Aug - American Radio History

Aug - American Radio History
MAGAZINE ABOUT HIGH FIDELITY
.
Thieleented Speakers
Motional Feedback in Speakers
)est of each
4 -track
units. With three motors and three
heads, it has virtually every professional
feature you'd want. Yet it's extremely
simple to use. In addition to stereo
record/playback, it also highlights 4 channel playback. The RT-1020H (15, 71
ips) is the high speed counterpart of the
RT -1020L. While the RT -1011 L shares
most of the features of the RT -1020 series,
it does not include 4 -channel playback.
The complete extent of their capabilities
becomes apparent only after you've worked
with them. Then you'll recognize the
magnitude of Pioneer's accomplishment.
The RT -1050 is a 2 -track, 2 -speed
(15, 71/2 ips) 3 -head deck which, like all
all Pioneer models, can handle professional 101/2 -inch tape reels. Its unique
combination of bias and equalization
switching controls give 12 different
settings to optimize the performance of
any tape on the market.
BIAS
ST
STD LH9 LH2
EQ
°5J HI
L.
(IIr,-.,-..ü,'.
12 Bias &
The RT -1050 was specifically
designed for easy operation with a wide
combination of professional features like
extended linearity VU meters with
adjustable sensitivity, mic/line mixing,
pushbutton speed selection and reel
tension adjustment buttons. There's also
an exclusively designed pause control,
and independent control of left and right
recording tracks.
The same 2 -track recording system
studios use for better signal-to-noise
ratios and higher dynamic range is
incorporated into the RT -1050. Yet it can
be easily converted to 4 -track use with an
optional plug-in head assembly. Everything considered, it's the most versatile
open -reel deck you can buy. Professionals
prefer it for its studio -quality performance.
Everyone appreciates its completely
simple operation.
Pioneer open -reel and cassette decks
are built with the same outstanding
quality, precision and performance of all
Pioneer high fidelity components. That's
why, whichever you choose, you know it's
completely professional and indisputably
the finest value ever in a studio -quality
tape deck.
U.S. Pioneer Electronics Corp.,
75 Oxford Drive, Moonachie,
New Jersey 07074.
West: 13300 S. Estrella, Los Angeles
90248 / Midwest: 1500 Greenleaf, Elk
Grove Village, Ill. 60007/ Canada:
S. H. Parker Co.
113
IIJ
Equalization settings optimize
performance.
The RT -1050's 3 -motor transport
system is activated electronically by full
logic, solid state circuitry, triggered by
feather touch pushbutton controls. Its
transport is completely jam- and spill proof, permitting you to switch from Fast
Forward to Fast Rewind, bypassing the
Stop button.
me
nick The Cassette Features You Need
Dolby
Memory
Rewind
Frequency
Response
(Chrome tape)
Peak
Model
CT -9191"
Yes
Yes"
20-17k Hz
Yes
CT -7171'
Yes
Yes
30-16kHz
CT -6161`t
Yes
Yes
30-16kHz
CT -5151
Yes
Yes
CT -4141A
Yes
CT -2121
Yes
Front loading
Wow &
S/N
Flutter
(with Dolby)
(%-WRMS)
Price$
Yes
62dB
0.07
$449.95
Yes
Yes
58dB
0.10
$369.95
No
No
58dB
0.12
$299.95
30-16kHz
Yes
Yes
58dB
0.12
$269.95
No
30-15kHz
No
No
58dB
0.13
$239.95
No
30-16kHz
No
No
58dB
0.12
$199.9511
tt Less
Cabinet
Level
Indicator Limiter
t Not
Plus Ree/Play auto start
shown
Rick The Open -Reel Features You Need
Wow &
Model
Frequency
Response
3dB)
Tape
Speeds
(ips)
(-
Equalization
Positions
(% at highest
speed)
S/N
Mic Line 4-Ch.
Mixing
Play
Price
RP -1050
15, 71/2
30-22kHz
0.06
57dB
Yes
$699.95
RF -1020Hí
15, 71/2
30-22kHz
0.06
55dB
Yes
Yes
$649.95
RT -1020L
7V2, 33/4
40-20kHz
0.10
55dB
Yes
Yes
$649.95
RT-1011L
71/2, 33/4
40-20kHz
3/4
3/2
3/2
2/2
0.10
55dB
Yes
No
$599.95
t Rot
shown
Bias/
Flutter
Dolby is
a
$Prices listed above are manufacturer's suggested resale prices only.
Actual resale prices will be set by the individual Pioneer dealer at his own option.
No
t
trademark of Dolby Labs., Inc.
Bringing you the k
is up to us.
High fidelity is important to us at Pioneer.
It's all we do and it's all we care about.
We are excited that cassette tape decks
have reached a level of performance that
meet the highest standards. We are
excited because we know that it means
more enjoyment for you from your high
fidelity system. We also know that you can
now get more versatility and value out of
your high fidelity system than ever before.
The great advances in cassette
technology have had impact on the reel-
to-reel tape deck concept as well. We
believe that the era of the small,
inexpensive 7 -inch reel tape deck is past.
Neither its convenience nor its performance make it a good value compared to
the new cassette technology. And it is now
possible for Pioneer to offer you a
professional, studio -quality 101/2 -inch
reel deck at prices that compare favorably
with what you might expect from old
fashioned 7 -inch reel units. In our
judgment the old ideas must move aside
for the new ideas. And Pioneer has some
very intelligent new ideas in tape for you.
The convenience of cassette.
The performance of open -reel.
The new CT -9191, with built-in Dolby*
establishes a new and incomparable level
for cassette deck performance and
features. Designed with up -front controls
and cassette loading, you can stack other
components above it or under it.
Performance features stack up, too.
Bias and equalization switches insure
optimum recording and playback for every
type of cassette tape made. There's even
automatic bias/equalization switching
when the new type Cr02 cassette,
equipped with the special identifying
notch, is inserted. A front panel indicator
light signals this automatic operation.
memory index markers. In addition, there
are soft -touch solenoid operated transport
controls. This combination makes the 9191
the recording studio that fits on a shelf.
Two independent drive motors, plus
solid ferrite record/playback heads
combine to provide a new low in wow and
flutter (0.07% WRMS) and a new high in
ON
RESET
Simple vertical cassette insertion
visible at all times.
Distortion- and interference -free
recordings are consistently produced,
thanks to a combination of wide -scale
range VU level meters (-40dB to-{-5dB), an
LED peak level indicator light, a
selectable level limiter circuit, and an FM
multiplex filter switch.
Locating a desired program point in
a cassette is simple with the new CT -9191.
A specially designed memory rewind
switch (including record/play automatic
re -start) and 3 -digit tape counter, make
precision cueing a breeze.
Operation is further simplified with
automatic tape-end stop. dual concentric
rotary mic and line input controls for
mic and line mixing
and separate rotary
output level controls, all with adjustable
-
www.americanradiohistory.com
-
MEMORY
STOP/PLAY
o
oFF
Memory rewind with record/play
automatic re -start.
frequency response (20 to 17,000 Hz;
Cr02 tape).
Whether you choose the ultra
sophistication of the CT -9191 or Pioneer's
other front loaders CT -7171, CT -6161,
CT -2121, or the top loading CT -5151
and CT-4141A, which snare many
of its features, you're assured optimum
performance and maximum value in their
respective price ranges. One tradition that
never changes at Pioneer.
-
Open -reel. A professional
recording studio in your home.
Professionalism comes with all four
studio -quality open-reel models. The
RT -1020L (71/2, 33/4 ips) is unequalled in
Whether you
use a
cassette or
open reel deck
is up to you.
www.americanradiohistory.com
PIONEER
I
PIONEER
PIONEER
_..
...
1
PIONEEl2
RT -1020L
RT -1011L
qi:,}eHce
CT -4141A
www.americanradiohistory.com
RESIDUE
PROOF
Every record cleaner claims to remove
dirt. But you never read about what
stays behind. This omission may
be more than just oversight. See for
yourself.
--
Audi
August, 1975
"Succesor to RAQ,Q Est. 1917"
gill
7
Feature Articles
500% or Greater Residue
than
Vol. 60, No.
400%
A.N. Thiele: Sage of Vented
Speakers/Ray J. Newman
38 Audio Crossword
Motional Feedback in Loudspeakers/
George W. Tillet
30
40
300%
Equipment Profiles
JVC 4VR-542X Receiver
Wollensak 8080 Cassette Deck
47
52
56
Yamaha B-1 Power Amplifier,
UC -1 Control Unit
62 ELAC 760 Automatic Turntable
63 Sylvania AS -210A Speaker System
Bang & Olufsen
67
69
Addendum:
SAE
BE -220
Cassette Deck
MK-IIICM Amplifier
Record & Tape Reviews
JyP
zeU\S
«,
70 The Column/Fred DeVan
Canby's Capsules/Edward Tatnall Canby
Classical Reviews/Edward Tatnall Canby
,i-
QQP
zQ
80
82
Actual dry weight measurements of best selling record cleaners.
93
94
But this is just half our story. Only
discwasher's directional pile brush
(Pat. Pending) lifts fluid and residue
off the record by capillary action.
87 Jazz & Blues
Tape & Turntable/Bert Whyte
Theater Music/Donald M. Spoto
Audio in General
6
So things aren't left to air dry.
10
Discwasher-the superior record
14
16
cleaner is at Audio Specialists world
wide.
Audioclinic/Joseph Giovanelli
Tape Guide/Herman Burstein
Audio ETC/Edward Tatnall Canby
Behind the Scenes/Bert Whyte
20 What's New in Audio
22 Dear Editor:
74 Advertising Index
95 Classified Advertising
EDITOR Eugene Pitts Ill
PUBLISHER Jay L. Butler
ASSOCIATE EDITOR Edward Tatnall Canby
MARKETING DIRECTOR Sanford L. Cahn
ASSOCIATE EDITOR Bert Whyte
DESIGN Janet Lee
ASSISTANT EDITOR Charles Graham
CIRCULATION MANAGER Jean Davis
ADVERTISING PRODUCTION Evelena Brown
Contributing Editors: Herman Burstein, Martin Clifford, Fred De Van, Leonard Feldman,
Martha Sanders Gilmore, Joseph Giovanelli, Richard C. Heyser, Bascom H. King, C.G.
McProud, B.V. Pisha, Donald M. Spoto, George W. Tillett.
is published monthly by North American Publishing Co., Irvin J. Borowsky, President;
Butler, Vice Presidents; R. Kenneth Baxter, Vice President/Production: Nate Rosenblatt, Promotion
AUDIO (title registerd U.S. Pat. Off.)
Frank Nemeyer, and Jay
L.
Director; Mary Claffey, Circulation Director.
RATES-United States only: 1 year for $7.00, 2 years for $12.00, 3 years for $17.00; outside the U.S.: 1 year for $9.00, 2 years for
$16.00, and 3 years for $23.00. Printed in U.S.A. at Columbus, Ohio. All rights reserved. Entire contents copyrighted 1975 by
North American Publishing Co. Second class postage paid at Philadelphia, Pa. and additional mailing office. Back issues, $2.00
each. World Library Congress number: ISSN 0004-752X. Dewey Decimal number: 621.381 or 778.5.
REGIONAL SALES OFFICES: Jay L. Butler, Publisher and Sanford L. Cahn, Marketing Director, 41 East 42nd St., New York, N.Y.
10017, telephone (212) 687-8924.
lay Martin, 2525 West 8th St., Los Angeles, California, 90057, telephone (213) 385-2917.
REPRESENTATIVES: Continental Europe: John Ashcraft, 12 Bear St., Leicester -Square, London W.C.2, telephone 930-0525.
For Benelux and Germany. W.J.M. Saunders, Mgr., Herengracht 365. Amsterdam, Holland, telephone 24.09.08.
Japan: Japan Printing News Co., Ltd., No. 13.2 Chome Ginza Higasi, Chuo-ku, Tokyo, telephone 541-5795.
AUDIO Editorial and Publishing Offices,
134 N. 13th St., Philadelphia, Penna. 19107
Postmaster: Send Form 3579 to the above address
Discwasher INC.
909 University, Columbia, Mo. 65201
www.americanradiohistory.com
These four major developments
make the IHIC VENTURI speakers totally
u f n I i ke a l l others... and better.
u
BIC VENTURI Principle Bass
Section (pat. pend. ) transforms the
magnitude of air mass and energy in a
way never before applied to acoustics.
(Fig. A) The result is bass response
hundreds percent more
efficient and substantially
purer in quality than is
possible from any other
speaker of comparable size.
e
1uÁii\\\0\
B
-
B
Shows output of low frequency driver
when driven at a freq. of 22 Hz. Sound
pressure reading, 90 dB. Note poor wave-
Extended Musical Dynamic
Range results from the unique
combination of high efficiency and
high -power handling capability.
Even our smallest model, the new
Formula 1 can be used with amplifiers rated up to 50 watts RMS per
channel. The Formula 2 will handle
75 watts; the Formula 4, 100
watts; the Formula 6 can take 125
watts. Yet any of these can make
Titans of low -powered amplifiers.
A 4 -page color brochure is
needed, at the very least, to properly describe what makes these
DEC VENTURI speaker systems
so different, and we think you'll
agree, better. So this is what we will
send you, upon request. Or better
Biconex Pyramidal Dispersion form.
BIC VENTURI coupled
- Output
Horn (pat. pend. ) was developed duct,
(under the same conditions
Sound pressure reading 111.5 dB
to match the demanding capabili- (140 times output than
-distorted appearance.
ties of the BIC VENTURI bass
section. It is far more efficient, can
handle more power and covers a
wider, uninterrupted frequency
range than cones and domes.
And, unlike other horn designs, it
still, visit your BIC VENTURI
Biconez horn
can't add metallic sound colordealer, and hear for yourself.
ation and has truly wide angle
dispersion in both the horizontal
eo®
and vertical planes, for unresBRITISH INDUSTRIES Co., Inc.
tricted system positioning.
Westbury, New York 11590
C
of
as Fig.
B)
Fig. B) Note
more
non
BIC VENTURÌ
Dynamic Tonal Balance
Compensation (pat. pend. ) adjusts
speaker performance automatically
(when desired) to provide aurally "flat"
response at all listening levels in accordance with the Fletcher-Munsen
hearing characteristics. This is accomplished in a manner which cannot be
achieved by amplifier loudness or contour controls.
Div. of Avnet, Inc., In Canada:
C. W. Pointon, Ltd.
B.I.0 VENTURI
Check No.
9
is a
trademark of British Industries Co
on Reader Service Card
www.americanradiohistory.com
www.americanradiohistory.com
Our new series is
so advanced,we expect our
irrst customers to be
Audio Research & Crown.
They'll haul it back to their labs.
And play it. And play with it. And in
general, examine it to pieces to find
out How We Did lt.
Sony's Vertical Field Effect
Transistors: What our
competitors are eating their
hearts out about.
It's a shame the term "state of the
art" has been worn ragged in dozens
of "This is It, this is finally and really
It" stereoads. Because anyone in the
businesswil tell you that V-FET's are
the biggest thing since the invention
of thevacuumtube. V-FET's combine
all of the advantages of both triode
vacuum tubes and conventional
transistors. With none of their dis-
So much for the good points of
tubes. They also tend to be inefficient, begin to deteriorate as soon as
you use them, and wear out. Their
high impedance characteristics general ly require an output transformer
to drive the speakers. And there's no
way you can set up a true complementary circuit with vacuum tubes,
so there's no way you can get true
wave form symmetry.
I
advantages.
But nobody else can take advantage of these advantagesyet. Ask
anybody else how their V-FET's are
coming. The responses will range
from a forthright and candid "we're
working on it," to an equally forthright and candid "buzz off" Sony is
the first company in the world making commercially available equipment with V-FET's. A power -amp and
integrated amp.
Herewith a partial and oversimplified explanation of just what
in the world we're talking about.
,
Triode vacuum tubes:
Pros and cons.
To belabor the obvious for a
moment, in amplifiers, the name of
thegame is distortion. And until now
triode vacuum tubes have yielded
the lowest levels around. That's because of their non -saturating voltage
versus current characteristics. Also,
they do not suffer from carrier storage effect (which is standard equipment with regular transistors, and
causes notch distortion and deterioration in transient response).
©1975 Sony Corp.of America. Sony, 9 W. 57 St., N.Y.,
N V.
Harmonic distortion components.
Conventional Transistor
of the past.
Transistor switching lag.
The wave of the
future.
The lack of lag with V-FET's.
One reason nearly everyone will be
switching to V-FET's.
Conventional Bi -polar
transistors: Pros and cons.
The advantages of bi -polar transistors can be dealt with in a sentence. They're very reliable, very
efficient and last almost forever.
But there are a number of bugs in
the ointment.
Bi -polar transistors can become
saturated with current. And they all
cause switching lag distortion. To
obtain acceptably low levels of distortion, plus wide frequency response, you need to pump in a lot of
negative feedback. Which can make
the amp unstable.
Plus (at no extra charge), as they
heat up, bi -polar transistors have a
10019. SONY is
a
trademark of Sony Corp.
narked tendency toward thermal
runaway (which is a fancy way of
saying they try to self-destruct).
V-FET's: All pros. And that's
no con.
First off, V-FET's are very reliable, very efficient and last almost.
forever. They.also match the highly
defined tonal quality previously provided only by vacuum tubes. V-FET's
don't becomesaturated with current.
But at the same time, they protect
themselves as temperatures build
up. So there's no potsibility of thermal runaway. Their low impedance
characteristics mean no output
transformer (the less gizmos in the
circuit, the better the sound). The
use of V-FET's allows for better control of negative feedback, making
the amp more stable. V-FET's don't
have carrier storage effect to cause
switching lag. And you can use
V-FET's to build a true complementary circuit, thus obtaining true.
wave form symmetry. And isn't that
what it's really all about?
One morething. We'd be less than
forthright and candid if we didn't
admit that our new amplifiers are a
bit pricey. As much as $1300 a piece.
At Sony, we've always maintained that, in the end, the best way
to buy equipment is to hear it for
yourself. So we're making what's
probably the best offer you've ever
heard. Have your dealer hook up our
new V-FET equipment against anything made by anybody. If we sound
sure of ourselves, we are.
And we'resureyourownearswill
tell you we've got the best sound
you've ever heard.
'
SONY
Check No. 34 on Reader Service Card
Audioclinic
J
Joseph Giovanelli
"Stuck" Stylus
Q. After balancing the tonearm,
setting the tracking force for 2 grams
(required by my cartridge), and setting the anti -skating force for that
same 2 grams, and making sure that
the cartridge is adjusted properly for
overhang, put on a record. All went
well until the arm was about an inch
and a quarter into the record, the stylus then gets "stuck." This happens on
ALL of my records, new and old.
found that I could move the arm
slightly inward, and once again, all
goes well for a time. When the arm
reaches four and a half inches in, it
once again "sticks." I have tried
mounting and remounting my cartridge. I've changed the tracking force
to 1.5 grams, using both antiskating
settings for conical and elliptical. My
tonearm still "gets stuck." know that
this is not a problem related to worn
or dirty records because it occurs with
all of my records.
I hope the problem is that I am
doing something wrong and not my
turntable. Your advice will surely be
of help.-R. Padilla, New York, N.Y.
A. suggest that you obtain a force
gauge. Use it to check the accuracy of
your tracking adjustments. Sometimes the calibrations for tracking
force are incorrect, and this can only
be determined by the use of an independent tracking force gauge. Like
the tracking force adjustments, the
antiskating force calibrations could be
incorrect, so that you are using too
much antiskating force. To obtain a
reasonably good setting, consider obtaining a blank disc (one having no
grooves at all) from a recording
studio. Set the antiskating force so
that the arm moves neither inward
nor outward. Move it to various
points on the surface of the disc. You
may have to compromise on this adjustment. In some parts of the disc the
arm will tend to pull inward slightly;
in other parts, it may pull outward by
an equal amount.
Your problem also could be the result of defective bearings. They may
have so much friction that the arm is
1
1
1
I
not free to be pulled along by the stylus. In that case, the turntable should
be returned to your dealer for repair
or replacement.
Paralleling Speakers
Q. My receiver puts out 70 watts at
ohms and 90 watts at 4 ohms. There
provision for two sets of speakers on
this receiver. Does this mean that my
resistance is 4 or 8 ohms? I am using
four 8 -ohm speakers.-Mark Smith,
East Hanover, N.J.
A. First you should understand that
speakers are rated as to impedance,
not resistance. It's easy to confuse
these two related, but different
things. The term impedance takes into
account both resistance (which is the
same regardless of frequency) and inductance (which changes with frequency).
The switch on the front panel of
your amplifier selects Main, Remote,
or both Main and Remote (together).
It is not intended to select the impedance presented to the amplifier.
When both the Main and Remote
speakers are operated at the same
time, the speakers are wired in parallel. Thus, in your case, you would
have two 8 -ohms speakers in parallel
on each channel, resulting in an impedance of 4 ohms. Do not add more
speakers in parallel. To do so might
well result in such low combined impedance (two ohms or less) that your
amplifier would be damaged.
8
is
ver, is acting as an amplifier, just as
you have said. Probably there is a
playback correction network in that
amplifier, which accounts for the
added bass.
Your receiver does not produce
more power when the tape deck
amplifier drives it. The power amplifier can deliver only so much power. A
preamplifier can only boost the input
voltage feeding the power amplifier.
When the voltage reaches the point at
which the amplifier is delivering its
rated power, no additional increase
can take place. Increasing the signal
input voltage further can only produce distortion and possible damage
to the amplifier's output stage.
There are also preamplifiers which
are incorrectly called "power boosters." These preamplifiers amplify the
output of musical instruments such as
electrical guitars. They do not add
power. They boost the signal to the
point where it can drive the power
amplifier to obtain its maximum rated
power.
Wiring a Cartridge for Mono
Q. In some phono cartridge installation instructions, the user is directed to join the left and right channel
leads, either at the cartridge or at the
preamplifier for monophonic service.
Might this practice not upset the
cartridge loading characteristics or
spoil the response in some other
way?-(Name Withheld), Los Ange-
More Power From an Amplifier?
les, Cal.
have a Lafayette 8 -track recorder. I have found that I can run the
FM portion of my receiver through
the deck. With the tape switch on, I
notice a tremendous increase in bass
and I also notice a considerable increase in volume. What I think is happening is that the tape deck is used as
an amplifier. Please give me an estimate of the increase in power that I
A. Wiring a cartridge for monophonic service in the manner described in the instruction manual will
change the recommended optimum
load. The actual, audible effect of
such a change will ordinarily be of so
little consequence that it is ignored.
Q.
I
can expect from this arrangement.-Mark Smith, East Hanover,
N.J.
A. Your tape machine, when used
If you have a problem or question on audio, write to
Mr. Joseph Giovanelli, at AUDIO, 134 North
Thirteenth Street, Philadelphia, Pa. 19107. All letters
are answered. Please enclose a stamped, selfaddressed envelope.
to alter the sound from your recei-
AUDIO AUGUST,
6
www.americanradiohistory.com
1975
THE INNOVATORS.
BY BOSE.
The only Direct/Reflecting loudspeaker systems.
The Bose 901, 501 and Model 301. The only speaker systems that meet the two basic requirements for
preserving the qualities of live music in reproduced
sound: the proper balance of reflected drid direct
sound for spaciousness and clarity; and flat power
radiation to assure correct frequency balance and
accurate reproduction of instrumental timbre in an
actual listening environment.
The internationally acclaimed 901 system util-
izing nine full range drivers with an active equalizer
to provide the ideal balance of reflected to direct
sound at all frequencies, setting the standard for
lifelike music reproduction in ire home.
The new Model 301 offering a unique combination of features: Asymmetrical Design, a Direct
Energy Control and a Dual Frequency Crossover'
network. This achieves reflected and direct sound
with flat power radiation in a bookshelf enclosure,
producing a sound quality that is extraordinary
from so compact a speaker at so low a price.
The innovative speakers. From Bose. Each unique
in concept and design to provide the maximum
musical enjoyment for your home. One of them
will ideally meet your requirements.
Shown above, left to right, 501, 901, and Model 301.
For information, write to us at room AS.
The uncon entional 501 incaürporating an exceptionally linear 10" woofer and two rearward facing
tweeters to furnish many of the performance advantages of the 901 system, but at substantially lower
cost.
.Yodel 301 Patents :'ssued and Pendir g
The Mountain, Framing'` -am, MA 0170;
Frequency response and distortion
are substantially unchanged. Distortion is probably a bit less because of
the cancellation of the vertical component caused by the "pinch effect."
Turntable Cueing Revisited
In the December, 1974 issue of
Audio you described one way to cue
up turntables. can suggest another,
simpler method which I've used for
several years to produce top-quality
tapes, using only a reel-to-reel tape
deck, two turntables, two Shure pre -
amps, and
a
Crown IC -150 preampli-
fier/control unit. Here's how it works:
1. Plug outputs from arm into Shure
stereo preamps.
2. Plug output from preamplifiers
into the two tape inputs on the pre-
amplifier.
3. To play each table: turn the IC 150 function selector to Tape 1 or
Tape
4.
1
2.
To cue each table: push Tape
Monitor
1
or Tape Monitor
2.
As you can appreciate, when the
monitor
is depressed, there is no
effect on the Line outputs feeding any
connected tape machines. However,
the main outputs feeding the power
amps now carry the cue information.
Further, any adjustment in cue volume has no effect on the line outputs. When the monitor function is
released, the straight program material is still available.
The separation between the line
and monitor functions in the IC -150 is
around 75 dB, more than enough for
this scheme to work well. This scheme
will work with any preamplifier or integrated amplifier having two tape inputs and two tape monitors.
True, with this system, no segue is
possible. In such a situation, I use
another approach. At my studio, we
have a Sony MX -16 mixer. It is set up
so that, at the bottom of each slide pot fader, a micro -switch switches the
output of the phono preamplifier
from the mixer input to a pair of
(added) stereo output jacks, which are
then connected to a cue amp. Each
slide -pot on this mixer has been
equipped with its own micro -switch
so that all signal sources can be cued.
Multi -source montages are easy to
accomplish. This micro -switch idea
could be used just as easily with any
small, straight-line mixer, such as a
Sony MX -12, Telefunken, etc.
By adding a switch to the pots on
mixers equipped with rotary pots
(Shure, etc.); these mixers can be
used for cueing. In other words, when
any pot is turned off, it is placed automatically into cue! Works well, too!
-Stephen H. Lampen, San Francisco,
CA.
The critical acclaim
has peen as impressive
as the orocuct
itself,
These nc e aenc ent
test la °oratory reviews
i
and these supero
stereo comoonents are
now reacily available.
RSVP
America
7733 Telegraph Road, Montebello, California 90640
Note. I hope that you find this sort
of material interesting and helpful.
Those readers who are kind enough
to take the time to write up this sort of
information are specialists in their
fields, and, as such, are privy to
knowledge not normally available to
most of us.
So for myself and the rest of my
readers, thanks to all of those who
have written, and to those who will do
so in
I
the future.
will be especially glad to hear
from any one out there who has had
success dealing with line transients. I
refer to those instances where a refrigerator, fish tank, oil burner, etc.,
puts a pulse on the power line, which,
in turn, finds its way into a music system and produces audible pops or
other noise from the loudspeakers.
Some equipment is more sensitive to
this than others. While this sort of interference can often be eliminated by
placing a constant voltage transformer between the power line and
the music system, this is an expensive
cure.
TEAC Corporation of
www.americanradiohistory.com
8
AUDIO AUGUST,
1975
The tuner that restates
the state of the art.
Imagine a stereo FM tuner that performs as
cleanly and vividly as your favorite records. That
has distortion so low it defies laboratory
measurement. That automatically rejects all
unwanted noise and interference.
You're looking at it. The YAMAHA CT-7000...
the new state of the art tuner. Its cost? $1,200.
So listen at your own risk, because you may
never be satisfied with any other tuner again.
It's the first tuner with Negative Feedback.
Long used in amplifiers to lower distortion, the
application of Negative Feedback to the CT -7000
has all but eliminated MPX distortion. (At 400 Hz,
for example, it's an unheard of 0.02%-and that
includes distortion caused by the measuring
instrument itself.) Also, Negative Feedback
eliminates the need for distortion -causing Side
Carrier Filters.
For superior separation of the left and right
channels, Yamaha designed a unique Phase Lock
Loop MPX Decoder Instead of being a single IC
chip as in other tuners, our Phase Lock Loop
consists of discrete components mounted on
their own circuit board, thus allowing precise
control in production and hand -tuning adjustment
to meet exact specifications.
A 7 -Gang Tuning Capacitor? Most tuners get
by with 4 or 5 stages. We refused to. By
designing the Front End with our unique 7 -Gang
Tuning Capacitor and utilizing Dual Gate MOS
FETs, the CT -7000 can receive the weakest
stations and, at the same time, accept an
extremely high input (up to 1 volt input signal)
without overloading.
Advanced IF Amp Stages. Inside the
IF
amp
stage is the world's finest combination of ceramic
and L/C filters. This has resulted in an advanced
degree of selectivity (the ability to pick out a
desired signal while rejecting neighboring
frequencies). And maintains proper phase
linearity and minimum distortion (less than
0.08%).
A selectable IF Mode lets you choose the
width of the tuner's selectivity...narrow setting
for crowded band areas; wide setting for
uncrowded areas. The tuner's reception can be
optimized for virtually every listening situation.
Some other important differences. An Auto
B/end Logic Circuit automatically operates in
three stages to blend high and middle -high
frequencies for maximum stereo separation with
minimum noise and distortion on even the
weakest stations. And you don't need to get up
and switch in the MPX filter when a station turns
noisy. The CT -7000 does it for you-silently,
automatically.
There's Auto -Touch Tuning that automatically
disengages AFC while you tune, for maximum
station selection. When you release the tuning
knob, AFC reengages and locks onto the station,
electronically fine-tuning it to the one point of
maximum stereo separation and minimum
distortion.
A unique Variable Muting Control makes it
possible to receive music where there used to be
just noise. This control lets you select the muting
cut-off level to an unbelievably low 10 dB (3 mµ),
yet it can be adjusted to accommodate stations
up to 30 dB (30 mµ) in level.
Variable Output Level permits adjustment of
the tuner's output to match the other input levels.
So, when switching from tape, to records, to the
CT-7000, you don't have to readjust your
volume control.
The end of Multipath Distortion. Reflection
of
FM signals off their surroundings causes
multipath distortion. And that causes muddled,
distorted sound. Until now, you could rely on
inaccurate signal strength meters to orient the
antenna-or you could invest about 800 dollars
in an external oscilloscope.
The CT -7000 neatly solved that problem with
unique signal minus multipath circuit which
when activated by the S -M front panel relay,
allows the signal strength meter to accurately
display the multipath content of the incoming
signal. Without guesswork, you now can zero -in
the antenna incoming signal to reduce to a
minimum multipath interference and distortion. In
a
fact, tests show the S -M meter of the CT -7000 to
be three times more accurate for this purpose
than an oscilloscope.
Some things we didn't have to do. We could
have settled for just having the best performing
tuner in the world. But we also wanted it to be
the most reliable and durable.
That's why all the push buttons are silky smooth, precision reed relays instead of switches.
Why the flywheel is solid brass. And why, beneath
the walnut wood case, each circuit board is
protected by a stainless steel cover to guard
against stray noises and interference.
Or as Stereo Review summed it up in its
January 1975 issue: "Judged by its overall
measured performance, the Yamaha CT -7000 is
clearly one of the finest FM Tuners ever made. In
no respect was it less than superb, and in a few
areas-notably distortion, image rejection. AM
rejection, and pilot-carrier suppression-it was
either far better than anything we had previously
measured or simply beyond the measurement
abilities of the best laboratory instruments"
Your Yamaha Audio Dealer will be pleased to
demonstrate the incomparable CT -7000. Plus
other state of the art Yamaha components that
make up the system-designed to make you
unhappy with what you're listening to now.
Because, like life, the best is always yet to come.
YAMAHA
INTERNATIONAL CORPORATION, P.O. BOX 6600. BUENA PARK, CA 90620
Check No. 39 on Reader Service Card
www.americanradiohistory.com
Tape Guide
Herman Burstein
Tape Head Care
Q. I am writing to you in the hope
that you will be able to answer questions that my dealer can't. I am the
proud owner of a Revox A-77 deck.
The manual supplied with the machine is very comprehensive, but it
makes no mention of routine head
and guide demagnetization. Is such
maintenance required for the A-77?
Also, my machine is set up for Scotch
203 tape. Will the use of a thicker base
tape (11/2 mil Scotch 202) cause any
significant increase in head
wear?-Peter A. Thrift, Bellevue, Nebraska
A. Manufacturers often recommend that heads and guides be
demagnetized after about every eight
hours of use. On the other hand, at
least one manufacturer recommends
much less frequent demagnetization.
If you want to be on the safe side, I
suggest that you write to Revox.
doubt that there will be significant difference in head wear according to the thickness of the tape. More
important is the quality of the tape
you use. One that is optimally lubricated and that doesn't shed excessively is best. Tape tension and
pressure exerted by pressure pads (is
used) also affect in head wear.
I
Which Tape Deck to Buy?
Q. I am trying to decide which tape
deck to buy. I want no compromises. I
want it to have 101/z -in. reels, three
motors, solenoid operation, automatic stop at predetermined places,
auto -reverse, smooth handling, 15,
71/2, and 33/4 ips speeds. I have read
that the only difference between a
quarter -track and a half-track recording is about 3 -dB better signal-tonoise ratio. Is this true, and how much
difference does 3 dB make?
I have read a lot about the Dolby
system and wonder if it would provide much improvement on a topquality recorder? I am listing the ma 10
chines I am considering. Please tell
me which are the best, and also what
tapes are the best.-John Nuss, Old
Bethpage, N.Y.
A. I cannot make recommendations as to the best machine for your
needs. As I have stated here previously, Audio's policy prevents me
from doing so. Considering the high
standards you are setting for yourself
and the considerable amount of
money you will be spending, I believe you should take the time to get
out to the audio stores to check with
your eyes and ears the performance
of the machines which interest you.
A 3 dB difference in signal-to-noise
ratio is significant, but barely so. In
other words, it would be slightly audible. With fine tape machines such
as those you list
doubt that Dolby
would make much difference audibly, unless you go down to the slowest speeds. Dolby makes the most improvement with machines which have
poor S/N ratio to begin with.
I
Or you can use an
audio oscillator connected to a power
amplifier and vary the sine wave output of the power amplifier, using it to
supply the a.c. power for your playback tape machine. Of course, the
machine you make the new recordings on will use regular a.c. power.
ics magazines.
Recording Whistle
Q. For years I have been recording
off the air with an Eico RP100 recorder and a Scott 350B tuner with satis-
factory results. I recently acquired a
new tuner, Kenwood KT6000, and
with the same recorder I now get a
continuous high frequency whistle
along with the program material. I am
told this is due to interaction of the
bias oscillator of the recorder (50-100
kHz) with the pilot tone (38 kHz) that
is part of all stereo broadcast signals.
How can this be corrected?-Stephen
Gaydica, Hewlett, N.Y.
A. The reason you have been given
probably correct. The solution is to
introduce a tunable filter between the
tuner and the tape recorder. suggest that you consult your local audio
store, a mail order audio house or the
makers of your equipment.
is
I
Correcting Wandering Tape
Speed
Q. When
I
listen to
a
tape from my
a small,
mother made in 1964 on
cheap reel -type "voice
letter"
machine, the speed varies throughout the tape, and her voice runs from
a squeaky high to a low bass. I have
dozens of tapes kept over the years,
some with voices that no longer exist,
and others which can never be
duplicated. All contain some speed
variations. Is any equipment available
that I can use to correct the speed of
these tapes while make new, even speed copes of them?-J.R. Kendrick, Honolulu, Hawaii
A. The only solution is to vary the
frequency of the a.c. power to which
you connect your tape machine. You
can build such a power supply from
construction articles which have appeared from time to time in electron-
Recording Level Problems
Q. I am recording with a TEAC A15000 tape deck. I set the monitor
switch to Source and adjust the level
so that the VU meter reads 0 on the
loudest passages. When the tape is
played back, the level is too low (hiss
audible), and peak passages register only -4 or -5 on the VU meter. I
is
1
a problem or question on tape recording,
write to Mr. Herman Burstein at AUDIO, 134 North
Thirteenth Street, Philadelphia, Pa. 19107. All letters
are answered. Please enclose a stamped, selfaddressed envelope.
If you have
AUDIO
AUGUST, 1975
The exceptional sound quality and high power of
Dynaco's Stereo 400 places
it in a class by itself. Now we
have designed the Dynaco
Stereo 150, for those who
want the sonics of the 400
with more modest power.
Within its power rating, the difference is almost undetectable.
Like the 400, the Stereo 150 offers a massive
power supply, full complementary symmetry
output, and thermal tracking bias to eliminate
'notch" distortion. Pre -tested audio circuitry
and wide open layout make it a typically
easy Dynakit to build.
Combine it with our new PAT-S-already famous
for the very finest solid state sound.
Even on a cost -no -object basis,
you still may not
believe your ears.
ti
PAT -5 Ki+ $199; Assembled $325
Stereo 150 Kit $225; Assembled $325
Stereo 400 Kit $499; Assembled $669
MINIMUM POWER OUTPUT SPECIFICATIONS
Maximum total harmonic distortion less than 0.25% from 20
Hz to 20 kHz into an 8 ohm load, both channels driven, with
Stereo 400-200 watts per channel
FTC preconditioning:
Stereo 150-75 watts per channel
www.americanradiohistory.com
IvacOBlackwood, N. J. 08012
Also available .n Canada from Dynaco of Canada Ltd.
f yo ore considering
on investment in
reprodLctio,
have played my tapes on another
deck (Sony 255) and get the same low
playback level. But a tape recorded on
the Sony plays back properly on the
TEAC. I am using Scotch 290 (1/2 mil)
sod
tape.-John
Don't make a move
until you hear
the 3 new BOZAKS
For more than 25 years Bozak has been provid-
ing discriminating music listeners with loudspeakers which have been recognized as representing the highest standards of integrity in
sound reproduction.
Now Bozak has applied its same principles of
Model 919 Audio Signal
-
pushing the limits of the state of
the art without compromising the laws of
science
to two new electronic products and
design
a
new monitor type speaker for the home
music systems of those who recognize and
demand "the very best in music."
found in commercial sound studios. With it you can
mix and blend stereo sounds from records, tapes,
tuners and microphones with differing input levels
into a two -channel composite for recording or for
listening.
929Audio
Power Amplifier
ultimate in an amplifier for the home music
system, the Model 929 has nearly identical circuitry
to Bozak's commercial Model CMA-2-150 which has
been selected for the most demanding applications
The
in concert halls, theaters and
auditoriums. Each of
its two channels delivers 150 watts continuous
minimum sine wave power into 8 ohms from 20 to
20,000 Hz at less than 0.2% total harmonic distortion. That is enough power for even the most impor-
tant home music systems
-
those employing
Bozak's Concert Grand speakers.
Monitor C
Loudspeaker System
Monitor C has been specifically designed to reproduce modern music, with its heavy emphasis on
bass, with the greatest realism possible. You truly
hear each note as it was played; Monitor C spells an
end to "thump-thump" bass. Discotheques, as well
as homes, are taking it to their hearts.
You can hear these magnificent audio system components at selected Bozak dealers. We'll gladly send
you the name of one in your area.
egeg
Bozak, Inc.
Box 1166, Darien,
Bagwell,
Lanham,
A. It appears that your problem is
miscalibration of the VU meter. Whether this is true for tape in general, or
only when you use 1/2 mil tape, can
easily be checked by investing in a
small reel of 11/2 or 1 mil tape and
noting whether you still get underrecording. It is also possible that your
machine is underbiased. Up to a point
more bias current increases the
amount of signal that gets recorded
on the tape. If treble response is
exaggerated, which can happen when
there is too little bias, then under -
biasing
is
indicated. Have
an
authorized technician check the bias
and record/play response.
Concert Hall Recording
Processing Center
This mixer -preamplifier gives much of the flexibility
Model
L.
Maryland.
Connecticut 06820
Q. have the fantastic opportunity
of recording live in the Teatro Colon,
in Buenos Aires, one of the best con1
cert halls in the world. The Teatro
Colon, however, does not encourage
recording engineers, and its equipment is painfully obsolete. I must get
acquainted with modern equipment
and techniques for recording live, but
none of the magazines to which l am a
regular subscriber offers much information on recording techniques and
equipment. Would you know of any
publication (books, manuals, magazines, catalogues, anything!) that
could give me not -too -technical
reports on available recording equipment and general information about
recording techniques?-Oscar
12
www.americanradiohistory.com
J.
Romero, Buenos Aires, Argentina
A. You might write directly to
manufacturers of recording equipment. You can get their names and
addresses from Audio and other
periodicals in which they advertise.
Audio published a series of three
articles by David Josephson on Microphones in December, 1973, July
and Aug. 1974. You will find a chapter
on microphones in Hi-Fi Made Easy
by Norman Crowhurst (Gernsback Library, 154 W. 14th St., New York,
N.Y.). A chapter on microphones is in
my book, Getting the Most Out Of
Your Tape Recorder (John F. Rider,
Inc., 114 W. 14th St., New York, N.Y.)A
chapter on using a tape recorder and
microphones ("Increase Your Enjoyment of Music") is in How To Select
and Use Your Tape Recorder by David
Mark (Rider). And a chapter on stereo
microphone technique is in my book
Stereo, How It Works (Gernsback).
AUDIO
AUGUST, 1975
The Final buc oF
cxcellencJc to o
oonb oot...,lnc oyot.C!rY1
ouoonb
KENWOCD introduces with pride the incomparable
Model 7 and the new LS -Series Speaker Systems.
Not since the invention of the loudspeaker itself
has there beef such an exciting breakthrough
in high-fidelity sound reorodact>on!
LS -40F
e<cepticgh-
Model 7
7... uncompromising performance
that rec-eates an exact replica of original sound.
Uniquely fabricated diaphragms Powerful new
magnetic assemblies Special lu aber -core
baffle board 4 -way system with ^_nique
d.viding network.
The LS -Series .. three
ef'iciency speE ker syst-aens that aut advance J
sneaker design and pe fxmanc a wit in rance
of a moderate budget.
The Model
For
complete information, write ...
KENWOOD
15'77
S.
72 02
Fiftyfrst
n
Broadway. Gardena, Ca 90248
A e., Woodside N.Y. 11277
Canada: Magnas+)nic Canada, Ltd.
Check No. 18 on Reader Se Mee Card
Audio ETC
0
Edward Tatnall Canby
lieve it. From the recessed couch (1), actually a bit behind
the back speakers, the effect is splendid though the left
channel is partially in acoustic shadow and the right is rather
close. Fortunately, the Interface: A speakers have excellent
sound dispersion, so that you must walk right up to one of
them before the sound is heard separately. Mark of a good
quadraphonic reproducer. From the center of the space (2),
can do my favorite walk -about listening, on foot. There's
just room to move in time to the music without bumping
into a channel. As for the day bed, it is sonically out of
bounds. don't listen in bed.
From my work desk in the semi -alcove near the entrance
door, hear a reversed image via reflection. By no stretch
could this be called discrete quadraphonic-but find it
pleasant even so, and better than it ever was in stereo from
the same place. More info, even if scrambled.
had long previously found that the placement of the
front (stereo) speakers at the edges of the flat overhead
arch, with space behind them, greatly enhanced the forward
sense of distance and fullness of sound as one listens from
the main part of the room. Now, that big space is drawn in
and around the back speakers to include the whole listening
area. could ask for no more.
As for the E -V Interface: A speakers, they did indeed fit
right into this arrangement. They are of a new, little shape,
only 14 by 22 inches and so shallow, only eight inches deep,
that you can back them inconspicuously near a wall at the
back of a table or other support where, with their neat black
grille covers, they blend right into th background, out of the
way. No need to make separate furniture lumps out of them.
CLOSET
PIANO
The units were designed as an updated, computer -calcu14-1
lated, optimum juggling of a number of ingeniously com(BACK)
bined principles for maximum bass in minimum space-an
COUCH
TABLE
--FLAT ARCH
honorable and ancient idea. Inside there is a tuned system
2
for efficiency (I noticed this immediately) and a passive (FRONT)
front radiator which, in effect, replaces a body of air larger
than the box could hold, for correspondingly -increased bass
EQPT.
range. Also, there is an equalizer unit, one (stereo) for each
ll
II
KITCHEN
pair of speakers. It adds 3 dB of bass boost, with a bottom
15_ DAY BED
cut-off to avoid rumble and shake.
N=7l
Now, I, along with plenty of other hi-fi people, have alSHELVES
ways distrusted electronic boosting of this sort. It is not the
thus worth the effort.
ideal way to get bass, which might be said to be the Klipsput the front speakers where, years ago, I had found the chorn way, for one. But corner Klipschorns do not into an
only workable location for stereo in that same addle -shaped apartment fit, especially one with 10 mini -corners like mine.
room. tried them all. You will note that the back speakers,
found that E -V's very modest 3 dB boost was gentle in aclike the front, occupy positions of approximate room sym- tion and introduced no audible musical problems for my
metry, in a highly lopsided area. It is a first principle that one ears. Moderation is a good principle.
never places pairs of speakers in grossly unsymmetrical locaOne problem, though not E -V's fault. The equalizer units,
tions-say, one with a wall or corner behind it and the other two for quadraphonic, must be inserted before the main
with a big space behind. It will not work. Don't even try. On amps and thus use the familiar record -out and monitor -in
the other hand, even a barely approximate symmetry, as be- system, through pairs of connecting cables. (There are extra
tween that small corner niche, where my right back speaker ins and outs to take your other equipment.) So for just plain
is (former telephone table location!), and the corner next to
phono, hooked in 10 signal cables and four power cords in
the kitchen, opposite, where the left speaker is, can work an unsightly mess of wire dangling oehind my equipment
out astonishingly well. The little niche made all the differ- table. Suppose were to add tape, plus Dolby, Burwen or
ence, as specifically found out.
dbx, plus an outboard demod or decode unit? All use in/out
For three positions, as marked, achieved a spacious and monitor jacks, and the wire tangle would be monstrous,
listenable quadraphonic sound, though you might not be- even dangerous. Aaargh!!!
,o+
N
THE THEORY that one diagram is
umn of words,
worth
a
col-
spent a lot of time recently on my
hands and knees in my New York apartment, taking
measurements-see diagram. There you will find my own
solution to a major problem these days, how to cram four
channels of sound into a crowded, ill -shaped urban apartment. Most people still think it is impracticable.
Far from it. In fact, it took me less time to find the right
place for four small speakers in my zany and unsymmetrical
apartment than it did to make the diagram, unaccustomed
as
am to public drawing. It is a sure thing, I say, that if we
don't get four channels into thousands of urban apartments
like this, we might as well give up, because urban America is
America, at least indoors.
For a long time, I've had a hunch that this problem wasn't
as bad as most people think. When Electro -Voice recently
turned up with a new small -space, big -bass speaker designed expressly for this type of situation, acted fast. borrowed four of the Interface: A units, which come in pairs,
and hauled a quadraphonic receiver down from the country
to plug them into. My four-way solution, as per picture,
came after a series of trials in various temporary positions-and hasten to add that you must do this first, before
you get into arguments about furniture and decor. Nine
times out of ten, there will be no need to do heavyweight
moving. Rather, it's likely to be a change of tables, pictures,
lamps, and chairs, no more. But the right place, you must
understand, is going to be vastly better than the wrong and
I
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0
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14
AUDIO
AUGUST, 1975
Bett. best. best buys.
Fact: the lowest cost way to improve your whole high fidelity system is
simply to upgrade the source op sound-the cartridge! If you're on a temporary austerity program, the Shure M44E can make a significant difference
in sound over the cartridges supplied with mane budget component systems.
If your budget is a trifle more flexible, an M91 ED can bring you into the area
of high trackability (with performance second only to the V-15 Type Ill). And
for those who can be satisfied with nothing less than state-of-the-art playback perfection, Shure offers the widely acclaimed V-15 Type Ill, the recognized number one cartridge in the industry, which, in '¢ruth, costs less than
a single middle-of-the-road loudspeaker. To lead about what a Shure cartridge could do for your system, write:
i`
Shure Brothers Inc.
222 Hartrey Ave., Evanston, IL 60204
In
Canada: A C. Simmonds
&
Sons Limiters
or«
SHIRE
Manufacturers of high fidelity components, microphones, sound systems and related circuitry.
Check No. 33 on Reader Service Card
www.americanradiohistory.com
Behind The Scenes
Bert
EVEN AS THE SWALLOWS
come back to Capistrano each
year, a bit further South in
California, the audio fraternity flocks
to the annual Los Angeles convention
of the Audio Engineering Society. This
51st convention of the AES was held
May 13th through 16th in its usual
place at the Los Angeles Hilton.
While the country in general and
certain sectors of the hi-fi industry are
still in the thrall of the recession, this
seems not to be the case with the
world of professional audio. The 51st
convention was decidedly upbeat,
with first day attendance breaking all
previous AES records, overall attendance setting a new record, and the
greatest number of manufacturers exhibiting products to date. While there
was some cautionary hedging about
business conditions from
a
few
people, in general, the atmosphere
was buoyant, confident, and optimistic.
However, it must be noted that
while there was plenty of new equipment on display, there was nothing
particularly outstanding or revolutionary. A good number of things
could be classified as evolutionary updates. In other words, this convention
gave us nothing on the order of the
BASF Unisette, or high polymer
piezoelectric films that were the highlights of recent conventions. Speaking
of the Unisette, it appears that its production timetable has gone awry once
again. The anticipated playback deck
from Studer has yet to be seen, and
similar decks from purportedly interested Japanese manufacturers have
not appeared either. Insiders say cost
is the problem, and with the inflation bloated prices of parts and supplies,
this is easy to understand. hope this
can be overcome, and soon, for in this
reporter's opinion, the Unisette has
great potential and a definite place in
the world of audio.
At this convention, as usual, when
one walks into the main exhibit area,
the eyes are assaulted by a vast panoply of professional products (how's
I
Whyte
that for alliteration!). Considering that
there are 15 other rooms or areas, plus
demo rooms on another floor, all
stuffed with audio equipment, one
hardly knows where to begin. It is im-
practical to cover everything...for
one thing you're constantly bumping
into people you know, and in no time
at all, five or six people are holding a
mini -seminar on some aspect of audio, meanwhile doing a damn good
job of blocking the aisles. Then you
meet those who suggest a brief hiatus
from the show to partake of a refreshment. Lastly, it must be admitted that
bypass some products which are of
little interest in my audio milieu. Thus,
with apologies to those who may feel
slighted, some random observations
on audio products that caught my eye
in my ramblings through the exhibit
I
halls.
Neve unit, called Kelso, is particularly
attractive and uses those super
smooth conductive -plastic faders.
The Dolby stand featured the new
CP100 Cinema Processor for the pro-
duction of Dolby -encoded magnetic
and optical sound tracks and-the
new sensation-stereo optical tracks.
Dolby was hosting a demonstration
film, incorporating encoded -stereo
optical tracks, at the Doheny Plaza
Theater, but unfortunately the theater
was located in Beverly Hills, quite a
haul from the Hilton in downtown
L.A., so did not get to the demo. Dolby has also gone into the noise production business, and Ray and Dagmar Dolby were proudly showing
their first model, five -month -old Master Thomas Dolby.
Attracted by a blinding light at one
booth, found it was Crown International lighting up 600 -watt bulbs with
their M600, a mono power amplifier.
If you have a speaker with a 4-ohm
impedance, connect it to this unit
which will pump out a mere kilowatt!
Amplifiers were much in evidence at
the convention as witness a new 400watt/channel unit from Altec, and
300-watt/channel units from JBL and
SAE. BGW was on hand with its "Senssurround" Earthquake amplifier, as
well as lesser power units. Up on the
fourth floor, Yamaha was getting
plenty of attention demonstrating its
new $1600 vertical FET amplifier, the
B-1. Its companion accessory module,
for comparing up to five pairs of
speakers, should find favor with the
high -end hi-fi shops.
At the Philips' booth and on demo
on the fourth floor, the new AKG
BX10 reverb unit was creating quite a
stir. About one quarter the size of the
BX20 unit am currently using, it features the same b000iinggg-free re verb of the big unit and at less than
half the price (approx. $1300.00).
Magnificent professional tape maI
I
You can always count on Steve
Temmer, of Gotham Audio, to come
up with an exotic product. This time it
was the Europa Film high-speed electroplating system for producing
record mothers and stampers. The
master lacquers are plated in two
kettle -shaped containers, and people
were kidding Steve that he had a fast
food franchise for "broasted" chicken! With racks of ancillary equipment
and interconnecting fancy plumbing,
the system fairly reeks of precision
and high technology. The unit uses 40
volt/400 ampere rectifiers (with a fuse
nearly as thick as my wrist!), and deposit time for a 10 -mil plating thickness is less than 30 minutes.
There is always a bewildering profusion of mixing consoles at any AES
convention, and each year they grow
more elaborate. There seems to be a
growing trend towards automatic programmed mixdown, wherein once
set, a particular mixdown can be repeated whenever desired. Consoles
from Automated Processes and Quad
Eight featured such facilities. As for
so-called portable mixers (transportable would probably be more accurate), there were legions of them, in
all sorts of configurations. The baby
16
I
chines were being displayed by such
as Ampex, Scully, 3M, MCI, and Studer, in various formats up to 24 channels on 2 -inch tape. There were no
AUDIO
www.americanradiohistory.com
AUGUST, 1975
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It features a unique "induced magnet"
whereby the magnet is fixed and the
magnetism is induced into a tiny hollow
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between the pole pieces thereby allowing
for a major reduction in the mass of the
moving system. This LOW MASS permits the
Shibata type stylus to trace the most
intricate modulations of stereo and CD -4
record grooves with a feather -light tracking
force-as low as 3/4 of a gram.
This results in super -linear pick up especially
at the higher frequencies of the audible
spectrum, which other cartridges either
distort or fail to pick up at all.This low
tracking force also assures minimal erosion
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This family of LOW MASS Cartridges is also
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Tunable from 20- to 20,000 Hz,
this solid state component is compatible with 600 ohms loads and up,
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Overall noise and distortion are
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noise is more than 97dB below
rated output with open inputs.
Providing either crossover or
bandpass functions, the VFX-2 utilizes two continuously variable filters per channel, and filter roll -off
is at a fixed 18 dB/octave.
Applications include stereo biamping, mono tri-amping, and combining the bandpass filter with the
normal two-way crossover on a
mono signal. And all connections
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and includes a clear plastic cover
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Check No. 13 on Reader Service Card
new models as far as could see, but
there were updatings and some new
accessories. At Ampex, they were
showing a new model of Frank Rush,
the dean of field reps. Devoid of some
20 odd pounds and shorn of his Confederate cavalry officer's moustache,
hardly recognized the man. Frank
showed me what is called a "Search to
Cue" device for the Ampex MM -1100.
For use as an aid in mixdown and
overdubbing, the unit can place a
zero reset or cue point anywhere on a
tape, in either the Stop, Fast Forward,
or Rewind position. An hours, minutes, and seconds counter with an
LED digital readout gives the position
of the tape. Punch in the Cue button
and the machine will search forward
or backward until it reaches the preset
cue position. Press the Play button simultaneously with the Cue button
and it will find the cue spot, stop the
transport, and go immediately into
Play mode. The system is accurate to
within plus or minus one half second.
I wish they would make such a gizmo
for the Ampex 440, if only for the super -accurate counter function. Ah,
I
well!
Eventide Clock Works and Lexicon
were showing the latest models of
their digital delay systems. There have
been various updates, not the least of
which is an expansion of dynamic
range beyond 90 dB. Cost has come
down, but there is a way to go before
these units are affordable for far-out
experimenters in quadraphonic synthesis.
In the dbx room, they were demon-
strating the latest direct -to-disc
Sheffield record, #4, which had been
encoded with the dbx system. With
the master lacquer having a S/N ratio
of over 80 dB, this might seem like
overkill, but you'll have to judge for
yourself. All I can say is that the record
was totally noiseless and sounded sensational.
Now to the business of quadraphonic sound. Columbia was on
hand in the Patio Room with the most
advanced of their SQ decoders. They
had gone to the trouble of bringing in
sound -absorbing panels from a studio, and with the room acoustics fairly
well tamed through this expedient,
the sound of the Ben Bauer -designed
Leslie DVX speakers was excellent. In
a variety of pop and classical items, we
heard fine quadraphonic imaging and
sound localization, and this was unquestionably the best SQ demonstration heard at any of the hi-fi shows.
Sansui held sway on the fourth floor
and, with four JBL monitor speakers,
gave a good representation of the ca-
pabilities of QS. Most impressive was
the performance of their latest quadraphonic synthesizer, which can do
wondrous things with stereo records.
Nippon Columbia was demonstrating
their latest UD4 hardware with a variety of recordings using this system.
The sound was clean and firmly localized and received some quite favorable comments.
Now to CD -4. JVC was showing
their new Mark Three CD-4 system
built around a phase -locked -loop
modulator, which is said to give significant improvements in sum and difference frequency response, S/N ratio, dynamic range, and distortion. In
a joint effort between JVC and RCA, a
similar type of PLL CD -4 modulation
system was introduced by RCA which
they call the "Quadulator." John
Eargle, President of the AES, presented a paper on the new JVC system, in
their behalf, as did Greg Bogantz of
RCA for their new Quadulator. There
is no doubt that these new systems for
CD -4 have made an audibly superior
product. I have several experimental
discs at home, and there is no question of the increase in quality over the
same recordings made with previous
systems. There is a great deal more to
this development. had the privilege
of visiting the JVC Cutting Center in
Los Angeles as the guest of John
Eargle and will be giving you full details of my visit and what I learned
about the new modulation system in
an upcoming issue.
Finally, before leave the subject of
the 51st AES convention, would be
most remiss if I did not mention the
absolutely sensational entertainment
presented to us at the conclusion of
the awards banquet. Two virtuoso
performers on the ARP electronic
music synthesizers, Tom Piggott and
Mike Brigida, along with a very accomplished rock drummer, gave us a
quad concert which was stunning.
The sound system was a giant Altec
theater system in each corner driven
by their new 400 -watt amplifiers, augmented by no less than Gene Czerwinski's Cerwin Vega corner plugs as
used in the movie Earthquake, driven
by a mere 6000 watts. Crossover was at
30 Hertz through the new Crown VFX
crossovers! The boys gave us a number of great tunes but the absolute
end was MacArthur Park, which was
the most sonically dynamic and exciting sound
have ever heard...at
least as a sheer sound experience. The
sight of the AES engineers and their
wives roaring their approval and
stomping and whistling for encores
was something won't soon forget.
I
1
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I
AUDIO
18
www.americanradiohistory.com
AUGUST, 1975
Twelve brand new pages. Fortyseven JBL components-dividing
networks, lenses, horns,
transducers, everything.
Lots of these goodies have never
been available as individual
components before. (They've been
performing inside JBL's newest
professional studio monitors.)
Write us. 'He'll send you the
catalogue, free, along with the
name and location of your nearest
authorized JBL Loudspeaker
Components Dealer.
He's Important. Besides all those
components he's got a fresh
supply of the new JBL Enclosure
Construction Kits that tell you
everything you need to know about
building your own JBL enclosure.
Fill out this coupon and send it
along to JBL, the people who
wrote the book on sound.
3249 Casitas Avenue
Los Angeles 90039
UBL
Gentlemen:
can't beat the price. Send
me the book.
I
Name
Address
City
Check No. 19 on Reader Service Card
State
Zip
James B. Lansing Sound, Inc.
High fidelity loudspeakers
from $99 to $3210.
A.
Dear
Transient IM
Dear Editor:
Thank you for publishing the Leach
article on "Transient IM Distortion in
Power Amplifiers" (Audio, Feb., 1975).
This is the type of analysis that is very
much needed in the design of audio
equipment, to take it out of the "arts
and crafts" category and give it a firm
scientific basis.
From 1948 until about 1968 (when
bought my first transistor emplifier,
I
1968.
The best praise I have for Leach's
is to say that I wish I had written
article
it!
Curtiss R. Schafer
Sandy Hook, Ct.
More on TIM
Dear Sir:
In his otherwise excellent article on
transient IM distortion (TIM) in the
February Audio, Prof. Leach states
that operational amplifiers like the
741 are prone to TIM because of their
low 2 to 5 Hertz open loop bandwidth. In audio design, as in servo and
other control systems, the term
"open -loop" gain means gain around
the entire forward and feedback
paths. But in op amp terminology,
"open -loop" response means the response of the device without external
feedback. The compensation controlling the bandwidth is usually lead
type, rather than lag which (as he
notes) reduces TIM instead of increas-
ing it.
The slew rate of the 741 is about 0.5
volt per microsecond-roughly 5000
times faster than it would be if lag
compensation were used. This fast
slew rate insures that any "holes" resulting from transients will be so brief
have critically
as to be inaudible.
22
compared 741s with high grade tube
circuits and could hear no difference
(closed -loop gain was limited to 20 dB
max.). There may be ways of using op
amps that could lead to problems, but
local feedback around each op amp
will prevent this.
Donald E. Phillips
Cedar Rapids, Iowa
I
a
Dynaco Stereo 120), my standard of
comparison was a vacuum tube amplifier that
designed and built and
wrote up for Audio (Engineering) in
1948. All stages were push-pull. The
output, from a pair of Wetern Electric
300 -Bs, was 30 watts, at about 2% IM
distortion, and the power curve was
within 1 dB from 20 Hz to 22 kHz.
There was no feedback of any kind.
My friends used to bring in other
amplifiers for A -B tests, especially
some of the early transistor jobs, and
this old 300-B amplifier always won
without any argument, until about
I
Editor:
The Author Replies
The 741 op amp is internally lag
compensated by a 30 pF capacitor.
This is necessary to prevent oscillation
when external feedback is added.
Normally, when the op amp is used
with external negative feedback, the
bandwidth of the closed -loop amplifier is reduced by placing a capacitor
in parallel with the feedback resistor
from the output terminal to the inverting input terminal. This capacitor
increases the feedback at higher frequencies, thus reducing the bandwidth of the closed -loop amplifier. If
the feedback loop is broken, the capacitor has in effect increased the
bandwidth around the complete forward and feedback paths, and this is,
technically, lead compensation. However, in the case of the 741, lead compensation in the feedback loop is not
necessary for stability since the op
amp is already internally lag compensated for this purpose.
Although lead compensation in the
feedback loop of an op amp will reduce its tendency to produce TIM
when used as a voltage amplifier on its
own, we must examine what would
occur when this op amp is included in
the forward path of a power amplifier
with negative feedback of its own.
Since the bandwidth of the op amp
has been reduced by "local" lead
compensation in its feedback loop,
the open -loop bandwidth of the power amplifier as a whole has been reduced. This can lead to TIM in other
stages of the amplifier, although this
depends heavily on the particular de-
compensation (these exist, but are not
in production), and more importantly,
the local negative feedback in each
internal stage. This way the op amp
will be capable of being tailored to
meet the specific objectives of the
amplifier designer. Otherwise, think
most IC op amps are better suited for
d.c. and low -frequency instrumentation amplifiers. However, some of the
IC amplifiers designed for r.f. applications may be ideally suited for audio
purposes. have not investigated this
in any detail.
Whether IC op amps are suited for
mixer and low-level applications
where they will not be inside the
feedback loop of another amplifier is
something have not investigated.
would refer those interested in this
application to Hoge, W.J.J., "Tubes
Versus Transistors: A Further Comment," J.A.E.S., June 1974, p. 338. Mr.
Hoge gives the results of an actual listening test performed on commercially available mixer amplifiers. His
conclusion was that mixer amplifiers
which have open -loop bandwidths
smaller than the audible frequency
spectrum sound inferior.
In my article on TIM, concentrated
on describing its worse possible manifestation in power amplifiers. There
did
are more subtle effects which
not describe relating to how the THD
of an amplifier varies with frequency
at a constant power level. If the amplifier's THD increases rapidly with increasing frequency, a subtle form of
TIM can be triggered by wideband
audio signals with excessive high frequency levels, even though the input
stages do not clip. believe this form
of TIM is the one most likely to be
produced by a commercially available
amplifier.
I
I
I
I
I
I
I
W. Marshall Leach
School of Elec. Eng.
Geo. Ins. of Tech.
sign.
Nearly all state-of-the-art power
amplifiers today employ an op amp
input stage, whether discrete components or an IC. prefer the discrete
designs until some IC maker markets a
unit in which the amplifier designer
can adjust the internal frequency
I
FTC Violators
Dear Sir:
Although the FTC has passed the
"honest power in advertising" rule, it
has had no effect whatever in our
area. Ads still flood the newspapers
here claiming 200 -watts for 8 -track
AUDIO AUGUST,
1975
You never had it
good.
You may be asking yourself
how we could possibly
know what you've ever had
-and how good it was.
Well, we couldn't. Except
when it comes to Akai's
(Akai's new GXC-39D stereo cassette deck.)
new GXC-39D.
Then we say with what it has and for what it costs you never had it so good.
This cassette deck is so good you can push a button at a certain spot in the tape and
it'll remember. And go back to it anytime you want.
Flick on the Dolby* switch and it'll filter out any bad sounds going to your speakers.
Flick another switch and it's set for low noise tape.
Push another button and it'll pause in the middle of a recording. Push it again and
it'll start again, smoothly.
Just turn on the GXC-39D and your tape will be running across Akai's own glass
and crystal heads. We developed them.
If you're going to get big, you gotta be good.
Lights pop on to remind you the tape
We're good.
is running.
More lights pop on if the recording level
is too high.
It has direct function controls so you
can go from play to forward to rewind and
back to play non-stop.
And it comes in Akai's professionally
styled brushed aluminum finish.
The Akai GXC39D stereo cassette deck.
We never had it so good, either.
-
-
-
Akai America Ltd., 2139 E. Del Amo Blvd Compton. Calif. 90220
"Trademark of Dolby Laboratories. Inc
.
www.americanradiohistory.com
THE
tape players. phoned several of these
advertisers and none of them was
aware of the rule; most of them refused to believe me. And one man
said, "Even if there is such a ruling,
they'll never bother with us-we're
I
SOUND VAULT
too small."
I'm sure this problem exists all over
the country in smaller cities. To what
department of the FTC should one
send clippings of offending ads, along
with a letter asking the FTC to inform
the violators that they are wrong?
Bruce Cullom
Sound Town, Inc.
Texarkana, Tx.
The rule most certainly applies to 8 track players as well as receivers and
amplifiers. Inquiries about the rule
should be sent to:
Carthon E: Aldhizer
Div. of Special Statutes
Federal Trade Commission
Washington, D.C. 20580
Tel: (202) 963-7124
In addition, the EIA has published a
batch of data on the ruling, and
should be glad to send materials to
stores in your area. Address Jack Way man, Electronic Industries Assn., 2001
Eye St. N. W., Washington, D. C. 20006.
Telephone (202) 296-5550.
Electo -O -Phonie Enthusiast
Dear Sir:
Since I am an owner of the Elekt-O-
Phonie
Every UD cassette gives you
stainless steel guidepins to keep your
recordings secure.
Tough steel pins form part of the
internal security system inside every UD
cassette.
They make sure your UD tape
runs smooth and winds even. (Ordinary
cassettes have plastic posts that can
wear out and cause wow and flutter.)
These steel pins are another reason
your Ultra Dynamic cassette captures
the very best sounds (both high and low)
your equipment can produce.
Use Maxell Ultra Dynamic cassettes
and you'll always play it safe.
Maxell Corporation of America,
Moonachie, New Jersey 07074. Also available in Canada.
maxell.
For professional recordings
at home.
FU -100's
immediate pre-
decessor, the F/Mc2, I read Professor
Lirpa's review in Audio (April, page
54) with great interest. Almost before I
finished reading I ran to the nearest
Five and Ten Cent store where I
bought an FU -100 for my car. It works
fine on 12 volts d.c. My only problem
came when I fitted the Klipschorns (I
refuse to listen to any other speakers)
into my Volkswagen. It was worth the
trouble, though. Can you imagine my
satisfaction as I cruise down the Boston Post Road on my way to work
every morning at 140 mph, listening to
all eight channels simultaneously?
Alan M. August
N. Providence, RA.
Dear Sir:
My hat
off to Professor I. Lirpa for
profile of
the Elekt-O-Phonie Model FU -100
Octaphonic Receiver. One question
plagues me about this obviously
is
his enlightening equipment
sophisticated piece of gear. What
does the "FU" stand for? Frequencies
Unthinkable, maybe?
Jack Stevens
WXCL Radio
Peoria, Ill.
Check No.
21 on
Reader Service Card
www.americanradiohistory.com
24
AUDIO AUGUST,
1975
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CHECK BOX A or B beside each coupon number
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SIGNAL-TO-NOISE- Hi -level: 100 db below full output
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SIGNAL-TO-NOISE
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SIGNAL-TO-NOISE
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DISCRETE -OCTAVE EQUALIZATION CONTROL of ten
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AUTOMATIC CONTINUOUS MONFULL -SPECTRUM LEVEL CONTROL for each channel
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Editor's
of the world's foremost loudspeaker
authorities, including A.N. Thiele, Richard Small, J.
Robert Ashley, J.E. Benson, Murray, and very probably Paul Klipsch, will be leading a series of tutortial seminars
to be held in conjunction with the Australian Institution of
Radio and Electronics (IRE) Electro -Acoustic Conference in
Sydney, Australia late in August. A special tour has been arranged, the cost of which covers all transportation (including that in Australia), hotel bills, landing fees, tips, but
no meals. Estimated price of the two-week tour is $1400.00
per person from Los Angeles, and this represents a considerable savings for a remarkable opportunity.
The group leaves Aug. 16 from Los Angeles, and there will
be a two-day stopover in Fiji for jet-lag recovery. The tutorial lectures will be held on the 20th, 21st, and 22nd at the
Univ. of Sydney, with the 25th through the 29th spent at the
IRE Conference. There will also be some outside touring arranged, and preliminary plans include a concert at the Sydney Opera House.
If you would like to go on this tour, you must act quickly,
since a deposit of $250.00 must be in by July 20th and the
balance by August 1st. Deposits should go to Bud Edmonds,
Research Associates, 66 Minnehaha St., Manitou Springs,
Colorado 80829 (303) 685-5776. Further information can be
obtained from Edmonds. A remarkable opportunity!!!
HALF A DOZEN
Review
Back in June, the credit for the cover was inadvertently
dropped, and we apologise to Philadelphia Wireless Institute from whose collection the Radiola Model 27 in the
photo came.
Philadelphia Wireless, not incidentally, is one of the nation's oldest and best schools for technical training in the
disciplines related to electricity, radio, and broadcasting.
The faculty believes in classroom education as it appears to
offer better opportunity for back -and -forth interchange between teacher and student. The school also features a variety of radios, TVs, test instruments, and breadboard circuit
set-ups for hands-on training. They are located at 1533 Pine
St., Philadelphia, Penna. 19102.
Stereo
AM
RCA Broadcast Systems demonstrated a proposed stereo
AM system at the recent National Association of Broadcasters meeting in Las Vegas. The proposed system multiplexes the two discrete left and right signals on the broadcast carrier for later decoding by the stereo AM receiver.
Mono receivers would be able to receive a single composite
signal with no degradation in performance.
Hermon
Covers
The Edison Triumph shown on this month's cover represents an unusual transitional unit between the Model A and
the Model B. Its serial number is 256Q9, and it was built
about 1898. It plays either brown or black cylinders, but only
the two -minute variety, and is capable of playing up to 14
cylinders with a single winding of its triple -spring motor.
The unit apparently was a top -of -the -line model and sold
for about $50.00 with the black and brass horn shown. There
was a black, floor -standing horn sold as an accessory.
The Model C reproducer, which goes with this unit, has a
spherical sapphire stylus for vertical -cut cylinders and a
stretched -copper diaphragm. The unit also has a record shaver and a recorder.
The mechanical refinement of the unit is fairly advanced
for the time. The drive belt can be accurately tensioned by
means of a screw which lowers the entire motor against the
belt, and the nickel -plated chassis features replaceable
bearings. A screw -set governor regulates speed.
The unit is owned by an ardent, young collector, Evan
Blum, whose specialty is doing restorations of reasonably
complete machines. Blum also has about a dozen machines
for sale, including a Fireside B which was made for only
about two months. The Fireside B played the four -minute
wax cylinders but was dropped soon after its introduction
because the much superior Amerol cylinders came on the
market.
Blum is currently working on an article about sources of
supply and services for this field, which we hope to publish
in the not-too -distant future. We will be happy to forward
any correspondence to Blum, either about his collection or
about the article.
H. Scott
Hermon Hosmer Scott, one of the handful of inventive
pioneers who helped launch the high fidelity industry when
he founded H.H. Scott, Inc. in the mid -Forties, died in April
after a protracted illness. He was 66 years old.
Scott graduated from the Massachusetts Institute of Technology, receiving his Master's degree in Electrical Engineering from MIT in 1931. He was subsequently employed by the
General Radio Co. as a development engineer, and while
there developed the first sound level meter. In 1939 he designed and patented the R/C oscillator, on which most signal generators have been based for many years.
Another significant development was his dynamic noise
suppressor, a device which materially lowered the level of
scratch on records while preserving most of the musical
content. Originally for radio stations, simplified versions
were later sold for high fidelity. He held more than 100 pat tents.
During 1947 in Maynard, Mass. Scott founded the company which bears his name. The firm became one of the two
best-known makers of high fidelity components (along with
Fisher Radio), and was sold in 1972 to Eastern Air Devices, at
which time he retired.
Scott's lifelong interest in music led to his becoming a
Trustee of the Boston Opera. He was a Fellow of the Institute of Electrical and Electronic Engineers. He received
the John Potts Award of the Audio Engineering Society in
1951, becoming a Fellow of the AES in 1952. In 1961 he was
elected Executive Vice -President of the AES, becoming President in 1962, and joining its Board of Governors in 1963. In
1974 he was elected Executive Vice -President of the AES, becoming President in 1962, and joining its Board of Governors
in 1963. In 1974 he was made an AES Life Member.
E.P.
AUDIO AUGUST, 1975
28
www.americanradiohistory.com
The source of serfection
sound ...tracks at
one gram (or less) in stereo
and discrete.
in
Frankly, perfection doesn't come easily.
Pickering's engineers pursued the idea
of a totally new departure in cartridge
design with all the zeal of true crusaders.
They had a reason ... there was a
demand for a pickup to play both stereo
and discrete (as well as SO and QS) with
total and absolute precision at one gram.
That they succeeded is a remarkable
achievement because this cartridge
successfully tracks all types of records
at forces even lighter than one gram.
It is a real first to do it this accurately.
The Pickering XUV/45000 possesses
excellent performance characteristics that
provide outstanding frequency response
and separation beyond 50 kHz. These
improvements make possible the most
faithful reproduction of the 30 kHz FM -
modulated material on discrete records.
It is noteworthy that Pickering's exclusive,
new design development, which
provides superior 4 -channel discrete
performance, also greatly enhances the
reproduction of stereo records.
The XUV/4500Q features Pickering's
patented Quadrahedral® stylus assembly.
The Quadrahedral stylus assembly incorporates those features that produce
7f
'" for 4 -channel as
extended tnoc
well as stereo. This means that it possesses
not only superior performance in low frequency tracking, but also in high frequency
tracing ability. When combined with the
exclusive QuadrahedronTM stylus tip,
a brand new shape, it can truly be called:
"the Source of perfection in Sound", whether
the playback requirement is stereo, SO, QS
or discrete 4 -channel.
The specifications are so exciting
that we hope you will write to
Pickering and Company, Inc., Dept. A
101 Sunnyside Blvd., Plainview,
New York 11803 for further information.
PICKERING
"for those who can [hear, the difference -
Check No. 27 on Reader Service Card
www.americanradiohistory.com
A.N. Thiele -
Sage of Vented Speakers
Ray
J.
Newman*
RECENTLY A SIGNIFICANT and elegantly -written ar-
ticle describing the nature of vented speaker boxes
was republished in this country (1,2) 10 years after its
original publication in Australia (3), A.N. Thiele's "Loudspeakers In Vented Boxes." I strongly believe this article is
an important milestone in the literature on high -quality
sound reproduction, and that it deserves to be shared with a
wide spectrum of readers. It has already stirred active interest as shown by several notes and letters in the AES Journal
(4,5,6,7) and in recent AES convention papers (8,9).
In his article Thiele investigates the behavior of vented box speaker systems by analyzing their equivalent circuits as
high-pass filters. Using techniques of electrical network
analysis, he arrives at a remarkable tabulation involving not
one, but 28 ordered ways of creating a vented -box speaker
system! The discussion ranges to such matters as the specifics of designing the speaker box, measurement of required
loudspeaker characteristics for proper design, and some especially significant discussion regarding loudspeaker efficiency and cone excursion as they relate to different system
types. The details of some of these matters together with
their implications will be pursued in this article. It should be
understood from the,outset that only the mid -to low -frequency part of the system, roughly below the frequency at
which the cone's circumference equals one wavelength is
being dealt with. This in no way detracts from the importance of Thiele's article, as this region is a most demanding one indeed and generally dictates the size and
performance format of the complete system.
The following important implications of the generalized
vented -box information presented by Thiele are listed here
as an
early broad summary:
Considering the four interrelated matters of low-frequency limit (the 3 dB -down point), usable cone diameter,
maximum cone excursion above the low frequency limit,
and acoustic power output, the nature of many types of
vented systems as compared to sealed systems can be summarized as shown in Table I.
2. A simple but elegant relationship between system efficiency, low frequency limit, box volume, and one parameter
pertaining to the speaker mechanism alone is also described
by Thiele. This relationship is valid for both vented and
closed systems, and although Thiele's table of 28 alignments
indicates that many comparisons are possible (depending
on the type of vented system), one of the more useful alignment types (Thiele's fourth -order Butterworth alignment)
yields the comparisons shown in Table II between a vented and a closed -box system possessing flat response. Again this
implication, stated in three different ways, is a powerful and
useful concept.
3. Thiele's tabulation (Table IV) of 28 ways of creating a
vented system is the most interesting and useful information
of all. Presented in concise format are a large palate of possibilities for creating correctly -tailored speaker -box systems.
Each of these possibilities or, as Thiele refers to them, alignments has its own set of interesting characteristics. As examples:
(a) Some alignments describe how to make systems with
the low -frequency limit higher than box tuning and the
speaker's free -air resonance frequency.
(b) Other alignments describe systems with the low -frequency limit lower than box tuning and the speaker's
free -air resonance frequency.
(c) Still other alignments are realized by using auxiliary
electrical filters or equalizers. These illustrate ways of
trading off box volume for system efficiency in the lower part of the system's operating range.
The possibilities of the alignment table are fascinating
from the standpoint of system design, because they permit a
logical and systematized approach in creating a vented
speaker system. Further, they permit the system to take
many different forms in terms of performance characteristics, box size, and speaker parameters to suit particular design goals. The Alignment Table (Table IV) changes vented box design from something akin to splashing around in the
Dismal Swamp, to having at least a canoe and a compass.
The Alignment Table
The high point of Thiele's presentation is the table of
alignments-methods of properly coordinating the box and
speaker for a specific type of system response (12). Table IV,
presented here, is somewhat simplified from Thiele's table.
The Alignment Details column includes the name of the fil -
1.
*Senior Systems Engineer, Electro -Voice, Inc. Buchanan, Michigan
Table I-Relationships of Parameters of Sealed and Vented
Systems.
Cone Dia.
Max. Cone
Excursion *
Power Output
Same
Same
Same
8
Same
Same
About 1/3
of sealed
Same
Same
X1/3 or
Same
Same
Same
Same
LF
Limit
times sealed
about .6
of sealed
1
or
about .6
of sealed
Same
* Considering only the range above low frequency limit,
maximum excursion occurs at this limit for a sealed system
and at 1.45 times this limit for Butterworth -type (see text
explanation) vented systems.
AUDIO AUGUST,
30
www.americanradiohistory.com
1975
ter that describes the response of the system. QB3stands for
quasi -Butterworth third -order filters, B for Butterworth filters, and C for Chebyshev filters. The Butterworth filters are
characterized by flat -frequency response, and the Chebyshev filters are characterized by small ripples in the response. Note, however, that none of the Chebyshev responses in the Table have ripples exceeding 1.8 dB. Figure 1 illustrates the nature of these two types of response.
The subscripts may be thought of as describing the rate of
response falloff below fa, with the fourth order (subscript 4)
falling off at 24 dB/octave with decreasing frequency, the
fifth order at 30 dB/octave, and the sixth order at 36
dB/octave. Note that all the alignments have basic 24
dB/octave falloff rates due to the mechano-acoustic nature
of the beast, and that the more rapid falloffs are a by-product of the electrical filters or auxiliary circuits required (i.e.,
additional electrical rolloffs of 6 dB/octave and 12
dB/octave for fifth- and sixth -order responses, respectively).
Additional table notations are as follows:
f, = the 3 -dB -down point on the response curve;
fs = the speaker's free -air resonance frequency;
fb = the frequency at which the box is tuned (a function
of box volume, vent area, and length, not of the speaker
mechanism);
Cas = the acoustic compliance of the cone suspension
system (crudely, how "loose" the suspension is);
Cab = the acoustic compliance of the volume of air in
the box (Ccb = NVb, where N is a constant dependent
on the measurement system used, and Vb is box volume), and
Qt = the speaker's "Q" when connected to the driving
amplifier. (This may be thought of as how far down the
speaker's response is at free -air resonance relative to its
i.e. Qt = 0.5
mid -band response in a very large baffle
means that the response is down 6 dB at resonance.)
-
AUDIO
With the above definitions in mind, several observations
may be made. Note that only three pieces of information
(fs, Cas, and Qt) are needed to completely describe the nature of the speaker mechanism alone (assuming amplifiers
with high damping factors) to create a system, and that the
complete system calls for three ratios, involving box charac-
CHEBYSHEV
BUTTERWORTH
7/
1
1
f3 (-3dB)
FREQUENCY
Fig.
ses
1-Nature of Butterworth and Chebyshev filter responcompared.
31
AUGUST, 1975
www.americanradiohistory.com
teristics, low frequency response limit, and speaker characteristics plus the speaker's Qt to be at specified values for a
specific alignment. For a speaker designer, this requires the
selection of a specific alignment (because of some desired
characteristics it possesses), usually coupled with a selection
of low frequency limit (f3), box size, and speaker diameter,
and then careful manipulation of the three speaker characteristics (fs, Cas and Qt) to satisfy the requirements of the
table. In practice, this is a rather complicated matter as the
initial selection of alignment type, f3, box size, and speaker
diameter involve dragging in many external considerations
regarding the amount of power the system must radiate, distortion levels, where the system will be used, etc., which are
beyond the scope of this article.
As the table of alignments appeared not to be generally
known in the U.S. until recently, many, if not most, available
unmounted speakers intended for vented boxes have somewhat random characteristics not necessarily tied to specific
table alignments. For such random characteristic speakers
the moderately large number of table alignments provides
the designer a better chance of finding a reasonable (and
hopefully usable) alignment for his speaker. Let us instead,
however, consider the table from the viewpoint of a
thoughtful designer of speakers who has knowledge of the
table's existence prior to creating his speakers.
The first item to note in classifying the alignments in the
table is that the first nine alignments do not require auxiliary
electrical circuitry or equalization, unlike the remaining 19.
Of these first 9, numbers 1 thru 4 are characterized by having the system's low frequency limit (f3) higher than both the
speaker's free air resonance frequency (fs) and the box tuning frequency (fb). (This appears in the table as entries
showing f:,/fs greater than 1, and f3/fb greater than 1, respectively.) In the case of the first four alignments, the table
a
b
also implies a speaker considerably more compliant than the
air volume in the box (Cas/Cab considerably greater than 1)
and small Qt's if you please (Qt's less than .303), which usually implies large magnets. The remaining unequalized
alignments (5 thru 9) indicate low -frequency limits at or below the unmounted speaker's free spare resonance (f3/fs is 1
or less). Also implied here are box tunings at or above the
low -frequency limit (f3/ fb is 1 or less), stiffer speakers relative to the box air volume stiffness (Cas/Cab of 1.4 to .485),
and more generous Qt's (.383 to .557). In alignments 5
through 9, the greatest novelty is their ability to maintain
output below the speaker's resonance frequency, although
often fairly large boxes are required to do this and rapidly
rising cone excursion in the region of f3 to fb is a by-product. Some interesting possibilities are presented by these 9
unequalized alignments although suspect that, like as not,
most designers of systems would settle on alignment 5 or
one near it.
The remaining alignments (10 thru 28) all require an auxiliary filter. Alignments 10 through 14 can be realized with
passive electrical networks, as the networks here have the
function of removing a natural low -frequency rise from the
response; in other words they "de -hump" the extreme low
end of the system's response. Figure 2 illustrates the nature
of these responses.
Alignments 15 through 19 can best be realized with active
electrical networks. The networks here are required to lift
up the extreme low end, as shown in Fig. 3. These alignments have the interesting tradeoff of box volume for some
efficiency loss (with flat response restored by the equalizer)
at the extreme low end of the system's range. These alignments can permit smallish boxes to have rather low cutoffs
(note the moderately large values of Cas/Cab). This may be
seen by noting the similarities between alignments 4 (an un equalized alignment) and 15 (requiring a lift equalizer).
I
II-
C
Table
Relationships of low -frequency limit, box size,
and efficiency between sealed and vented systems.
f3
FREQUENCY
2-Nature of response of alignments
through 14 before and after addition of the required auxiliary filters.
Fig.
Limit
Box Volume
Efficiency
Same
Same
4.5 dB greater
(or 2.8 times sealed)
Same
About 1/3 of sealed Same
About 0.7
Same
LF
10
Same
octave)
of sealed
(1/2
C
1.0
1(1
1
--
0.8
f3
FREQUENCY
0.6
Fig. 3-Nature of response of alignments 15 through 19 before and after addition of the required auxiliary filters.
0.4
0.2
\\\\\1
--N,
-r
o
0.35
b
i\ '
1
i/
050
SEALED
\
VENTED
,....
0.71
10
FREQUENCY
FREQUENCY
``
141
2
0
2.83
(f/f3)
f3
5-Cone excursion as a function of frequency for Butterworth -aligned vented systems and for sealed systems,
with and without filters (after Thiele).
Fig.
4-Nature of the response of alignments
through
before and after addition of the required auxiliary filters.
Fig.
20
25
AUDIO AUGUST,
32
www.americanradiohistory.com
1975
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Note here that the speaker Qt values are about the same
(around 0.3) and the Cas/Cab values are about the same
(around 3.0). This would permit taking the same speaker in
the same box and altering the vent or box tuning to obtain
f/fs = 1.45 for alignment 4, or to 1.0 for alignment 15 (with
the 6 -dB equalization lift for alignment 15). Thus, by using
the equalized system, it is possible to decrease the low-frequency limit by a factor of 1.0/1.45, at the expense of a moderate amount of efficiency loss in the extreme bassfascinating! The odds against coming up with a correct number 15 alignment by splashing around in the swamp of empirical cut and try without Thiele as a guide are vast.
Yet another group of alignments, which can probably be
best realized thru the aid of active filters, are numbers 20
thru 25. In these cases, the filters are required to restore an
unequalized system -response characteristic that progressively begins to resemble a dip between the low -frequency
limit of the system and its mid -frequency response as alignment number 25 is approached. A rough idea as to what is
being done is illustrated in Fig. 4.
In general, alignments 20 through 25 progressively tend
toward boxes with large air compliance compared to speaker suspension compliance (Cas/Cab is 1 or less), which often
implies large boxes with the reward being a low frequency
limit usually substantially below the speaker's free air resonance, (Alignment 25 has its -3 dB point at about 0.4
fs-with a moderate filter boost of only 6 dB. Note that the
electrical filters employed with these alignments (as well as
those employed with the other equalized alignments discussed) progressively cut off electrical input to the speaker
system below its low -frequency limit (f;), which is an aid in
reducing low -frequency cone excursion in the region
where such excursion gives little fundamental acoustic output (but often appreciable distortion). The conservation of
amplifier power below f:, also tends to make up for the increased amp output required for the boost filters used by
most of the alignments 15 to 25 in the range above f,.
It is difficult to completely sum up this table of alignments
as it contains so many unusual possibilities for vented systems with the most interesting physical realizations of these
possibilities often lurking within the fs's, fb's, and C's of the
tabulation in tantalizing, mind -twisting ways. Some of the
gross characteristics of groups of these alignments have
been discussed here to illustrate a few of the meanings of
the table and pass on the realization of the many possible,
often highly sophisticated, ways of dealing with the
seemingly simple task of putting a hole in a speaker box.
System Efficiency Relations
A highly significant matter which deals with relationships
between several system parameters and efficiency is developed by Thiele. As Small points out in his project note on efficiency (13), several writers have realized the significance of
Table III-Comparison of output, Cone Diameters, and
Cone Excursions of Vented Box and Sealed Box Systems under certain conditions.
f
f3
Excursion (closed)
Excursion (vented)
Increase in output
of vented system
for same excursion
Increase in dia.
of sealed box piston
to match output of
vented box at same
excursion
Large
Large
Large
2.80
2.00
1.33
1.12
7.80
4.00
1.77
1.25
1.67
this (14) (15) (16), but Thiele appears to have been the first to
record it in the literature. Knowledge of the way system
parameters affect efficiency is quite important since amplifier power, even now, is not unlimited, and a designer has to
contend also with the problem of speaker destruction, especially in trying to reach live performance sound pressure
levels. Efficiency describes how much electrical power input
is needed for a particular acoustic power output. This power
output, coupled with the size and characteristics of the listening environment, are what determines pressure levels in
the environment. Currently, when home speaker designers
are reaching for ever -smaller boxes and also trying to maintain an adequate low frequency limit, a knowledge of when
the absurd is being approached or of ways of obtaining the
best return from moderate -size boxes would seem important. Thiele shows how to grasp this situation in a usable
manner for both vented and sealed enclosures. The relatively simple expression that helps to do this is (17) which can be
restated as:
E = 16 x 10'12 f3 VbK,
Where E is the conversion efficiency presuming radiation is confined by a large flat surface (or radiation into a
half space);
f3 is the frequency at which the system's output is 3 dB
down;
Vb is the internal volume of the box (cubic in.). In the case
of sealed systems, this presumes that the stiffness of the air
in the box is much greater than the stiffness of the loudspeaker mechanism, and
K is a factor dependent on specific system type-usually 1
to 2 for sealed -box systems, and 3 to 4 for vented, un equalized systems.
This expression is indicative of the efficiency of a system at
low frequencies (wavelength greater than speaker circumference), but if good total system design is followed, the efficiency over most of the audible range probably should be
less than 3 to 6 dB below this level.
Of interest on first inspection is the powerful effect of f:,,
which is raised to the third power. Thus, cutting f:, in half
means reducing efficiency by 8 times, or 9 dB. Of lesser influence is the effect of Vb, with the implication that every
time box size is halved, so is efficiency (i.e., 3 dB). As noted
in the definition, the K factor is between 1 and 2 for most
sealed -box systems, and between 3 and 4 for most simple
vented systems, although values of 9 to 18 are possible for
some vented systems requiring auxiliary filters.
Small (18) points out that comparison of a common non equalized number 5 alignment with a sealed box can yield
the conclusions presented in tabular form at the beginning
of this article. Having 4.5 dB of additional efficiency available for the same low -frequency limit and box size can be
useful when a designer is working near the limits imposed
by very low efficiencies-chiefly very large amplifier requirements and danger of electrical burnout. As home systems often tend to maintain excellent low -frequency performance with the smallest reasonable box size (of even
greater interest now, with 4 -channel systems), the information in the efficiency equation can be pit to good use by
employing vented systems to decrease fa or decrease box
size, while maintaining the same efficiency as a closed -box
system.
Cone Excursion Considerations
1.00
1.25
1.41
2.00
3.00
1.41
1.15
1.06
Figure 5 is reproduced from Fig. 10 of Thiele's article (19).
Relative cone excursions are illustrated for three cases of
sealed -box and three cases of a vented -box of the Butterworth -type alignments. Note the minimum excursion at f/f,
= 1 inherent in the vented system. Cone excursion in real -
34
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\VSB_E SO, \9,
COVDACT
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The ADS L71O and L81O are four driver, three way
speakers for audiophiles who demand studio
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enough for bookshelf placement. These systems
share exceptionally wide -range frequency and
power response that places them in the
small select group of reference quality
speakers without demanding the usual
penalty of size and price.
We invite you to test them
against any high quality
speakers regardless of cost.
Listen how accurately the virtually massless 1" soft-dome
as a conventional speaker of the same area.
Then train your ears on the woofers. They are
small in diameter for optimum transient and
power response; this extends clarity and detail
dow-n into bass. It is elegantly accomplished
by two active, perfectly phased drivers with
Lnpr.- cedented lateral excursion. You never before heard a bass drum come so much alive.
Fkwless consistency in all these qualities
u -compromising
tweeter follows every
detail of a solo violin.
Notice how uniformly
the unique mid -range
driver reproduces the
subtleties of a familiar
voice -no brassy sound
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Your local ADS dealer will proudly
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izable systems can be a very small value compared to the
higher -frequency excursions at the same output power. It is
fascinating to watch the cone become essentially motionless
at f:, while high sound levels are produced by the system.
Peak excursion for the vented system is reached at 1.45 times
the low -frequency limit, and decreases as f/f, continues to
increase. In contrast to this, closed -box systems reach their
near -maximum excursion values at in -box resonance and
show a constant drop with increasing frequency at a given
output level.
The differences in the plots below f/f, = 1 are due to the
effects of auxiliary filters being applied in four of the six examples. The particular examples portrayed involve specific,
carefully -coordinated, filter -loudspeaker -system combinations chosen for complementary characteristics. The
highest excursion curve of a given box type is associated
with an unfiltered system, the middle curve requiring use of
a first -order filter (6 dB/octave decrease of the electrical input to the system with decreasing frequency below f/f3 = 1)
and the lowest curve requiring a second -order filter (12
dB/octave decrease in system input below f/f3 = 1).
Note that low -frequency -cut filters can be applied to any
kind of system, but in alignments 10 through 27, the low-cut
feature is automatically a part of the required auxiliary filter.
(Alignments 10 to 14 specify first -order filters, while 15
through 27 specify second -order filters.) Thiele believes the
input -extinguishing action of the filters below the low -frequency limit of the system is desirable, and reasonably so,
since the filter action:
Table IV -Summary of Vented -Box Alignments, after Theile.
Alignment
Details
No.
Type
1
Q B3
3
QB3
QB3
4
Q B3
2
5
B4
6
7
C4
C4
C4
C4
8
9
10
B5
11
C5
C5
C5
C5
12
13
14
15
16
17
18
19
Aux. Ckts,
Required
Box Design
B6
C6
C6
C6
C6
f 3/fs
f
2.68
2.28
1.77
1.45
1.34
1.32
1.25
1.18
10.48
7.48
4.46
2.95
.180
.209
.259
.303
no
no
no
no
1.000
.867
.729
.600
1.000
.935
.879
.847
.838
1.414
1.055
.729
.559
.485
.383
.415
.466
.518
.557
no
no
no
no
no
1.000
.852
.724
.704
.685
1.000
.934
.889
.882
.877
1.000
.583
.273
.227
.447
.545
.810
.924
1.102
yes
yes
yes
yes
yes
1.000
.850
.698
.620
.554
1.000
.868
.750
.698
.659
2.73
2.33
1.81
1.51
1.25
.299
.317
.348
yes
yes
yes
yes
yes
1.000
.844
.677
.592
.520
.404
1.000
.954
.917
.902
.890
.876
1.000
.722
.500
.414
.353
.276
.408
.641
3/f b Cas/Cab
20
B6
21
22
23
24
25
C6
C6
C6
C6
C6
26
27
1.000
.778
1.000
C6
.911
28
Q 83
.952
.980
B6
.191
Qt
.371
.399
.484
.513
.616
yes
yes
yes
yes
yes
yes
.732
.110
.518
1.503
yes
yes
1.89
.328
yes
.431
.461
A. Conserves available amplifier power by more nearly restricting its use to the part of the low -frequency spectrum
that the speaker system is capable of reproducing well, and
B. Reduces distortion caused by the speaker being driven
to what would be (without a filter) its largest excursion in a
frequency region where acoustic output is becoming rapidly diminished.
Considering the frequencies above f/f:, = 1, a tabulation is
shown in Table III for the ratio of cone excursion of a
closed -box system to that of a vented -box system, assuming
the same output power is available from each. In one column difference in excursion is tabulated, presuming the
same available piston size for both systems. A second column translates this excursion to the increase in power output required to bring the excursion of the vented system up
to that of the sealed unit. The third column shows the increase in piston diameter of the sealed -box system necessary to match the output of the vented system if the excursion must stay the same. The last column is especially interesting because it illustrates that as the frequency of a Butterworth -aligned vented box approaches three times the
low -frequency limit, the vent ceases to function. At low frequencies, the vented system operates as if it were a sealed
system with an ever-growing piston size, until at f/f3 = 1 the
equivalent piston has grown to immense size. This explanation is appreciably better than the naive concept that, if
both sides of the cone were used through venting, the effective substitute speaker would have twice the area (or 1.41
times the diameter). Actually this equivalent substitute
speaker would be this size one-half octave above the low frequency limit, and it would grow rapidly as the limit is approached.
There is a most interesting connection between the substitute speaker matter and the matter of the efficiency increases available through venting. Together these matters
imply that f, can be pushed lower through venting, or box
size further reduced without running out of excursion
and/or pushing efficiency into a problem area, if one is satisfied to deal with the excursions presented by current
sealed -box systems. Venting also has something to offer if
one is concerned about reducing excursion at a given level
of size and frequency bandwidth in order to further reduce
forms of excursion -related distortion.
Closing Remarks
have tried to deal with some selected topics from a most
elegant and pertinent article in the literature on sound reproduction apparatus. The highlight of Thiele's presentation
is the tabulation of 28 ways of designing a vented -box system and doing it properly every time. Topics dealing with
efficiency and excursion were singled out as having special
importance in discussing what in vented systems is different
and significant from the more normal sealed -box type of direct radiator system. Cone excursion is important, as only so
much is available and many forms of distortion are associated with it, but it is the connection between required
acoustic output levels and the movement of the speaker
cone. Efficiency is also significant as it is the connection between required acoustic output levels and the movement of
the speaker cone. Efficiency is also significant as it is the connection between acoustic output and electrical input requirements and intimately involves the effects of box size,
low frequency system limits, and system type.
The vented system is certainly not new, but it is a tormat
often handled at less than full potential when chosen. To
some extent, this may be a reflection of its relative corn I
36
www.americanradiohistory.com
Today, the skys the limit on what
you can spend. So Philips' down to
earth advice could help you make the
right choice.
Suppose you're
a
true audio
aficionado. Philips presents the most
automated and technologically advanced turntable ever made. The
GA 209.
The electronic 209 is the only
turntable with three DC motors. One
cues the tone arm. The second transports it. The third, a DC servo motor/
tacho generator spins the platter.
The 209 makes listening to great
music easy. Just place a record on
the platter and walk away The 209
takes over. It even measures the record size for accurate cueing and automatically selects the correct speed.
While the record is spinning, the
tacho generator instantly corrects for
power fluctuations, record mass,
styles mass and dust bugs so that
wow, flutter, and drift virtually do not
exist.
The precision ground drive belt
gives you the added advantage of filtering out motor rumble.
Then, after :he record is over. the
209 returns the tone arm and shuts
itself off.
If you
enjoycueing
a
record your-
self and getting performance that surpasses many broadcast tables, the
Philips GA 212 will fit your system. It
has the one fea:'ure that all better turn-
table manufacturers agree on. A DC
servo motor/tacho generator drive
system. Yet, the 212 is the least expensive turntable with this important performancefactor Itvirtuallyguarantees
accurate turntable speed, so audio
problems like wow and flutter are almost non -measurable.
Inside, the 212 is completely solidstate. Theress nothing moving. That
means there's nothing to mace noise
-either mechanical or electronic.
Plus the 212 Yes professicncl 'es7ther
If you're
more interested in a turn-
table that gives a maximum of performance matched with a minimum
of operating involvement, choose the
Philips GA 427.
Move the tone arm over the leadin groove, the platter starts spinning.
Cue down with the hydraulic control,
the 427 takes over. Its low speed 24
pole synchronous motor and precision drive belt means wow, flutter, and
rumble are insignificant.
When the record is over or when
you change your mind (there's a play
interrupt feature) the 427 will return
the tone arm and turn itself off. All
Philips turntables include base and
removable dust covers.
Philips turntables give you
PHILIPS AUDIO VIDEO SYSTEMS CORP.
AUDIO DIVISION
91 McKee Dr ve, Mahwah, N.J. 07430
Check No. 26 on Reader Service Card
Automatic, Electronic,
Philips gives you three ways to
Automated -Electronic.
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a
meaningful difference between models. Visit your better audio shop. Then
consider the Alturnatives.
plexity of design and operation and also a need for more information on what it can do- and how to make it "do" properly. Thiele's article is certainly a most definitive statement
"Simplified Loudspeaker Measurements at
Low Frequencies," J.A.E.S., Vol. 20, No. 1, Jan./Feb.
1972, pp. 28-33.
(7) Small, R.H.;
in these respects.
Thiele's work has provided the theoretical groundwork
at least two commercially -available loudspeaker systems
in recent years: Interface: A and Sentry Ill, both manufactured by Electro -Voice, Inc. Thiele's paper also was the
basis, by way of Small, for a construction project by Messrs.
Lampton, Chase, and De Vries in the December, 1973, and
August, 1974, issues of this magazine.
(8)
for
Keele, D.B.; Jr., "The Vented Loudspeaker: A
Restatement," J.A.E.S., Vol. 21, No. 4, May, 1973, pp.
246-255.
(9)
R. J., "A Loudspeaker System Design Utilizing
Sixth -Order Butterworth Response Characteristic,"
J.A.E.S., Vol. 21, No. 6, July/August, 1973, pp. 450-456.
Newman,
a
(10)
Thiele, A.N.; "Loudspeakers in Vented Boxes: Part II,"
equation #77, p. 472.
J.A.E.S., See
(11) Small, R.H.;
References
(12)
(1)
Thiele, A.N.; "Loudspeakers in Vented Boxes: Part I,"
Journal of the Audio Engineering Society, Vol. 19, No.
5, May, 1971, pp. 382-392.
(2)
Thiele, A.N.; "Loudspeakers in Vented Boxes: Part II,"
J.A.E.S., Vol. 19, No. 6, June 1971, pp. 471-483.
(3)
Thiele, A.N.; "Loudspeakers in Vented Boxes,"
Proceedings of the IRE Australia, Vol. 22, Aug. 1961, pp.
Op. cit.
5,
above.
Thiele, A.N.; "Loudspeakers in Vented Boxes: Part I,"
J.A.E.S., See Table I, p. 388.
(13) Small, R.H.;
Op. cit. 5, above.
E.J.; "Loudspeaker Enclosures," Wireless
World, Vol. 76, No. 1423, Jan. 1971, pp. 2-6.
(14) Jordan,
(15) Kloss, H.; "Loudspeaker Design,",
3, March 1971, pp. 30-32, 56.
Audio, Vol.
55, No.
(16) Finegan,
J.D.; "The Inter-Relationship of Cabinet
Volume, Low Frequency Resonance, and Efficiency for
Acoustic Suspension Systems," presented May 5, 1970,
Ashley, J.R.; Postscript to "Loudspeakers in Vented
38th Convention of the AES, Los Angeles.
Boxes," J.A.E.S., Vol. 19, No. 6, June 1971, p. 516.
Small, R.H.; "Efficiency of Direct -Radiator Loudspeaker (17) Thiele, A.N.; Op. cit. 10, above.
Systems," J.A.E.S., Vol. 19, No. 10, Nov. 1971, pp. 862- (18) Small, R.H.; Op. cit. 5, above.
863.
(19) Thiele, A.N.; "Loudspeakers in Vented Boxes: Part I,"
Ashley, J.R.; "Efficiency Does Not Depend on Cone
J.A.E.S., (See Fig. 10 and equations (81) and (84), pp. 472
Area," J.A.E.S., Vol. 19, No. 10, Nov. 1971, pp. 863-865.
and 473).
487-508.
(4)
(5)
(6)
AUDIO
CROSSWORD
you know your audio terminology! You say you like
crossword puzzles? Herewith Audio presents its first Audio
Crossword. Next time we'll give you a really tough set of
terms to fill in. Answers to this one are on page 79. Good
luck!
So
1.
5.
7.
9.
12.
14.
.4
3
"
:
c:i
..
,:«S:*;.*:':'-
Across
4.
2
1
5
Connecting wires;
cords.
Column in this magazine; Audio
The Authoritative Magazine About High Fidelity.
Two separate signals from two speakers.
Jacks from which signals leave (plural).
A function switch
selector.
Name for 101/2 -in. tape reels.
Down
1. Common name for RCA (audio) plugs and jacks.
2. Individual part of tape, which carries one sound signal.
3. Erase, Record, and Playback parts of tape machine.
4. Tape in an 8-track cartridge is
6. Man who invented a noise reduction system.
8. Volume Units.
9. Units of resistance.
10. Total Harmonic Distortion.
11. Whole
, or semi
; pitch.
13. Initials of editor of 5 across.
r
;S
.
. .
.
:::......
:
8
7
:.:
::
..... :.c.::::::::::::::::-
10::::
:::::'
.:.;.;.;;;
i
':
:4:
.
::::::
12
38
13
14
:;:
AUDIO
www.americanradiohistory.com
AUGUST, 1975
Your experience has taught you
the things that make a FINE microphone.
Now treat yourself to a
test experience with the FINEST.
ASTATIC 800 SERIES
CARDIOID AND OMNIDIRECTIONAL
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Ask your nearest Astatic Distributor or
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In Canada: Canadian Astatic Ltd., Scarborough, Metro Toronto, Ontario
Export Sales: Morhan Exporting Corp., 270 Newton Road, Plainview, New York 11803, U.S.A.
Check No. 3 on Reader Service Card
www.americanradiohistory.com
Philips RM532
Motional Feedback in
Andante 3A
Loudspeakers
George W. Tillett
ABIG PROBLEM loudspeaker designers face today is
the difficulty of producing good bass response from
a small system. As the enclosure size decreases, the
air inside becomes stiffer, which tends to restrict cone motion and force the system resonance higher. For example, an
8-in. speaker with a free -air resonance of 25 Hz might have a
resonance as high as 130 Hz in a one cubic foot closed box.
This generally means that the low frequencies will be distorted, and what bass is produced will be colored. System
resonance is determined by the cone diameter, magnetic
field, moving mass, suspension, and the stiffness of the air
spring Thus, the designer can either trade efficiency for
bass by using some kind of mass loading, he can use a smaller cone, which might increase the intermodulation distortion (and probably cost more due to the increased magnet size), or he can opt for a vent. This vent can take the
form of a tube or duct, but it too must be very carefully designed or it can make matters worse! Alternatively the de-
INPUT
E
EG
AMPLIFIER
GAIN=A
LOAD
/3°
Fig.
1-Block diagram of a system with negative feedback.
found to improve the performance of amplifiers, loudspeaker designers then began to wonder how the same
principle could be applied to reduce the distortion produced by loudspeakers. One might think so, since amplifier
feedback was invented a long time ago, but as Josh Billings
would say, it just ain't so. Although Black and Blumlein were
working on amplifier feedback in 1934 (1), Hanna had filed a
signer could put the loudspeaker inside the amplifier feed- patent for a system of servo (motional feedback) to control
back loop where the distortion could be reduced and the the response of a balanced armature speaker some 10 years
resonances controlled. This concept is called Motional Feed earlier (2), During the next 20 years, many articles on moBack, or MFB.
tional feedback were published, and the problems were
Most engineers believe that when negative feedback was well summarized by Olson (3) in 1940.
AUDIO
40
www.americanradiohistory.com
AUGUST, 1975
In simple terms, negative feedback means that a portion
of the output of an amplifier is fed back in opposite phase,
thus reducing the overall gain as well as canceling some of
the non -linearity (distortion). Figure 1 shows a block diagram of an amplifier with a feedback loop. The gain of the
amplifier is A, thus:
A=
0
EG
If the,feedback is applied and the input voltage increased to
E'-making up for the loss in gain, then it follows that:
Afb
-Ei E°
E°
EG
The gain reduction due to feedback
A
Afb
E°/EG
E°/(EG
-ßE°
=
1
BE°
is
-
therefore:
1-ßA
EG
The quantity 1-ßA is called the feedback factor and is usually expressed in dB. Thus, to say an amplifier has 20 dB of
feedback means that the feedback loop has reduced the
Fig.
used in the Matsushita amplifier. A is the
the pickup coil which provides the feedback
the amplifier output transformer.
3-MFB circuit
driven coil,
signal. T1
is
B is
more or less like a piston below that frequency. heard this
hybrid servo system several times at the Gogny plant in Paris
and was most impressed with the clean bass and overall clarI
ity.
B
Fig. 2-The Gogny twin voice coil loudspeaker. A is the
driven coil and B is the pickup coil. C is made of non-magnetic material and serves only as a mounting piece.
a factor of 10. If the amplifier has been well
designed, then the distortion will have been reduced by a
similar amount.
The question is, how to put the loudspeaker inside the
feedback loop? Well, there are three methods commonly
used. The first uses a separate voice coil to produce the
feedback voltage (or current); the second uses a transducer
to pick up the output signal, and the last takes a feedback
"error" signal from a bridge or other network connected to
the loudspeaker.
gain by 20 dB or
Applications of MFB
40
40 Hz, LOW DAMPING
40
30
20
Figure 2 shows a loudspeaker with twin voice coils developed by Gogny in France, patented in 1954. As might be expected, there are a number of problems associated with this
kind of construction. The pickup assembly must be kept
small to avoid irregularities in the cone radiation, and the
electrical coupling between the coils must be kept at minimum. The Gogny speaker had a very short voice coil, measuring only 8 mm (1/3in.) with a diameter of 11/2 in. The cone
size was 12 in. and the servo control could only function up
to the frequencies at which cone breakup occurred. In this
case, the crossover point was 800 Hz, and the cone acted
AUDIO
About the time Gogny was carrying out his experiments,
or possibly even earlier, Naraji Sakamoto, of the giant Matshushita company in Japan, also evolved a practical double
voice coil loudspeaker. The driven coil was about 11/2 inches
in diameter and the pickup coil was one inch in diameter.
Cone size was 8 -in. and, as in the Gogny system, feedback
was used only up to 800 Hz. Conventional crossovers were
employed with a 3 -in. midrange unit plus a 2-in horn tweeter. The enclosure size was 0.83 cubic ft., and Fig. 3 shows
the basic circuit used in the companion amplifier. T1 is the
amplifier output transformer, and signals from pickup coil B
are taken via two paths to switch SD, with another loop taken from driven coil A. Note the two resistors, R1 and R2, giving a combination of negative and positive feedback, an arrangement often used in amplifiers to obtain zero output
Hz HIGH DAMPING
1-4 l it
80 Hz LOW DAMPING
1
r,---80
Il
I
,
Hz, HIGH DAMPING
i`
'
u. - -
IO
20
1111111
50
100
IK
IOK
FREQUENCY -Hz
Fig. 4-System resonance and damping in the Matsushita
amplifier. Two resonant frequencies, 80 Hz and 40 Hz are
shown, each with high and low damping.
41
AUGUST, 1975
www.americanradiohistory.com
impedance in the days when this was thought desirable. The
feedback loops are taken to the cathode of a pre -driver tube
and control SD will affect the damping, while twin control
SB changes the speaker system resonance as shown in Fig. 4.
Two extremes are shown, 40 and 80 Hz system resonances,
each with high, and with low damping. Although Sakamoto
seems to emphasize the importance of resonance control
and critical damping to get good bass from a small enclosure, the MFB arrangement also reduces distortion, as
can be seen in Fig. 5. Here an 8 -in. speaker with MFB is compared to a similar unit without feedback, in terms of second
and third harmonic distortion.
The same loudspeaker was used with several other amplifier systems, but the MFB circuitry was simpler, although at
least two had bass -lift controls in the feedback loop.
9
I
e
2nd HARMONIC
7
6
5
WITH MFB
WITHOUT
4
3
MFB---
3rd
HARMONIC
2
40
200
FREQUENCY
100
- Hz
Fig. 5-Second and third harmonic distortion of Matsushita
speaker, with and without MFB.
Feedback Via Piezo Material
Now for
a
look at the transducer method
(4)
of MFB-the
most successful being the Philips system developed by Klaasen and de Koning (5) about 7 years ago in Holland. The
present system (reviewed in our April, 1975 issue) consists of
three loudspeakers all housed in a small enclosure measuring only 15 in. H. X 11 in. W. X 8 in. D. The bass speaker has
an 8 -in. cone, and it crosses over to a 5 -in. midrange unit at
500 Hz, with a 1 -in. dome taking over at 4 kHz. These speakers occupy only 550 cubic inches, while the rest of the space
is taken up by a 40 -watt low -frequency amplifier plus a 20 watt unit for the treble and midrange. Truly a case of multurn in parvo! The transducer used for feedback is really an
accelerometer-a disc of piezo-electric material mounted
on the loudspeaker voice coil together with a tiny preamplifier. The voltage generated is proportional to the mechanical movements of the cone, which are compared to
the input signal by the comparator as shown in Fig. 6. The
two signals are 180 degrees out of phase and distortion is reduced considerably, as shown in Fig. 7. This acceleration
feedback effectively increases the apparent mass of the
moving system so the resonance is brought down. The system resonance is lowered by the use of MFB in this case to
35 Hz. This is a dramatic improvement, for without MFB it
would increase to 75 Hz!
The third system of MFB is sometimes called velocity feedback, as it makes use of the back emf generated by the
speaker voice coil due to its motion in the magnetic field. In
other words, the speaker acts as a microphone, and at resonant frequencies, where the cone movement is larger
than the applied signal, an error signal is generated. This has
to be separated from the applied signal and there are several
ways to do this. A bridge circuit is often used (6) and Fig. 8
shows an example. Connected in series with the loudspeaker is network Ze whose phase angle is equal to the impedance of the loudspeaker in the blocked state. The difference
AMPLIFIER
COMPARATOR
Fig.
6-Block diagram of the Philips
RH -532.
le
e
WITH
W
6
16
MFB-
THOUT
MFB
---
14
12
i
Io
4
8-Typical bridge MFB circuit. Ze is equivalent to the
impedance of the speaker in blocked state.
Fig.
6
6
2
4
R1
INPUT
R3
2
40
Fig.
100
300
FREQUENCY
40
100
300
-Hz
7-Distortion of the Philips 8 -in. cone (left) and dis-
1
tortion of the 3A speaker (right), each shown with and with- Fig. 9-MFB circuit developed by NASA.
out MFB.
the sensing network.
42
www.americanradiohistory.com
L1, R1, and R3
form
AUDIO AUGUST,
1975
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-t
-te ESS Heil air -notion transfo -mer Listen to ESS
you'll hear sound as
clear as light.
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inc.
9613 oates drive - sacrament D, =1.95327
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ar-notion trnsformer lorrspeakei syslema..,oird as c ear as ligh for eery requirement
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1
www.americanradiohistory.com
ESS
products are available
AJADA hroug
ESS
CANADA
Announcing
The speaker that
INFINITY'S
www.americanradiohistory.com
wasn't made to sell.
SERVO STATIK lA
Not very long ago, before Infinity Systems was Infinity
Systems, it was a small group of extremely dissatisfied,
conceptually exotic, pighead-stubborn aerospacephysicist/music freaks in a garage.
Our dissatisfaction was with the sound and inherent
distortion in all existing speakers.
Our exotic concepts promised an entire new
technology of audio electronics.
And our obstinate nature made us push those Lorelei
theories into a unique realization: the Servo Statik 1.
We developed the Servo Statik for one reason
to create the world's finest medium of audio reproduction,
regardless of cost. For ourselves, really.
We figured we could then use this new proprietary
technology primarily as a reference standarda benchmark technology, enabling us then to create a
popular -priced line of vastly superior -sounding speakers.
We didn't figure people would actually line up to buy
the appallingly expensive Servo Statik 1.
We were wrong.
The mystique grew. And so did Infinity.
Now we are announcing the
Servo Statik 1A. Without fear
k _
of contradiction we
can state that
no speaker
ever made is as
distortion -free, as accurate,
as capable of as wide a dynamic
range and as great a frequency
response as the Servo Statik 1A.
The system consists of two
electrostatic screens which produce
tones from 70 Hz to 40 kHz, a
separate bass cube producing tones
from 15 to 70 Hz and a servo bass
amplifier/electronic crossover.
Its 15 Hz to 40,000 Hz power
bandwidth means it produces the full
sonorities of the 64 foot diapason
(the largest pipe of a cathedral organ)
as well as the inaudible but vitally
important orchestral overtones.
-
Its 114 dB peak sound pressure levels means it
can fully reproduce the transient peak of every section
in the symphony orchestra, the full volume of a
concert grand piano in the same room, or the raging,
raunchy thrust of the most punching rock sound.
Its midrange and high frequency electrostatic
modules are angled to provide horizontal and vertical
dispersion-creating a life -breathing concert -hall
ambiance that is unrivalled.
Its separate Brazilian rosewood veneer bass cube
houses an 18" woofer with a 35 lb. magnetic circuit and
a motion sensor as the heart of its servo mechanism
system. The servo woofer, driven by its own 150 watt
RMS DC servo amplifier, generates unparalleled
distortion-free bass reproduction; articulate, tight
and accurate.
Its electronic crossovers with high voltage FETS,
and crossing over at 70 Hz and 2,000 Hz, provide
perfect phase linearity over the entire musical spectrum.
In its unprecedented homogeneity and musicality,
the Servo Statik lA is a staggering achievement.
It costs $3,200.
Yet you don't have to spend $3,200 to get typical
Infinity clarity, transparency and depth of sound.
As we said, one of our objectives in conceiving the
Servo Statik lA was to develop a benchmark technology
for a more "realistically" priced line of speakers.
The result? Every Infinity speaker, from the POS II
at around $100 to the Monitor H at about $450, has
achieved superlative reviews from leading testing labs
and audio reviewers.
Very soon Infinity will top these technological
achievements by introducing the DSP Switching
AmplifierTM-not just a new amplifier, but a new concept
of amplification; an esoteric technology that will have
far-reaching effect in the audio and music industries.
We've restricted sales of the Servo Statik lA to a
select family of dealers. Drop us a note and we'll be
happy to tell you the Infinity dealer nearest you.
We hope you'll treat yourself to the experience of
listening to the Servo Statik 1A. Or any Infinity speaker.
You'll discover a totally new phenomenon: live
music without the musicians.
r;
We
get you back to what it's all about. Music.
©1975 Infinity Systems, Inc., 7930 Deering, Canoga Park, Ca. 91403 / TWX 910-949-4919
Check No. 17 on Reader Service Card
www.americanradiohistory.com
voltage is then applied as feedback (7,8). In a more elaborate
version developed by the Ames Research Center of NASA
(Fig. 9), a sensing network is formed by L, R1, and R3; the
speaker voice coil is shown as a lumped inductance with internal resistance.
Velocity MFB systems are also used by LWE, the French
company 3A, and the Belgian firm Servo -Sound. The lastnamed company also uses a non -linear -feedback arrangement to boost the bass at low listening levels. The French
firm calls their system Acoustic Pressure Feedback. It has a
10 -in. bass unit with a 4 -in. midrange and a 2 -in. horn tweeter. The built-in amplifier has an output of 125 watts and is
housed in the speaker enclosure. The system measures a
mere 18 -in. H. X 12 -in. W. X 71, -in. D. A bridge circuit is
used to derive the feedback voltage. At 30 Hz, the bass cone
moves nearly one-half inch with input of only five watts
sine -wave power. The distortion characteristics are given in
Fig. 7. The bass unit crosses over to the 4 -in. unit at 400 Hz,
and the crossovers are built-in. Provision is made for a separate 20 -watt amplifier for the treble and midrange. These 3A
systems are now available in Canada and will be sold here in
the near future.
used with
a CM amplifier the connections inside the amplifier would have to be made by a technician.
Summary
With the growing popularity of quadraphonic sound and
the consequent emphasis on small loudspeaker systems,
MFB would seem to provide some of the answers to the inherent space problems. am sure we will see more high
quality compact systems with built-in amplifiers with MFB in
the not too distant future. If only an MFB system could be
devised that would provide complete room correction
I
too...!
References
Black, "Stabilised Feedback Amplifiers," Electronic
Engineering Handbook, 1934.
1. H.S.
2. C.R.
Hanna (Westinghouse), U.S. Pat. 1,645,282 (filed
11 Oct. 1927.
1924), granted
Olson, Acoustical Engineering, D. Van Nostrand,
Princeton, N.J., 1940.
3. H.F.
4.
H.W. Holdaway, "Design of Velocity
Transducers," Transactions IRE, Sept. 1963.
Feedback
Klaasen and S.H. de Koning, "Motional Feedback
with Loudspeakers," Philips Technical Review, 1968, No.
5. Also E.R. Hanson, "A Motional Feedback Speaker
System," AES Preprint No. 924.
The LWE loudspeaker systems were designed by L.W.
Erath and are now marketed by CM Laboratories, Inc. Unlike the 3A system, the LWE servo -control extends over the
entire audio spectrum, with one element in the sensing net-
5. J.A.
work variable to permit some modification of the bass response. This variable element is called "Room Gain Control," and it has five switched positions. The largest system in
the LWE line uses a 15 -in. bass speaker, a 6 -in. midrange,
and two tweeters, while the smallest, Model 10, is a bookshelf system with a 10 -in. woofer and a 2 -in. tweeter. All
these systems are available separately but if they are not
6.
7.
D.T.N. Williamson, "More Views on Loudspeaker Damping, Wireless World, Dec. 1947.
H.H. Lowell, "Motional Feedback," Electronics, Dec.
1951.
8. E.
de Boer, "Theory of Motional Feedback," Transactions
IRE, Jan. 1961.
Mannenlanar® Tymriani
THEORETICALLY SOUND
MUSICALLY ACCURATE
The MAGNEPLANAR Tympani, based upon
proven concepts, is an important advancement
toward the theoretically perfect speaker.
Low -mass Mylar diaphragm with controlled
tension provides critical damping.
Low diaphragm breakup.
No speaker cabinet to cause resonance,
loading problems, or transient degradation.
Linear power response-no compression of
dynamic range.
8 ohm power amplifier load throughout
the audio range with essentially no inductive
or capacitive reactance.
High power handling.
No high voltage or arcing problems.
Not sensitive to humidity, temperature or dust.
Efficiency: 10W RMS, 500 Hz, 97 dB at
6 feet (Tympani Ill A).
Sound theory... unsurpassed musical accuracy.
Visit your Audio Research dealer today.
STATIC
MAGNETIC
FIELD
PERMANENT
BAR
MAGNETS
SPACERS
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(-.
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a
PERFORATED
STEEL PLATE
if
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1
.
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1[
99.6% PURE ALUMINUM
.006" "VOICE COIL" WIRES
.0005" MYLAR
DIAPHRAGM
Cross-section Tympani IIIA and Tympani IB Tweeter
audio research
corporation
Box 6003B Minneapolis, Minnesota 55406
Tel: (612) 721-2961
®
www.americanradiohistory.com
Magnepan, Inc.
Equipment Profiles
JVC 4VR-5426X
4/2 -channel FM/AM Receiver
MANUFACTURER'S SPECIFICATIONS
FM Tuner Section
IHF Sensitivity: 2.2 µV. 50 dB Quieting: 3.0 µV. S/N Ratio: 68
dB. Selectivity: 60 dB. Capture Ratio: 2.0 dB. AM Suppression: 50 dB. Image Rejection: 55 dB. I.f. and Spurious Rejection: 80 dB. THD: Mono, 0.5%; stereo, 0.8%. Muting &
Stereo Threshold Level: 2.2 µV. Frequency Response: 20 Hz
to 15 kHz ±1 dB.
AM Tuner Section
IHF Sensitivity: 30 NV, internal antenna; 200 µV/m, external.
Fig.
1-Back panel of the 4VR-5426X.
6
J
S/N Ratio: 55 dB. Selectivity: 30 dB. Image Rejection: 45 dB
If. Rejection: 50 dB.
Amplifier Section
Power Output: 13 watts/channel continuous power from 20
Hz to 20 kHz at 4 or 8 ohms, 4-channel operation (15 watts
from 40 Hz to 20 kHz); 30 watts per channel, 8 ohms, 2 -channel operation, from 20 Hz to 20 kHz (32 watts from 40 Hz to
20 kHz). THD: 1.0% at rated output; 0.1% at half rated output. IM: 1.0% at rated output; 0.2% at half power. Damping
Factor: 30 at 8 ohms. Input Sensitivity: Phono, 1.5 mV; AUX
and Tape, 200 mV. S/N Ratio: Phono, 65 dB; AUX and Tape,
75 dB. Tone Control Range: Bass, ±10 dB at 100 Hz; treble,
±10 dB at 10 kHz. Loudness Control: +12 dB @ 50 Hz; +6 dB
10 kHz.
General Specifications
Dimensions: 18-3/4 in. W. x 6-3/8 in. H. x 15-3/8 in. D. Price:
$399.95.
Japan
Victor Company is, as most everyone knows, responsible for the introduction of the CD -4 discrete record in
Japan and, in partnership with RCA in this country, has been
actively promoting that 4 -channel disc format. It is no surprise, therefore, that the company's line of high fidelity receivers (from highest -priced models to this relatively lowcost unit) should include full demodulating facilities for CD 4 record playback. Bowing to demands for universality, the
4VR-5426X also includes matrix decoding for SQ-encoded
records and other matrix -encoded discs such as RM and QS,
though these facilities are by no means as sophisticated as
those found on more expensive units which employ various
forms of logic separation -enhancement circuitry.
The front panel of the receiver is designed along fairly
conventional lines. The upper section includes a blacked out dial panel, which becomes illuminated when power is
applied. Restricted to one tuning meter for reasons of economy, JVC wisely chose to have that meter (at the left of the
dial scale) act as a signal -strength meter in AM, but as a center -of -channel tuning meter in FM. The FM dial scale is linear, and there is a logging scale between the AM and FM
numerals to permit easy referencing of favorite stations. To
the right of the dial scale are the usual stereo indicator light
and the increasingly popular (on 4 -channel equipment) "radar" light, which glows when CD -4 records are played. A
good-sized tuning knob is located at the right of the dial
area.
0
30
10
á
o
10
-20
-30
-40
STEREO THD. 0.27%
MONO
3
THD. 022%
.3
50
60
.1
70
cc
BO
MONO S/N .71 dB
STEREO S/N=65d13
0.1
1.0
10
INPUT -MICROVOLTS ACROSS
Fig.
2-Internal view.
AUDIO AUGUST,
Fig.
3-FM quieting
--
IK
100
300
10K
OHMS
and distortion characteristics.
47
1975
www.americanradiohistory.com
Controls located along the lower, gold -colored section of
the front panel include a lever -style power on/off switch, a
speaker switch (which determines whether the receiver is to
be operated in its "bridged" 2 -channel mode or in 4 -channel, since only one quartet of speakers can be connected to
the unit), bass and treble controls, a mode switch (with positions for 2 -channel, 4 -channel discrete or matrix playback),
a program source selector switch, four small, individual channel level controls, and a master volume control. A pair
of phone jacks, for front and rear plugs of quadraphonic
phones, are located adjacent to the power on/off switch.
There are also a pair of push buttons for tape monitoring
and loudness control activation.
The rear panel of the receiver, pictured in Fig. 1, includes
thumb -screw speaker -connection terminals for the four
speakers, Tape Rec and Play jacks with full 4-channel capability, Phono and AUX input jacks and Antenna terminals for
either 75 -ohm or 300 -ohm external FM antennas and an external AM antenna. A short, pivotable, AM ferrite -bar antenna is also located on the rear panel. There are three adjustment controls needed for setting up your CD -4 cartridge
for optimum separation and lowest distortion, as well as a
pair of a.c. convenience receptacles and an FM detector
output jack for connection of future 4 -channel FM decoders. While a short wire is connected to one of the FM antenna terminals at the factory (it is capacitively coupled to
the line cord to serve as a minimal indoor FM antenna), we
do not recommend its use as a substitute for a true antenna
(indoor or outdoor) if serious FM listening is planned.
the graphs of Fig. 3. Aside from the stereo quieting characteristics (it took 45 µV of signal input to reach the 50 dB quieting point in this mode), the measured performance characteristics of the FM section of this receiver are quite surprising when one examines the relatively simple circuitry
used in this section. JVC has managed to extract really excellent performance with a minimum of circuit complexity
here. Considering the fact that the MPX section is a modern,
phase -lock -loop IC with no tuned circuits to align, we
would have expected a bit better overall separation figures
than we measured in stereo FM, particularly at the high frequency end where separation decreased to 28 dB at 10 kHz,
but this is more of an engineering point than one which
would truly adversely affect audible results, since mid -band
separation is over 40 dB and, more important, distortion
over the entire audio spectrum is quite low (under 0.3% at
10 kHz in mono, 1.0% at the same frequency in stereo) as
shown in Fig. 4.
Amplifier Measurements
JVC elected to give two complete power ratings for the
amplifier section of this receiver, both in strict conformance
with the new FTC audio power rule. The 13 -watt -per -channel figure applies to the full audio spectrum, whereas the
15 -watt -per -channel rating applies if you are willing to settle
for a power band of from 40 Hz to 20 kHz. Equivalent ratings
0
11
111111111111111111.11111111
11111111111111
-20
Despite its relatively low cost, the JVC 4VR-5426X has
some interesting and sophisticated circuitry built into its
compact chassis, a view of which is shown in Fig. 2. The
front-end uses an FET r.f. amplifier and a three -gang tuning
capacitor for FM. The i.f. section includes a bi -polar transistor as well as a multi -purpose IC for amplification, limiting
and detecting. A multi -element, ceramic, tuned filter precedes this IC. A single IC, which incorporates a phase -lock loop circuit, is used for multiplex decoding, and all AM circuitry is contained in another multi -function integrated circuit. The entire tuner section is built onto a single p.c. module, and there are separate modules for the preamp section,
the CD -4 demodulator circuits, voltage amplifier stages,
tone control amplifiers, loudness compensation circuits,
and the main power amplifier sections. The power amps use
a differential amplifier stage and feature direct speaker coupling via protective fuses in each channel. These fuses are
replaceable only after removing the unit from its wood cabinet. While a full schematic diagram is supplied with the
owner's manual, the CD -4 decoder section is shown as a
blank block with no circuit details spelled out.
FM Performance Measurements
IHF sensitivity for our sample measured exactly 2.2 µV, exactly as claimed and, more important, 50 dB of quieting was
obtained with only 2.8 µV of signal applied in mono mode.
Best overall S/N ratio obtained for high-level input signals
was 71 dB, equal to performance obtained with receivers
costing considerably more than this one. Capture ratio measured 2.2 dB, while AM suppression exceeded published
specifications, measuring 53 dB. Stereo sensitivity was 7.0
microvolts, although automatic switching to the stereo
mode took place at signal strengths of just over 2.0 µV -the
same signal level required to overcome muting when that
circuit was actuated. Harmonic distortion at mid -frequencies was considerably better than claimed, with readings of 0.22% in mono and 0.27% in stereo. Quieting and
distortion characteristics in mono and stereo are plotted in
L
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- 50
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THD STEREO
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11111111!111111111111111111II1I3I
10
100
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0.5
THD MONO
111
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10K
FREQUENCY- Hz
Fig. 4 -Separation and distortion versus frequency.
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18.0W ßaî 1.0%
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0.7
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1
ALL CHANNELS DRIVEN
8 OHM LOADS
0.6
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INPUT :1kHz
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0.2
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0.1
10
10
IK
100
-
/ CHANNEL WATTS
Fig. 5 -Harmonic and IM distortion characteristics.
POWER OUTPUT
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1.0
O
0.6
Fo
0.4
I
I
7
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RATED OUTPUT
0.8
=
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4 CHANNELS DRIVEN
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o
1-
0.2
II
1/2 POWER
1
I
100
IK
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WATT
I
10
II
I
1
10K
FREQUENCY- Hz
Fig. 6 -Distortion versus frequency.
AUDIO AUGUST,
www.americanradiohistory.com
1975
www.americanradiohistory.com
Noise
vs signal
111111111111111111111
A-2300 SD. We took someIIIII11111111111
already quite good,
11111111111111/!=!!111 thing
and made
11111111111P"i11111I11I1MI
M111I/:a11111111111111111
Noise is usually defined as
an unwanted disturbance of
some sort. In a tape recorder,
noise does not occur at the
same volume level across the
entire frequency spectrum.
Low frequency hum is
generally louder than high
frequency hiss, but the human
ear does not perceive noise
in that relationship.
The sensitivity of the ear
is not uniform with frequency,
a situation expressed
graphically in the well known
Fletcher -Munson curves.
Since the ear is most sensitive
to sounds in the range from
1 kHz to 4 kHz, low frequencies
(hum) must be substantially
louder than high frequencies
(hiss) for the same apparent
loudness.
it better.
11111.MSM1111111111113111
Ina1111111=1111111
1111111111111I11111111 The
iiiiiiiiiiiii advantages
of integral
iiiiil
IDO
FREQUENCY Re
FIGURE 2
What is weighted
noise?
With an external Dolby
unit, irregularities in a
tape recorder's frequency
response characteristics will
be magnified during the
signal processing, generally
by a factor of two. When the
Dolby circuits are an integral
part of the recorder, however,
the record and playback
electronics can be optimized
for the encode/decode
processing. In addition,
with integral Dolby you
don't have to pay for an
extra power supply,
cabinetry and the like.
Weighting curves simulate
the non -linearity of human
hearing (Fig. 2). When they
are used as filters in signal-tonoise measurements, they make
the resultant specifications
more credible and meaningful.
Comparisons based on
weighted noise figures are
therefore more valid.
D,R
Dolby.
3%DIST
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WEIOPTED SM
RECORDER
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DIST
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.A-
RECORDER
ECOR
3%DIST
100
5
2
3
Rn
5
I
2
3
5
Using the previous
example of recorders A
and B, we now send the
--_
/4"!
overall noise through the
-TIE.
weighting filter and then
FIGURE
measure the remaining
noise. You can see from
You can see from Fig. 1 that
Fig. 3 that recorder A
recorder A has more hiss than
measures 62 dB, while
B, yet the unweighted signalrecorder B measures 65 dB
to-noise ratio would be the
referenced to 3% distortion.
same for both machines
Now this comparison more
(61 dB). Obviously this
accurately corresponds to
method of specifying noise
what the listener actually
characteristics is inadequate
hears and the subjective
and misleading. It gives no
annoyance of the noise.
indication at all as to the kind
of noise measured. Hiss is
add
more annoying than hum
Because you can gain an
because it is more apparent
additional 9-10 dB reduction
at the same relative level.
in noise with the B -type
Dolby system. And that works
out to be 74 dB on the
106
2
FIGURE
Some popular
misconceptions.
RECORD
UPWEIGMTED S/N
%ear
01.e
RECORDER 8
3
5
100
2
3
5
IS
0E
1
Why
Dolby?
www.americanradiohistory.com
DOLBY FM
DOLBY NR
There's no doubt that Dolby is
an effective means of reducing
noise, however the system will
not eliminate any noise present
on the original signal source.
That noise would go through
the encode/decode processing
along with the signal.
Then there's the feeling
that Dolby reduces high end
response in the process of
reducing hiss. Highs are
reduced during decoding,
but in exact proportion to the
extent they were boosted
during encoding back to the
level they were on the
original music. Finally, since
the Dolby system is level
sensitive low level signals
are affected more severely
than high level signals it
should be emphasized that
very high level signals are
virtually unaffected by Dolby.
-
-
-
-
Complete Dolby
flexibility.
The Dolby/FM switch
activates the new 25 microsecond de -emphasis curve for
decoding Dolbyized broadcast
material. In addition, there's
an FM copy switch on the
back of the unit so you can
record the broadcast encoded
while monitoring the program
decoded for a more accurate
listening reference. With the
A-2300 SD you can decode
any external Dolby source.
And the external calibration
controls, including a built-in
tone generator, help you
derive optimum benefits of
the Dolby system through
accurate level settings.
((
Tape it.
There's a unique satisfaction
to be had in personally
selecting and sequencing your
own source material. Enjoy
tapes that exactly satisfy
your particular musical
tastes, your changing moods.
The tapes you make will
bear the imprint of your
individuality. They will
become the expression of
your personal artistic
perceptions. And if you truly
enjoy listening to music, the
qualitative difference that the
A-2300 SD makes can offer
you years of rewarding and
enjoyable musical
experiences.
We've been
making
A lot of the information in
this ad was excerpted from
The White Paper. If you're
interested in tape recording
in general, and TEAC
products in particular, be sure
to get your free copy. You can
do that by writing us. To
audition the A-2300 SD and
hear the audible improvement it makes, just call
(800) 477-4700* to find the
name of your nearest TEAC
retailer. We'll pay for the call.
*In Illinois, call (800) 322-4400
A-2300SD
3 -motor,
3 -head tape
recorders for
over 20 years.
Continually
refining and
perfecting the
fundamentals.
Consistently
providing the
features and
functions that
best fit your
recording
needs. There's
a certain pride
here. A reputation for
quality and reliability
can not be proclaimed. It
must be earned.
T E AC®
The leader. Always has been.
TEAC CORPORATION OF AMERICA
7733 Telegraph Road, Montebello, Calif. 90640
Dolby is a trademark of Dolby Laboratory Inc. ©TEAC 1975
www.americanradiohistory.com
for bridged two -channel operation, as stated by the maker,
are 30 and 32 watts per channel, respectively, all at 8 ohms.
Note, that in the bridged mode, the use of 4 -ohm speakers
is not recommended, nor specified by the manufacturer.
Based on our measurements, all the stated ratings are a bit
on the conservative side. We measured 18.0 watts for 1.0%
THD at mid frequencies in 4 -channel operation, as shown in
Fig. 5. IM distortion, also plotted in this graph, reached its
rated value of 1.0% at an output of 18.4 watts per channel.
Surprisingly, power ratings were limited at the high -frequency end rather than at 20 Hz, where one normally runs
into the higher distortion as one approaches maximum
power output. In the case of the 4VR-5426, distortion remained low (0.1%) for 13 watts per channel output at 20 Hz,
but tended to rise at the high end for the same output, as
shown in the graphs of Fig. 6. Nevertheless, for a 1.0% THD
rating, we would have rated the receiver at a full 15 -watts
per channel, rather than 13 watts. In the case of bridged
2 -channel operation, we measured 35 -watts per channel at
mid -frequencies, but did not plot distortion at other frequencies, since it has been our experience that curves
would have been similar to those obtained in 4-channel operation (but at proportionately higher output power).
Damping factor, measured in the 4 -channel mode, was 32
for 8 ohm loads, while residual amplifier noise (basic amplifier only) measured 87 dB below full output.
+15
.10
i
+5
BASS
0
1.
TREBLE
LOUDNESS
@-30d8
5
-10
-15
10
100
IK
FREQUENCY
10K
-
Hz
7-Tone control range and loudness characteristics.
Preamplifier Measurements
Fig.
Phono input sensitivity exceeded claims, with a bit over
of signal required at 1 kHz to drive the system to
rated output. However, overload capability was rather low,
with only 31 mV of input signal (again, 1 kHz) required to
create distortion in the preamp stage. Users of this receiver
are cautioned not to use high -output phono cartridges with
it, since such use may limit dynamic range. Since most
people who purchase this receiver will undoubtedly be buying a CD -4 cartridge, this problem is not particularly serious,
as these cartridges tend to produce somewhat lower output
than equivalent stereo cartridges.
1.0 mV
Hum and noise in phono (unweighted) was -60 dB as opposed to the -65 dB claimed by the manufacturer, but this
proved to be quite low enough in our subsequent listening
tests. While there are no high -cut or low-cut filters in this
receiver, the tone controls operated much as expected, and
the tone control ranges are graphed in Fig. 7. Also shown in
this graph is the action of the loudness control when set at
-30 dB below full volume. JVC chose to emphasize highs
as well as lows in their loudness circuit, and in our opinion,
too much emphasis was added at the high end. Many experts contend that no treble boost should be introduced by
a loudness circuit or that, at most, it should be just a few dB
at 10 kHz. Hum and noise in the high-level positions of the
selector switch measured 78 dB below full output.
Listening and Use Tests
Comparing CD -4 reproduction with either SQ or
QS disc
playback on this receiver is really a bit unfair, since the CD -4
discs offer noticeably greater 4-channel effects than can be
had with these basic matrix circuits. With the limited separation afforded by the two matrix decode positions, listener
positioning becomes fairly important and you should try to
set up your speakers so that you are located fairly centrally
between them. This receiver definitely favors the CD -4
records, however.
As expected, FM reception was amazingly good, considering price and circuitry. There is, unfortunately, no way to
switch to mono FM when noisy stereo signals are received
and, in view of the fact that automatic switching occurs at
very low signal strength, we had to pass up certain stereo
stations that were just too noisy in stereo though they might
have been acceptable in mono.
In the 4 -channel listening mode (the only one we used in
our listening tests), it's important to use speakers of relatively high efficiency with this receiver, since 13 watts per channel (or 15 watts, if you accept our modified rating) is not really enough power to drive acoustic -suspension or other
fairly low -efficiency speaker types. With the ported, high efficiency systems we used in our listening tests, the 4VR5426X delivered enough clean power to satisfy most listening needs in average -to -small sized listening rooms. When
you consider its overall performance, its 2 -channel "starter"
capability, at more than double the per -channel power and
its measured and audible performance, this receiver is certainly the answer for those who want four -channel sound
but can't yet afford the price of those ultra -sophisticated,
super -matrix with logic plus CD -4, higher -powered units
which can cost more than an entire system (including speakers, turntable and cartridge) incorporating the 4VR-5426X.
If, later on, you want the ultimate of matrix-decoding circuits, you can always add a more elegant, separate, matrix
decoder and still come up with a good working 4 -channel
system at unusually low cost.
Leonard Feldman
Check No. 70 on Reader Service Card
Wollensak 8080 8 -Track Cartridge Recorder
MANUFACTURER'S SPECIFICATIONS
Speed: 33/4 ips. Wow and Flutter: 0.1% wtd. rms. Tape Shutoff: Manual or automatic. Input Sensitivity: AUX, 80 mV;
Mike, 0.25 mV. Output: 1 Vat 0 VU. Distortion: Less than 1%
at 0 VU. Frequency Response: 30 Hz to 15 kHz with Scotch
Classic; 30 Hz to 12 kHz with standard tape. Signal -to -Noise
Ratio: Better than 50 dB without Dolby; better than 60 dB
with Dolby. Dimensions: 19 in. W. x 101/4 in. D. x 5 in. H.
Weight: 17 lbs. Price: $344.95.
Tape recording enthusiasts who associate 8-track machines with automobiles and $99 compacts should take a close
look at the new generation of 8-track units designed for topquality performance. As they did with cassette machines,
AUDIO
52
www.americanradiohistory.com
AUGUST, 1975
The Dual 701.
Some extraordinary test reports about an extraordinary turntable.
Test reports of the Dual 701, in magazines like
this one, have been totally unlike those of any other
component. Not just because the reports are
favorable; none of these magazines wastes anyone's
time reviewing
run-of-the-mill
products; there
are too many good
ones available.
The reports are
different because
of two themes that
The 701's
run through them.
all -electronic, direct One theme
drive, brushless, DC motor has
Hall -effect feedback control and is
acknowledges
energized by a regulated power supply.
that the 701's
performance is actually superior to the measuring
capability of available test instruments. For example,
Hirsch -Houck Labs in Stereo Review found the wow
level of the 701 "essentially at the residual level of
our test record-about 0.03 per cent:' So did
Popular Electronics.
The Feldman Lab Report in FM Guide stated:
"We could detect no flutter whatsoever, and the
low readings that we did get for wow were no doubt
the result of using a record which was not absolutely
concentric:'
Stereo & HiFi Times found "arm friction was
lower than my capability to measure reliably:'
The second theme throughout the reports
is the unequivocal ranking of the 701 at the
pinnacle of perfection in record playback. In the
following quotes, note the absence of such familiar
qualifiers as "one of the" or "among the:'
Stereo Review: "... technical performance
characteristics surpass to a greater or lesser degree
those of any other integrated record player we
have tested:'
FM Guide: "The Dual 701 is probably the
smoothest acting, most rumble -free system we have
ever tested:'
Popular Electronics: "In almost every
respect, the Dual 701 surpassed just about every
other record player-manual or automatic-that
we have tested:'
High Fidelity: ':..the Dual 701 has placed
itself in the select group of products against which
we must measure the performance of others!'
And, the highly conservative English
publication, HiFi News & Record.Review, with
typical British understatement commented: "The
experience of listening to records of the
highest quality on this turntable is not likely to
be forgotten ...you will never again be satisfied
with anything less perfect:'
If you wish to experience the same caliber of
performance as these highly experienced and most
critical of all audio experts, you need only visit your
nearest United Audio dealer and ask for the quietest
turntable ever made. You are in for an
extraordinary experience-with this fully
automatic, single-play, electronic,
direct -drive turntable. $400, including
base and dust cover.
The 701's unique counterbalance houses two
separate anti -resonance filters which absorb
resonant energy in the frequency ranges of the
tonearm/cartridge system and the chassis.
Dual
United Audio Products,
120 So.
Columbus Ave., Mt. Vernon, N.Y. 10553
Exclusive U.S. Distribution Agency for Dual
Check No 38 on Reader Service Card
www.americanradiohistory.com
Wollensak is showing the way with innovations and improvements in these machines. Introduced last year, the
Model 8080 has a frequency response which extends to over
16 kHz and exhibits an excellent signal-to-noise ratio and
low distortion. This new standard of performance can partially be explained by the fact that the machine was designed for use with the new Scotch Classic cartridge tape,
which has better high frequency response than earlier formulations. However, there are real improvements in the
machine itself, as we shall see from the results obtained with
Scotch HO/LN tape.
Styling is neat and workmanlike, with a black and satin
finish on the front panel. The cartridge compartment is on
the left, and under this door are five indicator lights, one for
Record and one for each of the four tracks. The track Select
switch is on the extreme left, along with two other lever
switches for Fast Wind and Eject. Next in line come the two
VU meters, located in recessed panels, slide controls for recording levels, and two miniature microphone sockets.
Then come two groups of three lever switches for the following functions, 2-chan./4-chan. select, Regular/Special
Tape select, Dolby select, Auto Eject On/Off, Repeat Program All/One select, and FM Listen On/Off. Just beneath
the last three is a headphone socket which takes a standard
stereo plug. Input and output sockets, shown in Fig. 1, are at
the rear, together with the Dolby calibration controls, and a
spare a.c. outlet. The FM Listen switch enables the Dolby decoder section to be used independently of the rest of the
unit so that you can decode a Dolby FM broadcast and feed
the signal to the rest of your sound system. Flipping the FM
listen switch turns the unit on without having to insert a
cartridge. The Dolby switch has three positions, FM Decode, Record/Play, and Off. In the first position, the decoder is in circuit for listening to or recording Dolby broadcasts. In the Record/Play position, Dolby encoding is in circuit for recording and decoding for playback. The Off position switches the Dolby section out completely.
The tape select switch has two positions, one for regular
tapes such as Scotch HO/LN, and a Special position for
Scotch Classic tape. This second position changes the equalization of the 8080 so that the characteristics of the Classic
tape are more closely matched. It operates only in Record
mode and doesn't affect playback.
The Auto Eject switch works in conjunction with the Repeat switch. In the record mode with the Auto Eject switch
on and the Repeat at One, the cartridge will record the
selected track and then eject. With the Repeat switch in the
All position, tracks 1 through 4 will be recorded on the cartridge, which will then be ejected. With the exception of the
Pause control which also functions as a Stop switch, the
other controls call for no particular comment.
Measurements
Figure 3 shows the playback response from a standard test
tape, which is now obviously outdated because of the new
standards of performance achieved by Wollensak. This high
level of performance is underlined by the results obtained
---DOLBY
Fig.
1-View of
back panel.
2 OVU
10
100
IK
10K
FREQUENCY
Fig.
Fig.
2-Interior view.
- -- DOLBY
+5
cc
10
5
10
100
IK
FREQUENCY-
3-Playback response from
a
00
I
10K
K
FREQUENCY
10K
Hz
Fig.
Fig.
VU
T1i
o
w
Hz
4-Record-play response with Scotch Classic.
-20
>
-
standard test tape.
- Hz
5-Record-play response with Scotch High Output, Low
Noise tape.
AUDIO
54
www.americanradiohistory.com
AUGUST, 1975
The new Sansui LM
Loudspeakersse
Convention
on its ears.
At the Convention of the Audio Engineering Society
in Los Angeles last May, Sansui demonstrated a new
concept in loudspeaker design.
The reception from these experts-chief engineers
of radio and TV stations, record producers, recording
engineers and sales executives of audio companies-was
even more sensational than we ourselves expected.
And these are the reasons:
Unlike conventional speakers, the LM design incorLM 330
porates a multi -radiational tweeter device. High frequencies
CUT-A -WAY
instead of being lost through encapsulation, are diverted through
three special exponential horns and recovered into sound energy that
adds a breathtaking sense of ambience, and realism. The LM speakers also display
extremely stable and well-defined stereo images. At the same
time, both the transient response and efficiency of the system are
greatly increased. An extra large woofer assembly gives exceptionally
strong bass response ordinarily available only in much larger
and more expensive speakers.
Hear any of the 3 models available
at your nearest Sansui franchised
LM 330
dealer. You never heard music so
)
alive before.
LM 220
Multi -radiational
tweeter
SANSUI ELECTRONICS CORP.
11377 Gardena, California 90247
SANSUI ELECTRIC CO., LTD., Tokyo, Japan SANSUI AUDIO EUROPE S.A.,
Antwerp, Belgium ELECTRONIC DISTRIBUTORS (Canada) Vancouver 9, B.C.
Woodside, New York
Check No. 32 on Reader Service Card
www.americanradiohistory.com
e..__
.,
_.
with Scotch Classic tape, which is shown in Fig. 4. The 3 dB
point for Classic was 16.5 kHz, with response rising from the
3 kHz point. With the machine switched to Regular tape and
using a Scotch High Output/Low Noise cartridge, the results
shown in Fig. 5 were obtained. The -3 dB point here was
14.3 kHz-not all that far under the Classic, though headroom was somewhat less. Response of the Dolby system was
well within the 2 dB tolerance for both cartridges.
Distortion at 1 kHz is shown in Fig. 6 and distortion versus frequency is plotted in Fig. 7. Signal-to-noise ratio, using
a standard A weighting, was 50 dB for the Scotch HO/LN
tape and 52 dB for the Classic, increasing to 60 and 62 dB,
respectively, with the Dolby system switched in. Input sensitivity to read 0 VU was 84 mV for line inputs and 0.24 mV
for microphone inputs. Output at 0 VU was 850 mV. Erasure
was better than 66 dB, and crosstalk (measured at 400 Hz)
was 67 dB between adjacent tracks and 45 dB between
stereo channels. Wow and flutter, that old bugbear of cartridge machines, was measured at 0.18 percent, DIN record play. The maker's specifications give a wow and flutter figure of 0.1 percent weighted, but no details are given as to
the standard so that it is possible that refers to playback only.
Fast forward speed is about 3.5 times the normal record -play
speed of 33/4 ips, and a 90 -minute cartridge was timed at 6.75
minutes. Tape speed was found to be less than 0.25 percent
no getting around the inherent design limitation of the 8 track's inability to rewind for "instant" replay, but how
much of a disadvantage this will actually be will have to be
decided by the individual user. However, the argument for
compatibility in both auto and home tape formats should
not be overlooked, and, of course, one wants the best possible unit for home use.
The 8080 will play quadraphonic cartridges and can make
two -channel recordings as well. There are only two recording amplifiers, so you cannot record in four channels.
For the first use test, hooked up the Model 8080 up to
my sound system and played some Columbia quadraphonic tapes, including Man of La Mancha and Bartok's The
Miraculous Mandarin. Overall sound was clean and spacious with a clarity and crisp definition of transients which I
have never heard before from an 8 -track machine. missed
I
I
3
i
2
CLASSIC
slow.
loo
10
4
FREQUENCY
3
2
//
i
o
H0
+I
o
RECORDING
Fig.
10K
IK
6-Distortion
at
1
7
/*/
/
/
Fig.
CLASSIC
- Hz
7-Distortion versus frequency.
the convenience of four VU meters but balancing the channels was not that difficult. No trouble was experienced in
making excellent stereo recordings from discs or off the air,
although did find it rather tedious to wait while the tape
wound itself before could listen. But then, usually make a
number of short recordings for test purposes, rather than
immediately beginning with the transfer of a complete symphony, for example. As more and more FM stations adopt
the Dolby system (there are over 90 presently), the chances
are that Wollensak's method of Dolby inclusion will save
you money at some time in the future.
Particular attention was paid to the construction of the
8080, particularly to the mechanics involved in head motion
to select the various tracks. Tolerances are very small here,
and any wear or mechanical distortion could cause problems. No evidence of skimping or bad design was found,
and the machine should stand up for years of hard use. Of
course, the heads must be kept clean, as with every tape
machine, and only good quality cartridges should be used.
Wow and flutter figures are greatly influenced by the cartridge itself, and was not really surprised to find one cartridge, the brand of which shall not be named, virtually un playable! The moral is obvious.
George W. Tillett
I
I
+2
LEVEL - VU
+3
+4
kHz.
Listening Test
The first question most readers will ask is how does the
with a similarly priced cassette machine? In
terms of the basic performance parameters, such as frequency response, distortion, and so on, there isn't much to
choose between the two formats at this price level. There's
8080 compare
Yamaha Model B1 Power Amplifier
I
I
Check No. 71 on Reader Service Card
MANUFACTURER'S SPECIFICATIONS
Continuous RMS Power Output: 150 watts per channel, with
8 or 4 ohm loads, both channels driven from 20Hz to 20 kHz,
with 0.1% or less total harmonic distortion. IM Distortion:
0.1% at rated power, SMPTE. One -Watt Frequency Response: 5 to 100 kHz, +0, -1 dB. Power Bandwidth: 5 Hz to
50 kHz, 0.5% distortion. Hum and Noise: 110 dB. Damping
Factor: 100 at 1 kHz, 8 ohms. Input Sensitivity and Impedance: 0.775 V, 50k ohms. Weight: 95 lbs. Price: $1600.00;
UC -1 control unit, $250.00 (optional).
The Yamaha B-1 is one of a new breed of amplifiers from
Japan using vertical field-effect transistor (V-FET) output devices. The unit is beautifully made, solidly constructed, and
AUDIO
56
www.americanradiohistory.com
AUGUST, 1975
A
tribute to appreciation.
Music appreciation. Art appreciation. Appreciation for excellence in
performance. A fulfillment that comes from the experience, rot from :he
parameters by which it was created.
The Contrara Group of loudspeakers is a tribute to that
appreciation. We should not deliberate how Amilio Contrara ias
sculpted the walnut, blended it with cloth and merged it with
technology to bring visual satisfaction. Nor, how he has balanced
the electronics with physics to provide audible gratification.
Ours is only to enjoy. To appreciate. To savor.
Something only our ears and eyes can savor for themselves.
If you enjoy your music and quality craftsmanship, you'I apprec a e
the Contrara Group; it's a tribute to your sensitivity. Write us for additional
information. We'll send you a booklet on appreciation and a ist of
locations where you can enjoy Contrara.
Fair Oaks Ave.. Pasadena, Calif. 91103
64 N.
JENNINGS RESEARCH INC Canadian
Distributors- THE AUDIO GROUP INC.,
CIRCLE 25 ON READER -SERVICE CARD
www.americanradiohistory.com
105 Denison St., Mar<ham,
Ontario
very heavy, weighing about 95 lbs. The UC -1, a companion
control unit with peak -reading power meters and speaker
switches, adds another 14 lbs. After moving this amp about
several times, this writer would recommend a small crane or
fork lift for prospective owners.
The chassis has two heavy side pieces with a sub -floor between for most of the front -back distance. Power transformers and filter capacitors are bolted to this sub-floor,
along with PC and other connectors for all the sub -assemblies including two output -device heat sinks and one power
amp drive board per channel, two regulator boards, a protection board, another large heat sink with 6 regulator transistors and several power resistors, the front panel chosen,
and finally the input amplifier and filter board. The output
device heat sinks are rather large and the output devices
themselves are in a large case-about 50% larger than the
usual diamond -shaped TO -3 output device. The wiring is
neat, and workmanship excellent. The standard front panel
insert takes about 30% of the height, starting at the bottom
of the front edge, and is horizontally grained, clear anodized aluminum, contrasting with the black remainder of
the amp.
Controls with the standard insert are a pushbutton main
power switch and two output level controls. Three light emitting diodes (LEDs) indicate Power On, and either Thermal or Overload Protection circuitry activation.
The UC -1 can either be snapped onto the B -1's front, adding about 2-1/2 in. to the depth, or used in a remote location with its long, heavy interconnecting cable. Controls are
a lever Power switch, lever Rumble -Filter switch, master
speaker On/Off switch, five pushbutton switches for selection of five speaker pairs, and 10 speaker level controls.
These last are driven from the input buffer and amplifier,
and the wipers drive the power amp inputs. This control unit
/ü11llinme00\`1:7i.
Fig.
1-Rear of the Yamaha
B-1
amplifier.
thus allows five pairs of speakers to be compared at equal
volume levels without the insertion of high-level speaker
line pads which could degrade power and damping characteristics. Yamaha must have believed that the B-1 was so
good (with good reason) that it would be used as a reference amp in a demo room set-up for comparisons of high end speakers.
UC -1 Control Unit
The remaining feature of the UC -1 is a pair of wide dynamic range, peak-reading power meters. These meters
cover a dB range from -50 to +5 and a resulting power
range, as calibrated, of 1 mW to 300+ watts into 8 -ohm
loads. These meters are absolutely first-rate. Peak power is
really what counts in regard to amplifier clipping and available headroom. Reading power over such a wide range
without changing meter ranges is very useful and informative, and this system is by far the most accurate and meaningful of any meter set-up seen thus far. The equivalent ballistics are such that the meters accurately capture short duration peaks of long duty cycle, then quickly move up to indicate the captured peak, and finally decay relatively slowly.
The only system which might be superior would be a peak reading power meter which measured actual power delivered into the load by sensing the voltage and current delivered, though no such meter is commercially available
presently.
On the back of the B-1 are 10 speaker output connectors,
two primary power fuses, one unswitched a.c. outlet, a connector for remote turn -on of power, and two pairs of signal
input RCA jacks. One pair of these input jacks is a direct input to the power amp, and the other, labelled Normal, goes
to the input buffer amp. A small slide switch selects either
Normal or Direct input, and a second such switch can activate a 10-Hz rumble filter, with a ground binding post
completing the rear panel. Considering its construction and
features, this amp is outstanding, as it well should be for its
price.
Circuit Description
A good deal of basic information about V-FET technology
was published in the February, 1975 issue of Audio. We will
refer back to some of this description later on.
o+90V
-20V
YT
304
013
II
}
SRI
0.22
OV
()OUTPUT
- 100V
YT 304
Q14
2
o
PUSH PULL DRIVE
o
Q7
R2
(k8
EII
0.22
0
90V
+I2
200
Fig.
2-Interior of the
B-1 amp.
Fig.
V
3-Simplified drive circuit.
AUDIO AUGUST,
58
www.americanradiohistory.com
1975
New from Acoustic Research
The AR -11
A new standard of accuracy from Acoustic Research
Musical accuracy
The AR -11 is the most
accurate speaker system ever
made by Acoustic Research.
Its performance, drivers, and
crossover are identical to those
of the recently introduced
AR -1 On except that the
AR -11 does not incorporate a
Woofer Environmental Control
and the associated crossover
components.
,
The AR -11 is designed for
optimum performance when
placed against a wall, as on a
bookshelf, or slightly away
from two room surfaces, as
illustrated.
New drivers
The AR -11 uses a
substantially improved version
of the 12 inch woofer with
which Acoustic Research
introduced the acoustic
suspension principle to home
listeners, as well as the dome
midrange driver of the AR -3a.
It also uses a newly designed
3/4 inch high range based on the
original high-frequency dome
radiator introduced by Acoustic
Research in 1959. This
highrange incorporates new
diaphragm materials, voice
coil, and construction
techniques that have produced
significant improvements over
earlier versions.
As with all AR speakers, the
workmanship and
performance of the AR -11 are
guaranteed for five years.
These drivers, in combination
with a new crossover network,
have resulted in a speaker
system with uniformly
dispersed flat energy output to
the highest audible
frequencies. The AR -11 is able
to transmit the information from
a program source to listeners
in most positions in a listening
room with an unprecedented
degree of accuracy.
Acoustic Research
10 American Drive
Norwood
Massachusetts 02062
Telephone 617 769 4200
..ELEo.NE COMPANY
Complete specifications of the
AR -11 are available on request
from Acoustic Research.
Please send specifications of the AR -11
Please send a copy of the AR demonstration record The Sound of
Musical Instruments' (check for $5 enclosed)
Name
Address
AU8
Check No.
1
on Reader Service Card
www.americanradiohistory.com
The schematic diagram of the B-1 is rather large and comThere is one more protection circuit, mainly concerned
plicated, with the circuitry for the power amp proper taking with protecting the load, which senses the d.c. potential of
up about 20% of the total space but not including the power both output lines and opens the speaker relay if either outsupply for both channels. Starting with the power supply put line exceeds ±2 V d.c. This circuit also functions as a
section, a small power transformer is connected to the in- time -delay mute during power turn -on, keeping the speakcoming a.c. line without going through the power switch. er relay open for several seconds.
This powers a simple one -transistor, relay -driver circuit.
A complete schematic for the UC -1 wasn't available,
Turning on the power switch grounds one end of the tran- though there is a block diagram, but its operation is fairly
sistor base turn -on resistor and pulls in the relay, which then straightforward. The output of the power amp, suitably atfeeds a.c. to the two main power transformers. It is then easy tenuated, goes first through an a.c. logarithmic amplifier
to turn the amp on from a remote location, a simple contact and then into a linear detector. The d.c. voltage thus proclosure being all that's required.
duced then goes through a d.c. log amp and into a peak The main winding on each transformer feeds plus and hold circuit. The final result is a d.c. voltage proportional to
minus, full -wave rectifiers and two 15,000µF capacitors for the peak value of the log of the power amplifier output voltthe output stages of each channel. The developed voltage is age. This d.c. is used to drive the meter and gives equal deabout ±90 V d.c. The remainder of the windings are used, flection for each decade of power shown on the meter.
one phase per transformer, to develop full -wave rectified
The input buffer amplifier serves to present a high input
d.c. for five voltage regulators which produce +12, ±25, impedance (100K) to the signal source on normal input, pro+40, and -200 V d.c. These are all full electronic regulators vides a low impedance drive for the level controls which are
with error -sensing amplifiers which control series -pass tran- 1 K, and is an active circuit for the 12 -dB -per -octave rumble
sistors.
filter. The overall gain is 1X for input to the level control.
The +12 is used for the output stage protection circuitry, The circuit itself has an N -channel horizontal (or normal)
the speaker switching relays, and the relay mounted on the FET input differential pair in which both output phases are
input buffer amplifier that switches in the capacitors for the differentially combined to drive a following inverting
low-cut rumble filter. The ±25 is used to power the input P -channel H-FET. This stage is operated common source,
buffer amp and the meter electronics of the UC -1. The +40 like a common resistor with a bipolar, with a source deand -200 are used by the main power amps only.
generation resistor of 150 ohms. The second stage drives a
Each ±90 V supply for an output stage is routed through a small power N -channel V-FET source -follower operating
series -pass power transistor, an NPN for the plus and a PNP with a drain current of about 25 mA. Overall negative feedfor the minus, before arriving at the output stages. The back is taken back to the inverting input to set the closed series -pass transistors are normally fully saturated or fully loop gain at about 1.3X for proper operation of the active
on. The drive circuitry for these will be cut off, thus shutting low-cut filter when in operation. This slight gain is taken out
off the supply to the output stages if the load current is ex- by a series resistor that feeds the level controls.
cessive or if the V-FETS get too hot due to restricted ventiThe power amplifier circuitry can best be approached by
lation (thermal overload). Further, if the bias supply for the looking at the output stage, and a simplified schematic of it
power amps (-200 V) or the +40 V fails, the supply to the is shown in Fig. 3. A more complete, though still -simplified
V-FETs is cut off. Recovery from any of the above conditions diagram is shown in Fig. 4. The output stage should be called
is rapid and automatic as soon as the fault condition is cor- single -ended push-pull, rather than quasi -complementary.
rected.
This distinction was discussed on pages 48 and 50 of the February, 1975 Audio. Of interest is the fact that only FETs are
+40V
+ 90V
OI
used from input through output, no bipolar devices are inYT405
corporated, and there are only two output devices.
013
One thing common not only to this circuit but all V-FET
YT304
amps seen thus far is that the saturation voltage drop of
0.2211
Ov
INPUT
,
V-FETs is considerably higher than bipolar devices, and
OUTPUT
therefore the ultimate power for a given supply voltage is
- TJOB
lower than with bipolar designs. A typical bipolar amp deliv-
IR
_V
òl
N
LK15_(21
12)014
!AYT304
,r
Mgt
-I
IHz
90V
200V
NORMAL
4-More complete
17
CC
0.08
O 0.06
Cr
Ó
I
kHz THD, 8 011M LOAD
V, 0.04
J
ó
006
Z34*
1
004g
I-
0.02ÿ
0
2
II
-20
0.08
0
U 0.06
:111111111
1111
.Ir-rr
0
omW
100mW
IOW
1W
POWER
Fig.
5-THD and IM
versus power.
LOAD z
5111
Q 0.04
0.02
î
O
IIIIII
1111I _
0
kW
1111111
111111
IIIIIII
IIIIII11111
IIIIIIIIIIIIII1
111111
THD
VS
FREQUENCY
NO
....iIi......ullIMEM
100
IK
-
,
IIIII%,IIIII
AND
POWE8R'
FREQUENCY
I
LOAD
mizza/ami1mmni 11
71h/
100W
8n
O
TOTAL IM
8n
WATT
a1IIII
M111111IIIIIII//111111
f 111111
111111
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311111
2
2
cc
002
I
1 II
NORMAL
RESPONSE 111111
FREQUENCY
schematic.
O.1
I
1
ON
BIAS
CIRCUIT
Ill,.11111MI
10KHz
IIIIiI
II
RUMBLE FILTER
H
Fig.
EMI
1!1315III10Hz
Mile"
IlhlIlIIII
IWATT
10K
S0W
11111
1W
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ow
20K
Hz
Fig. 6-One-watt frequency response into 8 ohms with THD
versus frequency and power. Note break at 100 Hz/10 kHz
in response curve.
AUDIO
60
www.americanradiohistory.com
AUGUST, 1975
ers about 230 to 250 watts into 8-ohm loads with a ±75 V
supply, whereas the B-1 puts out about 220 watts with a ±90
V supply. This simply means that the ultimate power conversion efficiency of V-FETs isn't as high as that of bipolar
devices.
Listening and Use Tests
Considerable time was spent a few months ago listening
to the B-1, mostly with a rather efficient, equalized speaker
array which concentrated attention on the lower portion of
the amp's power range. In this use, the Yamaha B-1 was
judged to be outstanding, definitely one of the best amps
heard up to that time. Some additional listening was done
then with Magnepan NG -2167F speakers, which are quite
inefficient and thus used a different portion of the Yamaha's
power range. It was this writer's opinion that the B-1 was as
good as, if not slightly better than any bipolar amp heard
until that time. It sounded a bit smoother and more hke a
very good tube amp than the hottest bipolar contender.
When it was driven into clipping, however, it didn't sound
as clean as the best bipolar amps.
A second B-1, this time with the optimal UC -1 control
unit, was obtained recently for this review and the amp
sounds as good as remembered. This reviewer has been
doing a great deal of listening evaluation recently with the
Stax SRX Mk -II electrostatic headphones, and the first thing
that was done with the second B-1 was to listen to it with the
Stax phones. The sound is extremely good, and the only
amps which have been judged superior with 'phones listening (and then not by a great margin) are a pair of modified
Marantz Model 9 tube units and a specially developed
Class -A transistor amp, neither of which are commercially
available.
The peak -responding meters are an absolute pleasure to
watch and use. It was noted that for equal outputs from a
common signal source, the B-1 would frequently read peak
powers from 5 to 10 times what was indicated by conventional meters on another solid-state amp, meters which
were otherwise correctly calibrated for RMS watts on a
steady-state sine-wave basis.
Measurements
The B-1 was first operated for one hour at one-third rated
power, 50 watts, into 8 -ohm loads, as per the FTC power
output regulation. The amp operated without thermal shutdown for the full hour required by the rule but did become
extremely hot, as was expected. Temperatures didn't exceed
100°C, however, since the thermal cutouts on the heat sinks
are set at that temperature.
Voltage gain into 8 -ohm loads was found to be 43.5X or
32.8 dB on direct input and varied from 5.5X to 43.0X, 14.8 to
32.7 dB, through the normal input with minimum to maximum settings of the front gain control. (Note that all measurements were made through the direct input unless otherwise noted.)
IM and 1 kHz THD versus power are shown in Fig. 5. THD
versus frequency and power are shown in Fig. 6, along with
one -watt frequency responses for direct, normal, and
rumble filter -in settings. One interesting observation was
that the high frequency response on normal inputs didn't
change much with the gain control settings due to their low
1K ohm value, in contrast to other units with higher impedance input volume controls.
Distortion for this unit is satisfactorily low and is not very
different from many current bipolar designs. In Fig. 6, the
10 -watt distortion is so close to the 50 -watt values that one
curve is shown for both. The 1 -watt distortion is buried in
noise at about 0.01% and climbs just above this value between 10 and 20 kHz. It was noticed that the amount of
higher order odd -harmonic distortion was rather depen-
Fig. 7-50 Hz square waves, 8 -ohm loads, 5 mS/cm. Top, 290
watts, 20 V/cm; bottom, 3.13 watts, 5 V/cm.
Fig.
8-10
kHz square waves, 5 V/cm, 20µS/cm. Top, 3.16
watts with 8 -ohm load; bottom, about 3 VA, 2µF load.
Fig.
AUDIO
9- Top
200 watts
20 kHz square wave 20 V/cm, 10 µS/cm about
with 8 -ohm load; bottom, 200 VA, 40 V rms, 0.15%
THD.
AUGUST, 1975
61
www.americanradiohistory.com
dent on output -stage idling current, and at least 400 mA,
Yamaha's design value, is required to keep these distortion
components negligibly low. Distortion measurements
through the input buffer amp on normal input were virtually the same as when bypassing this amp through the direct
inputs. 'Scope photos of amplifier responses are shown in
Figs. 7, 8 and 9 for various levels, waveforms, frequencies,
and loadings. Fig. 7 shows the response to low and high.level
50 -Hz square waves into an 8 -ohm resistive load, while Fig. 9
indicates the response to a 10 -kHz, relatively low-level
square wave with resistive and reactive loads. The ringing
with the 2µF load is typical of solid-state power amps and is
aused by an output RL buffing network that is used in the
B-1 as well as most other solid-state amps. Attempts at
'scope photos with much higher levels than 10 to 15 V p -p, 1
to 2µF loads, and fast square waves caused the protection
circuitry to activate. Some 20 kHz high -power square waves
are shown in Fig. 9. The overshoot for the square wave with
a resistive load starts at 15 to 20 V p -p and gets larger as the
level increases to the 80 V p -p shown. This amplifier, like
many others, is in a slewing condition when it changes state
from one level to another where the level changes represent a large fraction of the available output swing for a fast
step input. Large error signals are operating inside the amp
to cause it to go to the required new level as fast as it can.
The speed and manner that the output reaches the new level is determined by how the amp is compensated for stability and how fast these RC networks can be charged by the
available current in the stages where they are located. The
overshoot in the B-1 is its particular way of recovery from a
heavy slewing condition. Note, however, that the amp behaves essentially the same for a plus -to-minus as for a
minus -to -plus transition, which is a tribute to the symmetry
of the circuit. Several of the recently reviewed power amps
recover or reach their new levels with less or no overshoot.
However, it is not clear at this time whether this phonomenon has any particular sonic significance.
ELAC/Miracord 760 Automatic Turntable
are the same or nearly so, and the two models even look
Table I-Output Noise.
Bandwidth, Hz
Right, µV
Left, µV
Direct
20 to 20k
400 to 20k
Normal, Rumble Filter Out
20 to 20k
400 to 20k
Normal, Rumble Filter in
20 to 20k
400 to 20k
85
67
54
48
105
93
90
82
110
95
97
86
Output noise with shorted inputs is shown in Table as a
function of measurement bandwidth, direct or normal input, and rumble filter in or out. It can be seen that the input
amplifier used for normal inputs does add some noise, but
I
even the highest noise level of 110kV;is still some 110 dB below rated output of 150 watts into 8 ohms. These are truly
excellent output noise figures, indeed.
Power output at visual onset of clipping for 4-, 8-, and 16 ohm loads was 213, 220, and 144 watts, respectively.
Conclusions
The Yamaha B-1 amplifier is a fine piece of equipment and
has some very useful and interesting features. It is an ex-
cellent first implementation of a new technology, though it
is hoped that with time the price and complexity of V-FET
amps will decrease. This amplifier can be recommended as a
state-of-the-art device for those with the wherewithall to afBascom H. King
ford it.
Check No. 72 on Reader Service Card
alike:
On the right are three black pushbuttons for 7-, 10-, and
12 in. records, and a fourth button, a red one, activates the
Stop switch. At the left front is a three -position speed change switch, and the variable speed control is behind that
at the rear corner. An anti -skating control, calibrated for 1 to
6 grams, is at the right rear near the tone arm pivot.
The arm is counterbalanced, and its weight has a milled
plastic strip that meshes with the extension of a small control
knob (see Fig. 2). Adjustment is simplicity itself. All you do is
turn the knob until the arm (with cartridge attached) is balanced, then turn the control on the pressure dial (to the left
of the pivot) to read 2 grams or whatever figure is recommended by the cartridge maker. The anti -skating knob is
then set to the same figure. The plug-in head will take most
cartridges, and the metal mounting insert is adjustable for
MANUFACTURER'S SPECIFICATIONS
Speeds: 331/3 45, and 78 rpm. Wow and Flutter: 0.06%, and
0.07%, respectively. Rumble: -44 dB. Variable Speed: ± 3%
of nominal. Dimensions: 14 5h in. W. x 12 1 in. D.; base, 18 1
in. W. x 14 1/2 in. D. Price: $199.95.
The Miracord 760 is an updated but less expensive version
of the Model 50HII which we reviewed in May, 1972. It costs
$199.95, as compared to $249.95 for the 50HII. Surprisingly,
there are few differences, and those are minor. There are
strobe rings on the turntable instead of a neon -lit window,
no stylus brush is included, and the turntable platter does
and that's about
not have the beveled edge of the 50HII
all. Everything else, motor, changing mechanism, and arm,
-
Fig.
1-View of Arm mount.
AUDIO
62
www.americanradiohistory.com
AUGUST, 1975
quick, easy alignment. In front of the arm pivot is a long
cuing lever whose lifting height and lowering time are adjustable. A silicone-filled dashpot provides nice, slow lowering of the arm. The platter is quite heavy, weighing a bit
more than 6 1/4 lbs. There are two strobe scales, one for 60 Hz
and the other for 50 Hz.
As with the 50HI1 and other Miracords, the 760 has two
spindles: a short one for single play and a "Magic Wand" for
automatic play of up to 10 records. If the short spindle is inserted upside down the record will play continuously, a di -
Fig.
2-View underneath the turntable.
version that will probably have limited appeal, though it's
certainly useful for test engineers! The long spindle holds
the record on three small supports which drop each record
very gently. The silicone -damped mechanism of the arm inGTE -Sylvania
wheel.
Two phono cartridges were used for the tests: a Shure
V15 -III, and an Audio-technica AT20, a top -of -the -line CD -4
pickup. The first measurements were for wow and flutter,
and the figures came out 0.05% and 0.06% respectively,
slightly better than the specified 0.06% and 0.07%. The
rumble measurement was -54 dB (ARRL), also excellent for a
machine in this price range and notably better than the
maker's claim. Tone arm resonance measured with the
Shure cartridge was approximately 7 Hz, well below the critical region. As expected, the speed remained stable over the
range from 90 to 130 volts. The variable speed control gave
its specified variation of plus and minus 3%.
The stylus pressure scale is calibrated in grams from 0 to 6,
and it was found accurate within 5% above one gram. Arm
tracking error was about 0.5 degrees at the worst position.
The force needed to trigger the changing mechanism was
less than 0.5 grams, a far cry from the cumbersome old built like -a -battleship models of 20 years ago that used to need
ounces to start the cycling sequence. The arm's friction was
quite difficult to measure, being below 25 milligrams.
Cycling time was 16 seconds, a little slower than some other changers but not judged a disadvantage because the
records and pickup are handled so gently. The cuing control
worked smoothly and with precision, a pleasure to use. Special low -capacity cables are recommended for use with CD 4 cartridges; those supplied plug into sockets underneath so
changing them is an easy matter. In order to see the strobe
markings clearly the unit has to be placed near a fluorescent
light; no doubt some ingenious souls will mount a small
neon lamp nearby.
Summing up, the Model 50HI1 is still an excellent record
changer at $249.95, but at a saving of $50, the 760 is a real
George W. Tillet
bargain.
Check No. 73 on Reader Service Card
a 10 -in., high compliance woofer, while the upper frequencies are carried
by a 1 '/2 -in. dome tweeter. The cabinet is of moderate size
and is finished in walnut vinyl. The grille is sculptured brown
foam, held in place by grip fasteners on the front panel
board. The units are designed for either floor or shelf
mounting.
A recessed cavity on the rear of the enclosure contains the
speaker terminals and two toggle switches. The terminals
are of the 5 -way three-quarter inch spacing variety which allows ready hookup by spade lugs, twisted wire, or banana
plugs. The plastic insulated caps on these terminals are colored for polarity identification-red for positive and black
for negative. Printed next to the respective terminals are the
legends Pos and Neg, so the user should have no trouble
making proper connection.
Two toggle switches are mounted above the speaker terminals. One, a three -position switch, is labelled Mid Freq.
and has the marking Normal, Lo, and Hi in vertical -ascending order. This may be a good technical solution for a single
switch which changes the mid -frequency response in a twoway system, but it is less than perfect human engineering
since the lowest acoustic position is the center switch position. The other toggle switch is better. It is a two -position
High Freq. control marked Hi and Lo. Fortunately, the
acoustic effect of both controls is modest, so the user cannot
go far wrong.
by an acoustic suspension enclosure housing
Model AS210A
Speaker System
MANUFACTURER'S SPECIFICATIONS
System Type: Two-way acoustic suspension. Drivers: One
10 -in. (25.4 cm) woofer, one 1 '/-in. (3.8 cm) dome tweeter.
System Resonance: 42 Hz. Crossover Frequency: 1.5 kHz.
Impedance: 8 ohms nominal. Power Requirements: 10 watts
average. Size: 155/ein. W. x 11 '7a in. D. x 24 in. H. (39.7 x 29.8 x
61 cm). Weight: 51 lbs. (23.1 kg). Price: $99.95.
The Model AS201A speaker system, from GTE -Sylvania, is
a two -loudspeaker design. The bass frequencies are handled
AUDIO
sures that the fragile (and expensive) phono stylus is not
damaged as it lands on the record. The motor is a 4 -pole
asynchronous type which keeps the speed constant. Drive is
applied to the inside of the turntable rim by a rubber idler
63
AUGUST, 1975
www.americanradiohistory.com
The foam grille is massive -looking, but almost perfectly
transparent acoustically. It is held to the front panel with
Velcro fasteners, which allow it to be removed readily for
cleaning. A Sylvania logo is fastened to the foam front in one
special place with a Velcro fastener. As received, the logo
was mounted for vertical speaker placement with the woofer at the bottom of the panel and the rear panel control labels upright. If horizontal shelf mounting is desired, the logo
can be rotated ninety degrees, and refastened to stay upright. If you do this, be certain to make the logo appear in
the upper right corner so that the tweeter will be farthest
40
30
rn
3
MID FREQ SET TO HI
HIGH FREQ SET TO HI
O 20
IO
MID FREQ SET TO NORM
HIGH FREQ SET TO LO
IIIIIII
o
20
100
IK
I
I
IIII
-
10K
FREQUENCY -Hz
Fig.
1-Impedance.
+I5
/
+10
away from the shelf. This is to prevent shelf reflection from
the tweeter. The panel side of the grille is hollowed to fit the
slightly protruding speakers so there is only one way the
grille will attach properly. Because of the weight of the
AS210A only a very sturdy shelf should be used.
The AS -210-A is covered by a five-year warranty for any
part which fails in normal use during this period. The warranty also covers replacement labor or service charge for the
first two years.
Technical Measurements
The magnitude of load impedance which the AS210A
presents to an amplifier is shown in Fig. 1 for two positions
of the equalization controls. While there are six possible
equalization combinations, the two shown in Fig. 1 represent the extremes, so far as the load impedance is concerned.
When it comes to impedance there is one thing you can
depend upon-loudspeakers are never pure resistors. That
is no fault, they do not have to look like resistors. Yet, the recent fuming and fussing about the method of testing power
amplifiers for power has all but ignored the true load which
the amplifier must drive-the speaker. As this reviewer has
pointed out before, one can calculate a loudspeaker's complete impedance, magnitude, and phase angle, from measurement of impedance alone. That is why we show that
measurement. But perhaps a better service can be provided
if we also evaluate the loudspeaker as it might cause problems when used as a load for a power amplifier. Amplifiers
designed to drive pure resistances may experience stomach
aches when asked to drive actual loudspeakers at high level.
This is not the fault of the loudspeaker, but is certainly
caused by its presence.
20KHz
20Hz
+180
105
10
30
20
RESISTANCE
w
- OHMS
a
-
h
-
+90°
10
0°
15
Fig.
100
IK
FREQUENCY
2-Complex impedance plot.
- Hz
10K
4-One-meter, on axis phase response, corrected for
acoustic position of midrange driver.
Fig.
90
80
á<n
70
60
ree
MID FREQ-NORM
HIGH FREQ-LO
MID FREQ-NORM
HIGH FREQ-HI
I
III
30° LEFT
CH. POS.
90
30° RIGHT
mv
CH. POS.
80
I
J
o.
rn
70
60
20
100
IK
FREQUENCY
Fig.
3-One-meter,
one -watt input.
- Hz
IOK
20
100
IK
10K
FREQUENCY- Hz
on -axis anechoic amplitude response,
5-One-meter anechoic amplitude response for 30° off center listening positions.
Fig.
AUDIO AUGUST,
64
www.americanradiohistory.com
1975
Figure 2 is the measurement of the complex impedance of
the AS210A for the Mid Freq = Norm, High Freq = High
positions of equalization. The frequency range covered is
from 20 Hz to 20 kHz. Only a few frequency values are
marked on this plot since Fig. 1 shows the frequency characteristic for the same data measured as magnitude.
The lowest value of impedance presented by the AS210A
is slightly below 8 ohms, and is resistive. Two main resonances are shown, one of them is the characteristic resonance of a sealed enclosure (the large circular arc in Fig. 2)
which peaks here around 43 Hz. The other is a midrange
peak at 600 Hz. This speaker is resistive at four frequencies
between 20 Hz and 20 kHz. The worst reactance load at high
frequencies, where many inexpensive amplifiers experience
difficulty, is a capacitive reactance of only 11 degrees phase
angle near 1100 Hz. The worst reactive volt-ampere drive
near bass resonance should offer no problems to any reasonably well -designed amplifier. These plots show that the
AS210A offers no load problem.
One -meter on -axis anechoic frequency response is
shown in Fig. 3 for amplitude (SPL) and in Fig. 4 for phase.
The axial SPL is quite smooth. The low frequency response is
a textbook 12 dB -per -octave rolloff below 55 Hz. Some
crossover notching occurs at around 1100 Hz but the trend is
smooth up to an upper limit around 18 kHz.
The axial phase response reveals that the woofer and
tweeter are in phase at crossover with no sudden phase shift
to mar performance. The axial response is principally minimum -phase throughout the frequency range. Above 3 kHz
the tweeter has a 90 degree phase lag for this measurement.
Only one phase measurement is shown, and this is corrected for the average acoustic position in the range from
600 Hz to 3 kHz. The acoustic position from 3 kHz to 12 kHz
is such that the sound reaches the ear 0.1 millisecond earlier
than sound in the 600 to 3 kHz range. The sonic effect of this
arrival difference usually is to emphasize speech sibilants
-15dB
11111111111
1111111
Illll
RIIII,
1111,1i
..
1III
1111111
ON AXIS
1111II1a111iI.11 11'
111111118Ir2*fä111
B11IIIII1111II Minn
III
1111111
111
30° LEFT
CH. POS.
100
FRONTAL
AXIS
Illl11-
I
Fig.
MID FREQ
HIGH FREQ
-
-
HI
HI
8-Horizontal polar energy response.
10K
1K
TOP
FREQUENCY- Hz
Fig.
-LO
FREQ-LO
MID FREQ
HIGH
o
6-Three-meter room response-speaker on floor.
FRONT
I0dB
ON
i
AXIS
iNsIt
n
..\\1
30° LEFT
CH. POS.
Ill
100
1K
FREQUENCY
Fig.
-
10K
Hz
7-Three-meter room response-speaker
24 in.
above
Fig.
floor.
AUDIO
BOTTOM
9-Vertical polar energy response.
65
AUGUST, 1975
www.americanradiohistory.com
and crispen short -duration sounds. However the magnitude
of delay in this speaker on axis is so small as to be negligible.
There is a distinct off -axis effect that deserves some notice. The best frequency response occurs directly in front of
the AS210A. When the speakers are placed in a right channel and left channel stereo position, however, the anechoic
response is not as smooth, as can be seen in Fig. 5. With the
speaker rotated so that its axis falls to the right of the listener (right channel stereo position), the unit is distinctly non minimum phase. In the frequency range from 1100 Hz to
2100 Hz the 30-degree right channel position has a non minimum phase transition of 1440 acoustical degrees lag.
Even a 10 -degree angle offset from the on -axis position provides a 720 -degree acoustic phase transition. This indicates
that the best sound will be obtained with the speakers angled directly toward the listening position.
The three -meter room response is shown in Figs. 6 and 7.
These measurements are the Fourier transform of the first 13
milliseconds of the loudspeaker's impulse response. They
show the characteristic timbre for "early" sound in a normal
listening situation.
The listening test revealed that an off-floor speaker position, as suggested in the instructions, provided more accurate sound than floor mounting. Figure 6 shows the response for floor mounting flat against a back wall. The data
of Fig. 7 shows the response with the AS210A raised 24 inches off the floor, placing the center of the speaker at ear level, approximately one meter above the floor. The off -floor
response may be seen to be distinctly superior. And as in the
anechoic measurements, the on -axis response is better than
that off -axis. definitely recommend rotating these speakers
in toward the listening area. The equalization used for all of
these measurements was Normal for mid -frequency and
High for high -frequency switch positions.
The polar energy response is given in Fig. 8 for the horizontal direction and in Fig. 9 for the vertical direction. Two
extreme equalizations were used for the polar tests. In one
case both mid -frequency and high -frequency switches were
set to Low, and in the other both were set to High. It is obvious from Fig. 8 that there is a distinct left -channel sound
superiority that verifies the anechoic and room test measurements. This measurement shows that a substantial
amount of sound will be reflected off the back wall if the
I
10
E2 -2n0
E1
A3'2nd
A2
2nOt
E4
-3rd
tortion, though not spectacularly low, stays at quite acceptably low levels, generally below 1% through the usual listening range.
Intermodulation of 440 Hz by 41 Hz is shown in Fig. 11 as a
function of drive level. There are about equal amounts of
phase and amplitude modulation on A4 caused by El. At 10
watts the amplitude modulation is 4°/o peak -to -peak and the
phase modulation is 6 degrees peak -to -peak. At 40 watts
there is 8% amplitude modulation and 10 degrees phase
modulation. These are both principally 41 Hz modulations.
In the crescendo-handling test, incoherent noise of 80
volts peak -to -peak magnitude caused a one-half dB drop on
a very low level A4 inner musical voice while barely suppressing a middle C voice. It can be concluded that applause
and hand claps will not cause significant modulation of low
level musical passages when the AS210A is driven within its
power rating. Both A2 (110 Hz) and middle C (262 Hz) are
one-half dB softer at 20 watt drive level than they should be
based on the acoustic gain of each at the 0.1 watt drive level.
Sudden loud passages may therefore cause a tiny lateral
spread of musical voices in the stereo image for those left of -center or right -of -center sounds which have more of
their energy in one channel. This effect is virtually nonexistent below 1 watt and at normal listening levels.
The energy -time curve of Fig. 12 is very good for a speaker
in this price range. This is the envelope of the impulse response computed for a one -meter on -axis position. The major sound energy arrives at 3.0 milliseconds, with very small
reverberant and diffractive scattering arriving after that
time. Integration of this data reveals that 95 percent of the
sound energy arrives within 3.1 milliseconds and 99 percent
arrives within 3.4 milliseconds. The only late straggler (arriving at 4.6 milliseconds) is due to enclosure -boundary diffraction, and that is almost 30 dB down. The dominant frequency for the first sound arrival is in the 10 kHz range.
Therefore record ticks and scratch might be accentuated to
a small extent.
Listening Test
Two listening positions were chosen for auditioning the
E63rdf
A5
82=3rd
speakers are rotated toward the listening area while placed
against that back wall. In some listening rooms this might
give a stage -filling spread of sound pleasing to some ears,
but not so realistic to others. To minimize this effect it may
be necessary to experiment with the speakers pulled away
from the wall. The broad horizontal dispersion of frequencies indicates that large reflecting objects, such as book
cases, should not be placed next to the AS210A if they extend past the front of the enclosure.
Harmonic distortion for the musical tones of Ei(41.2 Hz),
A2 (110 Hz), and A4 (440 Hz) is shown in Fig. 10. This dis-
E1A4
AS210A. In one position the speakers were placed flat
against a wall and raised off the floor so as to be nearly ear
9
A2
8
7
0.1
6
5
001
0.I
loo
10
I
I
1
70
80
90
4
WATTS
3
SPL E141.2Fez
100
2
I
80
80
1
90lI1
1
1
90
100
1
1I
'
SPL A2.110Hz
SPL
`
A4.440 Hz
Fig. 10-Harmonic distortion for musical tones El (41 Hz), A2
(110 Hz), and A4 (440 Hz).
66
0
0
1
POWER
Fig.
11-Distortion of
- WATTS
10
A4 (440 Hz) by El (41 Hz), mixed 1:1.
AUDIO AUGUST,
1975
height for a listener who is seated. In the other listening position the units were placed on the floor, slightly away from
the back wall. The stereo listening angle was about 60 degrees for both positions.
From the standpoint of overall sonic bálance of the midrange and upper frequencies the better of the two positions
is the raised, wall -mounted location. However the bass frequencies appeared to my ears to be too strong when the
which tends to overwhelm the midrange frequencies even
with the mid frequency equalization in the Hi position. The
very highest frequencies, carried by the tweeter, can be
brought up to the level of the bass frequencies with the
tweeter control in Hi. Even with a Lo tweeter control setting
on the AS210A and conventional tone control boost, the
midrange appears to lack punch.
The bass heaviness of this system, coupled with the robust
high frequency response, may constitute sound that is pleasing to a great many listeners. am not one of them. must
admit that classic pipe organ sounds very good on this system and creates a good, space -filling illusion. Vocals and
percussion bass instruments did not appear as accurate to
I
I
my ear.
Stereo localization
20
-
30
- 40
30
'
35
-
TIME
Fig.
is moderately good with this system,
slight tendency for lateral spreading of some stereo
instruments. For those instruments which contain most or all
of their energy in the frequency range of the tweeter, the
sound is darn good. The tweeter is, in fact, the star performer in this loudspeaker system. The articulation and transient
performance of the tweeter is excellent.
The AS210A is not a speaker system that can recommend
as a primary stereo system for a very large room. There are,
however, several applications where the sound qualities of
this speaker can be put to good use. One is as the important
rear speakers of a quadraphonic instalation. The distribution
of sound energy may complement that of some of the higher quality systems one might use for the front. A second application is that of low-cost stereo speakers for a very small
room, as in many college dormitories, where the bass response of many systems often sound anemic. The AS210A
Richard C. Heyser
should shine in that environment.
with
4.0
-
l-. J45
a
I
T1
50
MILLISECONDS
12-Energy-time response.
speakers were against the wall. The floor position reduced
this bass dominance but did so at the expense of midrange
clarity. The AS210A, in my opinion, needs all the midrange
level you can get from conventional tone control equalization. This is because of the strong bass (200 Hz and below)
Check No. 74 on Reader Service Card
flush -mounted Off, On, Dolby, and Cr02 push-button
switches and status lights are located at the left end. Immediately to the right are the slide -type record -level controls.
Adjusting the control's narrow -bar knob moves a sheet of
transparent plastic with a horizontal green line which indicates level on the scale printed white on a black background under the sliding plastic.
The level meters are located in the middle of the deck,
with a record indicator just in front. The meter needles and
the normal -level scales are white, with high levels in red, all
against a black background. Illumination from the back of
the meters provides additional contrast, and the tapered
shape of the needles aids in reading varying levels. To the
right of the meters is the cassette well, which has a note on
Bang & Olufsen Model 2200
Cassette Deck
MANUFACTURER'S SPECIFICATIONS
Frequency Response: 30 Hz to 14.5 kHz. Signal /Noise Ratio:
At least 52 dB with CrO2tape; at least 61 dB with Dolby. Input Sensitivity: Line, 0.2 V at 2.2M ohms; mike, 0.1 mV at
1000 ohms. Wow and Flutter: Less than 0.2%. Erase: At least
70 dB. Output Level: Line, 660 mV. Speed Deviation: Within
1.5%. Fast Forward or Rewind Time: 70 sec., C-60. Dimensions: 19.7 in. W. x 2.9 in. H. x 9.1 in D. Weight: 12.6 lbs.
Price: $460.00.
The Bang & Olufsen 2200 cassette recorder has a clean
and uncluttered appearance, with a flat top panel in black
finish with real wood skirting on the sides and front. The
nU1G711
DIN (STANDARD TAPE)
i
DIN (CHROME TAPE)
5d8
4
30
-
100
Fig.
1
-
AUDIO
Fig. 2
Rear view of the B&O
BE -2200.
-
10K
IK
FREQUENCY
-
Hz
Playback from DIN test tapes; top, standard, and
bottom, chrome.
AUGUST, 1975
67
www.americanradiohistory.com
equipped with high -density ferrite heads. Tape is inserted into the tray attached to the cover and positioned by pushing down on the cover. In front of
the well are the Eject, Stop, Rewind, Play, Fast Forward,
Record, and Pause piano -style keys.
Next to the cassette well and at the right end of the deck
are the stereo phone jack and a DIN microphone jack.
These are recessed below the top of the panel and can be
covered by a small sliding panel with a bar knob. An added
convenience is the inclusion of a Stereo/Mono switch for
the microphone, facilitating feeding both channels with just
one mike. Behind the well are the counter with its Reset
button and the memory On/Off switch.
Line input and output connections are made at the back
with a 5 -pin DIN socket. B & O provides an adapter cable
with four phono jacks to facilitate connections to the typical
American system. There is also a DIN socket with input/output levels to match European radio standards.
Plugging into the microphone jack disconnects the line inits cover that the machine is
puts.
Performance
The 2200 deck performed very smoothly in all of its
tests, meeting all of its specifications. Playback response
with a standard DIN tape was within 2 dB from 31.5 Hz to 6.3
kHz, but with a droop of almost 5 dB at 10 kHz. Playback response with the Cr02 DIN tape was better at the high end,
with a droop of just 2.4 dB at 12.5 kHz. (See Fig. 2.) The
record/playback response curves of this unit were particu-
- --
TDK CHROME
W/0 DOLBY
WITH DOLBY
5dB
30
00
-
IOK
IK
FREQUENCY
20K
larly noteworthy because of their flatness. Using Capitol
Music tape with Dolby out, shown in Fig. 3, the response
curve was flat within a fraction of a dB from 50 Hz to almost
10 kHz at -20 VU. At this level, the 3 -dB -down points were at
26 Hz and 16.0 kHz, superior to the 30 Hz to 14.5 kHz specification. Similar flat responses were obtained with BASF LH
and Memorex MRX2. The headroom at 0 VU was limited to
6.1 to 7.1 kHz with these tapes, with low frequency droop
also in evidence. With the fast -response meters provided,
this limitation (shown when using constant -level test signals)
is more apparent than would be the case in actual practice.
One of the benefits associated with the flat response of
these low -noise tapes was that any mistracking in the Dolby
circuits was minimized.
Performance with two ferrichrome tapes, Scotch Classic
and Meriton, was less satisfactory overall. Although the
headroom at 0 VU was better than the low -noise tapes,
there was rising high -frequency response at -20 VU in Dolby
mode.
The Dolby -out record/play responses with TDK KR
chrome tape showed good headroom at 0 VU, within 3 dB
out to 15.0 kHz at -20 VU and generally flat at both levels.
With Dolby in, the response was quite acceptable at -20 VU
with elevations of 2 dB at 100 Hz and 6 kHz.
The harmonic distortion of the 2200 over a range of input levels (1 kHz) was determined using a spectrum analyzer. In this way distortion products were measured at low
input levels where noise would normally cause higher, erroneous readings with commonly -used distortion meters.
BASF LH, Capitol Music, and Memorex MRX2 showed the
lowest total distortion over the test range, reaching 3 percent distortion at about +3.5 VU. The ferrichrome and Cr02
tapes reached the same distortion level at +1 VU. The levels
of the harmonics generated with a 0 VU input signal over a
frequency span of 30 Hz to 10 kHz were also measured. The
analyzer showed that the dropping figures for distortion
from 2 kHz to 5 kHz were the result of harmonics being
eliminated by tape saturation effects. Also revealed was the
fact that the distortion products at 10 kHz were actually
forms of subharmonics, perhaps beat notes with the bias oscillator. The average A -weighted signal-to-noise ratio for
three low -noise tapes was almost 54 dB relative to 0 VU,
about 57 dB relative to a 3 percent distortion reference.
-Hz
Record/Playback response, Capitol Music tape,
Fig. 3
with and without Dolby, recorded at Zero VU, and at -20
6
/
VU.
5
4.5
4.0
4
MEMOREX
----- -
3.5
CAPITOL
BASF
3.0
BASF
3
BASF
CAPITOL
MEMOREX
2.5
2.0
2
1.5
1.0
.05
IO
-
100
IK
FREQUENCY
-
I0K
Hz
Fig. 4
Harmonic distortion at 1 kHz, three tapes, with Dolby. Variations were so small (less than 1% generally), that
curves could not be shown separately.
68
0
-2
Fig. 5
-
0
+2
+I
LEVEL
+3
+4
+5
-VU
Distortion versus frequency for three tapes.
AUDIO AUGUST,
1975
With Dolby in, the average signal/noise ratio reached 61 dB
and 64.6 dB. Results with ferrichrome and chromium dioxide tapes were not as good, though the TDK KR did meet
the B & O specification of over 52 dB without Dolby and
over 61 dB with Dolby. The 3 percent distortion reference is
quite appropriate for this deck, with its fast -response metering. These meters are frequency dependent, with greater
deflection at the frequency extremes, about +5 dB at 40 Hz
and 10 kHz, a good idea in most respects.
The spectrum analyzer was needed to verify that the unit
did indeed surpass its 70 -dB erase specification, actually
doing at least 1 dB better without Dolby, and at least 6 dB
better in Dolby mode. Crosstalk between stereo channels
was -28 dB, acceptable although a bit high, and more than 60
dB down between adjacent channels of opposite -play direction. The best flutter figure obtained was 0.08%, and 0.19%
was the average for DIN weighting, within the specified
0.20%. Average rewind time was 65 seconds, well within the
70 -second specification. Tape speed was 0.6% fast with 120 V
a.c. power.
The drive signal input to the headphone jack was 775 mV
across 8 ohms, giving good listening volume with phones of
various sensitivities and impedances, a desirable feature.
Microphone input sensitivity of 0.094 mV was slightly better
than the specified 0.1 mV. Line sensitivity was 107 mV, noticeably better than the specified 200 mV.
The output for 0 VU indication in playback was 700 mV
---
5dB
W/0
DOLBY
WITH DOLBY
o
$
-
10
- 20
10
100
IK
10K
FREQUENCY - Hz
-
Record/Playback response, TDK KR (chrome) tape,
Fig. 6
with and without Dolby.
Addendum
SAE
MK-IIICM Amplifier
It was discovered recently that two inaccurate 'scope
photos appeared in the January, 1975 review of the SAE
Mk-IIICM power amplifier. Specifically the upper trace
of Fig. 7 on page 63, showing low frequency tilt at high
power, and the upper trace of Fig. 10 on page 64, showing an exponential leading edge on a high power 20 kHz square wave, are in error.
The square -wave and pulse generators used for these
photos both have a d.c. component in their output
equal to one half of the peak -to -peak signal output. In
the Mk-IIICM design,there are two back-to-backdiodes
from the signal input to the overall shunt loop -feedback resistor. The purpose of these diodes is to reduce
the amount of internal overdrive signal when the amplifier is driven heavily into clipping. With a d.c. component on the input square wave, one of these diodes
AUDIO AUGUST,
compared to the specified 660 mV. With no output controls,
the level played back was dependent upon the record sensitivity of the tape used. There is no output from the recorder
line output when in Record mode, although the headphone
jack is driven. The dynamic action of the meters was checked by feeding in a single -cycle tone burst of the same amplitude as would provide a 0 VU indication if it were continuous. The meters reached -3 dB with a 705 Hz burst and -1 dB
with a 345 Hz burst which have 1.4 and 3 millisecond periods, respectively.
In -Use Tests
The meters of the B & 0 2200 are superior to many others
classified as peak responding. The attack time is visually
well correlated to the audible character of the music. The
decay time is well chosen so there is no sense of a lagging indication of level. The record -level controls slide smoothly
with no binding.
The tape motion controls responded to a light touch, continually conveying the impression of quality construction. A
minor criticism is that the solid black of the memory On -Off
switch against the black background of the top panel made
it difficult to be certain of the status of this function. A lightcolored band around the button would be an aid.
The instruction book is not lengthy or detailed, but adequate. A schematic is supplied, of excellent quality with
component values and functions clearly identified. On the
back of the schematic, two board layouts pinpoint the location and function of all the adjustment pots. This information will be of great value to owner or serviceman in peaking the performance to match a particular tape. Access to
most of the circuitry is gained by removing four bottom
screws. High quality workmanship and components are evident throughout the machine.
Listening tests were performed by making copies, both
with and without Dolby, of the October Excursion and
Epiphany movements of Respighi's Feste Romana. Perhaps
the best indication of the quality of the playback with various tapes is that no change could be heard between the
dubs and the original. On the other hand, the ferrichrome
tapes gave the plucked mandolin a slightly wiry sound, and
their poorer noise performance was apparent. The chromium dioxide tapes failed to give improved performance
over the low -noise varieties, which proved to be very well
Howard A. Roberson
matched to this cassette deck.
Check No. 75 on Reader Service Card
conducts and, by rectification, upsets or influences the
fed -back output signal, thus causing low -frequency tilt
at higher output powers (greater input voltages) and an
exponential shape on the rise time of a large, fast step input change.
With the d.c. component removed with a suitable external series capacitor and shunt resistor with a very
long time constant, which is representative of normal
use with preamp outputs, the high-level 50 -Hz square
wave would have virtually no tilt, and the large fast step input response would be more linear or straight sided,
and have a full -power rise time closer to 3 or 4µS than
the 6 to 7µS indicated in the review.
The use of these signal generators having the d.c.
component generally does not affect other input a.c.
coupled amps which don't have input limiting diodes
used in this manner, and the 'scope photos shown with
those reviews are correct.
1975
69
www.americanradiohistory.com
The Column
J
Fred DeVan
Dixie Rock: Wet Willie
Capricorn CP-0149, stereo, $6.98
Keep On Smilin': Wet Willie
Capricorn CP-0128, stereo, $6.98
Wet Willie, Capricorn's brash,
spunky, "best of the bar bands," has
made the most perfunctory disc possible on Dixie Rock. It's dry, plodding,
and pedantic, by Wet Willie standards. This band has put out such exciting, driving, gutsy performances in
the past that this record is disappointing. It's as if old age or road fever had
struck them comatose. All the thrill
got from picking up the album was
dashed by the merely better -than standard boogie music it contained.
Better than standard, but not the Wet
Willie they showed on their earlier album, Keep On Smilin'. That one was
so good that nothing could surpass it.
Dixie Rock sounds like an uninspired
quickie that no one cared about. Even
though the band has so much talent,
they succeed in making the inevitable
so-so album that plagues every good
group occasionally. Wet Willie is not a
mediocre band, so let's keep on smilin' and talk about Keep On Smilin'.
That one was dynamite-presented
by the best sock -em "bar" band in the
South. Uninhibited, vital, colorful,
skillful, contemporary rock. Boy, what
I
70
band that was-and still is. I'm sure a
little rest and reflection will help them
vindicate themselves for the lower
quality of Dixie Rock. The stompin',
spunky, ultimate boogie style that's
their trademark really came together
on Keep On Smilin'. The strong vocals
that always fit, and funky horns that
fly, really set them apart from other
a
groups. These qualities exist on all
their albums, but Keep On Smilin' is
their best recorded performance.
Country Side of Life, Keep On Smilin', and Soul Sister are among the finest tracks to come out of the Macon,
Ga. home base of Capricorn Records,
and location of their fantastic studio.
It's such a good studio that it's probably easy to be lazy and laid back when
working there. Alabama is a lovely,
wistful love -anticipation ballad that is
far superior to the usual change -of pace, slow tune most bands throw
into their act. The basic pace of their
rhythm section is a laid-back, rolling
and bopping masterpiece. And very
Southern. However, they are never
sloppy. Even with boogie lyrics, the
"Willietts" tighten everything up by
raising the excitement level with
amazing vocal interplay and strength.
The whole band wails, but unlike the
Boston style (J. Giles), the vocals are
allowed to come up front.
A lot of this is accredited to Tom
Dowd, the band's producer. All the
good things about sound and performance excitement that Dowd forgot when he did Eric Clapton's 461,
are deftly applied to Keep On Smilin!
When Tom Dowd produces a good
record, he delivers a great one. The
sound is as gutsy as the band and the
material. Clean and open.
The delineation between instruments and voices is faultlessly clear,
but the pressing have is one from the
height of the vinyl shortage madness
and is junk. Somehow through the
slush and gravel, the wizard of Warner manages a nearly -acceptable
record. don't think a current pressing of the album would be so bad. If
you do get one that's excessively
noisy, drop a note to the nice understanding folks in Burbank. That's the
only way they will be able to find
those evil old oil -crisis -caused discs.
Keep on Smilin'.
I
I
Dixie Rock
Sound: B+
Keep On Smilin'
Sound: A?
AUDIO
Performance: C
Performahce: A+
AUGUST, 1975
Reality: Monk Montgomery
Philadelphia Int'I. KZ33153
Stereo,
$4.95.
a refreshing treat this record
After all the thundering bass players with their 16 -foot high amplifier speakers going thump, whump, along
comes Monk Montgomery with the
electric (Fender) bass as a lead voice!
A bass player up front-playing melodies, chromatic structures, and obligattoes-not just guitar chords. And
playing warm and light! A Fender bass
behaving like a tenor sax, a trombone, a cello, a scatting male voice.
What
is!
Low and sensual, rich and sensitive.
Monk's brother Wes was a gifted guitarist who died at an early age several
years ago. Monk is one of the few
musicians who didn't scoff at the Fender bass in the early Fifties when it was
first produced. At that time he was
with the Lionel Hampton big band,
and he was one of the very first acoustic bass players to adopt the electric.
He not only used it, but almost alone
lifted it out of its toy novelty class to
make it the most used of all electrical
musical instruments. We have all had
our musical orientation changed by
the existence of this instrument.
Without it much of the music we hear
today would be impossible.
In addition to my formal training on
the acoustic (double) bass, and experience playing trombone, euponium and tuba, own and play an electric (Fender Precision) bass. Thus,
have some understanding of how unusual are the things Monk Montgomery does with his instrument. He
I
I
master!
Specifically, on I Love You, Camille
(written by Bill Cosby) he glides
through the theme in two-part harmony with Ron Feuer on Hammond
organ to create sound so haunting
and lovely that it just stopped me in
my tracks. He moves over t1e full
range of "his" instrument with astonishing ease and aplomb. One would
never guess that these sounds are
coming from the same instrument
that growls and roars behind the likes
of Brownsville Station, or any other of
the hundreds of practitioners of bad
taste who pollute the air with bad
rock and roll.
Monk Montgomery doesn't play
rock. He doesn't play jazz. He doesn't
play anything that we have a name
for, but he does play taste. He is a real
musician-a true virtuoso. Perhaps
undercan't be objective because
stand the technical problems presented by what he's doing. Yet as write
this realize I'm listening to nothing
less than perfect musical expression
and performance. If you've ever
played any instrument, even a kazoo,
is a
I
I
I
I
AUDIO AUGUST,
you will know the first time you hear
him that something extraordinary is
going on.
What it is or how it is done is less
important than being aware that this
performance is a masterpiece. If rearranged and restructured it could be
called Concerto for Electric Bass and
the Philly Sound. If hyped up and
roughened, it would have a dozen
descriptions from as many press
agents. But leave it as it is: just call it
wonderful, pleasant, contemporary
music at its finest.
Since the label is Philadelphia International we expect quality and
class. Perfect recording is therefore
taken for granted. The sound of Philly
is one of the most sought-after in
popular music today. It is universal
and in one way or another appeals to
almost everybody. But this disc is
above even that elevated standard.
I've listened to every record thus far
released by PIR, Inc., and I've yet to
find a bad one. They issue many
different kinds of music, but the Philly
quality is always there. If America has
an equivalent to ECM (of Germany) it
is the Sound of Philadelphia (i.e. PIR).
Reality is a departure only in the
material presented, and it's one of the
best efforts of the energetic young
musicians who run the company.
They've promised 17 discs in the next
two or three months, so plan to take
a lorg look at PIR soon.
Right now, I'm going to put on
Monk Montgomery's Reality one
more time, grab my Fender bass, sit in
the center of my listening room and
get totally carried away.
love this
record!
I
I
Philadelphia International Records
Discography
Listed here are some of the best re-
Some of
your music is
missing.
... Unless you have adequate
amplifier power. Some of the
most dramatic music in your
record or tape collection is being
clipped away if your amplifier
doesn't have the power to handle
difficult passages at realistic
listening levels.
That's the raison d'etre of the
Phase Linear 700B Amplifier. It
has the highest power, widest
frequency response, lowest
distortion of any stereo amplifier
in the world. It may be what you
need to restore your missing
music. Ask your dealer for a
demonstration.
cords issued by PIR:
War of the Gods, Billy Paul, KZ32409;
Half and Half, Cleveland Eaton,
KL32077; Yellow Sunshine, Yellow
Sunshine, KZ32405; Spiritual Concept, Spiritual Concept, KZ32404; and
three by the O'Jays: live in London,
KL32953, Back Stabbers, KZ31712, Ship
Ahoy, KZ32408.
Sound: A
Performance: A
Light of Worlds: Kool & the Gang
De -Cite 2014, stereo, $6.98.
For quite some years Kool & the
Gang tried to get a break playing a
jazz -affected kind of barroom blues.
Struggling for all they were worth,
they spiked their product with a heavy
dose of tight 4/4 dance rhythms, and
played jazz around the big beat. At
first they had to play funky in order to
71
1975
www.americanradiohistory.com
700-.iJ
THE POWERFUL DIFFERENCE
PHASE LINEAR CORPORATION,
P.
O. BOX 1335,
LYNNWOOD, WASHINGTON 98036
Check No. 24 on Reader Service Card
eat, and they played their jazz around
bars in the Jersey City area in the mid Sixties where no one was listening.
As time went by, the seven -man
band got more and more affected by
the funky stuff while attempting to
deny their jazz roots. Out of the necessity to eat and a healthy dose of
frustration, a blending of the two
seemingly conflicting forms became
the musical direction of the band.
They changed their name from The
Jazziacs and made their first album in
1969, but after seven albums and five
more years, they were still little
known.
After their seventh album, Kool
Jazz, (De -Lite DEP 4001) they decided
to do a commercial, repetitious little
thing called Jungle Boogie, which hit
#1 on the R&B charts. It sold scads of
45 doughnuts and my daughter Yvette
(then 11) drove me nearly nuts playing it. hated that record, but heard
something that made me curious. She
conned me into watch.ng them on
I
I
Which speaker looks like
it sounds the best.
television and what saw looked to
me like a jazz band that had sold out.
We discovered the group's previous,
more rewarding albums, and suddenly Jungle Boogie fit into a much
bigger scenario. Now she and both
listen to all the Kool & Gang we can
find.
Today the group is an unqualified
success with three gold records in six
months, all out of album number 8,
Wild And Peaceful (Delight DEP 2013).
Now we have number 9, Light Of
Worlds exibiting a further catharsis of
the band. Here they show the development of their years of hard work.
This album is not a departure from
the format that made them happen. A
little James Brown thumping, a bit of
Herbie Hancock keyboards, a little
Stanley Turrentine sax blowing, and a
lot of Kool & The Gang. This music is
jazz stepping into rhythm & blues, not
adapted R&B. The music stretches
from easy listening to hard thumping
on one disc. This mix probably limits
their audience acceptance, since if
you go to hear them for one style you
get the other styles whether you like
them or not. This Light of Worlds
appears spotty because of the wide
range of subject matter it covers.
The whole record is quite enjoyable and easy to listen to often. Frankly,
hope they continue to confuse
their fans, cause it's seldom you get
musicians who steadfastly follow their
own instincts and are not swayed by
success into starving the audience.
Why should everything that they do
after a hit be reminiscent of that hit?
The sound is good, at times exceptional. Mastering and pressing are excellent, with no noise, pops, or crackles, even in the very light keyboard
passages which supply a delicate
dimension. The engineering is rich
and detailed. The synthesized quad
sound is superb with excellent instrument location in either SQ or QS
mode. With all their texture a true
quad album would indeed be a
delight, but there is little wrong with
I
I
I
EPI 110
HARTLEY ZODIAC '75
ADVENT -"LARGER-
Most audio experts agree: the bigger the box. the
bigger the sound. A bigger cabinet means better bass
response.
So when we designed the Hartley Zodiac '75 to
compete with other popular bookshelf speakers. we made
it bigger. By using only a few more inches of your shelf
or floor. we give you Twenty-five to Sixty percent more
cabinet than our competition. And more cabinet means
bigger sound.
Our cabinet is only part of a two-way speaker system
that gives clear. sharp response from 30 to 25.000 cycles.
We build our Zodiac speakers in asymmetrically matched
pairs for better sound dispersion. We use only top
grade walnut veneers and a unique acoustic foam grille.
And we back them with a Five-year warranty. Five -years.
not Two or Three.
We do all of this for about the same price as our
competition. You see. we believe when you spend your
hard earned dollars for speakers. you deserve the
biggest sound your money can buy.
Hartley Products Corporation
56 North Summit Street. Tenafly. New Jersey 07670
(201) 871-3442
Hartley Canada Ltd., St. Hyacinthe, Quebec Coral Audio Corp.,
Tokyo -Osaka, Japan Royal Asia Ltd., Taipei, Taiwan Interdyn,
Melbourne, Australia.
this stereo disc.
Kool & The Gang are a pleasure to
explore. It is obvious that there is a lot
to be heard from them in the future.
Fortunately, while we await their next
offering, we have nine already to
nicely fill the time.
Sound: A
Performance: A+
Nightbirds: LaBelle
Epic KE-33075, stereo, $5.98
Patti LaBelle is an almost -middleaged singer who has been around for
72
AUDIO
AUGUST, 1975
long as I care to remember. She is a
chameleon who changes her style
abruptly, yet successfully. This is a
whole new thing for her, and it's her
best yet. Compared to what she has
done before it's almost non-commercial, yet it will probably be her biggest
as
success ever. It has broad appeal that
makes it work, but it's not the instant
Top -40 thing she used to do. In fact,
the most interesting aspect is that it is
effort, unique in
a very unusual
many ways, both musically and
conceptually.
Its stellar tune is Lady Marmalade, a
wild, sexy song, with a feminist slant
on it all (but you have to be bi -lingual
to get the whole message) sung in English and French, by three strong
Black females.
On Don't Bring Me Down, Night birds, What Can I Do For You, and All
Girl Band, LaBelle, Sarah Dash, and
Nona Hendry romp and roll through
their material like the unisex Valkyries
from 1975 that their fans think they
are. Maybe they are. I don't think Allen Toussaint has a Richard Wagner
fixation, or any other personality
problem, but he has produced one
hell of a record with this band and
these three supercharged raunchand-roll superwomen. Seen up close
they look completely out of character
until they start to sing.
LaBelle is not everybody's trip, but
it's definitely an interesting one.
Nightbirds has amazing lyrics which
could only come from someone with
a mature point of view. LaBelle are
not kids (nor are they like Stella Dallas) but they are having fun, as always.
Their band is splendid. Maybe the
horns stumble around a bit, and the
sound could be better. I am not sure
what it is, but it's not Allen Toussaint's
usual crystal-clear sound. There are
also a few spots where I thought I
could hear some distortion. Nothing
vital, however. Curious, successful,
refreshing.
Performance: A
Sound: B
New Skin For The Old Ceremony:
Leonard Cohen
Columbia KC -33167, stereo, $5.98
Canadian poet -singer Leonard Cohen has a new record out. For Leonard Cohen fans, it probably is as good
as, or better than, his previous one.
But I am not at all a Leonard Cohen
fan. spent a lot of time trying to accept his own particular presentation
of words. Possibly my bias comes from
the anti -music quality of his performance. Like Rod McKuen, the words
are all that's really of any importance
to him. His standard lethargy pervades
I
AUDIO AUGUST,
1975
73
this disc. For all his possible virtues, he
bores me so much that I didn't hear
the whole album. Maybe someday
I
will.
To all Leonard Cohen's special
friends, am sure New Skin For The
Old Ceremony will be welcome. It's
probably better than realize.
Performance: B
Sound: B
I
I
The Baker-Gurvitz Army
Janus JXS 7015, stereo, $6.98.
A must for Ginger Baker followers,
like me. It's spotty, sometimes good,
sometimes spectacular, sometimes
frustrating. The sound also varies, and
is a bit sloppy. The production is casual, at best. As usual, a few spots of fine
Ginger Baker flash. Cream, Blind
Faith, and The Ginger Baker Air Force
still remain the best of Ginger Baker!
Try this one-you may not love it, but
it's worth trying.
Performance: B
Sound: A
(Continued on page 79)
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AUDIO
AUGUST, 1975
(Continued from page 73)
Physical
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No matter that I have heard only
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only under surreptitious circumstances. Led Zepplin's new album
continues their incredible money
making. Why shouldn't they make
money? They have never made a
record that wasn't worth three of
most other groups.
House of the Holy was phenomenal. Anything that sustains Robert
Plant's vocal and visceral exercises has
to be phenomenal. Jimmy Page's guitar is a phenomenon (one of the
tracks I heard had one of his acoustic
solos). John Bonham has more
strength and stamina than a whole or-
chestra, the most unpredictable
drummer in the world. John Paul is
like a musical genius in an instrument
store. They are Led Zep, and Led Zep
is Rock and Roll perfection. Only they
are palatable when you want to hear
Led Zepplin music. No one else can
do or does what they do. have never
heard of a Led Zepplin copy group,
nor anyone else grifting from their
most individual, distinctive brand of
music. No one else even comes close.
You don't have to understand or like
them to be blown away by the likes of
Stairway to Heaven, or Ramble On.
I've seen hard-headed mid -fifties
Jazz freaks driven into delerium by
the fact that something done by Zepplin fascinates them. But that's normal. Led Zepplin does something tascinating to someone all the time.
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AUDIO
AUGUST, 1975
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Distributed In Canada by:
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79
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www.americanradiohistory.com
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Canby's Capsules
Edward Tatnall Canby
Chopin: Vars. on Mozart's "Li ci
darem la mano" (Don Giovanni), Op.
2; Fantasy on Polish Airs, Op. 13; Andante Spianato and Gnde. Polonaise
brillante, Op. 22. Claudio Arrau;
London Philharmonic, Inbal. Philips
roundup of the few Chopin works for piano with orch. aside from the two
familiar early concertos. Arrau does them solidly, effortlessly; but the two side 1
items are pretty heavy stuff, on the edge of being overblown-though
Schumann didn't think so at the time and hailed Chopin as a genius. True! And
so was S. The "Spianato" on side 2 is more familiar as well as more easily
digestible. The usual superb Philips recording.
A
6500 422, stereo, $7.95.
Bach: Mass in B Minor. Palmer, Watts,
Tear, Rippon; Amor Artis Chorale,
Engl. Chamber Orch., Somary. Vanguard VSD 71190/91/92 (3 discs),
stereo, $20.94.
The Four Antiphonal Organs of the
Cathedral at Freiburg. Bach: Four
Great Toccatas and Fugues. E. Power
Biggs. Columbia
raphonic, $6.98.
MQ
32933, SQ quad-
The Mass is more profound, more contemplative, more dramatic, than this professional -type big-time performance with its loud pro -style chorus, unblended, a too -prominent vocal quartet, a restless, bouncy quality to the faster
movements and not enough thought in the slow ones. The low soloists are
best-Helen Watts and Michael Rippon. It's all very brassy and somehow harsh
in sound, unperceiving. Somary is a lot better in Handel.
Biggs' effervexcent organ escapades -are always fun-but why does Columbia pick such unlikely acoustics for proving SQ "discreteness," complete
with diagrams? Four organs from one (electric) keyboard, panpotted into a
square, but the huge reverb allows only a vague directionality though the
sound is magnificently "surround"-and how. Sturdy Biggs Bach, quite intelligible in spite of the big mix.
Highlights from Handel's Judas Maccabaeus. Harper, Watts, Young, Shirley -Quirk, Amor Artis Chorale,
Wandsworth Sch. Boys Choir, Engl.
Chamber Orch., Somary. Vanguard
VSQ 30029, SQ quadraphonic, $7.98.
Johannes Somary's numerous Handel recordings-both complete and in excerpt format as here-are fast, efficient, modern, and very pro, adequately
"authentic" too; but musically find them on the hard, dogmatic side,
minus much feeling for rhythmic and dramatic balance. Top -rank solos-his
women are best (Harper, Watts); basso Shirley -Quirk rumbles like an earthquake. A very pro. chorus, loud, accurate, energetic, wobbly, and unblended. Yes-the old sanctimoniously sincere Handel of the mammoth
performance is gone. I sometimes miss it.
Stravinsky: Les noces (two early versions); Le Chant du Rossignol: Sym-
33201, stereo, $6.98.
Curious! Definitely for female voices and four pianos, a la "Sacre," Les noces
went through two discarded versions, 1917 with orch.; 1919, incomplete,
with percussion, two cimbaloms, harmonium, and player piano! Here are
both. Robert Craft's didactic touch doesn't give much life, though everybody works hard and well. And did they get the player piano working? He
doesn't say. I'd like to know. Wouldn't you? Unimaginative.
A Tribute to David Oistrakh, 19081974. Columbia MH 33328, 2 discs,
mono, $13.96.
If you are an Oistrakh fan, here are his U.S. recordings 1955-56, in excellent
mono fi, boiled down to two LPs from the original 3 discs. Mendelssohn,
Mozart, Vivaldi, Shostakovitch; at Phila. and New York.
Bolero; La Valse; Rapsodie
espagnole. Boston Symphony, Ozawa.
Deutsche Grammophon 2530 475,
stereo, $7.98.
The Ravel Centenary-and already he is so far away. Younger performers
miss the point, that steely, taut elegance of the earliest neo-classic. Ozawa,
in Boston, at least gets all of the drive and tension though tempi are hurried
and details not sharp. The big Boston liveness is superb for huge brass and
drums in this hair-raising Bolero; La Valse is fast and rightly maniac-the
waltz gone controlled -insane. Rapsodie espagnole (D -G mispells it on the
cover!) is split between sides, which spoils its mood.
Rogé is very much the younger neo -Romantic, even to long hair. His Ravel is
heartfelt, expert, but cast in a dreamy, untaut style that will astonish those
who thought they knew Ravel pretty well. Very slow, full of great pauses,
meditations, relieved only in the furiously fast movements-which Roge
does with easy ability. Fine if you have no preconceptions-but try Giese king's Ravel (Angel mono) for another generation's thinking.
phonies for Wind Instruments.
Orpheus Ch. Ens., Gregg Smith Singers, Col. Symph., Craft. Columbia M
Ravel:
Piano Music of Ravel, Vol. 1. Pascal de
Rogé. London CS 6873 stereo $6.98.
(Valses nobles et sentimentales, Tombeau de Couperin, Sonatine.)
I
AUDIO AUGUST,
80
www.americanradiohistory.com
1975
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Bob Cato
Al De Marino
V.P., A&R, A&M Records
V.P., Production, Capitol Records
V.P., Music Department, CMA
Tom Draper
Dir., R&B, RCA Records
Kenny Gamble
Pres. & Producer, Phila. Int. Rec. Co.
V.P., Marketing, Atlantic Records
Kip Cohen
Al Coury
David Glew
Emil LaViola
Dir., Artist Relations, Atlantic Records
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big fat trout lure for the taking, and
every so often somebody in the West
makes a grab and licenses the Czech
material. I can think of three or four
labels, including one of the major
"low price" lines, created especially
for Supraphon. Somehow, none of
them seem to have survived long.
Somehow, the sonic quality has always been a wee bit doubtful, and
who was to say whether the fault was
Supraphon's or the importers?
To change my analogy, think maybe Vanguard has now cracked this
I
particular nut. Vanguard's quality
control (their phrase) has always been
mi9ht
excellent and accounts for the superior sound on this company's reissues
over recent years. The sound was
there from the beginning. Maybe
Supraphon has updated? In any case,
these are flawless recordings, up to
anybody's high standards and up to
Vanguard's own. You won't find any
better surfaces, not even from Philips, either. A happy beginning, I'd say.
The Czechs understandably go in
for Czech/Bohemian music and, for
rather clear reasons, a bit of Russian
too. It is their strong point, this repertory, and nothing to be ashamed
of, politics or no. In listening here, my
be
only reservation, not a strong one, is
to note that (predictably) there is a
lower tension in this playing that we
in the West, especially in America,
somehow expect in our own performances. The Violin Concerto
benefits-you can push Dvorak just so
much and no more, anyhow. Shostakovitch in particular benefits a great
deal. The Fifth is traditionally played
over here with a certain beetle
browed fervor and sardonic intensity, which to my mind merely brings
out its fatuous side. Shostakovitch is
that way-too fulsomely seriousminded, which too easily turns into,
so to speak, serious-windedness. I
found the relaxed Czech performance very attractive. It takes the wind
out of Mr. S. but leaves the substance. Of which there is, really, quite
a lot!
George Flynn: Wound. John Cage:
Winter Music (version for 4 pianos).
George Flynn, pf. Finnadar QD 9006
(Atlantic), CD -4 quadraphonic, $6.98.
Well, here we go, and in quadraphonic too. Whammo! The various
schools of contemporary music, you
see, are just as rigidly stylized as
"classical" music has ever been, and
as pop music is too; this is the crash may wax
bang school of piano, if
descriptive. don't mean it is unimportant. I'm just saying that it is definitely, unswervingly crash -bang.
Also somewhat aleatoric, which
means, by chance, on purpose. The
Cage piece was a pioneer effort of this
sort back in 1960. George Flynn's own
work stems from Vietnam horrors as
of c.1968 and that is just the way it
sounds, all raw and bloody. I can practically hear the bullets tearing flesh
and the bombs and the shrieks of the
dying. Brrrr-stay away: war.
It seems anticlimactic to speak of
CD -4 is such a context, but in an ambient sort of fashion it does add to the
impact of Wound though the sound is
as of a single piano. In Winter Music
the CD -4 is more pointed. This curious collection of pianistic options on
paper-you take your choice, within
specified limits, as you play-is done
four times (all on the same piano, I
suppose) and each of these appears in
one channel, all at once. To be consistently aleatoric, Mr. Flynn did not
listen to the other channels via
phones as he laid down each performance The conjunctions of the
four, then, are completely chance, or
almost anyhow. Needless to say, they
are all different. Different choices.
So far so good. But this concept is a
lot easier to understand than to listen
to. No beat, no perceptible rhythm,
just very slow, casual dissonant
chords, produced every once in a
I
I
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AUDIO AUGUST,
1975
while on impulse, with great stretches of time in between. A rigorously
restricted format, even if important in
its implications. But who listens to implications?
Variationen über einen Walzer von
Diabelli (Variations on a Waltz by Diabelli). Jörg Demus, hammerflugel.
Archive 2708 025, 2 discs, stereo,
$15.96.
it won't sell (and at such a
So what! I can only tell you
that this is one of the most exciting
and dramatic piano recordings in the
history of the art and it really flipped
me. Not only the music, most of
which for a quarter century I have
wondered about in vain. But the inSo
price!).
struments, the "hammer grands"-no
less than three early 19th -century
grand pianos, with "wings," that is,
the raised -up tops, beautifully restored to like -new usefulness. And on
top of this, performance by Jorg
Demus that is no less than stunning.
Demus (remember him 'way back as
half of the two -piano Demus/BaduraSkoda team?) is one of the top keyboard exponents of the Viennese
school and, uniquely, a fine artist who
has given himself to performing the
older Viennese music on the instruments for which it was written. An unbeatable combination.
In 1821 Diabelli, a music publisher
and sometime musician himself,
launched a sort of piano competition
by inviting some 50 prominent
Austrian composers, including many
from what are now Czechoslovakia
and Hungary, to each write a variation on a little waltz of Diabelli's own,
the whole to be published in a grand
collection. Beethoven, in his late curmudgeon period, at first refused, then
testily came up with a gigantic work,
no less than 33 variations in late Beethoven monumental style, his last
big piano piece. It had to be published separately, of course. In recent
times most important pianists have
tackled the Diabelli Variations, and
eight recordings are now listed in
Schwann.
But what of the dozens by other
composers, including a variation from
such as Schubert, the boy Franz Liszt,
Czerny, Hummel, W.A. Mozart II
(Mozart's youngest son), and a host of
unknowns as of today? Not an audible
peep. The usual 19th -century leader worship has prevailed; (a) Diabelli's
Waltz is a nothing -Waltz (ah, but how
cleverly shaped for variations, as
Beethoven saw!) and (b) the other
composers were nothing -composers.
Well, here is the Beethoven, on one
disc, two sides complete. And here
AUDIO AUGUST,
1975
The Schwann Record Catalog
Did You Know That???
Did you know Mozart's Serenade No. 12, K. 388 is the same as his String
Quintet, K. 406? That Mozart's Concerto No. 2 in D for Flute is the same as
his Concerto in C for Oboe? That Bach's Concerto No. 3 in c minor for 2
harpsichords, S. 1062 is an alternate version by him of the famous Concerto
in d minor for 2 Violins? Bach's Concerto No. 1 in a minor for Violin, S. 1041
is the same as his Concerto No. 7 in g minor for Harpsicord, S. 1058? That
his Missa 1773 is the Kyrie and Gloria from the b minor Mass?
Did you know that both Rossini and Paisiello wrote an opera "Barber of
Seville?" Both Leoncavallo and Puccini wrote a "Boheme?" Both Gluck and
Monteverdi wrote an "Orpheo?" Music to "Romeo & Juliet" was written by
Berlioz, Gounod, Prokofiev, Tchaikovsky? Music to "Pelleas et Melisande"
was written by Debussy, Faure, Schoenberg and Sibelius? That some of the
most famous `Spanish' pieces were written by a Russian composer (Capriccio
espagnole) and a French composer (Rhapsodie espagnole, Bolero, Iberia)?
That Ravel wrote "Sheherazade" and Rimsky-Korsakov "Scheherazade?"
Did you know that there are records by 6 members of the Bach family?
111 of Bach's 215 surviving cantatas are recorded? That there are
records by both Mozart and his father? There are two composers named
Brown, 3 Jones, 6 Smiths? That "Haydn's Toy Symphony" actually is movements 3, 4, 7 of Leopold Mozart's "Cassatio?" That there are records of
music by King Frederick II of Prussia; Wilhelmina, Margräfin von Bayreuth,
Louis XIII, Benjamin Franklin? That composer/musician Pablo Casals lived
to be 97, Julius Reubke died at 24?
That
-
What else can you find? Be sure to get a Schwann Record Catalog each
month
an indispensable reference work which should be in every home.
Available at record dealers everywhere.
For a sample copy, sent postpaid directly
to your home (but please try your
record shop first) send
$1.60 check.
Schwann Record & Tape Guide
137 Newbury Street, Boston, Mass. 02116
85
www.americanradiohistory.com
are you
missing
the surprise
in Haydn's
Surprise
Symphony?
It was probably intentionally sacrificed by
the record or tape manufacturer (for reasons
we explain in our literature).
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are most of the others, more than 30
of them, on the second disc!
Beethoven, of course, towers high
and waxes difficult as we already
know from standard -piano versions.
But let me tell you, all things considered, the other composers including unknowns from Assmeyer(!) to
Worzischek are extraordinarily good.
There is not one of the short pieces
which is in any way stupid, banal or
trite; many are really beautifully contrived. If any similar group of our own
contemporaries could turn out such a
high-level and well -styled collection
as this, we could be said to have a
developed culture. Beethoven, we are
now given to understand, stood high
on the shoulders of other men. Without them, he would have been, let's
recorder.
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minor Ives.
straight through these consecutive little pieces-the Diabelli
Waltz holds them together admirably
for the ear, and Carl Czerny's brilliant coda carries the whole to a
cheering, scintillating finish, and you
don't need to know which is Schubert or Liszt, which Assmeyer. It all
say, a
Play
flows.
By far the most notable of the three
pianos, as recorded, is the Gröber,
1815-25, out of Innsbruck, built in an
earlier type of configuration. It is used
for most of the non -Beethoven variations, alternating easily with the
similar British Broadwood of 1802. On
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disc, this Gröber is extraordinary-such brilliance of color and timbre, not cool stainless steel as our
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bronze, wiry like
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thunderous
Hungarian zither with keyboard attached. It sounds out as the loudest of
the three, but this is undoubtedly a
recording phenomenon. The Broad wood is a milder version of the same.
Beethoven's music is played on a
tougher, later, harder, Conrad Graf
piano of 1839, like the last piano
Beethoven owned. It seems less
loud-but again this is surely because
of its much heavier percussive
sounds-violent transients difficult to
record.
Did Beethoven himself pound out
these hard -edged metallic forte jabs?
Without a doubt! He was well known
for breaking strings.
Correction
May's Classical Reviews of Michael Murray's Bach and Widor
recordings listed an inoperative
address. Organ recording enthusiasts can now order these
discs from:
Revdv
155 Michael Drive
Sunset. NY 11791
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www.americanradiohistory.com
J
86
AUDIO AUGUST,
1975
Jazz & Blues
Before we
started making
speakers,
we made
something else.
A commitment.
Hampton
Hawes
at Montreux,
1973
Three
LP Records
Playin' in the Yard: Hampton Hawes
Musicians: Hawes, electric and acoustic pianos; Bob Cranshaw, electric
bass; Kenny Clarke, drums.
Songs: Playin' in the Yard, Double
Trouble, Pink Peaches, De De, Stella
by Starlight.
Prestige P-10077, stereo, $6.95.
Hampton Hawes, master contemporary keyboard artist, makes up for
lost recording time in this series of
three Montreux Jazz Festival releases
from Prestige Records. Hawes slipped from view in this country in the
mid -Sixties, leaving recordings and
memories of his vibrant bop style. Recently he returned on Blues For Walls,
his first Prestige release. At that time
he showed broadened capability at
the keyboard and as a composer.
On these live recordings Prestige
has captured the added dimension of
this marvelous musician in company
with his peers. Listeners will find time
flying as they enjoy Hawes' excursions on acoustic as well as electric
piano.
His tasteful and sprightly use of the
electric piano is gratification a -plenty
for this keyboard-o-phile. He dances
AUDIO
fancifully over the keys on the medium -tempo blues Double Trouble,
then Cranshaw continues, frolicking
on his Fender bass before the trio
goes into the rock section of the number. This lasts for several choruses before Hawes switches to acoustic
piano. Bass and drums drop out, and
he revs up his motors for an extended solo flight. He's like a lark as he
zips in and out of tempi with never
the slightest hint of uncertainty. He
highlights part of this cadenza painting a blues rainbow with his right
hand while underlining it with a
groovy walking -bass line in the left.
Bob Cranshaw deserves credit for
his keen ear and excellent time. His
notes throb with that extra duration
exercised only by top bassists. He
does a fine job of holding things together in Pink Peaches. The tune begs
for a funky -street beat, which Clarke
is unable to supply, apparently because he's unfamiliar with jazz-rock
and tends to play a rather cluttered
style here. And, though he makes a
noble effort, his time wavers. But with
Cranshaw present, Clarke finds the
right way back to the time.
Playin' in the Yard, the title tune
and longest cut on the date, is done
almost as two -beat swing.
say almost, because Clarke vacillates be -
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"A best in its class..."
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Stereo Review-April, 1974/
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-
U
I
AUGUST, 1975
87
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tween the two -beat and the more
funky rock beat which Jack De John ette played behind the tune on Rollins' Next Album. Nevertheless, the
tune comes off very well. Cranshaw
cops some solo time ably backed by
Hawes' clever and effective understatements. This is an excellent tribute to tenor giant -composer Sonny
Rollins.
My favorite cut
is
easy mellow ballad,
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Blues
Suisse: Dexter Gordon
phone, Hampton Hawes, electric and
acoustic pianos; Bob Cranshaw, electric bass, Kenny Clarke, drums.
Songs: Gingerbread Boy, Some Other
o
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Stitt's work (Tune Up, and Constellation, on Cobblestone). Then
ran
across an album of Gene's called Big
Band Jug. Need say more? And then
when looked down the list of tunes
and personnel on this record
guessed he was into some heavy
blowing.
Sure enough, was right. The quartet opens with Yardbird Suite. After
mystically working through the head,
in a Night in Tunisia vein, Ammons
takes off for a whole bunch of swinging choruses. New Sonny's Blues by
Sonny Stitt gives us the delightful
opportunity to catch the rhythm section doing the blues-featuring a
Hawes solo after one by Jug.
Ellington's beautiful Sophisticated
Lady brings out the soft side of AmI
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P
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Songs: Yardbird Suite, Since 1 Fell For
You, New Sonny's Blues, Sophisticated Lady, Treu Bleu
Prestige. P-10078, stereo, $6.95.
Surprise! Well, to me, anyhow. The
late Gene "Jug" Ammons shows that
on this recording he had turned away
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,
Spring, Secret Love, Blues a la Suisse.
Prestige P-10079, stereo, $6.95.
Dexter Gordon's last release, Generation, is a tough act to follow, especially when you know hands down
that it was his best album to date, featuring an explosive rhythm section
and more than noteworthy solos by
Freddie Hubbard and Dexter. It
would be even tougher to follow if
anyone else had to do it. But since
Dexter plays better all the time, if better than great is possible, and since
live recordings are more natural than
studio dates, Blues a la Suisse is way
up there near Generation.
This is a quartet date featuring Gordon on tunes he has not previously
recorded. Gingerbread Boy, by
another tenor giant, Jimmy Heath,
gets a thorough going-over by Dexter. Played somewhat slower than
Miles Davis played it on his record the
tune looses none of its punch.
As with the rest of the album Dexter monopolizes the solo space on
Secret Love, giving what's left to
Hampton Hawes. I confess, I've been
spoiled py the way James Moody did
Secret Love on his Never Again album. The head on Moody's version
sounds tighter because the rhythm
section is tighter, and Mickey Tucker
vamps the opening rhythmically in a
most 'compelling fashion. Nevertheless, Dexter compensates with a superb solo flight of his own.
Sound:
B
Performance:
BT
Ammons and Friends at Montreux:
Gene Ammons
Musicians: Ammons and Dexter Gordon, tenor saxophone; Cannonball
Adderly, alto saxophone; Nat Adder -
I
I
I
I
mons. His solo is sweet and relaxed,
and Hawes' cute and subtle runs make
ideal backing.
Dexter Gordon and the Adderly
brothers arrive in time for the merriment of the finale on Treu Bleu, an
Ammons up -tempo swinging original. Nat Adderley's creative use of staccato notes in a syncopated array is the
most effective solo of the lot. Toward the end of the tune the four
horns play leap frog, swapping four bar phrases all around. After an effervescent statement by the four in unison, it's back to the head. The ensemble work is slightly sloppy, but
who cares after the walloping these
titans give the tune?
It's anti -climatic to say there is
something that mars this otherwiseexcellent performance. It's Kenny
Clarke's drum work. He tries too
often to do too much. And his kicks,
instead of propelling the group, get in
the way. If you let that one deficiency
keep you from buying this record you
will just miss one of Gene Ammons'
best performances on record.
Sound:
B
Performance:
As to the technical quality of these
three recordings, you can get a fair
sample by listening to Hawes playing
AUDIO AUGUST,
88
Check No. 23 on Reader Service Card
www.americanradiohistory.com
B
1975
the head of Playin' in the Yard. Behind him you can hear the snares vibrating clearly, and throughout the
rest of the tune the cymbals come
through cleanly, showing treble
sound comparable to most studio recordings. Cranshaw's bass is also vibrant and undistorted, highlighting
the good, firm bass reproduction.
These three Montreux albums contain hours of pleasurable listening. If
your ears can stand a bit of drum
noise, or if you can do a little on -the spot drum editing, you'll find the
music here is top notch. To those responsible for choosing the musicians
for the Festival, I say a more appropriate drummer could have been
found.
If you must choose between these
discs, choose Blues a la Suisse.
Eric Henry
Preclusion: Patrice Rushen
Musicians: Rushen, electric and
acoustic pianos, clavinet, ARP synthesizer; George Bohannon, trom-
bone; Oscar Brashear, trumpet,
flugelhorn; Hadley Caliman, flute,
alto flute, soprano sax; Joe Henderson, tenor sax; Ndugu, drums; Tony
Dumas, electric bass, "blitz" bass;
Kenneth Nash, percussion.
Songs: Shortie's Portion, 7/73. HawRight Now, Traverse, Puttered Bop corn.
Prestige 10089, stereo, $6.95.
Patrice Rushen is all of 20 years old.
Wow! Can you believe it? An album
chock full of her own compositions
and arrangements on which she
shows off her keyboard talents. You
might think that for someone to
arrange her own recording session at
such a young age she must be the
child of movie stars or record producers or some such. Not here! No
way! There's no nepotism or anything else involved here, save the
merits of a young talent hard at work.
Patrice is excited about her first record, and rightfully so. It represents
her-Vie dues she's paid, the culmination of her previous musical experiences with trombonist Melba Liston,
singer Abbey Lincoln, various soul
groups and studio work and, of
course, her producer and teacher
Reggie Andrews.
Shortie's Portion makes a swinging
helping for any avid pair of ears. Miss
Rushen is on acoustic piano here for
two solo outings, separated by a couple of horn solos. Her solos show the
influence of McCoy Tyner, among
others. More than that, they herald
the arrival of a developing keyboard
giant sprouting much more than
musical cliches and memorized riffs
and licks.
AUDIO
AUGUST, 1975
89
Why any cartridge
(even ours)
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grams, a Shibata stylus is easier on
your records than an elliptical stylus
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All Audio-Technica top -of -the line cartridges have genuine Shibata
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As a premium stylus, elliptical designs have only one real advantage
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Which is why we still offer them.
But when it comes to performance, a Shibata stylus is far, far
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the penalty of requiring extremely
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In fact, even tracking at up to 2
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audio technicao
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The two horn solos are by
trumpeter Oscar Brashear and tenor
saxophonist Joe Henderson, who
sounds magnificent here which is not
unusual when he and his irre placable, unrelacquered, mellow old
tenor sax get together. It is unfortunate that Henderson's own re-
on the already overly -exploited ear.
Henderson is heard to great advantage on albums by other artists including Flora Purim's Butterfly Dreams
(Milestone M 9052) and Ron Carter's
All Blues (CTI 6037). When Henderson gets together to play good music,
what comes out is one of the most
cent releases, The Elements
identifiable and influential reed
(Milestone MSP-9040) and Black is the
Color (Milestone M-90530 are not
commensurate with the talent that the
man has to offer. This is simply due to
the musical variety being constricted
to no more than a hair's breadth,
hence posing overbearing limitations
voices in music today. This is certainly the case here.
Miss Rushen's compositions are in-
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terestingly constructed. There aren't
any hodge-podge, hackneyed themes
or lines to be trampled over just once
more. 7/73 is a beautiful bossa -like
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Polk Audio
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a
ballad which Patrice sprinkles with
spice and everything nice on electric
piano. If there are any influences on
her compositions (what am I saying?
of course there are; everyone has
some),
detect some Thad Jones in
the phrasing and rhythmic structure.
The tune hints at Thad's It Only
Happens Every Time from Thad Jones
and Mel Lewis' Consummation LP
(Blue Note BST 84346).
Traverse really is an appropriate
title for this tune. Much musical
ground is covered. The beginning
brings to mind the sounds of a summer evening with little more than the
breeze of a soft wind and a Jiminy
Cricket scampering lightly over the
keys of the acoustic piano. Then,
Patrice swings lightly with bass and
drums (no horns). And, suddenly,
magically, we are whisked away to a
super -samba wonderland.
Today, as music expands in all directions, there is a growing expectation of and necessity for the new
keyboard artists to be familiar with the
I
whole array of keyboards. On
Puttered Bopcorn, a super funky tone
and not a redone bopper, as the play
on words suggests, Miss Rushen performs on Arp Synthesizer. Bassist Tony
Dumas helps groove this tune. By the
way, what is a "blitz" bass?
In order for some folks to be
swayed to purchase an album, the
music has to fit some label or category. Is it all swing? Or Latin? Rock,
Bop, or what? Preclusion is all of these
and more. It's not hung up in any one
bag; it's all good music. And, if you
have to have a label for it, it's all
Patrice Rushen! Here's where the
one-time diamond-in -the -rough has
made the transformation into a still being -polished, but glowing gem.
Nothing adds more to an album of
good sounds than sound reproduction. Justice has been done in
mixing and pressing this LP, as much
as can ordinarily be expected by
American standards. highly recommend Preclusion.
Eric Henry
I
Performance: A -
Sound: B+
Greatest Jazz Band: Jimmie
Lunceford and his Orchestra. Olympic Gold Medal 7123, mono, $4.98.
The title of this album stakes out a
brash and extravagant claim certain to
be challenged by admirers of Basie,
Ellington, Goodman, and Fletcher
Henderson, at the very least. While
certainly not the greatest of all jazz
groups, Lunceford's crew was in the
front rank, dominating, along with the
four mentioned above, the big band
The
At $119 each, we can hardly believe it ourselves
4900 Wetheredsville Road, Baltimore, Maryland 21207
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scene in the Thirties.
Check No. 30 on Reader Service Card
90
AUDIO AUGUST,
1975
In a way, Lunceford's and Basie's
bands were complementary, each
making its forceful impact by different means. Where Basie's men drove
into blues and stomps with roaring
enthusiasm, their simple riff style propelling the mounting orchestral tension, Lunceford relied on the opulence and detail of studied orchestrations and more precise execution, approaching, closer than any other
band, the standard set by Benny
Goodman which brought this kindof
ensemble playing closest to perfection.
The Lunceford band was one of the
slickest show bands of all time. Its
trumpet men dazzled audiences with
gimmicks such as throwing their
horns in the air and catching them
with the accuracy and timing of professional drum majors. The trombone section would swivel right and
left while playing swinging tunes-a
trick that Glenn Miller copied and
which contributed to his band's
popularity.
But what the stiffer and more
mechanical Miller band could not
copy was the innate ensemble quality
that made Lunceford's the most relaxed of orchestras. The lazy, caressing beat of Morning After is as fine a
tribute to the Lunceford discipline as
the precision and swing on the up tempo Battleaxe. Moonlight and
Music and the Sy Oliver arrangement
of I'm Walking Through Heaven With
You, though it has a Dan Grissom
vocal, really showcase the opulent
sound of the Lunceford sax section.
Led by altoist Willie Smith, the cohesion and instinctive understanding of
the five -man reed team is readily
apparent. Their phrasing and blending are so complete that the listener is
all but convinced he's hearing a single
instrument. The Lunceford sax section achieved the most delicate pianissimo effects, yet it could swing the
whole band with tones as forceful as
the band's vigorous brass. Annie
Laurie, a Lunceford standard, is a fine
swinger which spotlights the brass
section in a vivid, sharply -disciplined
performance. Trummy Young's bold,
open trombone work is a consistent
joy, along with Paul Webster's piercing, high -register trumpet solos.
The gifted arranger -trumpeter Sy
Oliver, who was the most important
shaper of the band's sound, had gone
over to Tommy Dorsey by the time
these recordings were made. With TD
he was to achieve greater fame and
make more money, but the Oliver
influence remains in each of these
selections. All are played in the relaxed, crisply -phrased Oliver manner. Even the highly commercial ar-
AUDIO
AUGUST, 1975
91
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rangements that back singer Grissom
reflect the brilliance and subtlety of
Oliver's scoring. Needless to say, this
Lunceford collection is highly recommended.
All of the tracks on this Olympic LP
were taken from the Long -Worth Co.
radio station library. They were recorded in 1942-43. The pressings of
those transcriptions (16 rpm) had
respectable sonic quality for the day.
John Lissner
Sound: B+
Performance: A+
GOOD
titillating sounds,
Weber
classical and jazz idioms. It's not fusion in the sense of the familiar jazzrock fusions we know so well. Instead each selection maintains its own
musical identity. There's no watered
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Musicians: Weber,
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bass,
cello, ocar-
ina; Rainer Bruninghaus, piano, synthesizer; Peter Giger, percussion; Ralf
Hubner, drums; Ack van Rooyen,
flugelhorn.
Songs: More Colours, The Colours of
Chloe, An Evening With Vincent Van
Ritz, No Motion Picture.
ECM 1042 ST, stereo, $6.98.
Nothing less than great music from
beginning to end! This music far surpasses what words can say about it.
Weber has created an album full of
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employing both
The Colours of Chloe: Eberhard
on Reader Service Card
Markham, Ontario
(416) 495-0880
own thing, yet somehow
they complement each other perfectly. Weber's orchestrations for the
cello section of the Sudfunk Symphony Orchestra lay an elastic foundation which maintains the discipline
of classical music even while allowing
the jazz section to function freely.
Close your eyes and savor the
delectable piano solo on Colors of
Chloe. Bruninghaus brings us out of a
forest of strings into a cool summer
waterfall. Sparkling and refreshing
notes form a melodic continuum over
the ridges of the rhythm section. You
like flugelhorns? Well, Ack Van Roo yen plays the plating right off his horn
on the free 'n up Evening with Vincent Van Ritz.
What else the album has going for it
would take up more space to describe than is available. There's good
music here and there's lots of it.
Everyone's ideas gel together splendidly without being hindered by the
muck of technique that often results
when young masters get together.
Weber plays a five -stringed bass. If we
couldn't figure th, at out from his octave jumps on Chloe, the picture on
the back cover would tell us.
Each is its
Colours of Chloe
is
on ECM-the
Rolls Royce of jazz labels. Only superior music is allowed to grace these letters of distinction, so conventional
sugary string and geared -up synthesizers are 4bsent. Rather, Weber
draws uncanny voicelike textures
from these usually over -exploited instruments. What we've been conditioned to expect from synthesizers
and strings, and what he's produced
are at opposite ends of the spectrum.
The sound of Colours of Chloe is
not the sound of Europeans imitating
jazz from America, as happened after
bop, in the Fifties and Sixties in Europe. Weber is representative of many
younger European musicians, developing music that is new, modern, and
distinctly their own. Eberhard Weber
isn't Chick Corea, but his music is just
as valid. His reputation will grow
among afficionados of good music,
and then ... well ...
This is one of the year's better jazz
releases, whether it sells or not.
Eric Henry
Sound:
92
A
Performance: A
AUDIO AUGUST,
1975
i
Tape & Turntable
Bert Whyte
Appalachian Spring. Aaron Copland,
composer, conducting the Columbia
Chamber Orchestra. Columbia MQ
32736, SQ disc, $6.98.
If you are familiar with the music of
the ballet suite, scored for full orchestra, you will be fascinated with
this (the original) chamber orchestra
version which utilizes only 13 instruments. Aaron Copland tells us that the
scoring and the size of the orchestra
were dictated by the size of the small
concert hall in the Library of Congress, where Martha Graham was to
dance the premiere performance.
Needless to say, this is a much more
intimate sounding version than the
full orchestral suite. When you're listening to it, inevitably your mind supplies the missing brass and percussion and the other parts with which
most listeners will be familiar. This is
very clean, open sound, with beautiful strings and woodwinds in a quadraphonic recording that furnishes
lovely warm ambience, and proves
that four -channel sound can be successfully used in small -scaled productions. Appalachian Spring is, of
course, a masterpiece and always a
delight to hear, whatever the format.
Peter and the Wolf: Prokofiev. Young
Person's Guide to the Orchestra: Britten. Will Geer, narrator. J. Somary w.
English Chamber Orch. Vanguard
VSQ 30033, SQ quadraphonic disc,
$7.98.
A glance at the latest Schwann cata-
log reveals that there are 15 recordings of Peter and the Wolf, and 12 versions of the Young Person's Guide,
with narrators as diverse as Capt. Kangaroo, Peter Ustinov, Boris Karloff,
and Mia Farrow, to name just a few.
Obviously, this new Vanguard recording is up against some stiff competition, but it has some very potent
factors in its favor. For one thing, it is
the only quadraphonic version currently available. This in itself might
not influence some people, but believe me, this is quadraphonic sound
of rare excellence, and a most persuasive reason for using this medium.
recording in stereo, and then
play it through a reasonably sophisticated SQ decoder. The enhancement
of the acoustic perspective is dramatic, and the sense of involvement in
the recording environment is so real,
that the stereo sound seems confined
and almost one-dimensional by comparison. There is little quadraphonic
"trickery" employed here
no
.
wildly -swinging pan -pots or channel
switching. The object here was to
achieve very natural sound, exemplified by a feeling of air around the instruments; a smooth, spacious projection of all the orchestral elements,
without "spotlighting" for exaggerated effect, nor the stridency which
mars far too many recordings these
Play this
days.
The sound is ultra -clean, with extended high frequency response in
the silky sheen of upper register
strings. The very exposed and open
scoring of Peter and the Wolf calls for
precise internal balances, and in this
recording they are splendidly realized. never heard any instrument or
I
group of instruments cover or
"swamp" one another.
In this type of recording the narration is usually recorded separately
from the music, and then spliced in at
the appropriate places in the score.
This was done here nigh to perfection, with most discreet and judicious
use of plate -type reverb for continuity between voice and orchestra.
Will Geer, who does the narration,
is a fine character actor currently appearing as the gruff old grandpa in
The Waltons television show. Rather
amusingly, in the Young Person's
Guide, he does the narration in a
pleasant well -modulated voice, with
beautiful diction, but in Peter and the
Wolf slips into his "mountain twang"
and at times the "compone" gets a
little thick. No doubt devotees of The
Waltons will feel very comfortable
with his performance.
All in all, this is a superb recording
with some really rich sonorities. Listen to the Procession in the finale of
Peter and the Wolf for some great
blaring brass sounds and the clean,
solid impact of low frequency percussion.
AUGUST, 1975
93
,
)
the audio
amateur
4
The brain boggles at what old
Johann could have done with
his own console, preamp,
8 -in -2 out mixer, octave equalizer, electrostatic speakers, or
24 inch woofer.
Come boggle with us.
emAudio
Box 30A
Swarthmore,
Pa.
19081
= LtsU
Craig Stark of STEREO REVIEW says:
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Theater Music
J
Donald M. Spoto
Sunset Boulevard: The Classic Film
Scores of Franz Waxman. National
Philharmonic Orch. Chas. Gerhardt.
RCA ARD1
0708,
CD -4 Quadradisc,
$6.98.
the 1930s, Hollywood had come
long way since the days of the
mighty Wurlitzer, the large pit orchestra and the matinee music which
accompanied films. This early music
was performed more for pragmatic
than esthetic reasons: the whirr of
projectors, the banging of movable
chairs, and the noise of undisciplined
patrons had to be masked.
With the advent of sound film,
major studios realized the importance of a good musical score. Dramatic value (ór more accurately, melodramatic value) was added, and serious composers were commissioned
for major films: Arthur Honegger,
Dmitri Shostakovich, Sergei Prokofiev, Virgil Thomson. Some composers, however, became famous for
their film scores alone, and among
RCA's numerous new releases, none
is more significant than this one of
Franz Waxman's work.
Two-time Oscar winner (Sunset
Boulevard and A Place in the Sun,
both included in this recording), Waxman may well be, with Bernard Herrmann, the greatest of film composers. The moment of creation in The
Bride of Frankenstein (1935) owes
much of its emotional complexity to
Waxman's beautifully terrifying score
with its glorious bells and eerie understanding of the thin line of demarcation between the grotesque and the
gorgeous. Hitchcock's first American
film, Rebecca (1940), was enhanced by
his sensitive neo -Gothic music, and
By
a
94
The Philadelphia Story had Wax man's genius adding delicious counterpoint and bittersweet harmony.
His scores for Prince Valiant (1954),
Sunset Boulevard (1950), and Taras
Bulba (1962) are surely interesting,
and far better than the kind of monotonous lushness to which Max Steiner and Alfred Newman too frequently descended. But Waxman's greatest
scores are not represented in this album. They are Sayonara (1957) and
The Nun's Story (1959), the latter very
likely the finest film score ever composed. It is long out of print in its original Warner Brothers soundtrack version, with that lovely photo of Audrey Hepburn in white veil and wimple on the album cover. My own
much -played copy may be one of the
few copies around.
Franz Waxman has the kind of
imagination, sensitivity, understatement, and depth of feeling that make
him one of the great composers of
our time in a very special kind of
genre. He deserves better than this
disc, on which Charles Gerhardt and
the National Philharmonic (whomever they may be) perform loudly but
without great feeling. And the cloying rumbles in the bass may lead you
to think you've amp trouble. Not so;
it's just a badly cut quadradisc.
Performance: C
Sound: C
Judas Maccabeus (Highlights): Handel. English Chamber Orch., cond. by
Somary.
Singers: Harper, Young, Watts, Shirley -Quirk.
Vanguard VSD 71200, stereo, $6.98.
The musical genre oratorio originated in Rome about 1600, with perJ.
formances of religious cantatas at the
oratory of St. Philip Neri, whence the
name. The history of the English biblical oratorio can be dated to 1732, the
premier date of Handel's Esther.
Among that composer's other oratorios, few are as popular as Judas
Maccabeus, and this Vanguard recording of highlights is a splendid version indeed.
Conductor Johannes Somary,
whose precision and style we have enjoyed for many years in New York,
where he is music director at the
Church of Our Savior, leads an enthusiastic cast and the English Chamber Orchestra. Somary rightly emphasizes Handel's airy touches in this 1747
work. He keeps the Amor Artis Chorale and the Wandsworth School Boys'
Choir stoutly in front of baritone John
Shirley -Quirk in the finale Rejoice,
Oh Judah! but modulates them for
the soprano -alto duet with chorus,
Hail, Hail Judea, Happy Land! And
who could repress a smile at Sound an
alarm! The trumpets fairly open up
the celestial gates at music like this!
Heather Harper's soprano has a lilting, sustained quality in this recording that has not always been evident.
Wise Men, Flattering is delivered with
elegance and control-not easy, given
the phrasing Handel and his librettist
Thomas Morell indicated. Vanguard
and Somary demonstrate good taste
and a high degree of professional
musical ethic in this and related discs.
And the cutting has been done without warble, whoosh or scratch. The
18th century couldn't have had music
reproduction, but if it had, how
pleased Handel would have been with
this!
Performance: A
AUDIO
Sound: A
AUGUST, 1975
Classified
FOR SALE
FOR SALE
FOR SALE
AUDIO RESEARCH MAGNEPLANARS and Electronics,
ESS, Infinity, Ohm, Dahlquist, EPI, Audionics, Radford, Crown,
Citation, BGW, Transcriptor, Linn-Sondek, Keith Monks, ERA,
RECORDING TAPE CLOSEOUT: Dozen reels 2400',
$12.00. Dozen 1200', $8.00. 24 reels 900', $6.00. 24 600',
$5.00. Postpaid Guaranteed. Mitchell, Box 132A, Flushing,
N.Y. 11367.
Decca, Grace, Sony,
Spectrum
Connoisseur. SME, Supex,
Scanning Tuner, Epicure Amplifier, Marantz 500, DBX, ADC,
Nakamichi, B&O, Tandberg. Celestion, Marc Levinson, Stax,
Dayton -Wright, others. THE GRAMOPHONE LTD., 757 Asp
St., Norman, Okla. 73069.
405-364-9477.
CROWN 01200 & M2000 on demo in our showroom. The
cleanest amp ever made, driving RTR STUDIO MASTERS. Cyberacoustic Laboratory, 503 Haverford Ave., Narberth,
Pa.
19022. 215-667-3048.
NEWS MAGAZINE -Covering Commercial -Display Fireworks, Sources, Construction. Black Powder, Fuse. Literature. Firecrackers To Bombshells! Interesting
FIREWORKS
-25c
With Sample -$1.00
Catalog
12010-P, Lexington, Kentucky 40511.
ORTOFON
-
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Press,
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SUPEX CARTRIDGE OWNERS; our Micro-
Preamp outperforms any transformer. Free literature. Hunt-
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ELECTRONIC CROSSOVERS -ALL TYPES. Definitive
booklet describes applications; how to improve speaker systems; $5.00, credited to first purchase. Huntington Electronics, Box 2009, Huntington, Conn. 06484.
FLASH -WORLDS FIRST HIGH OUTPUT MOVING-COIL
CARTRIDGE WITH REPLACEABLE STYLUS is now in
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surpasses ALL other cartridges in clarity, separation, and ultra -low distortion. Has rock -solid bass definition, and the realism heard from solo or massed violins is incredible. $265.,
with choice of conical, elliptical, or Shibata-type stylus; cartridge with all three (interchangeable) styli purchased togeth-
$450. Sister models with similar qualities, $145. and
$215. At better dealers, or direct from exclusive U.S. distributor, AUDIOPHILE IMPORTS, 10 East Erie, Chicago, IL
60611.
er,
LOWEST DISCOUNT PRICES ANYWHERE on audio equipment. All major brands discounted. Write for quotes, K&L
Sound Services. 75 N. Beacon St., Watertown, Mass. 02172.
DIAMOND
NEEDLES and Stereo Cartridges at Discount
prices for Shure, Pickering, Stanton, Empire, Grado and ADC.
Send for free catalog. LYLE CARTRIDGES. Dept. A, P.O. Box
69 Kensington Station, Brooklyn, New York 11218.
ESS Preamp,
N.Y.
$275. John Igarashi, 144 Redfield, Syracuse,
13210.
MONEY SAVER! Write
1$18, Miami Beach, FL 33139.
THE
STEREO
SPECTRUM, Box
ARP SYNTHESIZERS!
$920. Odyssey $1230. String Ensemble $1385.
#2600 $2385. Dickstein Distributing, 1120 Quincy Avenue,
Scranton, Pennsylvania 18510.
Pro -Soloist
DON'T LET VOLTAGE TRANSIENTS ZAP YOUR HI-FI.
Solid State Equipment Protector. Plugs into outlet. Check or
money order $6.95. Kopp Sales & Service, 1650 William St.,
Buffalo 14206. Free brochure -send SASE.
QUOTES ON 60 POPULAR BRANDS. Specializing in "high
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Phase Linear, Phillips -much, much more. Sound Center,
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MACINTOSH just completely overhauled by factory! Pair
MC -60 power amps, C-20 stereo pre -amp, MR -55 AM -FM
Multiplex tuner. $500 + shipping. (614) 592-1789.
BUSINESS PROPOSITION extended to you Rock Barons
with surplus dough begging for work. Did you know that you
can increase your earnings by just making your music installation more acceptable and far less punishing. Then just pool
your moneys and come up to my OTW studio located in High -
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a slot coupled to -air -mass featuring the equivalent, down to fundamentals.
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emotionally fatiguing. No standing waves. No room feedback.
We'll build you a knockdown model. hand you over the patent drawings for a 'song'. Call for appointment: MERCKO,
WYandorte 2-1674.
bridge,
OPERA TAPES. Historical performances of past 40 years.
Unbelievable treasures and rarities. ALSO LP RECORDS. Free
catalog. Ed Rosen, 66-33 Saunders St., Rego Park, N.Y.
11374.
- 1/4W, 5% carbon film from 10
3.3 Megohm for 311c each. Fifty of one value for $1.25.
1N4148 diodes for 6c. Ceramic capacitors. Free samples/specifications. COMPONENTS CENTER -A, Box 134,
LOW NOISE RESISTORS
-
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CONNECTICUT: Yamaha, Celestion, IMF, Infinity, Braun,
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vex. Stellavox, Thoreau, ESS, Mark Levinson, Supex, BGW.
Will ship prepaid. AUDIOCOM, 177 Sound Beach Avenue, Old
Greenwich, Conn. 06870. (203) 637-3621.
WANT TO GO BI -AMP?
DeCoursey Electronic
Dividing Networks are available from
$89.10 (Monaural hi -amp) to $205 (Stereo tri -amp). Price
includes plug-in Butterworth filters; 6, 12, or 18 db. per octave at any desired cutoff frequency. Write for brochure. DeCoursey Engineering Laboratory, 11828 Jefferson Blvd., Culver City, California 90230.
TUNED ROCK P.A.'s. Customized high intensity touring/permanent installation sound systems, including narrow
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CASSETTE LABELS
Plain white cassette labels, Norelco cleaners, paper mailer
boxes hold Norelco type plastic box, famous brand cassettes.
Send for open reel and cassette discount catalog.
1-9 10-99 1001000 10M
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Norelco Cassette Cleaner
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At last! An open reel catalog, including titles, songs, etc. of 95
long play, 2-3 hour albums, by American Airlines or Ampex 4
track stereo tapes. Send $1.00 -and we will
also mail you a 140 -page Harrison stereo tape
you'll get both for $1.00 -and this
guide
-so
$1.00 is refundable on your first $10.00 purchase of open reel stereo tapes at our 30%
discount
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STEREO CO-OP. Now purchase stereo components directly
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Members include Advent, Bose, EPI, Pioneer, Sansui, Dual,
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D.C.
20006.
KLIPSCHORN-KLIPSCHORN-KLIPSCHORN Only the finest in Audio. Superior Sound Stereo Center, 2780 Erie Blvd.
E., Syracuse, N.Y. 13224.
ONE STOP for all your professional audio requirements. Bot-
tom line oriented. F.T.C. Brewer Company,
Pensacola, Florida 32505.
P.O.
Box
8057,
DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES
WAREHOUSE OF SARASOTA 6564 GATEWAY AVENUE,
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You can assemble your own high quality, multi -element stereo speakers in a few hours and save up to half the cost of
comparable speakers. Send for our tree 32 -page catalog of
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CANADIANS
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En
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AT TREMEN-
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CYBERACOUSTIC LABORATORY: only one of its kind!
Featuring Crown, IMF, AKG, UREI, RTR, DBX, Infinity. Rabco,
Decca, Mark Levinson, more. Crown warranty service. Featuring Crown tape recorders: Audiomodtronics by our engineers.
Barclay -503 Haverford Ave.. Narberth, Pa. 19072; 215667-3048.
MAXELL TAPES. AKG microphones. Stax headphones at
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STREET, STAMFORD, CONN. specializes in equipment for
the connoisseur. Ampzilla. Audio Research, ADC. Citation,
Crown, Dahlquist, Dyna, Epicure, Infinity, Philips, SAE, SME,
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Stax, TEAC, Technics, Thorens and many more. (203) 348-
J.B.L./Altec Pro.. Tascam, U.R.E.I., Eventide, Gately, Schoeps,
Beyer.
Crown, Community Light/Sound, Mom's Audio,
Sound Ltd. 11!/2 Old York Rd., Willow Grove, Pa.
(215) 659-9251.
3551 (Closed Mondays).
Rates: 35u per word per insertion for noncommercial advertisements; 60E per word for commercial advertisements. Frequency discounts as follows: 3 times, less 10"'0; 6 times, less 15" e; 12 times, less 20°%o. Closing date is the FIRST of the second month preceding the
date of issue. Payment must accompany all orders. Use the handy self-addressed, postage paid card at the back of this issue. When replying to Audio box number ads, send letters c/p Audio, 134 North 13th Street, Philadelphia, Pa. 19107. For more information about classified advertising, circle Reader Service Card #135.
AUDIO
AUGUST, 1975
95
www.americanradiohistory.com
FOR SALE
FOR SALE
GRAPHIC EQUALIZER PLANS: Novel circuit very effective/inexpensive, requires no inductors. Ten knobs (octave
bands) compensate your Hi-Fi/Tape providing better listening. Complete plans rushed only $3.49. GREEN BANK SCIENTIFIC, Box 100C, Green Bank, WVa. 24944.
DUTY GREEN RECORD SLEEVES
78
for free samples & price list. GREENSLEEVES,
423 Greenway Ave., Trenton, N.J. 08618.
rpm-Send
YOUR ROOM IS THE MISSING LINK
listening environment, and therefore a rip-off. Our acoustical
consulting division will have a calibrated "reverberation
curve vs. frequency" measurement performed in your room,
and our engineering dept.'s plan of correction, loudspeaker
placement and room equalization, all at no cost with your
purchase or upgrade. Music & Sound Ltd., 11'h Old York Rd.,
Willow Grove,
THE AUDIO RESEARCH ROOM. The complete line of Audio Research equipment on display under ideal listening con-
ditions. AUDIO SYSTEMS & DESIGN, 5421 South 84th St.,
Lincoln, Nebraska 68516 (402) 489-9888.
AMPEX TAPE-NEW 1800' on 7" reel 12 for $18 POSTPAID; 1200' 12 for $13 POSTPAID-free list-WIDE RESPONSE, 6114A SANTA MONICA BLVD., HOLLYWOOD. CA.
90038.
ELECTROENCEPHALOPHONE: brainwave monitor, Professional biofeedback instruments. J&J 8102-A, Bainbridge,
WA. 98110.
I.
lieve! Send requests for equipment prices to Quality Sounds
of Maryland, Gerard White. Sales Manager. P.O. Box 63, College Park. Maryland 20742.
EARS: Hear Mag-
neplaner, Dayton -Wright, B&W, Audionics, Infinity Servos,
Braun, Quad, Ohm, Crown, BGW, Radford, Quintessence, Yamaha, Mark Levinson. Linn-Sondek, Transcriptors. Vestigal,
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fon, KMAL, Passive Crossovers, Transmission -Line Speaker
Kits, Basic Drivers. Shipped Pre -paid in most cases. AUDIO Uncommon, Inc. 8600 N.E. Sandy Blvd. Portland, Oregon
97220.(503)254-6202.
JAPANESE TRANSISTORS, Kit $23.44 contains 24 most
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BAY AREA AUDIOPHILES: AUDIO RESEARCH, AUDIONICS,
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Credentials
College instructors in audio /acoustics, Inventors/graduate electrical engineers, Recording & disc mastering engineers; Members: United Inventors & Engineers
Acoustical Society of America
Institute of Electronic Engineers
II. Facilities
Anechoic Chamber:>.971 working floor
$50,000 research laboratory
Factory authorized "A" warranty stations
Ill. Our Distinguished Suppliers
Audio Research, Sequerra, Satin, Transcriptors,
F.M.I./R.T.R., Linn Sondek, Nakamichi, Dayton Wright,
Dahlquist, Crown, Infinity, I.M.F., London Decca, Quad, Rogers, Spender, Stax, B&0, Grace, Supex, Micro Acoustics,
Custom Rabco, Braun, Revox A-700, Ortofon, Damped
S.M.E., Scully, dbx, Mark Levinson.
AUDIOPHILES! Quality Sounds of Maryland has came to
your rescue. Write to me for system quotes you won't be-
QUINTESSENCE,
Pa.
CONSIDER YOUR SOURCE FOR SOUND
NOW AVAILABLE. ... FAMOUS REFLECTING SYSTEM'S 41/2" REPLACEMENT DRIVERS. $7.98 POSTPAID. BIG QUANTITY DISCOUNTS. FREE SPECIFICATIONS. AURATONE, BOX 580-22A, DELMAR, CALIFORNIA 92014.
UNCOMMON
-45,
HEAVY
A state of the art system is usually junk in the typical poor
COMPETENCE IN AUDIO SINCE 1928!
Qualified service, custom installations
Klipsch, Sequerra, SAE, McIntosh, Levinson.
SME, Ortofon, Fidelity Research, Ampex
Professional, Tandberg.
We buy and sell quality used gear.
THE MUSIC BOX, INC., 58 Central Street
Wellesley, Mass. 02181. (617) 235-5100.
OREGONIANS WITH
FOR SALE
1000's of PROFESSIONAL products
(see Tuned Rock
P.A. ad).
Music & Sound Ltd., 11'h Old York Rd., Willow Grove,
Pa.
IN PURSUIT OF EXCELLENCE WE OFFER: Infinity, Crown,
Renos, Fulton, Sennheiser, Philips, Ortofon, ESS, SAE, Beyer,
DBX, Altec, Technics direct drives, RTR, McIntosh, JBL, Tran-
scriptors, Klipsch, Citation, Decca, SME, Sequerra, Micro/Acoustics, Lamb, Dahlquist Tannoy, Yamaha, Sound craftsmen, Marantz, and more...Also custom room equalization, individually damped Altec & JBL Monitors and an ongoing equipment evaluation program. The House of Sound,
821 Kent Ave., Baltimore, Md. 21228.
COMPONENTS FOR THE CONNOISSEUR
LOUDSPEAKERS: Audio Research T -3A
B, Braun LV
1020, Dahlquist DQ10, Dayton -Wright XG-8 MK11B. ESS,
Fulton J Modular System, Hartley Concert Master, Hegeman
1A & 2, Magneplanar M62167 -F, RTR 280 DR, ESR 6, 15.
COMPONENTS: Audio Research, BGW, Burwen, Connoisseur,
Dayton -Wright Hervic, Linn-Sondek, M&K super woofers and
crossovers for T-3ATM, 18, etc., Mark Levinson Products, Ortofon, Panasonic SP 10, Quad. Quintessence, Radford, SAE,
1
Shure, SME, Supex, Thorens Transcriptor and SEQUERRA.
Brochures available.
PAUL HEATH AUDIO
354 STATE STREET
14608
(716) 232-2828
ROCHESTER, N.Y.
HONG KONG, TAIWAN, JAPAN, Asia Directory. World
products information. Mail -orders, bulk -orders. Listings. Directory and Information $1.00 today. World Trade Inquiries.
Box
6224, Spokane, Wash. 99207.
HIGH PERFORMANCE
HIGH FIDELITY WITHOUT THE
"HYPE". Suffolk Audio takes a rational, no nonsense viewpoint on high performance audio equipment. Our advice and
opinions are based in objective fact, not mythology and folklore. All equipment is pre -tested for maximum performance.
Our distinguished suppliers include: Allison Acoustics, Bow-
19090. (215) 659-9251.
Whom Would You Trust?
ers and Wilkins, Quad, Linn Sondek, Decca, Mark Levinson,
THOUSANDS OF LIKE NEW LP's and prerecorded tapes.
Catalogue 51.50. House of Records, Hillburn, New York
10931.
A-700 series), KMAL, Ortofon, BGW Systems,
Radford, Beyer, Connoisseur, and much, much more. Call or
write for information.
Renos (incl.
RTR EXCLUSIVE PHILA. SHOWROOM All RTR Speakers
SUFFOLK AUDIO, INC.
1105 Mass. Avenue
demo including the new 1600E, 280DR/ESR15's. Two
Cambridge, Mass. 02138
on
and three way electronic cross overs. Don't buy any speaker
until you've heard RTR. Appointment 215-667-3048; 503
Haverford Ave., Narberth, Pa. 19072.
AUDIO RESEARCH, AUDIONICS, BANG&OLUFSEN, BOZAK,
CROWN, DBX, KLIPSCH, KMAL, LINN SONOEK, NAKAMICHI,
PHASE LINEAR, RADFORD, REVOX, SEQUERRA STAX, TAND BEYER, SENNHEISER, and other fine instruments for
the reproduction of music. Send for list of top -grade used
equipment AUDIO SYSTEMS AND DESIGN, 5421 South 84th
St., Lincoln, Nebraska 68516 (402) 489-9888
and
BERG,
....
4408 Capital Ave., Omaha, Nebraska 68131. (402) 5567559.
Ph.
(617) 868-1080.
PROTECT YOUR LPs. Poly sleeves for jackets 8c round bottom inner sleeves 6c Poly lined paper sleeves 15c White
jackets 30c Postage $1.00. House of Records, Hillburn, New
York 10931.
NEW YORKERS-WE ARE COMMITTED!
Consult with us about your audio needs. We have what you
want, we offer FULL service.
IMF, BGW, SAE, OHM, INFINITY, KLIPSCH, ORTOFON, THORENS, SME, LEVINSON JC-1, STAX, ADS -BRAUN, TECHNICS,
PIONEER, KENWOOD, SOUND CRAFTSMEN, DBX, REVOX and
Many Others.
SHURE, SUPEX, TANDBERG, WIN LABS, McINTOSH (USED).
Compare any of our products through our switching device
CONN. AND WESTERN MASS-FRED LOCKE STEREO offers Accuphase, Epicure, Crown. Quatre, Audio Research,
INNOVATIVE AUDIO
129 DeGraw Street
using 1/1 Mark Levinson master tapes at GARLAND AUDIO,
Phase Linear, SAE, Citation, Mark Levinson, Soundcraftsman,
2960 Stevens Creek Blvd., Suite 0. San Jose, Calif. 95128
(408) 244-6724.
ESS
Brooklyn, NY 11231
(212) 596-0888
Call For Appointment
DYNACO KITS, big discounts, All Kits, Box 864, Dentin,
Florida 32541.
PAIR JBL HARTSFIELDS $550.00 each. JBL SE400S amp
$225.00. JBL SE401 energizer $195.00 Frazier S.E.E. 24
equalizer $350.00. Ortofon SL15 cartridge/Martin pre -amp
combination $95.00. Peter Miccolis, 1701 E. Tulip St., Phila.,
Pa. 19125. (215) 426-4000.
101/2" RECORDER SPECIALISTS: Fresh new Scotch
3600 ft.
on new
/"
L/N
NAB metal reels five for $35.00. New
Ampex GRANDMASTER tape on 101h" metal reel, six for
$73.00. New 4 channel 8 -track blank cartridge loaded with
40 minutes Scotch L/N tape, $23.00 per dozen. Reconditioned NAB metal 101/2" reels, $24.00 per dozen. 10%
on above for postage. Sound Investment, POB
woody,
Ga.
88338, Dun -
30338.
CENTRAL NEW YORK HI-FI ENTHUSIASTS-Britain's finest
loudspeakers
AND
ALS40-as well
on
demonstration-THE IMF STUDIO
as Marantz,
Pioneer, Renos, Beyer,
...
Epicure (3 lines), Thorens, Ortofon, XLM, Discwasher
SOUND SHOP, 96 Seneca Street, Geneva, N.Y. 14456
781-0215.
THE
(315)
(including bi-amped Towers), Magneplanar, Thereon,
Technics, SME, Ortofon, Supex, Fidelity Research, Revox,
Tandberg, Teac, Transcriptors, OBX, Beyer, Stax, AKG, Nakamichi, Sequerra, Burwen, Hartley woofers, and others Avon
203-678-1797; East Hartford 203-528-9479; New Haven
203-787-0183; Waterbury 203-757-9296; Fairfield 203366-5246; Springfield, Mass. 413-782-7111.
REVOX A-700,
$1350-excellent condition,
one year old.
1-313-689-5300.
ARIZONA AUDIOPHILES
Crown
S.M.E.
Burwen
Stanton
*
*
J.B.L.
*
*
*
E.S.S.
*
Grace
*
*
*
Rabco
*
Uher
Accuphase * S.A.E. * Revox
Stax * Tandberg * Magnepan *
* Sequerra * Bose * Thorens *
Klipsch * Phase Linear * Sennheiser
Sony V-F.E.T.
Nakamichi * Yamaha
*
*
Beyer
*
Jennings Research
JERRY'S AUDIO EXCHANGE
MARANTZ
7
preamp, model 9 amplifier,
1OB tuner
with
Marantz cabinet. All absolutely brand new, never used, in
original cartons with all material. Please submit offer. H. Meyer, 116 Gramatan Ave., Mt. Vernon. N.Y. 10550.
MIDDLE & NORTH JERSEY AUDIOPHILES - Stereo
Sound of East Hanover offers personal, friendly service and
"state-of-the-art" equipment: Quintessence, RTR, SAE, Ortofon, Transcriptors, Stan, Bang & Olufsen, Phillips, Crown,
McIntosh, IMF, JBL and more. Full demo & service facilities
for our customers!!!
Stereo Sound
320 Route 10
East Hanover, N.J. 07936
201-386-0050
-334
E.
Tempe -130
E.
Phoenix
Camelback Rd. 85012 602-263-9410
University Dr. 85281 602-968-3491
Tucson -1037 N. Park Ave. 85719 602-622-7407
ARC SP-3G, case, $525. BOSE 901's, deluxe, $400. SAN E -V T-3500 Inovac, $100. All mint,
FOB.
SUI GS -1, $65.
Want ALTEC Acousta-Voicette. 703-243-0515 after 7:30
PM.
HIGH DEFINITION SUPERWOOFERS - The world's finest
woofer systems -The Hartley 24 inch and 18 inch high power
woofers in an optimized transmission line. Available only
through Hartley Electronics. 1502 Butternut. Richland, WA
99352. Phone: (509) 946-4459 and 947-5026 after 5:00
PM.
AUDIO AUGUST,
96
www.americanradiohistory.com
1975
FOR SALE
FOR SALE
FOR SALE
INFRA WOOFER TM world's largest, deepest, most powerful
sub -woofer system can be had only at Music and Sound, Ltd.
50 dB per octave crossover, bandpass 16 hz , , $1295.
STEREO
NEEDLES AND
GRADO EMPIRE,
CARTRIDGES -ADC,
B&0,
Listen to
TELEVISION
MICRO -ACOUSTIC, PICKERING, ORTOFON,
.
F.M.I. &
I.M.F. SUB-WOOFERS, for the closest approximation to dipole definition -$180-$350! Also, the
rave five -way Fulton/R.T.R. super speakers. Shipped prepaid/insured. Music and Sound, Ltd., 1111 Old York Road,
Willow Grove,
Pa.
19090 (215) 659-9251.
AKG, ALTEC, AUDIO RESEARCH, Beyer, CROWN, DAHLQUIST, DBX, DECCA, INFINITY, KLH 9s. Koss, Mark Levinson,
Nakamichi, Orofon, PHASE LINEAR, PML, REVOX, SAE,
Sennheiser, Sequerra, Sony, Stanton, Stax, Supex, Tandberg,
TASCAM, Technics, Thorens, etc.
HI-FI HAVEN
28 Easton Ave.
New Brunswick, N.J. 08901
201-249-5130
DISCOUNTS ON L.P.'s, cartridges, cassettes, "singles."
Stereo and Quad, all labels all artists. No fees, no gimmicks.
Same -day service, postpaid. Send stamp for free details and
B IG
Schwann Basic Record Library pamphlet listing 1000 pieces
of classical music arranged by musical period and composer.
Or, send $1.00 each (refundable) for Schwann Record and
Tape Guide; Harrison Tape Catalogue; or "Golden Oldie" singles catalogue (listing over 5000 45 RPM's). DISCO -TAPE
UNLIMITED, Mail Order Dept. AO, Box 817, LaPlace, La.
SHURE, STANTON, SUPEX, SONY, PANASONIC, RCA, BSR,
Washington.
D.C.
20041.
CANADIANS: Shure M91E0 $24.88; Dynaco A25 $68.00;
Pioneer SX424 $179.95; Dual 1216 $119.00; Leak Delta
75 $289.00; Garrard Mini changer $13.99. Free Hi-Fi discount catalog. Etco (Au), Box 741, Montreal H3C 2V2.
N AME
BRAND RECORDING TAPE, custom loaded. Avail-
-
manufacturer.
WESTCHESTER HEADQUARTERS for the great sounds in
the world. Quad, Ohm, Cambridge, Dahlquist, Bose ESS,
Braun, SAE, EPI, Crown, Phase Linear, Tandberg, Thorens,
Yamaha, Nakamichi, Technic, BGW, Dual, Revox, Kenwood,
Pioneer. The Listening Room, Inc. 590 Central Ave., Scarsdale, N.Y. 10583 (914) 472-4558.
QUOTATIONS on all major components and musical instruments. No fair trade in Nevada, Lowest Prices. Southern Nevada Music Co., 2295 E. Sahara Ave., Las Vegas, Nevada
89104. (702) 457-4558.
AT LAST! The high -output version of the highly regarded
SUPEX SD -900 is now available in the U.S. The SD -901 will
work directly into any pre-amp. $145.00. For name of Dealer
nearest you write to Sumiko, Box 5046, Berkeley, Ca.
94705.
LOOKING FOR THE BEST in High Fidelity? Try The Id. We
feature lines such as Accuphase, Crown, Yamaha, Sansui,
Thorens, Dual, P.E., ESS, Bozak, Altec, Ortofon, Stanton &
Stax headsets. For more information call or write:
The Id
2219 Frederka St.
Owensboro, Ky. 42301
Phone (502) 926-2765
95125.
DISCOTHEQUE MIXERS from $325, equalized speakers
with built-in power amplifiers, bi-amped systems, and comDealer inquiries invited. GLI, P.O. Box 2076, Dept. A. Brooklyn, New York 11202.
DEALERS: We will buy your excess stock. ALL lines, no
quantity too large or small. Cash paid immediately. Call M.
Gasman
617-924-0561.
TURNTABLE OWNERS. Add cueing. Precision machined. Silicon damped. American made. $16.00, postpaid.
lyrelift, 582 Franklin Street Cambridge. Mass. 02139
AR
AUDIO'S HI-FI HANDBOOK
Complete reference guide to over 1,000 components, including prices and specs. All arranged in tabular form for
easy comparison. Plus over 30 outstanding articles on audio
topics, trends and advances. State-of-the-art reading for audiophiles. Only
a
limited quantity available. Over 200 pages.
Send $3.95 (includes shipping and handling) to: Jean Davis,
Audio Hi-Fi Handbook, 134 N. 13th St., Phila., Pa. 19107.
MILWAUKEE & WISCONSIN'S only audiophile dealer.
Specialists in components by Crown, Dahlquist Transcriptors,
DITTON 66 Studio Monitors, $650. ERA
Mk6/Vestigal, $185. Radford SPA60, $275. T. Martin, 5131
Starlight, Racine, Wisc. 53402.
Integral Systems, Epicure, Nakamichi. Bozak, Citation, Ohm,
SME, Ampzilla, DBX, Infinity, SAE, RTR, ESS, Reyes, Phase
Linear and 50 others. Wisconsin's only Audio Research dealer with the entire product line on demonstration. WACK
ELECTRONICS INC., 5722 W. North Ave., Milwaukee 53208.
FAMOUS MAKE PIANOS AND ORGANS shipped prepaid
414-442-3441.
CELESTION
anywhere
at tremendous
saving. State make and model
-SPEAKER CATALOG
wanted for our quotation. File this advertisement for future
ONE MONTH NEW! Phase Linear "Brute" System
-
4000
and 7006 with walnut cabinets. Sacrifice for $1250. Please
call (602) 968-6644 after 7 P.M.
DYNACO STEREO 400, PAT -4, PAT -5, FM -5. One each.
Factory aligned after assembly. Brand new, never used, origiKit price, plus shipping. Delivered
Northeast, or 25% down, balance COD. Box A57-2, Audio.
nal cartons, warranties.
ORIGINAL TRANSCRIPTOR HYDRAULIC REFERENCE
TURNTABLE (do not confuse with smaller "Skeletal"
table/Vestigal arm package from Ireland) now available direct from U.S. importer. Magnificent turntable complete with
silicone -damped Unipivot arm, $498.00 freight prepaid.
Without arm, including blank arm -mounting board or one cut
for SME, $398.00. Send $100.00 down for COD shipment.
Audiophile Imports,1O East Erie, Chicago, 60611. (312) 7870754.
DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES
WAREHOUSE OF BETHESDA, P.O. BOX 34251, WEST BETHESDA. MD.
20034.
AUDIO
-
to date. Top quality drivers. Hop -up the speakers you
have or build new ones. Transmission -line speaker plans
212 462-0984
Foam damping material
$5.00
4.1p
reference. Greenwich Music Center, Greenwich, N.J.
or
-
....
TEXAS AUDIOPHILES! On demonstration: Dahlquist Nakamichi, Transcriptors, Linn-Sondek, Infinity, Braun, Advent
Crown, Phase Linear, Ortofon, Levinson, Supex, Quad,
Klipsch, IMF, Keith -Monks, ESS, Decca, B&0, Radford. Stax,
Audionics, Philips, Revox, Citation and many others. Audio
Concepts, 2021 Guadaloupe, Austin, Texas. Phone 512-478-
7421.
HI-FI ENTHUSIASTS WANTED!! Earn more than just spare
money in your spare time. We need campus representatives
to sell name brand stereo components at discount prices in
your area. High commission, no investment required. Serious
inquiries only, please. Contact: Alan Weisberg, K&L Sound
Services Co. 75 N. Beacon St., Watertown, Mass. 02172.
CAN YOU IMAGINE a magazine that recommends components in four categories from no -holds-barred to best-for the -money? The Stereophile does it. For info write Box 49A,
Elwyn, Pa. 19063.
AUGUST, 1975
'LI
$5.00 for C.O.D.
TO: RHOADES NATIONAL CO. DEPT AO
P.O. BOX 817 HENDERSONVILLE, TENNESSEE 37075
NAME
Sound, State of the Art Components for the Experienced Listener. 8719 Wilshire, Beverly Hills, California 90211.
MJS, 516 Brooks, San Jose, Calif.
plete portable discotheque systems. Write us for literature.
.
SUE OWNERS
Completely rebuild and modify
your SL8E to be the finest tone arm available today. Space
age precision and machining, new light -weight tone arm. Unbelievable tracking and reproduction. $250.00. Jonas Miller
RABCO
able in cassettes, reels, and cartridges. Huge savings direct
from
The TE.200 TELEDAPTER EASILY CONNECTS TO ANY TV &
STEREO SYSTEM. Using our coupling and matrix circuit, teledapter takes
a low
impedance output from the television and delivers two HIGH
IMPEDANCE CHANNELS OF SIMULATED STEREO, to drive any
amplifier. Frequency response is maintained so you can Mar the tinkle of
bells or booming bass sounds as it happens on TV. With tern.. warranty
and hookup instructions 51695 ppd. Guaranteed to make your TV 100%
rnare enjoyable.
OUR NEW TE.300 VHF -UHF HI-FI TUNER IS NOW AVAILABLE. A
complete and self contained 110 volt toner. VHF -UHF antenna connecRecording and amp output jacks. Five year terra warranty
tions
$149.95 ppd. From our factory.
TE.2001JTE300
CHECK LI MASTER CHARGE NO. for
SEND-
NOW IN PRODUCTION: World's heaviest 12" woofer. 17Hz
resonance. Over 200 watts RMS. Sand cast frame, $59.00
delivered U.S.A. Rockwell Systems, Inc., 100 Liberty St.,
Rockwell, N.C. 28138.
70068.
PIEZO SUPER HORN TWEETERS $7.95 P.P. Cont. U.S.A.
Daily Mfg. Co. (Mfr. of quality loudspeaker systems since
1951), 100 Liberty St., Rockwell, N.C. 28138.
IN STEREO
and others. NEEDLE IN A HAYSTACK, INC., P.O. Box 17436,
ADDRESS
STATE
CITY
ZIP
PREAMPLIFIERS, ELECTRONIC X-OVERS,
MIXERS, etc. Engineered to meet most stringent performance parameters. Call or write for additional information: OHRWERKE, 40 High Street Guilford, Conn. 06437, (203) 399CUSTOM
7367.
N EW PRODUCTS: Allison Acoustics; Koss Full Range Elec-
trostatic loudspeakers; G.A.S. (Ampzilla) amps, preamps;
Quatre; Rabcó s ST -7 turntable; Muntz Home Theatre Color
Television
)30"s40") screen. USED
MINT:
ARC -075k
50F1 B; Burwen 1201; Citation 12; Crown IC150, 0-60, 300;
Labs; Hervic receivers; Hewlett Packard amp; ESS amp;
C -M
60M's; SAE Mark 1M, IIIC; BGW 500R; Radford
SC242, SPA60; IMF Monitors, IIIA's; Hartley Concertmasters;
ESS AMT -1; RTR 400E RTR ESR-6, 15; FMI 80, 120; Teac
7030 GSL. Paul Heath Audio, 354 State Street, Rochester,
Paoli
N .Y.
14608. (716) 232-2828.
ATTENTION
WESTERN NEW YORK AUDIOPHILES
The word is getting around!! Our personalized, honest service
and quality equipment make a winning combination. In addition to the incomparable AUDIO RESEARCH line, (T-1B's
black/natural in stock), we carry AMPZILLA, SAE Phase Linear, Yamaha, Quintessence, LEVINSQN, B&0, IMF, MAGNE
PAN, M&K Subwoofers, Hegeman, Infinity, RTR, ESS, DAHIGUIST, Fulton Music, QUATRE, Onkyo, Connoisseur, Technics,
Thorens, Dynaco, Transcriptors, Cerwin Vega, Sound craftsman, Supex, Ortofon, ADC, Micro -Acoustics, Damped
SME Linn Sondek, KMAL, Naim Audio, etc. The Stereo Emporium, 3407 Delaware Ave., Buffalo, N.Y. 14217. (716)
874-3372.
TRANSIENT OUTPUT MONITOR for audio amplifiers.
L.E.D. readout indicates 1Vt to 1000 watts average and transient power output. Hand assembled, calibrated, tested.
$100. Free literature. Analogic Design, P.O. Box 7753, Nhila.,
Pa.
19101.
ROGERS B.B.C. MONITOR, B&W Ltd., Celestion, Radford,
Decca, ERA, Connoisseur, Audionics TL -90, Goldring, Revox,
Beyer, Lamb and more. Custom design and modifications.
SUFFOLK AUDIO, INC. 1105 Mass Ave., Cambridge, Mass.
02138 (617) 868-1080.
ADC,
SAN DIEGO, CALIFORNIA
Advent AKG, AR-LST, Audio -Research, BGW, Citation,
Crown, Dahlquist DBX, Dynaco, FMI, Janszen, Linn Sondek,
Magneplanar, Marantz, Micro -Acoustics, Ohm, Phase Linear,
Philips, Quintessence, Rabco Revox, RTR, Sennheiser, SME,
Stax, Supex, Tandberg, Yamaha.
Sound Company
4701 College Ave., (714) 582-4148
3675 Sports Arena Blvd., (714) 224-2844
THE FIRST (1962) UNDERGROUND audio publication of
them all, the Stereophile is the subscriber -supported perfectionist's magazine the others are trying to imitate. Free
dope sheet explains why. Box 49A, Elwyn. Pa. 19063.
WESTCHESTER
AND
FAIRFIELD
COUNTY
AUDI-
OPHILES TAKE NOTE! THE AUDIOPHILE, 231 BEDFORD
STREET, STAMFORD, CONN. specializes in equipment for
the connoisseur. Ampzilla, Audio Research, ADC, Citation,
Crown, Dahlquist, Dyna, Epicure, Infinity, Philips, SAE SME.
Stax, TEAC, Technics, Thorens and many more (203) 3483551 (Closed Mondays).
97
www.americanradiohistory.com
FOR SALE
FOR SALE
TARZAC
CASSETTES: C-1 thru C-90. CUSTOM CASSETTE LABELS. Free samples. 638 Muskogee Avenue, Nor-
LUCKY OWNERS
DYNA PAS -3(X)
INFINITY 2000A
DECCA MKV AND "EXPORT"
DYNA MARK III
SHURE SME and
other tabular tonaarats
free blurb sheet.
20kHz!) Literature and price information available upon re-
Ph.
UNIQUE MODIFICATIONS ENGINEERED SPECIFICALLY
FOR THESE COMPONENTS. NOW YOU CAN GREATLY IMPROVE THE SOUND QUALITY TO
here! Our MCP -1 Moving Coil Cartridge Preamp, featuring audible superiority at a reasonable price, is now available. For
information write R B AUDIO, P.O. Box 574, Eatontown, NJ
"ULTRA DEFINITION".
RTR, INFINITY, BOSE, ESS, KLIPSCH,
SAE, CROWN, PHASE LINEAR, HERVIC, CITATION, YAMAHA,
BURWEN,
BEOGRAM
TO
$170.00,
4002,
THORENS,
LINN SONDEK, TECHNICS. TRANSCRIPTORS. PHILLIPS, CONNOISSEUR, A&D, SME, REVOX, SONY, ADC, ORTOFON,
SHURE, MUCH MORE.
STEREO CENTER
2539 VESTAL PKWY. EAST
VESTAL, NEW YORK 13850
(607) 729-6191
OUR
MODI-
IMPROVEMENTS
INFORMATION CONTACT:
SEVERNA PARK, MARYLAND 21146
OR CALL: (301) 588-6257
MONDAY, WEDNESDAY, THURSDAY,
SATURDAY 2-8 PM
rens, S.M.E. etc. all accompanied by Fred Huggins himself.
QUINTESSENCE.
$25.00
DKL LABORATORY, INCORPORATED
BOX 683
the complete Audio Research line, Polk Audio Model Nines,
ESS Heils, Janszen, S.A.E., Altec, Citation, R.T.R. B&0, Tho-
DAHLQUIST DO -10,
FROM
FOR MORE
BALTIMORE-WASHINGTON AREA AUDIOPHILES REJOICE! At last a store for you. Come to Myriad Sound and
hear the finest in state of the art audio equipment. Featuring
Main store at 9619 Reisterstown Rd., Garrison, Md. 21055
(2 miles North of Balt. Beltway exit 20) (301) 363-1733.
"ULTRA DEFINITION" SOUND
SYSTEM. CHOOSE FROM THE WORLD'S FINEST COMPONENTS LIKE:
HELP YOU CREATE YOUR
AUDIO RESEARCH-electronics and speakers
BGW-power amplifiers
DBX-noise reduction systems, dynamic range enhancers
"HAND -TUNED" DECCA MKV-cartridges
DYNACO-tube electronics
FULTON-regular and MODULAR speakers
HK CITATION -amps, tuners
IMF -"MONITOR -ORIENTED" speakers, kits, sub -woofers
LINN-SONDEK-turntables
MAGNEPAN-speakers
S.M.E.'s-$30.00 For Rabco SL -8(E)-$100.00.
Transcriptors-free ('with purchase).
M & K -sub -woofers, matrix systems
PAOLI-tube amplifiers
RASCO-turntables
RTR-electrostatic speakers
SOUNDCRAFTSMEN-pre-amps, equalizers
NOW
LISTEN to our calibrated Satin Ortofon/Supex moving coils.
B&O/Grace/Micro-Acoustics. From the laboratories of Music
& Sound Ltd., 111/2 Old York Rd., Willow Grove, Pa. 19090
(215) 659-9251.
+Levinson Cartridge Preamp+
NORTHERN N.J.'S FINEST AUDIO STORE, 20 minutes
from NYC. Ampzilla, Bozak, B&O, Magneplanar, Phase Linear,
DBX, IMF, Oahlquist, Ortofon, Quintessence, Thorens, Pioneer,
Kenwood, Dual. Write or call - University Stereo. 57 E. Ridgewood Ave., Ridgewood, N.J. (201) 447-5700.
STAX-electrostatic headphones
"SUPER SHURE" SME-tenearms
TANNOY-turntables, speakers
AND SCORES MORE,
WASHINGTON D.C., MARYLAND, VIRGINIA
AREA RESIDENTS TAKE NOTEYOUR "STATE-OF-THE-ART" DEALER IS:
DKL SOUND LAB
ADS
SILVER SPRING, MARYLAND 20910
Quintessence
Nakamichi
Cambridge
M&K
Hours: MONDAY, WEDNESDAY, THURSDAY,
SATURDAY 2-8PM FRIDAY BY
Quad
APPOINTMENT ONLY, CLOSED TUESDAY
C/ M Labs
Braun
(301) 588-6257
Radford
Quatre
Hervic
Fulton
Revox
Audionics
Grace
Supex
Magnepan
Connoisseur
Dbx
Linn-Sondek
KMAL
Klipsch
Dahlquist
STEREO WORKSHOP
2985 College Avenue
Berkeley, California 94705
STATE-OF-THE-ART comes to NORTH -CENTRAL FLORIDA,
serving you with: AUDIO RESEARCH, BGW, Citation, Dahlquist, Dynaco, Hartley, Infinity, Magneplanar, Mark Levinson,
Ortofon, Rabco, Revox A-700, SME, Supex, Thorens, Transcriptors, and $10,000 worth of test equipment for in-store
audio analysis. We maintain a mobile recording van and sell
professional recording equipment. AUDIO, ETC., INC., 1999
N.W. 43rd Street, Gainesvlle, Florida, 32605. 1-904-377-
4107.
open 2-8 TWThF; 12-6 Sat
MIXER MODULES -Modules designed to provide
an
eco-
nomical route to studio -type mixing consoles. Modules have
plastic element slide faders and a module for E.Q. At last
there is a bridge between the high -cost pro gear and components for the audio enthusiast. Send for free info to Wall
of Sound, Box 239, Glen Burnie, Maryland 21061.
DON'T PAY THE HIGH MAIL ORDER PRICES THIEVES
OF TAMPA, 1531 SOUTH DALE MABRY, TAMPA FLORIDA 33609.
WAREHOUSE
-
High Quality Audio Has Finally Arrived!
Audio Research, Bang & Olufsen, Klipsch, Audionics, Ampzilla,
Radford, Revox, Bozak, Crown, DBX, Sequerra and others ...
opening June 1st ... THE SOUND ENVIRONMENT, Butler
Square, Suite 114, 100 North Sixth Street, Minneapolis,
Minn. 55403, (612) 339-4641.
DYNACO RACK MOUNTS for pre -amps, tuners, integrated
amps. S24.95 postpaid, $22.50, three or more. AUDIO BY ZIMET, 1038 Northern Blvd., Roslyn, N.Y. 11576 (516) 621-
PAOLL LINN SONDEK, Quatre, Revox, Ortofon, Dyne, SME,
Mark Levinson, Supex, Decca, Stax, Thorens, Hartley, Koss
Electrostatics, Epicure, KMAL,
B&W,
B&D, Dahlquist,
Braun,
Tandberg,
Transcriptors,
Nakamichi,
Micro Acoustics, IMF, Cambridge, Sony, Grace, others. Testing
of equipment and home consultation done by appointment.
Audio Workshop, Inc., Latham, New York (518) 783-9810.
MCINTOSH 2105 amp $500; McIntosh C-28 preamp $425;
Phase Linear 700 $550; JBL Lancer 55's $380. All like new.
Joe Cangelosi. (215) 258-2511.
AMPZILLA, built from kit, no problems. $425.00. Dahlquists, 6 months old, $625 pair. Call 1-301-838-7398.
LOW NOISE RESISTORS- r/4W,5%carbon film from 103.3 Megohm for 31c each. Fifty per value is $1.25.
1N4004, 1N4148 diodes. Postage 75c. COMPONENTS CEN10038.
TER. Box 134A, New York, N.Y.
JBL SE401 Amplifier, equalized flat or for 001
$110 (614) 888-5316 after 9:30 P.M.
system,
J8L 1,X10, 1217-1290; Dynaco ST120, PAT -4, AF-6;
Seundcraftsmen PE2217. Stanley Cudnik, 720 Pennsylvania
Ave., Trenton, New Jersey 08638.
LISTEN, distortion down to .01%, power up to 250 Watts
RMS. Amps and preamps, sound modifiers, synthesizers, digital stuff and much more, for less. Free Catalog. Digitronics
Co., dept C2, 667 East 1700 South, Orem, Utah 84057
943 BONIFANT
BERKELEY, CALIFORNIA
Mark Levinson
(415) 843-5836
07724.
MINNEAPOLIS
is
0138
WE SPECIALIZE IN ONLY THE FINEST SOUND COMPONENTS-ALLOW OUR STAFF OF AUDIO EXPERTS TO
PROPRIETARY CUSTOMIZED MODS reduce tone arm
friction, damp spurious resonances, minimize torsional forces,
improve tracking, and reduce record wear. For
For
399-7367.
MOVING COIL CARTRIDGE OWNERS: Your alternative
FICATIONS OFFER VAST AUDIBLE
AT REASONABLE COST.
(617) 868-1080
professional audio equipment. All merchandise guaranteed to
meet manufacturer's specification for 12 months (parts, labor, and round trip shipping included). Call or write
OHRWERKE, 40 High Sheet, Guilford, Conn. 06437, (203)
ED
PRICED
Cambridge, Mass. 02138
LOOKING FOR HIGH QUALITY "PREVIOUSLY OWNED"
MERCHANDISE? Referral/resale service for industrial and
THE DKL LABORATORY, INCORPORATED HAS DEVELOP-
quest.
SUFFOLK AUDIO, INC.
1105 Mass. Avenue
- Custom designed; fully tested; guaranteed
quality. Free brochure Write: Networks; Box 458; Placentia,
Calif. 92670
RASCO SLIME)
IF YOU BUY AUDIO EQUIPMENT you can't afford not to
read the Stereophile. Write Box 49A, Elwyn, Pa. 19063 for
high standard of uniform bass performance. New Convex Diaphragm Mid -Range and High Frequency drivers achieve
phenomenal wide dispersion (-3db 90 degrees off axis at
CROSSOVERS
OF:
DYNA STEREO 70
folk, Virginia 23509.
ALLISON ACOUSTICS LOUDSPEAKERS have stabilized
Radiation Loading. Years of intensive research by Roy Allison
(formerly of Acoustic Research, Inc.) on the interaction between loudspeakers and room boundaries has yielded a new
FOR SALE
ATTENTION,,,
BUY! SWAP! SELL! Your personal ad placed FREE in Audiomart, the audiophile's classified newsletter. Subscribe!
$4yearly. AUDIOMART, Box 821, Stratford, Conn. 06497.
A FEW competitively priced used Revox A77 decks available.
Completely reconditioned by Revox, virtually indistinguishable from new and have the standard Revox 90
day warranty for rebuilt machines. Satisfaction guaranteed.
Example A77 with Dolby for $675 plus shipping. Write
with requirements to ESSI, Box 854, Hicksville, N.Y. 11802
(516) 921-2620
-
DAYTON WRIGHT XG8, Mk Ill speakers. new cost $2500
sell 51700 (919) 467-9198.
AUDIO RESEARCH
SP -3 pre -amp. Excellent condition.
Transferable warranty. $475. Alan Heuss. 30 E. Kings Highway, Mt. Ephraim, New Jersey 08059.
SOUTH FLORIDA'S FIRST AUDIO RESEARCH DEALER.
Full Audio Research Systems on display: SP3-A/Dual
76/Dual 51 /Magneplanar Tympani I-B/Tympani IIIA' Plus
Advent, B&D, McIntosh, Marantz. Phase Linear, Sherwood,
Supex, Stax, SME, Sennheiser, Tandberg, Thorens, Technics,
Nakamichi, Mark Levinson, Sequerra, Fulton, Satin. Ampzilla,
Magnepan, Crown, Revox, AR. Complete audio counselling
and custom installations. Sound and Sight, 20 N. Federal
Highway, Boca Raton, 33432, (305) 391-1843; 141 Lakeview Avenue, West Palm Beach, 33401. (305) 655-2236.
-
STEREOPUS
A new quarterly
tells it like it is. Reviews equipment
sounds like, good and bad points, and
ciated equipment for which it is most
audiophile publication
an ear to what it
type of room and assosuitable. If you are into
audio, get into StereOpus. We won't let you down or leave
you to read between the lines. First issue available now, second upcoming soon. $9.00 (four issues): $11.00 (first class):
$12.00 foreign. StereOpus, P.O. Box 269. Fort Walton Beach,
Florida 32548.
AUDIO
98
www.americanradiohistory.com
with
AUGUST, 1975
FOR SALE
FOR SALE
FOR SALE
Technics SL -1300 turntable/Stanton 681EEE $285.00.
Magnum Opus acoustic suspension-piezoelectric loudspeakers
$335.00 pr. J.V.C. VR5551 Receiver 130 watts rms, equalizer, more $365.00. All equipment 1 month old, factory cartons, warranties. Danny, (516) LY3-7048, 199 Union Ave.,
Lynbrook, N.Y. 11563.
A RARE FIND: Electro -Voice 2A receivers. 27/27 watts
rms. Fine tuner, 0.1% I.M. and T.H.D. distortion. You will never find a receiver of such quality at this price. $120.00 All
shipped prepaid/insured. Lesmeister Co., 3619 Wheeler,
#230, Dallas, Texas 75209.
TDK, BASF, Memorex, Maxell, cassettes, reels, 8 -tracks.
Lowest Prices, Guranteed, New. S&S Audio P.O. Box 56039
DISCOUNT
cartridges, receivers, speakers, amplifiers,
car radios. Free catalog. Stereo Habitat, 481 - 3 Ave., NYC
Radford Electronics, Hartley Loudspeakers (full line on demonstration and 24 inch woofers in stock), G.A.S. Co. (Amp -
10016.
zilla), Quad, Audionics, Supex Moving Coil Cartridges (new
RTR Electrostatic Tweeters
-
18 3" x 6" panels, two
power supplies. Best offer over $200. George Pro, 1618
Park Towne Lane N.E No. 5 Cedar Rapids, Iowa 52402.
AMPZILLA, TRANSCRIPTORS, Magnepan. Now available
in West Michigan. The Music Center, Hastings. (616) 4572117.
BUY
ENGLAND'S HI-FI MAIL ORDER
DIRECT FROM
SPECIALISTS! Save
B&O, Celestion, Decca, Tandberg,
Revox, Transcriptor, Jordan -Watts, Lowther, KEF, Rogers,
SME, Ariston, HPD, Sugden, Radford, Neal, Ferrograph, etc.
on
Shipping lists free or send $3.00 bills to include literature.
Goodwin Ltd., 7 Broadway, Woodgreen, London N.22. Phone
01.888-0077. Visitors welcome.
SURPRISE! SURPRISE! Digital Piano Tuning Device tunes
musical instruments Accurately! Perfectly! Inexpensively!
Construction-Instruction Plans Complete $12.95 Airmailed
Postpaid! Moonlighting quickly repays $40 electronics investment! GREEN BANK SCIENTIFIC, Box 100E, Green Bank,
WVa. 24944
MARANTZ 250 power amplifier $299. Marantz 1030
w/cabinet $110. Marantz Imperial 7 speakers $240 pr. Dual
1218 with base $100. Sold separately or together. Total
system price $700. System one year old. S. Burton, 1607
Oak #115, Denton, Texas 76201.
-
MAGNEPLANAR TYMPANI IIIA's, Audio Research EC3-A
electronic x -over, Ampzilla, two (2) each Audio Reasearch
Dual 76's. Call (704) 364-4455.
IAD DYNAMIC EXPANDER Compression is distortion,
eliminate it! The Dynamic Expander has unmeasurable distortion, S/N 103dB down, LED expansion indicators, smooth
expansion and decay adds up to +20dB in program material
without embarrassing pumping, breathing and veiling for all
who listen. Advanced engineering and esthetic design for the
most beneficial addition to any system. $265.00 Dealer inquiries invited. IAD, 10 East Erie Street, Chicago, Ill. 60611
SAE Mark 1B cad Mark IIICM. New. Guaranteed Perfect.
$1.368.75. Reply Box A58-1
DYNA STEREO 70 MOD KIT. Tighter bass, improved transient response, higher definition. Complete instructions, schematics, parts list, $5.00. With parts kit including all new
tubes, $46.00. Or we will modify $105.00 all postpaid. Audio Designers, Box 122, Ledyard, Conn. 06339.
DYNACO STEREO 400, PAT 4, B.I.C. 980, (617) 888-4846
TWO MCINTOSH 75 watt amps, excellent condition, $80
each, $150 pair. Crown 822 recorder $400. Eight assorted
P.A. mica $50. Bogen MXM-A mixer $75. R. Garecht, 146
Luzon Dr., Ft. Bragg, N.C.
ST. LOUIS' LEADING QUALITY AUDIO DEALER -Featuring
the following equipment:
AUDIO RESEARCH
ACCUPHASE
PHILIPS
AKG
QUAD
ALTEC PRO
QUINTESSENCE
B&O
REVOX 700
M&K
Audio Research
Quintessence
Techniques
Dahlquist
Gale
KMAL
Supex
Yamaha
Ampzilla
SME
Win Labs
Audionics
Nakamichi
SAE
Linn Sondek
Quatre
Braun
BOZAK
RTR
CITATION
SCULLY
DECCA
STANTON
EPICURE
STAX
GARLAND AUDIO. INC.
KMAL
LINN SONDEK
NAKAMICHI
TANDBERG
2960 Stevens
PHASE LINEAR
YAMAHA
(314) 647-8866
Since 1927
AUDIO RESEARCH 075G power amp (transferable warranty good for 3 more years) $600; Marantz 7C preamp with
case $200; Harmon Kardon Citation 12 power amp (with
warranty card) $200. Tom Jansen, 602-838-6651.
TWO NEW 15" ALTEC 604-E Super Duplex speakers with
dividing networks, 16 ohms. Price: $140.00 each. Michael J.
Kelly, 845 North First Ave., Kent, Washington 98031. Tel:
206-852-8944.
N EW! SUPER-HANDY EASY TO MAKE ADJUSTABLE STEREO
MICROPHONE HOLDER!
FOR
COMPLETE PLANS, DE-
SCRIPTION, SEND S2 TO: KAP, BOX 185, SOUTHAMPTON,
MASS. 01073.
FINEST
-
Audio Research, Audionics,
Braun, BGW, Burwen, Crown. Dahlquist, Dayton Wright, Decca, Fidelity Research, FMI, GAS, Hartley, IMF, Infinity, Linn
Sondek, Mark Levinson, Nakamichi, Quad, Quatre, Quintessence, Radford, Sequerra, Supex, Tandberg, Transcriptor,
Yamaha, also Custom Designed Superwoofers, and many
more. HARTLEY ELECTRONICS, 1502 Butternut, Richlpnd,
WA 99352. (509) 946-4459 until 6:00 PM, then 947-5026
evenings.
N ORTHWEST'S
Stax
DBX
Crk. Blvd.
(408) 244-6724
UHER
and others
Grace
San Jose, California 95128
TECHNICS
Equipment tested before being shipped prepaid.
J.C. Gordon Company
2831 Hampton Avenue
St. Louis, Missouri 63139
Fidelity Research
Mark Levinso,i
Connoisseur
Magnepan
Sequerra
Fulton
QUAD ESL, mint. pair $600.00; also Revox A-77 $395.00
plus shipping. (919) 449-4132.
AUDIO RESEARCH SP3A-1, $500; Tympani 3-A speakers
with bass screens $1200; Dual 76 $700; Ampzilla with meters, factory wired, $600; EC -3A crossover $450. (919)
449-4132.
THE BOTTOM END, as reveiwed in the April Stereophile. A
new compact super bass speaker that retails for around
$200.00. A no -compromise performer with smooth response
Hz. Ideal for use with Magnaplanars, Quads, Dahlquist, ESS, or any system deficient in law bass, because of
room placement. BOTTOM END CROSSOVERS permit the use
of one woofer, no bi-amping, one amplifier does it all. Model
X1 for ail Magnaplanars, Model X2 for all others. Literature
and information available upon request, dealer inquiries in-
below 20
Harwood Heights,
II.
60656
PRODUCTS FOR THE DISCRIMINATING AUDIOPHILE:
high output models available), Thorens, Shure Tonearms, etc.;
Large selection of esoteric used equipment. SOUND ADVICE,
536 St to Road, Emmaus,
Fri., 6-9:30; Sat. 10-6.
Pa.
18049. Hours: Mon., Thurs.,
IMPROVE SIGNAL TO NOISE RATIO on tape equipment
by actually measuring any damaging magnetic residuals, then
really demagnetizing with the powerful, sine wave Han D-Mag. Professional Han -D -Kit $58.50 delivered USA on prepaid orders. Literature and Article reprint available. ANNISCO,
1103 N. Delaware, Indianapolis, Ind. 48202. Phone (317)
637-9282.
AUDIO BREAKTHROUGHS-Long Island's newest and finest state-of-the-art dealer, featuring these outstanding lines:
Yamaha (the V-FET Amp, CT -7000 Tuner, and NS1000M
Beryllium Speakers), Magneplanar, IMF, Paoli, KEF speakers
and drivers. Soundcraftsman, Linn Sondek, Oecia, Supex, B&
W, Harmon-Kardon Citation, Dahlquist Marantz Professional,
FML Technics, Dynaco, and more. Custom modifications and
relaxed listening facilities await you, 1681 Northern Blvd.,
Manhasset, New York 11030. (516) 627-7333.
IN STORE DEMONSTRATION and private appointment
showroom featuring natural high definition sound from Audio
Research, Magnepan, Fulton, Audionics,
Radford, ESS, RTR,
Quatre, Braun, Sony Corp., V-FET's, SME, Thorens, Stax, Supex, Grace, Soundcraftsmen, Burwen, Marantz, Transcriptors,
more... also custom sub -systems and electronics modifications from our highly qualified service department. AudioTronics, Ltd., E 120 Wellesley, Spokane, Wash. 99207.
and
(509-484-1300).
THREE BOZAK CONCERT GRAND Speakers. Marantz 108
tuner. New condition. Best offer takes all or part. V. Dufford,
922 Morton St., New Castle,
Pa.
16101.
13 IN. WOOFER-15hz. Res, excellent construction, buta) suspension -excellent in acoustic suspension/transmission line
cabinets. Foam Grills custom cut to size. Special midrange
domes. 212-462-0984
-
IMF STUDIO 3B speakers. Excellent condition. 6 months old
$700. Tony Pariso, 273 S. Roycroft, Cheektowaga, New
York 14225.
CURRENT AND RECOMMENDED:
SUPEX SMM5 moving magnet cartridge. Not the best but ex-
ceptionally smooth. Nothing can touch it for $50.
940 oil damped, uni -pivot tone arm. $149.
LUX 1500 stereo receiver. 75 per channel @ 8 ohms, less
than .05 THD 20-20000, capture ratio 1.3. We bother to
import it because we think it is the best. $800.
FIDELITY RESEARCH cartridge and transformer. The best
moving coil yet. Highly regarded even by resident Decca
freak. Great depth of image and detail. Also variety of prepreamps. Cart. $130, Torodial transformer $150.
GALE speaker. Very accurate British bookshelf. $385. each.
CAMBRIDGE AUDIO P70 and P140 integrated amplifiers
with torodial power supply and state of art preamp. $350
and $550. Also TL100 and TL200 transmission line
GRACE
speakers. $400 and $500 each.
vited. Consumers write for the name of your nearest dealer.
M&K Sound Inc., 8719 Wilshire Blvd.. Beverly Hills, Calif.
DECCA BRUSH. Over
90211.
DECCA CLEAN-UP. The ultimate dust bug. Same bristles as
PEAK POWER METERS -1/4w to 1000w Kit or assembled.
PEAK LEVEL METERS -for taping -eliminates overdrive.
VU METERS -pro :ssional Quality at low prices -connects
directly to tape recorder, with illumination. Send $1.00 for
catalog. RECORDING SYSTEM DESIGN CO., P.O. Box 297, Le-
brush, conductive shaft and grand wire. $15.
also: GAS Ampzilla, Dayton Wright, C/M Labs, Lux, Radford,
Yamaha, Sony, BGW, Audionics, Revox. FMI 80, Celestion,
vittown,
N.Y.
11756
SAE MK III CM POWER AMP, $710. SAE Mk 113 preamp
$625. owned one month. Rich Rinehart 106 W. Norwich,
Columbus, Ohio 43201. (614) 297-1753.
SCOTCH-TOK-MEMOREX-MAXELL
Blank tape. Low
prices. Free catalog. S&P Enterprises, Box 111, Itasca, Ill.
a
million conductive bristles eliminate
need for liquids and reduce static. $15.
IMF, Transcriptors, Technics, Fons, Connoisseur,
Dual 601, 901, Decca Export, Ortofon, ADC, Sennheiser,
ADS,
Beyer.
Shipped free anywhere in U.S. and Canada.
GREENWOOD SOUND, INC.
5331 S.W. Macadam
Portland, Ore. 97201
503-224-1776
the Water Tower at John's Landing
60143.
AUDIO AUGUST, 1975
99
www.americanradiohistory.com
RTR 400E electrostatic
speaker system. Brand new in
facto-
$210 each. SAE Mark IVCM power amp,
100 watts/channel with output meters, $395. (516) 7990611.
ry sealed cartons!
CASSETTE
LABELS:
Custom-Blank. CASSETTE
TARZAC, 638 Muskogee Avenue, Norfolk, Virginia
BOXES.
23509.
DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES
WAREHOUSE OF BETHESDA, P.O. BOX 34251, WEST BETHESDA MD. 20034.
TANDBERG 9200XD Dolbyized, 3 -speeds. Brand new, original carton and warranty. Lists for $1000. Equipment reviewer used only for testing. Sell for $600. Box A58-2, Audio.
-
Our referenced amplifier
SOUND ADVICE MAGAZINE
is better than yours! We compare every amplifier tested
against a piece of straight wire, and analyze in detail how it
sounds different. We also A -B amplifiers with blind listening
panels, using original master tapes. Square waves are photographed, clipping checked and bass described. Our first issue
compared amplifiers from Accuphase, Ampzilla, Audio Re-
search, Rezak, Crown, Dynaco, Epicure, ESS, Harmon Kardon
(12 and 16) Infinity (Class D), McIntosh (2300), Paoli, Phase
Quintessence, Sony (V-FET), and Yamaha
(FET). 17 Cartridges were also reviewed: ADC(XLM-II and
export), Denon
(V and
Super XLM-II), B&O, Decca
Grace,
Fidelity
Research,
OLi 07),
and
(OL103
Quatre,
SOUNDTRACKS/0C, JAll/PERSONALITY
NEWSLETTER! RTSA. 3700 S. Plaza Drive, Bldg
High quality at reasonable rates. Joseph Giovanelli, Audio -
Santa Ana, California 92704.
Tech
2819 Newkirk Ave., Brooklyn,
Laboratories,
N.Y.
9-7134.
CUSTOM TAPE DUPLICATION
8 track and cassette. We
specialize in small runs. CUSTOM AUDIO c/o Dick Walen,
4226 Robert
St., Red Wing. Minn.
55066.
sonable rates. Sound Advisory
-
West Bethesda, Maryland 20034.
SERVICE FOR YOUR COMPONENTS. Having trouble getting satisfactory service on your equipment? Write for details
on our guaranteed service. The Audiophile, 582 N. Frederick
Ave., Gaithersburg, Md. 20760.
new $195.
Wharfdale WS -2
speakers, VG, $83
Hartley 210 MSG speakers, pristine, $235.
SAE MK-IVB demo amplifier. $250. Trades accepted.
WANTED: Marantz, McIntosh, Futterman tubed equipment.
Michigan
48179.
South
Rockwood,
Audiocraft,
Pair
$70.00 postpaid
AMPRITE SPEAKERS SERVICE
655 Sixth Avenue, New York,
212-CH3-4812
N.Y.
10010
a
unique, non-
supported hi-fi club featuring interesting
monthly meetings about sound and the latest audio techniques. We invite all N.Y. area audiophiles to attend one of
profit, member
these
our guest.
sessions as
Details about meetings and
membership available. Write Box 5889 Grand Central P.O.;
N.Y.C.
10017. Call 212-722-2781.
ization, Dolby, DBX, and the new SX74 Cutting System by
Neumann. Special package prices on pure vinyl album and
single record production. 1000 45 RPM stereo singles
albums $436.00 including printed jackets. Write or call for brochure. A & R
Record Manufacturing Corp., 902 N. Industrial Blvd.. Dallas,
LP
Texas 75207. (214) 741-2027.
Guaranteed repair of damaged or inoperative cassette tapes
$3.00. Kassette Klinic, Box 214844, Sacramento, Ca.
or in person, find out the correct way. Also find out
where to
get the right business contacts. Write for this valuable and
256
S.
Robertson, Dept. 1558
SPEAKERS
ALTEC WARRANTY STATION
JAZZ RECORDS Current,
$10.50
each postpaid
SOLD @ AUCTION: COLLECTORS RECORDS, LP's: Jazz,
Soundtracks, Personalities, O.C.. Country (Western, Blues, Indicate list from: Ray Macknic. P.O. Box 7511, Van Nuys, Calif. 91406, U.S.A.
FREE
-
Giant 64 page auction Record Catalog. Songs &
Records International, Box 863A, Burbank, CA 91503.
OUR UNIQUE SERVICE OFFERS YOU THE WIDEST AND
MOST UNUSUAL SELECTION OF CLASSICAL RECORDFROM THE FOUR CORNERS
INGS
OF THE WORLD.
-
SEND $1.00 FOR SAMPLE MAILER. AUGUST ROJAS
CLASSICAL IMPORTS, 353-1/2 NORTH LA BREA
AVENUE, LOS ANGELES, CALIFORNIA 90036.
CASH FOR Mint Ips & prerecorded reel tapes. Records, Box
323, Hillburn, New York 10931.
Best offer under
$350
pr. Boschen,
7
Ravine, Tenafly, N.J. 07670. (201) 567-2684, evenings.
28806
N.C.
JBL SE460 power amplifier.
24354, Oakland, Calif. 94623.
RECORDS
SHOW ALBUMS- Rare Out of Print LP's. 52 page list
50c Broadway/Hollywood Recordings Georgetown. Conn.
06829.
Rare, Out of Print. Free lists. DEPT.
AU1, P.O. BOX 125, JAMAICA. N.Y. 11415.
INFINITY 2000A
Hughes Electronics Service
45 Ounn St., Asheville,
Mint only.
C.
Brello, Box
WE MUST HAVE YOUR USED
COMPONENTS
Premium Trade or Cash for:
-
45 RPM Original hits. Catalog 50c C&S Record
Sales. Box 197, Wampsville, N.Y. 13163.
WHILE YOU WERE LOOKING for out -of -print records, you
should've been looking for us. Discontinued, 216 N. Rose,
Burbank, California 91505.
Broadcasts, soundtracks.
A.
Lutsky,
Personalities
McIntosh tube (pre) amps & tuners, Marantz tube (pre) amps
7 tuners, Marantz 7(T), 15, 16 (B). Futterman H-3, J.B.L.
400, 500. 600 series electronics, J.B.L. Hartsfield, L-101,
Metrogon, Minigon, Music & Sound Ltd., 11'/2 Old York Rd.,
Willow Grove, Pa. 19090. (215) 659-9251.
WANTED: NEW OR USED ALTEC Barcelona, JBL L101,
Olympus, McIntosh C22, C28. Mr. Kazuhiko Murata, 1-67203, Tsurumaihigashi, Nara City, Japan.
of
Thirties, Forties. Box 225, New York, N.Y. 10028
WANT TO BUY any used CB equipment. Will pay up to
75% of original price. Call (213) 429-0746 collect, if neces-
SOUNDTRACKS
sary.
-
JAZZ
Long Island City, N.Y. 11105.
-
POP. Vincent, Box 5202,
TAGE SOCIETY, Box
932 AU, New York,
I
N.Y.
10023.
2862 Heather, Long
write to Audio Box A56-3.
Roberta Hanra,
90815.
Renaissance, Baroque, Classical, Romantic, Modern Music.
Not sold in stores. Not listed in Schwann's. Highest quality!
Budget label prices! Available only by mail. MUSICAL HERI-
100
etc.
WANTED
Jackson Audio Generator model 655. Robert
Bezak, 303 Mapeat Lane, New Castle, Pa. 16101.
MUSICAL SPEAKERS REPAIRED
FREE 200 -PAGE CATALOG. 1,400 New Stereo Recordings.
469 Chestnut St., NASHVILLE TENNESSEE
d'Antibes,
in lots of 10. Send check or money order
USED QUAD ELECTROSTATIC SPEAKERS wanted. Any
condition. Describe units and state bottom price. Apt. 2202,
1360 Lake Shore Drive, Chicago, IL 60610.
Beverly Hills, Ca. 90211
PRESS HIGH
37210.
rue
St., San Francisco, Calif.
QUALITY PURE VINYL RECORDS FROM YOUR TAPES. SEND
SAMPLE RECORD AND PRICE LIST. ALSO FINEST DISC
Le
MARANTZ 7C, 9: McIntosh C22. John Fang, 1238 Green
94109.
informative booklet. Send $3.00 to:
CATALOGS.
MASTERING.
Dans
EQUIPMENT WANTED
Maher, 5 Evans Place, Orinda, Calif. 94563.
FOR
-
Big Bear Stomp. OrienCity Jazz Band
-i -a Blues My Naughty Sweeties Gives to
residents add 3 sales tax Dealers wanted.
Burwen Laboratories Inc. 209 Middlesex Turnpike. Burlington, Massachusetts 01803 617-273-1488.
SONGWRITERS
Present your songs to publishers like professionals. By mail
FILM -STAGE SOUNDTRACKS. Large free list.
P.O. Box 835, Sequel, Calif. 95073.
NASHVILLE RECORD PRODUCTIONS WILL
Me.
95821.
TAPE RECORDER HEADS brought back to spec. Wear removed. Brilliant finish. $10.00 each. One day service. E.
DON'T PAY the high mail order prices. Thieves Warehouse
is coming to your area. Franchises available. Thieves Warehouse, P.O. Box 8057, Pensacola, Florida 32505.
496
93545
Massachusetts
THE NEW YORK AUDIO SOCIETY INC. is
OLDIES
HIGH FIDELITY SPEAKERS REPAIRED
P.O. BOX
98114.
SUNSOUND
SERVICES
5th Ave.,
LONE PINE, CALIF.
BL -2. The East Bay
(313) 379-9945.
AN IMPORTANT ANNOUNCEMENT
Parnassus Audio is now producing a fuN Class A
(not AB) stereo power amplifier capable of relatively
high output power.
The amplifier additionally satisfies the theoretical
criteria' for completely eliminating transient intermodulation
distortion.
The difference in sound quality between this amplifier
and conventional amplifiers is easily audible, even to the
inexperienced.
We welcome requests for a descriptive brochure.
Dealerships will be limited.
PARNASSUS
AUDIO,
inquiries to:
all
Address
2918 Harper Street, Berkeley, California.
-
SURPLUS RECORD & TAPES
tal Strut. Louis -i -an
pair. Sony TC -350 tapedeck, mint, $155. Sheffield recordings.
sold. Junker, 705
100 STEREO LP'S Factory Fresh, all Major Labels, all Brand
New. $65.00 per 100.
source to Maxell UD tapes & cassettes at amazingly low
prices. DBX. Dolby available. Box 3065, Seattle, Washington
$273.00 including mastering. 100
lifier,
-
PERFECTLY CLEAR"' ultra hi-fi record Burwen Laboratories
94108.
TransLOUDSPEAKERS.
GLASCONE
electronics. Leak
Mark Levinson
criptors
turntables.
English tubed FM -Tuners. C/M Laboratories electronics/
speakers. Burwen noise reducers. Jensen Fives speakers,
mint, $290 pair. Beam -Echo mono tubed English amp-
CLASSICAL LPs bought
94118.
San Francisco, Ca.
ULTIMATE DUPLICATION (10 up) from your program
STEREO MASTERS, RECORDS AND ALBUMS. Check our
prices. Newest type high level cutting equipment featuring:
Neumann VMS 70 Computer control lathe, Parametric Equal-
SHOT -GLASS
QUADRAPHONIC RECORDS AND TAPES - World's largest selection - all labels, over 1000 titles - at discount
prices! For your free illustrated quad catalog, write: SOUND
CONCEPTS, 2713 West Radon, Dept. C8, Peoria. Illinois
61604.
rea-
34045,
Service, P.O. Box
FREE
F/211,
IN
(900,
Supex
Micro -Acoustics, Ortolan,
Satin, Stax,
and
900 prototype) and Win Lab. In addi901
tion to frequency and square wave response, we described
how each sounded in six crucial characteristics. There's much
4 issues for $9.00 ($12.50 foreign). SOUND ADmore
VICE, 225 Kearny, No. 202C, San Francisco, California
-
--
CUSTOM RECORDING SERVICE, Tape and disc. Stereo
and mono. Live and copies. Editing, Masters and pressings.
AUDIOPHILES! Your technical questions answered
DON'T PAY THE HIGH MAIL ORDER PRICES. THIEVES
WAREHOUSE OF MOBILE, 1770 BELTLINE HIGHWAY, MOBILE, ALABAMA 36609.
Linear,
RECORDS
SERVICES
FOR SALE
Or
Beach, Calif.
WANTED -Pioneer SX-1010 & SA -9100; ESS-AMT series;
Garrard Zero 100 SB or 100C; Sony & Tascam tape equipment; cartridges new or top condition only. Send specs, lists
& prices
to: Louis
Smiler, 139 Dawes Road, Toronto. Ont.
M4L 501.
AUDIO
AUGUST, 1975
AUTO
ACCESSORIES
EQUIPMENT WANTED
WANTED: RECORDING HEAD for KLH-41 Dolby open reel
deck. New or near new perfect. KLH ignoring year old order.
4600 Lamont,
J.R. Cavanaugh,
San Diego.
(714) 274-5074
AUTHORS, BOOKS
SANDBLASTERS - $39.50-$839.50. Free Catalog. Truman,
1330A Market, Youngstown, Ohio 44507.
PUBLISH your book! Join our successful authors: All subjects invited. Send for free appraisal and detailed booklet.
Carlton Press (Dept. VRT) 84 Fifth Avenue, New York 10011
(eve.).
ha, Neb.
68106.
WANTED: STAX CAPACITOR Pickup model CPX. J.P. Sam rout, 432 Chestnut Ave., San Bruno, Calif. 94066.
WANTED: JBL SG -520, SE -400S. SE -460, Mr. Kazuo Takishima, 33-7-1421, Takashima-Daira 2-chome, Itabashi-ku,
Tokyo, 175 Japan
WANTED: Marantz 7C (tube), 9S (pair), model 500. K. Takishima, 33-7-1421, Takashima-Daira 2-chome, Itabashi-ku,
Tokyo 175, Japan.
NAKAMICHI 700, used and in good condition, with 20dB
meters. (312) 748-7837 after 6 P.M.
PHOTOGRAPHY
RADIO PROGRAMS
ELECTRO -VOICE PATRICIAN IV complete 4-way speaker
systems. State condition, price. Don Cohen, Box 6281, Oma-
1930-1962 RADIO PROGRAMS, Reels. $1.00 hour! Cassettes, $2.00 hour! Mammoth catalog $1.25. AM TREASURES, Box 192M, Babylon, New York 11702.
RENT RADIO SHOWS - Make your own copies or just listen. Great way to build your collection reasonably. Catalog
$1 refundable. OTR Rental, Box 465, Livermore, Ca. 94550
YESTERDAY'S RADIO PROGRAMS ON TAPE. Reels, cassettes - fast reliable service. Catalog $1.00 refundable with
first order. ADVENTURES, 1301-A North Park Avenue, Inglewood, California 90302.
RENT OLD RADIO PROGRAMS as low as 50c per reel
P.O. Radio
RENT Open Reel or Cassette Prerecorded tape. All labels.
Catalog $1.00. Tape & Time, P.O. Box 740, Hopkins, Minn.
55343.
EVERYTHING
ON
OPEN
REEL!
Prerecorded
classi-
cal/popular tapes. Latest releases. Dolby Quad, 96 -page catalogue $1. Barclay -Crocker, Room 857A. 11 Broadway, NYC
10004.
HAWAIIAN MUSIC
on reel, cartridge, or cassette. Great for
entertainment, or music collection. Send 25c for catalogue;
refunded on order. Free gift included. Kamele 0 Hawaii. P.O.
Box 1312, Kaneohe, Hawaii 96744.
AMBIPHON'S RECORDS AND TAPES
HEAR POLICE FIRE Dispatchers. Catalogs show receivers:
exclusive directories of "confidential" channels. Send toc
stamp. Communications,
Box
56AU, Commack, New York
11725.
HIGH FIDELITY
DYNAKITS, IAD, lowest prices, Underground HI-FI Sales,
324 Broadwater Road, Arnold, Md. 21012. (301) 647-0919.
AURATONE,
92014.
UP TO 60% DISCOUNT. Name brand instruments. Catalog.
Freeport Music. 455R Route 110, Melville, N.Y. 11746.
GOLDEN AGE RADIO -your best source for radio tapes.
Box 25215-0. Portland. Oregon 97225.
40% DISCOUNTS. Huge Stock of Name Brand Instruments.
Free Catalog. Gratin's 110 Dept. A. 606 Route 110. Hunt-
Box 4305B, Washington. D.C.
20012.
SCOTCH, CAPITOL. Blank cassettes, cartridges, reels. Discount prices. Lawson's, Box 510, Livermore, CA 94550
Nostalgic Radio, Box 29K, Peoria,
II.
BUSINESS
OPPORTUNITIES
61601.
HELP WANTED
500/THOUSAND, stuffing envelopes.
EMPLOYMENT INFORMATION
Electronic Technicians
How to earn $17,000-$22,000 yearly, $350-550 weekly.
Not field service. Not overseas. No degree necessary. Work in
U.S.A. Details $3.00. WENDEL L. DANIELS, CONTRACT ENGINEERING, 8450 Anthony Wayne Ave., Cincinnati, Ohio
AGENT FOR U.S.A. wanted for our products: 3 -way low
coloration horn systems (also 2 & 4 -way systems); world's
only power amp with perfect square -wave response into capacitive load; battery powered pre -amp with world's lowest
noise figures; and lots of other equipment with optimum
transient response. Special Audio International, S-58221
Linkoping, Sweden. Tel. 013/113873.
BOOKS
FREE
LIST
Circuits. Increase technical competence. Complete and guaranteed course is highly effective. S10.00. Free literature.
DYNASIGN. Box 60AM, Wayland. Mass. 01778.
N.
Rockwell, Oklahoma City,
OK
73127.
UNIVERSITY DEGREES
BY
TRACK STEREO TAPES Factory Fresh, all Major La-
$100.00 per 60. 40 Cassettes Factory
Fresh, all Major Labels, all Brand New, $68.00 per 40.
bels, All Brand New,
SURPLUS RECORD & TAPES
P.O.
496
CALIF. 93545
BOX
LONG PINE.
SCOTCH AND MAXELL TAPE discounted. Write and save.
N.A.B. Audio, Box 7, Ottawa, III. 61350.
COMPLETE Stock of 8 track tapes, prerecorded and blank.
New collection of classical recordings on 8 track tapes. Stereo equipment and accessories. Discount prices on all merchandise. Free Catalog. Victory Tape Sales, 2646 N.E. 189th
Terrace, Miami, Fla. 33160.
LOW COST POPULAR BOOKS. SUCCESS,
OF
HAPPINESS, PERSONALITY, wealth, personal problems. Capital Products. Box 1119, Dept. F. Langley Park, MD. 20787.
BOOKS....FREE
CATALOG.... Books that
are
exciting,
unique, and very unusual, such as self-improvement, sex,
moneymaking, sports, witchcraft, astrology, numerology, hypnosis, and many, many more. Write Plaquemines Distributors,
Dept. 5 -AA. Rt. 2, Box 304. Port Sulphur, La. 70083.
INSTRUCTION &
EDUCATION
EARN B.A. Theology. 1425
Free supplies. Plus a
list of 50 firms wanting homeworkers, addressers and mailers. Send self-addressed envelope to: Kevin Heinrich, P.O.
Box 122, Hayes Center, Neb. 69032.
45216.
MAIL. Bachelors, Masters,
1425 -AM, Tus-
PhD. Free Revealing details: Counseling, Box
tin, California 92680.
AUDIO
ington. N.Y. 11746.
OLD RADIO PROGRAMS ON TAPE. Thousands available.
Low prices, finest quality, immediate service. Catalogue 25c.
AUDIO DEALER
PRODUCTS
DIGITAL ELECTRONICS! Design and understand Digital
SCOTCH RECORDING TAPE, lowest prices TAPE CENTER
8
MUSICAL
INSTRUMENTS
50c. 30 minute sample tape with catalogue $1.25. Satellite
Broadcasting, Box 512, Miami. Florida 33165.
DISCOUNTS, FREE SPECIFICATIONS,
BOX 580-22, DEL MAR, CALIFORNIA
TAPE &
TAPE RECORDERS
60
547 -AM, Pennsboro, WV 26415.
OLD RADIO PROGRAMS on tape and cassette. Catalogues
NOW AVAILABLE ... FAMOUS REFLECTING SYSTEM'S
41/2" REPLACEMENT DRIVERS. $7.98 POSTPAID. BIG
QUANTITY
BUGGED? Don't be Watergated! Counter-
measures brochure $1.00. NEG-EYE LABORATORIES, Box
OLD TIME RADIO PROGRAMS on cassette. Catalog $1.00.
MB/JB Enterprises. Box 724. Spencer, Iowa 51301.
eo.
SHORTWAVE
TELEPHONE
Lone Pine, Calif. 93545
-
Quad and sterHighest quality available anywhere! Send stamped, addressed envelope to: Amhiphon Records, Dept. A, P.O. Box
341, Kingsbridge Station, Bronx, New York 10463.
PLANS & KITS
synthesizer concept -features universal compatibility,
modular construction. For complete information send SASE
or 25c to: CFR ASSOCIATES, POB F, Newton, NH 03858
YESTERYEAR RADIO
Faulkner, 24 School Street, Keene, N.H.
TAPE RECORDINGS
-
--
-
8MM
16MM
Super -8
Art & Film GraphSlides, Catalog & Sample 35 cents
ics. Box 17598, San Diego, Calif. 92117.
PROFESSIONAL TITLES
EM
week.
HERESY, CORNWALL, JBL, Klipschorn, Bose 901. Bruce
PHOTO BUTTONS made from your photograph or any slogan, advertising, picture, etc. Only $1.25 postpaid. Arcan
Products, Rt. 1, Box 278. Waldorf. Md. 20601.
AT LAST! DEPENDABLE, LOW COST Component Switching Devices for A -B comparison of speakers, amplifiers, and
B.A. Kunz
tape decks. Write for information and prices to
Electronic Equipment, 12111 La Padera, St. Louis, Mo.
-
63033.
SITUATION WANTED
-
high school and Recording Institute of
seeking job training in the Audio and
Recording field. Mike Dooley, 14338 Lyons, Livonia, Mich-
YOUNG MAN
PROFESSIONAL HI-FI COURSE -Instructors include Len
Feldman, Julian Hirsch, Larry Klein, and Larry Zide. Home
study course also available. Send $1.00 for audio primer and
full information or visit HI-FI EXPO, 393 5th Ave., New York
City 10016.
America graduate,
THE AUDIO WORKSHOP
Comprehensive practical training in SOUND RECORDING,
PRODUCTION, and REINFORCEMENT. 16 -track facilities for
endorsed license, 2 years college, 2 years experience. Contact: Doug Galliher, 3907 Angol Place, Jacksonville. Florida
igan 48154. (313) 427-7835.
FORMER DJ would like to return to radio in a similar posihave a third class broadcast
tion or as a Program Director.
I
projects. No prerequisites. Accommodations available. 50 Union Park, Boston, MA 02118 (617) 266-7561.
student
OHM'S LAW slide rule $1. Norvex
folk, VA 23513.
Co.,
3920 Larkin, Nor-
32210.(904)771-7386.
EXPERIENCED AUDIOPHILE AVAILABLE! Young, hardworking individual seeks employment with Audio firm. Degrees, electrical engineering technology. Much experience retail and merchandising. Reply Box A58-3 c/o Audio.
101
AUGUST, 1975
www.americanradiohistory.com
"The Sony TC -756 set new records
SONY
irPF
P
ii
MAN ,ti
TC -756-2 Stereo
Deck also features 15 and
7% ips tape speeds; Ferrite & Ferrite
2-track/2-channel stereo three -head configuration;
symphase recording that allows you to record FM matrix or SQ''1
4 -channel sources for playback through a decoder-equipped
4 -channel amplifier with virtually non-existent phase
differences between channels. Also available, TC -756
with quarter-track/2-channel stereo head configuration.
www.americanradiohistory.com
for performance of home tape decks:'
(Stereo Review, February, 1975)
Hirsch -Houck Laboratories further noted, "The
dynamic range, distortion, flutter and frequency response performance are so far beyond the limitations
of conventional program material that its virtues can
hardly be appreciated:'
The frequency response of the TC -756-2 is rated
at 30 to 30K ± 3 dB at 15 ips. Hirsch -Houck Laboratories said, "Although no claims are made for the
TC -756-2 in this regard, it is the first machine we
have seen whose frequency response should allow it
to copy CD-4 discs in their encoded form"
The Sony TC -756-2 is representative of the prestigious Sony 700 Series -the five best three -motor
10% -inch reel home tape decks that Sony has ever
engineered.
Like the TC -756-2, all feature a closed loop dual
capstan tape drive system that reduces wow and flutter
to a minimum of 0.03%; logic controlled transport functions that permit the feather -touch control buttons to
be operated in any sequence, at any time without spill -
ing or damaging tape; an AC servo control capstan
motor and an eight-pole induction motor for each of the
two reels; a record equalization selector switch for
maximum record and playback characteristics with
either normal or special tapes; mic attenuators that
eliminate distortion caused by overdriving the microphone pre -amplifier stage when using sensitive condenser mics; tape/source monitoring switches that
allow instantaneous comparison of program source to
the actual recording; a mechanical memory capability
that allows the machine to turn itself on and off automatically for unattended recording; and a full twoyear guarantee'`
In addition, each deck has its own versatile combination of built-in professional functions.
Sony engineers know that it's not one featurebut a combination of high performance features that
makes a good unit great. Sony knows. Stereo Review
knows. If you're a serious recordist, you'll want to know
more about the Sony 700 Series.
SONY®
Brought to you by
TC -755 Stereo Deck also offers
the lowest price in the Sony
700 Series at $699.95; Ferrite
&
Ferrite heads; symphase
recording; 7% and 3% ips tape
speeds; tape path adjuster for
even tape winding.
SUPERSCOPE.
TC -758 Automatic Reverse Stereo
Deck adds features like programmable
auto reverse and bi-directional recordingthat allow up to 6 hours continuous
record and playback time-longer
than any Sony unit; roto -bilateral
Ferrite & Ferrite heads that offer wider
frequence response, better tape -to head contact and less distortion than
other magnetic heads; sym phase recording; and 7% and 3% ips tape speeds.
TC -788-4 Quadradial Deck features 4 -
channel record and playback; built-in
that function as a built-in
mixer; synchro-trak that allows record
heads to double as playback heads for
PAN POTS
perfectly synchronized multi -track
(sound -with -sound) recording;
mode selector switches that make it
virtually impossible to erase mas-
ter track while recording additional
tracks; and 15 and 7% ips tape speeds.
'Superscope, Inc. guarantees to the original registered owner that all parts will be free from operating defects for two years from purchase date. Product will be repaired or replaced
free of charge in the sole discretion of Superscope, Inc., provided it wasurchased in the U.S.A. from an authorized dealer. The serial number cannot be altered or removed. Product
must be serviced by authorized Superscope repair technicians only. **'"CBS, Inc. © 1975 Superscope, Inc., 8150 Vineland Ave., Sun Valley, CA 91352. Prices and models subject to
change without notice. Consult the Yellow Pages for your nearest Superscope dealer. Send for free catalog.
www.americanradiohistory.com
If you listen to the experts,
you'll listen to our speakers.
Ask any audio expert what makes a speaker
good. If he's Stereo Review's Technical Editor,
Larry Klein, he'll tell you, "A speaker should
have no character or sound quality of its own
... a speaker should be neutral." Or ask Julian
Hirsch:
uncolored sound is the only kind
of speaker response that gives the listener
a good chance of hearing a balanced sound."
If you listen to the experts, you'll took for
neutrality in speakers. That's why you should
listen to the T-200, Technics' 2 -way speaker
system. Hirsch -Houck Labs did: "... highs were
virtually perfect ... response of the woofer was
notably smooth ... difficult to believe that the
sound is coming from an inexpensive compact
system." Popular Science rated the T-200
"excellent ... good tonal balance ... very clean,
accurate sound."
The experts are even more impressed with
the T-400, Technics' 4 -way speaker system.
H1gñ Fidelity: "... the sound produced is well
.
-
balanced ... neutral and uncolored with very
good internal separation on complex
instrumental textures ... easily one of the better
non -compact.speaker systems.' Martin Cifford
of FM Guide: "-Having a pair of super -tweeters
angled to disperse sound ...means not worrying
about the directionality of the highs ... bass
response was good and clean."
For the complete reviews and other technical
information, write: Mr. lack Bloom, Panasonic,
1 Panasonic Way, Secaucus, N.1. 07094.
Technics also offers you the T-300 and T-500.
The reviews aren't in yet, but since they share
the neutrality and other important
characteristics of the T-200 and T-400, we expect.
the experts to be equally enthusiastic.
The concept simple. The execution is
precise. The performance is outstanding. The
name is Technics.
FOR YOUR TECHNICS DEALER, CALL FREE 800 447-4700.
IN ILLINOIS, 800 322-4400.
Technics
by Panasonic
check Vo.
3' on Reader Se vice Cad
--300
-s0t
¡
1_.
79-
,--
www.americanradiohistory.com
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