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FEBRUARY 1965
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CONFIGURATION (B)
OF FIGURE 2
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CONURATION (A)
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VALUES OF
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.7
.8
.9
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EFFECT OF LINE
1130`
I
0
0
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125
120
VOLTAGE ON POWER
115
110
OUTPUT
105
Z
J
100
95
90
30
25
20
POWER
15
OUTPUT
IC
The Scott 340
... the
tuner /amplifier Electronics World said
"...must certainly be classed
as one of the finest integrated
tuner/amplifiers we have tested..: '*
SE,te,OP
LLIMo.r,
Oho
icLo
In review after review the critics are unanimous
in their praise of the Scott 340B Tuner /Amplifier.
It offers technical performance unmatched by
even the finest separate components.
The highly respected editors of ELECTRONICS
WORLD, in their June, 1964 issue had this to say:
"... from the first, it was evident that this was
a superior product. It has the utterly smooth,
clean sound which we normally associate with
the finest component systems.
"The husky Audio section of the 340B, which is
rated at 30 watts (r.m.s.) per channel delivers
/AIRS
MOr.
117.4
about 36 watts per channel with both channels
operating.
"The FM tuner is in the first rank in all respects.
IHF usable sensitivity (rated at 2.2 µv) measured
1.7
µv...
"... Suffice it to say that the unit
met, and in
many cases substantially exceeded, every one of
the ratings for which we were able to test. It is
not often that we can confirm EVERY published
specification of a high fidelity component, particularly one as complex as (this), and it was a
gratifying and pleasant experience ..." $399.95
TREE 1965 STEREO GUIDE
H
Scott, Inc
H.
lit
Powdermill Rd.. Maynard, Mass
.4;74
Scott 380 AM /FM Tuner /Amplifier has all of the features and
fine performance characteristics
of the 3408. It includes in adsuperb Scott Wide -Range
the AM circuit Hirsch AM
the finest
Houck Labs called
AM tuner we know of on the
dition,
current market." $469.95
Export
colt International.
III
Scott 345 FM Stereo Tuner /Amplifier. The moderately -priced 64watt 345 features Time -Switching
multiplex circuitry, famous silver
plated RF front end with 2.2 ev
IHF usable sensitivity, and most
of the other high quality features
of the 340B. Automatic indicator
light tells you when to switch to
stereo. Like all Scott components,
the 345 carries a full two -year
guarantee. $364.95
front end. Only
Silver- plated
Scott,
all
manufacturers,
of
heavily silver -plates cascode
front ends to attain maximum
sensitivity and most reliable
performance. In addition the
3408
and
perfected
multiplex
380
utilize
Scott -
"Time- Switching"
circuitry to provide
maximum separation and perfect
off-the-air recording.
Powdermill Road. Maynard, Mass. Canada: Atlas Radio Corp., 50 Wingold Ave. Toronto. Cable HIFI
Please send me your new 20 -page full -color
1965 Stereo Guide and complete catalog.
Send me complete information on new con.
component quality in
soles by Scott
beautiful, hand -finished cabinets.
35 -02
Name
Address
City
Zone.. -. State
0 S C OTT
Price slightly higher West of Rockies. Subject to change without notice.
Circle 100 on Reader Service Card
VOL. 49, No. 2
FEB., 1965
Successor to
RARI9 ,
Number
C. G. MCPROVDPublisher
AU
i
REACH
JANET M. DURGIN
Representatives
Bill Pattis & Associates,
4761 West Touhy Ave.,
Lincolnwood 46, Ill.
James C. Galloway,
6535 Wilshire Blvd.,
Business Manager
SANFORD L. CAHN
Advertising Director
Los Angeles 48, Calif.
Warren Birkenhead, Inc.,
No. 25, 2- chome, Shiba Hamamatsu -cho,
Minato -ku, Tokyo, Japan
EDGAR E. NEWMAN
Circulation Director
Characteristics of Shunted Potentiometers
Effect of Power Line Variation on Low Frequency Operation of Amplifiers
Temporary Sound Amplification Systems
Two Parts-Part Two
Special Electronic Organ Tone Sources
A New Look at FM
-In
19
2
23
30
36
3
50
62
42
2
3
JOSEPH GIOVANELLI
HAROLD LAWRENCE
CHESTER SANTON
HERMAN BURSTEIN
BERTRAM STANLEIGH
AUDIO Articles
Ronald L. Ives
George Lehsten
David L. Klepper
D. Wolkov
Harry Maynard
INS
E
OP
HIGH FIDELITY
INC.
(title registered
FEBRUARY, 1965
nique is effective at low and mid frequencies.
third problem is the production of harmonic
and intermodulation distortion at high frequencies. The narrow throat section typical of most
large reentrant horns gives rise to non -linear
compression of air. For example, a large horn
with 150 cycle cutoff and 743" diameter throat
produces about 17% second harmonic distortion
at 3kc with just one acoustic watt output from
the driver.' This type of distortion rises with
increasing frequency because it is proportional
to the number of wavelengths through which
ound passes at high pressure.
unique solution to the problem of high-level
propagation of high frequencies is the Electrovo:ce Model AC100 Compound Concentrating Projector. The driver is horn- loaded on both sides
of the diaphragm, with energy below lkc being
radiated from the rear into a large low -frequency
horn. Output above lkc radiates from the front
of the diaphragm into a small, short horn with
only two 90° bends, mounted coaxially with the
low frequency horn. Both horns have similar disp r -ion patterns for uniform coverage.
A
Profile
Model MR 71
Model C 24
Model 1010
Acoustech Ill
Stereo 200
Joseph Giovanelli
10
14
16
Edward Tatnall Canby
Harold Lawrence
34
54
56
56
64
Herman Burstein
harmonic distortion is significantly reduced in
the compound horn, due to the very short horn
length at high frequencies. Intermodulation distortion is also lessened since lows and highs are
eparated. The resultant lower distortion and ext, -nded frequency response increases intelligibility
in the listening area. A larger useful listening
area also results from the uniform distribution of
energy at all frequencies.
The AC100 horn and its matching drivers offer
an economical and efficient answer to problems of
extended reach. Its compact dimensions belie its
ability to extend sound coverage where low distortion and high sound levels are required.
t L. Beranek. Acoustics, p. 276.
For technical data on any E-V
Larry Zide
product, write:
ELECTRO- VOICE, INC., Dept. 253A
Buchanan, Michigan 49107
Z2
U. S.
RADIO MAGAZINES, INC., P. O. Box 629, MINF,OLA, N. Y.
Postmaster: Send Form 3579 to AUDIO, P. O. Box 629, Mineola, N. Y.
AUDIO
in applications where extended reach and high
efficiency are needed, such as at stadiums, athletic
fields, etc. Where maximum reach is needed,
large horns are often used to concentrate all of
the available energy in a narrow beam. This tech-
A
Chester Santon
Edward Tatnall Canby
Bertram Stanleigh
Pat. Off.) is published monthly by Radio Magazines, Inc., Henry A. Schober, President; C. G. McProud, Secretary. Executive
and Editorial Offices, 204 Front St., Mineola, N. Y. Subscription rates-U. S.,
Possessions, Canada, and Mexico, $5.00 for one year, $9.00 for two years; all
other countries $6.00 per year. Single copies 60g. Printed in U.S.A. at 10
McGovern Ave., Lancaster, Pa. All rights reserved. Entire contents copyrighted
1965 by Radio Magazines, Inc. Second Class postage paid at Lancaster, Pa.
AUDIO
s
4
Horn -and-driver loudspeakers are generally used
At high frequencies, however, the large horn
mouth is several wavelengths in diameter, so that
the radiated power is concentrated into an increasingly narrow beam that does not fully cover
the desired sound field. Secondly, the reentrant
folds in the horn path have dimensions on the
order of a wavelength at high frequencies. Acoustic losses are inevitable when the air path dimension at the bend is greater than about one quarter wavelength. Even with the use of wide-range
drivers, severe losses in intelligibility are encountered with large reentrant horns.
LARRY ZIDE
peral
Audioclinic
Letters
Audio ETC
About Music
Editor's Review
Tape Guide
New Products
New Literature
Cover Story
InZide Audio
Advertising Index
Loudspeaker Project Engineer
EDWARD TATNALL CANBY
AUDIO
McIntosh FM- Stereo Tuner
McIntosh Solid State Stereo Preamp
Dual Automatic Turntable
"Network" Spark Injector
Acoustech Solid State Power Amp
Benjamin Phono Playback System
JOHN R. GILLIOM
Contributing Editors
AUDIO Reviews,
Light Listening
Record Revue
Jazz and All That
ea
FOR
Production Manager
HENRY A. SCHOBER
series of discussions
THE SEARCH
Editor
DAVID SASLAW
18 in a
by Electro -Voice engineers
Est. 1911
eat
SETTING NEW STANDARDS IN SOUND
Circle 104 on Reader Service Card
1
Please read this message
concerning the advertisement on the facing page...
If you are a regular reader of this
magazine, you know that we have
been running a consistent series of
advertisements explaining the features of the Lab 80.
Furthermore, if you have had occasion to ask for a Lab 80 at your
dealer, or perhaps have already
ordered one, you know that this unit
is in very short supply. There is a
good possibility that your dealer has
not yet been able to deliver, unless
your order was placed many weeks
ago.
We realize that this kind of situation makes for misunderstandings
between consumers interested in
Garrard equipment and ourselves;
and between customers and their
dealers. All of them ask "Why do
you advertise the unit when you cannot fill my order ?"
We are sincerely gratified that
our products, and our advertising,
are generally so well received. We
want you to know that above all
other considerations, we value your
understanding and goodwill. These
are, and must remain, the cornerstones of our reputation and continued success. Therefore, we feel
constrained to detail the present
situation concerning the Lab 80, and
to explain why we not only continue
to advertise it, but must and should
increase this advertising.
Briefly, the matter is as follows:
1. The Lab 80 has been in production, and on the American market,
since late September, when we began shipping demonstration units to
dealers. However, Garrard products
have been sold in the U.S. since
1937, and we have a very large number of dealers ... so that you and
they can appreciate that it has not
been possible to ship all of them
"first." It poses quite a problem in
logistics to fill distribution channels
with the large quantities required of
this high quality product, which is
not mass -produced in the ordinary
sense ... all in just a few months.
2. We announced the Lab 80 in the
October issues of the high fidelity
publications. Since then, the interest
in this model has been staggering.
Furthermore, many of the original
orders placed by dealers have already been doubled again and again,
despite the shortness of time.
3. Since the Lab 80 is the very symbol of our reputation as the manufacturer of the world's finest record
playing equipment, we are extremely
rigid in its production and quality
control. Nothing is being allowed to
interfere with its quality, so that
production moves at a steady, but
not a frantic, pace. In plain English, we are insuring that every Lab
80 we ship is simply perfect ... and
this has been a matter for the entire
Garrard quality control organization
to guarantee.
4. Let there be no mistake about
the Lab 80 is being produced, in very
substantial quantities, and at an ever
increasing rate. Nevertheless, despite our best efforts, we still cannot
fill orders as promptly as we would
wish, because we absolutely refuse
to over-rush the numerous and essential processes involved merely in
deference to the pressure for de-
it-
livery.
5. We try to keep our distribution
policies as fair as possible. Therefore, dealer orders are highly controlled and filled (perhaps we should
say rationed) on a systematic and
equitable basis. This explains why
your dealer may have had to sound
so vague in trying to tell you exactly
when you would receive your Lab 80.
6. In view of this, we realize that
our advertising policy probably requires some explanation. It is well known that our advertisements generally are not written as much to
catch the eye as they are to inform
the reader.
We believe that in the high fidelity component field, particularly, the
reader must have a good interpretation of a product, in order to select
wisely ... and that it is the function
of our advertising to provide that information, up to the point where the
dealer should logically take over and
clarify the product through a demonstration.
Furthermore, we regard it as our
responsibility to inform those who
read the high fidelity publications
concerning the existence of our new
models and their various features.
This is one important way in which
we can serve those who are interested in the finer high fidelity components and who therefore need to
know what is on the market, in order
to visit a dealer intelligently, being
informed in advance concerning the
products they wish to see.
Since the Lab 80 is on the market,
and we believe you would want to
consider it if you were interested in
making a purchase, we are sure you
would want us not only to advertise
... but to explain it in the greatest
possible detail. This we are doing in
the present series of ads, and we
must continue to do so increasingly
as the season progresses. We want
an informed public, for everyone's
benefit.
Considering the above, and taking into account the difficult supply
situation, we would appreciate your
consideration of these alternatives,
assuming that you may be in the
market for a high fidelity system:
1. If you are interested in a Lab 80
(or have already ordered one) we
assure you that it will be shipped as
quickly as possible. However, there
will definitely be a delay-and you
will have to be unusually patient. If
you are willing to wait, we say without reservation that you will have a
superb record playing instrument.
2. If you cannot wait, do not order a
Lab 80, since this merely creates
pressure on yourself, the dealer and
ourselves. In this case, we would
strongly urge that you give careful
consideration to one of the other
three new Garrard models -most
particularly the Type A70, a topflight unit which has many performance features equal to those of the
Lab 80.
I cannot conclude without thanking you for your patience and understanding of this trying situation,
which has come about only because
the Garrard Laboratories are making the effort to provide a genuinely
unprecedented, totally excellent record playing unit.
Sincerely,
Leonard Carduner
President
British Industries Corp.
2
AUDIO
FEBRUARY, 1965
is also
the most advanced
fully automatic
record changing
THE LAB 80,
a most advanced
transcription
turntable/tone arm
combination...
(
for single records
L
the
arm slotcln
rlc<rcndre
he I,:Ib 80
or not it is preferable to play onry
single records on a turntable, has
If an interest in music is the reason
for your listening, the value of
automatic play can hardly be overstated. The al tonl:rtie shut -off
feature alone i, ii add ,c entire
been obviated. However. the
search for perfection among is'
ord handling methods continues_
This is the key to the acceptahil
itv of any automatic as a trc.,
peer of the finest single play unit-
!AB 80
$99.50
ÁT60 $59.50
nlinl
lor up to emit records)
l
After the lint reeeril.
studs itself off.
automatic
spindle system
unit ...
In order to appreciate the sure, gentle operation
of this automatic instrument, you must see it in action.
area of pleasin e to your enjoy
To begin play -mess the automent. But the problem has her,n
matic tai. At the end of the
to provide this connet-Men, e
record_ the arili aiii'.aes an ultra out impairing the distortion -fr-r
sensitiye.Tnal:noj trip--and the
performance demanded by modnext record dropsy quietly, cnshern music systems Today, with a
ïoned by iir.'Co reject the record_
fine Inn` :n-m 1:1- exemplified by
touch the tulfolmai is tai again. To
the dynamically' balanced. low.
pause. incas the manual tab. The
geliinetIV arm of the I al 80), the
arm tivill rise amyl remain susnlax mum variation in stylus
pended a safe '_ inch over the
i.,ressure between one record and
record. When you are ready to
a stack is a negligible 0.2 grams
resume Ier.acily whore° you left
(two- tenths of a gram).
off or at any other hand). simply
press the built -in isa ing control,
Therefore, the question of whether
and
The reason is
this rev 3lu`ionary
r11
'. h,stdupon
rrrlrr printiplrs?
Now. the same principles which
established Garrard as the preeminent name in automatics...
proven Ihrough literally millions
of playing hours...have been designed into the Lab SO spindly,
creating the i-ateat, most positive
device of its kind. The stack of
records is se,'urely supported on
three widely extended arms. The
arms retract and the next record
is released, gently sill Ixlsitiveln'
)-hen. during the entire perform :,n,e of the record. the tone arms
autoi'L absolutely free of the
matic nlechanisnl.
The automatic spindle arrangement
is only half of the story. The trip
nu,h:mi,ni is the other half -and
u ;ill. inll,ort:rnt -çirn'e it activate; the entire automatic operaion. At the toil of the record,
sold nnl before. the tone arm must
-
trial,('
the Irip
...butwith infrni-
losinral friction or drag. In the
Lab 80, this problem is brilliantly
solved. The trip assembly is
molded of llelrin'', the remarkable new Dupont "slippery" material. The tripping cycle works
through magnetic repulsion. eliminating mechanical contact. These
two principles. ingeniously combined for the first tune in art automatic record playing device, are
the answer of the Garrard engineers to the stringent requirements of ultra -sensitive cartridges,
allowing you to use the cartridge
of your choice, no matter how
light the tracking specifications
may be. All are compatible'
A short spindle is
provided for playing
single records,
TYPE A70 $84.50
MODEL 50 544.50
IMPORTANT READING:
New 32 page Comparator Guide. For complimentary copy,
write Garrard Div., British Industries Corp., Dept. GB-25, Port Washington,
Canadian inquiries to Chas. W. Pointon, Ltd., 66 Racine Road, Rexdale, Ontario. Territories other than U.S.A. and Canada to Garrard Engineering
Circle 103 on Reader Service Card
N.Y.
limited, Swindon, Wilts, England,
COMING
I
VVIAIMONARANNASIOW
Construction
A Calibrated Stereo Control. Raphael F. Ehat. A
stereo control unit which
incorporates the Bauer circuit for true stereo headphone listening, plus a separation ratio calibration circuit which enables measurement of actual separation
ratio.
Loudspeakers
Acoustic Resistance Damping for Loudspeakers. John
L. Grauer. A method of
achieving improved damping of dynamic loudspeakers, with resultant improved
performance.
Circuit Theory
A La Pie Mode. George
Fletcher Cooper. Description and discussion of the
7r -mode
class AB output
stage for transistor ampli-
fiers.
Profiles
Garrard Lab 80 Automatic Turntable
Fisher 600T Solid State
Stereo Receiver
Concord R -2000 Tape Recorder
In the February Issue
On the newsstands, at
your favorite audio
dealer's, or in your
own mailbox.
4
send questions to :
Joseph Giovanelli
2819 Newkirk Ave.
Brooklyn 26, N. Y.
Include stamped, self- addressed
envelope.
Amplifier Feedback Adjustment
filtered. What you must do is to place a
series combination of a resistor ami
capacitor across the switch contacts as,ociated with the commutator. Use a 200 ohm resistor, two watt, and a 0.02 µf capacitor, 600 vdc. This should eliminate
the noise burst.
Stereo Channel Balance Meter
Without a distortion meter, but
Q. I would like to build a stereo chanwith a CRO, VTVM, and source of sine
and square waves, how does one deter- nel balance meter using a 50 -0 -50 micro mine the value of the resistor and capac- ammeter, if such a project is practical,
itor required to give a desirable degree for use both at the amplifier outputs as
of feedback for any given amplifier? well as at the outputs of my preamplifier,
Typically, say, over 2 or 3 stages with designed to work into a high impedance.
Will you please suggest a suitable cirpush -pull output circuitry. A. G. Down cuit? John E. Kirkland, Jr., Knoxville,
ersgrove, Illinois.
Tennessee.
A. In order to find the proper resistor
A. I shall consider this question in two
and capacitor values, start off with a
resistor which gives the maximum feed- different ways. First, I will deal with the
back possible before the amplifier breaks condition in which the balancing is to
into oscillation. Then feed in some square take place at the outputs of your power
waves and try various capacitors until amplifier. There are three separate apthe best squarewave appearance is found. proaches by which balancing can be
When this capacitor has been installed, achieved at the amplifier output.
The first method is the simplest. It
it may be possible to increase the feedback still more. A further improvement consists of using two separate VU mein squarewave response may then be ters, or two VU meters combined in a
achieved by selecting another capacitor. single case, especially manufactured for
In any case, provide a 3- to 6 -db margin use as an aid to achieving stereo balance.
In this scheme, one VU meter is conso that the amplifier will not oscillate.
nected to the output of each power amplifier channel.
Rotator Noise
If the signal provided by the power
Q. I recently added an automatic roamplifier is insufficient to cause good
tator to my directional FM antenna. My meter pointer deflection, transformers
problem is that at the end of any degree must be used to increase the impedance
of rotation of the antenna I get a ter- in order to obtain a closer match between
rific burst of noise through the speakers the amplifier's output circuit and the
even when the volume control on the meter's input circuit. However, I do not
preamplifier is turned all the way down. recommend an exact impedance match
There is no noise from the speakers because the rectifier action of the meter
while the antenna is rotating. The noise may be reflected into the system as disoccurs only at the end of rotation when tortion. Use a transformer which will
the power to the rotator is cut off. The provide impedance correction to about
burst of noise is so loud as to be uncom- 100 ohms rather than the 600 ohms refortable. I have tried reversing the a.c. quired for an accurate match to a stanline plug of the rotator.
dard VU meter.
Can you suggest a method of eliminatThe second approach will allow you to
ing or reducing these noise bursts? make use of your present meter but neRobert E. Alleman, Monrovia, Cali- glect the zero center. Connect this meter
fornia.
from the "hot" lead of one channel to the
A. If you will open up your rotator "hot" lead of the other channel. Next,
control box, you will find a commutator feed a stereo signal into the system. A
arrangement which switches the primary pointer deflection means that there is a
voltage off after the antenna has arrived difference of potential between the two
at the proper compass heading. This is
the portion of the circuit which must be
(Continued on page 58)
Q.
AUDIO
FEBRUARY, 1965
How will an Olympus Energizer /Transducer
look in your home? Elegant, whatever your style.
Accustomed as we are to viewing the Olympus
in a
contemporary setting, it is revealing
to see here how comfortably it belongs among
the rich and carefully selected traditional furnishings
of an actual owner. This universal compatibility is
the result of
a
manufacturing philosophy
a
...
determination to handcraft components of such
enduring excellence that they are destined
to become heirlooms, passed on from one
generation to another. The photograph shows
only one Olympus of
Jiiiit_i
a
a
matched pair powered by
JBL solid state stereophonic
Energizer that is precisely matched to
the characteristics of the transducers.
At the foot of the stairs we see the new JBL Delphi,
an
equipment cabinet styled to complement
the Olympus, and in which this owner has
installed
a
Graphic Controller, JBL's
latest solid state
component. There
is a completely new
JBL catalog which
we will be happy to
send at your request.
JAMES
B. LANSING SOUND, INC.,
LOS ANGELES, CALIFORNIA
900'.9
World renowned for perfection in sound
Circle 105 on Reader Service Card
AUDIO
FEBRUARY, 1965
5
www.americanradiohistory.com
AmericanRadioHistory.Com
LETTERS
Stereo Volume Compression
SIR:
A few
Another exciting new
product from Acoustech
Full- range, stereo electrostatic
loudspeaker/solid -state
amplifier system
Two electrostatic loudspeakers
operating as true dipoles for enhanced stereo effect; designed,
developed, and produced under
the direction of Arthur A.
Janszen.
Frequency allocation for high
and low frequency reproducing
sections accomplished by four
solid state power amplifiers (two
one for woofer, one
per panel
for tweeter).
Fully stabilized system, complete
$1690 ($1699, West of
Rockies)
For more information, mail coupon
-
-
below
ACOUSTECH, INC. Dept. A -2,
139 Main St., Cambridge, Mass., 02142
FREE
Please send booklet "Why Solid State
Amplifiers Can Sound Better" and
full information on the Acoustech
amplifier system to
1
I.
speaker/
I
I
1
I
Name
Address
I
X
1
City
-
1
State_.
mom
CIRCLE
106
1
ZIP
ma
J
II flits to readers constructing a
"Low -Cost High- Performance Volume
Compressor" as described in your December 1964 issue. The circuit is fine for
mono use, but will tend to reduce stereo
separation if two such circuits are used
for stereo, because the two circuits will
independently try to equalize the levels
in the two channels. For example, if a
singer is heard mainly on the left channel, the left compressor will reduce his
level and thereby shift the singer's apparent location toward the center.
The solution is to compress both channels together, rather than each channel
separately. Thus the compression will reduce the total volume, but not the ratio
of left -to -right output. This is easily
done.
The circuit uses a Raysistor, which
consists of a small bulb and a photosensitive resistor such as a cadmium sulfide cell, mounted together in a single,
light-tight assembly. But the reader can
make a much more versatile unit by putting such an assembly together himself.
Getting back to the problem of keeping a constant left -to -right ratio while
controlling both stereo channels together,
all this requires is that the controlling
element, the cadmium sulfide cell, `see' not
only the bulb in its channel but also the
bulb in the other channel. This is done
by placing two bulbs and two cadmium
sulfide cells together, carefully insulating
their leads and then wrapping the entire assembly with reflective aluminum
foil and sealing it.
There are many variations on this
basic theme. One is to slightly modify
this arrangement so that each cadmium
sulfide cell sees the bulb in the other
channel a little better than it sees its
own. This has the rather unique arrangement of increasing the apparent stereo
spread! A loud singer in the left channel
thus causes the right channel to become
slightly weaker, thereby making the
singer seem even further left than he
really is.
Carefully inserting two more bulbs
and shielding each bulb, more or less,
from the cadmium sulfide cell in the
other channel, we get one more control
element. These bulbs can then be controlled independently from a battery or
d.c. source and a pair of potentiometers
near the favorite easy chair. This provides noiseless and humless remote control of volume and balance at little additional cost.
Finally, slightly altering the control
circuit and the position of the cadmium
sulfide cell in its circuit, we can get expansion as well as compression. This,
however, has to be done carefully to prevent regeneration in the system.
PETER A. STARK
519 East 86th St.
New York, N. Y.
Listener Preference Versus Reproducing
Fidelity
Mr. Rubenstein's letter commenting on
my article "live vs. recorded" concerts
brings to the fore one of the most important distinctions in high fidelity terminology : the difference between listener
preference and the evaluation of reproclueing fidelity.
It is possible to make a very poor
judgment of reproducing fidelity, either
honestly or by design, as was done in
connection with "live vs. recorded" concerts of the 1900's. Such errors of evalu-
ation are quite different from the evaluation of reproduced sound on the basis of
taste. An expression of "listener preference" at a live vs. recorded concert where
the live and reproduced sound were not
readily distinguishable would entail
praising or condemning both the live and
the reproduced sound.
The subject of psycho -acoustics is the
perception of sound, and not, as some
writers seem to think, listener preferences. Precisely because there are so
many factors that influence the way we
perceive sound, the evaluation of reproducing fidelity is aided tremendously by
having the original live sound on the
spot for comparison.
EDGAR VIELCHUR
Acoustic Research, Inc.
24 Thorndike Street
Cambridge, Mass.
Organ Oscillator Coil Source
Several readers of my recent paper,
"An Electronic Organ Design" have
queried me concerning a source of electronic organ oscillator coils. Another
reader, Mr. R. E. Pavelka, 1449 Rock way Ave., Lakewood, Ohio has recently
written one offering to supply such coils.
After examining and testing some samples, I can report that Mr. Pavelka's
coils are of excellent quality and reasonable in price. Readers wishing to obtain
such coils should contact Mr. Pavelka
directly at the address above.
WINTHROP S. PIKE
101 Leabrook Lane
Princeton, N. J.
Copyrights
SIR :
As I see it, the American Society of
Composers, Authors and Publishers
(Continued on page 57)
AUDIO
6
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FEBRUARY, 1965
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AUDIO
FEBRUARY, 1965
7
Ken Griffin: Love Letters in the Sand
LIGHT LIST[MNG
Chester Santon
Golden Boy (Original Broadway Cast)
Capitol SVAS 2124
Originality in musicals is not an everyday
occurrence these days. I recall seasons when
the spring months would come and go without
the appearance of fresh ideas such as those
found in "Golden Boy" at the start of the '64
season. If the originality shown in setting to
music Clifford Odets' famous story of a prizefighter is an omen for '64'65 on Broadway,
we have a good year ahead of us. "Golden
Boy" has been around for a long time, starting as a play back in 1937 when the Group
Theatre ran it for 248 performances with a
cast that later went on to wide fame in the
theatre and motion pictures. The story reached
a truly national audience In 1939 with William Holden getting his first big break in pictures in the title role. John Garfield furthered
his career significantly in the New York revival of the play in 1952. The harshly realistic picture of the boxing world in the original
has been given a pungent new twist in the
1964 musical. To make the struggle of the
young prizefighter as up to date as possible,
the plot has been changed so that a Negro
now occupies the central role. The producers
of the show make no bones of the fact that
the part was tailored for the specific talents
of Sammy Davis, the present lead. A large
supporting cast headed by Paula Wayne and
Billy Daniels lends total credibility to every
scene dealing with the hero's rise and fall in
his tragic ring career. The music of Charles
Strouse and the lyrics of Lee Adams provide
an insight into environment that would do
credit to some of the past great shows with
a New York locale. The early scenes that find
Sammy Davis still up in Harlem have the
bite and penetration of the best moments in
"West Side Story." "Gimme Some" and "Don't
Forget One Hundred and Twenty- seventh
Street" are outstanding examples of trenchant social commentary. Davis sets a hard
pace and maintains it throughout the show
with Billy Daniels keeping right up with him
as his oily and sinister manager. You get an
impression mighty early in this album that
the key members of this aren't just play acting. All hands involved in this production rate
a nod for a job well done.
Ben Franklin in Paris (Original Broadway
Cast)
Capitol SVAS 2191
Who says old geezers aren't getting their
share of attention in this year's Broadway
musicals ? In mounting for the stage this story
of Ben Franklin's intrigues in Europe when
he was pushing seventy, the producers are
showing little concern for the tradition that
a musical's main character should be no more
than sixty -five in age. George W. George and
Frank Granat, who recently made their producing debut with "Dylan" and "Any Wednesday" may have tackled this story for their
first musical to demonstrate their daring -or
simply to point up the absence of sufficient
youthful male stars on the Main Stem. They
have made one concession to the demands of
show business. Although Robert Preston is
decked out in the hairdo and spectacles of the
older Franklin, his resonant voice needs no
assistance to fill the theatre. Preston is pretty
much the whole show on this recording just
as he is on stage. He appears to have a fine
time bringing out some of the lesser -known
facets of Franklin's career as a diplomat at
the time when the American colonies had just
declared their independence from England.
To the degree that the listener can work up
an interest in Franklin's efforts to line up
French and Spanish support for the colonies,
this is probably a great idea for a show. "Ben
Franklin in Paris" has already whetted my
curiosity to see what Broadway can do in setting to music the signing of the Magna Carta
or Napoleon's decision to add another country
to his empire. It must be noted immediately
that such tantalizing morsels in Broadway's
future probably won't be clever enough to secure the services of a leading lady as intriguing as this production's Ulla Sallert. To
play the part of the Comtesse Diane de Vobrillac, Franklin's lady friend at the court of
Louis of France, Miss Sallert has come all the
way from Sweden, where in private life she
happens to be the Baroness Von Lampe. In
her public career, Ulla Sallert is Scandinavia's leading musical comedy star, having appeared in the Stockholm productions of most
of our leading musicals. Her foreign accent,
backed by a genuinely trained singing voice,
is a perfect foil for the Fourth of July inflection of Robert Preston's Franklin.
In the packaging of this album Capitol
Records appeared to be aware of the fact that
the first side of this disc is somewhat less
interesting than the second. To occupy the
listener's thoughts until the score takes on
some sparkle midway through the record,
Capitol provides a seventeen -page souvenir
program similar to those sold at exorbitant
profit in the lobby of the theatre. By this
time one has examined all the photographs
and pored through the biographies of the
players, designers, wigmakers etc., the show
begins to come to life as a chorus of carefree
monks at a vineyard bounces through "Hic
Haec Hoc." In a further reduction of reserve,
Franklin trades drinking toasts with the
Spanish ambassador in "God Bless the Human
Elbow." Ben's proposal of marriage to Diane
is backed by two pleasant songs and the show
closes with a patriotic soliloquy that has
Franklin speculating on the importance of
liberty to Americans 200 years later.
Harold Rome's Gallery
Columbia KS 6691
It's not easy to forecast what the mail will
bring these days in the way of records for
review. Here's a difficult -to- catalog album by
the composer of Broadway shows such as
"Call Me Mister," "Fanny" and "Wish You
Were Here" that deals with the guy's paintings as much as it does with his music. In
between his normal assignments, composer
Harold Rome has been painting for his own
pleasure and relaxation since 1948. Now,
through the generosity of Columbia Records,
he has lived to see the day when a collection
of his modern paintings in full color adorns
the two inner pages of a hinged record album.
The paintings illustrate the collection of
songs found in the grooves of the accompanying record. With a clear choice before me, I
found a bit more interest in Rome's paintings
than I did in the songs delivered by Betty
Garrett, Jack Haskell, Rose Marie Jun and
Rome himself. Some of the titles -My Long
Ago, The Wolf That Swallowed Red Riding
Hood, Half- Forgotten Teddy Bear and Shake
Hands, Dear Mrs. Cow -would indicate Rome's
reluctance to abandon thoughts of childhood.
The songs, "The Critics," "Art in the Night"
and "The Audience" take up matters that are
part of a composer -painter's shop talk. Examined from any angle, most listeners will he
inclined to put down this release as a curio
that fills in a little extra background on the
private life of one of our leading Broadway
tunesmiths. Purists in reproduction will be
pleased to learn that Columbia's registration
of the paintings' colors covers with full fidelity a wide range of interesting hues.
Columbia CS 9043
In selecting material recorded solely in the
mono medium for reissue as "processed"
stereo, most of the disc companies have favored original cast albums and other vocal
items that cannot be duplicated today or
samplings of the orchestral work of conductors no longer available to practice their art.
By now, most of us are familiar with rechanneled stereo in some form of vocal or
orchestral music. This Columbia release happens to be my first opportunity to sample a
mono Hammond organ recording that's been
converted to stereo. It may be that this type
of organ lends itself to reprocessing more
readily than other musical material. Whatever the reason, Ken Griffin fans will be
pleased to know that a fine job of behind-thescenes workmanship has gone into this rerelease of a best- selling artist. Griffin, far
more than the average organist in the record
catalogs today, did everything possible to
make the melodic line of a tune clear and
concise to the listener. He belonged to a period that didn't believe in cluttering a song
with personal embellishment and the result is
still refreshing today. The selections heard in
this album fall into two groups : solo organ
and organ with a very pronounced rhythm
accompaniment. I prefer those tunes in this
collection of favorite standbys where the organ alone holds the spotlight. The artificial
separation is more convincing when the beat
is heavy but the atmosphere of the skating
rink may be too much for some tastes.
The Four Lads: Songs of World War
I
United Artists 6399
What is there about the songs of World
War I that makes them belie their age? Most
of them seem about twenty or thirty years old
yet the reason they're being revived these
days is the fiftieth anniversary of the beginning of that conflict. Recalling the era in this
album is the versatile quartet known as the
Four Lads. This group has been fairly active
in the past four years on the Kapp, Dot and
Columbia labels. In this, their second release
for United Artists, the quartet is assisted by
an unidentified ensemble of girl's voices in
arrangements that are either perky or sentimental in such standbys of another generation
as How 'Ya Gonna Keep 'Em Down on the
Farm ?, Madelas, My Buddy and Roses of
Picardy. Producer Jack Gold's closeup of the
four featured voices will be considered an
asset by any codger trying to follow half remembered lyrics of the period.
Fiddler on the Roof (Original Broadway Cast)
RCA Victor LSO 1093
With the release of the Zero Mostel show,
"Fiddler on the Roof," the new Broadway
season can be considered underway in recording studios as well as on the Main Stem. It
is difficult to forecast how vast an impression
this musical based on tales of Sholem Aleichen
is going to make in disc form. Much will depend on the amount of background knowledge
of the story's locale the home listener will
have at his command when he first puts on
the record. Far more than the average RCA
original cast recording, this musical calls ont
for the scenes-from -the -show deluxe packaging
that other record companies feature in their
top Broadway albums. The non -hep listener
would then find it easier to follow the placid
story of Tevye, a poor dairyman with five
daughters to marry off in a tiny isolated Jewish village in Tsarist Russia. Lyricist Sheldon
Harnick and composer Jerry Bock -whose
past shows include "Morello," "Tenderloin"
and "She Loves Me" -have obviously done
their homework in researching pertinent folk
music of the period in devising their sympathetic score. Of the entire cast, Zero Mostel
appears the least handicapped by the absence
of the visual element in putting over the
songs and chants of a society that may seem
a bit exotic and remote to the average show goer. The sound on the disc is acceptable ; the
miking is closer than average for a studio as
large as Webster Hall and the stereo illusion
is confined to across -the -stage movement on
the part of the singers.
Æ
AUDIO
FEBRUARY, 1965
Airs fire-year speaker warrantee
One of these guarantee cards has been on the back of every AR speaker since 1961, w'len AR extended
its one -year speaker guarantee retroactively to five years.
INC.
aualellllt>ZÉc
This .speaker system carries a fire -year guarantee cm-wring coat of replacing
defe,tite materials, labor, and freight to and from our factory, under the
following provisions.
The attached guarantee card should 1w filled out and returned to the factory
within In days of date of purchase.
to Cm of Dienonny Under no circumstances should you try to open the
cabinet or remove the speakers. If a defect is suspected, the best way to
ascertain whether the speaker system is at fault (and not the amplifier,
pickup cartridge, or some other part of the sound system) is to bring it to
your AR desltr and have him check it in comparison with a stock unit of
the same model. If your speaker appears to be defective on this check,
your dealer will request an "Authorized Return" label from us and return
the speaker system for repair. Make sure a description of the trouble
symptoms is sent to us.
If you have no local AR dealer, do not return the speaker system direct
without prior authorization, When you have established as best you can that
your speaker system actually is defective, write to us requesting an
"Authorized Return" label.
At the same time:
1.
State the symptoms clearly. This will help us to expedite the repair.
know if you have kept all cardboard parts of the original shipping
carton, or need a new one. AR speaker systems, which are very heavy for
their size, must be shipped in cartons designed for them; otherwise,
damage to the cabinet in shipment is possible.
2. Let us
r
kTESTED
BY
1
you
L.i-a
D
Model No.
lIli
I
78481
r. y,rt±,
Irr
:iK 2a
MEo
waLIWT
.
Date
Name
Address
City
State
Date of Purchase
Dealer's Name
Address
I
e
that it has never been necessary for us to make good on our guarantee. It has been
necessary. During the five years that AR -2a's have been sold, 671* of them have either been returned
under guarantee to the AR plant (we reimbursed freight charges, of course) or repaired at one of our
stations in New York, Los Angeles, or San Francisco. This is less than nine-tenths of one per cent of the
78,481 AR -2a's manufactured to date, an outstanding record.
We wish we could say
All AR speakers, including the new low-cost AR -4 ($51 to $57), carry this five -year guarantee. AR turntables
are guaranteed for one year under the same conditions.
*In addition, 38 speakers were returned with no defects, and freight charges were not reimbursed; 53 returned speakers
were judged to have been subjected to gross abuse (such as dropping or plugging in to the 110V outlet), and the owners
were charged for both repair and freight.
We expect the return rate of the AR -tax (new version of the AR -2a with improved mid -range speaker) to be even lower.
ACOUSTIC RESEARCH, INC.,
24 Thorndike St .,
Cambridge, Mass. 02141
Circle 109 on Reader Service Card
AUDIO
9
FEBRUARY, 1965
www.americanradiohistory.com
AmericanRadioHistory.Com
of our apartment house to the incinerator once every week for years and
years. I've just looked at it, with new
curiosity
hadn't given a thought to
its origin for I don't know how long.
Well, it has a big AR on the side, I see.
And on the back, against the wall, I discovered the legend "AR 2 ". That was
one of the earliest AR 2's ever shipped
out.
Anybody want an antique waste
-I
AUDIO ETC.
Edward Tatnall Canby
basket?
AUDITIES
E What
a Waste!
I've hit upon a new and, to me, highly
satisfactory way of rating the hi -fi
speaker manufacturers without intruding
upon the proper functions of our
"Equipment Profile" pages. It has to do
with my enormous need for waste
baskets.
You see, I am the victim of much
well- intended junk mail, both musical
and hi -fi, and somehow or other it must
be disposed of. No ordinary waste basket
is of the slightest use. Big, industrial
waste baskets are too heavy for my maid
to carry and if you push'em around they
scrape up the floor something terrible.
So I use cardboard cartons. Not ordinary cartons but those superbly engineered cartons in which our manufacturers ship ready -assembled speaker systems. As is well known, they come in all
sorts of convenient sizes. Just take out
a couple of cubic yards of inner packing
those tricky side -pieces bent like angle
irons, the bottom platforms of eight or
ten layers of corrugated board stuck
together, plus feet (I save these for future
use, as space allows), the cardboard top
plates, the side plates, the under plates;
also vast masses of waxed paper and /or
thin plastic sheeting, assorted instruction books, flyers, guarantee cards, little
bags full of screws and bolts, envelopes
containing rubber -felt feet to stick on
the speaker, folders full of lay -out plans
and wiring diagrams, sheetsful of dealers' addresses and service stations `round
the world, large warning posters saying
DO NOT
in glaring red. Plus, probably, on top of it all, one of those
unctuous greeting cards that wheezes out
"Congratulations! on having bought the
Finest Speaker Ever Made." Ugh.
Last but not least, remove the speaker
itself, and dispose of same. It is beside
the point.
Then tackle the remaining cardboard.
The big problem is to get the top flaps
off. No use trying scissors. Nor metal
snips. Nor garden twig clippers. I've
tried `em all. Razors help but you're
likely to slice a finger off and you'll find
you can only eut through about half a
layer in each side. Maybe a machete
would be best; but I use my good arms.
And fists. Just grab a flap manually
...
(having removed your coat, tie and perhaps shirt), brace yourself with both
feet and PULL hard. The flap tears,
about an inch. Rest a bit, and pull again.
The flap tears sidewise in half, leaving
most of itself still attached....
When all is said ( cursing and swearing), and all is done, you have yourself
a really first rate waste basket, big
enough to be in tune with our times' mail
(and newspapers and record wrappings
and what -not), and yet light enough to
carry when full, or to slide o'er the
newly -waxed floor, all the way from den
to incinerator. You can even bump it
safely down the stairs.
Well, the speaker makers don't all do
the same sort of job for me in providing
quality waste baskets. I dearly hate to
have to say so, but that reputable firm,
E -V, let me down a bit recently when I
received a pair of E-V Two speakers.
The cardboard cartons were a bit bigger
than I'd expected and I jumped at them.
But, alas, they turned out to be too
flimsy. The sides quaked, the tops sagged
in and when I lifted one of them, full
of rubbish to dump in my incinerator,
the bottom fell out. What a mess! E -V
is now on my waste paper basket black
list.
(N. B. The E -V Two's arrived in
perfect condition. But that, as I say, is
quite beside the point.)
For me, then, one of the happiest results of the recent trend towards a new
size in "bookshelf" speakers is that I'm
now collecting a whole new fleet of waste
paper baskets of a wonderfully convenient size, just right for kitchen, front
parlor or side room where space is a bit
limited but waste paper abounds. Now,
on my long -term list, the finest firm of
all is Acoustic Research, Inc. Never
mind the speakers they make. Unimportant. What counts is the quality of
their cartonry, which is no less than
superb! I just picked up two AR -4's and
their twin cartons are absolutely perfect
as waste containers. Just the right feel
and give, the proper structural elasticity
combined with rigidity (if you see what
I mean); and the top flaps tore off so
easily I figured they were pre- stressed
and scored, for my special convenience.
Next to my desk in the city I have the
oldest carton of them all, which has been
pulled out and slid down the tiled hall
2. The Computer's Share
As an old fashioned humanist, i.e. a
person who thinks people are more important than things, I am constantly
amused (and made thoughtful) by the
computer's attempts to take over just a
bit more than its reasonable share of
human ways. I guess it's natural for it
to do so (or for us to tell it to), considering what astonishing things are
now possible with such machinery. The
picture admittedly changes almost day
by day and there isn't an end in sight.
Nevertheless, there's always somebody,
there's always some computer or other,
that goes too far, testing the future and
coming off second best.
Sometimes the computer looks downright silly, though it isn't. It's just being
narrowly reasonable, within the framework of its instructions from people.
We may very well compare a human
being to a computer, but not the other
way around. Yes, we are computers and
marvelous ones too -whether thought up
by an ingenious Creator or, even more
ingeniously, self -made out of living tissue that "just growed" that way in
response to the peculiar laws that govern
our cosmos. We do compute beyond compare. We can do many things faster and
better, taking in more factors, than any
man -constructed computer will ever be
likely to. And so one of the things we
ought to do more of is to discriminate
between computing and thinking.
It isn't easy. Because thinking is, indeed, a form of computing and vice
versa. You really can't draw any theoretical line between them. Yes, computers
do "think." So did the first adding machine and before it the abacus. Within
limits, of course. Also beyond some limits,
of the sort that hold back or stymie the
human computer. But nowadays we seem
to feel that the limits are off, or ought to
be. I doubt it. I'm a humanist, as I say.
Tools
The best thing is to look at the whole
business pragmatically, that is from a
practical (i.e. human) point of view. The
proper use for all computers, as anybody
can see, is as tools. A tool is a figurative
lever, which doesn't work by itself but
rather as an aid to human workings.
Never forget that. So far, only human
AUDIO
10
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
A SMALL SIZE MICROPHONE
MATCHING THE GRANDIOSE SOUND
The wide -range sound of organ music presents a formidable challenge to a n y microphone. Yet look below.
The response curve you see below is n o t that of a
condenser microphone, nor that of a laboratory prototype. It is the actual final inspection curve of a random picked production -model.')
MD
211
Dynamic Studio Microphone
shown in actual size, at the right. The curve of this omnidirectional microphone spans more than nine octaves.
-
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This quality
SENNHEISER quality
and every MD 211 by a rigorous, comprehensive series
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The MD 211 is designed for professional applications in
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For further details, including full technical specifications
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of quality
r
r
*
Circle 110 on Reader Service Card
AUDIO
FEBRUARY, 1965
11
JUST OFF THE PRODUCTION LINES!
FIRST NEW STUDIO
may be used in extremely low -level circuitry without noise or hum pick -up. Zero
PRODUCTS FROM ALTEC'S insertion loss. 68A LOW PASS FILTER
AUDIO CONTROLS DIVISION is 3 "H x 2'/4 "W x 51/2"D. Price $115.00
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ALTEC 60A MICROPHONE EQUALIZER
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provides up to 12 db
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combines the 68A and 69A for rack
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cycles and
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tinuously at 85 °C without derating. Frequency Response: ±0.5 db, 20-20,000 cps.
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beings have learnt to use them, and thus
we define ourselves. Tool-users.
A tool has two qualities 1. It derives
its motivation, physical or mental, fro111
a human being, whether directly, like the
mechanical typewriter I'm using, or indirectly, as the horse pulls the plow; 2.
a tool necessarily does its task better
than a human being, unaided. Like, say,
a screw driven by a screwdriver. Or my
200 -year -old grandfather clock that computes the time continuously for eight
days running.
(You might say that 3. some tools,
under proper direction, can do things
altogether beyond human ability. But if
you'll stop a moment and think it out,
you'll see that this is merely 2. carried
to a greater degree. A tool is a tool,)
There's nothing very new about all
these ideas. Computers, in this sense,
aren't new; they're merely advanced. Unprecedently quick tools, because at last
they are freed from the inertia of mass
and the annoyance of gravity. And
hugely capacious tools, because their
memory devices are so small ( though not
half as small as our own). Unprece:
dented, but still-tools.
When is a tool not a tool? Only when
it starts to act like a human being, which
is undesirable and against our best interests. We are still at the top of the
Creation heap, remember, and for us all
things are tools. If not. they work for
their own purposes, oblivious of us from
the word go, then the Age of the Tool
is over and, for that matter, so is the
Age of Man. And thus we want to be
rather careful as to how we rate our
new tools in respect to our own computing abilities. We'd better, or else.
The trouble is that some of us, in spite
of all this, expect our computers to think
for themselves in ways that aren't practical and are unwise too, what with
millions of perfectly good human brain computers waiting around, looking for a
proper education followed by a respectable job. Nobody in his right mind
would suggest that the computer isn't
enormously useful in all its ramifications. But too much computer thinking,
still, can reduce the computer- humanbeing relationship to a shambles. Nobody
in his best mind should degrade the
human computer as some people do with
the best of intentions. The two systems
must learn to work together, meshed for
greatest usefulness-to us. Not to the
computer.
Luckily, most of the examples of current computeritis turn out humorously,
because a computer trying to act like a
man and not succeeding usually makes a
dizzy fool of itself. Gives us a nicely
secure sense of our own very reasonable
hum an-ness
!
Old Lady
For instance, I suppose you've heard
(Continued on page 65)
Circle 111 on Reader Service Card
12
AUDIO
FEBRUARY, 1965
t
With the new Royal Grenadier
You can turn down the sound
You can turn up the sound
You can sit to the left of it
You can sit to the right of it
1. 15" mass loaded woofer with floating
suspension and 4" voice coil.
2. Sound absorbent rear loading.
3. Die-cast mid frequency -high frequency
4.
full dispersion acoustic lens.
Hand rubbed satin walnut finish.
5. Imported marble.
6. Ultra -sonic domed tweeter.
7. Full presence mid range direct radiator.
8. Exclusive non -resonant rigidized
heptagonal sonic column.
World's largest (18 lbs.) speaker
ceramic magnet structure.
10. Front loaded Horn -360° aperture throat.
31. Complete symmetry of design with
terminals concealed underneath.
12. Dimensions: height 29"
diameter 22 ".
9.
-
Patents Pending
You can examine it
You can sit behind it
É EMPIRE
1W
CREATORS OF THE WORLD'S MOST PERFECT
SPEAKER SYSTEMS. FOR A SOUND
DEMONSTRATION GO 'ROUND TO YOUR DEALER
OR WRITE FOR COMPLETE COLOR BROCHURE.
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EXPORT: EMEC, PLAINVIEW, LI, NY
CANADA: EMPIRE SCIENTIFIC CORP LTD
1476 EGLINGTO\ \VEST, TORONTO
And you can say so much about it
Circle 108 on Reader Service Card
AUDIO
FEBRUARY, 1965
13
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amour
MUSIC
Harold Lawrence
Muzak orchestra, writes Russell Baker,
"is not that its repertory is lugubrious,
its instruments cloyed with honey, and
its musicians in deep melancholia. The
point is that, good or bad, it abridges
the priceless human right not to be entertained. There must be millions of shoppers (for instance) who do not want to
contend with `The Skater's Waltz' while
pricing peanut butter."
Muzak
-
The Music Goes 'Round and 'Round
A Look at the Background Music Business
In his December 15th column in The
New York Times, Russell Baker decried
the mounting number of electronic as-
saults on our privacy. His article was
prompted by the fact that walkie-watchie
television will be introduced this fall. As
you might have guessed, walkie-watchie
TV is a small battery-operated transistorized receiver which can be slung
around the neck and carried everywhere.
It is, Baker points out, "only one gun
in the massive entertainment barrage"
launched against the American people.
Many of these guns are manned by operators of background music. According
to a recent survey, 60 million Americans
are exposed to background music daily,
twice the number as 10 years ago. Sales
of this music were $45 million in 1963,
with the lion's share going to Muzak, a
division of Wrather Corporation. Muzak
and its imitators in the piped -in music
business have made it possible to hear
music virtually all our waking hours.
Loudspeakers are everywhere : underwater in specially wired swimming pools,
above the clouds in jet airliners, even in
space capsules.
Nowadays we can expect to hear tunes
like "You're the Cream in my Coffee" in
hotel Breakfast Rooms, "It's Gonna Be
a Great Day" in elevators, "Whistle
While You Work" in factories, "Abide
With Me" in mortuaries, or "Jingle
Jangle Jingle" in savings banks. It
would seem as if, as Time magazine put
it, "the total musication of America is by
now almost complete."
Not so, say the purveyors of background music. There are still many new
worlds to conquer. Ripe for attack is the
office where, until recently, telephones
typewriters mimeograph machines and
human voices have dominated the aural
atmosphere. Efficiency experts have come
around to the opinion that "background
music boosts morale and picks up sagging spirits when the morning and afternoon doldrums set in and mental fatigue
threatens to take over." (Modern Offlice
Procedures magazine). When boredom,
and the noise of its newly installed computer system, began to endanger morale
at the American Express Company,
Muzak was called in. A Wall Street firm,
Walston & Co., introduced Muzak into
its offices to improve the surroundings.
"A brokerage house is not known for being one of the quietest places in the
world. The piped-in music primarily
overrides background noises, particularly
in the back room," commented the company's senior vice -president. To relieve
the monotony of transcribing letters
from a dictaphone, Edison Voicewriter
brought out the Serenader. The new unit
consists of a "headset with two earphones, one for transcribed dictation and
the other for music transmitted through
leased telephone wires."
Selecting music for offices, hospitals
and other public places is a serious business, according to Donald M. O'Neill,
Muzak's Program Director. From its 30
years of experience, Muzak has learned
that jazz, solo instrumental music, vocals,
everything in a minor key, and anything
that lasts more than 3 minutes are undesirable. O'Neill's 35 arrangers and 10
musicologists work towards an unobtrusive sound that will stimulate, but not
excite; soothe, but not put to sleep. Dynamic range is cut in half by Muzak's
engineers : instead of the usual 50 db engraved on most discs, its recordings are
held down to a maximum of 25. Instrumentation varies according to the locale :
"In an office, where it is quieter," O'Neill
explains, "you can be more subtle with
your music, more restrained. But both
(office and factory) are given programs
that fit our `mood stimulus chart.' Since
workers usually start off the day with a
smile [No comment. Editor], sag in midmorning, pick up a little at the thought
of knocking off for lunch, then undergo
a similar mid -afternoon droop, the music
must be keyed to combat these curves."
The chief objection to the typical
Is
Music Is Muzak
But do these millions really exist?
Based on the evidence we can gather,
there seems to be no groundswell of
opinion against this invasion of sonic
ooze. Piped -in music may be "pallid pap
that will cause all our musical teeth to
fall out," as Helmut Blume, the acting
dean of music at Montreal's McGill University maintains, but most people dbn't
seem to mind it a bit. To a Muzak man
in Los Angeles, "the nut who complains
about music is the same one who bitches
about the office being too hot or too cold
and a thousand other things."
The "nut" who attacks background
music is probably the kind of man who
would hail a cab, get in, announce his
destination, and, hearing music blaring
out of a transistor radio on the dashboard, tell the driver : "Would you mind
turning that thing off, please?" It's
a risky question. Some drivers respond
quickly, twist the dial and say, "I don't
know why I bother to have it on; I
wasn't listening to it anyway." Others
just reduce the volume a decibel or two.
Some argue. A passenger recently received this dressing down from his driver : "Look, I'm a Hungarian refugee.
This is a free country, isn't it? Are you
trying to dictate to me? I fought the
secret police in Budapest during the
Revolution to get away from just such
oppression." The embarrassed passenger
could do little more than apologize,
plead a splitting headache, and mutter
something about having read a city ordnance forbidding hacks from playing
radios when passengers are aboard.
When we are not being worked over by
permanent background -music installations, chances are that mobile b.m. transmitters using small transistor radios will
molest us on streets, beaches, country
lanes, museums, subways and buses. The
transistor-radio player, however, suffered
a legal setback in Philadelphia last December 21st when a grand jury refused
to indict a history professor at La Salle,
accused of hitting a woman with a transistor radio that he thought she was playing too loud on a bus. "The professor
said he became angry when the woman
turned up the radio's volume, and even
moved to a seat closer to him. As he
sought to seize the radio, it struck the
woman on the head." (New York Times) .
,
AUDIO
14
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AmericanRadioHistory.Com
FEBRUARY, 1965
VILLAIN
CULPRIT
Tubed components are doomed.
It is now common knowledge
among hi -fi engineers that tubes
and output transformers play a
major role in creating distortion.
Why transistor components are
better. Transistor units produce
better frequency response
(cleaner, more "transparent"
sound) because they don't use
output transformers. Transistors
are the best switching devices
known to man, give better response to sounds of very short
duration. Speakers are coupled
directly to the output transistors,
giving you crisp, solid bass.
Tubed receivers require realignment at least every other year.
Transistors simply do not age
... and they run cool.
Why invest in obsolescence? As
you approach the extremely important purchase of your next
stereo system, bear in mind that
the very finest tubed equipment
will soon be hopelessly obsolete.
Harman -Kardon, possessing the
industry's longest, most extensive experience in solid -state
audio design, is and will remain
many years ahead of the field.
The industry's only all- transistor
line. While an occasional solid state component has appeared
in other lines, only Harman Kardon now offers the fabulous
wide -open sound quality of complete transistorization throughout its entire line
.
only
Harman -Kardon has advanced
.
.
to the point of going completely
out of the tubed -equipment business. Not even a nuvistor tube
remains to mar the 100% solid state sound of every Harman Kardon instrument.
Now, transistor economy. The
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FM stereo receivers (shown below), priced down with the most
popular tubed units, give you
Sound Unbound without the old
price penalty of transistor
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When you hear these magnificent instruments, you will never
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tubed equipment.
Harman- Kardon Stratophonic FM Stereo Receivers...
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MODEL SR300, 36 watts IHFM music
power. The best news yet for music
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power. All the front -panel convenience
controls of the SR900, and most of its
fantastic performance at every power
level with minimum distortion. Price $389.*
MODEL SR900, 75 watts IHFM music
power. Hailed by Audio (October 1964,
before the SR600 and SR300 came out)
as "the only component -quality all -transistor receiver we know of." Price $469.*
*Prices slightly higher in the West. Enclosures optional.
harman kardon
Philadelphia, Pa. 19132
A subsidiary of The Jerrold Corporation
THE LEADER IN SOLID -STATE HIGH - FIDELITY COMPONENTS
Circle 112 on Reader Service Card
AUDIO
FEBRUARY, 1965
15
EDITOR'S REVIEW
THE CASE OF THE CROAKING LOVEBIRD
pICTURE if YOU WILL a suitor about to suit. A tender
look on his face. A tender look on her face. James
Garner and Julie Andrews. He opens his mouth to
speak and out comes a series of sounds which would
undoubtedly please and thrill almost any female
frog!
A short time ago we took ourselves et al to the local
cinema to look at and hear what was billed as one of
the ten best pictures of 1964, The Americanization of
Emily. And it is a very fine movie. But the sound we
heard, oh my that wouldn't have won a prize for the
best of anything.
What should have been a soft, thrilling sound turned
out to be a raspy croak. Frog -like. (Not that we dislike frogs or frog sounds. In fact we do like frogs.
Especially their legs.) Hardly an appropriate sound
for the visual presentation. Incongruous in fact. It
destroyed the scene for us.
This experience started us thinking about the
quality of sound in movie houses. Strangely enough we
had not thought much about this facet of the "sound
picture." After all movies are an intrinsic part of our
childhood. One always went to the movies. And we
discussed the movies. Not the sound quality. Hardly
even the picture quality. Just what happened.
In previous Editorials we did mention sound quality
in "live" theatres. Because the contrast between live
performers and poor sound re- enforcement is immediately obvious. And most "live" theatres we have
attended have pretty poor re- enforcement systems. We
could never understand why a performer would permit his presentation to be limited by a poor sound systm. Perhaps performers are so busy concentrating on
their performance that they are unaware of what
the final projection is like. You'd think their best
friends would tell them.
Of course it is understandable that movie theatre
sound systems would not be questioned. After all
weren't they the daddies of all the sound re- enforcement systems used today ? Before "hi fi" and all the
mutations and combinations we listen to in our highly
"soundized" world, we were listening to the sound of
the movies. And who would question a daddy?
But now we had been forced to question. We had to
find out whether this experience was the rare bird, or
whether "daddy" hadn't kept up with the times. Our
hearing tastes, collectively, have become much more
sophisticated. We no longer tolerate the sound quality
our "forefathers" found wondrous. Just as we no
longer tolerate, collectively, the visual styles of the
twenties.
The question, then, is whether movie sound, collectively, has remained relatively static.
The answer is no.
After much looking, listening, and thinking, we
determined to our satisfaction that movie theatres
generally have good sound re- enforcement systems. Not
perfect. Not "hi-fi." But capable of producing voice
quality fully believable as accompaniment to celluloid
people. And music that sounds like music. We didn't
uncover a frog in a carload.
-
16
Not that it can't be improved. And a lot. But the
quality is definitely an the upper rungs, in comparison
with the all the other sound re- enforcement systems
we are subject to. For example take television. Ugh l
We can consider the case of the croaking lovebird
as having been solved. It was a rare bird, croaked by
a defective system.
PLUG -INS PLEASE
We note, in our review of a solid-state amplifier in
this issue, the use of plug-in printed circuit boards.
The value of plug ins relates to the ease with which
the consumer might get them serviced. All a serviceman need do to determine the area of malfunction is
plug in a known good board. And send the customer
on his way if that does the job. Then, rather than get
involved in the vagaries of troubleshooting these
boards, he could just send it on to the manufacturer
for repair. The manufacturer, with test jigs and a
variety of expensive test instruments, plus the intimate
knowledge of how they are made, would be able to
service them easily and economically. After all, the
manufacturer would be servicing relatively large
numbers of the same board. Thus a flat, and somewhat
small, fee could be charged to repair the board and
service to the consumer would be very much quicker
than under present procedures. Also, in many instances
the quality of service would be vastly improved. The
manufacturer would bring the boards up to manufacturing specifications, which is not too likely in the
ordinary service shop.
It should also be advantageous for the serviceman.
He would stock plug-in boards rather than a large
amount of parts. And troubleshooting would be the
simplest imaginable procedure.
This "black box" approach was, and is, used very
successfully in the military services. For the very
reasons we mentioned : servicing speeded, and economies effected. Of course this approach is very hard to
apply when equipment is very complex. Fortunately
audio equipment (including tuners) is not complex
in that sense. Transistors are making it even less complex.
Now if only manufacturers would accept this black
box concept... .
CORRECTIONS
The following minor corrections were noted by
Wayne B. Denny, author of "Matrixing amplifier for
2- channel stereo signals" which appeared in our
January 1965 issue
In Fig.
:
the legend should read
gain of difference signal (1 + k)
gain of sum signal
(1
Also in Fig. 2 the two phase inverters to the left in the
diagram should be designated P and not R. And the
output signal from the top left phase inverter should
be (1 +k) (R
and not (L
Finally, in Table
II, the top value of (R ld) should read B C and
not B + C.
2
k)
L)
R).
AUDIO
FEBRUARY, 1965
(V -15 AME -1 ELLIPTICAL STYLUS)
NATURAL SOUND BEGINS WITH PICKERING
Whether you own a record changer, automatic turntable, or a professional type manual turntable
Pickering has engineered the RIGHT V -15 pickup for you. Each of these applications requires a
cartridge with specific characteristics and specifications to produce the maximum in NATURAL
SOUND that is possible from the record playing equipment and other components in your system.
If it's RECORD CHANGER application, where high output and heavier tracking forces are
required try the V -15
AC -1 Most of you, no doubt are tracking lighter on the late model
Or if a professional type MANUAL
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AT-1
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V-15 AME -1 All of these pickups are radically different from any other cartridge. You can see
the difference. You can hear the difference. Pick up a V-15. Note its light weight -only 5 grams.
Perfect for low mass tone arm systems. Now, see how Pickering's exclusive "Floating Stylus"
and patented replaceable V -Guard assembly protects your record and diamond as it plays.
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AUDIO
FEBRUARY, 1965
17
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AUDIO
18
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FEBRUARY, 1965
Characteristics of Shunted
Potentiometers
RONALD L. IVES
How to achieve special tapers quickly and easily
NONLINEAR
POTENTIOMETERS
are
widely used in electronic control
and instrumentation circuits, particularly in volume and tone control applications. To meet these needs, a few
of the better manufacturers have
brought out limited lines of nonlinear
potentiometers. These, in general, perform as advertised, and are suitable for
many applications.
In experimental and developmental
work the need frequently arises for a
nonlinear potentiometer with characteristics unlike any available manufactured
nonlinear pot. Special pots, it is true,
can be made to order, but their cost is
usually inordinately high, and the delivery tends to be maddeningly slow. In
most work, when a pot is needed, it is
needed today, or at least this week, and
a 120 -day delivery delay is both intolerable and uneconomical.
For quite a few decades, it has been
vaguely known in the electronics profession that connecting a shunt resistor
from the movable arm of a potentiometer to one side will change its characteristics. A few specific applications of this
principle have appeared from time to
time, but no general cases seem to be
available in the literature. Direct computation of the characteristics of a
shunted pot is, of course, possible by use
of Kirchoff's Laws. This procedure gives
perfectly correct answers, but usually
bogs down in overeomplex notations,
and is extremely vulnerable to arithmetical errors, particularly when we are
dealing with high values of resistance.
Shunted Potentiometers
e=1.0
(I
I-0
SOURCE
e
Fig.
1.
Simple potentiometer circuit,
showing notations.
stantially compatible with the "0 to 10"
dials normally provided with potentiometers, many of which have an effective rotation of roughly 270 degrees.
With this arrangement, resistance
across the source is constant and is indicated by a. Assuming that source resistance is infinite, resistance across the sink
will be aB. With no current drawn by
the sink, voltage out (to sink) will be
voltage in multiplied by B, and this will
be true for all finite values of a. This
is a simple alternate statement of the
standard voltage-divider relationship.
FEBRUARY, 1965
+Na
aB
eliminating the common a in numerator
and denominator of the second term,
this becomes:
a(1 B) +9ONa
+N
Eq. (2)
putting this all over the same denominator makes it:
aB aOQ +Na 9Na +BNa
B
+N
and, simplifying
a(B
Eq. (3)
:-
B= +N)
Eq. (4)
8 +N
Resistance across the sink is:
O
1.0
Na
a()
Eq. (5)
aB +Na
eliminating the common a in numerator
and denominator, this becomes:
SOURCE
I-0
ONa
B
Eq. (6)
+N
Now, dividing resistance across sink, Eq.
(6), by resistance across source, Eq. (4),
we get:
SINK
6=0.0
(A)
To eliminate the numerous R's with
AUDIO
SINK
0=0.0
Simplified Notation
subscripts that are employed in the
classical use of Kirchoff's Laws, as well
as the error-susceptible multiplications
of resistance values, we can use a relativistic notation, in place of the classical
absolute notation. This is shown, as applied to a simple linear potentiometer,
in Fig. 1. Here, the value of the entire
potentiometer is indicated by a; and the
degree of rotation of the potentiometer
arm is designated by B, which is a decimal as here used, with 0.0 representing
"all the way out" and 1.0 representing
"all the way in." This notation is eub-
-e)
By connecting a fixed resistor from
the moving arm of the pot to one side,
its characteristic is altered. There are
two cases of this connection, shown in
Fig. 2 as (A) and (B). In both cases,
the shunt resistor is designated relative
to the resistance of the potentiometer as
Na, N being any finite factor. Note that
in both cases, the resistance across the
load varies with the potentiometer adjustment.
In the first case, (A), resistance
across the source is
a(l B)+ a6 Na
Eq. (1)
ONa
+N
+N)
B +N
B
Eq. (7)
a(B -05
SOURCE
1111
Na
this readily simplifies to :
ON
1-0
B
SINK
e=0.0
Eq. (8)
B° +N
and, applying standard voltage- divider
concepts, it being assumed that the sink
draws no current
(B)
Eoue
Fig. 2. Potentiometers shunted by fixed
resistors.
Kin(l
N
B
B6E +
N)
Eq. (9)
which is the working formula for (A),
Fig. 2. Note that this formula applies,
19
;!'E
,E/
o
9
.
F\G
8
APPA
`'
Again, dividing resistance across sink
Eq. (12) by resistance across source, Eq.
(11), we get:
i
;/'1
E'/
_,
a0
a(0 -02 +N)
1
which simplifies to
W8
AU VA
a
Eq. (11)
O -O +N
and, again applying standard voltage divider concepts, it being assumed that
the sink draws no current:
/M.,
,P-S
E051= Etin
MIIIMEELW0'
l
IMPENEP'"LP
.5
4
.6
.8
.7
.9
I
0
VALUES OF 9
Fig. 3. Characteristics of shunted potentiometers for configurations (A) and (B) of
Fig. 2.
within the stated limitations, for all
finite values of a and N.
Derivation of the formula for (B) of
Fig. 2 is similar. Resistance across the
source is :
a(1- 0) Na + a0
a(1-0)+Na
using the same simplifications as in the
previous case, this becomes :
a(0 -O2 +N)
Eq. (11)
1 -O +N
Resistance across sink, by inspection,
Fig. 2 (B), is:
a0
Eq. (12)
Eq. (10)
0.5. Substituting:
1.0
I
Ei°
.8
-
ACTUAL POT
WITHOUT SHUNT
0
e
out
/
e =0
.7
//
/
5
.5
/
.4
/
/
/
/
/
/
//
ILS/
PERFECT
LINEARITY
.3
/
.2
MEASURED VALUES
WITH SHUNT
/
o
.2
.3
.4
.5
.6
.9
1.0
VALUES OF O
Fig. 4. Computed and measured values for
20
1
=N
Special Cases
COMPUTED VALUES
WITH SHUNT
o
Eq. (16)
Eq. (17)
Eq. (18)
Computed and measured values, using
a 1 -meg pot (Ohmite CU 1052) and a
fixed shunt of 62,500 ohms, are shown
in Fig. 4. Characteristics of the potentiometer alone, a stock item picked at
random from the shelf, are shown in this
figure also. As a general rule, with most
stock potentiometers, the values below
0=1 and above 0= .9, will be of little
use, because of "end effects." If, by mischance, the wrong equation is picked,
(say Eq. (15) in place of Eq. (9) here),
the determined value of N will be negative, immediately pinpointing the error.
.0625
62.5k
.6
u.1
/
I
.5N
- .5 -.25
+N
simplifying:
.25 =4N
1.0
0
Eq. (1u)
mula applies, within the stated limitations, for all finite values of a and N.
Characteristics of shunted potentiometers, for various value of N, for both
cases, are plotted in Fig. 3. These curves
will give an immediate indication of the
configuration required for a given circuit situation, and an approximate value
of N for most instances. Exact value of
N is determined by substitution in the
applicable formula.
This is best shown by a practical example. In a given circuit, it is required
that the ratio EoutlEti be 10 percent at
50 percent rotation of the control. Reference to Fig. 3. shows immediately that
configuration (A) of Fig. 2 is applicable, and that the value of N will be
somewhat smaller than 0.1.
Here, Eq. (9) applies, and 0 will be
0.1
.9
f0(1 -0 +N)\
+N J
B -
which is the working formula for case
(B) of Fig. 2. Note again that this for-
'mu.--.
. 2
:
0(1- 0 + N)
110111rAMEEFI
E.,
Eq. (13)
-O +N
meg pot with shunt of 62,500 ohms.
Although the two most common cases
of shunted potentiometers have been detailed, with formulae and an illustrative
example, a large number of additional
cases will occur to almost any fertile
mind. Most of these are not very useful,
and many of them are so complex as to
strain the analytical procedures outlined
in Pender and Warren'. or Guillemin.2
AUDIO
FEBRUARY, 1965
Some of these rather involved computations can be markedly simplified by use
of the relativistic notation employed in
this paper (it aetnally predates Euclid).
e =1.0
9
Tandem Potentiometers
8 =1.0
If the
fixed shunt in any previously mentioned case is replaced by another
potentiometer, and the movable arms are
ganged (in phase), a whole new family
of nonlinear potentiometers is made
available. Circuit and characteristics of
a typical example are shown in Fig. 5,
the two potentiometers here being of
equal value. For purposes of comparison, the curve of a linear potentiometer,
g
i
o
Ein
B
The similarity of this to Eq. (9)
should be obvious, as also should be the
derivation. By similar methods, a working formula for configuration (B) of
Fig. 2 can be derived, provided the moving arms of the potentiometers are
ganged in phase. Where more than two
potentiometers are operated in tandem;
when their moving arms are not exactly
in phase; or when current is drawn at
the output; then the computations become most involved, and are best handled with the techniques outlined for
"ladder circuits" in any standard work
on circuit theory.
Double- Shunted Potentiometers
What would happen if both the upper
and lower sections of a potentiometer
were shunted When a potentiometer has
a shunt from both the low side and the
high side to the moving arm, a most interesting characteristic curve is obtained,
vaguely resembling the curves of configurations (A) and (B) of Fig. 2, already discussed, placed end to end.
Formula for this connection, derived
by direct application of Kirchoff's Laws,
POT WITH FIXED SHUNT,
(A) OF FIG. 2, N= I
5
A,Pla
4
LINEAR POT
V411111
2
''
1
0
.2
.1
.3
.4
.6
.5
already mentioned. For most volume control work, configuration (A) of Fig. 2,
with N evaluated at 0.1 or less, will provide the desired volume range, although
a pair of equal ganged potentiometers
also offers interesting possibilities.
Where a potentiometer with varying
"sensitivity" is required, the doubleshunted potentiometer is useful, as it
IN
.7
.8
.9
L.
has a considerable range, yet is "sensitive" in the central portion of the range.
This arrangement works well on the centering controls of oscilloscopes and pan -
adaptors.
Other applications, as well as additional permutations and combinations,
will suggest themselves to the reader,
(Continued on page 56)
1.0
an
.9
.8
Ein
M
a
,
ll
_.,
LINEAR POT
-0
(/
1
Eout
N
7
4
=0
6
Characteristic of this potentiometer,
for the values M = N =1, is shown, along
with the circuit, in Fig. 6. By changing
the relative values of the main potentiometer a, M, and N, the position of the
point of inflection of the curve, and the
deviation of the curve from linearity,
can be changed through a wide range of
TWO ETANDEM
Q UAL POTS
Fig. 5. Behavior of two potentiometers in tandem.
EouttEin =
Eq. (20)
r
VALUES OF 8
is
NB(1- B + M)
M(1- 0)(N +0) +(1- 6 +M)(N0)
4114
VI
M,
NM.
0
6
Eq (19)
-02+ N'
I
E.,
4=0
.7
:
B
i
7
e
and of a shunted potentiometer (with
N=1) are shown on the same figure.
Formula for two potentiometers in
tandem, connected as in Fig. 5, is
EoutlEin = B
I
1.0
.8
5
ó
u,
DOUBLE -SHUNTED
POT M =N =.1
.4
.3
.2
1
values.
Applications
0
Nonlinear potentiometers are commonly used in volume and tone control circuits, as well as in the timer circuits
AUDIO
0
.1
.2
.4
.3
.5
.6
.7
.8
.9
I.0
VALUES OF f.
Fig. 6. Characteristic of
a
FEBRUARY, 1965
double- shunted potentiometer.
21
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AmericanRadioHistory.Com
Effects of Power Line Variation on LowFrequency Operation of Amplifiers
GEORGE LEHSTEN
Normal voltage variation of the a.c. power line may cause loss of 25-50%
of low- frequency power if the amplifier power supply is not properly regulated.
AMOUNT OF INTEREST has
been raised concerning the operation
of audio amplifiers during supply voltage variations. Extensive evaluation of
amplifier performance was undertaken to
select amplifiers suitable for geophysical
uses. The qualifications required in geophysical applications are perhaps more
severe than normal audio operations
since the effects are recorded on paper
or film and an absolute comparison made
for each operation.
General geophysical use of amplifying
equipment such as preamplifiers, post or
intermediate amplifiers, and power amplifiers require bandwidths and noise
figures much the same as audio applications. It was decided that a better grade
hi -fi amplifier should suffice for a large
percentage of the needed amplifying
gear. In actual use, however, hi -fi equipACERTAIN
form distortions prevail during the
period of line voltage changes. In all
the units tested, some of which were in
the $300 price range, none had sufficient power supply regulation to assume
adequate operation during these periods.
Thus in the frequency range from 100
cps down, even "good" amplifiers lost
1/2 to 1/4 of their power output capability; an amplifier rated at 50 watts
rms could deliver only about 25 watts
when the line dropped to 107 volts.
This was a rather startling fact when
one figures that the a.c. line is not con-
stant except possibly in the testing
laboratory. Some people say that the
variation occurs so quickly, say 50 -100
milliseconds that one doesn't notice it.
Our findings tend to disprove that contention. In the home, the a.c. line is
subject to loads presented by high current consuming devices such as oil
burners, refrigerators, electric irons,
ment was not satisfactory. Various tests
and actual operating conditions provided proof that this type of equipment washers and dryers, and such. These ondid not possess the needed stability and off loads present a line-voltage condiresponse.
tion where a range of variation of 15
Normal stratographic recording tech- volts or more is not uncommon, rather
niques require a general bandwidth of it is the rule. A spot check of the voltage
40 to 5000 cps. Conventional sparker ranges at the homes of several people
systems are in the higher end of the revealed ranges of 105 to 128 volts. The
frequency range, usually 300 cps to 2000 duration of these variations was up to
cps. Gas gun, boomers, and so on re- 3 seconds during the period we checked.
quire the lower end of the spectrum, 40 We understand that during the air condito 300 cps. Upon looking at these fre- tioning season the drop lasts much
quency ranges it would seem that con- longer. It would seem rather obvious
ventional hi -fi gear should cover the from this that a non-regulated supply
needed range since most units advertise would not have a chance to properly
a range of 20 cps to 20,000 cps. While furnish power to electronic equipment
they do cover these ranges, other specifi- that requires a specific supply level to
cations needed, such as stability and maintain a preconceived degree of perlinearity, deteriorate rapidly especially formance.
at the lower end of the response spec- Trying to Solve the Problem
trum.
Keeping these results in mind, active
The most pronounced defect at the work was started to develop amplifier
low end of the frequency range was sus- equipment which would perform well
ceptibility to the effects of line changes. with the type of line variation normally
In order to evaluate the nature of these encountered. Two types were involved.
effects the units were coupled directly The first type encompassed voltage into recording instruments that were ca- sensitive circuits for applications where
pable of recording frequencies up to the available power supply and size were
several hundred cycles. Thus it was pos- of paramount importance and the limitsible to see the effects as they occurred ing factor, such as in portable gear. The
and have a permanent record of the dis- second type included precision regulated
torted signal for comparison. These supplies used in conjunction with inrecords show that even if the amplifier sensitive circuits when their use did not
were driven to only a part of its total deteriorate the over -all performance of
rated output power level, serious wave- the system or component. This philosophy was carried out to the extent of pro* Chief Engineer, Electronics, Alpine
gramming the supply to provide the
Geophysical Assoc., Inc., Norwood, N.J.
necessary regulation at the tube or transistor element, not only at the common
supply point. This approach made the
power supply rather complex, however
performance was the important consideration.
The initial design used a regulated
supply for the entire unit. The output
amplifier, its driving amplifier, and the
phase inversion stages were to be directly under the control of a regulated
supply. The plates of the output tubes
had a "negative impedance" characteristic to the degree that compensation for
the voltage drop in the output transformer plate winding did not appear at
the plates of the tube. The amount of
correction was based on the d.e. resistance of the winding at the operating
current.
The input amplifier was not under
direct regulation but was allowed to
remain in a normal resistive decoupled
configuration. Since this amplifier was
a modified cathode follower, it was insensitive to plate supply voltage variation. The remaining voltage gain stages
and driver for the phase inverter were
supplied from the output screen supply
which was also closely regulated. The
reasoning behind this being that the
effect of the output screens is the inverse
of the voltage amplifier section provided that the plates and bias are not
allowed to change. Fixed bias from a
precision supply completed the general
design.
The power supply itself consisted of
a series regulator pass tube for all potentials except the bias which used a
shunt regulator system.
Having completed this aspect of the
problem the next step was to correct, as
far as practicable, the deficiencies of
existing equipment. This problem was a
bit more complex as the original design
of this equipment made no provision
for the effects of supply regulation. Several "dual" amplifiers were subject to
these modifications with a vast improvement in performance. However, in certain aspects these units are not improved
enough to justify the added cost of a
regulated supply.
Several different conditions are apparent as a result of supply voltage variation. Each occurs during the voltage
change, and some remain as a result of
(Continued on page 61)
AUDIO
22
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AmericanRadioHistory.Com
FEBRUARY, 1965
Temporary Sound Amplification
Systems
DAVID
L. KLEPPER
Temporary systems can be well engineered, even though the time
allowed for design and installation is limited. (For clarity Part One
should follow Part Two -the author intended it that way)
IN TWO PARTS -PART TWO
Billy Graham Greater Boston Crusade in September and October 1964
presented an opportunity to demonstrate that even temporary sound amplification systems can be engineered on
the basis of known acoustic principles to
provide high -quality results. Two systems
were involved; an indoor system for the
Boston Garden, intended for eight days
of use and later employed for a "return
engagement" of one week, and an outdoor system designed and installed on a
last- minute basis for an afternoon gathering on the Boston Common. Important
considerations in the design of both systems included: 1. Adequate coverage of
the audience area with minimum feedback; 2. directional realism for the maximum number of listeners; and 3. avoidance of artificial echoes. All amplified
sound energy was to arrive at the listener's ear at approximately the same
time.
The
The Boston Garden System
The Boston Garden's permanent loudspeaker system, installed over thirty
years ago, is useful for many regularly
scheduled athletic events, but less than
adequate for other special uses as cultural or religious activities. Previous experience indicated that fine sound could
be obtained in the Garden, if a properly
engineered sound system was installed.'
The functional requirements for the
Garden temporary system were :
1. Reinforcement of speech from the
podium, with coverage for the entire audience area.
2. Reinforcement of both piano and
Hammond electronic organ from
the platform with coverage for the
entire audience area.
*
Bolt Beranek and Newman Inc., Cambridge, Massachusetts
4 Beranek, Radford, Kessler and Wiesner,
"Speech Reinforcement System Evaluation," Proceedings of the IRE, vol. 39, No.
11, November 1951, pp. 1401 -1408.
AUDIO
FEBRUARY, 1965
Reinforcement of speech from the
choir director's lectern with coverage for the choir area only.
The advantages of "central" loudspeaker systems with loudspeakers clustered over the source of live sound, in
spaces where they are applicable, have
been discussed previously."' T When
properly designed, such systems can
provide high intelligibility and naturalness by assuring that live and amplified
sound arrive at the listener's ears at approximately the same time, and from
approximately the same direction.
All seats could not be covered from a
central loudspeaker cluster; line -ofsight was blocked by balcony overhangs
over the lower side and rear seating
areas. Also, the area behind the platform was occupied by a large voice
choir, and a separate system was necessary, enabling the choir director to
speak to the choir without his voice being amplified in other seating areas. The
complete system, therefore, was a compromise, using distributed loudspeakers
to supplement the coverage of the central loudspeaker systems. The line diagram of the system is shown in Fig. 6.
Location of speakers is shown in Fig. 7
3.
Central Cluster
The central loudspeaker cluster design
illustrated in Fig. 8. Phasing considerations for smooth frequency response
required close spacing of the high-frequency drivers. This results in equal
path -length for amplified sound energy
received by listeners in overlap areas
covered by two horns.
The low- frequency loudspeakers were
designed to be in a vertical line above
the high-frequency drivers for best
is
Ibid.
H. F. Olson, Acoustical Engineering,
D. Van Nostrand Co., Inc., Princeton, N. J.,
5
6
1957, p. 518.
r D. L. Klepper, "Central Vs. Distributed
Systems," AUDIO, vol. 48, No. 6, June 1964,
p. 19.
phasing at the crossover frequency for
most seating areas covered. A last -minute installation compromise resulted in
a different arrangement of low-frequency
loudspeakers, with two single -loudspeaker low- frequency horns side -byside. The phasing problems in the crossover frequency range and lack of
directional control introduced by this
compromise were evident when the central loudspeaker system was equalized,
as will be discussed later.
The lowest horn of the cluster was
used only when people came forward to
an area immediately in front of the platform at the end of the service. At other
times, this area was unoccupied, and
the horn was switched off.
Different transformer taps were used
for high- frequency horns, as illustrated
in Fig. 6. to partially compensate for
varying distances to areas covered by the
central loudspeaker cluster.
The orientations for the high -frequency horns were obtained using the
techniques described by Malmlund and
Wetherill8 (a three dimensional scale
model of the seating area, a light machine with templets for horn coverage in
the 2400 -4800 cps range). This design
technique proved to be especially useful for the very complex coverage problem posed by the Garden seating layout.
A 160 -watt amplifier fed the central
cluster and levels could easily meet the
95 db criteria for the system.
Distributed Systems
Eight -inch coaxial loudspeakers in
small, 1.5 cu. ft., glass -fiber filled wood
enclosures were used for the distributed
loudspeaker systems.
The first distributed loudspeaker zone
included the choir seating area and upper balcony behind the speaker's stand.
s Wilfred Malmlund and Ewart Wetherill, "Design of Complex Directional Loudspeaker Clusters," presented at Audio Engineering Society Convention, New York,
October 1964. Preprints are available from
Audio Engineering Society.
23
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Fig. 6. Line diagram for the Boston Garden system.
24
AUDIO
FEBRUARY, 1965
B
C
C
C
C
c
A
A
C
A
C
A
C
C
B
ARENA FLOOR PLAN
,/
A
\
HF HORN #6
HF HORN 05
RCA
ALTEC LANSING
A
A.
A
o/
A.
LOUDSPEAKER CLUSTER
A
A.
A
HF
HORN #4
HF HORN 15
ALTEC LANSING
RCA
8" OVERHEAD LOUDSPEAKERS, 16' ABOVE FLOOR LEVEL, MOUNTED PARALLEL TO FLOOR SLOPE
Fig. 7. Loudspeaker locations for Boston Garden
1
Here the loudspeakers were suspended
by separate wire cable, and each enclosure angled so that the loudspeaker
centerline was perpendicular to the seating slope. The enclosures were located
roughly ten feet above seated head
height. All loudspeakers were tapped for
8 -watts from a 70 -volt line, fed by one
160 -watt power amplifier.9
This amplifier was, in turn, fed by an
independent mixer, allowing the choir
AUDIO
director's microphone, and the microphone for the piano to be heard by the
choir, without being directed to the audience. A third choir mixer input was fed
from the main mixer output.
The choir loudspeakers were judged
sufficiently close to the central cluster
9 For a discussion of the constant voltage
basis for sound distribution, see N. Crow hurst, "A Basic Course in Commercial
Sound -Chapter 4," AUDIO, vol. 48, No. 7,
July 1964, p. 30 -31.
FEBRUARY, 1965
system.
not to require time delay. (Realism
would certainly have been helped by time
delay, but the added complication and
cost did not appear justified for a temporary system.)
Time delay was considered essential
for the signal to the other two distributed
loudspeaker zones, however.
Two delays were used. One, approximately 70 milliseconds, was used for the
side under -balcony loudspeakers and the
25
www.americanradiohistory.com
AmericanRadioHistory.Com
other, approximately 140 milliseconds,
was employed for the rear under-balcony
loudspeakers.
Two more 160 -watt amplifiers were
employed, one for the side loudspeakers
and one for those at the rear; again
these loudspeakers were connected to
draw 8 watts from the 70 -volt line.
The side and rear wood loudspeaker
enclosures were all suspended from the
balcony soffits above. The side under balcony loudspeakers were centered over
the sloped seating area requiring coverage, and their axes were perpendicular
to the seating slope. However, the rear
under -balcony loudspeakers were actually located over the overlap zone
between the central and distributed loudspeaker system; consequently, they were
directed toward the rear of the under balcony coverage area.
Microphones
Billy Graham has worn an omnidirectional condenser microphone as a wired
lavalier microphone for talks during the
past fifteen years. This microphone has
an interesting history ; it was built in
1949 (from the early Altee M -11 microphone system) and uses the 21B microphone "button" but in a special brushed
aluminum "lipstick" case. The microphone system was the development or
pilot model of the now -familiar M -20
"lipstick" microphones, and was supplied to Billy Graham by John Hilliard,
then chief engineer of Altec Lansing.
The signal from this microphone is fed
directly to the ABC network input
equipment and a padded output was fed
from the ABC mixer to the main sound
reinforcement system mixer.
A dynamic cardioid microphone was
used at the podium for all speakers
except for Billy Graham. The signal
from this microphone was also fed to
the main sound reinforcement mixer. A
second cardioid microphone was used
for the choir director, feeding only the
choir system mixer. Omnidirectional
microphones were used for organ and
piano pickup; the organ microphone was
fed directly to the main mixer and the
piano microphone to both the main and
choir mixers. Finally, a bridged padded
output from the main mixer was connected to the number 1 input of the choir
mixer, allowing the choir to hear all
One may speculate that the first three
feedback modes appeared at this frequency because of the compromise to
the low- frequency portion of the loudspeaker cluster and the resulting lack
of phase alignment of the low -frequency
loudspeakers and high -frequency drivers.
This compromise may have destroyed
any directional control of the loudspeaker system in the crossover range
and may have resulted in peaked response behind the loudspeaker. No measurements were performed to further
check this hypothesis. Once the three
modes in the crossover region were suppressed with narrow-band equalization,
the central loudspeaker system had
great reserve gain over feedback, over
15 db above the gain required for system operation.
Since the necessary time for carrying
out many stages of narrow-band equalization was not available, a frequency
shifter feedback stabilizer was specified
to insure a satisfactory margin of gain
quency response of the central cluster
system with 1/3- octave band filtered
noise tapes applied to the console input. Measurements were performed with
a Bruel and Kjaer sound level meter to
measure the response at four different
typical seat locations. This broadband
equalization, together with use of all 4
db of high-frequency padding available
on the crossover network, yielded a
slightly downward sloping smooth frequency response.
We had planned on using narrow-band
equalization to provide great reserve
gain before feedback for the complete
sound system.1° Unfortunately time was
too short to exploit this technique fully,
and only three narrow -band LC sections
were employed to control feedback
modes around the crossover frequency.
10 C. P. Bonner, "A Procedure for Minimizing Acoustic Feedback and Room Modes
in Sound Systems," presented at the Audio
Engineering Convention, New York, October 1964. Preprints are available from
Audio Engineering Society.
(Continued on page 57)
AIMED 7° UP FROM HORIZONTAL LINE
TILTED 10' UP FROM HORIZONTAL AXIS
LF
ENCLOSURE
1210
3/4" PLYWOOD
WING
9°
HF
ION
I ,
HORN
11 803B
9°
10
°F
HF
HORN 14 10038
HF
-41
%%1 \\,
HORN 12 1003B
HF
HORN 13 1003B
REP
04
11.14
HF N5
HORN 1003A
42°
1
FRONT ELEVATION
75°
SIDE ELEVATION
LF
ENCLOSURE
60°
speeches.
Equalization and Feedback Suppression
Broadband equalization was applied
to the amplification channel feeding the
central loudspeaker cluster and consisted of an RLC network giving approximately 4-db loss to an octave centered at 1.8 ke and high -frequency boost
raising the response by 8 db at 10,000
cps. This network was installed following measurements of the over -all fre-
6
HF
HORN /4
PLAN (LOOKING DOWN)
Fig. 8. Central loudspeaker cluster.
AUDIO
26
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
the revolutionary
34"
:OMNIDYNE
PROBETMODEL
DIAMETER
578
1.M.
GIVES you more features you want from
an omnidirectional hand -held microphone
MODEL
578
ACTUAL
SIZE
HAN DABILITY-Smallest, sleekest, most compact quality omnidirectional
dynamic probe! 400 /o smaller diameter, 600 /o smaller area. Lockable on -off
switch right on the microphone case! Balanced "heft" -feels great in the hand.
Easily removed and returned to stand. Swivel adapter included.
UNIFORM COVERAGE -Virtually no change in pick -up pattern or sensitivity from 50 to 17,000 cps. Easiest microphone to use because there are no
"critical" areas in the pick -up pattern .. no "hot" spots, no areas of reduced
sensitivity.
SIMPLICITY -Rugged, all -steel case resists abuse. No separate microphone
connectors to hook -up (or accidentally fall off).
SOLVES the most common problems of other
omnidirectional microphones
FEEDBACK -Proved much less susceptible to feedback because its unique
ultra -flat response has no undesirable peaks at any specific frequencies (a
major cause of omnidirectional feedback).
DISTORTED SOUND -The most natural sounding omnidirectional microphone ever developed. No "off- axis" sound coloration. Smaller diameter
means there's far less of a "blind spot" in the pick -up pattern. No troublesome
"boominess ", no fall -off at the high end.
EQUALIZATION -By far the easiest omnidirectional to equalize to the
because it's
characteristics of the speaker's voice and the room acoustics
ultra -flat
adds no false peaks or roll -offs of its own.
...
...
HUM PICK -UP -Steel
case reduces hum of the 578 to half that
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PERFORMS PERFECTLY in scores of diverse applications
-In
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VERSATILE
their superiority in an impressive array of applications ranging from stage and
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called for.
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SPECIFICATIONS -Dynamic omnidirectional with ultra -flat frequency response
and perfectly symmetrical pick -up pattern. 50 to 17,000 cps. Dual impedance:
High impedance has 59 db output (0 db = 1 volt per microbar), 200 ohm (low)
impedance has 60 db output (0 db = 1 milliwatt per 10 microbars). Trouble -free
Duracoustic diaphragm. Steel, satin -chrome case. Built -in on -off switch with locking provisions. Supplied with swivel stand adaptor and 18 ft. 3 -cond. shielded
cable. Only 7 oz. (less cable), 3/. in. diam., 73/s in. overall length.
WRITE FOR TECHNICAL DATA SHEET AND CATALOG:
SHURE BROTHERS, INC.
222 Hartrey Ave.
Evanston, Illinois
WORLD STANDARD WHEREVER SOUND QUALITY IS PARAMOUNT
Circle
AUDIO
FEBRUARY, 1965
151 on Reader Service Card
27
This is
the Actual
Size:
Fs by
NO
en
FEET
!INCH
,
'61965 UTC SOUND DIVISION, Gar,
www.americanradiohistory.com
AmericanRadioHistory.Com
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Now, you need not compromise on space or your listening pleasure.
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enclosure, especially appealing to the ladies, but designed as well for space- starved audiophiles. The
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www.americanradiohistory.com
AmericanRadioHistory.Com
Special Electronic Organ
Tone Sources
D.
WOLKOV
The Band -Box, Side -Man and ChimeAtron represent three different methods for the production of sounds complementary to the electronic organ
THE OLD THEATRICAL AIR ORGAN,
and
some of the classical air organs, employed as adjuncts such percussive
instruments as drums, triangles, caste nets, and so forth. These were operated
through air controllers, with the musician
operating the pilot valve (or electrical
value actuator) at his keyboard.
The electronic organ industry has provided the home musician with scaled
down versions of similar percussion sections. Of the units available, three are
particularly interesting. All three of
these "traps" operate on different principles a. The Artisan Band-Box is a
group of genuine percussive musical instruments that are solenoid actuated; b.
The Wurlitzer Side -Man is a specialized
electronic organ with a motor driven
switchboard in place of the conventional
keyboard. c. The Schulmerich Chime Atron, an electronically amplified set of
musical chime bars.
The Artisan Band-Box would on the
first consideration seem to be useful only
for the playing of hurdy -gurdy music.
But consider the amount of traps that
different conductors have used in recent
recordings of Ottorino Respighi's works,
or more obviously in the Strauss waltzes.
The Band -Box includes a large fraction of the number of percussive instruments that one would find in the
percussion section of a modern symphony
orchestra. The instruments in the Band Box are genuine musical instruments operated through solenoid mechanisms. If
remote sound is required then microphones and the usual amplification techniques must be used.
The Wurlitzer Side -Man, in contrast,
does not contain a single musical instrument. All of the percussive sounds are
generated and modified by vacuum tube
oscillators and formant filters respec:
Fig. 2. Band -Box, rear view, showing actuators.
matie as the older and more familiar
player piano.
The Schulmerich Chimes are musically
tuned rods which are struck by electromagnets; an inductive pick -up changes
the mechanical vibrations of the rods to
electrical oscillations; the electronic signal is amplified and then heard as sound
at the speaker. Chimes were originally
associated with religious music. Today,
however, many organists are using chimes
in popular music with noticeable dramatic musical effects.
Artisan Band -Box
We begin our detailed discussion with
the Artisan Band -Box. Figure 1 shows
the front view and Fig. 2 the rear view,
the latter shows the instrument actuators. A typical setup includes
:
Fig. 3. Wurlitzer Side -Man.
Fig. 1. Band -Box, external view.
tively. An adjustable -speed motor-driven
switch provides the tempo settings and
a manual switch is used for selecting the
tonal combinations.
The Side -Man is obviously designed
for dance music, it is almost as auto-
Pedal
Great
Snare Drumi
Cymbal Crash Cymbal Tap
Roll
Cowbells
Cymbal Brush
Maracas
Wood Block
Castenets
Snare Drum
Beat
www.americanradiohistory.com
AmericanRadioHistory.Com
Tambourine
Sleigh Bells
Triangle.
There is nothing special about such and
arrangement, and the user can rear-
AUDIO
30
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FEBRUARY, 1965
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FEBRUARY, 1965
31
on the techniques of oscillators and fil-
Fig. 4. Front interior view of Wurlitzer
Side -Man.
range the cabling, or group the controls
into one box at his discretion. Wiring is
extremely simple.
Since all of the instruments in the
Band -Box are true musical instruments,
we will not, in these articles investigate
their scientific aspects, but instead, we
will pass on to the description of the
techniques which make them compatible
with electronic organ playing methods.
Readers who are interested in the scientific aspects of these musical instruments
will find "A Textbook of Sound" by
A. B. Wood (Macmillan 1937) most useful. This book contains detailed mathematical analyses for all of the instruments in the Band -Box.
Instead of air hoses, valves and air
actuators, which were used to operate
the trap section of an air organ installation, the Band -Box uses electrical solenoids. The complete grouping of actuators is shown in Fig. 2. A make -break
contact arrangement is used in the snare
drum actuator. These contacts provide a
very rapid drum roll of high rhythmic
uniformity.
At one time Artisan supplied the
Band -Box as a kit. In line with the
growing trend to keep mechanical assembly out of kits (Schober for example in
their new keyboards), Artisan now only
furnishes the Band -Box completely assembled.
The Artisan percussion instruments
are soft and melodious in their voicing.
They form delightful contrasting and
complementary sounds to the electronic
organ,
There are several Artisan records
available from Electronic Organ Arts,
4949 York Boulevard, Los Angeles 42,
California, These records have the Artisan Band -Box sounds incorporated in
the various musical arrangements.
Wurlitzer Side -Man
In contrast to the Band -Box, the Wurlitzer Side -Man does not contain a single
musical instrument but depends, instead,
32
ters. The percussion sounds vary in
rhythm patterns which are suitable for
all of the rhythms used in today's popular music. Maracas, temple blocks, tom
toms, and other similar sounds are combined in the patterns of the rhumba,
bolero, waltz, fox trot, and so on.
Figure 3 shows the exterior view of
the Wurlitzer Side -Man and Fig. 4 and
5 show the interior views. Figure 6
shows the control panel.
The circuit of the Side -Man is straightforward. There are ten continuously operating tone generators. The output of
these generators are fed to the preamplifier and then to the audio system
through a selector switch.
The oscillators can be grounded (i.e.
stopped) by manual pushbutton switches, or they can be cyclically grounded
by the variable speed motor (tempo
wheel) .
Figure 7 is the schematic for the tone
generators, the audio oscillators, and the
Fig. 5. Rear interior view of Side -Man.
formant filter networks. Note that each
oscillator tube is also the power tube.
The real story of the Side -Man is the
switching setup. The ten basic tone generators are tonal building blocks. Instead of having the musician pull his
own stops, the selector switch acts as a
variable piston. Thus for each position
of the switch there is a preselected group
of tones which are collected and fed to
the preamplifier.
In addition to providing the audio mix,
the selector switch provides the wiring
schedule to the rotary motor driven
switch shown in the upper right hand
side of Fig. 4.
For a given rotational speed of the
tempo wheel, there will be a tone pattern mix, previously selected and a fixed
rhythmic interruption of the tone pattern.
It is through such ingenious wiring
techniques that the ten oscillators can
provide rhythmic patterns for all of the
musical groupings shown on the control
panel. In addition, 72 variations of block
and cymbal patterns are available in the
fox -trot section.
The speed changing mechanism is the
fa niiliar disk and rim drive. (See Fig. 8.)
The position of the Tempo Lever determines the position of the rim drive and
hence its speed, i.e., the tempo.
The design of the power amplifier is
such that the internal amplifier and
speaker system can be bypassed. This
should not be done for best audio results. The organ and Side -Man sounds
should come from different sources.
With the Side-Man and an electronic
organ you can be a soloist and a rhythm
combo all by yourself. It is an interesting experience, try it for yourself.
Schulmerich ChimeAtron
The Schulmerich ChimeAtron is a
combined mechanical and electronic musical instrument. The faint musical sounds
of the electro-mechanically struck bars
are picked up through inductive coupling. The electrical signal is then amplified and converted to sound at the
speakers. The chime sound is such that
it cannot be readily simulated by oscillators and filters.
In Fig. 9 we see part of a tuned set of
the Schulmerich ChimeAtron bars, cut to
such lengths so that slightly more than
two octaves of fundamentals can be
sounded. This figure also shows the amplifier chassis.
Note that the well -engineered suspension (Fig. 10) permits the bar to act as
if it were completely free at both ends.
The bar is actually supported at the bottom by nylon threads and spring sup-
ports.
An appealing feature of the Schulmerich system is the controlled diminuendo. A fine wire V is inserted into the
end of the hammer. In the normal rest
position, the V rests against the hole in
the anvil of the rod. When the coil is
(Continued on page 60)
Fig. 6. Control panel and tempo level
bar of Side -Man.
AUDIO
FEBRUARY, 1965
What a crazy, lovely, naive,
ingenious company.
BOGEN makes a professional turntable with 59 speeds
and automatic cueing for only $69.95
The 862 is only $69.95.
That's very lovely.
If anyone else made
the 862, it would sell
for at least $99.95.
(Read on. You'll agree.)
Of course. You've got to be
to make anything as
great as the B62.
Crazy like Galileo, Fulton, Edison.
Sure. Bogen actually expects people to believe
they can own a professional turntable for under $70.00!
Of course. With 33 years of
technological leadership
Bogen can provide a professional
turntable at such a moderate price.
-
The B62 has automatic cueing. Great for
the man who's "all thumbs." No more damaged cartridges or records for B62 owners.
Instead of lowering the arm by hand, the
cueing lever does it for you. It lets the arm
down with feather lightness into any groove
you choose. It also has variable speed control; 59 speeds, from 29 to 86 r.p.m., with click stops at
78, 45, 331/3 and 16 r.p.m. For those who like to "perform"
with records, and for dancers and musicians, the B62
changes record pitch to match that of voice, instrument or
dance tempi. It lets you hear old 78's at
their original 80 r.p.m. speed. Also great for
16" transcription records with a single adjustment. There's also a massive 73/4" pound table!
Rumble is inaudible, and the professional balanced
tonearm accepts all popular4 -pin plug -in cartridges.
For more complete specifications, of the B62 and other new
Bogen components write: Bogen, Dept. C -2, Paramus, N.J.
BOGEN
COMMUNICATIONS DIVISION
r,.._..
1.Si
LEAR SIEGLER, INC.
PARAMUS, NEW JERSEY
Circle 116 on Reader Service Card
AUDIO
FEBRUARY, 1965
33
www.americanradiohistory.com
AmericanRadioHistory.Com
to respond, whereas a phono system may
be less limited in this respect. Thus distortion that measures the same on two
systems may be easier on the ear in one
case than in the other.
Tape Head Output
Q. In attempting to play directly from
a tape head into the magnetic input of
my audio amplifier, the sound level is
HERMAN BURSTEIN
(Note: To facilitate a prompt reply,
please enclose a stamped, self-addressed
envelope with your question.)
Herman Burstein
280 Twin Lane E., Wantagh, N.Y.
Solving the Stretched Edge Problem
Colonel W. D. Tiffany (5906 Accomac
Street, Springfield, Virginia) writes the
following about the problem of prerecorded tapes with a stretched edge, discussed in the November 1964 issue
"This problem has plagued me since
1961 when I was stationed in Korea and
obliged to buy my prerecorded tapes
from the Post Exchange. The relatively
long storage and shipping times resulted
in considerable dehydration of the plastic tapes used by virtually all of the
recording companies. I found that some
tapes had `stretched edges' at the time
I purchased them; other developed this
fault after having been played and then
stored after in Korea's alternately dry
:
and humid seasons and secondly in
Washington D.C.'s similar cyclic variation in humidity.
"I have concluded that my trouble
lies in habitually playing only the first
side of some tapes, and then rewinding
and putting the tape away. I believe the
stretch is due to the tendency toward a
tighter wrap near the hub of the reel
during rapid rewind, and an appreciably
looser wrap toward the outside of the
reel. This may permit more absorption
of moisture in the loosely wrapped portion. As an experiment I reversed a
stretched tape on its master reel (3 rewinds) so that what had been toward
the outside of the reel was now toward
the hub. After four days of storage I
found that from 90 to 100 per cent of
the trouble had been corrected.
"The ultimate solution lies in inducing
the tape recording companies to use
Mylar, preferably 1.5 mil. My own tapes
(that I have recorded) have never exhibited this irksome problem.
Input Level
Q. I am feeding the signal from a
ceramic cartridge directly into my * * **
tape recorder, but the signal is weak and
forces me to set the recording gain control quite high. Therefore I am not getting as good a signal -to -noise ratio as I
should be getting. Would it be better if
I took the input signal from a point in
my audio system where there is a higher
signal level, instead of directly from the
cartridge?
A. In the case of the * * * * tape machine, the high -level input goes directly
to the recording gain control and does
not first go through a preamplifier stage.
Therefore the setting of this control
should make no difference in the signalto-noise ratio, provided there is enough
signal to drive the tape machine to maximum permissible recording level as
shown by the level indicator. Possibly
you are getting an inadequate signal -tonoise ratio because of distortion in the
bias waveform when recording; such
distortion produces noise. A top quality
machine employs great care in the design of the bias oscillator and the quality
of components used in the oscillator so
as to minimize waveform distortion. To
improve the signal -to -noise ratio you
might try high output tape, which can
improve the ratio about 6 to 8 db. However, such tape tends to bring on other
problems, including greater printthrough. But these other problems may
be less offensive than the noise which
now bothers you.
Is IM an
Indicator of Quality
Q. In a modern phono system it is possible to keep IM distortion no higher
than 2 per cent. Yet reputable tape re-
corders produce IM measuring several
times as much. At the same time, tape
appears to handle the large climaxes so
much more easily than records. Hence
is IM distortion measurement realistic?
A. I am not sure that 2 per cent IM is
the most you can get on a phono system.
This may be what you get at an average
recording level, but it may rise a good
deal higher on peaks. The extent to
which distortion affects the ear depends
not only on the magnitude of distortion
but also on the frequencies of the distortion components. In the case of a tape
system, higher order distortion components may be greatly attenuated because of the inability of the tape head
virtually inaudible unless I advance the
volume control very high. My tape machine has no output jack for feeding an
external amplifier.
A. All tape heads put out an extremely
low signal, on the order of a very few
millivolts or a fraction of a millivolt,
depending on frequency. The high setting required of the gain control is
therefore understandable. By feeding
the tape head to the magnetic phono input, you are getting incorrect playback
equalization, resulting in insufficient bass
and in treble cut. This too may account
for the amount of gain that has to be
supplied. Try taking the tape playback
signal from across the volume control
of your tape machine, and feed this signal into a high -level input of your audio
amplifier.
Head Wear and Pressure Pads
Q. Recently I purchased a * * ** tape
recorder. The only item that I am not too
pleased with is the tape tensioning device, which consists of a foam backed
plush pad that comes into contact with
the three heads during record and play.
My question is this: Does this type of
pressure pad increase wear on the heads
as compared to other systems in the same
price class ($400 to $500). Perhaps you
can suggest ways to minimize excessive
head wear.
A. It is generally considered that
pressure pads cause faster head wear
than a system of tape guides and tape
tension (exerted by the reels) to provide
close tape -to-head contact. However, it
is easier and less expensive to achieve
good contact through pads than by other
means. Hence only the top bracket machines avoid pads altogether. Some of
the better machines limit the use of a
pad to the erase head or to a tape guide.
To minimize the consequences of using
pressure pads, I suggest that you use
top quality tape, which will contain
suitable lubrication to facilitate passage
of the tape across the head. You might
also employ one of the special fluids sold
in audio stores for lubricating tape
heads.
European Equivalents
Q. What are the European equivalents
of 7.5 ips speed and 1/4 -in. tape?
A. 19 cmps (centimeters per second)
speed, and 6 mm tape.
(Continued on page 67)
AUDIO
34
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
Some plain talk from Kodak about tape:
Bias transfer characteristics
and dependent parameters
Ever heard the story about the pilot
on his first solo flight? Unfortunately
the engine failed. But fortunately he
had a parachute. But unfortunately
the chute failed to open. But fortunately he landed on a haystack. But
unfortunately there was a pitchfork
in the haystack. Except for the unhappy ending, this might be the story
of how gamma ferric oxides respond
to magnetic fields. Everything about
it is fortunate with one exception.
Linearity. The oxide needles used in
the coatings have atrocious linearity
characteristics. Feed in a clean, pure
sine wave and out comes a non sinusoidal complex waveform that
looks something like a demented snake
trying to bite its own head off. How
does it sound? About as pleasant as
Junior's first violin lesson.
How then is magnetic recording
possible? Fret not- there's a way out.
The entire problem is solved by one
wonderful, mysterious phenomenon
called bias. The transfer curves tell
the story.
OXIDE
CHARACTERISTICS
CURVE
does is because the sine wave input is
affected by the non -linear characteristics of the gamma ferric oxides. But
look closely. Note that while the oxide
performance is non -linear when taken
over its entire length, we can find
linearity over selected sections. In
other words, we can get rid of our distortion if we can put the signal on the
linear section of the oxide's characteristic curve. And that is exactly what
bias does. It "lifts" the signal away
from the convoluted central area on
the graph and moves it out to linear
areas.
.
NON -LINEAR
- .-
OXIDE
CHARACTERISTIC
CURVE
N.E. AC BIAB -P
alk
auOUTPUT
407617sTAT
''
V.V..
Se4
= =,
AUDIO OUTPUT
AUDIO INPUT
providing you have a bias setting of
about 4 milliamperes. (Curves for the
other magnetic parameters are similar in shape and all peak at about the
same bias level.) Vary one milliampere and you "fall off the curve" and
suffer severe losses in sensitivity. Now
look at the broader curve. You can
vary a milliampere with hardly any
change in performance at all. Here's
the point. Kodak tape has that broad
curve. It gives you top performance
even though your bias settings aren't
perfect. And if your tape recorder is
more than a year old, then chances
are enough shift has taken place to
push you off the cliff. That's why we
designed a broad bias curve. And
that's why you need it. It's just one
more way that Kodak tape gives
you an extra bit of assurance of top
performance.
The amount of bias (that is the current in milliamperes) applied to
the head is highly critical if top performance is to be achieved. Bias affects
output, high and low frequency sensitivity, signal -to -noise ratio and distortion. This curve explains it.
SOUND RECORDING TAPE
AUDIO OUTPUT
~AUDIO INPUT
The slightly twisting curve at the
upper left represents the oxide response. The lower curve is a pure,
sine wave input. At the upper right
we have the result of the response
a mess.
curve on the input
The reason it looks the way it
...
The steep curve represents low frequency sensitivity (measured in db.)
at varying bias levels for many tapes.
Note that you get good performance
KODAK Sound Recording Tapes
are available at all normal tape outlets: electronic supply stores, specialty
shops, department stores, camera
stores ... everywhere.
©Eastman Kodak Company, MCM LXI
EASTMAN KODAK COMPANY, Rochester, N. Y.
Circle 117 on Reader Service Card
AUDIO
FEBRUARY, 1965
35
A New Look at FM
HARRY
After many
destined for
36
MAYNARD
years of "genteel poverty," FM broadcasting seems
a greater measure of success in the next decade.
FM radio received
what most observers of radio regard
as a major shot in the arm. The
Federal Communications Commission
proposed that every AM -FM radio station in America in cities of over 100,000
population, program at least 50 per cent
original material on its FM outlet by
August 13, 1965.
Up to now, if you listened to a major
AM -FM station, you usually heard the
same programming on FM as you did on
AM. With this new ruling you may have
at your fingertips the equivalent of half
a new station.
To some observers in the communications industry, this new ruling is dynamite. The most important question it
raises among those concerned (and this
includes the listener as well as the program director and the station owner) is
what sort of investment are the major
radio interests such as NBC, CBS, ABC
and major independents going to make in
separate radio programming-aptly described as "Radio for Grownups" by Nat
Hentoff in The Reporter (May 1, 1958).
Some people in the broadcasting industry fear that the FCC rule limiting
FM duplication of AM broadcasting is
only the first step in a move to separate
AM from FM, and eventually to separate TV station ownership from either
or both (when all three are owned by
the same group). The Commission did
not, in the adopted ruling, deal with the
problem of (AM -FM) dual ownership
in the same community, although it did
express the view that separate ownership of local AM -FM stations is a desirable long -range goal.
Apparently, the FCC regards necessity
as the mother of investment. So far, the
independent FM station has led the way
in demonstrating that it can offer more
variety and quality than has often been
available on AM. The FCC also hopes
that FM with community- oriented radio
stations will lead the way in meeting
the need for night time coverage in places
where there have been gaps in radio
coverage, especially in smaller cities and
towns.
Perhaps there is a parallel in the
FCC's recent ruling requiring that all
TV sets now manufactured be equipped
to receive ultra high frequencies (UHF).
AFEW MONTHS AGO
E.
revenue passes that of AM radio, whose
predicted trend line should start downward in 1970.
The Harvard crystal-balling is based
on FCC broadcasting revenue information. Their basic premise is that combined AM -FM radio will remain at the
present growth rate of 33 per cent. This
growth rate has prevailed over a five year period (1956 -1961) and rose to
36 per cent over the 1958 -1961 period.
Are Harvard's projections realistic
AM -FM owners, according to Broadcasting Magazine, were "inclined to wonder
if the Harvard study might be on the
and the advertising
optimistic side
world took a let's- wait -and -see attitude."
The Harvard Study
Is the Harvard study confirmed by
Last year, Harvard Business School other evidenced Yes. Perhaps the biggest
did a massive study of FM, which pre- confirmation is indicated by the present
dicted a happy future for it. The sub- sales of FM versus AM receivers.
stance of the report was that FM radio
FM receiver sales have exceeded most
would catch up with AM radio, in all industry projections, from two million
revenues, and pass it in the early 70's. sets a year in 1960 to a total of 6,400,000
The Harvard projection indicated that units by the end of 1964. By 1967, there
both AM and FM racked up 5.83 per is every indication that sales of FM and
cent of the national advertising dollar in FM-AM receivers will surpass the sales
1962. From this base, the Harvard re- of AM -only sets. By 1968, total FM or
searcher projected advertising expendi- FM -AM receiver sales will have caught
ture for all media from $13 billion in up and passed AM only receiver sales
1963 to $18 billion in 1970 and finally at 11.4 million, as compared to 9.2 milto $20.5 billion in 1973.
lion AM receiver sales.
Using a constant multiple of 5.83 per
Another reason for giving the Harcent of total national advertising ex- vard study credence was that the study
penditures (for rate of growth) for both predicted a sale of 3.36 million FM sets
AM and FM, the Harvard report showed in 1963, 4 million in 1964, and 5.75 milthe future of combined AM-FM radio lion in 1965. Actually, 5 million sets
growing from $762 million advertising were sold in 1963, and sales could easily
revenue in 1963 to $1,198,000,000 in reach 6.4 million units for 1964.
1973.
So far, the evidence demonstrates that
The Harvard report becomes even the Harvard predictions have been conmore significant and believable because servative. Sales of FM receivers are alits projections were based only on ready a year ahead of what Harvard
growth of independent FM stations and projected.
did not include figures for combined
Another trend line, perhaps not too
AM -FM outlets, which represent a much important because of the three -year-old
more significant financial element in the freeze on new AM licenses, is the sale
radio industry today. Added impetus of transmitting equipment to the broadfor FM's separate growth should come casting industry. Last year, sales of FM
from major radio stations in our large
and of AM transmitters were about equal,
cities.
transBy 1973, according to the Harvard but by 1965 sales of FM station
60
per
expected
be
about
to
mitters
are
predictions, the growth of FM will be
Apsales.
of
AM
transmitter
cent
ahead
spectacular. FM radio revenue will then
stand at $374 million as compared to parently, the radio industry, too, beAM's $500 million plus. The pivotal lieves the future of FM is good.
Another important aspect of the Harmoment for FM comes in 1974 when its
This ruling was generally interpreted as
an attempt to promote wider station
ownership and a broader spectrum of
programming, which might include more
adult programming and also break up
the semi-monopoly that the major networks have had in most big cities (not
to speak of the hinterlands).
The FCC seems to believe that FM has
arrived. This ruling could supply a much
needed impetus by relieving FM of its
Cinderella role with respect to AM radio.
being used as a give-away
No longer
to sell or reinforce its AM sister and
sitting at the hearth forced to mouth her
every word (or sound).
...
...
AUDIO
FEBRUARY, 1965
CROSS FIELD ADVANCES TAPE TECHNOLOGY
President
Duplicators
By Cliff 147heninouth,
11agncAtic Tape
An audio engineer reports on the capabilities of the Cross Field Concept
Is the Cross Field concept of tape
recording a "gimmick"? Or is it, indeed, the long- sought -after solution
to the problem of high frequency
losses at slow speeds? Along with
most audio men, I have watched the
performance of the Cross Field concept closely since its introduction a
year ago. After exhaustive testing
in the studio, in home sound systems
and out in the field -there is no doubt
but that the Cross Field is a brilliant
success.
As applied by Roberts Electronics,
in that firm's Cross Field Model 770
-
4 -track
stereo tape recorder, the
problems of loss of high frequencies
at slow speed and of excessive head
wear are neatly resolved. In fact, the
performance of this remarkable
instrument may very well set a new
standard for the entire tape recording
industry!
Unique Cross Field Head
Assembly
To achieve its high frequency response
at slow speed, the Roberts Cross
Field 770 employs an unique recording and playback technique involving
three heads:
RECORDI
ERASE
CURRENT
CROSSAIELD NEAR
ASSEMBLY WRING
BIAS
CURRENT
RUNBACK SIGNAL
VOLTAGE
2.041;-°02t4'.
1.
A conventional Erase Head,
which erases the tape immediately
prior to recording, as is normal
practice.
2. An
extraordinary Record /Play
head with the highest resolution
in the industry -a gap width of
only 40 millionths of an inch.
During playback, the narrow gap
width picks up the very short
recorded wave lengths necessary
to provide high frequency response at 1%8 IPS. (These short
wave lengths cannot be picked up
by wider -gap heads in conventional recorders.)
3. The unique separate Bias Head
which provides the bias field during recording, and which automatically swings out of the field
during playback. The tape never
touches the bias head, which is
therefore not subject to wear.
Opens Another Octave in High
Frequency Spectrum
The correct blend of bias and recording fields accounts for the remarkable
performance of the Cross Field concept. In the Roberts 770, an entire
octave in the high frequency spectrum, which has never before been
captured on tape, is recorded and
played back. (Other recorders, by
combining the recording and biasing
functions in a single head, erase these
high frequencies as they are recorded.)
Frequency response of the Roberts
Cross Field 770 has been established
as follows :
at 71/2 IPS -from 40 to 22,000 CPS ± 2dB
at 33/4 IPS -from 40 to 18,000 CPS ± 2dB
at 17/3 IPS -from 40 to 13,000 CPS ± 3dB
Pure Stereo at 17/s IPS
With a frequency response of 40 -13K
at 17/8 IPS, the Cross Field 770 advances tape recording technique into
the realm of long-play stereo. In test
after test with the Roberts instrument, brilliant stereo sound was
achieved at the 17/s speed. Recording
4 -track stereo at long-play speed, the
equivalent of 18 stereo tape cartridges-up to 8 hours of stereo play
-were recorded on an ordinary 7"
reel of tape. Long -play stereo is
indeed a reality!
Heat Problem Also Solved
With the longer in -use periods normal for the Cross Field 770, Roberts
has also solved the problem of heat
build -up. Their newly -patented
blower ventilation system is, in itself,
a revolutionary development in electronic cooling.
New Drive System Designed
A new motor and drive system developed by Roberts for the Cross Field
770 reduces wow
& flutter at all
speeds to a minimum. W &F at 17/s
IPS is less than 0.30% rms. Roberts
employs a heavy -duty hysteresis synchronous motor with an electrical
speed change, a refinement usually
found only in the most costly professional recorders.
Many Other Sophisticated
Features
The Roberts
rmit
Cross Field
770 is a highly
sophisticated
instrument
with such pro-
'
fessional features as automatic all -off /
shut -off and
pinch wheel release; cathode follower
pre -amp and 8 ohm speaker outputs;
two self-contained 5 x7 stereo speakers; mute -monitor Public Address
switch; pause lever; 4 stereo headset
and speaker outputs; exclusive
Roberts multiple adjustment head for
precise selection of all record /play
functions; new high -speed fast forward /rewind (1200' in 75 seconds);
horizontal or vertical operation.
Roberts Cross
Field 770 is priced
at $499.95 (slightly
higher in Canada),
and is available at Roberts Franchised
Dealers throughout the United States
and Canada. Currently the world's
first hi-fi stereo 6 -hour LP tape (a
valuable Collector's Album of music
by famous artists reproduced on the
new MTD Biasonic Duplicator ) is
being given away free with each Cross
Field 770.
See and hear the Cross Field 770
demonstration at all Roberts Dealers
throughout the United States and
Canada. Or write direct to the plant
for complete information.
Roberts Electronics, Division of
Rheem Mfg. Co., 5922 Bowcroft St.,
L. A., Calif. 90016. Dept. RT-9
In Canada: J. M. Nelson Electronics, Ltd., 2149
Commercial Drive, Vancouver 12. B.C.
ROB E RTSB'ñ
Circle 118 on Reader Service Card
AUDIO
FEBRUARY, 1965
37
www.americanradiohistory.com
AmericanRadioHistory.Com
yard study was their look at operating
costs and station profits. After many
years of genteel poverty, the Harvard
study predicts, FM radio will for the
first time in its history pull out of the
red and put black ink on its ledgers.
Over 400 independent FM stations will
have a profit of $1,500 per average station. The number of FM stations will
grow at about 15 per cent a year (this
has been the growth rate starting in
1958) to 2,000 in 1966, to 2,200 in 1967,
and ultimately to a total of 3,200 stations in the early 1970's.
The Present -and Future
What is the current FM situation? In
March of this year there were 1,159
licensed and operating FM stations, an
increase of 67 over a year ago.
Advertising billings this year were $40
million as compared with $13.5 million
a year ago. Next year, they are expected
to jump dramatically to at least $100
million.
Already, 555 AM -FM stations are programming separately. As of July 1, over
300 stations were broadcasting stereophonically (multiplexing). Equipment
manufacturers have a huge backlog of
orders for new transmitters capable of
broadcasting stereophonic sound.
Why do FM's future advertising prospects look so good? Many alert advertisers know that advertising and marketing have become, for many products,
highly selective. This means a marketing
strategy aimed at a highly segmented society for many products. The advertising
trade journals are filled with the need to
talk to people in terms of their special
interests. Marion Harper, President of
Interpublic, the largest advertising
agency in the world, put it thus : "segmented marketing is taking over
its
strategy recognizes that markets are
people -with individual characteristics.
(It) focuses on differences in tastes,
habits, beliefs."
Only the biggest companies can afford
to blanket all major media with their
advertising. A segmented marketing
strategy is a must for the advertiser who
must spend his money judiciously.
Up to now, the biggest hurdle faced
by FM radio has been selling the major
advertising agencies and their clients on
its special marketing and advertising
virtues. FM radio has lacked the research-managerial -entrepreneural talent
and the capital to match its superior
sound and its sometimes superior programming for the class mass market.
Too often, the average FM station has
been run by dedicated people with
limited resources.
The major networks, impressed by the
easy profits of TV, have seen the growth
of their network radio advertising revenue in AM dramatically declining. Noticing this, they have not invested money
...
in AM and certainly they have not been
inclined to put their best foot forward
in programming even when they program separately. The independent FM
stations, have led the way usually by
programming for select audiences, their
true metier. But often they have sounded
off -beat, perfunctory, and as canned classical juke boxes, pretentious and
boring.
One of their greatest shortcomings
has been in the area of the background
informational coverage and news available to the major networks, publishing
companies and other communications
outlets. Also, they have frequently failed
to capitalize on their superior transmitting ability, particularly with respect to
stereophonic sound, in broadcasting live
musical performances. They have failed
to do this because they have not had the
advertising revenue to support this
luxury. So they program records and
tapes instead. The remarkable thing is
that FM stations have given us such
good programming with such limited resources.
As previously mentioned, their financial and managerial talents have been so
limited that they were unable to supply
the magic numbers that Madison Avenue
requires to sell this service to their
clients. They have, thus, been caught in
a vicious circle. Without advertising,
they have lacked the revenue to take advantage of their true potential.
Their problem in selling advertising
was well articulated by Herbert Zeltner,
Vice President and Director of Media at
Lennen and Newell, a large advertising
agency. He said : "There seems to be a
school of thought which calls for numbers, numbers and still more numbers.
Good, bad or indifferent, some buyers of
media just want statistics for use as a
crutch when making recommendations.
Or the assumption that any number, no
matter how dubious its origin, is better
than the exercise of judgment." He
might have added that in today's big
business organizations very few business
bureaucrats want to stick their necks
out too far, even though we know a
turtle only makes progress when his
neck is out.
However, several studies done in the
last few years by agencies, companies
and the FM industry itself are beginning
to refute the fashion of a few years ago
which was to write FM radio off as a
nonexistent or a mysterious medium
existing on a fringe of more normal
availabilities.
Here are some statistics the marketing
world has found hard to ignore :
Sets sales increasing 25 times within
the last eight years.
An average penetration of over 42 per
cent in the 10 leading cities in the U.S.
For example, 55 per cent in New York
City; 45.3 per cent in Los Angeles;
44.7 per cent in Chicago.
A separate and distinct medium, which
is an unduplicated audience as far as
radio is concerned. (51 per cent of FM
listeners do not listen to any AM
radio.) FM listeners are poor TV viewers which makes them good for the
advertisers who want to reach an audience not well covered by TV.
Pulse, Incorporated, in a 1961 study,
showed that in the top ten markets
there are close to 10 million FM receivers-66 per cent turned in weekly.
76 per cent of the homes with FM receivers have incomes of up to $15,000
and over.
60 per cent have incomes from $10,00015,000.
FM's audience in New York City, the
largest radio market, is larger than
Chicago's (the second largest radio
market in the U.S.) combined AM -FM
audience.
The conclusion of current research
shows clearly that FM must be bought as
a separate advertising medium. Its use,
according to Zeltner of Lennen and
Newell, must be "planned for by the
media supervisor to fulfill completely
different strategic objectives than those
usually assigned to AM radio." This may
not always be true because FM shows
signs of becoming the class mass market
of the air and well worth considering as
a separate mass market.
Reactions
Not everyone in the radio industry is
happy about the growth of FM, long considered the caboose on the train. Some
forces would like to have the FCC reconsider its recent ruling. For instance,
CBS objects, saying that it will discourage diversity and lower the quality of
non-musical fare on FM. The National
Association of Broadcasters, according
to Electrical Merchandising Week, says
"FCC has pre -empted a management decision that must be based on whether the
FM station can independently generate
advertising revenue to support separate
programming." One can appreciate the
dismay of the major radio-TV operators
as they watch their recent prodigy, Television, syphon off advertising revenue
from their older child, AM network
radio. However, it must be pointed out
that total billings of radio today exceed
those of radio pre -TV. This is because
of the growth of local radio and national
spot radio.
A quick spot check by this writer
showed schizoid tendencies among major
operators on the new FCC ruling. Here
is how one of them responded to a query
on the ruling "This hurts. Now we have
to invest more money for this separate
programming though for years we have
not made much money with AM network
:
AUDIO
38
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 19651
don't let
the price tag fool you!
THE NEW ELPA PE -34 IS A LOT MORE TURNTABLE
FOR A LOT LESS
MONEY... ESPECIALLY WHEN
YOU REVIEW THE FEATURES!
The NEW ELPA PE -34 4 -speed Turntable
combines features that up to now were found
only in higher priced professional transcription -type turntables.
Features like: Belt PLUS idler wheel drive
the reason for the low, low rumble) 4 Speeds
Built -in lowering (cueing) device that saves
record and cartridge wear
Powerful fourpole induction motor (with plenty of Torque)
Heavily weighted, non -magnetic Turntable
Vernier speed control Rugged, precisionbuilt professional type tone arm.
What do all these features add up to?
The Elpa PE -34 not only meets, but exceeds
the National Association of Broadcasters
(NAB) specifications required for profes-
sional use in broadcast stations.
That means the NEW Elpa PE -34 will satisfy
your strict requirements too. AND not because of price either.
Examine these Specifications:
PLATTER & DRIVE SYSTEM
A heavy -duty precision-built 4 -pole induction motor floats in a triple rumble isolation
system.
A heavy
cast and machined non -magnetic
platter on a precision bearing assures accurate speed and minimum wow and flutter.
A vernier speed adjustment (3%) for perfect pitch or "tuning" the turntable and
record for perfect pitch or any accompanying musical instrument.
TONE ARM
The specifications prove it: There's a new
concept in turntables -the PE -34 (backed by
50 years experience)
just like other Elpa
Marketing Industries products that have set
new hi -fi standards.
...
Low resonance balance arm with double
precision -bearing suspension (vertical and
horizontal planes) minimizes arm drag.
Don't let the price tag fool you ... you can't
do better at $72. (± $25.00 or 35 %)
All modern cartridges can
Stop in at your Franchised Elpa dealer and
ask to see the new PE -34 in action.* Price
includes: Full Year Guarantee, Strobe Disc
and 45 rpm adapter. Satin Walnut base optional at $6.00. Base dimensions: 4" High x
15" Wide x 121/2" Deep.
be easily mounted
in a cartridge mounting slide.
Complete 4 -wire system.
Cartridge mounting slide pulls out for quick
stylus inspection.
Built -in spring loaded stylus pressure adjustment gauge.
NEW DUST COVER AVAILABLE!
Style PC -34 Sturdy Plexiglas'
$9.00
CONTROL SYSTEM
Automatic tone arm lift at end of record.
Semi-pneumatic cueing and indexed (7 ",
10 ", 12 ") tone arm control at start or at
any point during play.
Automatic fool -proof glide to and from
record groove.
Cueing lever incorporates positive tone
arm lock.
PHYSICAL DIMENSIONS
Width: 13"
Depth: 103/4"
Height: 3" above mounting board
33/4" below mounting board
Ff
<\
PERPETUUM -EBNER
a
not division of
Elpa Marketing Industries, Inc.
New Hyde Park, N. Y.
Circle 119 on Reader Service Card
AUDIO
FEBRUARY, 1965
39
radio." For those who own TV stations,
there is an added complaint : "Along
with this increased investment in FM
programming and stereo equipment, we
also have to invest more money in color
TV transmission and programming.
Such are the pangs of progress. If one
looks at the balance sheets of combined
AM -FM and TV properties, it is evident
that the major owners have not been
doing badly.
The Advantages of FM
Behind all the commercial facts and
figures, the biggest factor that has led
to the incipent FM boom has been the
essential satisfaction of many a listener.
One of the virtues of FM radio for the
listener, up to now, has been its very
lack of advertising clutter. This lack of
advertising clutter and the taste of its
advertisements, as compared to AM, has
been apparent to the listener and is now
becoming apparent to the advertiser.
With prosperity perhaps just around the
corner for some FM stations, their owners will be hard pressed to abandon the
previous standards of advertising spacing.
A combination of good sound, good
talk, good music and a modicum of cerebral content has attracted an ever-growing number of better-educated, betterheeled listeners. Too much of AM radio
today has abdicated to "Formula Radio
in the Pursuit of the Big Beat," the title
of a recent article by Richard Doan,
editor of the New York Herald Tribune
Radio and TV Guide. Of course, there
have been some outstanding exceptions
in this field, WOR in New York and
KNOX in St. Louis among them, found
success with what the trade calls "the
talk formula."
For many years, the better educated
and literate portion of radio's audience,
not finding what it wanted musically on
AM radio, has been retreating to records,
tapes and hi -fi equipment. Various marketing and media studies show that hi -fi
stereo equipment is one of the most popular of semi-luxury products, particularly
among magazine audiences.
But the general public and even musicians have had to educate themselves
to appreciate wide frequency ranges. In
1945, the general public voted against
hi -fi five to one. Surprisingly, even musicians have been unappreciative of
wider frequency ranges until recently.
Many studies show that growing to appreciate better sound is, for most people,
a learned response.
Roger Kirk of Ohio State recently
confirmed the result of the pioneering
CBS test in 1945 which showed that
People when exposed to three systems of
musical frequency responses: One, a
wide range of 40-10,000 cps; two, a
moderate range of 80-7,000 cps; and
three, a restricted range of 180-4,000
40
cps (approximately AM's usual frequency response), preferred the restricted range system.
However, Kirk went further than most
researchers in the field of psycho-acoustics. For six weeks, Kirk exposed one
group to a considerable amount of wide
range listening, another group to medium range listening, and the third
group did no test listening. The original
test was given again. Now the wide range
group liked better sound, the mid -range
group liked better sound, but the third
group had not changed its opinion.
Other recent tests have demonstrated
the same appreciation -learning phenomena are true of stereophonic sound.
Most people prefer the familiar. It takes
a little time and exposure to appreciate
FM or its latest refinement, FM stereo.
As some wit described it: "We are
usually down on what we are not up on."
It takes an educated ear to appreciate
better sound.
Some FM broadcasters realize that
superior sound is one of their strongest
listener appeals. Stations, recognizing
this, have been going stereo at the rate
of three a week since the middle of September last year. For example, in the
larger markets such as Los Angeles and
New York, there are already over 15
stations broadcasting stereophonically
either full time or part time.
The National Association of FM
Broadcasters expects 150 new stereo
program sources to be available to the
listener in 1964. Transmitter manufacturers report a backlog of orders from
32 stations for stereo transmitting equipment.
Most new stations start up fully
equipped to broadcast stereo. WTFM in
New York, a station only 21/2 -years old,
has since the start programmed its entire
broadcasting day in FM stereo. Result:
it has already captured the largest FM
audience of any strictly FM station in
that area. In some instances, it has already begun to crowd the leading AM
stations in terms of its penetration of the
New York Metropolitan market.
Perhaps part of the reason for FM's
success is that it is a new gadget. We
are a gadget -oriented society. For example, there are already 91/2 million stereo
receiver sets in use, and they are among
the hottest items in department and
radio-TV stores. However, stereo is more
than a fad, just as color TV is more than
a fad. Stereo gives added dimension to
sound as color TV gives an added dimension to visual images.
The serious music lover has up to now
generally been more interested in the
musical content rather than in the sound.
But even this audience has succumbed to
the virtues of stereo, realizing that no
one has yet been able to separate sound
from music. A good performance is only
enhanced by improved sound. Edward
Tatnall Canby stated the new attitude
of the musically literate when he said,
"I myself am a music lover and a musician who is so thoroughly convinced of
stereo's values in purely musical terms
that I rarely hear any recorded music in
other than the stereo form these days.
When I listen to a monophonic disc now,
it honestly sounds strange to me, false
and lacking in realistic impact, until, of
course, I re- adjust my ears to its musical
values."
Stereo's better sound values improve
all music whether it is a solo piano, a
solo guitar, or a full symphony orchestra. It brings out the subtleties of musical composition by adding an infinitesimal but very important quality of
separation even of musical tones in a
solo instrument, the separation that
every living performance has. It gives
you clarity of musical texture which the
living performance has. Even the piano
sounds better when compared with the
monophonic reproduction. To quote
Canby again on stereo's values "Stereo
produces the separation which makes a
group of first violins sound as a body
yet minutely separate, indetectably so,
but over -all more life -like in imaginative
terms than any monophonic group of
violins could ever sound." Here it must
be said that all stereophonic sound has
not been an improvement. Much recorded
sound is horrible and mediocre, designed
just to exploit the musically uninitiated.
In sum, FM radio is but one beachhead of excellence in our society. And,
its long -range future will remain problematical until the leaders of America's
communications industries see in it both
a challenge and an opportunity. But,
it would appear that FM is about to
reap some financial success after many
years in financial purgatory. After horrible birth pains, such as having its band
suddenly shifted to another portion of
the broadcasting spectrum, an FCC decision which almost overnight antiquated
eight million FM sets, its new -found
prosperity can be largely explained by
one fundamental thing: Its superior
sound and technology. Many astute observers believe that FM stereo is on its
way to becoming the dominant broadcasting medium.
Technologically, FM has been an integral part of many recent electronic advances. FM will also soon span the entire
world as the carrier wave for all satellite
and space communications. Already all
microwave relay is on FM multiplex, all
tropospheric scatter transmission necessary to military networks is FM. The
reason is simple. FM is the superior,
static -free, high -fidelity transmission system. FM's great opportunity lies in the
American education explosion. America
represents the largest class mass market
(Continued on page 53)
AUDIO
FEBRUARY, 1965
EASY to LOCATE and AIM Jensen
C
SPEAKERS with
ISOSONIC CONTOUR TEMPLATES
SIMPLE AS
1
-2 -3!
Place chart over elevation view (any scale)
with origin at tentative CALSTAR location.
Tilt slightly and shift up or down to cover
largest possible audience area within least
number of zones.
Each zone between any two Isosonic Con-
tours provides sound level variation of no
more than 3 decibels.
Jensen Isosonic Contour Charts are 14" x 20"
transparent plastic templates for Jensen
CALSTAR
Column Speakers Model 55 and Model 1010. Set
of two templates in mailing tube, $1.00 postpaid.
Write for Jensen Technical Bulletin No. 45.
JENSEN
LOUDSPEAKERS
Choose Jensen CALSTAR Column Speakers to assure
the uniformity of coverage angle throughout the frequency range so necessary for uniformity of sound quality
and speech intelligibility (understandability) throughout
the audience area.
Use Jensen Isosonic (equal sound) Contour templates,
to quickly and accurately determine the location and
aiming angle to acheive the desired uniformity of sound
level.
Determine speaker layout to meet desired coverage in
minutes -no longer need you spend tedious hours checking levels at various distances and for various angles at
several discrete frequencies -or worse yet, guess what may
work.
JENSEN CALSTAR Controlled Angle Lobe Suppressed Twin-Array Reproducers are the unique
new column speakers using special "shaping networks" to control the radiation patterns of two line
sources (woofers and tweeters) to acheive constant
vertical coverage angle throughout the frequency
range of interest and thereby attain uniformly high
speech intelligibility throughout the audience area.
MODEL 55 (left)
10- Element
Twin -Array
60 °, 30 -Watt, 8 -ohm
Column Speaker.
List $133
MODEL 1010 (right)
20- Element
Twin -Array
30 °, 60 -Watt, 8 -ohm
Column Speaker.
List $233
JENSEN MANUFACTURING COMPANY / DIVISION OF THE MUTER COMPANY/ 6601 SOUTH LARAMIE AVENUE,
CHICAGO 38, ILLINOIS
Canada: Radio Speakers of Canada, Ltd., Toronto
Argentina: Ucoa Radio, S. A., Buenos Aires
Mexico: Fapartel, S. A NaucaIpan, Mex.
,
AUDIO
FEBRUARY, 1965
Circle 120 on Reader Service Card
41
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AmericanRadioHistory.Com
Jlíi1IT
®
.oO
N10'111
o0
®
o
E
McINTOSH FM- STEREO
TUNER, MODEL MR 71 and
as to be faster acting when one tunes
off a station. The second limiter feeds
SOLID -STATE STEREO
PREAMP, MODEL C 24
the signal discriminator in the usual
fashion. The multipath distortion indicator now serves only one purpose
meters indicate signal strength and tuning-and does not have to be switched.
The recovered composite signal feeds
the MX amplifier, with 19 kc appearing
in its plate circuit while the audio appears at the cathode, whence it goes
through the new SCA filter and thence
to the decoder.
The SCA filter is undoubtedly a very
complicated device, since its response
curve drops at the rate of 275 db per
octave beginning at 54 kc, reaching an
attenuation of 50 db at 60 kc and remaining flat at 50 db to beyond 74 db
where it rises some 10 or 15 db to about
85 kc before falling off gradually. This
filter was computer -designed, has no adjustments, and effectively eliminates any
SCA interference without affecting the
flat transmission of the stereo subcarrier up to the limit at 53 lie. Because of
its sharpness, this filter remains in the
circuit at all times, thus eliminating one
more switching operation required on
some tuners. The decoder circuitry remains the same, and the MR 71 retains
the dual outputs-one of "fixed" level
and one variable, controlled from the
front panel.
The 19 -ke pilot signal, aided by some
audio derived from the first discriminator, actuates the stereo indicator light
amplifier which, in turn, drives a transistor which actually turns on the indi-
The MR 71 FM- Stereo Tuner
In February, 1964, we profiled the
McIntosh MR 67 Stereo Tuner, and
during the course of the description it
was stated that it "is unexcelled by any
other tuner we have had occasion to test
in recent years." This is no longer true.
It is excelled by the MR 71. Of course,
it should be, since the MR 71 is essentially the same as its predecessor (in
time, since both are now in the line)
with minor improvements which are the
result of continuing development work.
When one reads the specifications, one
finds comparatively little difference between the two models with respect to
performance. The MR 71 has a slightly
better capture ratio of 1.5 as against
1.7; it employs five i.f. stages instead of
four; it has 8 db more suppression of
the multiplex products (primarily because of the new, extremely sharp SCA
filter), different tuning indication, automatic stereo -mono switching, and three
extra pounds of weight. It still uses a
6DS4 Nuvistor combined with 1/2 of a
12AT7 as a cascode front end, albeit it
does use top -end inductor coupling between the first two tuned circuits instead
of an inductive link. The principal differences begin with the fourth i.f. /first
limiter which feeds a first discriminator
used to control the muting circuit which
acts upon the fifth i.f. /second limiter so
-
Fig. 1. McIntosh
FM-Stereo
Tuner,
Model MR71.
cator in the presence of a stereo signal.
A second light in parallel with the first
illuminates a Raysistor in the cathode
circuit of the 38 -kc oscillator, turning it
on or off without any audible sound and
without any attention from the user. A
front-panel stereo -mono switch disables
the switching circuit when it is desired
to receive mono exclusively, although
the indicator light still functions. The
remaining front -panel controls are a
variable afc and muting on /off. Sliding
the whole chassis forward in its Panloe
mounting (so glowingly described in the
profile of the MR 67) provides access
to a slide switch which controls panel
light brightness.
The rear apron mounts the 300 -ohm
antenna terminals, 75 -ohm coaxial antenna jack, the "fixed" and front- panelvaried audio output phono jacks, the
output- adjusting dual pot for the
"fixed" outputs, the muting adjustment
control, power fuse, a.c. receptacle, and
one of the two test points to which the
MI 2 Multipath /Tuning Indicator accessory can be connected (the other
connecting point is on the top of the
chassis). This device employs a cathode ray tube in an elaborate circuit to permit visual monitoring of stereo signals
and multipath interference.
To the casual observer, the MR 71
performs as well as the MR 67, which
is saying a lot. In every category -sensitivity, hum, frequency response, channel separation -there does not appear
to be a great difference. It is more effective, perhaps, in freedom from noise,
but beyond that there is very little difference which is apparent to the ear
and not very much on the test bench.
Where it does excel, however -and this
is apparent to even the non -technical
listener-is in the ease of operation. In
the profile of the MR 67, credit was
given to the unusually high quality of
components and construction as being
the main factor in making the MR 67 a
"superb" product. If there were such
a word, we would only say that the MR
71 is "superber." Beside that, it is most
attractive with its greenish illumination
of dial scales and meters, the green
fluorescence of the multipath indicator
tube, and the red stereo indicator light.
Even the distaff side will thrill over it.
It would be unfair not to mention the
high quality of the Owner's Manual
which accompanies the MR 71. It is
handsomely executed from the graphic
arts standpoint -good paper, good
has a table of
printing and so on
contents on the front, covers technical
description, installation, and operation
clearly and simply, and is well illustrated. Three pages of FM Station Log
are provided in the back, with spaces
for frequency, logging scale, call Ietters,
city and state, antenna direction, and
remarks. Last but not least, in our esti-
-
-it
AUDIO
42
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FEBRUARY, 1965
GYROPOISE' MAGNETIC SUSPENSION introduces a mew perfection to the reproduction of sound. Its
secret is silence! The record platen rides on a cushion of air-suspended magnetically! Mechanical silence is
the result. Vertical rumble is eliminated. But there's much more that recommends this remarkable turntable. It's a matched, balanced, coordinated system, complete unto itself. The arm and platen suspension
have been unified to eliminate all mechanical feedback. The Unipoise® tonearm is balanced from a single
bearing point. Its cartridge -the famous Stanton Stereo Fluxvalve -rides the record with a feather touch.
The motor,' too, is engineered for silence, rigidly mounted to the base to dissipate all possible vibration.
The 800B Stanton Stereotable® System even looks silent. The lines are slim, quiet and functional, with a
base of natural walnut and fittings of gleaming brushed metal. See for yourself -and listen too -at your
franchised Stanton dealer. Stanton Magnetics Incorporated, Plainview, New York.
STNTOH
AUDIO
FEBRUARY, 1965
Circle 121 on Reader Service Card
43
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AmericanRadioHistory.Com
Fig. 2. McIntosh
C24 Solid -State
Stereo Preamp.
mation, is the inclusion of a schematic.
Though all audiofans do not do their
own servicing, it is not likely that any
technician called in would have a schematic at hand, and if the owner can
supply one, so much the better. We feel
that a schematic should always be included with any hi fi tuner, amplifier, or
receiver.
The C 24 Solid -State Stereo Preamp
This unit is being included with the
MR 71. tuner profile because a preamp
is generally used in conjunction with a
tuner, because it is very similar in appearance, and because its performance
is similarly superb.
The McIntosh C 24 employs a total of
18 silicon planar transistors-eight in
each of the two channels (which are
identical), one in the "center-channel"
(L +R) output, and one as a voltage
regulator in the power supply section.
The phono/tape head preamp employs
three transistors, with RIAA or LP
equalization selected for phono by a
slide switch, followed in turn by the
mode- selector switch, loudness control,
channel balance, the first section of the
volume control, and an emitter -follower
which drives a Baxandall -type tone -control circuit. This is followed by two
more amplifier stages, the rumble and
noise filters, and the output amplifier
using two transistors. The second section
of the volume control is next, followed
by a voltage divider/mixer network
feeding the L + R amplifier stage. Two
silicon diodes serve as the power rectifier, and the voltage is regulated to 75
volts by the 18th transistor, and further
regulated to 10 volts by a zener diode.
A four -second time -delay circuit is provided to ensure that the full voltage is
not applied to the circuit abruptly, thus
allowing the various capacitors to
charge up without the usual annoying
"thump" which is generally heard when
a non -delayed transistor amplifier is
first turned on.
So far, nothing particularly new or
startling has been said about the C 24,
which is as it should be. What is unusual about the over -all philosophy of
the C 24 is the channeling of the power
amplifier output through the preamp
chassis before going to the loudspeakers.
This feature is to permit switching of
the speakers, as well as to provide a
panel -mounted jack for headphones, and
to permit reversing the phase of one
speaker from the control position,
rather than in back of the speaker itself,
which is often enough of a chore as to
preclude its being done, even when it
might improve the listening. (Not all
sources -tape, records, or broadcasts
are always perfect in this regard). In
less careful design, this proximity of
high -level outputs might cause trouble,
but in this unit the shielding effectively
precludes any trouble from this arrangement.
With the speaker switch, headphone
jack, and phase -control switch at the
control center of his system, the user
has almost every possible flexibility that
he might need -or want. This feature
has been encountered before in receivers, but so far we have not seen it in a
preamplifier /control unit.
-
Performance
There is little need to state that the
is flat within 0.5 db from 20 to 20,000 cps or that the equalization curves
follow the prescribed values within ± 2
db throughout the audio spectrum-we
have learned to expect that from any
good preamp over the past few years
but the distortion figures are somewhat
remarkable. The output is rated at 2.5
volts, and at this value the distortion is
less than 0.1 per cent from 20 to 20,000
cps. Even at a 10 -volt output the distortion measures less than 0.3 per cent
over the same range. What is especially
important is the amount of phono (or
tape head) input this unit will handle
without clipping. We have learned by
now that this is one figure that should
be measured first in any test of transistor amplifiers.
Before describing the phono performance of the C 24 in this respect, let us
examine the possible amplitude of the
signal from a modern pickup cartridge.
We have actually measured stylus ampL.tudes of more than 40 cm /sec on
some phonograph records-not many,
we'll admit, but on some. The usual output from a stereo cartridge is in the
vicinity of 1.0 to 1.5 mv per cm /sec of
C 24
-
stylus velocity-some as much as twice
that. We have been told by some record
companies that their peak recording
level was 5 cm /sec, (which we do not
believe), and by others that the average
level was 5 cm /sec. Assuming it is average, and with an estimated increase of
peak over storage of 10 db, this would
mean a peak level of 16 cm /sec. A clearance of 16 db is usually considered safer
as the margin between average and peak
program levels, which would imply that
peak velocities of 30 -35 cm /sec could be
reached easily. At an output from the
cartridge, of, let us say, 1.1 mv per cm/
sec, this would mean that the signal applied to the input of the preamp could
reach 33-38 mv. Now if the preamp
should clip at an input of 30 mv (we are
speaking only of a 1000-cps signal) distortion would certainly result. With the
high -frequency boost in modern recording techniques, more efficient microphones in the high -frequency region,
and the inclination of A and R men to
feature trumpets and strings, overload
of the preamp can cause breakup which
is extremely unpleasant.
None of this is likely to occur with
the C 24 because under the worst combination of volume and loudness control
settings, the preamp will not clip (at
1000 cps) until the input signal reaches
100 mv. Under most conditions of settings, the clipping level is 135 mv.
Equalization takes care of the high frequencies, and rolloff of the bass in the
recording process takes care of the low
frequencies. We feel this is a most important problem, and it seems to have
been solved in the C 24 quite satisfactorily. At least, we have not ever heard
any evidences of clipping on phono. We
can not see much application of the 10volt output capability of the C 24, but
if it can supply this much signal with
less than 0.3 per cent distortion, it
should be able to coast along nicely at
the usual 0.25 to 1.0 volts required for
normal room levels.
From its Ivory tower, McIntosh modestly claims 99.9 per cent perfection
we'll give 'em only 99 " /loo per cent.
We would make only one minor change
-that of reversing the direction of rotation of the contour control. At present,
clockwise rotation increases the amount
of equalization, but decreases level. We
would prefer it the other way. In the
maximum position, there is a boost of
approximately 10 db at 30 and 10,000
cps with respect to 1000 cps, which follows general contouring practice.
Tone controls give a range of ± 18 db
at 20 and 20,000 cps. Lo -cut starts at
about 100 cps and its down 11.5 db at
30 cps, 32 db at 10 cps. Hi -cut starts at
3000 cps and is down 7 db at 10,000
cps, 16 db at 20,000. In the flat position
of all controls, over -all response is down
-
AUDIO
44
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AmericanRadioHistory.Com
FEBRUARY, 1965
If it wasn't for this
monstrous 1,400 lb., $1,740
"Voice of the Theatre "®
A7W, A7-500W
you could probably never afford to enjoy the no- compromise big sound of
these
IKC Ç speaker systems from Altec
FULL-SIZE LP
Because their no- distortion mid -range (with
highs and lows to match) which embraces 90%
of all musical material would be beyond the
reach of anybody except people in the industry:
the recording and broadcast studios, and the
networks. Most of whom use them. (Who else
in the hi -fi industry can make a claim like this?
Manufacturer A, B, E, F, F, J, K, K, L, P, Q,
S. T. U, W ?)
And maybe even these discriminating speaker
buyers couldn't afford to help us amortize the
research and development costs of developing
So unless you have room for two of our 1,400
lb. "Voice of the Theatre" Systems, we'd suggest you consider the only next best thing:
QLANSKCYY, systems like the ones available to
recording and broadcast studios and you at the
same reasonable, R &D- prepaid prices.
For example, the new Altec 843A "Malibu"
is a bargain at $356.00 because it contains
speaker components that are nearly identical to
our giant two -way theatre models: two low frequency speakers, a horn -loaded high frequency
driver with low crossover, and a two-section
dividing network. The "Malibu" is first and
foremost a beautifully hand -crafted furniture
piece tailored into a space- saving upright walnut enclosure that will do credit to any living
room. For a horizontal version of the same
thing, try the 838B "Carmel" at $337.50. Or,
for $384.00, you can own the new Altec A7W
which is identical, in every way but looks, to
our famous "baby" "Voice of the Theatre': the
like our beautifully furniture- styled 843A "Malibu': 838B "Carmel': and
A7W. Thank goodness they (and you) don't
have to. Theatre owners the world over have
done it already. Ever since 1945, when Altec
introduced the first (and only) commercially available speaker systems approved by the
Research Council of the Academy of Motion
Picture Arts and Sciences.
QLAY6ACY, systems
NEW!
1110A
ó
4.00
`
:
E ` ;s
_
-
i-°
o
Specially designed for people who like over- emphasized instrumental bass.
This extreme low pass filter connects between amplifier output and speaker
input. Suitable for use only with high efficiency speakers. Price: $30.00
AUDIO
A7. The difference is that the A7W comes in
walnut finish, while the A7 comes in a rather
spartan utility cabinet (though at only $288.00
who will complain ?) for built -in installations.
Other full -size Altec Speaker Systems available
from $204.00 for the space- saving 841B `Coronado" to $411.00.
What more can we tell you? Just to "A-B"
these QLANTIMA., systems against anything and
everything you can find at your nearby leading
Altec Distributor's.
In the meantime, get your copy of Hi/Fi
Stereo Review's Great Debate: "Is a good big
speaker better than a good little speaker?" The
affirmative, quite naturally, is presented by our
own Chief Engineer of Acoustics /Transducers,
Alexis Badmaieff. The negative is presented by
a well -known manufacturer of little speakers.
So find out for yourself why full -size speakers
are now the rage. Merely write Dept. A2.
C AL
ALTEC LANSING
CORPORATION
&,`M14 Subsidiary of
LinaTemco- Vought, Inc.
ANAHEIM, CALIFORNIA
Circle 122 on Reader Service Card
FEBRUARY, 1965
45
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6 db at 100,000 cps, if that should
matter to anyone.
On high -level inputs, noise and hum
measured 78 db below rated output with
the volume control at maximum. In the
minimum position of the volume control,
the noise drops to 112 db below rated
output-as it should, of course, since one
section of the volume control immediately precedes the output jacks. On the
phono input, noise measures 64 db below
rated output at the maximum setting of
the volume control. At a volume control
setting which gives an output of 1 volt
at a phono input of 10 mv, the noise
and hum were down 72 db.
With these impressive performance
figures, the C 24 is truly a fitting companion for the "superb" MR 71 stereo
tuner.
Circle 220
only
DUAL 1010
The usual trend for automatic turntable manufacturers has been to build up
their model inventory by adding a "super" changer. Dual has chosen to reverse that trend. The Model 1010 is a
lower -priced version of their "super"
unit, the Model 1009. At $69.50 it is $30
under the top -of-the line.
Naturally, this new unit shares much
with the 1009. It has the same record
changing mechanism, the same heavy duty four-pole motor, and the same
cartridge mount slide. The major differences are that this unit has a lighter
platter and a completely different arm.
The Dual 1010 is a four -speed automatic changer /manual player. Record
change is accomplished entirely with the
center spindle. This spindle has three
arms that support a stack of up to eight
records. At the correct moment the
spindle arms will retract, dropping the
lowest record. To prevent the rest of the
stack from following suit, the spindle has
an expandable collar that grips the
stack above the bottom record and lifts
it slightly before dropping that bottom
disc. All -in -all, a reasonably fool -proof
spindle system that is very gentle on
record centers. This system is dependent
upon record companies that produce
discs of standard center hole dimension
and thickness. Our tests with a number
of contemporary discs revealed no
change problems at all.
For manual play, the large spindle
can be exchanged for a short one. The
automatic spindle has a pin on the bottom that fits a slot in the turntable
spindle hole. With the pin in the slot,
the record release arms are pulled out
and in at the end of each cycle. Thus,
this spindle cannot be used for manual
play (the record can only go down over
the support arms at the beginning of the
cycle). This is no problem since most
people will use the 1010 for automatic
play only, but if you bounce back -andforth from manual to auto, you may find
Fig. 3. Dual Model 1010 Record Changer.
this system somewhat of a nuisance. Of
course, for manual play only, the short
spindle, which simply drops in, solves
all problems.
A switch on the side of the table selects record size. You cannot intermix
sizes in a single stack, but you can play
the three popular disc sizes, 7, 10, and
12 inch as long as segregation is practiced. (Note that this is true of all the
better changers on the market. Ironically,
only the less expensive units can intermix sizes automatically.)
The basic control for automatic or
manual play is a slider of unusual
smoothness. It is possible to activate the
reject mechanism while a dise is playing
at a light stylus force, without the
slightest upset.
The tone arm is quite basic in principle. In this system, the arm simply
hangs from its canted horizontal pivot
without a counterbalance weight, and
a spring is used to pull back and provide stylus force. A screw with a coin
slot located on the side of the arm,
near the pivot, is utilized for adjusting
stylus force. It has click stops at regular
intervals, which are no more than general indicators, since stylus force per
click will vary according to the weight
of the specific cartridge used.
The spring used is linear throughout
most of its range. No more than half a
gram variation may be expected from
top to bottom of a stack of discs. The
spring apparently becomes less reliable
below 1.75 grams; thus, this would be
the lowest recommended force we would
suggest.
Performance
Using
a very-high -compliance
car-
tridge we substantiated the 1.75 minimum tracking force. Less than this,
which the cartridge could do, caused
some nùstracking of heavily modulated
passages. All subsequent tests were made
at 2 grams.
System resonance was at 20 cycles and
was slight. At 2 grams there was no mistracking at the resonance. Bass rolloff
was rapid below this point. It is worthy
of note that the trip mechanism can operate at forces considerably lower than
the arm's capabilities, so no problems
should ever occur on this score.
Turntable flutter and wow were unusually low for a unit in so modest a
price category. Flutter was under 0.1 per
cent and wow was 0.35 per cent.
Total rumble was 35 db below a 3.54
cm /sec, 1 kc stereo signal. This figure
is very close to what we have measured
on top -grade manual tables.
Our sample was 2 per cent fast, under
load, at a line voltage of 120v. The drive
motor proved extremely immune to
minor voltage variations. At 100 volts
the 1010 was 1 per cent fast. At 90 volts
speed had dropped to 0.5 per cent. A
load of several records had no appreciable effect on these speeds. Those who
are familiar with the Model 1009 know
that this unit has a vernier speed adjustment knob that allows you to correct for
speed variation. The 1010 lacks this
feature. However, the speed variations
quoted are quite acceptable for a good
changer.
All-in -all the Dual 1010 impressed us
greatly. It must be considered in its price
category. As such, it represents very
good value indeed. Its performance is
close to a good manual table, the changer
mechanism is of the very best, only the
arm falls short of allowing us to suggest
this unit for the best systems. Although
the 1010 will not get the ultimate from a
cartridge, it is not intended for use with
the ultimate cartridges either; the 1010
is designed for the moderately-priced
system. As such it fulfills its design goals.
Circle 221
"NETWORK" SPARK INJECTOR
With the curiosity indigenous to a
long -time hi fi enthusiast, this observer
was naturally intrigued by the advertisement of this product in the December
issue. "High Fidelity" performance from
an automobile appeared to be a new
category of criteria.
Accordingly we undertook to obtain
one for "test," not knowing just exactly
how one would measure performance of
such a device with the sort of objectivity
we attempt to attain with the usual hi fi
component.
In the first place, installation is
slightly simpler than claimed in the advertisement, since it took just eight minutes to put it in place, connect the four
wires, and start the car-a 4600 -lb 1961
model. It started off immediately, better,
if anything, than usual. Then, before
essaying any long- trips, we "broke it in"
around town for long enough to have
confidence that it would continue to
work-no real problem if it hadn't,
really, since it is only necessary to move
two wires from their usual terminals to
a third one, all of which are readily accessible, to restore the normal ignition
system to operation.
After sufficient local driving to establish confidence, we went on a couple of
450 -mile trips. There was no noticeable
AUDIO
46
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FEBRUARY, 1965
Set in the groove-any groove...
gently!
New Miracord
'18111 single record play turntable operates manually or automatically. Offers new
cueing record band selector. Gently lowers arm and sets stylus in desired band or groove. Includes
famous Miracord features: automatic pushbutton controls, Papst hysteresis -synchronous motor, heavy
balanced turntable platter, transcription arm, four speeds.
Your hi -fi dealer will soon be showing the new Miracord 18H alongside the now famous Models 10 and
10H. Be sure to see it. Price is $119.50 (less cartridge and base). For further details, write direct:
BENJAMIN
Benjamin Electronic Sound Corp. 80 Swaim St., Westbury, N.Y. Sole U.S. distributor
LIWIEMOCOIRD
Miracord turntables, Elac cartridges and other Electroacustic® audio components.
Circle 123 on Reader Service Card
high -quality glass -epoxy plug -in boards
are the type which are commonly seen
in military applications, plugged into a
Blue Ribbon connector. The cost is high
but so is the reliability. The advantage
of this type of construction is the ease
of service and replacement of defective
electronics. The consumer need merely
unplug the defective board and bring it
to the appropriate service station. He
can even perform some elementary
troubleshooting by reversing boards. If
Fig. 4. Network Spark Injector Set
performance difference up to 60 mph,
but above that when acceleration usually
drops off, it was another story. Step on
the gas at 60 and the car simply jumped,
-about like it usually did at 30. With
the usual test figure of time to reach 60
from a standing start, we measured 10
seconds, and another six from 60 to 80,
-sport car performance from the "family sedan." A more important figure for
the user is the gasoline consumption,
which showed an increase of 13 per cent
over the normal ignition system. This
was on a reasonably accurate controlled
test. On a 500-mile trip, one way was
with the Spark Injector and the return
on normal ignition.
We had previously used another type
of transistorized ignition for some 15,000 miles without changing plugs or
points, and both were still like new
no point wear at all. With no stress on
the points they should last until mechanically worn out, but not from pitting of the contacts.
Later we had the opportunity of observing a bench comparison of the
Spark Injector with a normal ignition
system. At engine speeds of over 4000
rpm, the normal system spark became
erratic, and ceased altogether at about
5000. With the Spark Injector, the
spark was still "fat" up to 7000 rpm,
which is well above any speed a normal
engine ever reaches.
With increased gasoline mileage, snappier acceleration at high speeds, easier
starting, and longer spark plug and
point life, we are most enthusiastic over
Circle 222
the Spark Injector.
-
ACOUSTECH III SOLID -STATE
STEREO POWER AMPLIFIER KIT
The Acoustech III is a power amplifier
intended to satisfy the need for high
power at low distortion, and with the
solid-state bonus of relatively little heat.
Imagine a 40- watt -per -channel (rms
mind you) amplifier weighing only 25
pounds. Simply unheard of in a tube
amplifier.
This is certainly one of the new breed!
The Acoustech III features several innovations made practical by solid-state
technology; plug -in printed circuit
boards, direct- coupled circuit. These
48
other manufacturers adopt this approach, it may solve one of the difficulties facing the component consumer:
the general unavailability of service
comparable in quality to the component.
The circuit of the Acoustech III is not
unusual, the output stage being of the
well -known single -ended push pull persuasion, with the drivers in Darlington
connection. Silicon transistors are used
throughout, and the electrolytics are
high -grade units (Acoustech calls them
computer grade). All of the electronics
except for the output transistors and the
power supply are on the printed-circuit
boards.
Although the amplifier we received
was factory assembled (by accident we
were told), examination of the assembly
manual and the amplifier leads us to
believe that it would take no more than
a few hours to assemble. Especially
since the printed circuit boards are
factory assembled even in the kit.
The kit packaging is truly excellent,
encompassing individual bags of components for each stage of assembly, plus
an ample KitKloth to work on. A valuable plus if you must use a furniture finish table as your work bench.
Performance
The Acoustech III is a top quality
performer which meets its published
specifications with ease and then some.
First of all, through the range from
20 to 20,000 cps it provided a minimum
of 40 watts rms before clipping, and
throughout most of the range it provided in excess of 60 watts per channel.
This power was delivered to a 10 -ohm
load, with both channels operating. Distortion at rated output (40 -watts rms)
into a 10 -ohm load was 0.22 per cent at
1000 cps. At 100 cps it was 0.28 per
cent, and at 15,000 cps 0.3 per cent.
Intermodulation distortion with the same
load and using 60 and 7000 cps tones
mixed in a 4 : 1 amplitude ratio was
0.49 per cent at rated power. Square
wave response was truly excellent at
both the top and bottom of the frequency
range exhibiting no trace of overshoot
or ringing. 1.7 volts was required to drive
the amplifier to its rated output. Hum
and noise were 82 db below rated output.
Listening to the Acoustech III proved
to be a highly satisfying experience.
We were especially impressed with the
ease with which it handled transients
and orchestral peaks. We can't recall
having heard such open sound. The
bottom end was truly superb. Altogether
it is one of the most musical amplifiers
we have experienced to date.
We must recommend a modicum of
caution in certain modes of operating
the amplifier. It exhibits an annoying,
but harmless, tendency to pop fuses in
the presence of non -musical transients
which occur when the tonearm is dropped
on a record or when a tuner is scanned
across the dial. Of course, if you use the
III with the Acoustic IV preamp this
is no problem since the latter unit has
a muting circuit built in.
However, we inserted it into our regular setup which has a different preamp
with no muting provision. We managed
to pop several fuses before we learned
to exercise caution.
In sum, the Acoustech III is a truly
first rate amplifier which merits careful
consideration by the perfectionist. In
its kit form it is easily buildable by the
Circle 223
rankest novice.
BENJAMIN STEREO 200 RECORD
PLAYING SYSTEM
The Benjamin 200 is one of those new
record playing systems which include
in one package an automatic turntable,
an amplifier, a control center, and a
handsome case. In this instance the case
is very handsome indeed, as illustrated
in Fig. 5.
The turntable in this system is the well
known Miracord Model 10, which is
certainly one of the finest automatic turn (Continued on page 69)
Fig.
5.
Benjamin
Stereo 200
AUDIO
FEBRUARY, 1965
Mr. Saul Marantz
discusses his revolutionary new
model 10 -B FM Stereo Tuner
Marantz, your new 10 -B tuner is
quite revolutionary. Do you feel it will
obsolete all other tuners?
JIr. Marantz: In one sense, yes. The performance of this tuner is so dramatically
superior to conventional tuners that
anyone who wants or needs perfect FM
reception today has no choice but to use
the model 10-B. Its superiority, however,
does not necessarily obsolete conventional tuners, Rolls Royce, of course,
makes superior cars, but they haven't
obsoleted Chevrolets.
Q. Mr.
superior performance discernible to the average listener?
Mr. Marantz: Very much so. The differ-.
ence is quite dramatic. As you know,
conventional tuners have never been
able to pick up and reproduce broadcasts
which could match the quality of a fine
disc or tape playback system. This has
often been blamed on broadcasting quality. But the new 10 -B disproves this the-.
ory. It reproduces the broadcast of a
disc or a tape with the same clarity and
separation as if played through a playQ. Is this
-
back system proving that broadcast
quality is generally excellent.
Q. Is this true with weak broadcast signals also?
Mr. Marantz: Yes. In fact the model
10 -B will reach 55 db quieting at only 3
microvolts! This is better than most conventional tuners will reach at 1000
microvolts. With a 25 microvolts station
the Model 10 -B reaches a phenomenal 70
db quieting which is about 20 db better
than most conventional tuners can
achieve at any signal strength. This
means that with the Model 10 -B there
will be excellent reception even in fringe
areas, particularly so because of the tun-
er's high sensitivity, its extremely sharp
selectivity and reduced susceptibility to
multipath effects, which on other tuners
cause distortion.
Q. How are such improvements accomplished?
Mr. Marantz: The answer to that question is very complex, because the 10 -B is
far more than an improved tuning system; it is a completely new design concept with many technical innovations
developed by Marantz engineers.
Q. Can you give us some examples?
Mr. Marantz: Yes. The RF section, for
example, contains a balanced- bridge di-
ode mixer
-a
technique used in modern
sensitive radar designs to eliminate a
major source of noise, harmonic distor-
variation of stereo demodulator, which
permits phase correction to maintain a
very advanced order of stereo separation throughout the whole audio band.
tion and other spurious interference.
The whole RF circuit is balanced- tuned,
using a precision tuning capacitor with Q. What is the purpose of the tuning and
four double sections, for further reduc- multipath indicator?
tion of spurious images.
Marantz: This oscilloscope device is
For the critical IF strip, we've devel- Mr.versatile
its single trace tells many
oped the first commercial application of so
understood stories. It shows when
the `Butterworth," or phase -linear fil- easily
is tuned exactly to the center
ter. This new concept provides a number aof station
the passband. The height of the patof distinct characteristics essential for tern
shows the signal strength. The ingood results. The passband, for example, dicator
how much multipath is
is phase -linear for extremely low distor- present, shows
making it easy to adjust the
tion especially at high frequencies
for best reception. It shows if
and it remains essentially phase -linear antenna
the
station
is creating distortion by over at all signal levels.
modulating.
Also, technically informed
Cutoff slopes beyond the passband are
can check stereo separation of
extremely steep, allowing unprecedented users
selectivity; it is much less subject to the transmissions, discs and other sources.
effects of multipath, and it doesn't require realignment with tube changes or Q. And how soon will the model 10 -B be
aging. The old standby coupled IF cir- available in quantities?
cuits currently in use do not have any of Mr. Marantz: The Model 10 -B is a labothese characteristics.
ratory instrument of extremely high
quality which will never be mass proQ. Are there any innovations designed
duced in the usual sense. However, prospecifically for multiplex?
duction has been stepped up fourfold and
Mr. Marantz: Yes. For multiplex recep- all back-orders are now being filled by
tion we've developed our own unique Marantz franchised dealers.
-
-
'._I..IF Passband retains
phase linearity and sharp
slopes at any signal
strength for low distortion, sharp selectivity.
Conventional mutually coupled IF circuits
change characteristics
drastically depending on
signal strength.
MARANTZ, INC., SUBSIDIARY OF
I
II
MARANTZ MULTIPATH/TUNING INDICATOR
Station tuning is simply
Multipath (Ghosts) shows
and accurately adjusted
up as 'wiggles' on the
by centering the trace.
tuning trace. Antenna is
simply rotated until trace
is smooth.
[ SUPERSCOPE
INC., SUN VALLEY, CALIF.
Circle 124 on Reader Service Card
AUDIO
FEBRUARY, 1965
49
www.americanradiohistory.com
AmericanRadioHistory.Com
RECORD REVUE
Edward Tatnall Canby *
Opera by Handel
Handel: Rodelinda: Stich -Randall,
Roessl -Majdan,
Forrester, Young,
Watts, et al., Vienna Radio Orch.,
Priestman.
Westminster WST 320 (3) stereo
(booklet -libretto)
Lord Handel, one of the top "greats,"
wrote forty six operas and this is only
the second to show itself on records
!
here. About time.
The music in all of them is first -rate,
mostly, but as stage productions they
have been entirely impractical -we like a
different kind of opera now. Moreover,
the voice requirements-for castrati,
singing soprano and alto, in the male
leads, for fancy vocal acrobatics largely
beyond our singers' abilities -have kept
producers away from the stuff. But
things are changing. What with our burgeoning male countertenors and rock and -roll male sopranos, the idea of a
soprano -hero isn't so zany any more
-
and the techniques for singing this
Baroque music are definitely on the
return. Also- records make the ideal
medium for the music, what with LP and
stereo, plus bookletfuls of pictures and
background along with the libretto.
This is a happy and effective production, above all sparked by the superb
Stich -Randall, whose voice is as nimble
as a canary's -or an oboe, let's say -and
whose musical ear is absolutely peerless.
The rest of the cast does its best to emulate her leadership as the heroine, Rode linda. (There is a bass, and a tenor too.)
The music is largely a series of recitative (sung) dialogues followed by arias
(complete musical pieces) for solo voice
with orchestra. Each is a gem of music
and the opera can be listened to piecemeal as a six-sided LP concert of Han delian song, loosely tied together by the
classic tragedy of the story, which, by
the way, has a "happy" ending after an
appropriate quantity of wailing and lament. (Quite a gory story, at that, if
you feel like keeping track of it en route
through the music.)
larly ill treated. in smoochy, snail's pace horrors styled like Isolde's.' The little opera has
desperately needed restoration into a proper
historical perspective.
This one does it, at last Just wonderful.
It is light, lively, energetic, especially in the
splendid choruses, in the witches' macabre
scenes right out of "MacBeth" ; the soloists
sing naturally and at a normal "speaking"
speed in both the recitatives and the brief
arias and concerted numbers-the whole thing
moves along briskly with far better effect than
the antiqued and dismally slow earlier ver!
sions.
Even the orchestration benefits. The instru-
mentation, at last -and what a brilliant idea!
no more than the original, without "modernization" Very streamlined, and much of
the music is with simple continuo, just harpsichord and a single cello. The singers perform with zest to this agile accompaniment,
freed of the orchestral encumbrances attached
to so many turgid "modern" versions of the
opera. Here, things really move.
The piece is transformed, mightily. Even
the clumsy plot and text by the ill -famed
Nahum Tate, long reviled as dreadful, here
finds a new respectability ; it is, we find, a
deliberate (and unforeseen) satire, as entrancingly explained in the annotations by Wilfrid
Mellers. The horrid witches with their very
bad English- "Our plot has took. the Queen's
forsook !" -turn out to be much more than
that, a picture of the vindictive, small-minded
common people of the world in the presence
of heroism and greatness, no more than
"middle class Restoration gossips or harridans
who are horrid only because they are grossly
inane." Their famous cackling "ha-ha- ha-haha-" chorus is spine chilling. Dido herself is
the too -noble heroine, victim of her own high minded obstinacy -she will die and that is
that ; Aeneas is a satire on the Restoration
hero, who in real life often had feet of clay
as he does. And the head Witch, the Sorceress,
is Dido's negative number. All perfectly balanced, and surprisingly urbane and literate,
now that we see it anew. The performance
backs up Mr. Meller's thoughts straight
through, note for note.
Afred Deller, of Deller Consort fame, conducts. He never sings a mumberling note.
-is
!
Johann Strauss: Die Fledermaus. Wächter, Leigh, Rothenberger, Rise Stevens,
Konya, Kunz, Majkut; Vienna State
Opera Orch. and Chorus, Danon.
Operatic Armful
Purcell: Dido
Helen Watts,
Bevan et al;
Orch., Alfred
and Aeneas. Mary Thomas,
Honor Sheppard, Maurice
Oriana Concert Choir and
Deller.
Vanguard BGS 70664 stereo
Henry Purcell's superb little opera, England's very first (and written for a pack of
schoolgirls), has long been on a pedestal of
too much fame, like "Messiah" or the Saint
Matthew Passion, or Corelli's "Christmas"
Concerto or "La Folia." They have become
grotesque, one and all, in overblown Romantic
arrangements to which we are still sentimentally attached. Dido's famous Lament, as she
dies of disappointed love, has been particu-
a bit of inconsistency anywhere that I can
hear. Just a whale of a good stereo show and
all the Strauss you can wish for. I didn't even
notice any baleful effects from Dynagroove.
RCA Victor LSC 7029 (2) stereo
With booklet -libretto
one, to my mild surenjoyed
this
really
I
prise. It's terrific. The reason was that on the
face of it this was another of those mixed -up,
mixed -cast affairs, à la Metropolitan Opera, in
which the idea seems to be to get in as many
nationalities as possible in the singing cast,
and (sometimes) as many different styles as
well.
Not so this time. RCA's version, recorded in
Vienna, is beautifully styled and integrated
and the spirit of the whole production is
fresh, energetic and as eloquent as a first night show. The "foreign" names, like Rise
Stevens, are judiciously placed, the high-speed
spoken German dialogue goes to those who can
reel it off just as it should go, and there's not
Virgil Thomson: Four Saints in Three Acts
(Gertrude Stein). Soloists, Cho., Orch. conducted by the composer.
RCA Victor LM 2756 mono.
What a pleasure This ever -zany, utterly
improbable collection of nonsense -English goes
down the musical gullet as smoothly as a
draft of good ale, as sung by the revival
"original cast" in RCA's recording of 1947,
some 13 years after the premiere of the opera
at Hartford, Conn. in 1934. (Do I remember
that occasion All the literary lights of the
U.S. were invited, in honor of Miss Stein, and
my father, whose musical ear was the purest
tin, attended the thing and came back speechless. Went right in one ear and out the other.)
Here's the famous "pigeons on the grass,
alas," sung most delectably in its musical
form, and here is the all -Negro cast (for no
particular reason, except that Mr. Thomson
liked the sound) and the plethora of Saints,
including Saint Theresa I and Saint Theresa
II, as well as Saint Settlement ( ? ?) and Saint
Ignatius, not to mention two characters called
Commère and Compère.
"It was a magpie in the sky," (what kind
of pie -?) carols the Chorus joyfully, and
Saint Ignatius answers, "If a magpie in the
sky cannot cry if the pigeon on the grass alas
can alas and to pass the pigeon on the grass
and the magpie in the sky on the sky and to
try and to try alas the pigeon on the grass
and alas
; whereupon Chorus I and II
say firmly, "They might be very well very well
very well they might be very well they might
be" and "Let Lucy Lily Lily Lucy Lucy, let
Lucy Lucy Lily Lily Lily Lily." Compère then
announces in earthshaking tones, "SCENE
ONE," and Saint Plan says "One and One."
After awhile, Saint Stephen says "Too much
too much" ; but Saint Chavez will have none
of it and remarks, in song, "There are very
sweetly very sweetly Henry very sweetly René
very sweetly there are many very sweetly.
Foundationally, marvellously, aboundingly,
illimitably with it as a circumstance. Fundamentally and saints fundamentally and saints
and fundamentally and saints." After more
of the same, Saint Chavez concludes pointedly, "The Envelopes are on all the fruit trees."
Maybe it doesn't read well, but in Virgil
Thomson's bland, hymn -like, dead -pan music
the whole thing is utterly delightful and the
Negro cast gets the raffishly zany spirit of the
piece just marvellously marvellously marvellously. Best party-record of the year, of the
ear yuf the yeare ruv theyear... .
!
!
Wings of Song
Britten: Serenade for Tenor, Horn and
Strings (1943); Young Person's Guide to
the Orchestra (1946). Peter Pears, tenor;
Barry Tuckwell, horn; London Symph.,
Britten.
London CS 6398 stereo
This is an absorbing record in a historical
sense -for it is, I think, the third successive
recording of the redoubtable Serenade with its
AUDIO
50
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
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THE
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Ask any audiophile about the 6201, 312 and other
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eyes will light up, his praise will sound like poetry.
Now, after extensive testing and experimentation
with new types of cone materials, magnets, voice
coils, even to the most minute part, University introduces Mustang -the first and only line of low-cost
die-cast speakers so uncompromised in construction,
they are unconditionally guaranteed for five years
We invite you to compare Mustang to all other
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FEATURES (a few): Frequency response of unprecedented uniformity -35 to beyond 22,000 cps with
the Model M -12T! Longthrow voice coils for optimum bass with minimum power. New, specially
treated curvilinear diaphragms to prevent undesirable
resonances. All parts electroplated to prevent distortion caused by corrosion. Sturdy die -cast frames for
precision alignment of all parts. Design permits front
or rear baffle mounting. High (30 watt) power handling capacity. Optimum performance may even be
achieved with amplifiers of under 10 watts. Write:
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UNIVERSITY
A DIVISION OF
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Circle 125 on Re ader Service Card
FEBRUARY, 1965
51
www.americanradiohistory.com
AmericanRadioHistory.Com
original tenor, Peter Pears, and the composer
himself conducting. The first version appeared
here as one of the very earliest 78 rpm London albums, soon after the war. I have never
forgotten that album's music, which convinced me that the Serenade is one of the
masterpieces of the 20th century.
There was an LP version, I think, with Mr.
Pears a little older ; now comes the stereo
version, still with the same singing voice. But
Peter Pears is some twenty years older now
and time has begun to tell. The horn solo
in this recording, Barry Tuckwell, is astounding. (Who says the Brains, Aubrey and Dennis, were the end of a dynasty of horn players
in Britain ?) The strings are superb too, under
the composer. But the hypnotic fire of Mr.
Pears' original performance, a tour de force
if there ever was one, is now reduced a lot
in temperature; the sound is older and thinner, the breath control less good, the drama
watered down, even though the musical understanding is still there.
Nevertheless, most of the emotional magic
of the music remains. Not many tenors, youthful or otherwise, can match Mr. Pears' sympathy for this music that was composed for
him. (But if you know where there's a copy
of the 78 rpm album, just try that.)
The Young Person's Guide, here in its non spoken version, is just one more of dozens of
recordings through this, to be sure, is under
the composer's own direction. A good piece
to have around your collection. It moves right
along at a brisk tempo, this time. I think
maybe the composer is a bit tired of it. Like
Rachmaninoff and the Prelude in C Sharp
Minor, or Sebelius and "Finlandia."
Palestrina: Two Masses, "Sine Nomine"
and "Ecce Ego Johannes." Choir of the
Carmelite Priory in London, John McCarthy.
L'Oiseau -Lyre SOL 269 stereo
Palestrina's music often has an almost too
"white" sound for our addicted modern ears ;
these two Masses are a good antidote, since
they are well contrasted and quite differently
colored. One, the "Sine Nomine" (it isn't
actually nameless-the music is based on a
popular tune which, as we would say, "shall
be nameless") is a dark, shadowed work,
modally in the minor, rather subdued for the
most part and, for Palestrina, somewhat "antique" in sound. Interesting. The other, "Ecce
Ego Johannes ( "It's me-John !") is all the
opposite, cast in an opulent six -part G- majorwith- lowered -seventh, a sound that is also
gloriously effective in the similar motet "Assumpta est Maria" and the Mass derived from
it.
As the Italians manage to make Palestrina
sound vaguely like Verdi, so the British convert him into a good Elizabethan. No matter ;
for the British -type choir, complete with hooting boy trebles and solemnly screetching countertenors, can bring out the musical sense as
well as any type, even if it does suggest
something out of Westminster Abbey or Saint
Paul's Cathedral.
Gregorian Chants. Choir of the Vienna
Hofburgkapelle, Schabasser. Booklet by
R. D. Darrell.
Vox SDLBX 5206 (3) stereo
Ambrosian Chants. Choir of the Polifonica ambrosiana, Biella. Booklet by Mons.
E. M. Caglio.
Vox DLBX 207 Mono only
There is only one way to tackle Gregorian
(or Ambrosian) chant -that is to tackle it in
bulk. If you can call a mere six LP sides
"in bulk."
Gregorian is the mother -chant of all Western music, born with Christianity and the
Catholic Church, brought to refinement in the
earliest Middle Ages and written down in the
notation that developed into our notation.
It became debased and run -down after the
Renaissance, but the tradition wasn't lost
(and the notes were still in print and in
manuscript) ; the present century has seen
the whole corpus of this splendid world of
music revived, in many areas of the Western
world. Ambrosian chant, an enormous body
of music in itself, is merely a side -shoot in
the immense living structure, though once
(the Fourth century) it was for awhile a
major branch.
To sing all the Gregorian (and Ambrosian)
music straight through just once might well
take a dozen years. It's that extensive. Six
LPs, though, do give us a brief taste of
and the two booklets that accompany these
heroic albums are absolutely splendid.
The Austrians' Gregorian album makes a
lovely addition to the already extensive Gregorian recorded literature. Their singing is
closer, more personal, warmer than, say, the
austerely beautiful French Solemnes singing
(where Gregorian was first restored). Their
earnestness is everywhere apparent, their
musicality is first rate and sensitive. R. D.
Darrell's booklet is the best "layman's" account of the whole business I have ever run
into and though complex, necessarily, will
make a lot of listeners happy.
The Ambrosian music is sung by a Milanese
choir, including women and (I think) children
-that was the Milan tradition, established by
Ambrose in the Fourth Century and zealously
maintained ever since. The singing is not as
pure as the Austrian ; there is inevitably a
faint touch of "La Scala" and Caruso in the
sound, the pitch is less accurate and the
ensemble is not as good as the Viennese, with
more wobbles, slides and individual voices
standing out. Not bad, even so. The immense
booklet (both books have complete texts and
translations) has a certain air of special
pleading ; for Ambrosian chant is not, alas.
the "official" church chant though recognized
and accepted. Still, a very interesting historical survey and account of the Ambrosian
style.
it-
Bach: Cantata No. 80, "Ein Feste Burg ";
Motet "Jesu meine Freude." (a) Soloists,
Figuralchor of Stuttgart Mem. Church,
Wurttenburg Ch. Orch., Rilling. (b) Stuttgart Hymnuschorknaben, Stuttgart Bach
Orch., Gerhard.
Vox STLP 514.150 stereo
Time we've finished listing all these Stuttgart performers, there's hardly room left for
a review. They're good performers, though.
The great "Ein Feste Burg," with the familiar hymn tune on which it is based ringing
out above the immense musical complexities
of its fabric, is given an impetuous, earnest,
sincere performance, that is also very modern
in its exactitude of proper forces and the
currently -proper fast, no-nonsense tempi,
without sentimental romanticisms, the chorale sung at speed and minus pauses at the
ends of the phrases. A first -rate performance,
even if the solos, as always, are swept along
by the great river of music with hardly a
chance to get a breath -but that's Bach's
fault, not the performers'. The river itself
is what counts, and it's enormously effective
here.
"Jesu meine Freude" at last is sung correctly and easily in the way it was intended,
the voice parts doubled throughout by instrumental support. For long, these Bach motets
were mistakenly sung as a cappella works,
i.e., for voices alone. The job was almost
superhuman, what with the unremitting
struggle to stay on pitch and to delineate the
complex harmonies without the help of an instrumental bass. Few performances managed
to make much sense of the music. Now, these
excellent little boys sing the thing joyously,
easily, bouyed up by the instrumental aid,
and the piece comes through, with all its
density of expression, as a tremendously effective Bach work. This is the way Bach himself
meant it.
Trio Flauto Dolce (Music of the Renaissance and Baroque). Robert White, tenor;
Martha Bixler, Eric Leber, Morris Newman.
Flauto Dolce TFD 1 (stereo)
This small group is hunching its own
record, one of those earnest projects that still,
today, persist in competition with the slick
releases from the big outfits. More power to
them The music is one of those now- common
"old music" programs, ranging through vocal
works and instrumental combos of recorders,
!
harpsichord, bassoon, featuring in a good
many pieces the voice of Robert White, relieved from monotony by all -instrumental interludes. Side 1 gives us music from the court
of old Henry VIII, including a work by His
Royal Self, who was a good composer between
wives ; there follows some post- Elizabethanperiod, Jacobean music -equally interesting.
A big jump takes us into the Baroque with
Schutz, in German, and on Side 2 similarly
to France, with Campra and Boismortier. The
in- between period is filled out via a group of
Elizabethan Ayres.
Mr. White's voice is a bit hard to take at
times ; he is a very modern tenor, taut and
dry in tone with a tight wobble, and his pitch sense is not very discerning. He seems best in
the Elizabethan music, where he somehow
relaxes and opens out. The recorders, harpsichord and bassoon twitter and gurgle away
most musically in many combinations. They're
fine.
Acoustics, in a smallish room, are dead for
today's taste though the music is made clear
in detail. Sounds amateurish- though this
is strictly a matter of aesthetic preference,
of course. Odd-the record doesn't say if it's
stereo (though "two mikes" were used plus
a "compatible" groove). All I know is it
sounded best on stereo ; there were cancellations and a thinner effect on mono. So make
it stereo, then.
Handel: Israel in Egypt. Adele Addison,
Florence Kopleff, John McCollum, Louise
Natale; Musica Aeterna Orch. and
Chorus, Waldman.
Decca DXSA 7178 (2) stereo
The great Handel oratorios, "Messiah" in
particular, have always been the property of
the big chorus, amateur and semi -amateur.
Here we have a modern professional performance using pros in the small chorus (a
fraction of the old taken-for -granted size)
as well as pros for the solos. The effect is
somewhat un- Handelian by familiar standards ; the big, rich, wobbly modern choral
voices, all trained to the gills, are not what
the music needs in tonal quality, making it
sound physically a bit on the "Il Trovatore"
side, or maybe "Die Meistersinger."
Nevertheless, the ensemble is led by a
hardened old pro from Europe who has a
heart of gold-and knows how to get over
the essential drama of this most exciting of
all the Handel oratorios, as well as the musical sense in detail. The first part, detailing
the famous plagues, is imaginative without
being a bit corny (the jumping frogs, the
buzzing flies, are perfect) and the second
half, devoted to magnificent and high -minded
rejoicing in sacred terms, has the proper
broadness of scope. The soloists, modern of
course, nevertheless are intelligent and awake
in their relatively small role (the double
chorus does almost all the work). And the
instrumentation is "authentic," with both an
old -type organ and a harpsichord for the
continuo.
The Decca recording is not entirely a happy
job ; in their efforts to get the double chorus
effect down clearly the engineers have somehow forced everything into two-sideness, with
a lack of good middle ensemble. And the "portative" organ (portative like, say, ten Ampex
3508) is too close and squealy. Chorus and
solos are fine.
The recording makes an interesting comparison with (1) the Vox version (Dessoff
Choirs), equally dramatic though with the traditional large chorus and orchestra, and (2)
the incredibly soggy, undramatic, monumental, elephantine British recording from
Angel, sung by the enormous Huddersfield
chorus, which must have 950 singers at least.
This Musica Acterna chorus has maybe 30.
Contemporary Choral Works (Kay, Rorem, Flanagan, Wuorinen). Kings Chapel
Choir of Boston, Cambridge Festival
Strings, Pinkham.
Cambridge CRS 1416 stereo
I've never been very enthusiastic about the
foundation -commissioned modern work, even
if composers must live somehow. It's against
AUDIO
52
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
human nature. This somewhat mixed program
is the direct result of a Ford grant to Mr.
Pinkham, and it's just what I would have
guessed it might be-a mixture of styles and
manners and techniques without the slightest
relevance, each piece to the next, nor any
reason (that I can hear) for being offered as
one unit on an LP record. Except that the
grant paid for all the music.
There's a mild, quite sweet pair of Psalms
and a Proverb by Ned Rorem, then a whopper
of a serial piece, by Wuorinen, dreadfully
solemn as I hear it, all about Jonah being
vomited up out of the whale's insides. (It may
be "simplified" as the composer says, but it
sure isn't simple.) Then there's a big three part Triptych by Ulysses Bay that grew out
of its third part, an Alleluia, skillfully written for voices, and some Chapters from
Ecclesiastes by Rorem's cohort, William Flanagan, these two being of a not-very -dissonant
persuasion. It all hangs together barely-by
virtue of the all- sacred texts, the common
chorus and the capable solo voices upon which
all but Mr. Rorem thought it wise to count
for their more difficult ideas.
'Course I might be wrong, and there's
nothing inherently unfair about being complex and dissonant. Or writing in your own
style regardless of the next man. But today
just isn't a very good time for choral music,
as Mr. Pinkham's Ford-grant productions
show only too well. Composers' ideas are now
technically as precise as our engineers' in
other areas, geared to the extreme precision
of modern musical instruments. To expect
these men to write music for chorus is like
trying to build a Ford V -8 with hacksaw,
hammer and hand hoist, plus maybe a T-
citizen is sprouting cultural wings, and
the trend can only go one way, toward
more and more of this world's good
things.
This cultural revolution is FM's opportunity. It also represents an opportunity and a challenge for the leaders
Æ
of our communications industry.
IF YOU ARE
MOVING
Please notify our Circulation Department at least 5 weeks in advance. The Post Office
does not forward magazines sent to wrong destination unless you pay additional postage, and we can NOT duplicate copies sent to you once. To save yourself, us, and -the
Post Office a headache, won't you please cooperate? When notifying us, please give
your old address and your new address.
Circulation Department
RADIO MAGAZINES, INC.
P.O. Box 629, Mineola, N. Y.
PNE-,
A 10- MINUTE COURSE ON MICROPHONES TO
ee'AL
EXPP
SUCCESS STORY
square and a ruler.
Mozart After Hours. Maureen Forrester,
vocalist; Vienna Akademie Choir, Members Vienna State Opera Orch., Jazz
Rhythm Group, Kingsley.
Vanguard VDS 79165 stereo.
This studied travesty of good Mozart seems
to have been improvised, ever so artlessly,
by the batch of distinguished performers you
will note above during the off-hours of their
Vanguard sessions with Bach, Haydn, et al.
I say travesty deliberately -for compared to
the work of the Swingle Singers (whose
Mozart recording is due shortly), these items
are pretty painful. That is, if you know the
Mozart originals. Not very improvisatory
either ; I'd call them full -fledged commercial
arrangements. But what really is sad is the
chopped up Mozart sense, the half -baked
harmony, following Mozart just far enough
to matter, then fobbing off with commercial type clichés, dropping the little composer in
midstream each time. Nope, I found it awful,
as well as very dull.
I'd say our classical musicians had better
stop showing themselves up in this fashion.
They'll do better where they belong, following
the notes. Mozart's notes.
FM
(from page 40)
in the history of the human race. A large
proportion of U.S. citizens are better
schooled, better informed and more alert
than any group in human history.
For the marketer this well -heeled
group of educated elite represents a
mass market of enormous proportions.
There are 16 million "executives" and
their families in the U.S. These males
represent 25 per cent of the male working force and they are the people whose
tastes and education have already made
culture a more popular pastime than
sports. They partly account for America's current cultural binge. The U.S.
Why the new 8000
is the most demanded
microphone
(of its kind!)
New University 8000: $29.95.
With slide switch (the 8100): $31.50.
Model DS -10 Desk Stand: $6.95.
Tape Recording. Cardioid mikes are essential
for quality recordings. They pick up cnly the
performer over a wide frontal area. They prevent the output of speakers from affec :ing the
mike, thus eliminating feedback squeal, and
permit recordists to work from far or near. For
stereo, only cardioids can assure proper balworld's only five -year microphone
ance, if both are matched. University quality
warranty!
control makes any two 8000's absolutely
The new University 8000 is a "first"
identical "twins" to assure full stereo effect.
and "only." For those who like to be exclusive, that's one reason for buying it. The
Realism. The new 8000 offers wide -band
important reasons may be found in the follow- response, extremely uniform to eliminate
ing microphone buyers' guide!
sibilants (hissing S's), bass boom and tinny
There Are Cardioids...and Cardioids. All car - treble. Its reproduction quality is virtually indioids are essentially "deaf" to sounds origi- distinguishable from the live performance. The
nating from the rear. They're invaluable for 8000 has variable impedance
250 to
eliminating background sounds, for use in noisy 20,000 ohms, and comes with a 15 -foot cable.
and reverberant areas, for reducing feedback
For complete specifications, ask your dealer
and for permitting a higher level of sound reinfor literature or write LTV /University, 9500 W.
forcement before feedback would normally Reno, Oklahoma City, Oklahoma Desk R-25M
occur. BUT -not every cardioid uses rugged
dynamic generating elements. There are crystal
cardioids which offer high sensitivity and output. But their response is limited; deterioration
is rapid due to heat, humidity, rough handling.
A DIVISION OF LING.TEMCO.VOUGHT- INC.
The University 8000
cardioid dynamic
virtually indestructible.
9500 West Reno, Oklahoma City, Okla.
It's a cardioid. It's dynamic. It's
shock -mounted. It offers variable
impedance and uniform wide -range
response. It's designed and made by
LTV /University and it's less than
$50.00. Less than any other cardioid!
It's only $29.95. And it's sold with the
-
,
s
-a
-is
UNIVERSITY®
Circle 126 on Reader Service Card
AUDIO
FEBRUARY, 1965
53
www.americanradiohistory.com
AmericanRadioHistory.Com
NEW PRODUCTS
Lightweight Stereo Earphones. AKG
for a new high
fidelity stereo earphone that weighs all of
3.8 oz. Frequency response of 20 to more
than 25 kc is claimed. Also claimed, is full
bass response without requiring a tight
air seal. The result, combined with the
ultra-light- weight, is a significant reduction in the usual fatigue experienced from
K -50 is the designation
protracted use of earphones. High efficiency and very low distortion are also
claimed. Specifications call for 0.156 milli watts for a sound pressure of 95 db. At
the same time the devices will handle 90
mllliwatts per unit with distortion from
20-25 kc under 3 per cent. The phones are
available in impedances of 400 ohms per
unit. Also available are 200 and 75 ohm
units. Price for the AKG K -50 with 5 feet
of four -wire cable, is $22.50.
Circle 200
8 Track Reads. Nortronics announces a
new 8 -track stereo tape head for 14-in.
tape. The Model B2L stereo head offers
twice as much playing time as the standard 4 -track systems. A fine, 100-microinch gap assures excellent performance
at 3% ips. The head is mechanically indexed to four discrete positions to provide
four stereo or eight mono channels. The
heads will be available in either solid or
laminated core versions. The B2L head has
a hyperbolic, all -metal face with special,
close fitting mu -metal shielding to eliminate external noise. In addition to its play playback capability, Model B2L can be
used as a record /playback head and is
available in various impedances to accommodate all types of circuitry.
Circle 201
Dust Cover. Owners of Dual record players can now purchase a complete base /dust
cover of attractive styling and proportions.
This DCB -1 enclosure has side panels of
oiled -walnut to match the base, with rigid
smoke -tinted plexiglass on the other surfaces. The cover can be lifted off the base
at any time, or left in raised position. Price
of the complete unit is $29.50. Circle 202
New Stereo Receiver. Allied Radio has
just announced a new stereo multiplex
FM -AM tuner -amplifier. Knight Model
KN -370 combines on a single compact
chassis a 35- watt -per -channel stereo amplifier, individual FM and AM tuning sections, special multiplex circuitry that
automatically switches to stereo, and dual
preamplifiers. FM sensitivity is given as
2.5 µv for 20 -db quieting; i.f. bandwidth is
300 kc; amplifier power is 70 watts IHF, 32
watts per channel, steady- state; frequency
response is 20 -20kc t ldb at full rated
power. THD at full power is less than 0.6
per cent with hum and noise down - 60 db
on phono and - 75 db on aux or tuner. Full
program source control is offered. Outputs
include 4, 8 or 16 ohms for speakers, hi -Z
combined channel output, and low -Z front
panel switched earphone connections. Price
of the KN -370 is $279.95 less case. A walnut case is $23.95 and a brown metal enclosure is $12.95.
Circle 203
New Tape Line. Superscope, American
distributors of the Sony tape recorder lines
have begun shipments of a new polyester based tape. Sony PR -150 tape is wound on
computer typereels for easy threading.
Distinctive markings have been designed
on each side of the reel. Side one is
marked in gold; side two in silver. The
tape leader is green and the tail is red.
Owners of Sony tape recorders can receive
upon application, discount books for the
new tape. New recorders will have these
books enclosed. PR -150 is the only tape
announced thus far. It is a 1 -mil polyester
offering on a standard 7 -in. reel, with 1800
feet of tape.
Circle 204
Reversible Stereo Recorder. Full automation has been built into the new Concord model 994 stereo tape recorder. This
model will play and record four -track
stereo in either direction, reversing direction at the end of a, tape automatically. A
built -in "Electronic Memory" enables the
54
user to program the recorder for such
manual or automatic operations as: single
play, automatic reverse, and continuous
play or record. The 994 can be programmed
to play for any length of time, half-hour,
hour, or all day, as desired. Three -speed
operation (7%, 3% and 1% ips). Two erase
and two record /playback heads operate in
either direction of tape travel. Frequency
response at the 7% -ips speed is 40-16,000
cps t 2db. Flutter and wow at this speed is
less than 0.15 per cent rms. Solid -state
electronics. Two VU meters are used for
level indicators. This model is a complete
recorder with built in dual 7.5 -watt amplifiers. Built in 8 -ohm speakers. Weight is 44
lbs. and dimensions are 151" wxll %" hx
17" d. The 994 will also be available as a
deck only -designated the model 990. The
994 complete unit is $339.50.
Circle 205
New Cartridge System. Euphonies Corporation has just released a new phono
transducer that operates on the principle
of an external current modulator, rather
than a generator itself. The results, it is
claimed, are substantial reduction in tip
mass concurrent with high output. The
system uses silicon elements smaller in
volume than the diamond stylus tip itself.
It is being promoted as a perfect match
for the low impedance inputs of transistor
amplifiers. An external power source is
required to supply current for the silicon
elements to modulate. Each of the silicon
elements requires 10 milliamps d.c. for a
power of 0.1 watts. Under these conditions,
output is about 25 my with a source impedance of only 600 ohms. Frequency response is claimed from d.c. to beyond 30
kc. Separation is quoted in excess of 25 db.
A bi- radial diamond stylus 0.9 x 0.2 mils, is
utilized. Outputs of the system are RIAA
flat for ceramic inputs and equalized for
magnetic preamps. The cartridge system
will be available in an integrated low -mass
arm balanced in all coordinates. Compliance of this integrated system is 30 x 10 -e
am /dyne.
Circle 206
Revised Speaker Systems. New versions
of old favorites have just been announced
by AR. The AR -2 and AR -2a speaker systems have their tweeter and mid -range, respectively, replaced. What was formerly a
two- speaker array for top end in the AR -2
(mid -range on the AR -2a) is now a single
3 % -in.
broad -dispersion cone tweeter,
heavily damped by Fiberglas on both sides
of its diaphragm. The main improvement
is in dispersion, although there is also
some improvement in smoothness and, for
the AR-2, in high- frequency range. These
new speakers are designated the AR -2= and
the AR -2a.. For identification they will be
supplied with a new grille cloth. They are
stated to be completely compatible with
the older versions in stereo use, but the
older units will still be available to those
that wish exact matching. In addition
owners of older units can have them converted to the new driver with the purchase
of a $15 kit from AR dealers or directly
from the company. The prices of the new
speakers remain unchanged from their
progenitors. They are $89 to $102 for the
AR -2. and $109 to $128 for the AR-2a..
Prices depend on wood and finish.
Circle 207
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
1
want to stop throwing money away. Send me all the literature on McIntosh products.
McIntosh Lab., Inc., 6 Chambers St., Binghamton, N.Y.
please check
tube stereo preamp
C 24 solid state preamp
MR 71 fm stereo tuner
MR 67 fm stereo tuner
C 22
MX 110
NAME
MC 225 stereo power amp
MC 240 stereo power amp
MC 275 stereo power amp
MA 230 stereo amp /preamp
STREET
CITY
STATE
stereo tuner /preamp
IMO
.
I
Q
Nf.N
ti
I
,
Tired of throwing money
away?
Consider this
All tuners, amplifiers, preamplifiers sound good when you
first get them. ONLY McIntosh units continue to sound good
year after year, after year, after year, after year, etc.
Now the best stereo electronics can be yours. Why settle for
second best? McIntosh systems start as low as
and less than $19.00 a month.*
*from most dealers
LABORATORY INC.
6
Chambers St., Binghamton, N.Y.
Circle 127 on Reader Service Card
AUDIO
$59.70 down
FEBRUARY, 1965
www.americanradiohistory.com
AmericanRadioHistory.Com
55
NEW LITERATURE
Lamp Guide. Tung -Sol has announced
the availability of a new 24 -page guide
covering their full range of miniature, subminiature, and sealed-beam lamps. Designated form A -21, this guide illustrates all
elements of the design and configuration
of the Tung -Sol product line so as to aid
in the engineering and design of equipment for which the lamps are applicable.
The guide also supplies a complete listing
of electrical and physical characteristics
of the several hundred lamps in the Tung Sol line.
Circle 209
8eathkit Catalog. Heath has just announced the 1965 edition of their annual
electronic kits catalog. This year there are
over 250 products listed. The Heath product line is designed to appeal to a wide
range of electronic interests. Toward that
end, the catalog shows stereo components,
electronic organs, both a color and b & w
TV receiver, a photo enlarging computer,
recording electrometer equipment, a line
of SB amateur transmitters and kits, CB
equipment, electronic test gear-and then
some. Every kit is listed in this free new
108 -page color offering from Heath.
Circle 210
RCA 'Transistor Manual.' A second edition of the "RCA Transistor Manual" featuring technical data on more than 600
semiconductor devices and 45 "easy -tobuild" circuits is off press. This latest
printing of the manual (SC11) is bigger
and better than its successful first edition,
and has been enlarged to 384 data -packed
pages covering all types of semiconductor
devices. To the designer, student, hobbyist, or anyone interested in the dynamic
subject of semiconductor devices, the new
edition offers more data, more easy -to -read
basic theory and more do-it- yourself circuits. Some of the typical circuits included
in the popular manual are: two portable
radio receivers, two automobile radio receivers and two automobile ignition circuits (for both 6- and 12 -volt systems), a
three -band radio receiver, earphone and
phonograph amplifiers, two stereo amplifiers, citizens -band transceiver and transmitter, a silicon-controlled rectifier light dimmer circuit, and many other circuits.
More than 80 pages of revised, descriptive
text in the SC -11 manual are devoted to
bringing the reader up -to-date on the
latest semiconductor- device technology
and applications. Copies of the new RCA
Transistor Manual are available through
local RCA distributors or from Commercial
Engineering, RCA Electronic Components
and Devices, Harrison, N. J. Price of the
SC-11 is $1.50.
COVER STORY
This component system sounds off in
the home of George Colton who lives in
the Tomahawk Hills section of Kansas
City, Kansas. The main control panel
is slanted at an angle of 12 -deg. for
ease of operation. Incorporated in this
panel are auxiliary speaker switches and
a jack for stereo phones. Both record
and tape storage is provided, as well as
an open compartment for a portable TV
set. Components used are a McIntosh
C11 preamp, McIntosh 240 power amplifier, Fisher FM -1000 tuner, Bogen
B61 turntable with a Shure M7D cartridge containing the N21 stylus, and a
Sony 500 tape recorder.
The layout was designed by Fred
Hulen of Contempera Stereo in Kansas
City. He noted that it is particularly intended for people with limited space
availability, such as apartment dwellers.
SHUNTED DOTS
(from page 21)
and some of these will prove useful.
Computation of the simpler cases will
not prove too onerous a task, particularly if the simplified "relativistic" notation here employed is used. Computation
of the characteristics of the more complex cases may be extremely involved;
and there are a few that, like lens computations, must still be worked out by
successive approximations.
JE
1 Pender,
Harold, and Warren, S. R.
"Electric Circuits and Fields," McGraw Hill, 1943.
2 Guillemin, E. A. "Introductory Circuit
Theory," Wiley, 1953.
"I'M RATHER SENTIMENTAL
ABOUT THIS NEUMANN U- 47..."
...says C. Robert Fine, President of one of the country's
top film and disk studios, Fine Recording Inc., New York
City. "...It's been a smart investment ever since made
one of the first Mercury stereo recordings back in 1949.
It's still in service today as good as the day it was
made." (Incidentally, if he ever needs service on this
famous but now retired model, or any other of his
I
numerous NEUMANN condenser microphones, we'll
always have parts available.)
You too will make such statements sixteen years from
now if you invest today in one of the many current
NEUMANN
condenser microphones such as the
or the newly introduced
U -67
U -64.
NEUMANN
has devoted more than 30 years to the
manufacture of condenser microphones exclusively.
GOTHAM will be pleased to send you detailed information on the particular unit best suited to your needs.
OTHAM
AUDIO CORPORATION
2 WEST
46 STREET, NEW YORK, N.Y., 10036
212 -00 -5 -4111
1 -Mar
Electronics Ltd., P.O. Box 158. Don Mills, Ontario
In Canada:
Circle 128 on Reader Service Card
56
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
SOUND REINFORCEMENT
(from page 26)
before feedback." In practice, the freWe have frequently heard sound sysquency shifter was utilized for only one tem contractors rationalizing poor reweak -voiced speaker. It was not neces- sults in temporary sound systems on the
sary for amplification of organ and basis of inadequate time to plan an engipiano. Also, we found it inadvisable to neered installation. The two sound sysuse the shifter when Billy Graham or tems employed for the Billy Graham
anyone else with an extremely wide Greater Boston Crusade indicate that fine
dynamic range spoke, since the dynamic results are possible even in temporary inrange of the remainder of the sound stallations. The equipment and over-all
system exceeded that of either com- system designs used in the systems demercially available frequency shifter.
scribed are not, of course, applicable to
Without the frequency shifter feed- every situation; but the articles of recent
back stabilizer, sound energy directéd years in this magazine and such technical
from the choir distributed loudspeaker journals as the IRE -IEEE -PGA and the
system picked up by the microphones ac- Journal of the Audio Engineering Sotually determined the feedback point of ciety have provided a wealth of informathe complete system.
tion that can be applied to sound system
Press comments on the sound system design and installation problems encounmay be summed up by one Boston Globe tered in such situations that have been
report, "Clearest sound ever heard in discussed here.
the Garden."
It goes without saying that the fine
Some modifications to the temporary results achieved in these two systems
system would be required for perma- would not have been possible without the
nent use in the Garden. Loudspeakers complete cooperation of many particisuspended on cables would have to be pants : The staff of the Billy Graham
relocated to under- balcony soffits, and Greater Boston Crusade; the installing
horns would have to be added to the contractor, Lake Systems Corporation
central loudspeaker cluster to insure of Watertown, Massachusetts; the varicomplete 360 degrees of coverage, when ous manufacturers of the equipment emrequired. Also, experience suggests more ployed in these systems ;12 and the staff
stages of time delay in the under-bal- of the Boston Garden; and, of course,
cony distributed system as desirable to James Galvin, the operator of the Garfurther improve naturalness and intel- den system.
Æ
ligibility; two delays were sufficient to
insure sufficient intelligibility, but the
12 Altec Lansing Corporation, Anaheim,
localization of the under -balcony loud- California;
Audio Electronic Products, Despeakers was obvious in some of the side troit, Michigan; Audio Instrument Co.,
locations.
u M.
R. Schroeder, "Improvement of
Acoustic-Feedback Stability by Frequency
Shifting," JASA, vol. 36, No. 9, September 1964, pp. 17-24.
You can't
tell the
difference
between the
Oki 555
and any other
stereo tape
recorder
until:
lift
You
it. It's the lightest
portable stereo tape system in
the world. Under 25 lbs.
You check for tubes. It has
none. It's solid state (all transistors ... 27 of them).
You hear it. It has 2 unique
two -way speaker systems for
cleaner stereo sound
reproduction. (4 speakers.)
You check its dependability.
It's guaranteed for 1 full year.t
New York, New York; White -Austin Company, Austin, Texas; (System design was
accomplished by Professor James Bruce of
M.I.T. and Douglas Steele, Wilfred Malmlund, and the author, the latter three of
BEN.)
LETTERS
(from page 6)
(ASCAP), cannot assume the responsi- nor infringe on legal rights which a
bility of legally issuing a blanket license copyright might guarantee. Currently,
to make non -commercial tape recordings the unresolved question is an unmitigated
of copyrighted material and perform- nuisance and, as such, will remain so
ances. The copyright laws in the U.S.A. until remedies are forthcoming. Obviare vague and loosely worded in this re- ously, if some form of blanket license
spect and are not in accord with interna- could be legally granted, through the
tional coypright conventions prevailing payment of a stipend one -time fee, or
in Europe and particularly in England, membership in a record club, and so on,
where the question is a bit "sticky".
every fairminded tape recording fan
The Music Publishers Protective As- would be relieved and the controversy
sociation takes a different view, claiming adjusted.
the law protects them and on this basis
Could it be possible that the Music
may or may not accept payment or roy- Publishers Protective Association in New
alties permitting the use of copyrighted York City may have some views on the
material.
matter, pending a revision of the U.S.
The question naturally arises as to who copyright laws, that may be a reasonable
may have a case and to what extent en- guide to the solution ?
forcement or licensing may be pursued.
FREDERICK C. BERLINGEN
I, like most recorder hobbyists, am not
1649 North Mozart Street
inclined to disrespect the copyright laws
Chicago 47, Illinois
And its price is less than you'd expect to pay. $349.95 *.
Oki has a fine choice of other solid
state tape recorders, starting at
$129.95 *. See and hear them now at
your Oki dealer.
*manufacturer's suggested list price
tone year parts, 6 months labor
AU 265
Chancellor Electronics, Inc.,
457 Chancellor Ave., Newark, New Jersey
Name
Address
City
I
I
State
Zip
I
CIRCLE 129
AUDIO
FEBRUARY, 1965
57
www.americanradiohistory.com
AmericanRadioHistory.Com
AUDIOCLINIC
(from page 4)
channels. Therefore, the channels are not
balanced. A sensitive meter can be used
to obtain rather precise balance.
However, this arrangement cannot be
used for "ping pong" records in which
there are times when only one channel is
operating. Offhand I see no way for you
to balance such records except aurally, at
least when this latter scheme is used. The
meter might well be overloaded.
Remember that I suggested the use of
a sensitive meter. This means that the
meter can be readily damaged by overload. Therefore, when beginning the
balancing procedure, start with the signal level down. If the meter swings above
zero, readjust the balance control till it
reaches the zero position again. Then
increase the volume and again adjust the
balance control if necessary.
Of course, a bridge rectifier must be
used at the amplifier "hot" leads in order
to provide the d.c. needed to operate the
meter.
The third approach makes use of the
zero center feature of your meter. It
might be possible for you to work out a
circuit in which there are two rectifiers,
one for each channel. The rectifiers must
be a matched set so that each channel
will provide equal output when the system is balanced. The rectifier for the left
channel can be made to rectify and give
you filtered, negative voltage and the
right channel can be setup to give you filtered, positive voltage. The time constants of the rectifier and filter circuits
should be so chosen as to give you good
meter damping, but not too much which
would mask program changes. Start with
1/2
12Ax7
M
o
250 milliseconds.
You may find it necessary to shunt the
meter with diodes wired in parallel, with
the anode of one connected to the cathode
of the other.
Do not confuse these latter rectifiers
with those used to obtain the d.c. required to move the pointer of your instrument. These latter devices are chosen
to allow full scale meter reading without
significant conduction, but must conduct
heavily very shortly after the full -scale
reading has been passed.
The final phase of your letter concerns
obtaining balanced signals from the output of your preamplifier. This is most
easily accomplished by means of a VU
meter and the auxiliary amplifier circuit
shown in Fig. 1.
Power for the unit may be obtained
directly from the preamplifier or may be
obtained by means of a separate power
supply. 250 volts d.c. at 20 ma is sufficient for B voltage. Filament requirements are 6.3 volts at 0.3 amp or 12.6
volts at 0.15 amp.
After the unit has been constructed,
the potentiometers should be adjusted to
provide equal meter scale indication on
each channel for a given input signal
voltage. The amount of voltage used as
your zero reference will depend upon
the nature of your requirements.
I recommend this circuit to be used in
conjunction with one of the three circuits
discussed earlier. You will then be in a
position to monitor your power amplifier
output and your preamplifier output
simultaneously. If you wish to use the
great sound
a
141/2
that's about the size of it.
The new Sonotone Sonomaster® is really compact
. in fact, it's downright small (141/2x101/2x71/4").
But don't let this fool you, because it requires only
modest power to provide "big sound" performance.
The power handling capacity is 40 watts average
(80 watts peak) Two superb speakers, combined
with an integrated crossover network, give you full
.
SONOTONE
audio products
rich audio coverage. Handsome to behold, too-a
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oil- finished walnut cabinet. It's the ideal complement in your stereo system. Less than $90 a pair
($44.50 each). Also hear the velocitone Mark IV
stereo cartridge (less than $25), at your hi -fi dealer.
For.descriptive brochure SAH -90 write.
Sonotone Corp., Electronic Applications Div., Elmsford, N. Y.
Circle 130 on Reader Service Card
AUDIO
58
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
same meter to monitor both amplifier
output and preamplifier output levels,
appropriate switching and calibration
networks must be provided. If you use
the third scheme proposed here, a somewhat more involved circuit will be required.
This discussion should provide you
with sufficient information to enable you
to carry out additional experiments.
Muting Stereo Systems
Q. What is a simple way of muting a
stereo audio system without turning down
or in any way touching the volume control of the preamplifier, as when changa record or tape.
I would prefer some pushbutton
switching method that would not entail
getting into the internal wiring of the
preamplifier if possible.
Another restriction here is that transient noises, such as "pops" are not heard
when switching. Henry T. Sugiura,
Phoenixville, Pennsylvania.
A. The way I go about muting the
audio during the time I change discs or
tapes is merely to use the selector switch.
I move it to a position which is not being
used, say the tuner position. When the
tape has been started or the tone arm
placed in the lead groove of a disc, I
reset the selector switch to the appropriate input and I hear the sound with
proper level, free from hum or the thump
of the stylus coining to rest on the surface of a disc.
If your selector switch is "clean" insofar as transient clicks are concerned,
you will not hear any clicks during the
switching process. If you do have some
transient clicks, they often can be removed by placing 5-megohm resistors at
the outputs of all signal sources. When
these sources are switched in, their capacitors will already be charged because of
the ground path through the resistor, and
no "pop" should be heard.
If transient clicks are heard when an
early stage of a preamplifier is switched
into the circuit, the same treatment can
be applied. The switch side of the coupling capacitor is the point at which the
resistor is connected, with the other end
of the resistor grounded.
Note
When writing to me, please address
your letters to the address shown in this
column rather than to Aunio Magazine.
Sending letters to the magazine only
slows their delivery.
On the plus side, thank you for sending the stamped, self addressed envelopes
with your letters. It makes answering
you proceed much faster than otherwise
would be the case. However, many of
your envelopes bear your own return address. Actually they should contain my
return address because I am the one
ACOUSTICAL REARGUARD
Range: 30- 18,000 cps (cardioid)
30-30,000 cps (omni -directional)
Response: ± 2.5 db over entire range
Dimensions: 3/4" Dia. x 4"
Data sheet available on request
Response: `= 3db over entire range
Dimensions: 55/a" x 21/2" x 2'/a"
Data sheet available on request
Insensitive to sound reaching this dynamic
microphone from the rear...An exceptionally
pronounced cardioid pattern produces an acoustical shield of approximately 180° that effectively
isolates unwanted sounds originating from noisy
audiences, feed -back or reflection.
AUSTRIA BY AKG GMBH.
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AUDIO
quality condenser microphone for music
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A high
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sending the letters ; if you were sending a letter to me, your return address
would be on the envelope.
As you know, many of the questions I
answer, are tricky and I can guess how
to solve your problems more accurately
only when you provide me with as much
information as you can as to what you
see or hear and as to what steps you took
to correct the condition. I also need to
know what happened to a particular circuit when a corrective step was taken. By
doing this you will help me answer your
letters more quickly and more accurately.
To illustrate what can happen I recently ran into a problem in which I was
told that a certain record changer was
used in a radio and could this changer be
transferred to a component system. I
assumed that this transformation could
be easily accomplished. It turned out,
however, that the record changer motor
was a special unit whose voltage requirements were such that it was used as ballast in a series heater string. When the
questioner connected this motor to the
line, it overheated and almost burned out.
Had I been given all of the facts, model
of radio, and so on, this wouldn't have
happened. Fortunately, the motor did
not burn out, and it was possible to recommend that a resistor be inserted to act
as the heaters and absorb the over-volt-
N. Y.10017
Circle 131 on Reader Service Card
FEBRUARY, 1965
59
SPECIAL ELECTRONIC ORGAN
DYNACO
STEREODYNE
phono cartridge
by B
ti
&0
TONE
SOURCES
(from page 32)
energized by depressing a key, the ham-.
mer strikes the anvil and holds the V out
of contact with the anvil. The chime
tones generated by this striking action
will continue to ring naturally until the
tone dies out, or the coil is de-energized
by releasing the key.
There is one inductive pickup coil for
each bar so that it is possible to play
several or all of the chimes together. Mechanically, the keyboard is usually fastened close to the great manual. The
amplifier is of conventional design.
The Schulmerich ChimeAtron is a genuine musical instrument, the chimes are
of delicate timbre and yet their charac-
one of the truly
musical pickups"
With the exception of loudspeakers, no part of your
music system affects its
quality as much as the choice
of a phonograph cartridge.
Specifications and test reports, while helpful, cannot
substitute for a thorough
listening evaluation in making so crucial a decision.
III
is the
The Stereodyne
latest refinement by E. R.
Madsen of Bang and Olufsen,
who first recognized the importance of standardizing on
a 15° stylus angle. In separate arms, as well as in the
better changers, its clearly
superior sound will be
apparent.
Fig. 8. Tempo wheel disk and rim wheel
drive of Side -Man.
Fig. 9.
Tuned bars and electronics of
Schulmarich ChimeAtron.
Wide, smooth response
Lower distortion
Less crosstalk
Lowest hum (by a mile!)
Replaceable stylus
15° vertical angle
just $19.95
Be sure you listen to
this cartridge at your
audio specialist's showroom
ter can be changed almost completely by
changing the amplified audio output
level. It is rather striking to hear these
chimes at very high audio levels. The attack, the decay and the harmonic content make the Schulmerich sounds pleasant contrasts to the organ sounds. It is
not at all surprising to note that many
professional organists include chimes for
a cadenza, a refrain or as an interesting
solo voice.
The ChimeAtron that is available from
Schulmerich or their dealers includes a
small oval speaker. The Schober Organ
Corporation also supplies a Schulmerich
Chime set, but less the speaker.
There are two difficulties associated
with the purchase of the complete package if you already own a hi -fi system,
or an organ with a self -contained audio
system. In both cases, your speaker is
far superior to the oval speaker contained in the Schulmerich. This is not to
be interpreted as a discredit to the integral unit, because the oval speaker is
adequate for the tonal range of the
chime set.
The second problem comes into being
because the integral unit is subject to a
10 per cent excise tax. The Schober
unit is identified as CH -1 and sells for
about $400.00 f.o.b New York, whereas
the Schulmerich with the integral speaker lists for about $475.00 with an additional 10 per cent for the excise tax,
making a total about $522.50.
The three specialized musical instruments that we have just described are
not solo instruments, but tonally they do
provide complementary sounds to the
electronic organ. The controls of each
are such that the organist can easily operate them without difficulty.
TO BE CONTINUED
-ROD
VEE
CORD
ANVIL
HAMMER
GROOVE
EYELET
BRACKET
Fig. 10. Suspension of Schulmerich ChimeAtron.
LOOP
SPRING
DYNACO INC.
3912 POWELTON AVENUE
PHILADELPHIA, PA. 19101
TOP SUSPENSION
LOWER SUSPENSION
CIRCLE 132
60
AUDIO
FEBRUARY, 1965
LOW- FREQUENCY OPERATION
(from page 2')
the change. In the case of power amThe only practical manner to minimize
plifiers where the last one or two stages this is to employ a fully regulated
are of a push -pull configuration, the supply. Further improvement can be had
B+ (or corresponding supply line in a by making the regulated supply "negasolid -state design) has more filtering as tive impedance" (as the load increases
one progresses toward the input of the the output supply voltage also insystem. Thus the time constant of the creases). Supplies of this type are not
supply voltage to individual stages differ easily applied to equipment not intended
greatly with the push -pull stages re- for them. In general a "zero impedance"
ceiving the least filtering or, in reference supply, one where there is no change in
to time, the shortest time constant. In output voltage for any load condition
this manner it is quite easy to observe should provide the best improvement
that a drop or rise in supply voltage for existing units. The effects of supply
would vary the respective supply volt- variation are more apparent at the low
ages of all the individual stages different end of the frequency range although
amounts and at different times. If the similar effects occur elsewhere in the
unit were d.c. coupled such variations frequency range.
would no doubt cause a complete upset of
In some cases of instability the probnormal operating conditions, possibly lem was traced to the supply components
to the extent of blocking the amplifier.
themselves. Lower -priced equipment used
In amplifiers that have a low-frequency fewer filter capacitors each with a higher
bandpass with an over -all time constant capacity. As these capacitors get larger
greater than the time constant of the in capacity, two things occur First the
power supply itself, the above condi- interval leakage currents rise resulting
tion can and does readily occur. Such in a shorter life span ; and second, and
is the case of many "dual channel" ameven more important, they develop larger
plifiers where a signal in one channel amounts of interval inductance. Thus
causes the supply voltages to vary and while the capacitor may provide a low
produce a corresponding signal on the impedance to frequencies at or near the
other even though the second channel is ripple frequencies, it may appear much
not receiving a signal at its input. In higher at the upper frequency limits of
lower-priced single -channel systems this the amplifier. When this happens a consame effect is noticeable by poor recovery dition such as described earlier can and
times from large signal levels. In some does occur. This effect can be minimized
cases it is actually cheaper to make an
somewhat by the addition of a small
additional push -pull stage preceding the ceramic or mica capacitor in parallel
output stages with the idea that an equal with the output electrolytic capacitor.
in-phase signal will be introduced that Usually a value of 0.1 tf is sufficient.
will be canceled out in the output trans- Again a properly designed and built
former.
regulated supply offers a low impedance
Unfortunately this does not materially to all frequencies that are capable of
aid the situation because the output being passed by the amplifier. In fact
stages must now handle the amplified the supply must exhibit a frequency
supply variation in addition to the de- range in excess of the basic amplifier if
sired signal. As a result the power - correct operation is desired.
handling capability of the system is reIt is quite interesting to note that the
duced sometimes by as much as one present method of rating commercial
fourth of its rated output. In amplifiers amplifiers in the hi
-fi category is to
that possess this type of problem the use
replace
the
power
existing
supply with a
of additional filtering or a greater degree
of supply regulation can raise the han- regulated supply and then to establish
dling capabilities up to 100 per cent or their advertising specifications. In most
more. It must be remembered that the cases the existing supply would be inpower responses of the output tubes and capable of providing even a close apassociated components cannot be exceed- proximation of the results obtained in
ed. However, if the associated compo- this manner.
nents can withstand the added currents
In summary the development of amand the chief limitation is now the out- plification equipment has proceeded at
put tubes, they can be replaced with dif- a respectable rate as far as the amplifier
ferent types having a larger handling
assembly itself is concerned. However,
capacity. One must also remember that
as the plate currents rise through the the application of suitable power supsubstitution of different output tubes or plies has not kept up with this degree of
by bias changes, these changes manifest development. The result is the sad fact
themselves as an added load to the power that in many cases the power supply
supply and as such further raise its time is the chief limitation on the quality of
constant.
the complete assembly.
:
DYNACO
introduces THE
stereo recorder for
the connoisseur
If you are one whose stringent
requirements or passion for
perfection has been convinced
of the need to spend at least
$400 for a quality recorder, and
if you have felt that nothing
available to date for less than
$1000 could meet your demands, then give serious consideration to the Dynaco Beocord
2000.
Judge it first on absolute performance -live recording is the
most exacting test for the come
plete recorder -then luxuriate
in its many exclusive features:
stereo mixing inputs with slidetype controls and plug -in multiple
mike conversion
low impedance transformer cou
pled mike input
8 watt amplifiers for PA use, home
music system, monitor speakers, or
low impedance headphones
pushbutton selection of echo,
sound -on- sound, and unique synchro monitoring from half the record head
electronically protected fully transistorized plug-in electronics
3 speeds, 3 heads, 100 KC bias,
synchronous drive
3
Only a comparative evaluation
in use with the finest associated
components will effectively demonstrate the superior performance and unique flexibility of
this superb instrument.
Write for full specifications and ask your
dealer for a demonstration.
DYNACO INC.
3912 Powelton Avenue,
Philadelphia, Pa.
Circle 152 on Reader Service Card
AUDIO
FEBRUARY, 1965
61
www.americanradiohistory.com
AmericanRadioHistory.Com
favorites at the Convention include fiddler
Sonny Miller of Wilmington, Delaware and
George Pegram of Union Grove, North Carolina, whose three -finger banjo picking won
him the 1961 prize. The recordings were made
at the Convention, in a local radio station
and in an open parking lot during the Convention. Under such circumstances, a variety
of background noises could not fail to insinuate themselves onto some of the bands, but
these do very little to detract from the very
high quality of the performances. Careful
selection and editing has resulted in a collection of twenty-three tunes that offer not only
a remarkable representation of the Convention but also a widely varied collection of
first rate talent.
JAll and all that
Bertram Stanleigh
Joe Pass: For Django
Pacific Jazz Stereo ST 85
Pass has made a very substantial impression on the jazz scene in the last three years,
but nothing on his previous recordings has
prepared us for the deeply felt, finely executed
performances on this tribute to the late
Django Reinhardt. With the exception of
Django, by John Lewis, and Pass's own composition, For Django, all of the tunes are
either by Django or are familiar specialities.
There is much of the same improvisational
approach in Pass's performances as there was
in those of Django, but these are more vigorous, extrovert interpretations. They do, however, have that gentle quality that was a
hallmark of Reinhardt's work, without being
in any way imitations. For accompaniment
John Pisano plays rhythm guitar, and the
quartet is completed by Jim Hughart, bass,
and Colin Bailey, drums. They supply a solid
rhythmic background with none of the arch
effects that so often marred the work of the
Quintet of the Hot Club of France. Sound on
this release is up to the high level of the
performances, with Pass solidly placed midway between the speakers, bass and guitar
on the left and drums on the right.
Herbie Hancock: Empyrean Isles
Blue Note Mono 4175
Four numbers by Herbie Hancock receive
flawless performances by Freddie Hubbard,
cornet, Hancock, piano, Ron Carter, bass, and
Anthony Williams, drums. As in previous releases, Hancock and Hubbard play with imagination and work superbly together. The liner
notes offer a detailed programmatic description of the four numbers, relating them to a
fanciful legend of four islands in the "Great
Eastern Sea." While the story is not without
charm, it would be a mistake, I think, to try
to relate the legend to the music. The music is
strong and stands on its own, without need
of a literary crutch. The recording, as is usual
with Blue Note, is exemplary.
Les McCann: McCanna
Pacific Jazz Stereo ST 84
According to McCann's own liner notes, the
inspiration for this set was found in some
Zulu performances that McCann saw and
heard in the African Pavillion at the New
York World's Fair. Several of the numbers by
McCann have been awarded African titles
Zulu, Basuto Baby and Narobi Nights. Bonga,
Conga and timbales have also been added to
some of the rhythm accompaniments to
heighten this African effect. But somehow it
-
doesn't come off. It's not that the record isn't
a good one. Les McCann is a first rate pianist,
and the present platter compares favorably
with his other work. But somehow no special
quality of African nature gets across.
John Wallowitch: This is John Wallowitch
Serenus Mono SEP 2005
Well, not every Philadelphia -born musician
seems to have come under the Coltrane influence. Here's a Philadelphian whose background would appear to be classical, rather
than bop. He's represented by a collection of
pop and standard numbers that are billed as
"where pop music will go when it finally gives
up. He is what happens when you get tired
of jazz." What happens in this case is a
series of improvisations in the style of Rachmaninoff. That they rise above mere routine
is largely due to an impressive technique and
a Large, round tone. There is much enjoyment
to be derived from the sheer sound of the
instrument and the excellent reproduction it
receives in this recording.
DePaur Chorus: Songs of New Nations
Mercury Stereo SR90382
These are fresh, bright, vigorous performances of African and Israeli songs and dances
performed with excitement by an excellent
group of singers augmented by native drummers and percussion. The recording is rather
a surprise to one who is used to hearing music of this type in technically inadequate field
recordings. The present release is the ultimate
in up to date recording technique with some
of the best sound I have yet to encounter on
an 1p and with an ideal stereo spread from
speaker to speaker. The music ranges from a
15th century Ashanti war chant from Ghana,
with a stunning drum accompaniment, to a
poignant 19th century Zionist song from
Israel, to a rollicking fun song from the
Congo, to a strongly rhythmic courting song
from Nigeria. All of the numbers are unfamiliar and unhackneyed, and the collection
presents a wide variety of interestingly contrasted material. The arrangements are simple and effective, and the total impact of this
recording is truly awesome.
Richard Dyer -Bennet: Songs of Ships, Seafaring Men, Watery Graves, Card
Sharpers, A Giant Ram, An Indian
Scalping, and One Edible Rat
Dyer-Bennet 12
Richard Dyer -Bennet is an endless source
of stylish, impeccably polished performances
of folk material. The present disc-which
probably offers the longest title of any disc
in the Schwann Catalog
a collection of
largely familiar sea chanties, with a few extra
items added for spice, among them Dyer -Bennet's own setting of a Bret Harte poem,
Plain Language from Truthful James. Both
the virtues and shortcomings of this major
folk artist are too well known to bear repeating in each review. This is an artist who has
set a special high standard for himself, and
through the years he has been able to maintain that standard. His is an unchanging art,
and his vocal resources remain both as
flexible and limited as ever.
-is
Galax, Va., Old Fiddlers' Convention
Folkways Mono FA 2435
Fiddle and banjo combinations were probably the earliest American musical ensembles.
They have both a long tradition as accompanying instruments for group dancing and
as instruments for concerts and home entertainment, and the tradition of performing
competitively is almost as old as their popularity. The Old Fiddlers' Convention at
Galax, Virginia has been held for the past
twenty -eight years. Sponsored by the Galax
Lodge of the Loyal Order of Moose, it attracts an abundance of old time performers
more than a hundred contestants compete
each year -and both traditional and bluegrass banjo styles are represented in separate
categories. The present recording was collected at the 1961 to 1963 Conventions and
includes such well known performers as Tom
Ashley, Larry Richardson and The Stony
Mountain Boys. Many performers with impressive local reputations are featured, among
them, mandolinist, Ivor Melton and old time
banjo player, George Stoneman. Perennial
-
62
Roland Kirk: Gifts & Messages
Mercury Stereo SR 60939
Most of the authorities are agreed that
Kirk's simultaneous performances on flute and
manzello and on stritch and slide whistle
are serious creative works to be pondered
diligently for their cerebral content, but this
listener can find little in Kirk's instrumental
gymnastics other than flashy exhibitionism
and a prodigious technique employed for its
own ends. Certainly he manages to contribute nothing in March on Swan Lake or
My Heart at Thy Sweet Voice. His flute
solo of Bechet's Petite Fleur is not only
dull but too closely miked and overly
breathy. On the other hand, Hip Chops
and Gifts and Messages seem pleasantly agreeable highjinks that can be enjoyed in a
superficial way by those of us who lack the
insight to appreciate their more profound
message. Aside from a tendency toward extremely close miking that results in overly
directional stereo, the recording is fine.
Richard "Groove" Holmes: Book of the
Blues, Vol.
Warner Bros. Stereo 1553
This record is a real sonic experience with
strong, low pedal notes, bright, crisp cymbal
shots, a very wide dynamic range and excellent separation. The music's good, too. Holmes
fingers his way through a collection of traditional blues numbers that includes See See
Rider, Mean Old Frisco, I'm Gonna Move on
the Outskirts of Town and How Long. He
conveys all of the proper low down qualities,
he swings and he even adds a bit of boogie.
This isn't jazz for purists, but its highly
enjoyable music for audio fans, particularly
those who are anxious to show off their
woofers. Equipment dealers would be wise to
keep a copy on hand.
1
Robert Wilkins: Memphis Gospel
Singer
Piedmont Mono PLP 13162
From 1928 to 1935 Reverend Wilkins recorded a number of Gospel songs for Victor,
Brunswick and Vocalion, then, like a number of jazz and folk performers, he disappeared from public view until early 1964
when he was located by Piedmont Records,
acting on a tip from Bill Givens of the Origin
Jazz Library that Wilkins was rumored to
be living in Memphis. A check in the Memphis
phone book and brief correspondence led to
a trip to Washington for the present recording. Since I'm not familiar with Wilkins'
earlier waxings, I can only judge from the
present disc. The strong rhythm of his own
guitar accompaniment and the depth of feeling in his performances suggest that in his
earlier days he was a powerful singer of
gospel blues. In his sixty- eighth year, Reverend Wilkins has a voice somewhat rough and
small, but he is a skillful performer who
manages to achieve a great deal of variety
in spite of his limited vocal resources, and
his command of his guitar cannot be faulted.
In addition to two traditional numbers, Just
a Closer Walk with Thee and Do Lord Remember Me, Wilkins is heard in six of his
own compositions. Most interesting is The
Prodigal Son, a highly individual retelling
of the Old Testament story that extends for
ten minutes over the greater portion of side
Rev.
two.
AUDIO
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
Valentina Felix: Song of the Sea and
Other Portuguese Songs
Monitor Stereo MFS 421
collection of currently popular Portuguese fados and one or two other pop numbers that were getting lots of local air time
in Lisbon during the past year, the present
disc features one of the most promising of
the younger fadistas with an orchestral accompaniment that is more likely to appeal
to the average Portuguese platter buyer than
to the folk music purist in the United States.
If these are not classic fados, they are non theless, well knit, tastefully arranged performances of a type more popular in their
native country than those with the typical
guitar background. Miss Felix nods twice in
the direction of her American audience, once
in a number called Fado Twist and a second
time when she offers the brief final stanza
of the title tune in English. I was secretly
pleased to note that her pronunciation of our
language is almost as inept as mine is of
hers.
A
Mike Hurley: First Songs
Folkways Mono
FG
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3581
Back in the United States -Frederic Ramsey Jr., whose field recordings in the backwoods of the South have brought to light
some of this country's most interesting, authentic folk talents, has made an exciting
new find-not on southern safari, but in his
native Bucks County, Pennsylvania, where
be encountered Mike Hurley. At 22, Hurley
was worn out from too much hard living
in Greenwich Village and New Orleans and
had retired to a small stone house in the
country to recuperate, following six months
in Bellevue Hospital where he was treated for
hepatitis, tuberculosis and mononucleosis. On
Ws first disc, Hurley makes a strong impression as an imaginative creator of highly
original songs on a variety of personal experiences. His subject matter extends from
interrupted local railroad service, to interplanetary flight, to werewolves, to the consumption of tea, of wine and to a number
called You Get Down by the Pool Hall
Clickety-Clack (Sister Song), whose theme is
expressed in the telling couplet :
You wrote my sister a twelve -line sonnet
There's a train leavin' here, and I want
you on it.
Imagination as a song writer is Hurley's
strongest claim for recognition. At a time
when most young folkniks are content to rehash the same old tired themes that reflect
the experiences of other persons, rather than
their own problems, this young man has found
a variety of new subjects on which he can
express himself in a strongly personal manner. Both as a writer and as a performer he
displays less control than one expects in a
mature artist, but this is only his start, and
any lack of polish is more than compensated
for by an abundance of talent. Mike Hurley
has so much to say that further recordings
are eagerly anticipated.
Yulya Sings Kalinka and Other Russian
Folk Songs
Monitor Mono MF 422
In her fourth recital on Monitor, this
charming young singer digs into more of the
standard Russian folk song repertory with
decidedly happy results. In addition to Kalinka, she contributes idiomatic versions of
The River Flows, I Planted the Little Garden
Myself and eleven more folk ballads. To each
of them she contributes not only the proper
style and expression but also the personality
of a dynamic performer and the voice of a
talented singer. Her dark, throaty sound can
be languid and caressing in a romantic number or vigorous and robust in a rhythmic
tune. As on all Monitor folk records, full
song texts are supplied in English and the
language of the performances. In this instance, the Russian texts are given in both
the Cyrillic alphabet and in a Roman transÆ
literation.
A powerful 70 -Watt Amplifier plus Complete Preamplifier Control Facilities plus a Standard AM Tuner
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AUDIO
FEBRUARY, 1965
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THIS SPACE CONTRIBUTED BV THE PUBLISHER AS A PUBI
IC
SERVICE
InZide Audio
LARRY ZIDE
This month will be devoted to a pot
pourri of things audio. First among
these is mention of a press preview I re-
Don't ever go away
again, daddy !
cently attended. This was produced by
Empire's energetic President, Herb
Horowitz. A number of audio editors
and columnists were gathered together
at Alitalia's VIP lounge in Kennedy
International to act as judges in a revival of a highly successful contest held
once before by Empire. In this contest,
the consumer must match a list of Grenadier speaker qualities against a composite master list arrived at by the
judges. Each judge rated the features
he considered most important on a 10point scale. Since the composite master
is to be compiled by an "independent
agency," the judges do not know what
the master list looks like.
The prizes of this contest include a
trip to Europe with a tour of the music
festivals as the principal feature.
I applaud this. It is good to see a
major component company demonstrate
its belief that the high -fidelity component purchaser is (or ought to be) a
music lover. I dwell on this subject because I feel it to be important to the
future of componentry. I became involved in the high -fidelity field because
it was a means to an end. That end, for
me, is the most natural and realistic recreation of music in the home.
Some manufacturers have wandered
away from this basic. It is time to return. Music is the end. Components are
the best way toward that end. It is
gratifying to see Empire building a
campaign around music. May their tribe
increase!
What Price Progress?
Her Dad is sensible. He went to
his doctor as soon as he noticed
a cancer danger signal. His cancer was therefore discovered in
its early stages, when prospects
for cure are more favorable.
If you don't know Cancer's 7
Danger Signals, call your local
American Cancer Society Unit
today. Play it safe and see your
doctor for an annual
health checkup, too. And
help research and education save lives by sending
your check to "Cancer;'
c/o Postmaster.
AMERICAN CANCER SOCIETY
I often find myself asked, by interested friends, if a particular piece of
equipment is worth the asking price.
Something of a peak in frequency has
been reached on this question with the
long -awaited release of the $650 Marantz
tuner. At that price this tuner stands
well above the pack. The question is, of
course, is it worth it?
An answer must be based upon an
assumption. That being that this tuner
is a significant and recognizable improvement in the state of the art. In
other words, if the tuner will perform
better than others we can draw a conclusion as to worth. Let us then proceed
based upon this, as yet unproved, as-
sumption. Audio components today are
pretty sophisticated devices. Of course
there is always room for improvement,
but most improvement today is the kind
that is audibly subtle. Any dramatic
breakthrough means (almost of necessity) a radical approach to design. This
is what Marantz purports to have done.
There have been "state -of- the -art"
components before, which have been
succeeded by new units during the inexorable march of time. But no truly
great product can ever be totally obsolete. Here lies the heart of the price
question. I believe these super units to
be worth the money that is asked for
two reasons. First, because you really
cannot set a price on a true advance in
listening and performance pleasure.
Second, these units, just as a Rolls Royce, offer a unique grade of continuing satisfaction. This quality is priceless.
Some Thoughts on "Solid State"
There has been much written about
"transistor sound," particularly as applied to amplifiers. I must agree with
much of the commentary. The best solid state amplifiers certainly sound different
from the best vacuum tube units. I have
heard instrumental clarity from solid state amplifiers that has been very
gratifying indeed. At the same time, I
have heard some solid -state equipment
which left something to be desired.
Why? Some say high IM at low output
levels, others say crossover distortion,
still others say, "Nonsense," its all in
the mind of the listener. Nobody really
knows for certain.
I want to emphasize that transistor
amplifiers are not necessarily inferior
to tubes nor vice-versa. Rather, that
"transistor sound," when very noticeable, may not be an improvement in
sound reproduction but rather the opposite. Of course new solid-state amplifiers
are being issued at a furious pace. And I
have heard preproduction units that
meet the promise of transistors and then
some. In amplifiers, then, I feel that
transistors have not yet reached full
promise. But I expect to eat these words
any day now.
Preamplifiers, on the other hand, are
a different matter. I have heard several
solid-state units that are, in all musical
respects, sonically superior to the best
tube units. But, some care in selection
has to be made. Many solid -state pre amps do not have as much dynamic
AUDIO
64
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AmericanRadioHistory.Com
FEBRUARY, 1965
range at the phono input as do the best
tube units. In other words, the phono
inputs of such units may be overloaded
and start clipping when fed from a high
output cartridge playing a record with
a high recorded velocity. To be more
specific, good tube units will not overload until 150 millivolts or more are fed
in. Some of the transistor units will
overload at 35 to 50 millivolts, and, as a
result, can produce distorted sound with
some cartridges playing some records.
It is said that an average magnetic
cartridge has an output of only 4-5
millivolts. True enough, but this is an
average output. Musical peaks can run
as high as 8-10 times that value. This
makes 40-50 millivolts a minimum figure.
After all there are some cartridges that
can put out up to 15 millivolts under
average conditions.
Preamp manufacturers must make
sure that their products will not overload when fed phono signals of the orders indicated. My experience has been
that not all manufacturers have been
overzealous on this point.
I have left tuners for last because
they are the most controversial. Solidstate tuners can provide very excellent
performance characteristics indeed. The
heart of the disagreement seems to center
on the tuner's "front end." Here, many
engineers contend that transistor tuners
suffer from crossmodulation problems
and also an inability to handle signal
overloads (much the same as phono pre amps). The latter can be attended to, in
large part, by sensitivity switches ; the
former is for the engineers to argue.
My ears tell me that there are solid state tuners that perform as well as
similarly priced tube jobs. And, the
solid -state units have the theoretical edge
in reliability and durability.
For the bulk of integrated equipment
sold today, solid -state is a distinct improvement over tubes. I have seen several
transistor receivers, for example, that in
all respects rival (and occasionally surpass) their tube equivalents.
But for the super units, the best preamps and amplifiers, and so on, there is
still some more to go. I expect that there
will be more to say on this subject at
regular intervals.
AUDIO
This book is for the hobbyist and
technician who wants to know the
plain and simple approach to
HIGH FIDELITY
TROUBLESHOOTING
AMPLIFIERS.
Written by Mannie Horowitz, his
fact -filled, illustrated chapters
spell out the most direct approach
to curing both, vacuum tube and
transistorized amplifier ills. Everything from instruments and test
procedures, to servicing transistorized stereo amplifiers, is covered in a writing style that makes
it easy to read and absorb.
ETC
(from page 12)
that my friend the Old Lady of Forty Second Street, the famed automated subway train, has ceased to exist. She got
her skirts severely burned, not to mention most of her circuits, in a big fire last
year ; since then she has been quietly retired. She was a splendid example, it
turned out, of worthy but not- yet-quitesatisfactory computer thinking, an attempt to take over too much from the
live sort. As previously described here
(from first -hand experience), she bungled
the job of being her own motorman. A
live, well -trained motorman can still do
this kind of control job more accurately,
more simply, more responsibly, and more
economically (probably). Starting, running and stopping a big train full of
perishable people is no joke. The nonhuman computer "motorman" had no
choice (with its limited decision -ability)
except to proceed with enormous caution, in fits and starts, wasting an unconscionable amount of time en route.
The human mental feedback and action response pattern of a real motorman
here is superior to the computer's
Driving a train is one of those things
we can do best ourselves via so- called
intuition, which is merely a word for
massed, semi-instantaneous decision -making-plus- action out of enormous amounts
of mentally -stored memory and experience.
(On the other hand, the elevator
people have done an admirable job with
their rather simpler computer-type problem, the automation of vertical trans-
AUDIO
port. They are far ahead of any live
elevator operator.)
$0.00
Another humorous instance I'm happy
to cite was the splendid snafu of my New
York bank account perpetrated recently
by my bank's computer system.
It seems that these accounting machines are programmed so that if your
balance reaches the mystic figure of
$0.00 at any moment, even for a millisecond, for any reason, the account is
instantly closed. You disappear. Well,
by the sheerest of coincidences last fall
I just happened to hit the magic figure,
between deposits and withdrawals. I
didn't know it, nor did the bank people.
So in a fleeting instant of time I vanished
from the face of the earth and was no
more.
My successive deposited checks were
held in abeyance" by the computer, without my knowledge or the bank's. Nobody
knew, because the machine, not being
reasonable, didn't figure it was supposed
to tell anybody. It didn't. After a month,
it turned out, the computer had decided
(according to program) to release me
back into this world; but it then made a
second silly mistake; it didn't tell the
bank what it had done, nor that the bank
should please resume sending me monthly
statements.
So after three months of no statements and a brace of mysteriously uncredited deposits of cash (I went right on
depositing and withdrawing all this time
FEBRUARY, 1965
TROUBLESHOOTING HIGH FIDELITY
AMPLIFIERS was written specifically
for the service technician and the
audio hobbyist who specializes
or wants to specialize
the
growing and highly profitable field
of audio and high fidelity service
-in
-
and repair.
A
wealth of information
a perfect gift!
-makes
only $2.95- Use convenient coupon
below, just enclose your remittance
-we pay the postage.
Radio Magazines, Inc., Dept. T62
P.O. Box 629
Mineola, New York, 1502
1
, please send
am enclosing $
me
copies Of TROUBLESHOOTING
HIGH FIDELITY AMPLIFIERS *, by Mannie
Horowitz.
I
NAME
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65
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and nobody said boo), I went in and
made a fuss. Was the computer's face
red. So was the bank's.
P.S. I'm still getting no statements.
They must need a new model.
some computers, and I say that it's still
a good idea to use them once in awhile
Feb. 32nd?
By the way
like sound -alike speakers (see Ammo ETC Dec. 1964).
Some of my good readers got the erroneous impression that because I compared them to so many look -alike impersonal Madison -Avenue executives, I
disapproved of their sound. Oh no. Not
Then there was this New Jersey computer that got is programme mixed and
didn't know how to think it out. Reminds
me of my brother who as an advanced
schoolboy and ready for college still
couldn't recite the months of the year
in the right order. It was a subject that
simply didn't interest him. You can lead
a horse to water... .
Well, this N.J. computer was the
same, or its master was. The machine
didn't know about the months. And yet
somebody, with callous disregard of its
lack of a primary education, put it in a
responsible executive position. Terrible.
One fine month, recently, it sent out a
million or so (well, thousands) of
driver's licence renewal applications, all
of which announced that the owner's
license was about to expire on November
31. The Motor Vehicle people didn't
have an inkling, natch, until some irate
human computers called in (via automated dialing) to complain. Or just to
guffaw.
I do love computers, I really do. Also
people. But people (that is, some people)
have better checks and balances than
in positions requiring responsive thinking of the human sort.
-I
at all.
I won't venture any opinion as to
whether Madison Avenue people should
or shouldn't wear gray- flannel suits but,
if you did by any chance misunderstand
me, I must state in no uncertain terms
(imagine having to!) that loudspeakers
should sound alike.
That is, unless we aim to deny that
there is only one hi -fi god, old Hi -Fi himself, that impersonal ideal of scientific
perfection. I'm all for lots of gods when
it comes to the matter of taste -say, in
recording techniques, liveness. And I
can take a lot of assorted distortion when
it comes to a working compromise with
absolute perfection since, as is well
enough known, the human mind and its
ears are very good at masking one sort
of sound in order to appreciate another
which they particularly like. (A tiny,
insufficient speaker can make a fine im-
The First Book of its Kind -No Other Like
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SOUND in the THEATRE
by Harold Burris -Meyer and Vincent Mallory
Nothing like SOUND in the THEATRE
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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 de-
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Send my copy of
1
rived systems and equipment specifications.
Complete procedures are given for: Planning,
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Operation and maintenance of
sound control equipment.
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AR Library Vol.
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70 pp., illus., paper $1.00
A layman's practical guide to high fidelity installation. We think that it will become a
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If this doesn't give you a roadmap into the
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can Record Guide:
I
REPRODUCTION OF SOUND
by Edgar Villchur
AR Library Vol. 2
93 pp., illus., paper $2.00
Vol. 2 explains how components work rather
than how to use them, but it presupposes no
technical or mathematical background. Martin
Moyer writes in Esquire: "far and away the
best introduction to the subject ever writtenliterate, intelligent and, of course, immensely
knowledgeable." From HiFi /Stereo Review:
"just the books to satisfy that intellectual itch
for deeper understanding."
RADIO MAGAZINES, INC.
P. O. Box 629, Mineola, N. Y.
Please send me the
following:
Allison's "High Fidelity Systems
A User's Cuide" at $1
Roy
-
Edgar Villchur's "Reproduction of
Sound" at $2
in bills, money order,
I enclose $
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NAME
AUDIO
Address
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ADDRESS
U.S.A.\
Name
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HIGH FIDELITY SYSTEMS
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.
An
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-
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MAGAZINES, INC.
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FEBRUARY, 1965
pression if you put it in an excellent
listening place.)
BUT as far as sheer transduction is
concerned, the passing along of a given
sound -signal, its translation into acoustic
motion, I admit only one standard, as
don't we all. And by that idealistic standard, all speakers should be "sound transparent"-pass on the electrical signal with NO change whatsoever in wave shape, etc. None at all. That's the hi -fi
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So you see, natch, I like sound -alike
speakers. And on sheer principle I disapprove of all speaker "color," of whatever sort. But a lot of people still enjoy
those colors. And so, since I also like
people, I have an indulgent feeling about
individually colored speakers. They fill
a need! (But I still think they're on the
way out, by simple popular preference.)
All clear?
SOLID
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FIDELITY
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e.
The Right Stepup Transformers
Q. I am using two ribbon microphones
and stepup transformers to feed my
stereo tape recorder, but cannot get
enough gain wtihout placing the mikes
unduly close to the instruments to be recorded. Pianos especially lose their tonal
balance and produce key thumps at this
close distance. Can you suggest any
modifications in the system that will provide more gain?
A. It may be that the stepup transformers are not just right for your
particular microphones. I suggest that
you consult the microphone manufacturer, informing him what transformers
you are using and asking if you could do
better. It may be necessary for you to
purchase an active microphone mixer
that provides gain.
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Tape Head Gap
Q. I have a tape machine that uses
separate heads for recording and playback. However, both heads are of the
same type with a gap width of 0.17 mil.
Assuming that the electronics is capable
of matching the impedance of a different
record head, would there be an advantage
in replacing the 0.17 mil record head
with a wider one, say 0.5 mil? Is there
an optimum width for recording and a
different optimum for playback?
A. In terms of microinches, heads built
specifically for recording usually have a
gap between 250 and 1,000 microinches.
Those for playback or record -playback
have a gap between about 40 or 50 and
150 microinches. Your heads, with gaps
of 170 microinches, appear to fall between the two categories. A narrow gap
FEBRUARY, 1965
IF
112 WATTS INTO 4 OHMS,
72 WATTS INTO 8 OHMS,
IHF MUSIC POWER.
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requisite for high- frequency response
in playback. To maintain playback response to 15,000 cps, the gap should be
about 250 microinches at 7.5 ips and
about 125 microinches at 3.75 ips. A
relatively wide gap is desirable in reis
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cording, because the narrower the gap
the less efficient is the head. In other
words, the narrow gap tends to act as
a short circuit. The less efficient the record head, the harder the record electronics has to work to supply the necessary
amounts of bias and signal current. If
your record electronics has ample driving
power at low distortion, I don't see that
you have much to gain by changing your
present record head.
Crossfield Recording
Q. I have read of a new recording
technique referred to as the crossfield
system. Can you enlighten me about it?
A. The crossfield head is a development of the Research Institute of the
Illinois Institute of Technology, Chicago, Illinois. The development is over 10
years old. As embodied in at least one
well-known tope recorder, an extra head
MAGNETIC TAPE
ENGINEERS
manufacturers of
magnetic recording tape, is expanding its
technical staff, and has openings for chief
chemical, electronic and mechanical engiGreentree Electronics,
neers with experience in the production of
magnetic tapes. Data and instrumentation
tape experience is desired, but not essential. Excellent salary for the right man
plus exceptional opportunities for advancement with this rapidly expanding company.
Plant is located in beautiful oeeanside resort community, less than 45 minutes from
Los Angeles. All replies and interviews
will be kept confidential. Write to C Alan
Lindquist, V.P. & Dir. of Mfg. and Eng.,
Greentree Electronics Corp., 2135 Canyon
Drive, Costa Mesa, California, 92627, or
call collect 646 -2453 (Area code 714).
build
your own
bozak
AUDIO DESIGN ENGINEER with
manufacturing supervision experience. Area
Orange County, California (near Los Angeles). Please state qualifications and salary required. Box CB -3, AUDIO, P. O.
URBAN OR EARLY AMERICAN
INFINITE -BAFFLE SPEAKER CABINETS
For the Bozak 2 -way B 300
and 3 -way B -302A Speaker
Systems. Complete Kits for
easy assembly and finishing.
See your Franchised Bozak Deafer
/
DARIEN
/
/
CONNECTICUT
Circle 142 on Reader Service Card
Box 629, Mineola, N. Y.
CLASSIFifD
Rates: 100 per word per Insertion for noncommercial
advertisements; 250 per word for commercial advertisements. Rates are net, and no discounts will be
allowed. Copy most be accompanied by remittance In
full, and must reach the New York office by the
drst of the month preceding the date of Issas.
HIGH FIDELITY SPEAKERS REPAIRED
AMPRITE SPEAKER SERVICE
168 W. 23rd St., New York 11, N. Y.
CH 3-4812
HARPSICHORD. Same as owned by Philadelphia Orchestra and RCA Victor. In kit form
for home workshop assembly, $150. Clavichord
kit, $100. Free brochure. Write : Zuckermann
Harpsichords, Dept. R, 115 Christopher St.,
New York 14, N. Y.
LEARN WHILE ASLEEP. Hypnotize with
recorder, phonograph Details, strange catalog
free. Sleep-Learning, Box 24-AE, Olympia,
Washington.
!
FREE Send for money -saving stereo catalog A2M and lowest quotations on your in!
dividual components, tape recorder, or system
requirements. Electronic Values, Inc. 200 West
20th St., New York, N. Y. 10011.
HI -FI COMPONENTS, tape recorders, at guaranteed "We Will Not Be Undersold" prices.
15 -day money -back guarantee. Two-year warranty. NO CATALOG. QUOTATIONS FREE.
HI- FIDELITY CENTER, 1797 -V 1st Avenue.
New York, N. Y. 10028.
HI -FI SPEAKERS EXPERTLY REPAIRED
USED SPEAKERS BOUGHT
AUDIO SPEAKERS TECHNICS
22 Astor Place, New York 3, N. Y.
AL-4-2140
Let prerecorded tape do the HYPNOTIZING
and then give you control of the subject.
Highly effective. $5. Pioneer Electronics, 1708
E. Woodland, Ponca City, Oklahoma.
Magnecord 728 -44. 3 new heads
used since. A superior machine in superior
condition. $650. O. L. Ricker, 153 Lafayette
S. E., Grand Rapids, Michigan.
SELL
:
latest models, and factory reconditioned. Not
RADIO -TV ANNOUNCING. Forceful public
speaking Highly effective, personalized, taped
home training. Write Hal Fisher, 678 Medford, A, Patchogue, New York 11772.
!
:
CROWN Model GCSX deluxe stereo tape recorder for sale. Speeds to 15 ips, reels up to
10 ". With instrument manual, case. $285.
Roger Modeen, 12045 3rd Avenue, South,
Seattle 68, Wash.
FOR SALE : 1 Grado tonearm, $10 1 Empire
arm, $10 ; 1 Koerting tape deck, Model ME114, $130; 1 Concertone 400 Cosmopolitan
portable tape recorder, $100 ; 1 Telefunken
Magnetophon 75 tape recorder with foot pedal
and headphones. $100. Send inquiries related
to the preceding items to : Box CB -1, AUDIO,
P. O. Box 629, Mineola, N. Y.
SELL : Marantz Model 3 electronic crossover. Factory walnut enclosure. Perfect condition. $100. Joe Fasano, 2123 18th South,
Seattle, Wash. 98144.
AUDIO ENGINEER. Producer distinguished small record label, seeks wider
scope for abilities and experience. 13 years
professional custom recording all types of
music; extensive knowledge fine music, all
periods. 22 years designing, building, improving, servicing audio equipment to professional standards. Resume Box CB -2,
AUDIO, P. O. Box 629, Mineola, N. Y.
FOR SALE : Enclosed seven -foot cabinet relay rack, Bud type CR-1773GH. Deluxe type,
ray hammertone, with casters and rear door.
Like new, original cost over $75. Will sell to
highest bidder who can pick it up. Peter A.
Stark, 519 East 86 Street, New York, N. Y.
ADD PROGRAMS of continuous, commercial -free music you are now missing through
your FM tuner with our sub-carrier detector
plugged into multiplex output of tuner or
wired into discriminator. Detector, self powered, permits reception of popular background music programs now transmitted as
hidden programs on FM broadcast band from
coast to coast. Wired unit, $75. Kit, no alignment necessary. $49.50. Music Associated, 65
Glenwood Road. Upper Montclair, New Jersey.
201 744 3387.
MUSIMATIC : FM music without commercials. Easily connected to your tuner. $59.50
complete. Write, Box 343, Reseda, Calif.
10028.
FLUTTER FILTER KIT FOR AMPEX 600
601, 602 $12.50. H. L. Enterprises, 50 Greene
Street, New York, N. Y. 10012. 212 WA 58586.
SWAP or sell new Fairchild 663 transistorized compressor, cost $168. Invite correspondence, swap data and tapes, with advanced, well-equipped hobbyists interest in
compressed classical background, sleep, chamber and baraque music. Box 156, Weslaco,
Texas 78596.
AUDIO
68
www.americanradiohistory.com
AmericanRadioHistory.Com
FEBRUARY, 1965
Triple
your
tape
recording
fun...
buy
three
tape reelsnot
/j, just
CiO
one!
TARZ/AN
You'll have more fun with your tape
recorder if you use it more frequently.
Always keep an extra supply of tape on
hand, so that you're always ready to
record!
Take this good advice: When you buy
tape, buy at least three reels. And buy
brand -name tape, so you can be confident of its quality, certain it won't
harm your recorder.
Of course, we hope you'll choose
Tarzian Tape. We thoroughly test other
brands along with our own -and the
impartial equipment in our labs assures
us that you can't do better.
FREE: Our 32 page booklet
11
tells you how to get more
out of your tape recordings.
Write for your copy.
SARKES TARZIAN, Iluc
World's Leading Manufacturers of TV and FM Tuners
Closed Circuit TV Systems
Broadcast Equipment
Air Trimmers Semiconductor Devices
MAGNETIC TAPE DIVISION
BLOOMINGTON, INDIANA
Export: Ad Auriema, Inc., N.Y.
Canada: E. I. Piggott Enterprises Ltd., Toronto, Ont.
Circle 143 on Reader Service Card
AUDIO
FEBRUARY, 1965
is mounted opposite the record head and
applies bias from the base side of the
tape rather than from the oxide side. It
is claimed that bias current so applied
maintains its benefits so far as increasing output and decreasing distortion are
concerned, but results in less high -fre-
Assemble the finest instrument
your money can buy
NEW ALL - TRANSISTOR
V t%ht7iel;
quency loss due to "bias erase." For
further information I suggest that you
write to the Research Institute.
ELECTRONIC
ORGAN
Head Impedance
meets AGO
specifications
I am
trying to match my tape deck;
with suitable tape electronics. The electronics which I am considering purchasing is not recommended for low impedance heads. I don't know the
impedance of the head in my deck,
which is a record- playback head. Can
Q.
New Recital Model
compares musically to instruments
costing
4
times the price!
PIPE
ORGAN
VOICING
-32
separate, distinct
-
in
Recital Model. LIBRARY OF
STOPS *. Kit feature adds
extra plug -in voices
you advise me?
A. If the head in your tape deck is of
the record -playback type, it is high impedance, and the electronics whose purchase you are contemplating should be
suitable. At the same time you should
keep in mind that in matching tape
electronics to tape heads you have the
problems of correctly adjusting the
amounts of audio signal and bias current supplied to the record head, and of
adjusting the record level indicator to
give the proper indication.
-all four
families of pipe tone in all
PIPE ORGAN TONE
models
ALL TRANSISTOR
Models
give instant response,
easier assembly, full 5 year
guarantee
-adds
"auditorium" depth and
REVERBATAPE* Unit
power
Lowered Bias Frequency
Q. I have noticed that in a particular
brand of tape recorder the bias frequency
has been reduced from 100 kc to 65 kc.
Why do you suppose this was done?
Doesn't the reduction leave something
to be desired?
A. The reduced frequency probably
permits more efficient operation of the
erase head. The higher the frequency of
the oscillator current fed to the erase
head, the greater are the capacitive and
inductive losses of this head. Hence the
oscillator has to work harder for a given
degree of erasure, resulting in greater
oscillator distortion and greater recording noise. A bias frequency of 65 kc is
still apt to be high enough to avoid
audible beats between audio harmonics
and the bias signal. Of course, higher
frequencies provide greater assurance
against such beats.
plus FULL THEATRE AND CHURCH VOICING,
PERCUSSION, many other quality features!
How is it possible to acquire the skill
needed to build a splendid organ -without
any pievious knowledge of electronics or
music?
While the complete organ is a complex
instrument, Schober Organ kits are spe-
cially designed for do- it- yourselfers.
Printed circuitry eliminates a lot of the
work and makes errors almost impossible.
Many parts come preassembled. You simply follow detailed illustrated instructions
for easy assembly, then place in assembled
and pre -finished cabinet.
You save costly factory assembly, retail
store markup -put every penny into fine
musical parts. You enjoy the finest instrument your money can buy.
Schober Organ kits cost as little as $550
in kit form, and you may spread this cost
by ordering in sections.
9C
ENE
EQPT.
Art)
NEW YORK,
PROF.
(from page 48)
tables available. We have talked about
this table in the past so we will forego
discussing it in detail. But it certainly
is an excellent start to any record playing system. It is fitted with an Elac STS
222 cartridge which we have also discussed previously.
What is left then is the amplifier-control center. We received our unit minus
speaker systems, although Benjamin informs us that they are available. (Model
%ZQ
CORPORATION
N. Y. 10023
SEND FOR FREE CATALOG
WITH FREE "SAMPLER" RECORD
The Schober Organ Corp., Dept. AE -16
43 West 61st Street, New York, N. Y. 10023
Please send me without cost or obligation
SCHOBER ORGAN Booklet describing
models, easy -play Pointer System, FREE
7 -inch 'sampler" record included.
Enclosed find $2 for high- quality LP 10"
FREE
SCHOBER RECORD DEMONSTRATING all three
models with different music ($2 refunded
with purchase of first kit).
NAME
ADDRESS
CITY
STATE
ZIP NO
Circle 144 on Reader Service Card
J
69
convenient service to AUDIO readers.
A
ï?HE
AUDIO
4
ti
-
Order your books leisurely
by mail
save time and travel,
we pay the postage.
BOOKSHELF
Designing and Building Hi -Fi Furniture
Jeff Markel
Written by a professional
tfmwiÑf*sïisars
hi -fi furniture designer
who has taught furniture
iI
..
design at leading colleges, this book is an au;F17t'ITOßE
thentic reference of value
to the hi -fi fan and professional custom builder.
Covers everything from
types of woods to furniture finishing for the
mechanically adept; de
Maintaining Hi -Fi Equipment
Joseph Marshall
A valuable reference for
anyone whose living or
hobby is servicing hi -fi
equipment. Outlines the
professional approach for
servicing all types of hifi components. Covers
trouble- shooting of elec-
tronic, mechanical and
acoustic problems. 224
pages.
No. 58 Paperback $2.90*
sign principles, styles and
arrangements for the
decor minded. 224 pages.
No. 79 Paperback $2.90*
Here is one single volume
with the most comprehensive coverage of every
phase of audio. Concise
accurate explanations of
all audio and hi -fi subjects. More than 7 years
in preparation-the most
l
authoritative encyclopedic work with a unique
quick reference system for
instant answers to any
question. A vital complete reference book for
5
every audio engineer,
technician, and serious
The 6th AUDIO
The 5th AUDIO
Prepared and edited by
C. G. McProud, publisher
of Audio and noted authority and pioneer in
the field of high fidelity.
Contains a wealth of
ideas, how to's, what
Edited
No. 123 $19.95*
"the best of AUDIO"
-
-
fied. Easy to read and
learn the techniques required for professional
results with home re-
high fidelity and a valuable reference.
No. 124 Volume t $2.00*
MONTHLY SPECIAL! SAVE $5.00
50% with this collection of AUDIO books.
"best of AUDIO" ($2.00)
5th AUDIO ANTHOLOGY ($3.50)
McProud High Fidelity Omnibook ($2.50) and
Tape Recorders 5- Tape Recording ($2.95)
Save almost
TOTAL VALUE ALL FOUR BOOKS . . . $10.95
Your cost only . . . $5.95 Postpaid
CIRCLE OS400
This offer expires February 28, 1965, and
is good
only on direct order to the Publisher.
AUDIO Bookshelf -RADIO
MAGAZINES, INC.
O. Box 629, Mineola, New York 11502
full remittance of $
58
125
79
127
have circled below.
112
130
v
I
*All U.S.A. and Canadian
orders shipped postpaid.
--
AUDIOGUIDE
1962196.1
mote
AV
._
-
rmraurf
--
TAPE RECORDER
.
c -r
.
ZIP
i
¡r
11
[LIP
/intdi
.ì
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tT,,,,,
..f^^':
Cr1+r-
$3.30
tp` taw.
-` _,
{'-i
-? .;
ADDRESS
n
NO
U
iO
Getting The Most Out Of Your Tape Recorder
Herman Burstein
t'.
STATE
3rd Edition
tuners, changers, amplifiers,
tope recorders, speakers,
record players, etc. Lots of
ideas for custom installations. Tells how to achieve
concert hall reception in
your home. 216 pages.
No. 142
about
magazine
high fidelity. A 1962 -1963
product review of stereo high
fidelity components. Valuable
reference for the hi g
n
hobh byist .
ity enthusia st ad
Part I contains a thorough
the
Problems
of
discussion of
a Stereo Installation, Part II
is a
complete treatise on
Selecting a Tape Recorder.
Indispensable to the prospective buyer of stereo com
ponents and tape recorders.
Includes a section on where
to buy various stereo hi-fi
components and accessories.
156 pages.
The complete hi -fi story
answers all questions about
,our
OS400
$3.95
the editors of AUDIO, the
original
High Fidelity Simplified
Harold D. Weiler
--
124
NAME
CITY
$1.00
No. 127
By
Written
(No C.O.D. or billing.)
115
123
251
Vitt'
-:-
grsorq dr
am enclosing the
142
of high fidelity: FM STEREO
and TRANSISTORS IN AUDIO
No. 130
most important issues in
$2.95
C. G. McProud,
publisher of AUDIO. Includes
articles on the two most significant milestones in the field
EQUIPMENT. A meaningful
reference for everyone in the
fields of audio engineering,
recording, broadcasting, manufacturing and servicing of
components and equipment.
A necessary book for the
high fidelity enthusiast. 144
pages.
-
techniques, sound effects,
editing and splicing, etc.
Invaluable to recording
enthusiasts.
I
IjU,,
-
AUDIOGUIDE
new compendium of
AUDIO knowledge. Here
is a collection of the
best of AUDIO
The
AUDIO Clinic by Joseph
Giovanelli . . . noted
audio engineer and the
original high fidelity answer -man
EQUIPMENT
PROFILES edited by C. G.
McProud . . . Editor of
AUDIO. Here is a wealth
of hi -fi and audio information. Answers to the
of High Fidelity Simpli-
Please send me the books
--
A
corders. Covers room
acoustics, microphone
P.
_
$3.50
edited by C. G. McProud
A complete book on home
recording by the author
Paper Cover
McProud,
No. 125
Tape Recorders and Tape Recording'
Harold D. Weiler
No. 112
G.
-
No.115 $2.50*
TAPE RÉCORDING
by C.
Anthology
Edited by
publisher of AUDIO. An anthology of the most significant articles covering: stereo
recording and reproduction;
stereo multiplex; measurements; stereo technology,
construction and theory
which appeared in AUDIO
during 1958 and 1959. The
5th is truly a collectors' item
and a valuable reference for
the professional engineer,
teacher, student, hobbyist and
hi -fi fan. 144 pages.
to's, and when to's, written so plainly that both
engineer and layman can
appreciate its valuable
context. Covers planning,
problems with decoration,
cabinets and building hifi furniture. A perfect
guide.
tAPE, RECORDERS,
Anthology
0
,,
audiophile.
McProud High Fidelity Omnibook
'
1280 pages
3400 topics
1600 illustrations
"The AUDIO Cyclopedia"
Howard M. Tremaine
n_
.
i
-..
AJ
ír`ö1Tl
in
"plain talk" for
the man who has or wishes
to buy, a tope recorder. It
answers the myriad cluestions raised by tape recording enthusiasts. Its chapters
cover every phase of opera Lion and maintenance -from
adding a tape recorder to
the hi -fi system, to a thorough dissertation on micro phones. Lots of practical
information on how to buy.
176 pages.
No. 251
$4.25
NOW ... PERFECT FM
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INCO
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Available at your Finco Hi -Fi
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Model 3007
Only $6.95 List
THE FINNEY COMPANY
34 W. Interstate St.
Bedford, Ohio
Circle 145 on Reader Service Card
SAVE over 4 O% hifi
Easy- Pay -Plan -Up to 24 months to pay
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6 month guaranteed repurchase plan
Full 2 yr. warranty -parts and labor
Franchised all lines. We ship from stock
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HI- FIDELITY
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"TRe House Et Lew Lew Prices"
1797 -U 1st Are.
New York, N. Y. 1002E
Circle 146 on Reader Service Card
CANADA
High Fidelity Equipment
Complete Lines
Complete Service
Hi -Fi Records
Components
-
and Accessories
E,LECTROl)O1cE
SOUND SYSTEMS
126 DUNDAS ST. WEST. TORONTO, CANADA
Circle 147 on Reader Service Card
SUPPORT
YOUR
MENTAL
HEALTH
ASSOCIATION
208). Of course this amplifier will operate well with any moderately efficient
speaker system, preferably 8 or 16 ohms.
The amplifier is a solid -state stereo
unit containing 14 transistors, 4 silicon
diodes, and 2 germanium diodes. The
power amplifier is the familiar single ended push pull configuration, preceded
by a phase splitter and driver. The preamplifier is also familiar, consisting of
two stages per channel with the RIAA
equalization in a feedback network over
both stages. The tone networks are
losser type. An auto shut -off circuit is
included which will completely shut off
the system when all of the records have
been played, and the switch is in the
auto position. The auto shut off can be
bypassed in order to use the system for
other than record playing.
The 200 will accept inputs from a high level source and has tape outputs for
recording.
Performance
The performance of the Benjamin
Stereo 200 is quite surprising considering
the rather modest price of the system.
Frequency response was within 1 db
from 20 to 30,000 cps. Power bandwidth
at 1 per cent harmonic distortion was
30 to 18,000 cps. Power output (rms)
into a 10 -ohm load, just before clipping,
was as follows (plus distortion at specific
frequencies) :
frequency
(cps)
20
30
50
70
100
300
500
700
1000
3000
5000
7000
10,000
13,000
15,000
20,000
output
(watts)
3.6
6.4
7.0
8.1
8.1
10.0
10.0
10.0
10.0
9.2
10.0
10.0
9.0
7.2
6.7
New
Futterman
Model H -3 OTL
Stereo Twin -50
Consider
a
vacuum tube
power amplifier so "good" it
can readily prove its absolute
superiority over any other
(whether tube or transistor) on
the market today...Indeed, an
amplifier so "good" that the
line between physical limitation and theoretical perfection
is, for all practical purposes,
erased. In short, consider the
revolutionary new Futterman
Model H -3.
dist.
.see*f.s1
(%)
a frequency response of +0,
db from 5 to 90,000 cps and
db at 200 Kc...with harmonic
With
-0.5
0.55
0.28
0.58
4.4
Intermodulation distortion using 60
and 7000 cps tones mixed 4 to 1, and at
an equivalent sine wave power of 10
watts, into a 10 -ohm load, was 1.2 per
cent. The auxiliary inputs require 200
my to drive the amplifier to 10 -watt output with the 10 -ohm load. Hum level
was 72 db below 10 watts.
Listening tests revealed a solid performer, well able to handle a wide variety
of music recorded. Within its power and
design limitations it is an excellent music
reproducer. Its beautiful and compact
packaging should make it very desirable
for the record collector with limited
space and budget. Circle 224
-3
and intermodulation distortion so
close to zero that it is virtually unmeasurable...with a signal -to -noise
level that is better than 90 db
below 50 watts...with an unprecedented damping factor of 200...
with a square wave response that
has never been approached by an-
other amplifier...with a unique
patented tube circuit that does
not require the distortion-producing transformers that are integral
to all conventional amplifiers...
with a built in stability that is absolute proof against the severest
of load configurations and conditions...with a power output very
conservatively rated at 50 watts
RMS per channel (15 or 16 ohm
load)...with all this, the new Model
H -3 is truly the ultimate amplifier.
Quality construction is basic
to the Model H -3. Every component
and part is made in the U.S. and
is of the highest grade obtainable.
Meticulous care is taken in the
fabrication and testing of each H-3
amplifier and each is backed (except for tubes) by a full two year
warranty.
The price (incl. cage):
$288.
For further details,
write:
Dealer
inquiries
invited
harvard (81
electronics co.
693 BROADWAY, N.Y., N.Y. 10012
Circle 148 on Reader Service Card
AUDIO
FEBRUARY, 1965
71
ADVERTISING
INDEX
-offirstthosechoice
who
Acoustech, Inc.
Acoustic Research, Inc.
Altec Lansing Corporation
Amplifier Corp. of America
Audio Bookshelf
demand the best!
NEW
50
±3
30
1
30
7
60,
Coy. IV,
....
71
THE DVNALIZER
2,
3
56
41
63
Lafayette Radio
46db
Lansing, James B., Sound, Inc.
LTV University
Marantz, Inc.
McIntosh Laboratory, Inc.
5
49
55
66
59
Oki -Chancellor Electronics
57
Inc.
Roberts Electronics
the Psycho- acoustic way to achieve a bright,
bodied easy -to- listen-to, easy-to- perceive sta
sound. The Dynalizer contours your station's
quency response to fully utilize the listening ca,
abilities of your audience. Makes your station
sound really big, big, big even on the smallest
pockort receivers.
51, 53
Newcomb Products Co.
North American Philips Co.
Pickering U Company,
devices which produce a sound easier to
listen to and easier to perceive ... in short
a bright, crisp, lively sound which keeps
your audience listening. This is the sound
you need to help you sell your station to
your audience and to your sponsors.
72
Jensen Manufacturing Company
52db
of unique world- renown audio control
I I l
15
12,000
broad category of psycho- acoustics. Now
Fairchild has harnessed many of these
findings and incorporated them into a line
13
Coy.
71
71
20,000
Now you can fully utilize the listening capabilities of your audience! Scientists for
years have investigated and tabulated the
various phenomena that make people want
to listen. These findings come under the
39
Harmon -Kardon, Inc.
Harvard Electronics Co.
Hi Fidelity Center
56db
10- 100,000 cps; extended range,
5- 500,000 cps. Plug -in circuit modules
are printed on epoxy and gold plated.
Engineered to space craft reliability.
1
71
Garrard Sales Corp.
Gotham Audio Corporation
30,000
The most complete recording instruments ever designed for stereo use.
Audio circuity, ±1/4 db from
61
35
67
Fairchild Recording Equipment Corp.
Finney Company
s/n
3
68
72
Kodak Company
Electronic Instr. Co.
Electro- Voice, Inc.
Electro -Voice Sound Systems
Elpa Marketing Industries
Empire Scientific
Euphonics Corporation
cps
-
2,
EICO
Quarter -Track Record /Play Data
±2
±2
33
68
Eastman
INCOMPARABLE
PERFORMANCE
db
47
Diner's Club
Dynaco, Inc.
800 SERIES
7-1/2
3.3/4
-7/8
68
70
Classified
Crown International
RECORDERS
ips
9
12, 45
Benjamin Electronic Sound Corp.
Bogen Communications Div.,
Lear Siegler, Inc.
Bozak
British Industries Corp.
Solid
State
SS
6
17
THE CONAX
the world- accepted way to control high frequency
spillovers in FM due to preemphasis. Lets your
station maintain real high levels even with brass
and crashing cymbals and still avoid FCC citations.
THE REVERBERTRON
the new compact
reverberation system
37
which gives your sta-
THE HALLMARK
OF CROWN
tion that real big
-
SUPERLATIVE
CRAFTSMANSHIP
Sherwood Electronic Laboratories, Inc.
Shure Brothers, Inc.
Sonotone Corp.
Stanton Magnetics, Inc.
THROUGHOUT!
INDIVIDUAL PERFORMANCE
RECORD SUPPLIED
WITH EACH CROWN
UTC Sound Division
WRITE DEPT. AU -02
YL Acoustic Co., Ltd.
I
1718
N T
E
R
N A T
Mishawaka Rd.
CIRCLE 149
72
Sarkes Tarzian, Inc.
Schober Organ Corp.
Scott, H. H., Inc.
Sennheiser Electronics Corp.
I
O N A
69
69
Coy. II
voice. With the Reverbertron you can
have that Carnegie
11
27
58
43
Hall effect as close as
the gain control on the Reverbertron. And there's
the added plus of an increase in apparent loudness of your station sound due to reverberation,
as originally described by Dr. Maxfield.
28, 29
For complete details on psycho -acoustic sound
that sells write to Fairchild the pacemaker in
18
-
professional audio products.
67
FAIRCHILD
L
Elkhart, Ind.
PRINTED BY BUSINESS
PRESS, INCORPORATED
RECORDING EQUIPMENT CORPORATION
10.40 45th Ave., Long Island City 1, N. Y.
CIRCLE 150
AUDIO
FEBRUARY, 1965
w
r
-
-oath
with the U -15
e "
miconduetor Phono cartridge
r
revolutionary new semiconductor transducer
breaks all barriers that limit existing phono cartridges
PHENOMENAL
f2
13
OCTAVE RANGE
DC to 50 kcps,
db; -6 db at 100 kcps. Smoothest, distortion free sound, to give TOTAL MUSIC RESPONSE.
-
Miniconic Phono System
Low -Mass Tone Arm
with Plug -In
Semiconductor Cartridge
SILICON SEMICONDUCTOR ELEMENTS
First cartridge to employ silicon semiconductor elements.
Delivers fabulous output- 10,000 times the power or magnetic
cartridges. Ideal for transistor circuits, 1000 ohms impedance.
World's most efficient, stable, rugged, hum -free cartridge,
with indefinitely long life.
LOWEST EFFECTIVE TIP MASS
Tracks 40 kcps 2nd harmonic pinch effects of 20 kcps funda.'mental; thus stylus tip stays in groove at all frequencies with
only .5 gram needle force. No shock or modulation noise from
loss of groove contact -gives clean highs on loudest passages
-on outer or inner grooves.
ALL THE COMPLIANCE YOUR SYSTEM CAN USE
MICRO CM /DYNE
25
-
Unequalled tracking ability at low frequencies. More important,
for perfect tracking of the upper register -is the fantastically
high stylus -groove resonance of 47 kcps -more than one full
octave out of the pass band!THIS MAKES A PERFECT MARRIAGE OF STYLUS TIP TO GROOVE -GIVES MUSIC PURITY
AN ENTIRE ORDER OF MAGNITUDE BETTER THAN EVER
Model TK -15 -LS Miniconic Laboratory Standard
Phono System. Consists of U -15 -LS plug -in cartridge with biradial diamond stylus. TA -15 low -mass
tone arm and PS -15 power source. Works into magnetic or auxiliary inputs. With instructions. Shpg.
BEFORE!
ELLIPTICAL BIRADIAL DIAMOND STYLUS
Precision -ground, polished, individually inspected and tested
for perfect symmetry. Two radii, .0002 and .0009'", assist stylus
in reducing pinch effect on inner grooves.
VIRTUALLY NO PLAYBACK LOSS FROM OUTSIDE TO
INSIDE GROOVES -ALL THE RECORD SOUNDS GOOD.
wt.,
3',
lbs. USER NET
.........
87.50
Model TK -15 -P Miniconic Professional Phono
System. As above, but with U -15 -P plug -in cartridge with
USER NET
t
.5
mil diamond stylus. Shpg. wt.,
3', lbs.
71.50
PS -15 Power
Source
4b.
Model CK -15 -LS Miniconic Laboratory Standard
Energy Derived From External Power Source
-thus saving the delicate record grooves. The
U -15 cartridge is essentially a modulating device,
not a reciprocal generator. Miniature type P -15
See your Hi -Fi Dealer
or Write Today for
"The Story of
Euphonics
Minitonic"
Minicool
power source (above) has all cables to plug into
any high -fidelity amplifier. Includes switch to
feed low -level magnetic inputs or high -level
auxiliary inputs.
4-
Phono Conversion Kit. Consists of U -15 -LS cartridge (with biradial diamond stylus) for standard
heads and PS -15 power source. Works into magnetic or auxiliary inputs. With instructions. Shpg.
wt., 2 lbs. USER NET
55.00
Model CK -15 -P Miniconic Professional Phono
Conversion Kit. As above, but with U -15 -P cartridge with .5 mil diamond stylus. Shpg. wt., 2 lbs.
-Cuphonics
M
A
R
R
K
E
Dept. A-2,173 West Madison Street, Chicago, Illinois 60602
T
II
N
USER NET
39.00
NOTE: For broadcast and recording studio use, 16'
low -mass tone arm and or power source with 600ohm output also available. Write for details.
G
Area Code 312,
726 -5831
Circle 101 on Reader Service Card
FACTORY: Guaynabo, Puerto Rico. U.S.A.
E -V TWO's produce a quite spectacular sound
big, low -down bass...that is the best, to my ears, that
Electro -Voice has yet produced."
"In brief, the
Radio -Electronics
}{} Fi/Stereo Review
196<
Fibru.i.y. 1964
February,
with
June, 1964
"...the
E
designers of the
-V TWO were aiming
POPULAR
for a smooth, uncolored
sound, and they have
r
SCIENCE
succeeded very well.
"They effortlessly fill my
large listening room with
reproducer."
clean, well -balanced sound."
1964.
r
Popular Science Publishing Co.. In
"Reproducing test tones,
high fidelity
the Model SIX was found
to have a remarkably smooth,
clean and uniform response
April, 1964
across the audio range!...
But whatever one's personal listening tastes are, it would
seem there is an E -V model to suit them."
"...the
AUDIO
June, 1964
Overall the E -V TWO is
a very smooth and musical
a
without being
Patrician.
A
r
"(I)
IleitÁrd
a
You listen."
April, 1964
1
Electro -Voice Model
SIX is as close in sound to
a Patrician as one can come
( u ide
have found them to
be smooth and easy -to-
listen-to...I found the
top end very smooth and
silky, not overbright, and
also it extended well beLyond the 15 -kc. claim of the manufacturer."
December, 1963
A
If Speakers Could Blush, Ours Would!
E -V
E
TWO
-V FOUR
Read what the critics say about the new E -V TWO, E -V FOUR and E -V SIX acoustic suspension
speaker systems. Then conduct your own impartial listening test. For a complete set of
review reprints, plus the name of your nearest franchised E-V hi -fi showroom, write us today.
E.V
Too. $170.00; EV Su, Á371.25; EN Fo. r, $151.67
ELECTRO- VOICE, INC., Dept. 254A,Buchanan, Michigan
www.americanradiohistory.com
AmericanRadioHistory.Com
49107
gk
YO
SETTING NEW STANDARDS IN SOUND
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