its present stage of excellence.
All pickup models listed are described
as to type, and specifications as to out-
-if
put, frequency response, stylus force,
and so on, are those furnished by the
manufacturer. Unless otherwise stated,
all net prices quoted are for cartridges
with diamond styli.
STEREO CARTRIDGES
AUDIO EMPIRE
Dynamzagnetic Stereo Cartridge. The Empire 88 utilizes the moving magnet principle
with a four -pole hum-balanced construction
for full channel separation, balanced highfrequency output on each channel, and hum free operation. This unit (which was described fully in the May. 1959, issue of AUDIO)
offers equally high compliance of
5 x 10-6
cmi
dyne both vertically and laterally, and will
track with stylus forces ranging from 2 to 5
grams. depending on the arm in which it used.
The stylus is changed by removing a single
screw which releases the entire stylus -armature- polepiece assembly, reducing the likelihood of damage in handling. Frequency response is from 20 to 20,000 cps ±2 db. with
an output voltage of 5 my for a stylus velocity
of 5 cm /sec. Channel separation, 20 db. Recommended load impedance, 47.000 ohms. Inductance, 500 mh resistance, 1000 ohms.
Four-terminal output normal stylus radius.
0.7 mil. ; other radii available are 1.0 and 2.7
mils., with all three in either diamond or
sapphire. Audio Empire, Division of DynaEmpire, Inc., 1075 Stewart Ave., Garden City,
N. Y. User net price, $24.50. Repla 'ement
stylus assemblies : diamond, $12.50 sa phire,
AUDIOGERSH
Stereotwin 210 /D stereo cartridge. The
latest model of the original Stereotwin 200
;
;
;
$6.50.
AUDIO
70
www.americanradiohistory.com
AmericanRadioHistory.Com
s
SEPTEMBER, 1959
which introduced the moving- magnet principle
first in stereo cartridges. Under average home
conditions, frequency response is within ±2 db
from 30 to 18,500 cps without resonant peaks,
and signal output is 12 nn- per channel at a
stylus velocity of 5 cm /sec, which with mumetal shielding results in extremely low hum.
Compliance is 4 $ lie' cm /dyne, and the recommended load impedance is 37,000 ohms.
Channel separation is in excess of 20 db,
and recommended stylus force is 3 to 5 grams.
Unit is held in spring clip, and is removed
from clip for greatest ease in mounting. Design of clip provides for optimum stylus position with either turntables or record changers,
Four terminals, easily replaceable stylus without tools. Audiogersh Corporation, 514 Broadway, New York 12, N. Y. User net price,
$34.50; Stereotwin 209, $44.50.
my per channel for a stylus velocity of 5
cm /sec. Channel separation is better than 22
db. and tracking force is from 2 to 4 grams.
Recommended load is 47,000 ohms for rated
7
input of a preamplifier. Compliance is 3.5 x
10-s cm /dyne, and effective mass is 2 mg at
the stylus tip. Element capacitance is 250 µµf
per channel and tracking force is 3 to 4 grams.
The arm is attractive in appearance. Lias a
tracking error of not over 2 deg. on a 12 -in.
record. The knob at the back raises and lowers the stylus from the record without offering
any turning nomment to the arm, staking it
easy to use with no chance of damage to the
record grooves. The base of the arm is adjustable to accommodate turntables of differing
heights. Finished in glossy black with anodized aluminum trim. Distributed in the U.S.
by Ercona Corporation (Electronic Division),
16 W. 46th St., New York 36, N. Y. User net
CBS -HYTRON
Constant Displacement Stereo Cartridge.
Four versions of this ceramic pickup have been
introduced -with either diamond or sapphire,
and either in -phase or out -of- phase -these
terms referring to the phasing of the two
channels of the ceramic element. In -phase
cartridges, SC -1, provide conventional phasing
of the output signals for each channel, which
permits the use of the cartridge with either
stereo or monophonic records in any dualamplifier or conventional stereo amplifier system. or it can be used in monophonic systems
frequency response. The unit employs an unusual construction, with the entire moving
element being enclosed in a plastic cone
permanently attached to a metal shell surrounding the body of the cartridge. It is
mounted at an angle, as shown. The mechanism consists of a light ntumetal cross which
is attached to a slender aluminum tube with
the stylus affixed to the end. Four terminals.
T.4-12 Unitized Arm- Cartridge. A similar
unit to the Stereodyne II is united with a
novel arm for use with turntables to work
with minimum stylus force, which is adjust-
price, $59.50.
DUOTONE
"Floating Needle" Stereo Cartridge. Made
by Acos in England, the GP71 single -stylus
cartridge has a frequency response of 20 to
17,500 cps with an output of 1 volt. Channel
separation is 20 db, and compliance is 2 x 10-0
cm /dyne. This model is designed for mounting
in Garrard, Collaro, and BSR Monarch record
changers, and is furnished with three terminals.
Tornorer model (P7$. Designed for use
where standard grooves must be played as well
as LP and stereo records, this model has a
frequency response of 40 to 15,000 cps
± 1.5
able. Unit mounts in
single hole. Distributed
N. 41st St.,
Philadelphia 4, Pa. Her net price: Stereodyne
II. $29.50: TA -12. $49.95.
in the P.S. by
a
Dynan Inc.. 617
E
S
L
Coro /Jewel Stereo Cartridge. Utilizing a
tiny mechanical gimbal and two d'Arsonval
type movements mounted at angles of exactly
90 deg., the ESL ('100 Gyro /Jewel cartridge
has it response which is inherently linear. Frequency response is 20 to 20,000 ells + 2 db,
and output is I niv for a stylus velocity of 5
cut /sec at an impedance of 25 ohms at 1000
by connecting the cartridge outputs in parallel.
The out -of -phase condition, Model S(' -2, is
used with certain types of two -way stereo
amplifiers in which a single push-pull output
stage handles both channels, with the matrix ing of outputs being done in the secondary
circuits of the necessary two output transformers. In -phase models are maroon, out -ofphase models are gray. Frequenc'y response. :30
to 10.000 cps +;1 db channel separation, 20
db; stylus force, 5- 7 grants. Compliance, 2 x
10-0 cm/dyne capacitance of each side, 500
µµf. Output voltage, 400 air at stylus velocity
of 5 cm /sec. Stylus radius, 0.7 mil.
Profe.ssimial 55 Model. Offered with a 0.5mil diamond, and only in the in -phase condition, this unit is housed in transparent plastic,
and is furnished with two plug -in equalizing
networks. Specitications are the same as for
models S(' -1 :MI N(' -2 except for frequency
response, which k 20 to 15.000 cps +3 db.
Styli can be replaced by the user tvith only a
small screwdriver needed. ('IBS Electronic
Sales Corp.. Division of CBS. Inc., 100 Endicott St., Danvers Mass. User net price: Models
SC-1 and SC -2. $24.:' Professional 55. $28.95.
;
;
:
CONNOISSEUR
Integrated Arm and Cartridge. Fitting only
into the manufacturer's arum, the new stereophonic pickup by Connoisseur is of the ceramic
type, and employs extremely small units
coupled to a minute cantilever system and
fitted with a diamond having it tip radius of
mils. 1're,luency response is 20 to
20,000 cps ±2 db, and output is 20 niv when
feeding the recommended load resistance of
50,000 ohms, which will give constant-velocity
characteristics and thus make it possible to
feed the output into it conventional magnetic
0.5 0.6
AUDIO
SEPTEMBER, 1959
db and an
output of I volt. Compliance is
cm/dyne and channel separation is
at 1000 cps. Four -pin construction, with
2--4 gram tracking force. Distributed in the
U.S. by Duotone Company, Inc.. Locust St.,
Keypot-t, N. J. User net prices GI'71, $18.75
4 x 10-0
25 db
1
:
;P7:;, $20.70.
DYNACO
Stereodyne II Cartridgr. Iitilizing the variable reluctance principle. this cartridge made
by Bang and Olufsen of I)enmtark is designed
for superior reproduction from either mono or
stereo microgroove records. It has a frequency
response from 30 to 15,000 cps ± 2db, compliance of 5 - 10-i cm /dyne. and an output of
cps. Reconuueuded tracking force is 2 .4 grams.
The unit is simply lioninted on an adapter
plate using only one strew. the plate being
attached to the usual pickup head with ttvo
screws with normal spacing.
l'rofc.vxineinl ,Stttio I'artrid! /r. The same
type of nteehanism is also :available to fit the
professional series arm. with the designation
I'100. Both models are normally used with
step -tip transformers to provide an output
Comparable with most stereo cartridges, but
Wit II preantps of high gain and low noise, the
cartridge may be fed directly into the phono
inputs. Electro -Sonic Laboratories, Inc., 35 -54
Stith Sr., Long Island City 6, N. Y. user net
prices: ('100, $69.95; P100, $79.95; 310S arm,
$57.01).
ELECTRO -VOICE
.11 'tr-ro- -lion() Cartridge.
.11agnerantie
ploying (Trainie elements
ill
Em-
connection with
71
1304 employes a diamond LP stylus and a
sapphire standard stylus, whereas Model 1303
uses sapphires in both sides. Electronics Dis-
tributor Division. Erie Resistor Corporation,
Erie, Pa. User net prices
:
1304, $16.50
;
1303,
$8.95.
FAIRCHILD
Compatible
Rotating-Magnet
Cartridge.
Model SM -1 is a moving -magnet pickup of
unusual design. The stylus bar extends from
a precision -ground rubber "ball" in which the
magnet is mounted, (the ball constituting the
suspension and damping), generating the
signal in two sets of coils. Frequency response
is from 20 to 15.000 cps ±2 db, and output
is 11.5 mv for a stylus velocity of 5 cm /sec.
The unit has a d.c. resistance of 2000 ohms
and an inductance of 0.5 Hy, and is designed
to operate into a load of 47,000 ohms, with
a special printed circuit which is an integral
part of the cartridge. the Magneramic 31 is
designed to be fed into the usual magnetic
pickup inputs of stereo preamps. Frequency
response is given as 20 to 20,000 cps ±2 db,
with a channel separation of 28 db at 1000
cps and an output of 10 nn-. Compliance is
3.5 x 10-e cm /dyne and the cartridge is available with either 0.5- or 0.7 -mil styli, the
former being recommended for use with transcription arms with a stylus force of 2-4
grams. The cartridge is also available for
ceramic inputs.
2O- series Stereo Cartridges. The original
E-V ceramic pickup is available in both- standard and Magneramic models -the former with
an output of 500 mv and the latter with a
velocity characteristic and an output of 20
mv. Frequency response is 20 to 20,000 cps
+ 2 db, and recommended tracking force is
5 -7 grains in changers. 4-6 grams in transcription arms. Model 21D is standard series,
with 26DST comprising the same elements but
any value from 39,000 to 100,000 being ac-
GOTHAM AUDIO SALES
ceptable. Recommended tracking force is 3 -4
grams. Channel separation is better than 25
db at 1000 cps, and compliance is 4 x 10-0.
Because of internal copper case for electrostatic shielding and a mumetal outer case,
the hum is extremely low, being 65 db be ow
the signal when mounted on the 'Watt( le.
Fairchild Recording Equipment Corp., 1 40
45th Ave., Long Island City 1, N. Y. User
net price, $34.95.
Neumann Double-Dynamic Cartridge. Developed by Neumann specifically for calibration of stereophonic disc recording, the Model
DST was not originally intended for general
consumer sale. They are designed to fit only
such arms as the Ortofon (ESL Professional)
or Neumann PA -2 types. When used with the
former a special four- contact insert and
holding clip must be ordered under the number Z -15. The cartridge has a frequency response of 30 to 15,000 cps +2 db and an
output of 0.75 my for a stylus velocity of
5 cm /sec. The output impedance is 18 ohms
and should be fed into a load impedance of
greater than 50 ohms. Channel separation is
greater than 25 db in the midrange, and
greater than 12 db over the full audio range.
Compliance is 3.6 x 10-0 cm /dyne, and a tracking force of 6.5 grains is required. Stylus
radius is 0.6 mils. Use of an input transformer is recommended, with Bever Type
TR- 145/15 having a turns ratio of 15 :1 as a
suggested model. Gotham Audio Sales Co.,
Inc., 2 \\"est 46th St., New York 36, N. Y.
DST cartridge, $69.00 ;
User net prices
Bever transformer, $11.20.
:
GENERAL ELECTRIC
Variable Reluctance Stereo Cartridge. With
a series of small changes in the design. the
new VR-22 stereo cartridge is even better
than its predecessor with respect to output,
channel separation, and extended frequency
GRADO
poring -Coil Stereo Cartridges. Made in
two models, the Custom for use in record
changers and the Master for turntable use.
in a turnover mount accommodating a 3 -mil
sapphire in addition to the 0.7 -mil diamond
for LP's. Electro Voice, Inc., Cecil and Carroll
Sts., Buchanan, Michigan. User net prices
Magneramic 31, $24.00 same, for ceramic
inputs, $22.50 21D, $9.00 26DST, $9.90.
:
;
;
;
ERIE
Single- Element Ceramic Cartridge. Using a
tiny ceramic tubular element with suitably
placed electrodes, the Erie turnover cartridges
accommodate both LP and standard records.
Frequency response is 20 to 16,000 cps ± 3 db
and the output is 500 mv at a tracking force
of 5 grams. Channel separation is 20 db. Model
response. and the two channels balance w thin
± 2 db to 15,000 cps. The shielding has been
improved. and the grounding of the shiel and
the method of shorting the two "ground"
terminals are well thought out. Available in
two models, VR225 with 0.5 -mil stylus and
VR227 with 0.7-mil stylus. with the former
tracking at 2 -4 grams in transcription arms
and the latter at 5 -7 grams. Frequency response. 20- 20.000 cps ±3 db for the VR225,
and 20- 17,000 cps ±3 db for the VR227.
Channel separation is up to 30 db at 1000
cps. and output is 9 mv for a stylus velocity
of 5 cm/sec. Inductance if the unit is 420 mH,
nominal. and resistance is 1600 ohms per
channel. Recommended load resistance is 47,000 ohms. Lateral compliances are 4 x 10-0
and 3 x 10-3 cm /dyne and vertical compliances
are 2.5 x 10-0 and 2 x 10-0 for the 225 and 227
respectively. Audio Components Section, General Electric Company. Auburn, N. Y. User
net prices : VR225, $27.95 ; VR227, $24.95.
these cartridges are similar in design. Both
employ a moving element consisting of a
hollow plastic cube on which are wound two
coils and from which extends the stylus bar.
This cube is supported in a rubber "grommet"
which serves to hold the coils in the magnetic
field as well as provide the necessary damping. The specifications given are for the Custom and Master series respectively. Frequency
response. 10- 24.000 cps and 10- 30,000 cps.
Interchannel output balance, 0.5 db on each :
frequency balance, 0.5 db each. Output, 3.5
mv and 2.5 mv respectively at n stylus
velocity of 5 cm /sec. Impedance, 1000 and
700 ohms ; Tracking force, 3 grams each.
Input load. any value over 5000 ohms for
both models. Channel separation, in excess of
20 db and 25 db. In addition, the Master
series is fitted with a radioactive element to
reduce static accumulation on the record sur-
face. Grado Laboratories. Inc., 4614 Seventh
Ave.. Brooklyn 20. N. Y. User net prices :
Custom, $32.50 ; Master, $49.50.
AUDIO
72
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
duit' of 4 x It) cut /dyne. The Custom model,
171), has an inductance of 400 utli. a d.c.
resistance of 400 ohms. and a compliance of
3.5 ln
van /dyne. 1111111 have four terminals
and lit standard 'moulting dimensions. `hure
Brothers. Inc.. 222 Harirey .Ave., Evanst mt,
Hl. User net prices: Ai2l2 :und 1216, $89.50
KNIGHT
KN500 .Magnetic Stereo Cartridge. 'Chis
unit has a frequency response of 20 lo 20.000
cps +2 db with a compliance in both vertical
and literal directiuus of 4 x 10" ciii'dyne,
anti an output of 5 ntv per channel. Channel
separation is more than 20 db. and the recommended load impedance is 47,01111 ohms.
a'
London Recording Laboratories and the H. H.
Scott engineering, staff. Frequency response
or 29 to 18,000 cps + 2 db. and compliance is
3.5 x 10- cm /dyne. Output is 7 my in the
stereo connection. Stylus radius is 0.5 nail,
and output impedance is 4000 ohms per
channel at 4itii cps. Recommended load is
47,000 ohms, and channel separation is better
than 20 db. Tracking force. ti.,a grants. The
over -all length of the arm is 12t/, in., and
the height adjustment range is
to 21,:j, in.
above the mounting board. The assembly is
complete with arm rest and all mounting
hardw :ue and templates, as well as all connecting cables. II. II. Scott, Inc., 111 Powder
Ili11 Road, Jltiyuurd, 'Lass. User net price,
$S9.95.
SHURE
The cartridge itss four terminals, and uses
a 0.7 -nail diamond. Tracking force is 2 to 5
grams. .AIlied
corporation, 100 N.
Western :Ave_ t'hicam sn. 111. Yser net price,
ÿl0.8:1,
PICKERING
Col/cc/or .vrh.. .f,'i). IIerntetically sealed
nad fully eucautsutlutted in mumetal for hum free performance, the new Collector Series
:180 P'luxvative has two compliance ranges
the "A' type V- guard stylus for transcription
arms, nad the "C" type l'or record changers.
-
,Studio I)!nu'tiv Reproducer.
Combining the
moving magnet principle with arms of excellent design, Models \1210 (Ili in.) and
M212 (12 in.l provide excellent reproduction
at s'ylus forces ranging from 1.5 to 2.5 grams.
Prequency response, 20 to 20,000 cps + 2 db
at an output of 4.5 mt: recommended load
impedance, 47.O00 taints. Higher values of
load impedance will produce a slight increase
in high -frequency response. Inductance is 400
mil and tl-e. resistance is 600 ohms per
channel. Lateral and vertical compliance, 9 x
each
:
A1:3It.
$ +5.00
;
M7D,
24.00,
SONOTONE
Series ",87" C,rirnaic ('artridgcs. Designed
for use with records cut to ItIAA characteristics, these cartridges will give at response
flat within ± 1.5 db to 15.0041 cps with a
smooth rolloff to 2t,1100 c.rs when used with
simple loading networks. Working into a flat
amplifier with an input resistance of 3.3 ategohnts, a network consisting of a 600 µµf
capacitor in series with 1.5 ntegohuts will give
rated response. A flat amplifier with an input
resistance of 2.2 ntegohnts will give response
within +2.5 tilt up to 1000 cps. together with
rated response above that point. Per magnetic
inputs, the network should he composed of a
parallel combination of 68,0110 ulnas and .001
µ f, connected in series Willi 27.000 ohms, with
the amplifier being fed from tlta junetion of
the two resistors. In the fat amplifier eon neetiott. the output voltage is :i85 ntv for a
stylus velocity of 5 cut /sec. while for the
magnetic inputs. the resistance of the input
controls the output voltage; for an input
resistance of 10,000 ohms. output is 10 mv;
for :3,000 thins, output is 20 nn : and so on.
Ready -made net vyolks are available. Coatpli-
duce is 3.0 x I0- cm /dyne, and channel separation is 20 db at loon cps. Stylus force should
Response is fiat from 20 to 20,000 cps ±2 db,
and channel separation is 25 db or better.
Output is 111 nit for at stylus velocity of 5
cot,bec. Cartridge has four terminals plus an
ol tiuual metal-ease ground to prevent ground
loops vtill metal arms. Unit is available as
Iio tel 380P:, the "('olleetor's Ensemble," which
includes the Pluxvalve body with three
\_-Guard styli- une each for stereo, LP, and
standard, in transcription arms: as llfodel
380.-A for stereo and LI' only in transcription
arms and as \[edel 389(' for stereo and LI'
in record changers.
.,!nitr/ 196 l'aipoixe Arnt and Pickup. An
integrated assembly of a ytndel 371 stereo
cartridge with the I-niptise area, this combination employs a single friction -tree pivot
;
3-5 grams with transcription arms, and
from 4 to lì grams for changers. Available
models include various combinations of diamonds and sapphires in turnover mount to
accommodate stereo, 1,1', and standard records. Model STA -4SD has a 0.7 -nail diamond
and a :t -mil sapphire. Electronic Applications
Dit'isitin. Sono one Corporation, Elmsford,
N. Y. User net trite, A14111c1 8'í'a -4S1), $11.70.
be
10-1 cm /dyyne
;
channel separation, more than
20 db at 1000 cps. The arm is mounted so as
to place its bottom edge 9/32 in. above the
record surface, and the pickup is raised and
lowered with a finger tip on the button near
the front of the arm. 'I'he arm counterbalance,
though not needed for actual balancing since
the turns does not move in it vertical plane, is
attached by a flat steel spring which is
damped to eliminate the usual low- frequency
arm resonance. All load -bearing pivots are
ratty .jeweled.
Profe.sxioital and Custom I)gneties. These
two cartridges are designed for mounting in
transcription arms and in record change s
respectively. Both have frequency responses
TANNOY
"Pori- 'I't-in" Variable Reluctance Cartridge.
With tooting parts ha ring very low dynamic
Maas, the Tammy stereo cartridge takes the
form of It plastic molding which enelosts the
211 to 15,0110 cps, + 3 db, outputs of 5 my
per channel, dad channel separations of more
than 20 db at 1000 cps. Recommended load
ul'
impedance is 47,000 ohms, The Professional
model, 113D, has an inductance of 365 null,
a d.c. resistance of 330 ohms, and a compli-
SCOTT
generating systems, with a not nt etatl shield
against hum. Frequency response is from 30
to 15.n0t cps + 1.5 dh. and output is 7 ntv
per channel. lkecouuueudd load resistance is
1110,111111 ohms, with 50.000 ohms as the minimum. The unit has an iuductnnit' of 350 liebt
in each channel, and tracking force is 4
grants. Channel separation is a maximum of
London -.Scott Ann and Cartridge. This new
magnetic pickup and arts combination was
designed with the combined e(hurts of the
Cartridge mounts in any standard head. Tau noy (America) Ltd., Box 177, East Norwich,
L. I., N. Y. User net price, $43,50.
strikingly aittratctive design for use with
turntables. Pickering & Company, Inc., Plainview, N. Y. User net prices 380E, $00.00;
3811A, 534.541
380C, $29.85; 1911, $49.50.
in a
:
;
AUDIO
SEPTEMBER, 1959
27
db
at
4000
cps.
_S
db
at
11100
cps.
73
WEATHERS
StereoRamie Cartridge.
new development
A
in ceramic pickups, model C -501 -D is designed
for use in changers and transcription arms
and combines low cost with high- quality
sound. Frequency response is 15 to 30,000
cps. compliance is 6 x 10-8 cm /dyne, and
accurate stylus pressure adjustment from 0
to S grants ; maximum vertical and lateral
compliance by means of precision ball bearings : resonance below threshold of auditility ;
arm lift an integral part of arm asse nbly
interchangeable shell accepts all standard
cartridges patented self -latching arm rest,
and lowest possible tracking error. Indio
Empire Division of Dyna- Empire, Inc.. 1075
Stewart Ave.. Garden City, N. Y. Use' net
:
price. $34.50.
E S
L
pro/ Balance Tone Arm. Designed oa the
principle that an arm should be balanced in
every plane and the stylus force provid td by
a spring, the ESI. Gyro /Balance arm has
many advantages. Because of this design.
turntable leveling is unnecessary. an I on
demonstration the ESL arm is often siown
playing records with the turntable in an
absolutely vertical plane-in fact, if it were
c
channel separation is 25 db. Output voltage
is 170 my for a stylus velocity of 5 cm /sec,
and is intended to be fed into magnetic pickup
inputs on standard preamplifiers. Unit is also
available in Weathers Micro -Touch arm fully
assembled as Model MC -1 -D. Weathers Industries, Division of Advance Industries, Inc.,
66 E. Gloucester Pike. Barrington, N. J. User
net prices. C- 501 -D. $17.50 MC -1 -D, $55.95.
;
ARMS
AUDAX
s'tereo Tone Arm Kit. If you can use a
screw driver, you can assemble this professional -type tone arm in just 15 minutes. No
mechanical skill is needed. Precision -engineered to broadcast standards, it offers savings of over 50 per cent because you assemble
it yourself. Only two moving parts-vertical
and lateral pivots-give this arm remarkably
free motion. Stylus pressure is easily adjustable. Calibrated offset angle assures tangency
to the groove. Plug -in shell accepts all standard cartridges. Audax. Division of Rek -O -Kut
Company. Inc.. 38 -19 108th St.. Corona 68,
N. Y. User net price, 12 -in. KT -12 kit. $15.50
16 -in. KT -16 kit. $18.50.
AUDIO EMPIRE
Balaar,d s't,r,,, Transcription Arm. The
Empire :it, a, hh,ves dynamic balance in all
planes to keep the stylus in proper position
even it' the turntable is tilted or a record
badly warped. Offset pivot design maintains
center of mass balanced over pivot in all
planes. Other features of this arm include.
possible to keep the record and platter in
place and provide proper bearings for the
turntable itself, the arm would play records
upside down. Ball bearings are used throughout for all vertical and horizontal motions,
assuring smoother operation, increased record life, and longer trouble -free performance.
In operation, the spring force is reducel to
zero by turning the two knurled knobs tack ward ; the sliding weight at the back is :hen
adjusted for perfect balance of the arm and
cartridge. The knobs are then turned forward
to obtain the desired stylus force. The _lead
is of molded plastic and is fitted with four
terminals. A wire lead ground is carried
through the assembly for connection bo a
terminal strip under the turntable base. Stylus
force adjustable from zero up to 8 grams.
Electro -Sonic Laboratories. Inc., 35 -54 16th
St., Long Island City 6. N. Y. User net plce,
$34.95.
FAIRCHILD
Stud io- Qualitlt Stereo Arm. Embod7ing
many refinements and improvements in the
well -known Model 280 monophonic tone arm.
the new Model 282 is especially suitable for
stereo use. Although intended primarily for
use with Fairchild cartridges which it accepts
as direct plug -ins. it is easily adaptable to
many other cartridges with adapters supplied.
Improved bearing action lowers pivot friction
and hysteresis. Dual output leads are in.orporated in the unit, each set shielded to --irevent interaction. as well as a separate gro utd
lead insulated and isolated. Exceptionally ow
tracking error. This arm will meet studio
standards in every respect. Fairchild Recording Equipment company, 10 -40 45th Ace..
Long Island City t. N. Y. t'ser net pr ce,
$42.50.
GARRARD
Precision Tone Arm. Despite its molest
cost the new Garrard Type TPA /12 will give
completely satisfying performance with eit mer
monophonic or stereo records up to 16 ins.
in diameter. Practically friction -free movement is assured by use of precision spring loaded cone -type ball -bearing pivots. Suitable
for use with any turntable. the TPA /12 is
stereo -wired and the plug-in shell will accapt
any standard cartridge. A new simple weight
adjustment is easily accessible, and permits
precision control of tracking force. The factures of static balance, spring loading, fnd
viscous damping have all been combined in
the TPA /12 to give a remarkable measure of
audio performance. Garrard Sales Corporation, Port Washington, N. Y. User net price.
$19.95.
GENERAL ELECTRIC
"Stereo Classic" Compatible Tone Arm.
Every design feature of this tone arm is
directed toward optimum performance from
stereophonic records. These design features
also give the Model TM -2G outstanding
monophonic qualities. The arm was developed
specifically for use with G -E cartridges. as
an integrated all G -E pickup system. The
arm's primary feature for excellent stereo
reproduction is its static balance. When adjusted, the arm maintains its lateral equilibrium at all times, even if the turntable is not
perfectly level. An unusual two -step trackingforce adjustment is used for (1) balancing
the arm to zero tracking force, and (2) for
making a precise tracking-force adjustment
between zero and six grams. Among other
features are a built -in arm rest. au easily
removable cartridge head, a terminal board
with four stereo lead terminals and one
ground terminal, and trim, modern styling
with brushed aluminum and chrome finish.
Accommodates records up to 12 ins. in diameter. Specialty Electronic Components Dept.,
General Electric Company, West Genesee St.,
Auburn. N. Y. User net price, $29.95.
GRADO
"Micro -Balance" Stereo Tone Arts. Engineered as a mate for the Grado cartridge, this
arm is constructed of finest gunstock walnut
wood. Metal fittings are made of finely machined anodized aluminum. By utilizing a
special micrometer overhang adjustment. the
user may adjust the arm for the smallest
possible tracking error-±0.8 °. A second micrometer adjustment accurate to 0.1 gram, is
used for setting tracking force. Lateral pivoting of the arm consists of a precision ball
thrust bearing. This shaft and bearing assembly is designed to damp out effectively
the low- frequency resonance which occurs at
10 cps when the arm is used with a Grado
cartridge. Pivot frictions are under 0.1 gram
at the stylus. The arm is wired with four
shielded conductors. Grado Laboratories, lime.,
4614 Seventh Ave., Brooklyn 20. N. Y. User
net price 12 -in. tone arm, $29.95 : 16 -in.
transcription arm, $32.50.
:
GRAY
Fluid -Damped Stereo Arm. Linear fluid
damping in both vertical and lateral planes is
featured in the Gray Model 212 -SX stereo
AUDIO
74
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
tone arm. Precision balanced for maximum
tracking stability, the unit incorporates such
features as adjustable static balance and n
quick-change holder which will accommodate
all standard cartridges. Pour leads are included for stereo operation. Tracking error
is reduced to au absolute minimum. Available
fully assembled or in kit form, this arm will
meet every demand of the most discerning
music lover. Gray High Fidelity Division, 16
Arbor St., Hartford 1. Conn. User net price:
Jiudol SX -12, 12 -in. tone arm fully assembled,
Model SS -16, same except for 16 -in.
records, $36.50 ; Model SAK -12, same features
ns SX -12 except in kit form. ('tun be assembled
and wired in 25 minutes. $23.95.
;
RECOTON-GOLDRI NG
Iroi for Ntevrn or Munn ('ortridyes. Made
of cast aluminum and with Nylon trimming,
the vertical movement of this arm is on hard-
ened cone bearings while lateral movement is
on steel halls in Nylon cone bearings. Height
is adjustable to suit all modern motor units,
and stylus force is adjustable from zero up-
wards. The head arrangement is designed to
:cccuutnuulate all cartridges with standard
mounting dimensions, the cartridges
being tirst mounted on a head slide which is
instantly removable from the arm. Four terminals are provided, and additional slides
may be obtained. The G -60 arm is designed
to mount with its spindle S?/- in. from the
turntable spindle, which gives it an overhang
of 15/32 in. The offset angle is 21.5 deg.. and
tracking error clues not exceed 2 (leg. over a
12 in. disc. Recoton Corporation, 12 -35 Barnett Ave., Long Island City 4, N. Y. User net
prices. G -110 arm. $19.9:1: extra head slides,
REK-O-KUT
Steno Tone Arras. Although similar in appearance to the earlier Rek -O -Kut monophonic
arms, these units have been completely redesigned for stereo. Mass of the shell has been
increased to lower the point of resonance.
Larger, heavier counterweights are employed,
and a 4- conductor head accommodates all 3-
and 4- terminal stereo cartridges. A 4 -prong
shell facilitates phasing. The unit is furnished
with wires already connected to a terminal
strip. Such desirable features as friction -free
micro-bearing pivots, and micrometer -type
counterweight adjustment, have been retained. Rek -O -Kut Company, Inc 38-10 108th
St.. Corona 68, N. Y. User net price : S -120
12 -in. arm, $27.95 ; S -160 16 -in. arm, $30.95.
Extra plug-in shell, $5.95.
MICROPHONES
ALTEC
CAPPS
II irruph on( n'rtrluto. The Jlodel
condenser microphone
steul provides
all of the outstanding features of the well known Altee M -11 system, with the latest
developments in miniaturization and printed circuit applications making it one of the
smallest quality microphones on the market.
audio ('onden.<er Microphone. ('ustonebuilt for major recording studios, broadcast
stations, and technical and scientific applications, the Capps "Studio" model itierophone
is one of the most versatile in its field. It is
acoustically faithful to the most complex
wave form, free from angular discrimination,
blast- proof, and unaffected by moist atmosphere. Extremely modern in finish and form,
it is supplied with a chrome swivel as a standard accessory. Both microphone and power
supply are equipped with Cannon connectors,
"l.1 p. +ti1:"
M -2U
grains. The extremely small mass eliminates
resonances within the audible range. The unit
is bidirectional, which allows controlled discrimination of the pick -up area and facilitates
a natural balance of the primary pick -up with
room acoustics. When used with the StereoSpacer-an acoustically absorbent "partition"
between the microphones -these units provide the effect of 111 -ft. separation while
avoiding unnatural ping -pong effects typical
of poor stereo. :k :;- position switch provides
music, speech, and off positions, and a built -in
transformer enables operation at 50, 250, or
high impedances. Model 50 is identical in all
Particulars except output impedance, which
is fixed at 50 ohms.
It is literally no larger than it lipstick, and is
entirely unnoticeable when mounted on a
regular microphone stand. In addition, it is
equipped with a fountain pen clip so that it
may be carried on the coat lapel ur tie. or
hidden beneath the tie a corsage. or other
clothing accessories. Its quality and ruggedness :ire without peer.
Cil ARAC"l'P.IIISTICS
Frequency range 211 o 15,11110 cps.
Pattern Omnidirectional.
i'nlncit :ace ti µµf.
Output at 600 ohms: 49 dbm /1tI dynes /cur.
t autput
impedance 30, 150, 600 ohms balanced 311. 150, 600, 10,000. ohms unbalanced.
Power iequireutento: 117 volts 60 cycle a.c.
15 watts.
I'ser net price. complete system including
Typo l' -:u25A power supply and 10 -ft. iuter-
t'1 L1It.kC1'ERlSTl
Frequency range: 30 to 15,0UÚ + a db.
Pattern Omnidirectional.
Output impedance Av iilable in three models
CM-2030-30 ohms C.11-2250-50 ohms
CM-2011 high impedance.
Itimeusiuus: 'i't "1r I1/s "dia.
Capps and Company. Inc., 20 Addison Place,
Valley Stream. N.Y. User net price. $225.00.
639A Cardioid, three patterns
639B Cardioid, six patterns
633A Dynamic, non -directional,
633C Dynamic, non -directional,
Ribbon .tiicrupbotte..s. Suitable for the highest quality recording and brondcasting applications, the Dynaco -B lt O Model 53 microphone uses a replaceable duralumin ribbon
only .11001 in. thick and weighing 1.3 milli-
:
I
:
:
:
:
coiiecling cable, $236.00.
30, 150/250
AUDIO
300,w
$250.00
250.00
69.00
78.00
SEPTEMBER, 1959
:
.
:
:
:
I'IIARACTP.RISTICS
Frequency range 30 to 13,000 cps, + 2.5 db.
Pattern Bidirectional
Output impedance Yfodel 53 -50, 250, or
high _Nudel 50-5 ohms.
Dimensions: 7 t14 " X 1 :i! i;" dia.
Dynaco. Inc., 617 N. 41..t St., Philadelphia 4,
Pa. User net price. Moolel
$59.95 Model
:
:
:
1
:
I
I
:
50.
!.4-
19.95.
DYNACO
EL ECTRO-VO IC
77n attrrnpl)uttr.. .ìn,r'n
netrc.ct modrl... ltrreut..t
unique design
6¡¡
E
herr nre
of
their
lcutarc.v, eapeeimlty the
It ich is certain to influence TV ntik-
75
ameter of the acoustic tube virtually eliminates distortion of the sound flelfi. The
mouthpiece position may be widely adjusted
by a pivot in the spherical base which contains the moving-coil transducer.
25 db rejection to
ink techniques, they are listed in this
section although complete specifications
were not arailable at "press time.
"Sound Spot" Microphone. A new concept
ill directional microphones. the Model 644 was
designed to operate at considerable distances
from the sound it is picking up. For this
reason, it will permit a far greater degree of
TV camera flexibility than has heretofore
been possible, especially in intimate dialogue
scenes where camera placement has been governed largely by the ability of the microphone
to pick up voices of the performers. The 644
uses a combination cardioid and distributed
front opening, enabling it to maintain proper
response far away from a sound source. Its
front effective acceptance angle is 45 deg. on
each site
,.,center. Random noise cancellation from the rear and sides exceeds 20 db.
Frequency response is smooth from 40 to 12,000 cps. Weight is 2 lbs. 9 ozs. Electro- Voice,
Inc., Buchanan, Mich. User net price, $66.00.
.
Almost In risible Microphone. The Model
652 was designed for applications where microphones should not he obvious. It is a dynamic microphone mounted on a thin, nonreflecting tube. It can be used with equal
CHARACTERISTICS
Frequency range 50 to 10,000 cps
Pattern : Omnidirectional.
Internal impedance 200 ohms.
:
± 3.0 db.
:
Output level -55 db.
Probe length : 18 ins.
Base diameter 21/2 ins.
Weight 114 lbs.
:
:
:
Broadcast/ Recording Microphone. This excellent moving -coil microphone will easily
meet the most exacting professional requirements for music and speech. A socket at its
bottom permits connection to the table-top
hase supplied, or to a camera tripod. Although
regularly used by many European broadcast
and recording studios, the surprisingly low
price of the ESL -MC1 is within the reach of
home recording enthusiasts.
extraneous sounds in the
studio. Its pure nickel dual -diaphragms are
impervious to influences of heat and humidity,
being able to withstand the hottest lighting
any film or TV set can produce. Since the
entire impedance matching amplifier, including output transformer, is located inside the
microphone housing, the microphone may be
used as much as several hundred feet away
from its power supply. The KM-53a is identical in size but omnidirectional in pattern.
It is recommended for the recording of pop
orchestras where close -up microphone technique is employed. In such applications, omnidirectional microphones are employed to
prevent overloading the console and microphone amplifiers. An accessory, the Z -29
Overload Protector is advised for all applications of the KM -53a and KM -54a in high
intensity sound recording.
CHARACTERISTICS
Frequency range: 30 to 15,000 cps.
Pattern KM -53a- omnidirectional. KM-54a
-cardioid, with front -to -hack ratio
greater than 25 db.
Sensitivity 1.2 my /dyne/cmm.
Impedance 50 or 250 ohms (specify when
ordering)
RMS harmonic distortion Less than 0.8 per
cent over entire range to 110 db intensity level.
Finish Matte satin chrome.
Dimensions 4%" x 1/s" d.
Weight : "3.5 ors.
User net price, complete system consisting of
microphone with Type NKM Power Supply :
KM -54a, $435.00 ; Km -53a, $415.00.
:
:
:
.
:
:
:
CHARACTERISTICS
Frequency range 50 to 15,000 cps ± 3.0 db.
Pattern : Omnidirectional.
Internal impedance 200 ohms.
Output level -47 db.
4%" I x
Dimensions (plus base)
square.
Weight (plus hace) 8 ors.
35-54
Inc.,
Electro -Sonie Laboratories,
Thirty -Sixth St., Long Island City 6, N.Y.
User net price, $42.50.
1
:
effectiveness for Ty. lectures, and broadcasting where it is desirable that the view of the
speaker's face not be obstructed. For added
articulation it utilizes two clear plastic baffles
to give either a 6- or 3 -db boost in the brilliance range of 6000 cps. Output level is -60
db. Weight is 11 ors. Electro- Voice, Inc.,
Buchanan, Mich. User net price, $72.00.
666 Variable "D" cardioid
665 Super -cardioid dynamic
655C Dynamic, slim -line
646 Dynamic, lavalier type
635 Dynamic, omnidirectional
$147.00
78.00
120.00
84.00
45.00
ELECTRO -SONIC
Onutidirertionul
Broadcast
-Microphone.
Acclaimed throughout the world for its performance and styling, the ESL -AT2 is unexcelled angpg microphones of its type for
music and"speech. The very small probe di-
:
:
:
:
ESL -ATI,
ESL -MC2,
Probe type, stand mounting $ 80.00
63.00
Suoer- rugged dynamic
ESL- SC403,
ESL -NC2,
Cardioid
Noise cancelling
25.50
4 3.7
5
GOTHAM AUDIO SALES
Miniature Condenser Microphone Systems.
The Neumann KM -54a is a cardioid microphone in a miniaturized package, delivering
the same excellent performance as the Neumann Studio Standard U -47. Designed, with
TV and film in mind, it provides more than
M49d Variable Direction
Condenser Microphone
Z-2t Overload Protector. This is a % -in.
switch section inserted between the microphone capsule plug-in head and the amplifier
section of the microphone. Three -position ring
switch allows straight- through connection, or
gain reductions of 10 and 18 db. User net
price, $36.00.
U47/U48a (Studio) condenser
M49b Condenser, variable direction
KM56 Condenser, miniature
SM2, Stereo condenser, miniature ...
AUDIO
76
www.americanradiohistory.com
AmericanRadioHistory.Com
e
,
$365.00
495.00
440.00
815.00
SEPTEMBER, 1959
New H.H. Scott
Stereo Amplifier has
RESLO
Sludio Ribbon Microphone. Small and attractively styled, he {eslo "Celeste" microphone has an on-off switch built into the base
w1Lil1 adds greatly to its usefulness when
intermittent operation is desired. Another
operatbum! feature of interest is the ability
of the unit to have its response eharacterist es changed by
the user in a matter of minutes. With each microphone are furnished
two pieces of felt and a piece of varnished
cambric. 'l'Imse arc designed to fit into the
1
t
features never before
offered at $139095'
i
rear protective shell. For bass reduction, one
felt is placed in the shell; for base reduction
with rear discrimination, one felt and the
varnished cambric are used; for close talking
use, :t Celt, the cambric, and the second felt
are placed in the shell. Additional operating
fiexihitil
k achieved through variable output impedance. Anyone who needs n microphon for both high and low impedance will
find the Reslo units provide an excellent
answer.
The new H.H. Scott 24 watt stereophonic amplifier, Model 222,
puts top quality within the reach of all. This new amplifier has many
features never before available for less than $200. It is backed by
H.H. Scott's fine reputation. Check the features below- and you'll
see why you should build your new stereo system around the
H.H. Scott Model 222.
CITA tt ALTI:ICI STICS
Frequency range 20 to 15,000 cps.
Patttern
liidirect ional.
Output level : -bS db.
Output impedance
Switchable -low
Equalization switch lets
you
:
:
ohms) /high.
:
(50
choose
between
RIAA compensation for
monophonic and stereo
records; NARTB, for
tape
16
price, $69.95 to 74.95, depending on impedance.
Symphony, RBL /T, low Z
$ 59.50
Symphony, RBM /T, medium Z
64.50
Symphonny, RBH /T, low and high Z
64.50
Avon cardioid, CRL, low Z
79.95
Avon cardioid, CRM, medium Z
84.95
Avon cardioid, CRH, low and high Z
84.95
Any pair factory matched for stereo is available
at $5.00 above the combined price.
SHURE
St dio Ribbon 11icrophone. 'l'he Shure
Yodel 3 :33 is engineered for the most exacting
professional requiretncuts.
is well suited
for motion- picture studios Ty and radio
statins, and professional recording studios.
The 333 is super- cardioid, unidirectional-reduces the pickup of random -noise energy by
73 per cent. It features the patented Shure
"Un iphase" acoustical network system.
in room acoustics and
different speaker sys-
Effective scratch filter
improves performance
on older worn records
and improves recep-
tion on noisy
broadcasts.
Special switch positions for accurate balancing,
for playing
stereo. reverse stereo
and for using monophonic records with
your stereo pickup.
This position lets you
play a monophonic
source such as an FM
tuner or a tape recorder through both
power stages and
speakers.
CHARACTERISTICS
uniformity guaranteed to +!.6 clic.
i'nidirect bunt I. response at
down 12 to 20 tlb f70111 front.
Pattern
:
rear
Impedance: Variable- ín. 150, and 250 ohms.
Output -60 db at 50 ohms; -59 clic at 150
:
and 250 ohms.
Non- reflecting
Finish
:
with aluntinton grill.
AUDIO
''Bronze- Tone"
SEPTEMBER, 1959
case
Channel balance con-
Master volume control
adjusts volume of both
Channels simultaneously. Also functions as
trol adjusts for different speaker efficiencies and brings
channel volumes into
balance quickly and
easily.
automatic
loudness
control whenever desired.
Exclusive center channel output lets you
use your present amplifier for 3- channel
stereo or for driving
extension speakers.
Separate stereo taperecorder outputs.
SPECIFICATIONS: Dual 12 watt channels ; 0.3% IM dis20 to 30,000 cps; extremely low hum level
80db): DC operated preamplifiers heaters; Inputs for
stereo or monophonic recorders, tuners, phono cartridges and tape heads.
Phono sensitivity 3 mn. Sub -sonic rumble filter prevents overload from noisy
changers or turntables.
Price $139.95*
tortion; 0.8% harmonic distortion; frequency response
(-
H.H. SCOTT INC.
Dept. A -5, 111 Powdermill Road, Maynard, Mass.
Export: Telesco International Corp., 36
Insist on genuine H.
It.
Frequency rame: 30 to 15,I100 cps production
radio
tems.
Ercona
Corporation (Electronics Division),
W. 46th St., New York 36, A.S. User net
Separate Bass and
Treble
controls
on
each channel let you
adjust for differences
H.
W. 40th St., N.Y.C.
Scott components.
*{Vest of Rockies $1.43.25. Accessory case extra.
SEND NOW FOR
FREE HI -FI GUIDE
Rush me complete details on your new Model 222 and
your complete 1959 Hi Fi Guide and Catalog. Dept. A -9
AND CATALOG
Name
Address
City
State
kr,///
STEREO
THE SOUND THAT OUTMODES
CONVENTIONAL STEREO!
Cable connector Cannon XL-3-11.
Shock Mount Special vibration isolation unit
of live rubber construction.
Switch Voice -music switch to adjust frequency characteristics for optimum per:
:
:
formance.
7- 9/32" h x
Dimensions
-user net price, $250.00.
:
1- 7/32" w x 1T/s" d.
"Slendyne" Dynamic Microphone. Developed for studio use, the Model 525 is custom built to provide broadcast quality of reproduction. It is exceptionally versatile, and is
entirely reliable for both indoor and outdoor
application. It may be used on a conventional
floor or desk stand. in the hand, or with
lavalier cord and belt clip assembly. The use
of high -efficiency magnetic materials and specially- designed magnetic circuits have made
it possible to develop this small microphone,
at the same time achieving performance
standards usually expected only in larger
models. The 525 is ruggedly built to withstand hard usage and is not affected by normal temperature and humidity variations.
It took the engineering know -how of Weathers to discover this revolutionary
electronic advancement in sound and size! TrioPhonic Stereo introduces the
listener for the first time to "Equalized Sound." Now you can sit anywhere in
the room and experience the same magnificent tonal realism and fidelity of
full -range stereo. " Equálized Sound" is produced by two book -size full range
stereo speakers and a unique, non -directional hideaway bass.
Ask your dealer today for a demonstration of Weathers startling new audio
dimension -TRIOPHONIC STEREO with "Equalized Sound." You must see it,
hear it, compare it, to believe it!
For the ultimate in TrioPhonic stereo listening, select the matched Weathers
synchronous turntable with StereoRamic pickup system.
For more information of TrioPhonic Stereo write for FREE booklet, Dept. -1 t7)
WEATHERS INDUSTRIES, 66 E. Gloucester Pike, Barrington, N.J.
Division of Advance Industries, Inc.
Export: Joseph Plasencia, Inc., 401 Broadway, New York 13, N. Y.
CHARACTERISTICS
Frequency range 40 to 15,000 cps, production uniformity guaranteed to ± 2.5 db.
Pattern : Omnidirectional.
Impedance Equipped with a multi -impedance
switch, furnishing a choice of 30 -50, 150,
:
:
and 250 ohms.
Output -61 db at all impedances.
Finish Non -reflecting "Bronze- Tone" enamel
with beige aluminum grill.
Cable connector Cannon SL -3 -11.
Dimensions : 3- 17/32" 1 x 1" d.
Net weight 14 lb.
User net price, $120.00.
Shure Brothers. Inc.. 222 Hartrey Ave.,
Evanston. Ill.
:
:
:
:
SONY
Variable- Direetiovnl- thlttern Condenser Microphone. The Sony '37A is designed for pro-
fessional recording and broadcast application
where utmost performance, dependability. and
AUDIO
78
www.americanradiohistory.com
AmericanRadioHistory.Com
e
SEPTEMBER, 1959
save on everything in
see the best values in the
196 0
fidelity are essential. Frequency response is
stated to be entirely free of resonant peaks
and dips within the specified range of 20 to
78,000 cps. The C -37.A is operated in conjunction with the Model CP -2 power supply
unit. This power supply incorporates a variable switch permitting three different frequency characteristics for complete versatility in any acoustic surroundings. A small
screw switch on the back of the microphone
housing offers a choice of uni- directional
cardiold pattern, or conventional omnidirectional pattern. !Microphone and power supply
may be separated by as much as 240 feet without affecting performance characteristics.
CHARACTNRISTICS
Frequency response 20 to 18,000 cps + 2.0
db.
Pattern Choice of cardioid or mnidirectional.
Output level omnidirectional. -72 db cardi:
:
:
oid,
:
7o db.
Impedance 2(11) ohms.
Finish Gray with satin chrome.
Dimensions
7- 71/16" x 1-13/16"d.
with
cradle.
Weight Microphone, 1 lb, Power supply. 6
:
:
:
1
:
lbs.
User net price. (' -37:1 system complete including- power Supply, $3:15.1111.
Superscope. Inc., --Audio Iaectrnnics I)icisinn.
Sun Valley, Calif.
TELADI
Variable- Ilirertioaal- l'affrrn Condenser Ili erophone. Imported from I;erm,my. the Model
K -125 nricropbone will meet every requirement of the most denuuul'.n¢ application. It is
imported into We United? States by Durant
Sound Equipment Co.. SO \v. 55th St., tiew
York 19, N.Y.
CIIARACTEItl S'l'ICS
Frequency range 30 to 18,000 cps + 3 db.
I'attern: Switchable. Either non -directional
or cardioid.
Impedance Either 200 ohms balanced or
10,000 ohms unbabnued.
Harmonic distortion Less than 1.11 per cent.
Dimension:: 151_"
\ \'eight
111.4 o ?s.
send for it
WORLD'S LARGEST SELECTION
Here is your complete moneysaving guide to everything in hi -fi,
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budget. For everything in Hi -Fi,
for everything in Electronics,
get the 1960 ALLIED Catalog.
It's FREE -write for it today.
ALLIED EXCLUSIVES:
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components are truly "Honored for
Value" -equal to the very finest in
quality and performance, yet far
lower in Cost. KNIGHT hi -fi
components are exclusive
Allied products.
:
:
:
I
:
l' sir net price. $225.00.
ALLIED
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Build- Your -Own knight- kits -save
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RADIO
sv(vrwwo
ELECTRONICS
i
196Ô
a x
39", .
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ALLIED
RADIO free
CATALOG
ALLIED RADIO, Dept. 1749
100 N. Western Ave., Chicago 80, III.
Send FREE 1960 ALLIED Catalog.
AUDIO
SEPTEMBER, 1959
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MISCELLANEOUS
BOGEN- PRESTO
Jlixer- Preamplifier. Ideally suited
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AUDIO
80
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
RECORDS
(fr,
1ru<°
e;
b',
It's becoming clearer all the time that the
Baroque movement in music was very largely
preoccupied with exotic and interesting tone
colors, odd "combos,- intriguing transcriptions
(such as Each's organ transcriptions of orchestral concerti and his frequent transfer of
choral works to instruments and vice versa, as
well as sacred music into secular. or the opposite). Before we began to restore the original instruments to their pevtpet places in this
older music. we could s ucely understand the
extent of this interest in tonal oddities. Now
that the violas da gamba, the baroque-style
organs, the harpsichords, recorders, high
trumpets, and what not are widely accepted
and enjoyed, we h:nr begun to go further and
uncover dozens-hundreds-of odd work that
previously would have Been ignored as obsolete
freaks, or at best transcribed into sumo con
vention:tl nutdern furnt:It. Nine, we enjoy- them
for their own high coloration and we feel towards them much as their original listeners
did. Interesting change of attitude on our
part.
So --this Rosetti and Dittersdorf disc, among
dozens and dozens. Rosetti is a "new" rediscovered composer who is actually German he
took an Italian name when that was the popular thing to do. I find this particular opus for
two horns not particularly exciting; it is
musically insipid, just pleasant, without bite.
Sure, horns were limited in scope and relatively clumsy then, but that's not the reason
here -look what J. S. Itaclt did even earlier
with horns, as in his Brandenburg Concerto
#1. Rosetti just doesn't use enough harmonic
salt, at least for my ears.
Dittersdorf is better. He has been around in
a small way all along; he is of the MozartHaydn era and writes a fluent and expressive
sort of music, light but relatively substantial.
The preposterous combination of viola and
string bass works out surprisingly well in his
hands. Tho bass does all sorts of pleasant
gymnastics, dotu in the neuter regions, such
as you wouldn't have thought possible; the
viola is the one that gets buried, thanks to a
lot of doubling of its melodies by the higher
orchestral violins for brightness. The viola
always scents :u get into this sort of fix -it's
neither high enough nor low enough to stand
out on its Ovil, along with other solo instru-
-
;
men t s.
Bach on the Biggest. Robert Elmore, At-
lantic City Convention Hall organ.
Mercury SR 90127 stereo
Biggest organ in the world with some thousands of stops and the power of twenty -eight
brass bands (it says here)
and, as you may
guess, old mane Bach on this machine sounds
pretty puny unless you jack up your volume to
size. Musically there is no point whatsoever to
this experiment but music isn't all that is involved: if you want simply to hear this monster well controlled, if you'd like to hear how
Mercury manages to cut through a prodigious
reverberation via stereo (this being one of
stereo's abilities) then you'll enjoy the noise.
There's the Toccata and Fugue in D Minor
of course; also a brace of less familiar items,
Including a whole sWe dovoted to the Toccata.
Adagio, and Fugue in t', an ambitious work for
any convention hall organ, to put it mildly'
,
-
Bach: Complete Organ Works. Toccata
and Fugue in D Minor, Passacaglia and
Fugue in C Minor, Prelude and Fugue in
A Minor, E Minor. Carl Weinrich, Organ
of Varfrukyrka.
Westminster WST 14043 stereo
I'll get in a mention every so often of this
Westminster series, which gees on towards
infinity (in effect)) and probably won't get
there soon. This one was instructive for me by
change-I happened to play it in an extremely
live listening place and found that the characteristic VV'estminster ultra -close pickup, via
numerous mikes, made an excellent effect in
such a room. Might have guessed the same
but then, one doesn't think of such matters
-
AUDIO
SEPTEMBER, 1959
you never
heard it so good...
The microphone can make or break a sound
system or recording set -up
and it takes
a GOOD microphone to pick up every bit cf the
sound, without hiss, hum, or howl. The
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unless they are brought forcibly to attention.
In a normal living room, Weinrich's records
will sound steam -calliope -ish, with too much
hiss and edge and mechanics, not enough sense
of spatial realism. In a live room. the sound is
clear and natural. the room liveness compensating for the "super-hi-fi" dryness of the original ntiking.
This disc, as you'll note, has a group of Bach
king p -n pieces on it : if the complete works are
to be issued. Westminster had better space out
these well known items to butter up the hundreds of less-well-known ones It's always a
problem how to issue a series of this sort. Put
the big drawing cards out first, to catch the
audience, then hope for a follow -up interest
when the less familiar works appear on succeeding discs? A problem, any way you do it.
Whatever the order of issue is, you'll find
Weinrich an efiic:ent. rather hard Bach player,
who ploughs straight ahead without much
poetry. For my ear. his playing is often on the
mechanical side, too much of it just notes
played mostly in time. On the organ, the most
mechanical of all instruments, phrasing and
shaping of the musical lines is all-importantif we are to hear a human being playing music
by another human being.
!
2. CLASSICS
Franck: Symphony in D Minor. Orch. Nat.
de la Radiodiffusion Francaise, Beec am.
Capitol -EMI
G 157
At the age of fifteen 1 fell for this sym hony
like a ton of bricks
seemed the ac e of
modernity to my slightly naive ear. I I'm
right, it was Stokowski's all -out sch naltz
that did the trick, on one of those sensa ional
early 78 -rpm albums. Nobody in his righ ears
would call the music modern today a d it
doesn't lend itself to the all-out trea ur ent
any more either : Beecham's emphasis s on
businesslike clarity, at a fairly rapid mpo
throughout (especially in the middle uovement, which used to move at a Rom: ntic
snail's pace).
Beecham makes a point of recording F ench
music with a French orchestra (see als his
"Fantastic Symphony" on this label) and this
at least guarantees that present-day F eneh
standards of performance will apply to this
very French Romantic music. I don't thin the
French players themselves are any closer to
-it
'
Audiotape "speaks for itself" in a spectacular recording
-available in
a money- saving offer you can't
afford to miss!
this sort of expression today than. say. Sir
Thomas' own home British orchestra but the
characteristic French instrumental tone color
is another matter here, of course. there has
been relatively little change. Slightly nasal,
rather prominent woodwinds, hoarse, wobbly
French horns, a generally bright. brittle sound
-these are proper for Franck and evident in
this recording.
:
Tchaikowsky: Ballet Suites (Swan Lake;
Sleeping Beauty). Virtuoso Symphony of
London, Winograd.
Audio Fidelity FCS 50010 stereo
Sorry. this item again rubs me somewhat the
wrong way, as have its predecessors in the
"First Component" series -but you may well
feel differently and so I'll explain myself.
The trouble here-for me-is mainly technical. The playing is not exactly incandescent
and I don't think either the instrumentalists
nor the conductor felt this was an earth -shaking opportunity to overwhelm their listeners.
But the music will pass -it's OK. What I
don't like is simply the hi fi, because it intrudes.
The records are clearly made for maximum
hi fi effect in the microphoning, and in the cutting, which covers a huge dynamic range. From
an engineering viewpoint this is fine and a
good accomplishment, assuming no distortion
in the cut itself. But in practice, two things
annoy. First, all but the fanciest systems are
going to run into unnecessary trouble reproducing the extremely loud passages here. If nothing else, then sheer needle talk is likely to
bother your listening in some cases, so great is
the intensity. More serious tracking trouble is
obviously likely on many machines. Secondly,
the ultra -wide dynamic range is not a musical
advantage in ternis of home listening.
What? It's not an advantage because though
it may cone nearer to the actual dynamic
range of an orchestra in a concert hall, the
home living room is not a concert hall and
never will be, nor is the home listening situation at all comparable to the concert situation.
Thus I found that no sooner did I turn the
volume up on this record than a passage came
along that blasted me out of my seat-too
loud for comfort. Then when I turned the
music down a bit, came a soft passage where
the music-thanks to the usual incidental
background noise in the normal home-just
vanished into the mud. I came out running
and turned it up again, only to be ploughed
down by the next blast.
The plain fact is that a somewhat restricted
dynamic range, as of the original, is highly
desirable in a great deal of recorded music, particularly that of the 19th century with its
huge dynamic contrasts. This is part of hi fi
thnking and it should be a part -is a part -of
any over-all plan for record production. You
might as well take advantage of a "weakness"
in the system when you can
Natch, if you appreciate top-quality heavy groove cutting and want plenty of whomp,
you'll enjoy this disc and others in the series.
Help yourself. by all means.
!
DETAILS OF THE PROGRAM
The program includes these
colorful selections:
Tschaikowsky
Sibelius
de Falla
Brahms
Russian Dance
from Finlandia
Dance of Terror,
Ritual Fire Dance
(El Amor Brujo)
from Symphony No.
4 in E Minor
Khatchaturian
Stravinsky
Saber Dance
Infernal Dance,
Finale (Firebird
Beethoven
Ode to Joy
Suite)
(Symphony No.
in
D
9
Minor)
DETAILS OF THE OFFER
This exciting recording is
available in a special bonus
package at all Audiotape dealers. The package contains a
1200 -foot reel of standard
Audiotape (an 11/2-mil plastic
base) and the valuable "Blood
and Thunder Classics" program (professionally recorded
on standard Audiotape). For
the entire package, you pay
only the price of two boxes of
standard Audiotape, plus $1.
HERE'S a reel of musical excitement that
belongs on every tape recorder. "Blood
and Thunder Classics" is a program of
great passages of fine music, specially
selected to show you how vibrant and colo'ful music can be when it is recorded on
Audiotape.
"Blood and Thunder Classics" is available RIGHT NOW from Audiotape dealers
everywhere. (And only from Audiotape
dealers.) Ask to hear a portion of the pr
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this unusual opportunity.
nAU MA.
AUDIO DEVICES, INC., 444 Madison Ave.. N.Y. 22, N.Y.
In Hollywood: 840 N. Fairfax Ave.
In Chicago: 5428 N. Milwaukee A e.)
Strauss: Le Bourgeois Gentilhomme
Suite; Intermezzo Waltz Scene. Philharmania Orch., Sawallisch.
Angel 535646 stereo
Old Sirauss's reputation is still on the move
changes almost daily as we ourselves
move away from his times. Not so far back,
his very early tone poems were high- modern,
his first operas were fine stuff-and everything after about 1912 was just so much bunk
and repetition. (Ile went right on composing
until the end of the Second war.) Lately,
we've been discovering his very late works
with surprise and quite a bit of pleasure ; but
the middle- period ones now seem to get more
saccharine and overblown, more out of style,
each year. So it is, for my current ear, with
this music.
The "Bourgeois Gentilhomme" suite, after
Lully of the 17th century, is less pleasant each
time I hear it : the music is pseudo- classical
in somewhat the manner as Kreisler's little
tid -bits, but enormously bloated-an unctuous
"antique" treatment, looking down on the old
music as something quaint and musty, "modernizing" its style into grossly overblown
Romanticism. It doesn't go down well today,
R.
-it
AUDIO
82
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
what
teilh
eXirusive presoni revival of
Ile
luaolities of this older music in its own
terms and tvi1il iIs oevn dignity.
Actually, the old-music kick is merely an
overlay in this Strauss
at be ignored.
\Vital remains, then, is an over -lush, self
cntscious self imitation. witty music that is
just too puffed up to be witty, brief music that
is too bloated to be brief. Give me IIavel.
Debussy, even 11rspighi any day in their var:ous
little., suites -but then. they weren't
German.
Later on. Strauss developed it kind of late
modesty. :t less self -conscious, more sincere
style that is increasingly evident in his later
works- though they tend to get no shorter: he
wasn't modest in the time-sense. His idiom
gets progressively more conservative for the
casual ear; but actually. it Ii.eoutes more refined. more concentrated. simpler and. in the
end, more truly musical. The Last Five Songs.
as they are called, from the late v:n' years
just before lie died, are masterpieces of melodic and harmonic writing.
S)-to end this side -amble- you'll find this
Suite perhaps too sweet, overstutTed, plastered
witli irk. Nice for awhile. but indigestible. The
wahz, from an opera of the twenties, "Intermezzo, is still in somewhat the saute idiom.
though the absence here of the vocal parts
does Strauss all injustice-his operatic voice
lines are the crowning glory of his later work.
vast
-it
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Sept. 11- 13- Houston, Texas, Shamrock
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Sept. 18 -20-Chicago, 8th Annual High
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Sept.
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Sept. 25 -37- Rochester, N. Y., Sheraton
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Oct. 5-111 -New York, High Fidelity Music
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Presented by the Institute of High Fidelity Manufacturers with "Decorate
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Oct. l5 -18-Kansas City, Mo., Hotel Belle rive. (Hi -Fi .lIt.sic Guild of Greater
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D Complete performance data, specifications and price list of the Isophon 4 -way speaker systems.
Name and address of my nearest Isophon dealer.
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AUDIO
Computer by 1.B.ó1./4 -way speaker system
SEPTEMBER, 1959
Atldress
City
Zone
State
83
GRADO
Attcho 61gin,eering
Soci4
ELEVENTH ANNUAL CONVENTION
Following is
...
sented
complete list of papers to be pretechnical sessions.
takes pride in announcing
a new Custom Series Stereo
Monday, October 5.
9:30 a.m. STUDIO AND SPEECH INPUT
Cartridge. The Grado "Custom" was designed for the
selective audiophile who desires excellent reproduction
at a moderate cost. With its
excellent tracking ability and
extremely low distortion, the
new Custom Stereo Cartridge
becomes a perfect companion to the widely acclaimed
Grado "Master' Stereo Cartridge. Because of small moving masses and low tracking
forces, stylus wear is virtually
nonexistent. Grado Laboratories now guarantees all of
the stereo diamond stylii for
a period of 5 years from date
of manufacture.
A grecdy improved Grado
Tone Arm is now available. It
is dynamically balanced and
features a new micrometer
SYSTEMS
Philip C. Erhorn, Audiofax, Inc., Chairman.
A Modern Stereo Recording Console
William Putnam, United Recordin Corp.
A Flexible Combination 3- Channe1
Stereo Microphone and Re-re rding
Console.
Philip C. Erhorn, Audiofax, Inc.
A. New Cardiod -Line Microphone.
Robert C. Ramsey, Electro- Voice, Inc.
od
The Design and Use of a Double C
Stereophonic Microphone.
,
Ltd.
Electric
Co
Northern
A. Jamroz,
Modular Design Techniques Appli to a
Multi- Channel Recording Room Rack
Facility.
John H. Beaumont and Jack A. =: yant,
Vanguard Recording Society, In
UDIO
1:30 p.m. THE TRANSISTOR IN
CIRCUIT APPLICATIONS
Paul A. Grace, Raytheon Manufac uring
Co., Chairman
eriess
A Signal-Biasing Output- Tranfo
Transistor Power Amplifier.
Richard C. Heyser, California In titute
of Technology.
Transistor A.C. Amplifier with High Input
Impedance: A Survey.
John A. Ekiss, Lansdale Tube Co , Div.
of Philco Corp.
nPractical Transformerless Comp
tary- Symmetry Audio Output Amp ers.
W. F. Palmer. and W. Finneault, ylvania Electric Products Co., Inc.
The Design of a Power Amplifier E ployrs.
ing Diffused Alloy Power Trans
Hyman Newman, Bendix Aviation Corp.
Cascade Complementary Amplifier. ElecH. C. Lin and B. H. White, CBS
Ironies.
Transistor Noise at Low Frequenci MacHerbert F. Starke and John S.
Dougall, Raytheon Company.
tracking force adjustment.
Stylus force accuracy of
7:30 p.m. MUSIC AND ELECTRON CS
Prof. Vladimir Ussachevsky, Col :mbia
University, Chairman.
The Problem of Sound Shaping.
Dr. Hugh Le Caine, National Re-earch
Council of Canada.
ant.
The Computer as a Musical Inst
Dr. John Pierce, Bell Telephone Laboratories.
Some of the Specialized Equipment eveloped in Electronic Music Studios.
Prof. Vladimir Ussachevsky, Col mbia
University.
an
Electronic Non -Music-Problems
Orphan Art.
Louis and Bebbe Barron.
tenths of grams may now be
achieved with complete simplicity. Also new is a stainless
steel arm rest lock. All present
Grado Tone Arms can be
modified.
Master Stereo Cartridge
$49.50
. $32.50
Custom Stereo Cartridge
Micrometer Stereo Tone Arm $29.95
.
.
.
.
Tuesday, October 6.
9:30 a.m. MEASUREMENTS AND STANDARDS IN AUDIO
Sheldon I. Wilpon, N. Y.
yards, Chairman.
For
a
at the fourteen
further details write to:
GRADO LABORATORIES,
4614 7th
A enue
ExportSimontrice,
INC.
Brooklyn 20, New York
25
Warren St., N.Y.
C.
Naval Ship-
New Concepts in Audio Testing and I valu atdon.
Felix R. Bremy, American Audi Institute.
on
The Effect of A. C. Bias Wavefor
Harmonic Distortion in Magnetic Tape
Recording.
Robert P. Schroeder, American osch
Arma Corp.
the
Audio Frequency Measurements
Missile Age.
C. E. White, AVCO.
A Suggested Method for Measuring Tape
Modulation Noise.
James J. Davidson, RCA Radio & Vic troja Div.
c
Pine Resolution Simultaneous Pano
Analysis.
Robert I. Bernstein, Columbia U iversity and Reinhold Vogel, Federal cien-
tific Corp.
1:30 p.m. DISC RECORDING AND REPRODUCTION (I)
Benjamin B. Bauer, CBS Laboratories,
Chairman.
Effects of Stylus Size and Record Cleaning Techniques on Phonograph Records.
John H. McConnell, Electro -Sonic Laboratories.
The Talking Bock System for the Blind.
Dr. Peter C. Goldmark, CBS Laboratories.
A Pickup for Strictly Compatible Stereo
and Monophonic Performance.
Rene Snepvangers, Fairchild Recording
Equipment, Corp.
A Single Element Ceramic Stereo Pickup.
P. E. Sterner, R. B. Gray, and R. Luzar,
Erie Resistor Corp.
Practical Aspects of Sigh Fidelity Disc
Recording.
Carlos E. R. A. Moura.
7:30 p.m. AUDIO APPLICATIONS (I)
Rein Narma, Fairchild Recording Equipment Corp., Chairman.
A Survey cf Some New Tubes for Audio
Output Applications.
R. E. Moe, General Electric Co.
Instant Audio.
Louis G. MacKenzie, Mackenzie Electronics.
Equalized Stereo Preamplifier for Professional Use.
Erling P. Skov, Fairchild Recording
Equipment Corp.
A Unique Push -Pull Stereo Magnetic Pick
Up.
E. R. Madson, Bang & Olufson, Denmark.
The VU Meter -Victory Over the Uninformed.
Oliver Berliner, LLltrAudio Div., Ober line, Inc.
High Performance All- Transistor Stereo
Preamplifier.
George Young and Sol Heyton, Transis tronics, Inc.
A Compatible Monophonic -Stereophonic
Phonograph System.
Walter L. Welch, New York College of
Forestry.
Wednesday, October 7.
J. M. Hollywood, CBS
Chairman.
9:30 a.m. REVERBERATION
Reverberation Facilities at CBS Radio.
Henry Korkes, CBS Radio.
Synthetic Reverberation.
Harry F. Olson and John C. Bleazey,
RCA Laboratories.
Architectural Acoustics and Recording.
Russell J. Tinkham, Ampex Corp.
Acoustics of Sound Reproduction in the
Nome.
Harry F. Olson and Herbert Belar, RCA
Laboratories.
Room Acoustics and Sound System Design.
David L. Klepper, Bolt, Beranek, and
Newman, Inc.
1:30 p.m. MAGNETIC RECORDING AND
REPRODUCTION (I )
Walter H. Erikson, RCA Laboratories,
Chairman.
Properties of Base Materials Used for the
Manufacture of Magnetic Recording
Tape.
Edward Schmidt, Reeves Soundcraft
Corp.
Quality Control in Magnetic Tape Manufacturing-.
D. Browning, Orradio, Inc.
The Place of Magnetic Tape in the Re-
Recorder System.
William Fink, Orradio, Inc.
The Tape-Head Relationship in Multi Track Recording.
Frazer E. Leslie, Ampex Corp.
The 120 ips Tape Duplicator for Four Track Commercial Stereo Tapes.
R. A. Isberg, Ampex Corp.
AUDIO
84
www.americanradiohistory.com
AmericanRadioHistory.Com
Laboratories,
SEPTEMBER, 1959
7:30 p.m. MAGNETIC RECORDING AND
REPRODUCTION
w" :t!ter
II.
(II)
Erikson, RCA Laboratories,
Chairman.
Full -Track Stereophonic Magnetic Record- Reproduce Head.
William S. Latham, USN Underwater
Sound Laboratory.
The Use of 35-mm. Sprocket -Type Magnetic Film in Recording Phonograph
A
11th ANNUAL
Masters.
John G. Frayne and J. W. Stafford,
Westrex Corp.
Some New Data on Prequency Response
of Magnetic Recorders for Audio.
John McKnight, Ampex Corp.
A New Equalization Characteristic for
Master Tape Reco-avifng.
A. A. Goldberg and Emil L. Torick, CBS
Laboratories.
Visible Magnetic Recordings.
W. P. Guckenlarg, CBS Laboratories.
Magnetic Characteristics of Recording
Tapes and the Mechanism of the Recording Process.
J. G. Woodward and E. Dealla Torre,
RCA Laboratori,s,
CONVENTION AND EXHIBITS
OF THE
AUDIO
Thursday, October 8.
9:30 a.m.
STEREO
(I)
ENGINEERING
R. C. Moyer, RCA Victor Record Div.,
Chairman.
Why Stereo? The Philosophy of Multi Channel Recording of Music.
John G. McKnight, Ampex
Corp.
Status Report of National
Stereophonic
Radio Committee.
charles J. Hirsch, Hazeltine Corp.
Stereophonic A.M. Broadcast
Transmission.
J. M. Hollywood and M. K. Kronenberg,
CBS Laboratories.
Sterephonic Display Patterns.
Benjamin B. Bauer and G. W. Sioles,
CBS Laboratories.
Signal Mutuality and Cross Talk in Two and Three -Track Three -Channel Stereo
Systems.
Paul W. Klipsch, Klipsch & Associates.
SOCIETY
Showing Professional Audio Equipment for Studio
and Laboratory
1:30 to 4 :00 p.m. only. STEREO (II)
R. C. Moyer, RCA Victor Record Div.,
Chairman.
The Subjective System Approach to High -
Quality Home Music and Vocal Reproduction.
H. R. Finney, Radio Frequency Laboratories, Inc.
Perception of the Stereophonic Effect as a
Function of Frequency.
W. H. Beaubien,
Electric Co.
Is Standardization General
of
Procedures Possible? Stereo Recording
Dr. Fritz A. Kutner, Musur,cia Records.
OCTOBER 5th THROUGH
9th
AT THE HOTEL NEW YORKER, 34TH STREET AND
EIGHTH
AVENUE,
NEW
YORK
CITY,
NEW
YORK
6:00 p.m. ELEVENTH ANNUAL BANQUET
Friday, October 9.
9:30 a.m. AUDIO APPLICATIONS (I I
S. Edward Sorensen, Columbia Records,
Chairman.
A Variable Transmission Network for
Audio Signals.
Jacob Klapper and Cyril M. Harris,
Electronic Research
Photo- Sensitive ResistorLaboratories.
in an OverloadPreventing Arrangement.
J. Rodrigues
igues de Miranda, N. F. Philips
Gloeilampenfabrieken, Eiudho -n, Nederla ad.
Techniques in Audio Transformer Design.
W. II. L:rtva11, Essex
Corp.
Design & Development ofWire
an Engineering
Report.
George P. Goodall, Ampex Corp.
SEVENTY PAPERS Studio and Speech Input Systems
Transistor in Audio Circuit Applications
Music and Electronics Measurements and Standards in Audio Disc Recording and Reproduction
Reverberation
Magnetic Recording and Reproduction
Stereo
Audio Applications
Loudspeakers
Symposium on Techniques in Production of Stereo Tape and Discs.
1:30 p.m. LOUDSPEAKERS
Abraham I :. Cohen, Advanced Acoustics
Company, Chairman.
An Unusual Application of a High-Fre-
SESSIONS 9:30 a.m. and 1.30 p.m.
)
quency Unit.
Charles D. Lindridge.
A Modulated Compressed-Air Loudspeaker
for the Reproduction of High -Level
Speech or Noise.
A. L. Witohey, Radio Corporation of
America.
A New High -Frequency Speaker for High Fidelity Systems.
Earl Matsuoka, Uni versity Loudspeakers, Inc.
A Five and One Half Octave Complementary Driver -Network System for Reproduction of High Frequencies.
William H. Thomas, James B. Lansing
Sound, Inc.
New Stereophonic Projection Console.
Benjamin B. Bauer and G. W. Siols,
CBS Laboratories.
7:30 p.m. Symposium on Te:i+ niques in
Production of Stereo Tape and Discs.
AUDIO
+
SEPTEMBER, 1959
Tues.,
Wed.,
Fri.
Annual
daily, also 7:30 p.m. Mon.,
Award Banquet Thurs. evening.
EXHIBITION noon to 6:45 p.m. Mon. through Fri.
(Runs concurrently with IHFM High Fidelity Show)
Program available from
AUDIO ENGINEERING SOCIETY
P.O. Box 12, Old Chelsea Station, New York 11, New York
85
AMPLIFIER
(
Now, because of direct factory representation, it no longer
pays to buy anything but the best...Neumann.
Effective September
U
-47
U -48
1959
1,
-$365
KM -54a
KM -56 -$465
SM -2 -$815
-$435
KM-53a-$415
Of course, unconditionally guaranteed for
1
year.
Gotham Audio Sales Co., Inc.
N. Y. 36, N. Y.
2 West 46 St.
Circle 86A
erally have no advantages while the
potentials of noise introduction are increased. In the schematic, Fig. 2, such
a circuit is employed ; in one channel being variable with six equalizer positions
for use with monophonic records, and
although at least theoretically it should
be duplicated in the other channel (and
may be) for use when the "compatible"
stereo cartridge is employed with monophonic discs, the simple equalizer network for the RIAA curve between the
stages of the second channel preamp, in
practice, was acceptable. Figure 3 is
the basic arrangement of the equalizer
network of this between-the -stages type,
with a table of components to permit
construction of the various equalizer
networks required by one for his particular library of records.
While wirewound resistors are specified at all places where their use will contribute to lowering the noise -occasioned
by the use of a.c. for filament heating,
their values and the values of the bypass
capacitors, more importantly, have been
chosen to provide a very rapid attenuation of all signal below 30 cps without
noticeable effect upon the audio spectrum. Two -watt, or larger, low -noise
carbon resistors may be substituted with
reasonably satisfactory results if the
specified wirewound resistors are unavailable.
The original "expression" circuit designed by Johnson, employed a metal
(A)
EXCELLENT !
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.004
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LON
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0
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820
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Better than
From 21/4" (small size)
to 15" (large size)
MOST
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WOOFER
Cl
CURVE
RIAA
High Quality
for
3 WAYS
(1 5
from page 16)
Explanation Sheets Free
FUKUYO SOUND CO., LTD.
Horifune, Kita -ku, Tokyo
Cable: CORALFUKUYO
25 -2
Circle 86B
AES
.0005
RCA ORTHO
.00075
COL 331/3
.001
COL 78
.001
RCA 78, 45
.0005
www.americanradiohistory.com
AmericanRadioHistory.Com
K
Fig. 3. (A) Basic equalizer network,
(B)
and
component values for various equalization curves.
AUDIO
86
Meg.
SEPTEMBER, 1959
pentode, 6S(7, for the amplifier stage
of the "side" circuit to provide sufficient gain for bias control of the next
tube, after rectification; and a 6SK7 as
the tube for bias control, corresponding
to V1 in the schematic. In selecting this
tube, (iSK7, although very little gain was
needed and the original circuit showed
it to be triode connected, he felt that the
variable mu characteristic of the 6SK7,
due to the peculiar grid construction, was
of advantage for this specific use. In exploring the potentials of Johnson's circuit, and in experimenting for the
adaptation of his basic principles to
problems of balancing the dynamic range
in stereo reproduction, it was found
that the use of it single triode stage in
place of his 6SG7 would, with other
changes in the component values, result
in sufficient gain to provide enough
rectified bias- control voltage for such
requirements, especially since not only
does the circuit provide controllable
amounts of volume expansion, but also
controllable amounts of volume compression-this compression potential heing important foi', strangely, occasionally the disparate erosion of the two
stereo sound producing parts of the recording groove .sconta to result in a
slight increase in the dynamic range of
one channel and a loss in the other.
(This phenomenon occurred in the recordings of only one manufacturer of
the several tested.)
Likewise, for this particular adaptation of the principles of Johnson's "expression" circuit, it was found that a
single triode, such as one section of the
6SL7, having a fixed negative bias of
one volt, was eminently suitable to replace the 6SK7 of his circuit. But for
those who desire greater efficiency from
the bias -control circuit than that afforded by the triode arrangement in the
schematic, it is feasible to employ two
6F7 tubes in place of the twin triodes,
V,1 and
arranged so as to use the
pentode sections for the amplifier in
the bias -control circuit, and the triode
sections for the stage for bias control,
Fiq. 4, with the 6H6's interposed between the two sections of the 6F7. 61.18's
by reason of their cathode -bias characteristic are not suitable for this function,
despite the fact that they consist of a
pentode and a triode in the same envelope.
Generally, however, the use of 6SL7's
for both the side amplifier in the bias control circuit and for the immediately
following stage, will provide sufficient
range of volume expansion and volume
compression for the most exacting needs
of dynamic range balancing, of restoring dynamic range to monophonic discs,
and of correcting dynamic range inequalities. Nevertheless, some who listened critically to the "panphonic" control amplifier, during the developmental
STEREO ON DISPLAY
in your
HIGH FIDELITY
SEPTEMBER, 1959
SHOWS
with the newest and latest in stereo high fidelity
from leading high fidelity manufacturers
Don't miss these public showings
of hi -fi equipment . . from the
most economical units for the
budget - minded to spectacular
home music theaters
compare
and enjoy them all.
.
...
Complete Stereo and Monophonic High Fidelity Systems
- - - - - - -
Amplifiers
Pre-Amplifiers
FM -AM Tuners
Turntables
Record Changers
Phono
Cartridges
Microphones
Music Control Centers
Speakers
Speaker Enclosures
Equipment Cabinets Finished
and Assembled or Do -It -Yourself Kits
THREE FULL DAYS OF CONTINUOUS DEMONSTRATIONS
FRIDAY, SATURDAY, AND SUNDAY
V
AUDIO
city...
FROM
1
P.M. to 10 P.M. FOR EACH SHOW
RICO HIGH FIDELITY MUSIC SHOWS, Fall 1959
Milwaukee
September
11 -12 -13
Pfister Hotel
Rochester, New York
September
25-26-27
Sheraton Hotel
Buffalo, New York
October
Seattle
November 6-7-8
New Washington Hotel
Portland
November
13 -14-15
New Heathman Hotel
Philadelphia
November
20 -21 -22
Benjamin Franklin Hotel
30 -31 -Nov. 1
Statler Hotel
ADMISSION 75t'
RICO ENTERPRISES, INC. 500
N. Dearborn, Chicago 10, III.
87
WHERE
THERE'S
R
A FINE
TAPE
RECORDER...
Ir
h
V.tere's
A
ferro -sheen tape
_
)
}
work, felt that the use of a 6NS7, despite its high fixed grid bias, for V8 produced greater realism and was less critical in operation. Should this tube be preferred in future construction, the values
of
and R25 should be changed to
470 ohms. If miniature tubes are preferred, 12AX7's and 12AU7's can be
substituted for the 6SL7's and 6SN7 respectively without change in component values.
As stated above, the RC values in the
"expression" circuit are such that the
grid bias voltage of V,q follows, more or
less, the average audio levels rather
that the audio itself, but in the "panphonic" control amplifier the time constants are less critical than in the original design. However, even though the
RC values given (for R41, R50, Cs0, Csi,
C25i C26J C28 and C29) have proven suitable for most program material, and
since the usual 10 per cent commercial
components were used, the actual selection of these RC values should be determined by critical listening. R4,--C30
and R5,-C largely determine the attack time of a musical note, and C25-C
in ratio with the center and
tapped pots affect the fall -off time (and
hence is variable, within limits, as opposed to the fixed attack time) ; their
proper value determination, therefore,
although not critical is nonetheless important, and errors in the direction of
prolonging the fall-off time may result
in "cloudied" reproduction, especially
of recordings of large orchestrals, chorals, and so forth, where there must be a
"clean" blending of instruments or
voices. Similarly, errors in the direction
of prolonging the attack time will distort
such instruments as the piano, and other
"plucked-string" instruments, as well as
those of the percussion group.
note to
PENTRON owners
To insure optimum re-
cording quality with
your machine, the
recommended tape
is
irish Long
/
Play #602. send
for technical
bulletin.
C-C
ORR INDUSTRIES
Opelika, Alabama
INC
EXP:458 B'way, N.Y. C. CAN:50 Wingold Ave., Tor.
Circle 88A
Operation
While this control unit may seem to
rather elaborate when compared to
the preamp -control units in most commercially built stereo rigs, its superiority
is ample justification for its construction and use; and even though its control -panel may resemble, in complexity,
that of a broadcast studio, in actual operation it is fairly simple since, in usual
use, only those controls are employed
that are necessary to the operation of
any good quality stereo rig selection of
the proper equalizer position, adjustment of the loudness and of the treble
and bass controls to the acoustics of the
room and to listener preferences. The
expansion- compression controls present
no great difficulty, since their adjustment is dependent upon the degree of
expansion or compression needed or desired, to enhance the "presence" and
realism of spread -sound reproduction
of monophonic program material or to
balance inequalities in dynamic range
be
:
REAFFIRMED ... at the Brussels Exposition ... the
American Exhibition in Moscow ... and two request per-
formances for Bell Telephone Laboratory personnel...
the superiority of KLIPSCH derived three channel stereo
and KLIPSCH speakers in faithful tonality, solidity of sound
curtain, and accurate geometry.
Write for information.
Klipsch and Associates, Inc.
HOPE, ARKANSAS
Circle 88B
AUDIO
88
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
in stereo reproduction. But it must be
borne in mind that too much volume expansion will produce sharp distortions
of the sound peaks, and similarly too
great a degree of compression will, even
when indicated, obliterate the fidelity of
the recording. Properly and judiciously
used, however, in combination, the expansion- compression functions of the
unit will effectively restore the dynamic
range balance with minimum loss of
fidelity, although with very old stereo
dises such must be a compromise.
The inclusion of pot, R,2, to vary the
input resistance load, is of course optional, but the author has found that
sonic means of simple design for varying the loading of magnetic cartridges
is desirable, since a reduction of the
resistance load lowers the rolloff, before
prearuplification, thus reducing surface
noise-at the expense, of course, of
fidelity -of old records, of which there
are ninny that are still worth listening
to. I knee the inclusion of this pot in
the design of the preamp stages is a
practical device for making usable many
pre -hi -fi recordings that are too noisy
for playing on the ultra sensitive equipment of most home music systems.
As designed, this panphonic control
stereo amplifier, while elaborate, will
nevertheless, provide such greatly increased realism to monophonic program
materials and aid in preventing the destruction of presence and realism in
stereo discs as they age with use, by providing a means of maintaining the dynamic range balance of the two channels.
Æ
PARTS LIST
Cl, C5, C6,
C,u C,6,
CP, Cl,
C4, Cs, C,s,
25 µf, 25 y, electrolytic
.05 µ.f, 400 y, paper
CIB
Bó
D
C,,, C,E,
C,S,
C17, C,Y, C,!4,
Ce
0.1
C,6, C6,
C C,
.001
CIS, C41, C4,
C8, Cm, C15,
C16, C18, C6,
C8,
C
C,,,
C44
C,4,
C56
C
C4
C,B, CO,
C45,
Cps, Co, CO, C56
to J,
Ja, J,
R Rs, R R44,
R4:, Rsa,
R R69 R6,
R4, R,4
Reu,
R,,,
Reu,
RIR
R8, Rs,
R,,,
1
watt
watt
watt,
1/,
1
matched
potentiometer, 500 k
ohms, linear taper
ganged potentiometers,
1 meg, audio taper
potentiometer, 50,000
ohms, audio taper
(or 100 k ohms, linear
taper, with 100 k
resistor 1/ -watt
between end taps)
3900 ohms, 1/2 watt
470 ohms, 2 watts,
wirewound
470 ohms, 1/._, watt
1000 ohms, watt,
R
R,o, R,4
R
Rt,
R,4,
1
47,000 ohms,
27,000 ohms,
22,000 ohms,
R,6, R58
R6, R,6
R],
paper
watt
1/2 watt
33,000 ohms, 1 watt
100 k ohms,
220 k ohms,
Rco
R,,,
v,
µf, 450 y, electrolytic
µµf, ceramic
Phono jacks
Closed circuit phone jacks
(optional, see text)
J,
R4
µf, 400
paper
II
STEREOD YME
PHONO PICKUP
10
50
C4,
R5,
y,
.01 µf, 400 y, paper
.02 µf, 400 y, paper
470 µµf, ceramic
.002 µf, ceramic
760 µµf, ceramic
600 µµf, ceramic
C
C,,,
µf, 400
RE6
R,S, R:,, R,,, R,6
R16, R18, R,e
New, hum free push pull magretic stereo pickup of, superb
characteristics. True stereo
reproduction because of wide
channel separation. Smooth
response and light tracking
combine to give clean natural
sound from both stereo and
monophonic
recordiings.
Mounts in all standard arms.
With replaceable diamond
stylus- $29.95* net.
Bó TONE
ARM
1
wirew ouI
Integrated
1
Arm and
Cartridge
MODEL TA -12
1
Combined arm andStereodyne
II Cartridge
for optimum
results. Dynamically balanced,
gimbal- pivoted arm permits
2 gram tracking. Simpd!e to
mount, handsome appearance,
and outstanding in performance. Only $49.95* net.
"Slightly higher in the West
Available from leading high
fidelity dealers everywhere
V8A
?6F7
6F7 HEATERS =1 AND 7
/1
2
6F7
Fig. 4. Modified expression circuit giving slightly different performance.
AUDIO
SEPTEMBER, 1959
DYNACO, INC.
391.6 Powelton Ave., Phila. 4, Pa.
Cable address: Dynaco, Phila., Pa., U.S.A.
89
1800 ohms,
R 17, R
1
watt.
wirewound
New
22,000 ohms,
R,,.
R,:;
R,,.
R43, R5s
1
watt.
22.000 ohms. 1 watt
10,000 ohms, 1 watt
(38 ohms, 1/2 watt
2 -pole, 6 position switch,
R5,
4.7 meg, 1/2 watt
100 k. 1/, watt
510 k ohms, 1/2 wa
potentiometer, 500 k
Rao. R46, R49
R R.;,
S,. S.
F
PROFESSIONAL 55
1
6118
6SL7 (or 12AX7 )
6SN7 (or 12A177)
6H6
V,
centertapped (m.
he
1/2
(Mallory 3126J)
- V.
f -.,, V,;
ohms, linear taper
watt
1
R5
R53, R55
R56, R56
matched
megohm,
R,,;
V6, V,
megohm, see tex
the Ultimate
TEN -WATT AMPLIFIER
STEREO CARTRIDGE
(from page í2)
The low- frequency power handlin; capacity shows up when sharp drum beats
or bass violin pizzicati are passed without amplifier breakup. The high damping
factor, Fig. 5, controls any unw anted
cone movement. Some modern speakers,
however, require lower damping factors
for optimum results. If you are nterested in lowering the damping factor of
the amplifier, remove the connection
from the "0" output terminal (see Fig.
7) to the common secondary lead (which
is left connected to the ground bus and
ground it through a resistor of no more
i
COLUMBIA
1 ohm. The voltage feedback should
now be decreased, by increasing the value
of R, and decreasing the value of
keeping the product of the two constant.
You will have to experiment with different ratios of current and voltage feed hack to get the required value of internal
resistance. In any case, don't use more
than 1 ohm for the current feedback resistor, or too much power will he dissipated in it. Use a two -watt or larger
than
C
resistor.
Figure 6 shows the underside of th(
amplifier. We used an S" ' 12" v 3'
Professional 55 ...
Cost $28.95
This new transparent cartridge is
the professional's version of the
popular Columbia CD. A high -com.
pliance model with excellent transient response, it uses a .5 -mil diamond stylus and is designed for
transcription turntables. Comes
complete with 4 miniaturized plug in equalizing networks for low- and
high -level inputs.
40
20
Fig.
5.
Curve of
damping factor
vs.
frequency.
-o
o
-20
CURVES, FACTS AND FIGURES PROVE IT
10000
700
FREOUENCY IN
CYCLES PER SECOND
Ask for Bulletin E -331. Check the
Professional 55's superiority in:
linearity
separation .. , needle
point impedance
low mass .
freedom from hum and distortion
... output level ...and ruggedness.
...
...
YOUR OWN EARS PROVE IT
Better still. Your own ears will convince you the Professional 55 is
your best investment. Ask to see
and hear it at your distributor's
today!
CBS ELECTRONICS
A Division of
Columbia Broadcasting System, Inc.
Danvers, Massachusetts
Distributed in Canada by
CANADIAN GENERAL ELECTRIC CO., LTD., TORONTO
Fig
6. Under -chassis
view of the amplifier
o
show placement of parts
AUDIO
90
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
INCREASE
R.0 =2.25
TO
6AV6
CATHODE
DECREASE
16
_
to
selcet` i
U,I.t1)Il(l
neµ
R
<I
(2wl
Fig. 7. Detail of changes to output circuit
to lower damping factor.
(
the
tJudiol)llile'!r/
deinl'ndtinñ*
oductlo
u
P
in
stereo reP
1
lnterna t1Onaow
has8 n pf
world,
ergerequirements
turntable
as
hpnOrmodi tot ontill
du
t
your déati°ñ of
in
tO visit
reproduction.
te
precision
stereo
r selection
invite ;o Silent
dePth
your
estic
We cordiallyremarkably
it and majestic
for
intense
meets relproduction ,e,.
stereoo
record
*Obviously
ef eO
chassis, and there is plenty of room underneath it. The balance control is a locking type, to eliminate tampering after
it has been set. The only precatuion to
observe in wiring is to keep heater leads
twisted away from low level audio circuits to eliminate hum. Use direct point to -point wiring throughout, and follow
our layout (Fig. 1) for easiest construction as well as nice overall appearance.
The output tubes are being operated at
very near maximum ratings, so give the
amplifier plenty of room to breathe.
Remember when you use it that this
is a 10 -watt amplifier, and, although it
will outperform many higher powered
amplifiers, it won't drive low -efficiency
loudspeakers in a 20' x 30' living room.
For efficient speakers, however, it can't
he heat.
CONNOISSEUR MODEL B
TRANSCRIPTION TURNTABLE
MADE IN ENGLAND
Be sure and see (and hear) the new
Connoisseur Stereo Arm and Pickup with
sensational features. One demonstration and
you will be convinced.
ERCONA CORPORATION
f
Electronic Division)
16 W. Id Street. Inept 44
New York 36, N. Y.
Circle 91A
JUST WHAT IT TAKES
TO MAKE THE
SHOW...
sow-
PARTS LIST
C,
Cr,
C,
C,,
Cs, Ce, C,
C
C,
I,
7r
L,
R,
Rs
R,
R,
R,
R6
RR R
R,
R,,, R,:, R¡,
R, R
R,s
R
R,Y
T,
µµf, ceramic
µf, 600 y, paper
250 sf, 50 V, electrolytic
20 -40 -30 4f, 450 y,
electrolytic
20 µf, 450 y, electrolytic
.05 µf, 400 y, paper
Phono jack
33
.02
Octal socket
6 -H, 160 -ma filter choke
(Triad C -12A)
68,000 ohms, 1/2 watt, 5'7,
2700 ohms, 1/ watt, 5%
470k ohms, 1/2 watt, 5%
10,000 ohms, 1/2 watt, 5%
470k ohms, 1 w, deposited
carbon
1.0 meg, 1/2 watt, 5%
18,000 ohms, 1 watt, 5%
20,00 -ohm linear potentiometer, (locking, see text)
220k ohms, 1/ watt, 5%
22,000 ohms, 1,4 watt, 5%
250 ohms, 5 w, wirewound
10,000 ohms, 1 w, 5 %n
5600 ohms, i watt, 5%
Power transformer, 550 y,
c.t.,110 ma; 5Vat2a;6.13v,
c.t., 5 a. (Triad R -12A)
Output transformer. Acrosound TO-250
6AV6
6C07
46
ee
-
THE EASY TO READ
EASY TO OPERATE
STUDIOSOUND S -301 -R PROGRAM EQUALIZER
Assure the success of your shows or recording sessions with the always dependable S -301 -R
check these top performance StudioSound specifications:
...
LOW- FREQUENCY EQUALIZATION: 12 db in 2 db steps at 100 cps & 40 cps
(shelving characteristic).
HIGH -FREQUENCY EQUALIZATION: 12 db in 2 db steps at 3, 5, 7, 10 and
15 kc. (shelving characteristic).
HIGH AND LOW FREQUENCY ATTENUATION: 16 db in 2 db steps.
This star performer has built -in flexibility, it's available complete on one panel
or in money saving kit form.
Other fine StudioSound components vital to a good show are: StudioSoun, Filters,
Pads and Networks. Special components made to order. For further information
contact:
STUDIO SUPPLY CO.
711 So. Victory Blvd.
Burbank, California
Box Z -9 -59
G13X7GT
GZ34
AUDIO
SEPTEMBER, 1959
Circle 91B
91
NOW... enjoy your HI-FI OUTDOORS
PATIO, GARDEN, TERRACE, PORCH
AUDIO TECHNIQUES
with the new wT -6
( from
HI-FI
ATLAS
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all- weather construction ... install it, forget it!
or take it with you wherever you listen.
True HIGH FIDELITY TWO -WAY system -not
just a "compromise" of two horns coupled to
a single diaphragm. The WT-6 comprises a
weather-proof cone type driver (with 6 -inch
throat) coupled to its individual woofer horn;
a separate pressure -type driver loaded to its
separate tweeter horn. The built -in crossover
electronic filter supplements the electromechanical frequency- limiting characteristics
of the 2 individual reproducers
providing
the center winding form, as shown in Fig.
3. This will produce fifteen slits in each
side of the winding form.
Take a 14 -inch machine bolt 4 inches
long and slip the three pieces of the winding form onto the bolt. Put strong glue on
...
the contacting surfaces and then tighten
the nut on the bolt until most of the glue
has oozed out. Wipe away any excess and
let the form rest for 24 hours. (Actually,
this resting time will depend upon the type
of glue used. There are some excellent glues
available today which will set in 20 minutes.)
An improvised crank or winding handle
is screwed on temporarily to one of the
unslitted sides. Then the nut is removed
from the bolt and the threaded end of the
bolt is clamped securely in a vise, the body
of the bolt acting as an axle for the winding forni.
1.
-
for smooth frequency division
as each
speaker functions within its engineered
range of frequencies.
All- weather
high efficiency
compact
for all indoor and outdoor uses
universally adjustable "U" -type rugged steel
mounting . . finished in high temperature
baked modern beige enamel.
...
...
.
s
.
page 6)
.
.
net
$34.50
POWER RATING 15 watts continuous
FREQ. RESP. 140- 15,000 cps
245
IMPEDANCE 8 ohms. DISPERSION 120°
DIMENSIONS bell opening 15 ", overall depth 12"
See the WT -6 at your local distributor. Send for catalog
175
210
105
140
A -S
70
ATLAS SOUND
CORP.
St., Brooklyn 18, N. Y.
1449 39th
JJT.J-
TARTING POINT
Fig. 4
BRITISH PRECISION WORKMANSHIP
Guarantees Finest Hi -Fi Reproduction
The secondary is brought out as
four separate sections which may
be connected in series or parallel
to match speaker impedances of
0.95, 3.8, 8.5 and 15 ohms by this
arrangement.
Each hail' primary is brought out
to terminals as separate windings
and is tapped for distributed load
performance.
Latest grain orientated cores.
Fully interleaved.
-
for use in 20 or 35 watt amplifiers
5200 Series
less than 1 %p. Available in 4 models
Tapped at
to Plate Load
Plate
Model
43°ó
9
I2K ohms
P520I
43 °o
9K
ohms
7
P5202
P5203
5
P5204
3
---
7K ohms
5K ohms
-
for use in 35 to 50
5300 Series
less than l °,,.
Plate
to Plate Load
Model
12Kohms
P535I
9K ohms
7
P5352
7K ohms
5
P5353
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3
P5354
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with distortion
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watt amplifiers with distortion
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Tapped at
43 %p
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TO SWITCH
$30.00
NET
Fig. 5
and
Name of Nearest Dealer
TRANSFORMERS
Sole U.S. ReR.
Winding: (Fig. 4). Pull a % -inch length
of the No. 16 enamelled wire through one
of the slits so that it points outward from
the form and label it "starting point".
Start to wind slowly and evenly, meanwhile
counting every turn of the crank handle,
until two layers of 35 turns each have been
completed. At the 70th turn pull the wire
to the outside of the form and slip it
through one of the slits and return it to
the central core through the next slit. Mark
"70" close to the wire on the outside of the
form to know that the exposed piece of
wire is the 70th turn. After another layer
of winding again pull the wire through a
slit and return it to the core via the next
slit. Label close to the wire as "105"; wind
another layer of 35 turns, pull through a
slit and label as 140 -and so on, on both
sides of the form, until 525 turns have been
completed and properly labeled.
M. SWEDGAL 258 Broadway, New York
7,
N.Y.
Circle 92B
When 525 turns have been wound on the
form, wind a few layers of cellulose tape
over the coil, followed by a few layers of
electrical tape. This will afford ample protection to the coil.
AUDIO
92
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
STEREO
ON
DISPLAY
at the
Remove the crank handle from the form
and discard the bolt. Using a file or sandpaper, remove the enamel from the exposed
lengths of wire on the sides of the form,
taking care not to remove the numbers
written on the form.
Mount the coil to a suitable base with
the unslitted sides screwed to it.
Solder a piece of wire to each of these
fifteen taps and connect them to the multi contact switch and label every contact
position with the number of turns it represents.
Testing. The variable inductance thus
made must be manipulated from the outside of the loudspeaker enclosure. The connecting lampcord is passed through the
cabinet back and the back- screwed on,
with no screws left out. A suitable hank
of capacitors which can be varied from 1 to
50 of (surplus bathtubs) are introduced
into the circuit if the network calls for
them. Then the testing continues along
conventional lines with audio generator,
etc., but plain aural judging is also a lot
of fun and highly illuminating. Once
a proper value of inductance determined
by the number of turns, is ascertained a
new and smaller coil can be wound and put
permanently into the enclosure or better
still, fastened to the back of the cabinet.
I matched a motley crew of nine speakers: three 15 -inch woofers, two 10 -inch
middlers, four 4 -inch tweeters -to two
homemade cabinets, using this variable
inductance and a number of capacitors in
a quarter section network, with very gratifying results.
.
Detroit Third Annual
HIGH
FIDELITY
SHOW
THREE FULL DAYS
CONTINUOUS
DEMONSTRATIONS
OF
STATLER HOTEL
FRIDAY, SATURDAY,
AND SUNDAY,
OCTOBER 16 -17 -18
FROM
P.M. to 10 P.M.
1
ADMISSION 75c
the newest and latest in stereo
high fidelity from leading
high fidelity manufacturers
Don't miss this exhibit of hi -fi equipment
from the
most economical
units for the budget minded to spectacu.
.
.
lar home music theaters ... compare and
enjoy them all.
- - -- -
Amplifiers
Pre -Amplifiers
FM-AM Tuners
Turntables
Record Changers
Phono Cartridges
Microphones
Music
Control Centers
Speakers
Speaker Enclosures
Equipment Cabinets
Finished and
Assembled or Do -It- Yourself Kits
AUDIO
SUND
HAPPY?
To achieve superlative sound reproduction,
there must be a reason. Such results cannot
he obtained from cheap materials, slipshod
.workmanship, expedient design. or other cost
ratting devices to make a big. wide profit.
The (takers Ultra 12 Loudspeaker and the
ltradford Patented Baffle reproduce ultimate
facsimile for an inevitable reason. The reason
is in the specs.
BAKERS
ULTRA 12
to 25.000 cycles
a single, exponential 12" cone;
20 cycle cone resonance; 18,000 gauss;
20
from
Turns
70
105
140
175
Inductance
Turns
0.1 Mh.
315
350
385
420
455
490
525
0.2
0.3
0.5
0.7
plastic
round;
210
245
280
1.0
1.4
1.8 Mh.
4.5
5.4
6.2
This material was submitted by
Louis Julius Côté, Ottawa, Canada.
Dr.
Æ
AUDIOMAN?
the October issue
(from page 24)
plemented with, "The sale of a component of a patented machine, etc., must
constitute a material part of the invention and must be known to be especially
made or especially adapted for use in
the infringement before there can be
contributory infringement. And likewise the sale of staple articles of commerce suitable for noninfringing use,
SEPTEMBER, 1959
sur-
aluminum
cast
aluminum
trame; 20 watts; no distortional crossovers.
For these reasons, the Bakers Ultra 12 is
extremely sensitive, and therefore provides is
smoothness, clarity and transient response...
t true naturalness ... not found in any other
speaker regardless of price. Pride of posses .ion is only 85 bucks.
BRADFORD
PATENTED BAFFLE
Stereo, or monaural, the trend is toward
compactness; 12" x 12" x 9" for Ss and 10s;
17" x l7" x 14" for 12s and 15s. Because of
the patented (No. 2,834.423) pressure relief
valve, this enclosure is equivalent in results
to a 20 cubit foot
Infinite baffle.
The Bradford
Who's the first
See
foam
voice coil on aluminum former; heavy
Inductance
2.3
2.9
3.4
maxwells;
200.000
APPROXIMATE INDUCTANCE VALUES
PATENTS
Complete Stereo and Monophonic High Fidelity Systems
ARE YOU
Patented
Baffle
provides the only
true acoustic sus-
principle
for the pressure
relief valve automatically regupension
lates the acoustic
tension or spring
of the air within
the enclosure to
the excursion characteristics of the Bakers,
or any other, speaker. Because of thin patented principle, there is absolutely no boom,
cabinet resonance or listening fatigue.
The Bradford Patented Baffle is recommended by renowned audio authorities, and
mold throughout the world because of its outstanding merit and adherence to claims.
Mahogany. walnut and unfinished birch;
selected, grain -matched. e1 plywood veneer;
rugged construction; hot lacquer finish . . .
hand -rubbed. $34.60 to $A9.90.
Speakers and baffles sold separately. In
combination, we guaranty these units to be
superior in true realism to any other system
regardless of price.
write for literature
BRADFORD AUDIO CORP.
27 East 38th St., New York f6, N. Y.
Telephone: OXford 7 -0523
93
www.americanradiohistory.com
AmericanRadioHistory.Com
does not
constitute contributo
in-
fringement "5
Shortly after this statute becam effective a suit was brought agains the
Union Carbide and Carbon Corpor.tion,
the Radio Corporation of America and
others. There it was charged that " nion
inCarbide and Carbon Corporatio
tending to bring about infringeme t of
plaintiff's patent, secured from pl ntiff
and passed on to the other defen ants
confidential information making infringement possible. ""
The Union Carbide Corporation contended that there was no ground f .: the
charge of contributory infringe nent,
since under this statute it is re ired
now that there be a sale of a component
part of the patented device to cons itute
a violation of the patent law.
In its consideration of the re: uirements of the present statute the Federal
court said that it included in its efinition of an infringer, "A person who
does that which the courts had previously held to be contributory inf ingement wherein there was an intent o infringe, but not necessarily the sal of a
component part of a combination p tent.
It protects against one who aid and
abets the direct infringer."
Then of the law as it had bean interpreted before the passage o this
present statute the court added, Prior
to the enactment of this statu" the
courts had recognized as contrirutory
infringers those who knowingly committed an act without which inf ingeThe QUAD full range electrostatic ment would not have occurred trough
loudspeaker (World's First) "offers a they did not s.11 a component p rt of
purity of sound that comes to the ears the invention.
as a completely fresh experience ... and
"This included the architect who
sharpens the senses with an apprecia- planned and supervised the co struetion of just how good electronically tion of the infringing machine, the salesreproduced music can be." You are man who solicited orders for t e ininvited to audition a QUAD music fringing device; and a person wh used
system at any one of our carefully trade secrets to construct an infr nging
selected franchised dealers. For partic- machine for the direct infringer.'
ulars, write to personal attention of
Mr. I. M. Fried.*
Intent is Essential
i
"By furnishing parts it makes it possible for others to assemble and use the
combination, and when a manufacturer
by so manufacturing and advising points
out the way in which this can be done,
and thus, intentionally so acting, promotes infringements of a patentee's
rights, he becomes a contributory in-
fringer.
"In the last analysis the fundamental
thought is that before one may be held
for contributory infringement, it must
be shown that he had knowingly done
some act without which the infringement would not have occurred."
By a Supreme Court decision rendered over a century ago, has been established the boundaries of this law and
the distinction between replacement or
repairs and reconstruction or infringement. A mill owner in Lousisiana had
purchased a patented planing machine.
After some years the purchaser replaced
the wornout knives and for so doing
was sued by the manufacturer for the
infringement of this patent.
Ultimately the action came before the
United States Supreme Court for review. That court holding that the mere
repair or replacement of these wornout
knives was not infringement, summarized the law, and the statement made at
that time has remained the rule.
"The right of the purchaser to replace
the cutter knives is not because they are
of perishable materials but because the
inventor of the machine has so arranged
them as part of its combination that the
machine could not be continued in use
without a succession of knives at short
intervals. Unless they were replaced the
invention would have been of but little
use to the inventor or to others.
"The other constitutent parts of this
invention, though liable to be worn out,
are not made with any reference to the
use of them that will require replacement. These without having a definite
In a decision rendered a few ::onths duration, are contemplated by the inlater added clarity was given this inter- ventor to last so long as the materials
pretation by the Federal District Court of which they are formed can hold together in use in such a combination. So
in Maryland. There intent and nowlit is understood by a purchaser and beedge of the purpose of the ac were
emphasized as essential features f the yond the duration of them, a purchaser
of the machine has not a longer use.
offense.
"To constitute contributory in ringe"But if another constitutent part of
ment," said that court. the device mr ma- the combination is meant to be only
terial capable of infringing use ii ust be temporary in the use of the whole, and
sold with the intent that it shal be so to be subsequently replaced, because it
used. When a manufacturer make., uses,
will not last as long as the other parts
or sells an unpatented element, he beof the combination, its inventor cannot
only
comes a contributory infringe
complain if he sells the use of his mamade,
knowingly
when the element is
sold, or to be used as a part of t e pat- chine, that the purchaser uses it in the
way the inventor meant it to be used
entable combination.
I
s
e
i
`
Quotes from the article "Walker's Little Wonder;'
by Robert Charles Marsh. High Fidelity Magazine
:
Power Amplifier
FM
Tuner
Stereo Control
Freedman y. Friedman, 142 F
Maryland, June 20, 1956.
6 Jones v. Radio Corp. of Americ
131 F.S. 82, April 26, 1955.
5
Lectronics of City Line Center, 7644 City Line Ave.,
Philadelphia 31, Pa. (Exclusive U.S. agents for the
Acoustical Manufacturing Co. Ltd., Great Britain). In
Canada: J. B. Smyth Co., 380 Craig St. W., Montreal.
..
,
426,
et al.,
and in the only way in which the mat7£
chine can be used.""
7 Wilson
ary, 1850.
v.
Simpson, 50 U. S. 108, Janu-
AUDIO
94
www.americanradiohistory.com
AmericanRadioHistory.Com
SEPTEMBER, 1959
BEYOND COMPARE
AUDIOCLINIC
(from page 4)
is one of the advantages of the system, for
using it enables us to run very long lines
indeed. Because the impedance is quite
high, the wiring need not be heavy with
regard to wire size. Because the voltage is
even lower than that provided by the a.c.
supply line, the insulation around the wire
carrying the 70-volt signal need not be
heavy either. It is a had system at least
so far as high fidelity applications are concerned, because the amplifier must be run
at its maximum Bower in order to get the
full 70 volts. Also, the transformers needed
between the speaker and the amplifier are
usually note too good. Hence, some sacrifice of quality would be noted. The transformer should he connected between the
amplifier's I0 -volt point and the speaker or
crossover network.
In installations where the amplifiers serve
many speakers, such a system is a good
one.
Now that I have discussed the merits and
demerits of the system in terms of what we
come to think of as good sound reproduction, I'd better explain just what the system is electrically. It is a system similar
to the 117 -volt 1.e. distribution system with
which most of us are familiar (220 -volt
system are in use in European countries
and elsewhere. With this system, the output voltage of the amplifier remains sub)
stantially constant, regardless of load. The
matching transformer used between this
circuit fund the loudspeaker or speakers are
tapped -not in terms of impedance, but
rather, in ternis of the wattage to be supplied to the speaker.
the station being received. Can you supply
an explanation for this problem? Thomas
1V. Weber, Ithaca, N. Y.
A. The trouble you are experiencing with
your tuner may be the result of several
things: 1 The filters in the power supply
circuit may be losing capacitance, and
therefore, their filtering efficiency is impaired. 2) There may be a heater- cathode
leak in the oscillator tube. If this is the
ease, the hum appearing in the output of
the detector will be 60 -cps hum, corresponding to the frequency of the filament supply.
3) The filament bypass for the oscillator
may have opened.
In any event, the hum you notice is
caused by a small deviation in oscillator
frequency in accordance with the line frequency or power -supply ripple frequency.
"But," you ask, "if the oscillator is shifting, why doesn't that cause a constant
hum, regardless of signal strength$" The
answer is this: In order for an FM detector
to produce a signal, there must be sufficient
voltage fed to it. The oscillator voltage
alone cannot be detected because it operates on a fr. quency different from that of
the i.f. system of the tuner, and hence it
cannot pass through the i.f. strip and
therefore, of course, cannot reach the detector. When a signal is tuned in, the oscillator beats with it and enables the heat frequency band thus produced to pass
through the i.f. stages of the tuner. In your
case you have two separate means by which
the i.f. signal is frequency modulated. One
is that of the carrier's intentional deviation -the desired program information
and the other is that of the oscillator's
deviation-the unwanted. Obviously, the
oscillator should be a steady frequency.
All of the foregoing assumes that the
tuner does not employ a.i.e. This circuit is
connected across the oscillator tank circuit
in sonic tuners, and if the parameters connected with this a.f.c. circuit vary in accordance with a filament or B supply variation, the tendency of this deviation will be
to cause the oscillator to deviate in accordance with it.
)
ma ira Gitz
FM tuner worked fine for over a
year. Now sonic trouble' has developed. Up
here- in Ithaca, I can get three strong stations. When I tune to any one of theme, I
get a very high hum level which can be
removed only by attenuating the bass on
my preamplifier. Between stations I get no
noticeable hum, even when the volume control on the preamplifiers is turned above
normal lev(1. This would appear to be contrary to the usual situation in which hunt
Ze
M' console
$249
Consumer Net
Cabinet
24
Slightly higher in West
In pre -amplifiers and power
ampli-
fiers, Marantz has set today's highest
standard of quality.
Consider the Marantz Stereo Console.
Here is the essence of uncomplicated, beautiful styling. So simple to
use, even the most non -technical
person can easily achieve matchless
reproduction quality. Yet, this fine
instrument offers an order of versatility that pleases the most discriminating professional users. Carefully
planned circuitry and wiring layout
result in unsurpassed freedom from
distortion, hum and noise.
Dedication to quality in every detail
is the reason why the Marantz 30watt power amplifier, too, is in a
class by itself. The Marantz circuit
permits this superb amplifier to recover instantaneously from sharp,
musical transients
to effortlessly
drive loudspeakers of all types
to
consistently outperform amplifiers of
considerably higher ratings.
-
FM Tuners
Q. My
is always audible, but can be overridden by
-
-
both stereophonic and monophonic programs, Marantz is your
assurance of long, carefree operation
and unprecedented performance.
For
ALL FOR ONCE, ONCE FOR ALL
/cor page
instrumentation was most compatible
with the Hall.
The story of the Crucifixion was recited by the narrator in a special script;
simply, it told of the immediate events
leading up to Christ before the Cross,
as depicted in the Styka painting. At
an appropriately dramatic point, the
huge curtains, weighing two -and -a -half
tams, were slowly withdrawn. It took a
full two- and -a -half minutes, during
AUDIO
SEPTEMBER, 1959
AUDIO
SEPTEMBER, 1959
23)
which time the audio men began to
scramble to adjust for the complete
change in acoustics within the auditorium. Exposing 11,775 square feet of
resonant canvas where a minute before
had hung a sound- deadening curtain was
like slowly turning up the treble control
while you upped the base control twice
as fast.
Knob turning and level checking was
30 -WATT AMPLIFIER
Net
*
$147
Slightly higher
Grill 7.50
in
West
Selected for demonstration at the
American Natl. Exhibition in Moscow
mtrOitlik
Mt N
CO MP
NY
A
25.14 BROADWAY, LONG ISLAND CITY 6,
N. Y.
95
97
Bound Volume of AUDIO Magazine
IMPORTANT
CLASSIFIED
LETTERS
(from page 10)
SAVE
25%
microphone placing," discusses studio techniques with illustrations.
icro4. A. C. Davis and P. C. Erhorn,
phones and Their Placement," And' Engineering Society, Fourth Lecture ".eries,
1957 -1958. Motion picture technic e is
discussed in Lecture 4.
ents
5. J. G. Frayne and H. Wolfe, El
of Sound Recording, Wiley, New York,
1949. Chapter 3, "Microphones and Their
Uses" and Chapter 31, "Acoustics of tages
and Theatres" are particularly h 1pful.
Motion picture technique is emphasiz d.
6. H. M. Gurin, "Broadcasting studio
pick -up technique," AUDIO ENGINE RING,
February, 1948, p. 9. Miking of ore estral
groups is emphasized and bidire ional
microphones are favored. Even thou h the
ribbon microphone has its faults an may
d reseem passé, it is still, today, the
liable with many sound pick -up eng neers.
7. J. P. Maxfield, "Liveness in rroadcasting," Western Electric Oscillator Jan uary, 1947 ; also J. P. Maxfield and ". J.
Albersheim, "An acoustic constant f enclosed spaces correlateable with the r apparent liveness," J. Acoustical Society of
America, January, 1949, p. 71. These
papers provide the theoretical basis fir the
'king.
single microphone technique of
icroWith judicious use of spotlight
phones, cracked just a bit to sweet:n the
sound, and with recognition of the Haas
or precedence effect, these papers hould
enable the engineer to make a reas nable
first choice for microphone positions
8. R. S. Oringel, Audio Control 0 and book. Hastings House, New York, 1956.
Chapter 3, "Microphone use techn'.ues,"
provides some extra data on studio practice.
9. M. Rettinger, Practical Electro- .coustics, Chemical Publishing Co., New York,
1955. Pages 46 -58, on microphone techniques, summarize studio practice.
For my purposes, reference 1 is a required text, with 7 adding useful s . ckup
in theory. References 3 and 6 are also helpful for illustrating situations ofte met
in practice. I should emphasize agai that
these are for monophonic, not stereo
pickup.
c
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treet
765 Hobart
Menlo Park, Calif.
Name
Address
Renewal
New
Name
Address
7
Renewal
New
U. S., Possessions, and Canada only
RADIO MAGAZINES, INC.
P.
0.
Box 629,
Mineola, N. Y.
ssw.
per well per Insertion fer
.nlal
adrertisemeab; 25t per weird far mamerelal advertisements. Bates are net, and no dheeents will be
allowed. Cary ant M ueemrsnled by remittent, la
fall. wed mut reuh the New York Dike by RN
Brat of the month preceding the date et Issos.
Satu: 100
3. British Broadcasting Co., En: ineering Training Manual, Studio Engin ering
for Sound Broadcasting," Iliffe and Sons,
London, 1955. Chapter 3, "Acousti c. and
ERRATA
As it does occasionally to all p inted
matter, some errors crept into the rtiele
on "FM -Band Reception in Fringe reas,"
by W. N. Coffey. The diagram for ig. 3
ched,
on page 20 was apparently over
causing the complete elimination o some
of the lines, as well as the tube -e ment
designations. The tube type, 6922, is hown
in its proper position above and b tween
the two sections, and two curved lines
should extend from the number to t e arrows on the tube symbols. The left riode
TRADE UP TO STEREO : Largest selection
of new, used Hi-Fi components. Professional
service facilities available. Write Audio Exchange, Dept. AE, for trading information.
153-21 Hillside Ave., Jamaica 32, N. Y.
Branches in Brooklyn, White Plains, Manhasset.
HIGH FIDELITY SPEAKERS REPAIRED
Amprite Speaker Service
70 Vesey St. New York 7, N. Y. BA 7 -2580
ENJOY PLEASANT SURPRISES? Then
write us before you purchase any hi -fi. You'll
be glad you did. Unusual savings. Key Electronics, 120 Liberty St., New York 6, N. Y.
EVergreen 4 -6071.
WRITE for confidential money- saving
prices on your Hi-Fidelity amplifiers. tuners,
speakers, tape recorders. Individual quotations only ; no catalogs. Classified Hi-Fi Exchange, AR, 2375 East 65th St.. Brooklyn 34,
N. Y.
INDUCTORS for crossover networks. 118
types in stock. Send for brochure. C. & M.
Coils, 3016 Holmes Ave., N. W.. Huntsville,
Ala.
UNUSUAL VALUES. Hi -Fi components,
tapes, and tape recorders. Send for package
quotations. Stereo Center, 18 W. 37th St.,
N. Y. C.
-
FINEST QUALITY recording tape
7"
reels. 30- 15,000 cps guaranteed.
1200' Acetate, 3/$4.05 -6/$8.00
1800' Acetate, 3/$5.10 -6/$10.00
1200' Mylar, 3/$4.80- 6/$9.00
1800' Mylar, 3/$6.60- 6/$13.00
2400' Mylar, 3/$9.60 -6/$19.00
Add $.15 PP and handling. FOTO- SOUND,
88 Harbor Road, Port Washington, N. Y.
SELL : IBM electric typewriter, $75 Aerosound Ultra- Linear amplifier, $50 Belt -driven
professional turntable, synchronous motor,
B -J Arm, $35 : Approved A -800 preamplifier,
$15. "Ted" Hein, 418 Gregory, Rockford.
Illinois.
:
:
RENT STEREO TAPES-over 800 different-all major labels -free catalog. Stereo Parti, 1608 -H Centinela Ave., Inglewood 3.
California.
SCOTCH recording tape at 'Profit- sharing'
prices -send for catalog- you'll be glad you
did Tapeco. Dept. H, P. O. Box 4353. Ingle word 3, California.
SALE 78 rpm recordings. 1900-1950. Free
lists. Collections bought. P. O. Box 155 (AU),
:
Verona, N. J.
CROSSOVER NETWORK KITS. Custom
and contract coil winding. Write Watson Industries. 110 Mildred, Venice, California.
SELL Pentron CA-13 tape record /play
preamp. $37. Robert Stafford. 1044 Glendale
Ave., Columbus 12. Ohio.
SELL 50 LP's, 10 LP albums. monophonic, played very little-$90. Electro -Voice
T250 driver. 6HD horn, X6 network, AT37
level -$100. Jim Lansing 375 driver, N500
network, 537 -509 horn lens-$280. University
C15W woofer-$60. Excellent condition. Prepaid. John Haner, 683 Locust, Galesburg, Ill.
:
:
REPLACEMENT 12" record album envelopes with built -in cellophane liners. State
color. 12 for $2.00. Prepaid. Neilson Enterprises. 120 Henry St., South Amboy, N. J.
will solve your hi -fi
HI-FI DOCTOR
problems on- the -spot. Acoustic, audio, radio
engineer. Stereo designing. Professional visits, day. evening. New York area. William
Bohn, Plaza 7- 8569, weekdays.
New Wharfedale moving -coil
SELL
speaker, W /FS 15- inch -$60. O. Heim. 131
Thompson St.. New York 12, N. Y. SPring-
-
:
7 -7937.
MORE CLASSIFIED ADS ON
PAGE 99
AUDIO
98
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SEPTEMBER, 1959
PROFESSIONAL
DIRECTORY
Fastest, Easiest Way To Learn All About
Audio
NEW Rider "Picture- Book" Course
BASIC AUDIO
section should have been numbered 1 for
plate, 2 for grid, and 3 for cahtode; th,
right triode section should have been nun)
bored 6 for plate, 7 for grid, and 8 for
cathode. Heater terminals are 4 and 5, and
the wiring data shown adjacent to the
transformer secondary should read "Ti,
pin 5 of 6922; Ground pins 4 & 9."
We trust this has not inconvenience)
anyone who has tried to construct it.
LONG
AWAITED...NOW
by Normans H. Crowhurst
The Rider "picture- book" approach has made
many technical subjects understandable to
many
hundreds of thousands of people. Now, everything
about sound and audio reproduction
is
crystal- clear. If hi -fi is your interest -or ifmade
you
work with tape recorders -or the broad subject
of sound reproduction interests you, -or if you
assemble your hi -fi equipment or buy
a complete
"package"-you must read BASIC AUDIO.
If you already own sound reproducing equipment
-this "picture- book" course will give you an allaround background on all the important details
sound reproduction. It wi:1 enable you to get of
the
most from your equipment.
You can learn easily, rapidly at very low
cost.
You build your knowledge step -by -step.
There's
one idea and one specially prepared illustration
per page. More than 400 illustrations for maximum understanding.
Beyond a knowledge of electricity at
the basic
level, no previous electronic experience
is needed
to get the maximum from this course. Whatever
electronics circuit theory is required to
make
entire panorama of sound reproduction and the
recording visible to you is provided.
This Rider "picture- book" audio course
is completely different from anything that has ever been
presented. We guarantee your satisfaction.
#201, 3 vols., soft covers
$8.70 per set
At your robber or book tore, or order
direct A9
John F. Rider Publisher, Inc., 116
W. 14th St., N. Y. 11
In Canada: Charles W. Pointon5_
AlcinaAve., Tororto
Circle 99C
Allan W. Greene
been appointed
president of the Heath Company,
Benton
Harbor, Michigan, according to Thomas
Roy Jones, president of Daystrom, Incorporated, of which Heath is one of ten
operating divisions. Mr. Greene was general manager of Moto- Mower, Inc.,
HWchmond, Indiana, and a vice- president of
Detroit Harvester Company, of which
Moto- Mower is a subsidiary.
Herb Horowitz, occasional contributor
to these pages, has been appointed director
of Audio Empire, high fidelity product arm
of Dyna- Empire, Inc., Garden City, N. Y.
Before joining Dyna- Empire, Mr. Horowitz spent many years as chief engineer
of Eleeto -Soni, Laboratories and chief of
audio products for CBS Columbia, during
which time he was responsible for a number of outstanding adv:uues in the design
of high fidelity components. Duties will
include marketing and pronn,ton as well
as engineering supervision.
Newark Electric Company, he:ulyu:u-tered at 223 W. Madison St., Chicago G,
Ill., has purchased additional land for
their west Coast branch at 4747 W. Century Blvd., Inglewood, California, with
the area to be devoted to customer parking until further expansion requires larger
building area.
I
recording tape
$1.19
WANTED: MICROPHONE DESIGN AND
DEVELOPMENT
kieruiff
SOUND CORPORATION
820 W. OLYMPIC BLVD., LOS ANGELES 15, CALIF.
FAY/Q,
ANTENNAE
I.
Get more FM stations with the world's most
powerful FM Yagi Antenna systems.
Send 250 for booklet "Theme And Wale-
bons" containing FM Station Directory
APPARATUS
DEVELOPMENT
Wethersfield
9,
CO.
Connecticut
Circle 99E
P
TAPE
DECK
ayboa',
confidence
to
Lee
11th
St., C'level :npl 14, Ohio.
Employaient
Service,
MAJOR BRAND RECORDING TAPE. Manufactured und nationally advertised by one
of
the four autjoI. U. S. eiituruliea. 1300 ft.
genuine DuPont Mylar. i'irst quality, no
splices. brand new. foil refund if unsatisfied.
Not tu lie confused with inferior tapes. $1.89
each. ln for $1$.00, 101 for $170.00 Include
postage. S & F I'leetrouies, 7!159 Melrose Ave.,
1.os Angeles 40. California.
BEST
A auto,
...
$129.95
only
achievement In tape deck d,'sIgn and per
e AItKAY /iI. It'll XG rrror'Is your favor:.
fornla
music srn:, lu same superb performance of tape recors e,
Clint Inc many tintes more. .\ n olhn tom. deck
regardless
of Price
offers no many Ern part,' rrt feiltlire*'. 11ere s Ju't a
tlN':
-
-
'.g
all -met. tare fneers. drop -in
IoaJinv
4h- met:,. tape n, -r Is
1.arre(h "Man -) op *tan
Sire: 1í.n;" 14ír" a 6i s"
Dual -track combination head for
too
speeds
30-1f,1 CO cps
2 db.
FR.ab r and re,.: I, of
Five -button opera ion
5S db. S; N
I%
-
deep.
The AI:KAY /11%Itl'I NG will be al your dealer's serin,
also a tereo re -..rd and playback pre- ansplItlrr. in kit of
pre-wired foret, sprriatl ,.r<i, nod for the ARICAY/
HARTING.
ARRAY
: -F STEREO
C:
C
CS -28
AMP /PRE -AMP
COMPLETE
!
CONTROL
CENTER
Full 28 watts stereo or monaural, 60 watts peak
14 watts each
channel
reverse stereo
balance control
two-channel gain
control
full range bass and treble controls IM distortion,
to 1
harmonic distortion, :% 30-20,000 cps dual pre-amp 2V
output jacks
speaker outputs, 4, B. 16, 32 ohms
respcnse,
20- 20.000 cps
push -pull EOM Williamson circuit.
Easy -to-build Kit
Wired and tested $99.95
Write today for
mplete. detsil'd illsstrated lh erate
w nod
See and s hear
ARRAY
FREE! Stereo booklet and
,B
$ÓY95
prc,,t ions.
Oc
Kits at your dealer.
catalog. Write Dept. A.
All prices S% hiCMr west of Mississippi
101;06 Van Wyck Expressway
&almond
Hill 18, N.Y.
Circle 99A
ENGINEER
Electrical and acoustical design and development of crystal, ceramic, and dynamic
micrai:hoaes for quality manufacture.
Analysis und solution of problems encountered in the production of various types of
microphones and associated products. Experience in the use of piezoelectric materials for audio applications, magnetic
structures and microphone design desirable. Salary to $10,000, de "siding on experience. Interview expense paid. Fee and
relocation negotiable. Submit resume in
1940 East
Crcic 99D
M° -5
STEREO
popular price
ADDITIONAL CLASSIFIED ADS
"-
Arkay /Harting
Professional quality at o
special
1200 ft.; 7
guaranteed splice -free
1800 ft.; 7"
. $1.89. Enclose
100 for
each reel to cover postage and handling.
AT LAST!
HERE
the
settle for ordinary
THE Why
tape when Sonoramic
gives you
many
exclusive extras CASE brilliant
reproduction,
permanent plastic
FOR
container, -way
indexing system
with pressure
BETTER sensitive
labels
so
3
SOUNDand
V-slot so
threading Selection
Finder reel,
IN HI -FI VALUES!
NO
DELAY
SERVICE
All orders rushed to you
in factory -scaled cartons.
Write for free catalog.
25 -A Oxford Road
Massapequa, New York
CANADA
High Fidelity Equipment
Complete Lines
Complete Service
11I
-FI Records
- Compn
sLECTRO1)Oi
SOUND SYSTEMS
126 DUNDAS ST. WEST, TDRONTO, CANADA
100K
o
further
AUDIO
If ye're
w
FREETapetime ruler. Gives you.
footage and recording time on reel. Write Dept.R:¡1`7
went. new...
Kew
170
EIctreIcs
twsepee.
rtgsrptt,J7.0
e
Y
EV 4
Circle 99F
.
searching for hl -fl acing
Write es your reel islee
-6071
Circle 99H
4/tL
ng7 cod CORPORATION,
LODI, NEW JERSEY
Circle 99B
SEPTEMBER, 1959
99
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¿ije/fe Superior Quality pli -fl Kits
OUTSTANDING DESIGN
-
ADVERTISING
INCOMPARABLE PERFORMANCE
KT -250
INDEX
50 WATT INTE-
GRATED STEREO AMPLIFIER
KT -250
LA -250
IN KIT FORM
COMPLETELY WIRED
64.50
I
89.50
-
50
25 WATTS
WATTS MONAURALLY
EACH STEREO CHANNEL
RESPONSE 1721,000 CPS 2:1 DB (ut normal listening
level)
UNIQUE "BLEND" CONTROL
SEPAPREMIUM EL86 OUTPUT TUBES
RATE BASS ARID TREBLE CONTROLS
CONTROL
CLUTCH- OPERATED VOLUME
3rd CHANNEL OUT
A completely new stereo high fidelity amplifier
with a high quality of reproduction, versatility of
operation, and distinctive styling.
A full range of controls enables you to enjoy the
utmost in listening pleasure in any situation. Deluxe features include: unique "Blend" control
for continuously variable channel separation
from full monaural to full stereo, 4- position
Selector, Mode, Loudness and Phase switches.
Also provided are outputs for 4, 8 and 16 ohm
speakers. Hum -free operation is insured by the
use of DC on all preamp and tone control tubes.
Harmonic distortion, less than 0.25%. IM distortion, less than 1%. Hum and noise, 74 db below
full output. Designed with the kit builder in
mind, assembly is simple -no special skills or
tools required. Complete with deluxe cabinet and
legs, all parts, tubes and detailed instruction
manual. Shpg. Wt., 26 lbs.
6.45 Down
KT -250 Stereo Amplifier Kit
Net 64.50
8.95 Down
LA -250 Stereo Amplifier, wired
Net 89.50
-
KT -500 FM -AM
STEREO TUNER KIT
More than a year of research, planning and engineering went into the making of the Lafayette
Stereo Tuner. FM specifications include grounded grid triode low noise front end with triode mixer,
KT -500
LT -50
IN KIT FORM
COMPLETELY WIRED
74.50
124.50
Multiplex Output fcr New Stereo FM
11 Tubes (including 4 dual- purpose)
Selenium rectifier Provide 17
Tuning Eye
Pre -aligned IF's
Tube Performance
Dual Cathode
Tuned Cascode FM
Follower Output
double -tuned dual limiters with Foster -Seeley discriminator, less than 1% harmonic distortion, full
200 kc bandwidth and sensitivity of 2 microvolts
for 30 db quieting with full limiting at one microvolt.
The AM and FM sections have separate 3 -gang
tuning condenser, separate flywheel tuning and
separate volume control. Automatic frequency
control "locks in" FM signal permanentlly. Two
separate printed circuit boards make construction
and wiring simple. Complete kit includes all parts
and metal cover, a step -by -step instruction manual, schematic and pictorial diagrams, Size is
133/4" W x 103/2" D x 41/2" H. Shpg. wt., 22 lbs.
Net 74.50
KT -500
7.45 Down
LT -50. Same as above, completely factory wired
Net 124.50
12.45 Down
and tested
KT -600 PROFESSIONAL
Solves Every Stereo /Monaural
Control Problem!
¡
LA -600
IN KIT FORM I COMPLETELY WIRED
79.50
i
134.50
Provides such unusual features as a Bridge Control, for variable cross -channel signal feed for
elimination of "ping -pong" (exaggerated separation) effects. Also has full input mixing of monaural program sources, special "null" stereo balancing and calibrating system. Also has 24 equal-
ization positions, all- concentric controls, rumble
and scratch filters, loudness switch. Clutch type
volume controls for balancing or as 1 Master
Volume Control. Has channel reverse, electronic
phasing, input level controls. Sensitivity 2.2 milvolt out. Dual low -impedance outlivolts for
puts (plate followers), 1500 ohms. Response 540,000 cps ±
db. Less than .03% IM distortion. Uses 7 new 7025 low -noise dual triodes.
Size 14" x 41/2" x 101/2". Shpg. wt., 16 lbs.
Complete with printed circuit board, cage, profusely illustrated instructions, all necesscry parts.
LAFAYETTE KT -600- Stereo Preamplifier kit
Net 79.50
7.95 Down
LAFAYETTE LA-600- Stereo Preamplifier, Wired
Net 134.50
-13.45 Down
1
A REVOLUTIONARY DEVELOPMENT
IN STEREO HIGH FIDELITY.
UNIQUE STEREO & MONAURAL CONTROL
FEATURES
AMAZING NEW BRIDGE CIRCUITRY FOR VARIABLE 3d CHANNEL OUTPUT
PRECISE "NULL"
CROSS- CHANNEL FEED
RESPONSE 5- 40,000
BALANCING SYSTEM
CPS
1 DB
±
P.O. ROX 222
JAMAICA 31, N. Y.
1
-
DEPT.
AI-9
Send FREE LAFAYETTE Catalog 600
CUT OUT
Name
AND
PASTE ON
Address
POSTCARD
1
City
-
41
10
34
99
99
83
92
47
96
82
27
85
39
57
99
Bell Telephone Laboratories
Bogen- Presto Company
Bradford Audio Corp.
18
59
93
British Industries Corporation
3
A Division of
Columbia Broadcasting System, Inc.
Classified
Connoisseur
Cosmos Industries, Inc.
CBS Electronics,
90
98
91
49
80
89
Dexter Chemical Corp.
Dynaco, Inc.
13
EICO
Electrodyne Corporation
Electra -Sonic Laboratories, Inc.
Electro- Voice, Inc.
Electro -Voice Sound Systems, Inc.
Ercona Corporation
Ferrodynamics Corporation
Fisher Radio Corporation
97
58
Cov. IV
99
91
.
99
25, 54, 55
53
Fukuin Electric (Pioneer)
Fukuyo Sound Co., Ltd., (Coral)
86
15
General Electric
Gotham Audio Sales Co., Inc.
Grado Laboratories
Gray High Fidelity Division
Harman Kardon
Heath Company
86
84
51
43
7 -9
99
99
Key Electronics
Kierulff Sound Corporation
STEREO CONTROL CENTER
KT -600
37
79
Acoustic Research, Inc.
Allied Radio Corp.
Altec Lansing Corporation
Amperex Electronics Corporation
33,
Ampex Corporation
Apparatus Development Co.
Arkay
Arnhold Ceramics, Inc.
Atlas Sound Corp.
Audax Division of the
Rek -O -Kut Co., Inc.
Audio Bookshelf
Audio Devices, Inc.
Audio Empire, Div. of Dyna Empire Inc.
Audio Engineering Society
Audiogersh Corp.
Audio Fidelity Inc.
Audion
Kingdom Products Ltd.
KLH Research G Development
Corporation
Klipsch and Associates, Inc.
5
64
88
100
29
94
Lafayette Radio
Lansing, James B., Sound, Inc.
Lectronics of City Line Center
Marantz Company
McIntosh Laboratory, Inc.
ORRadio
95
67, 68
Industries, Inc.
88
92
Partridge Transformers
Pickering Cr Company
Pilot Radio Corporation
Professional Directory
17
31
99
Radio Corp. of America
Radio Shack Corporation
Reeves Soundcraft Corp.
Rider, John F., Publisher, Inc.
Rigo Enterprises, Inc.
Roberts Electronics, Inc.
Rockbar Corporation
Coy. II
65
97
99
87, 93
14
Coy.
Scott, H. H., Inc.
Sherwood Electronics Laboratories
Shure Brothers, Inc.
Stromberg- Carlson, A Division of General Dynamics Corporation 60, 61, 62,
Studio Supply Co.
Tandberg of America, Inc.
Tung -Sol
III
77
1
81
63
91
22
University Loudspeakers, Inc.
45
Weathers Industries
78
Zone.... State
AUDIO
100
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SEPTEMBER, 1959
our
British
cousins
at
Collaro
stress
meticulous
care and
precision
engineering
in every
Collaro
Go
stereo
record
player!
The Constellation, Model TC
-99- $59.50
Transcription Turntable, Model 4TR- 200-$49.50
The Continental I1, Model TSC- 840 -$49.50
II, Model TSC- 740 -$42.50
*The Conquest II, Model TSC- 640 -$38.50
The Coronation
Manual Player, Model TP -59- $29.95
Every Collaro stereo record player is built with typical British attention to every detail.
They are precision engineered and rigidly tested to give truly professional performance and the ultimate in operating convenience. Here are some of the important
features that make Collaro the logical choice for stereo or
monophonic records.
Performance specifications exceed NARTB standards for wow, flutter and rumble -with actual performance
test reports accompanying each model TC -99.
Extra -heavy, die -cast, non -magnetic turntables (weighing up to 81/2 lbs.). Extra -heavy weight is carefully
distributed for flywheel
effect and smooth, constant rotation. Shielded four -pole motors are precision balanced, screened with triple interleaved
shields to provide extra 25 db reduction
in magnetic hum pick -up.
Detachable five -terminal plug -in head shells (on TC -99, TSC -840, TSC -740, TP -59) provide two completely independent
circuits, guaranteeing ultimate in noise reduction circuitry.
Transcription -type stereo tonearms are spring- damped and dynamically counterbalanced to permit the last record
on a stack to be played with virtually the same low stylus pressure as the first.
All units are handsomely styled, available with optional walnut, blond and
mahogany finished bases or unfinished utility base. There's a 4 -speed Collaro stereo record player
for every need and budget! Prices slightly higher in the
West. For free catalog on the Collaro line, write to. Rockbar Corporation, Dept. A -9, Mamaroneck,
N. Y. ( *Not shown. Similar in appearance to The Coronation.)
THE ONLY ULTRA -COMPACT
-WAYWIDE -RANGE
SPEAKER SYSTEM
designed for true stereo
racz
HIGH FIDELITY
RE GAL
Gives yo bass so low you can feel it ...bass you would expect
from a onventional enclosure three times the size. Gives you
balanced full -range, flat response without attenuation or peaks.
Ideal as an economical "first" system.,
an "add -on" or in a pair for stereo
You n ed not be an acoustical engineer to understand
why t ere is so much stereo value in this ultra- compact
speak: r system. The same exclusive features that have
alway made ELECTRO-VorcE systems best for monand
aural re an absolute necessity for true stereo
you g these vital features in the REGAL III.
Acoust tally- correct enclosure is matched to specially-
...
12 -inch LF driver for exceptional extension of bass
and unusual dynamic range ... without sacrificing
efficien y and without the need for unusually -large amplifier
power.
E -V S per Sonax vxF Compression Driver with exclusive
Sonop se* throat design assures you of the smooth, spar klingha hs so necessary for precise musical blend and balance.
E -V Di raction, in both the Horn- Loaded Mid -Range Driver
and th Super -Sonax Tweeter, gives you all- important
design
respon
iE3
I
11
CI
so esse tial for all -position stereo listening. By wide -angle
(180 °) .iffraction, the higher frequencies are completely
dispers d smoothly and evenly throughout the listening area.
This inures proper fusing of the significant stereo sounds
from t o speaker systems in controlled and varying proportions ... gives true depth and placement to the musical instrume is simultaneously, without spatial distortions . .
assures asy listening from anywhere in the room. Convenient bu concealed "Presence" and "Brilliance" controls permit qu' k and easy musical balancing to room acoustics.
Luxurius furniture -crafted enclosure is finished on all four
sides fo placement anywhere on shelf qr floor.
.
u
REGA
III. Complete 3-way system
in
Walnut,
ahogany or Limed Oak. Size
12 % "d,
enclosure, ready to use. Choice of
13'4"h, 24"w. Net, $147.50
ESQUIRE 200. Economical version of the
Regal. Complete 3 -way system in modern enclosure, with single rear -control.
12 -inch bass speaker, special 8 -inch
cone mid -range driver, and Super -Sonax
diffraction -horn compression tweeter.
Choice of walnut, mahogany or limed oak.
121/2"d, 131/2 "h, 24 "w.
Net, $111
See
t
At yo r
- Hear it - Enjoy it E -V
on Money -Back Guarantee.
high -fidelity dealer or write for Catalog No. 134 to Dept 99-A.
No Fine
Choic than
gleelZASI.CC®
ELECTRO- VOICE, INC., BUCHANAN, MICHIGAN
Design Patent No. 182351
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