IItCOFIWIING - American Radio History
VOL. 2 NO. 9
SEPT. 1977
MoMN
IItCOFIWIING
SERVING TODAY'S MUSIC/RECORDING-CONSCIOUS SOCIETY
imeow
OyuWr 'NII
v
From Tape to
-Disc Maste
Fathoming the
Lab
N
$1.50
#06691
444-
You know what to expect from
brick walls, low ceilings and
hard floors. Your bass gets
eaten by the drapes and our
guitar solo echoes right back
at you. The environment of a
small club is designed to make
it a good place to drink and
dance, not necessarily a good
place to perform. What you
need is the ability to tailor
your sound to the room.
bilitr enables the Six -band
\
%
v
At MXR, we realize that q Jality sound is essential to
a musician, wherever he plays. MXR Graphic Equalizers can give you the control to make that sound,
your sound, possible, whather you are playing in a
small club, in a large audi-orium, or any place
in- between.
Available in either Six or Ten -band ranges, MXR
Graphic Equalizers are designed to precisely modify
selected frequency ranges in order to compensate
for aural discrepancies caused by the acoustical
environment.
MXR's Six -band Graphic Equalizer has been designed
for modification over the tonal response range (100
Hz -3.2 KHz) and is ideal for use with electric and
acoustic guitar, bass and brass. Its overdrive capa-
Graphic Equalizer to selectively distort at any given frequency. The MXR Six -band Graphic
Equalizer is battery powered
with battery life of up to one
year in normal use.
\
The Ten -band Graphic Equalizer expands the capability of
sound control even farther. Ten
bands cover the entire frequency spectrum in octave increments that allow you to specifically boost or diminish
the tonality of any part of your performance. Its frequency range (31.2 Hz- 16KHz) is sufficient to allow
the widest range of application, including; musical
instruments such as keyboard and drums as well as
PA mains and /or monitor equalization. The MXR
Ten -band Graphic Equalizer is AC powered, can
handle both low and high impedance signals and
is extremely quiet.
Both the Six and Ten -banc Equalizers are ruggedly
constructed for long -term reliability. So, now you
can make any environmen- a controlled environment
with an MXR Graphic Equalizer. To hear the difference
for yourself, see your MXR dealer. MXR Innovations,
Inc., 277 N. Goodman St., Rochester, N.Y. 14607.
t
iQiebbi+li(
Products Group
CIRCLE 56 ON READER SERVICE CARD
Our new AD
cassette
takes the
Horntal bias
extremes.
We made a name for ourselves by creating
the world's first non-chrome, "high" (CR02)
bias /EQ cassette tape, TDK
Super Avilyn (SA). The state -ofthe -art tape that has quickly
become the standard of reference
for cassette tape performance.
Our latest innovation is called
AD (ay-dee), and we predict it
will soon become the standard of
performance and economy in the
"normal" bias /EQ position.
We produced the first high
fidelity ferric oxide cassette tape
some ten years ago, and we've
been perfecting the formulation ever
since. Our new AD delivers superior
performance, especially at the critical
high-frequency range (7kHz to
20kHz), where many mid -priced
cassette decks and even premiumpriced cassettes tend to fall off too
quickly.
AD is our ultimate ferric oxide
tape designed for the "normal" bias/EQ
position. Overall, it provides the
lowest noise, highest frequency
response and widest dynamic range of
any pure ferric oxide cassette tape. In 45,
60, 90 and 120 minute lengths, AD has the
same super -precision cassette mechanism
found in TDK SA, in a new blue-gray shell.
And AD brings its audible benefits to
all cassette decks, with and without switch able bias/EQ, including those found in cars,
portables and home stereo systems.
So the music you love can travel with you,
with all of the clear, crisp, brilliant sounds
that make music so enjoyable.
AD is the forest pure ferric oxide
cassette tape you can buy at any price.
And it has TDK's full life time warranty.
Give our new high -fidelity, moderatelypriced AD a try -it's anything but normal.
TDK Electronics Corp., 755 Eastgate
Boulevard, Garden City, New York 11530.
In Canada: Superior Electronics
Industries, Ltd.
&TDK
The machine for your machine.
CIRCLE 79 ON READER SERVICE CARD
Stones' Rolling Studio
a van? For Mick Jagger, it is almost a necessity. Mick and the Stones can be inspired to produce their next hit anytime,
but when they're on tour or on vacation, the best recording studios aren't
always around the corner. The Stones rely on their Shure -equipped mobile
studio for the unmatched recording perfection they insist upon for these
moments of midnight inspiration. Whether in a recording session or on stage,
the Stones' SM7, SM58, SM82, SM53 and SM56 microphones are their
assurance of consistent quality and natural sound.
A complete recording studio in
Shure Brothers Inc.
222 Hartrey Ave., Evanston, IL 60204
In
Canada: A. C. Simmonds & Sons Limited
FI
SHIJR
o
Manufacturers of high fidelity components, microphones, sound systems and related circuitry.
CIRCLE 34 ON READER SERVICE CARD
SEPTEMBER 1977
o DON
VOL. 2 NO. 9
RiCo RDIING
SERVING TODAY'S MUSIC /RECORDING - CONSCIOUS SOCIETY
THE FEATURES
THE STAPLES
FATHOMING THE DEPTHS
OF THE SPECS
29
Dick Rosmini
Specifications. They were originally intended to help us compare and evaluate
quality and performance, but let's face
confusion reigns. Find out how knowing your specs can help you to create better
recordings.
it-
A SESSION WITH BLUE OYSTER CULT
By Veda Neu Solomon
36
How do three producers, an engineer who
"produces his end" and five band members
who have extremely diverse writing styles
manage to stay together long enough to
record six previous albums? Author Solomon
sits in on the new Blue Oyster Cult album
and describes the sessions.
FROM TAPE TO DISC
-DISC MASTERING, Part
2
44
By David Moyssiadis
Mastering engineer Moyssiadis continues
with his views and explanations of the disc
mastering field. In this final part we learn
what we can do to make the mastering process easier for all involved, and how to insure
ourselves of a quality disc.
COMING NEXT ISSUE!
Chicago "Live"
Sound Reinforcement at Newport
Profile: Producer/engineer Roy
Halee
Modern Recording is published monthly by Cowan Publishing Corp., 14
Vanderventer Ave., Port Washington, N.Y. 11050. Design and contents are
copyright by Cowan Publishing Corp. and must not be reproduced in any
manner except by permission of the publisher. Second class postage
paid at Port Washington, New York, and at additional mailing offices.
Subscription rates: $12.00 for 12 issues; $22.00 for 24 issues. Add $3.00
per year for subscriptions outside of U.S. Subscriptions must be paid in
American currency.
LETTERS TO THE EDITOR
4
TALKBACK
The technical Q & A scene.
THE PRODUCT SCENE
By Norman Eisenberg
The notable and the new, with a comment
on direct -to -disc recording.
22
MUSICAL NEWSICALS
By Fred Ridder
New products for the musician.
26
AMBIENT SOUND
54
By Len Feldman
Reviewing one of our constant but very often
confusing audio companions -impedance.
LAB REPORT
By Norman Eisenberg
and Len Feldman
BGW 500D Power Amplifier
H.H. Electronic Echo Unit
Teac A -650 Cassette Tape Recorder
HANDS -ON REPORT
By Jim Ford
and Brian Roth
Uni -Sync Trouper Series Ill
GROOVE VIEWS
58
66
70
Reviews of albums by the Earl Scruggs
Revue, Symphonic Slam, Kursaal Flyers,
Genesis, Ornette Coleman, George Duke and
Anthony Braxton.
ADVERTISER'S INDEX
80
Cover photo © 1977 Lynn Goldsmith
3
/MODERN
ILITE ':3
RIMING
SERVING
TODAY'S MUSIC /RECOROING-CO
SOCIETY
\NSCIOUS
/-1,-Ar7
40
Leb0I0G4
H.G. La TORRE
Editor
ROBERT ANGUS
NORMAN EISENBERG
LEONARD FELDMAN
Audio Editorial Board
FRED RIDDER
JIM FORD
BRIAN ROTH
NAT HENTOFF
Contributing Editors
STEFFON A. KACHOCKI
Production Manager
MELANIE DEUTSCH
Production Assistant
RICHARD FERTELL
continues.
Advertising Director
Again, I would like to commend you on an excellent publication, and look forward to reading more articles by Mr. Feldman,
and more on TIM, possibly with some sort of reference to it in
future equipment test reports.
-Michael Morrow
Little Rock, Ar.
BILL SLAPIN & CO.
West Coast
Advertising Representative
BILL TRAVIS
Art Director
SHERYL STERN
LIZ BEENER
HAROLD PERRY
Art Staff
VINCENT P. TESTA
Publisher
Editorial and Executive Offices
Modern Recording
14 Vanderventer Ave.
Port Washington, N.Y. 11050
516-883-5705
COWAN PUBLISHING CORP.
Chairman of the Board Sanford R. Cowan
President Richard A. Cowan
Controller Cary L. Cowan
Editorial contributions should be addressed to
The Editor, Modern Recording, 14 Vanderventer
Ave., Port Washington, N.Y. 11050. Unsolicited
manuscripts will be treated with care and must be
accompanied by return postage.
4
TIM Pleases Reader
The July, 1977, issue of Modern Recording was the first copy I've
had the pleasure of reading. The magazine seems to be filling the
pro/am gap by providing basically informative as well as moderately technical articles.
I was extremely pleased with Mr. Feldman's article on "Otala"
distortion or TIM (transient intermodulation distortion) (Ambient Sound, page 66).
As Mr. Feldman points out, the industry hasn't yet set up a criteria for quantifying TIM, but it is possible to "graphically and
visually detect the presence or absence of TIM" and make direct
comparisons between different amplifiers.
Paul Klipsch, of Klipsch and Associates, has begun to do just
that, and some of his initial findings are quite interesting (though
his research is moving a little slowly since it's one of his "nonprofit" activities).
So far the "top" two amplifiers (those exhibiting the lowest
TIM) are the BGW 100 (solid state) and the Marantz Model 7
(tube type) while the two at the other end of the spectrum were
also transistor and tube. The battle between tube and transistor
Impedance Confusion Remains
Mr. Blakely's answer to Stephen Kayser's query on impedance
(Talkback, June, 1977, p. 13) is typical of the confusion that still
remains, both in and outside of the industry. While there is no
one rule that defines every situation, to say that "any output is
happy feeding any input that is the same impedance. .." is in
many situations quite incorrect and often results in gross distortion.
Admittedly, I am not familiar with the output circuitry of the
dbx 154, and perhaps Mr. Blakely's reply is correct with regards
to that specific product. But many products utilize transformerless output circuits such as emitter followers, voltage followers,
etc., whose tolerance to loading varies with the particular design.
While most of these circuits provide a low impedance source,
many of them will not drive an equivalent load without an
increase in distortion or a decrease in output level, or both. This
type of output circuit is intended, typically, to feed a high impedance input (10K ohms and up).
Where matching impedances are required, one typically finds
output transformers utilized which transfer signal power rather
than voltage, e.g., 600 -ohm studio lines. These, too, may feed
high impedance inputs, but usually require a load resistor so that
the transformer is properly terminated.
I have little doubt that Mr. Kayser's equipment is satisfactorily
compatible; my concern is for other unwary readers who may
conclude from Mr. Blakely's reply that they can now, for example, connect their "semi-pro" or hi -fi deck into a 600 -ohm line
MODERN RECORDING
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For further information and our free catalog write to
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CIRCLE
51
ON READER SERVICE CARD
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input, or "Y" the outputs on a similar
device, with no penalty.
-Arne
Berg
Consultant
La Puente, Ca.
A
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CARVIN features the
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eliminating retail
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CARVIN offers TUBE & Solid -State
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CARVIN
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Congratulations! Going monthly is a
fantastic decision. So I want to thank
you all for this, and the valuable information in each issue.
Also I want to thank Mr. Eisenberg
and Mr. Feldman for the "Lab Report"
column. It's always good to have someone else spend time testing equipment
and devices and figure out accurately
its pluses and drawbacks. I have a suggestion to make. I would like to read an
article about techniques in mix- mastering and disc -mastering. I'm sure that
plenty of readers will love it.
And finally a simple question. What
does "A & R" stand for?
-J.M. Anzaldua
Mexico 18, D.F., Mexico
Articles on mastering procedures will be
forthcoming in Modern Recording. "A
& R" stands for "Artist and Repertory."
Channels with Bal. Inputs, 10 Band
Graphic Equalization, Bi -Amp Crossover
Networks, Stereo Panning, plus more.
CARVIN'S Professional Club and Commercial sound -reinforcement systems
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Factory Direct Prices
Name
An Order from Austria
In a TAPCO manual, I found your address. I'm interested in the book, Modem Recording Techniques by Robert
Runstein published by Howard W. Sams
Co. and a few newer issues of Modern
Recording. Please tell me their prices
and the cost to send it to me. I could
order a bank to do it for me and I could
inform my friend Mr. Cernohouse the
same way.
-Michael Tomoff and
Christian Cernohouse
Wien, Austria
For back issues of MR, simply write
to our Subscription Department and
order them at $1.75 per copy plus
$1.20 for postage to Austria. Current
issues are available by subscribing and
including a $3.00 mailing charge for
overseas delivery. The book Modem
Recording Techniques by Robert Run stein is available for $9.95 plus postage
from Howard Sams Co., 4300 West 62nd
Street, Indianapolis, Indiana 46268.
Please pass this information along to
your friend, Mr. Cernohouse.
trade magazines and such, I usually end
up like I just tried to decode the Dead
Sea Scrolls. However, along comes
Modern Recording giving me that which
I want to know in layman language.
Right on, fellas!
One of those items of invaluable info
which was of immense aid to me and I'm
sure to others was your "P.A. Primer"
series. It was what I needed and loved it.
But... I missed the first part. What I
need is to get a copy of that article...
better yet the whole magazine for that
matter. If you could send it to me or a
copy of the article, or how I might even
purchase a back issue, I'd be grateful.
Oh, one thing. The authors were right
about "P.A. Primer." They probably
could go on forever writing about it. In
fact, they ought to make it a permanent
column in the publication. Please let's
have more of the quality info MR has
been putting out... and keep the language down to earth. You've got my subscription!
-T. Roberts
New York, N.Y.
Issue Vol. I No. 5, which includes "P.A.
Primer Part I" is still available. Simply
write to our Subscription Department
and request them ($1.75 per issue).
Excited Reader
I have received several issues of your
magazine throughout your first year
through various local music outlets. I
recently subscribed, so that I would not
miss any future issues.
I am excited over your news of being
published monthly, and congratulate
and wish you the best of luck with this
move. It looks like I'll have to renew my
subscription sooner than I thought!!
Is there any possibility of your doing
an interview with either the group, engineer, or producer of America? I find articles which detail style, technique, etc.,
in the studio, are very helpful and give
me ideas to work with when I record.
Thanks for your great contribution to
the world of music and recording.
-Donald R. Goldberg
Hamden, Conn.
It's
Address
City
Late
me invaluable information needed to
learn my trade. I am a staff assistant at
Sound Ideas Studios, N.Y., and will be
the first to admit that I am not a terribly technical person. So when reading
Zip
We're Down To Earth
First off, I wish to commend you on
your excellent publication. It has given
a
Long Way to Argentina
I would be very pleased to receive the
following information. I am a musician
in my free hours and I want to buy
CIRCLE 66 ON READER SERVICE CARD
6
MODERN RECORDING
The only pickups
players
ask for
by name.
New in'77
Strat Replacement Pickup
Precision Bass Replacemert Pickup
How do you choose a pickup? You can't
hear and compare different makes in most stores,
so which do you choose?
Rick Derringer chose DiMarzio. So did Ted
Nugent. And Roy Buchanan. And Kiss & Lynyrd
Skynyrd. In fact, DiMarzio pickups are used by
more musicians than any other pickup on the
market.
These professionals have discovered DiMarzio
pickups offer them the sound they want, from our
Super Distortion Model (the hottest pickup on the
market) to our vintage PAF to our new Acoustic
Pickup.
But, the proof is in the playing, because that's
when you can't afford to be fooled. We know it.
You know it. That's why you should choose
DiMarzio.
DiMarzio
Musical Instrument Pickups, Inc.
Dept. TB, 643 Bay St., Staten Island, N.Y. 10304 (212) 981 -9286
Write for a free catalog on our
full line of pickups for guitar, bass & piano.
Available at fine music stores throughout the U.S.
Exclusive Canadian distributor: GHI Music Sales, 5000 Buchan St.,
Suite 506, Montreal, Quebec H4P 1T2
Super II
The Super II is a budget priced, black
body version of our Super Distortion
model, with slightly less output and
increased high end response. Easily
adapts to any electric guitar.
On stage,
everywhere.
CIRCLE 70 ON READER SERVICE CARD
Before
you buy
stereo
headphones,
get
some
good
advice.
some good instruments to play on and
record with in my house or for my
friends. While reading your magazine, I
saw some interesting advertisements like
the one from Ibanez guitars. I have
never seen that advertised guitar here in
Argentina. What information would I
need to buy that guitar which I have
seen in your magazine?
In Argentina, your magazine arrived
very late, I have just received the Jun/Jul
1976 issue.
-Mariano Cesar
Buenos Aires, Argentina
We suggest that you write directly to Ibanez at 1716 Winchester Road, Cornwell
Heights, Pennsylvania 19020, and inquire
if they have a distributor in Argentina
or are available from them by mail.
Your magazine will arrive late because
it is being mailed by boat. If you want it
to arrive promptly, it would have to be
sent air mail at an additional cost of
$1.08 per issue or $12.48 a year for
postage alone.
Credit Due
Theirs:
Julian S. Martin
HI -FI STEREO BUYERS' GUIDE, March -April, 1976
"Superb from every viewpoint. An outstanding achievement in headphone
design. One of the most comfortable."
The Len Feldman Lab Report
TAPE DECK QUARTERLY, Winter, 1975
"Response of these phones extends uniformly from 20 Hz to over 22,000 Hz
with no more than ±2dB variation over this entire range... this is nothing
We neglected to note that the photos
which appeared with the article, "Crosby, Stills and Nash: Recording Again,"
by Stan Soocher in the July, 1977, issue
of Modern Recording were the work of
Barry Paul Levine.
In that same issue, Ed Perlstein was
responsible for the photos which appeared with the cover story, "A Session
With Patti LaBelle," by Steve Whiting as
well as the cover shot.
We regret these oversights and would
like to take this opportunity to rectify
the situation.
-Ed.
Blooming Engineer
short of incredible."
am interested in recording techniques
and it would be greatly appreciated if
you would be so kind as to send me
information regarding course descriptions at the Recording Institute of
America. Thank you very much for
your time in this matter.
I
New Equipment Reports
HIGH FIDELITY, January, 1976
"The sound quality the AT-706 presents Ito you] is exceptional: very wide
range and smooth...Within this excellent operating range the sound is
exceedingly clean and open...an extremely fine stereo headset."
If you asked the critics they'd tell you to listen critically to a variety of
products before you buy. We agree. Because the more carefully you listen,
the more you'll be impressed by the sound of Audio -Technica.
AT -706
Electret Condenser
Stereo Headset $129.95
Our finest Personal Transducer
audio-technica.
®
INNOVATION
PRECISION
INTEGRITY
AUDIO -TECHNICA U.S., INC., Dept.97MR, 33 Shiawassee Avenue, Fairlawn, Ohlo 44313
Available in Canada from Superior Electronics, Inc.
8
-Peter Jacobson
Saugerties, New York
We suggest that you write to the RIA
directly for this information. Their mailing address is 15 Columbus Circle, New
York, New York 10023. They will be
happy to forward the information that
you want, but are flooded with like requests, so be prepared for a bit of a wait.
4
MODERN RECORDING
dbx noise reduction
signal processing
Tape noise reduction for the professional studio
216 16-channel
simultaneous
record/playback
noise reduction
system
187 4- channel switchable
record/playback
noise reduction system
30dB noise reduction with 10dB more headroom
Reduces tape hiss to inaudibility
Preserves full dynamic range
Cable assemblies furnished ready to plug in
Spare two-channel 310D module included
Available on modular basis for as few as four channels, expandable to
24 or 32 channels
Electrically interchangeable and fully compatible with dbx 216 and other
professional studio systems
Remote control switching capability
K9 -22 single -channel
noise reduction card
replacement for Dolby "A"
Direct plug in replacement for the Dolby® CAT 22 card; converts Dolby 361,
M16 or M24 to dbx noise reduction
Fully compatible with other dbx professional noise reduction systems
Less than half the cost of a free standing noise reduction system
Carrying case available for easy portability
Tape noise reduction for the semi -professional studio
154 4- channel
switchable record/
playback noise reduction system (152
2- channel switchable system also available)
157 2- channel
simultaneous
record /playback
noise reduction
system
Single -ended inputs and outputs terminated in RCA type phono connectors to
interface with semi- professional recorders, mixers, etc.
Small package for ease of portability
Excellent choice for the small studio or location recordist
30dB noise reduction with 10dB additional headroom
Fully compatible with dbx professional studio systems
Inexpensive noise reduction system with professional performance
Rack mount option available for all dbx 150 and 160 series models
Compressor/limiters
True rms level detection
Compression ratio variable from
1:1 to infinity
Threshold variable from -38 to +12dBm
Low distortion even at high compression ratios
Wide dynamic range and low noise
160 single channel compressor /limiter
For complete information on these and
162 true stereo compressor /limiter
other dbx signal processing systems,
circle reader service number or contact:
dbx. Incorporated. 296 Newton Street
(617) 899 -8090
Waltham, Massachusetts 02154
CIRCLE 62 ON READER SERVICE CARD
TALK
"Talkback" questions are answered
by professional engineers, many of
whose names you have probably seen
listed on the credits of major pop
albums. Their techniques are their own
and might very well differ from another's. Thus, an answer in "Talkback" is
certainly not necessarily the last word.
We welcome all questions on the subject of recording, although the large
volume of questions received precludes our being able to answer them
all. If you feel that we are skirting any
issues, fire a letter off to the editor
right away. "Talkback" is the Modern
Recording reader's technical forum.
Graphic Equalizers Exposed
There appear to be two kinds of graphic
equalizers available on the market.
There are those that boost and cut, and
those that just cut.
I'm curious about whether or not the
"cut only" types could be used in exactly the same way as the boost /cut types
by positioning all sliders halfway down
before EQ -ing and then making a graph
by moving them up and /or down. If
the unit has a master gain facility, it
seems that this method is valid. It's been
my experience that when using a cut
only type I occasionally need to get
more from one set of frequencies (1 -2
sliders) and, therefore, must move all
the others farther down. If would obviously be far simpler and accurate to
just move the necessary sliders up. Are
there any unforeseen negative effects in
using such a unit this way?
-Jay Parks
Waterbury, Ct.
Your basic concept of the operations of
the graphic equalizers is correct. In answer to your specific question about the
"cut only" type being used in a similar
fashion to the other type, it will work.
10
You mentioned in your discussion that,
"if the unit has a master gain facility it
seems this method is valid." Most of the
"cut only" equalizers are passive -type
equalizers. When all of the sliders are in
the zero cut position the signal is going
into the unit and out of the unit at
essentially the same amplitude. Introducing a certain amount of cut with one
of the sliders simply means that you are
attenuating the amplitude of that frequency (or group of frequencies) with
respect to the rest of the spectrum. If
all of the sliders were pushed down to
maximum cut, then the whole audio
spectrum would be attenuated by the
amount specified by the manufacturer.
At that point, you have a signal going
into the unit that is considerably greater
in amplitude than the signal going out
of the unit. In other words, at its maximum cut position, the unit has an insertion loss basically equal to the attenuation capabilities of the unit.
You may use such a passive -type unit
in the fashion that you describe, that is,
putting sliders halfway down, with the
understanding that you are attenuating
the spectrum by that amount in your
initial setting. By increasing the setting
from the center point with each of the
sliders you are not actually boosting,
but merely attenuating that portion of
the spectrum less. In this passive -type
device, it is easy to degrade the signal to -noise ratio of your audio chain if you
are not careful to observe the gain structure of the system in which it is being
used. To briefly clarify gain structure,
I shall use the analogy of a turntable
with a very low magnetic pickup. In
order for it to be usable, we must amplify it quite a bit before it has the ability
to drive earphones or loudspeakers. In
the first stage of amplification, the signal, called a preamplifier signal, is
brought up to a more usable level. Following additional amplification in the
main amplifier, the signal strength is
increased to the point where it will
perform the functions of driving loudspeakers or headphones. By design,
in any given system there is an optimum
step -by -step increase of gain to provide
the best signal.
Since the amplifier is not selective, it
also amplifies noise, present at its input,
in a similar fashion to the signal. If, with
a given cartridge, preamplifier, and
amplifier combination, I had a certain
signal -to -noise ratio and I introduced
attenuation between the magnetic pickup and the input to the preamplifier,
I would then find it necessary to increase
the overall amplificiation to bring my
signal level up to what it was before the
addition of the attenuation. When I do,
it will increase the noise along with that
weaker signal and therefore degrade my
signal -to -noise ratio.
Applying this to the use of the passive type equalizer you are describing, you
must be careful that the attenuation
introduced at a chosen point on the
signal path will not appreciably affect
your signal -to -noise ratio. Since there
are so many graphics built by so many
different manufacturers, it is hard to
specify exact usage of your particular
unit. However, it is preferable to obtain
a unit which has no insertion loss; in
other words, a device with built -in
amplification to overcome the insertion
loss of equalization circuitry. However,
using a passive equalizer in the fashion
described should not have any adverse
effect on any other aspects of the signal
quality.
-Skip Frazee
Manager
Sound Techniques
Dallas, Tx.
Helpful Information
In your May, 1977, issue, Norman Eisenberg and Len Feldman tested the
Tandberg TCD -330 cassette recorder in
MODERN RECORDING
Number
One EQ
their Lab Report (pages 54 -57). In th
General Description, they note that the
TCD -330 is equipped with a mechanical
override eject button at the rear of the
unit to eject a cassette in case it is left
in as the power is being turned off. Why
is there a need to eject the cassette before turning 3ff the power? I've never
before heard of this being harmful to
the tape. Is it?
-Pete Giannosa
Detroit, Mi.
-
$65 ° °%h.
IN STOCK RIGHT NOW
FOR FAST DELIVERY
We're not sure just how many ten
band octave equalizers we have to
sell to become the World's No. 1
supplier but the more you know
about our graphic (and all the others)
the better our chances become.
It is not necessary to eject a cassette
from a cassette deck prior to turning the
power off. However, it is suggested that
your deck be put in the "stop" mode
prior to shutting the power off to insure
that all cassette drive parts are disengaged. Many cassette decks depend on
mechanical shutoffs to disengage the
pinch roller or rollers from capstans
and, if left engaged without movement
for long periods of time, flat spots may
form resulting in an increase in flutter.
The same is true of the rubber drive
wheels (idlers) inside many cassette
decks.
On the Tandberg TCD-330 all functions are full logic (electronically controlled) so turning the power off automatically disengages all drive parts. The
mechanical eject button on the rear of
the machine is a convenience to allow
you to remove a cassette from the
machine without turning the power on.
-Robert S. Blumberg
East Coast Regional Sales Manager
Tandberg of America, Inc.
Armonk, N.Y.
We've delivered over 2,000 of these EQ
kits since the Editors of Popular Electronics selected it for the cover story in
their September '76 "Special Focus on
Audio" issue. This broad range of customers
provided an ideal "proving ground" for ease of assembly, reliability and customer satisfaction
in general.
Oh, Those Blinking Lights!
I have a Sansui 551 receiver whose
lights begin to pulsate and blink when
the volume control is turned to "4" or
higher. I replaced the power amplifier
in it just last October. The system I'm
using it in consists of Bose 301 speakers
and a BIC 940 turntable in which I have
an Empire 2001E3 cartridge. Could you
tell me what might be causing this malfunction or how it can be stopped?
-Joe Donohue
West Hempstead, N.Y.
fessionals.
After sending your question to Sansui,
we were advised that they felt the best
way to handle this question was to ask
you to send your receiver (along with a
detailed description of the problem) via
United Parcel Service prepaid, together
with proof of purchase, to their offices
at 55 -11 Queens Blvd., Woodside, New
York 11377. Mark it to the attention of
SEPTEMBER 1977
Musicians, recording studios, system installers, radio and TV broadcasters, equipment manufacturers, research labs and hundreds of private citizens ranging from eighth -graders to aerospace electronics designers have ordered, received and built the EQ -10 kits. Our record speaks
itself.
for
Only two kits have been returned for factory troubleshooting and not one customer has ever
a refund after seeing the kits....out of over 2,000 kits delivered!
requested
If you need graphic equalizers for any system where performance, reliability, hum- immunity
and versatility cannot be compromised regardless of cost or, if you're "bargain- hunting" but
refuse to accept downgraded quality in your audio system then we're your equalizer supplier.
Example: Our basic per -channel kit cost is only $65.00 and we sell direct to you by mail.
guarantee every part in every kit to be 100% functional and up to specs. We give you 90
days to exchange below -spec or defective parts free. We pre -test every active device in every EQ
kit before it ever gets packed. We offer system packages for mono, stereo, quad and eight channel applications with or without power supply kits and cabinetry and with system and
quantity discounts available.
We
Every kit comes with our 32 page Assembly, Installation & Applications Guide and all necessary parts. The slide controls are precision metal -shielded types with metal levers, hydraulic
damping and long -throw center -detented action. Noise and distortion figures are guaranteed
(at all EQ settings) to levels that make some so- called "pro" gear look bad by comparison.
Each individual -channel module is housed in a solid metal die -cast enclosure suitable for direct
19" rack or custom mounting. Both balanced and unbalanced I/O facilities are provided. We
mean it...real quality and real value! This unit was designed by a professional for use by pro-
For complete details, specs, ordering directions and a personalized order blank just send your
name and address to us on a postcard. We'll respond FAST! Guaranteed!
Delta -Graph
Box 247 Northgate
r
(206) 525-7196
Seattle WA 98125
1
LIwould like more information on the DELTA --GRAPH EU-10.
Please Rush
'
to:
Name
Address
City
State
MR7709
Zip
L
11
Mr. S. Fujii, Service Administrator, who
will see that Sansui's technical people
-Ed
get right on the problem.
Figuring Speaker Impedance
I'm building my own speakers and have
come upon a stumbling block -what is
the proper way to figure the impedance? I have three 8-ohm speakers with
an 8 -ohm crossover plus another 8 -ohm
tweeter with capacitor. When measured
on the ohmmeter, the impedance equals
5 ohms. I've been told that 8-ohm
speakers should be rated no higher than
4 ohms. However, I like the sound of
the bass better at an 8- or 16 -ohm rating.
Is 4 really the necessary rating or is an
8- or 16-ohm impedance allowable?
-Daniel Blanchard
Wheeling, W.Va.
You seem to be confusing two terms:
impedance and resistance. The impedance of a loudspeaker consists of resistive and reactive components, which
cannot be added in a simple manner
since the inductive reactance is 90 degrees out of phase with the resistive
component of the impedance. Your
ohmmeter reading of 5 ohms for the
combination of drivers you have assembled is typical of an 8-ohm system. As
for how to "rate" the impedance of
your home -built speaker system, we
don't see that this really makes much
difference. If you are using it with a
to
speaker system.
You should also be aware that the
nominal impedance of a loudspeaker
system is just that -nominal. Impedance
of loudspeakers varies with frequency.
16
14
12
10
8
6
4
2
o
20
100
1K
FREQUENCY
Typical impedance
vs.
10K 20K
- Hz
frequency curve of
solid state amplifier, that amplifier can
handle nominal impedances of 4, 8 or
16 ohms with equal ease. The only difference will be in the total power which
OCTAVE BAND ANALYZER
FEATURES
will be transferred from amplifier
Simultaneous display - TEN one octave bands -31.5 Hz to 16 kHz
Light Emitting Diode readout
Meets ANSI 1.11, Class Il for
Octave Band Filter Sets
Fully calibrated in dBspl
Broadband
dBspl Line Input -calibrated in dBm Flat or A-weighted measurements Hand held- battery operated (rechargeable nickel-cadmium
cells)
Precision microphone, carrying case, noise generator,
battery charger included
APPLICATIONS
Sound system set -up
Noise surveys
Octave equalizer
adjustment
Speaker checkout
At Horn alignment
Room surveys and
speaker placement
a
loudspeaker system.
Thus, using proper instrumentation (not
just an ohmmeter) you may find that
your system measures 8 ohms at 400 Hz,
or thereabouts, while at the low frequency resonance of the system, the
impedance may well rise to twice that
number or more and at some other
frequency, the net impedance may dip
to below 8 ohms. The only thing to be
sure of is that the impedance remains
above the 4 -ohm point throughout the
audio range so that your power amplifier, when driven to near its rated power
output, does not draw too much output
current and endanger the life of the output transistors. Most better solid -state
amplifiers are equipped with protection
circuits which would disconnect signals
from the output if that occured.
-Len Feldman
Audio Editorial Board
Modern Recording
More on Cleaning Heads
[The following is yet another response
to the Talkback query, "Cleaner Heads,"
which appeared in the August issue of
Modern Recording.]
have found 99% anhydrous (water free)
isopropyl alcohol, which contains no
"perfume" or other additives, to be
most satisfactory. This solvent should
be available at local drug stores although
you will have to ask for it. It is used to
clean oxide and edit pencil deposits
from tape heads and all elements of the
I
ALSO: Active and passive
equalizers Other real time
analyzers
Dealer inquiries invited
\QD \)
"
ayHM,
Call or write tod512/892
: W-0752
ITE INSTRU
P.O. BOX 698
AustinENTS,
Texas
78INC.
767
CIRCLE 40 ON READER SERVICE CARD
12
MODERN RECORDING
tape path, i.e. tape guides, tape lifters,
capstan and pinch roller.
Cleaning is accomplished by rubbing
tape path elements with alcohol- saturated cotton -tipped swabs, repeated until
no oxide or other foreign matter appears on the swab, followed by dry
swabs to remove excess solvent. It is not
recommended to attempt to clean the
pressure pads which are found on some
consumer equipment. These pads should
be replaced before they become loaded
with oxide.
-Don Cuminale
Technician
Mediasound Recording Studios
New York, New York
Realistic 999 -B 3 -head tape
deck which performs relatively well for
me in every way but one. When it is in
the "play" mode, the motor becomes
extremely noisy. This does not happen
when it is in rewind or fast forward. Do
you have any idea why this occurs and
how I can make it stop? I'm using it
with Bose 301 speakers -could they
have any bearing on this problem?
-Joseph Stephens
West Hempstead, New York
a
sent this question on to Realistic but
people there felt that without
actually seeing your machine they
couldn't accurately diagnose the problem. They did tell us, however, that
there is no inherent weakness or problem with the motor of this model. Your
problem is most probably an internal
one and is not affected by your system.
They advise you to take it to the Realistic dealer nearest you for a thorough
We
the
going over.
Beat the drum
The bass c rum,
A Realistic Problem
I have
Beyer lets you
-Ed.
will it come through louc
are clear with full cepth
nc sharo attacK,
r will your cherishec
performance oe
ecuced to o
stunted inump?
Beyer
know the
oass cram anc
its critical recuirements.
capture its tonal
impact they perfected
the V101.
\ow your drums can take a beating!
To
Splitting Mic Signals
In reading all of the articles on "live"
P.A. set -ups of actual groups, I notice
that they all use a separate mixing board
and monitor board.
As soundman for a rock band, I am
currently using a mixing board with
built -in monitor sends. However, I cannot hear what the monitors sound like
on stage so I would like to switch to
using a separate monitor board approach.
Unfortunately, your articles have
never explained how the mic signals are
split to go to the two separate boards. Is
there a device that splits those signals to
go to each board or does the signal go to
one board and then the other? Both
methods seem very impractical. Split-
LBEYE
CYI>IAMIIC
J
Distributed by Hammond Industries Inc.
the microphone people,
155
Michael Drive, Syosset, NY11791(56) 364
-1
ADO
CIRCLE 24 ON READER SERVICE CARD
SEPTEMBER 1977
13
ting mic signals seems like it would upset the impedance and levels of the entire system.
Going from one board to the other
would require special pre -fader balanced
line outputs on each channel since the
boards are quite far apart. Please explain
the method or methods used to accomplish this.
-Steve Mandel
Elmont, N.Y.
The signal is usually split at the mic connector box on stage, with separate lines
running to the monitor board and the
main board. If expense is of little concern, the most fool -proof method of
splitting is to use transformers with multiple secondaries, connecting the mic to
the primary, one secondary to the main
board, one to the monitor mixer, and if
required, additional secondaries may be
used to provide isolated feeds for recording, "live" radio or TV, etc. Transformers for this application are made by
Sescom and other manufacturers of high
quality mic transformers. Primaries and
secondaries should all be in the microphone range (150 -300 ohms) and of
course, the transformers must be able
proIeMonciI series
Have you been impressed (in the past) with a so called "pro series" of equipment
only to find that once the tinsel and glitter has worn off, all that's left is a toy?
If so, HEIL SOUND could be the answer to your audio dilemma. Since 1970
we've been producing rugged and reliable touring gear for such discrete
professionals as The Who, Peter Frampton, Joe Walsh, BTO, and a host of other
major concert artists. HEIL knows what it takes to do a quality job on stage and
has just created a line of equipment that rivals any in the industry at a price that
will please even the most modest budget.
The "Professional Series" of amplifiers
uses the same "Mod- U -Pac" plug in
our renowned Omega line thus allowing you -the musician -to carry a
spare side of your amp for instant repairs on the gig.
module
as
PRO -MIX
Our new and exciting 8 channel mixer is a low impedence cannon type with unbalanced inputs. Bass
and treble controls are ± 20dB for superior EQ. The
effects are preEQ and levels from the main or effects
outputs are monitored by a high quality 4" lighted
VU meter.
$29900
PRO -GRA
NI.I
$19900
PRO -XO
$13500
PRO -100
$29900
PRO-200
$42900
This dual channel graphic equalizer has 10 bands and
is now available at a very favorable price, in fact we
assure you that there's no better value on the market
today. It's black anodized with a standard rack mount
panel and comes equipped with level controls for each
channel and defeat switch.
Featured here is a two way electronic crossover model
with 800 HZ 12dB pre- octave and separate level controls for high and low outputs. Also contained in this
unit is a 19" x %" black anodized, standard rack
1
panel.
Included in this package is a dual channel 85 watt (per
channel) unit at .1% dist. and 4 ohms per channel using our Omega 100 series plug in modules. Balanced
line inputs, binding post outputs and a black anodized
19" x 3v1" standard rack mount panel are also standard.
u
1
$58900
ALL PRICES ARE
SUGGESTED RETAIL.
at all).
Looking at the two solutions and their
relative costs, I think I would try the
direct paralleling first (assuming you are
only looking for a two -way split;
beyond that, transformers would be indicated). You can always buy the transformers later if it doesn't work out,
which would be easier than trying to unload them when you find out that they
really weren't necessary in the first place.
-Bruce Howze
President
Community Light & Sound, Inc.
Philadelphia, Pa.
Different Driver
Presented here is a dual channel power amp with 150
at .1% and 4 ohms per channel using our 200 series
plug in modules. Balanced line inputs, binding post
outputs and a black anodized 19" x 5h" standard
rack mount panel round out this package.
Usages
How does a compression driver differ
from regular drivers? Where would you
use a compression driver? (Indoors,
outdoors, small or large rooms ?)
-C. Goutas
PRO-400
11
to handle the highest input level anticipated without going into distortion.
You will find that transformers of this
type will probably fall in the $20 to
$30 range. If this seems a bit steep (like
if your monitor mixer didn't even cost
that much per input) you can be brave
and simply connect the inputs of the
two mixers in parallel. This is not really
as drastic as it sounds. Most mic inputs,
although rated for use with input impedances of 150 -250 ohms, are actually
of a much higher value (usually around
1000 ohms or more). Thus, two such inputs in parallel would still only represent 500 ohms and would not bother
the mic. Assuming that both mixers use
transformer inputs, isolation should still
be maintained by such a splitting system,
although you may have to fiddle with
your grounding points a bit to remove
any resultant buzzes or hums. It might
also be helpful to put both mixers on
the same power line. One conceivable
problem that might result from such a
system is that if either mixer uses resistive input padding before the first
amplification stage, there might be some
interaction between the two mixers if
the pads of either do not represent a
constant impedance over their range
of settings. I think this problem would
be barely noticeable (if it even existed
Our top of the line model is loaded with 250 watts
RMS at .1% distortion into 4 ohms per channel
using our popular 400 series plug in. Balanced line
inputs, binding post outputs and 19" x 7" standard
rack panel complete this winner.
Heil Sound Company
No. 2 Heil Industrial Drive
Marrissa, Illinois 62257
Phone 1-618 -295 -3000
NEIL
SOUND
San Francisco, Ca.
Regular drivers are what most people
call cone speakers. Compression drivers
are usually called plain "drivers." The
most typical application for a compression driver would be coupled to a horn
for reproduction of high frequencies.
All kinds of combinations of both types
CIRCLE 32 ON READER SERVICE CARD
14
MODERN RECORDING
of drivers constitute most sound reinforcement and studio monitor systems
around today.
Compression drivers are named so,
because they work into a "higher compression" than regular drivers. They produce sound pressure level (SPL) by
creating a large compression on a small
volume of air (between a driver's diaphragm and its phase plug). Regular
drivers accomplish much the same thing
by creating a small amount of compression upon much larger quantities of air.
I personally feel that the main thing
compression drivers have going for them
is that they are always used in conjunction with horns. This combination is
unbeatable for overall efficiency and
control of sound dispersion. Compression drivers (as well as horn loaded
speakers) are almost always used for
creating high SPL in large rooms. In
small rooms, with lower requirements
for SPL, there are a lot of other transducers (such as electrostatics) which will
hold up better to the scrutinizing ear.
In all types of rooms and situations, cone
speakers are what you will more than
likely be hearing for bass and low mids.
-Richard Krueger
Gallien- Krueger
Campbell, Ca.
Shure's Side of the Story
[The following is another response to
Paul Tenhula's question, "Capacitance
Requirements," which appeared in the
August, 1977, Talkback section on
page 13.]
Mix Down Like
a
Pro for $20
The KIK Mixdown Box lets you Ping Pong channels easily.
Transfer tracks to give your 4 Channel tape recorder a 7
Channel capacity. No channel will be more than one generation away from the original. The KIK Mixdown Box is
available in 3 versions, a 10,000 Ohm model, or a 100,000
Ohm unit, or the Dual Impedance model for 10,000, and
100,000 Ohm operation. Die -cast unit construction. 4 in,
and out. The Mixdown Box has no active devices to generate hiss, or distortion.
1
The KIK Mixdown Box Warranty is for a full year against
a failure of any kind, under normal usage
To order, state
which model you want;
Model 0K
@
@
@
1
Model100K
Dual Impedance Model_
Send cash, check, or money order plus
residents, add 6% state tax) to;
$1
$20 each
$20 each
$35 each
handling, (CA
KIK 6620 Whitsett Ave., North Hollywood,
CA 91606
Please PRINT clearly to insure prompt shipment and allow
2 -4 weeks for delivery.
CIRCLE 58 ON READER SERVICE CARD
=ttAUDIOARTS
t
ENGINEERING
286 DOWNS ROAD, BETHANY, CT. 06525
EQUIPMENT DESIGNED TO LAST
PARAMETRIC EQUALIZERS, TUNABLE ELECTRONIC
CROSSOVERS, FEEDBACK SUPPRESSORS,
AND MIXING SYSTEMS
Many audio manufacturers do not realize the need to include certain specifications critical to the match of the phono
cartridge to the preamplifier circuit.
These specifications are important and
are necessary for the flattest possible
frequency response of any stereo system.
The specifications which are essential
for this critical match -up are the phono
preamplifier input termination, which is
made up of the input resistance and the
input capacitance, the capacitance of
the tone arm wiring, and the capacitance of the cables to the preamp. These
values should agree with the termination
recommended for the phono cartridge.
In answering your questions, the input
resistance of the Dynaco PAT -4 preamplifier is 47,000 ohms. This figure
just happens to match the optimum
load resistance of the Shure M91ED
Cartridge, which is specified at 47,000
ohms resistance in parallel with 400 -500
Pf total capacitance per channel. HowSEPTEMBER 1977
0
PUMICE
RUMBLE
REVERS
IN
STOCK AT:
Audio and Organ Services
2780 Erie Boulevard East
Syracuse, N.Y. 13224
Ludwig Sound and Stage
164 Washington Avenue
.North Haven, Ct. 06473
CIRCLE 29 ON READER SERVICE CARD
15
ever, the load resistance can be up to
At those rare and magic times, when the heavens are in proper alignment, a
wonderful old Wizard visits this planet from the Land of Ohm. With him he brings
marvelous extraterrestrial electronic devices to delight musicians everywhere.
Spoke the Wizard, "Call this the Ibanez Phase Tone, a mini- phaser so compact and
durable it will astound you. For those who wish to have more control over their
sound. here is the Ibanez Phase II, with a depth control for phase effects from a
subtle hint to a bold sweep."
For musicians who want sustain with no distortion. I give you the Ibanez Compressor.
It will help you to stand out and be heard, without having to shake the heavens with
volume. And for those who want a bit of grit with their sustain, here is the Ibanez
Overdrive, a hard-driving sustain and distortion device."
70,000 ohms with almost no audible
change in frequency response. It should
be noted that total capacitance (400500 Pf per channel is required for the
M91ED) will include tone arm wiring,
cable capacitance, and the preamplifier
input circuit. In the case of Shure
cartridges and other magnetic phono
cartridges, if the total capacitance per
channel is less than the recommended
value, the result will be a gradual slope
down from 5 kHz to 11 kHz, and will
rise slightly in response above 12 kHz.
If the total capacitance is greater than
the required capacitance of the phono
cartridge, the response will rise in the
region from 5 kHz to 11 kHz, with a
slight roll-off above 12 kHz. These
changes in frequency response are dependent upon the changes in capacitance, and will only be audible if the
capacitance mismatch is significant
(such as 200 Pf above or below the suggested capacitance value). It should be
noted that varying capacitance values
and their effect on response will be audible to some individuals and not to
others, as well as being desirable to
some and not to others, depending on
the listener's preference.
What is needed with your equipment
for a match in capacitance values is 270
Pf per channel. This will result in a total
of 400 Pf per channel and will produce
the flattest response for your system.
-Gary Rogers
Sales Engineering
Shure Brothers, Inc.
Evanston, Il.
Sound Modifiers
My question concerns outboard sound
modifiers. In what order, and why, in an
With a snap of his fingers the Wizard produced the Ibanez Renometer. "Captured in
this compact package is a veritable rainbow of tone color, with 5 bands of equalization
and a preamp /tone booster - perfect for any instrument or vocal system.Then reaching deep into his bag, the Wizard said, "Now this is a most interesting
effect - the Ibanez Stereo Box. It will give you an automatic variable speed pan
between two amplifiers or two channels of the same amp.is the device of which 1 am most proud ", said the Wizard with a grin. "The
Ibanez Flying Pan, a combination automatic panning device and state of the art
phase shifter which can make the sound of your instrument literally fly around the room.
"But here
a
And then, with a dramatic wave of his arms. the Wizard of Ohm disappeared into
cloud of smoke and a crackle of lightning - but promising to return soon with more
electronic marvels for musicians.
Fat9020.J27Fl,oadwar idano
a s
tllaO,.mCanada
E
Pray
M,.ea.rins
..
a,.tk,e
electric guitar system (from guitar to
amp) would you connect a wah -wah
pedal, fuzz, phase shifter, graphic equalizer and a linear booster or preamp?
-Charlie Moretti
Olyphant, Pa.
When connecting sound modification
devices in series, order is determined by
the desired effect and operational characteristics of each device. I suggest connecting the instrument's output into an
equalizer first if you wish to emphasize
its tonal characteristics or modify them
to emulate other instruments. Next in
the chain would be the distortion (fuzz)
device which adds variable amounts of
distortion and sustain. By placing a wahwah pedal next, the distortion products
and upper harmonics can be selectively
CIRCLE 57 ON READER SERVICE CARD
16
MODERN RECORDING
emphasized. A phase shifter or flanger
would be next, creating a comb filter
response. Last in the chain would
be a linear booster or preamp, primarily used to overdrive the Inputs of
the amplifier, creating amplifier induced
distortion.
The above devices are needed at other
points in the chain occasionally. A pre amp could be placed directly after the
instrument where low output levels are
encountered, permitting optimization of
dynamic range and reducing the chances
of hum and noise pickup through the
cables. An equalizer, if placed directly
before the amplifier, can compensate
for response aberrations of the amp
and speakers.
Reverberation, echo and other delay
devices would normally be placed near
the amplifier end of the chain. An envelope filter can be placed before or after
a distortion device depending on the desired effect. A limiter or compressor, if
placed directly after the instrument,
helps to reduce the possibility of
overdriving succeeding stages and adds
sustain.
Noise problems creep into any sound
modification system and are magnified by high gain devices such as corn pressors, distortion units and linear
boosters. A noise gate, if placed at the
amplifier's input, can be set to gate off
this residual noise while allowing any
signal above a certain threshold to
pass through unaltered. A number of
currently available noise gates also offer
direct tap facilities.
It is important to note that the desired
effect dictates order in many applications. For example, a wah -wah, envelope filter or phase shifter would typically be placed after a distortion device. However, if the order were reversed, then the frequencies at which distortion occurs could be controlled.
-Richard Neatrout
Chief Engineer
MXR Innovations Inc.
Rochester, New York
remedy this problem with switched
equalization and biasing. Tape manu
facturers, with increasing standardization of the biasing settings, are forced
into trying to make tapes which "fit"
the standards.
On professional tape machines, with
reproduce equalization, set correctly
to the prevailing standards, reproducing
tapes which are reeorded correctly to
THE NEW OCTAVE EQUALIZER
TWIN -GRAPHIC OCTAVE EOUAUZER
TO- 2208 -800 BALANCE 01/OUT
SWITCHABLE HI or LO IMPEDANCE
SWITCHABLE BALANCED or UNBALANCED INPUTS
SWITCHABLE BALANCED or UNBALANCED OUTPUTS
TWO SEPARATE MONO SECTIONS, IDENTICAL CONTROLS
L.E.D.'S FOR VISUAL INPUT /OUTPUT BALANCING
SWITCHABLE HI and /or LO SHELVING
SEPARATE ZERO -GAIN SPECTRUM CONTROLS
GOLD- PLATED CONTACTS ON ALL SWITCHES
ZERO -GAIN: Unity
20,480HZ
-
If different tapes are run on one tape
machine, with no change made to the
tape machine to optimize it for those
tapes, then the results will merely be
confusing. The greater the differences in
SEPTEMBER 1977
t:
0.5 dB, controllable 20-
-12dB.
RESPONSE: *0.5
6 dB,
dB 20 Hz to
20,480 Hz at zero setting.
DISTORTION: Less than 0.05% THD @ 2 volts.
RATED OUTPUT (600 -OHM BALANCED): +20
dBm into 600 ohms.
OUTPUT CIRCUIT: FET Op-Amps (Balanced or
Unbalanced).
MAXIMUM INPUT LEVEL: -¡-20 dBm.
EQUIVALENT INPUT NOISE: Below 90 dBm with
E.Q. switched in. Below 110 dB at max. oijtput.
EQUALIZATION FREQUENCIES: Each octave centered at 30, 60, 120, 240, 480, 960, 1520,
3840, 7680 and 15,360 Hz.
12 dB at center freBOOST /CUT RANGE:
quencies.
FREQUENCY
Taped Confusion
How much does different kinds of tape
really affect the record and playback
response on any type of tape machine?
Thomas Heiple
Lyndhurst, N.J.
those standards, will show differences in
noise, signal fluxivity at a specific distortion, etc.
It is under these conditions that valid
comparisons can be made. However, the
required adjustments in the recording
chain, to make a recording which conforms to a standard, and which also
optimizes the characteristics of that
piece of tape, may be most revealing as
to the important parameters of the tape.
-Alastair M. Heaslett
Staff Engineer
Ampex Corp.
Redwood City, Ca.
basic magnetic properties from those to
which the machine is set, then the greater the confusion. Tapes cannot, and
should not, be compared on this bass.
Consumer tape machines attempt to
'
(
ivouie 4oreg
FILTER TYPE: Toroidal and Ferrite -core.
POWER REQUIREMENTS: 120 ±15% VAC 50/
60 Hz less than 10 Watts or 240 -- 15% VAC
50/60 Hz less than 10 Watts.
FULL -SPECTRUM LEVEL: Front panel 18 dB,
variable master level controls.
OCTAVE -EQUALIZATION: 10 Vertical controls
each channel, IT 12 dB per octave.
E.Q. IN -OUT: Front panel pushbutton switch for
each channel.
TERMINATIONS: 3 -pin XLR's for 'Inputs and
outputs.
WEIGHT: 18 pounds.
SHIPPING WEIGHT: 23 pounds.
FINISH: Front panel horizontally brushed, black
anodized aluminum. Chassis cadmium plated
steel, with black textured finish.
1721 Newport Circle. Santa Asa. Cal"fernia 92705
FOR MORE DETAILED
CIRCLE 83 OI# READER SERVICE CARD
ORMATION, CIRCLE REA EER CARD
17
Eliminating Amplifier Noise
Is there something I can put between
the output transformer and the speaker
terminals to eliminate or cancel noise or
interference generated within the amplifier? I am trying an isolation transformer at the A.C. line and a noise gate
line driver at the output of the guitar;
from within the amplifier if the noise
is not caused by the plate capacitator or
other various noises generated within
the amplifier.
-Stephen Snell Brown
Ashtabula, Oh.
Unfortunately, no. Any device that
would be installed between the amplifi-
a
AREA IN
QUESTION
vi
Cl
TRANSFORMER
N
SPEAKER
P
U
T
R1
these are line transformers designed to
eliminate or cancel interference at the
A.C. line and at the output of the guitar
for noisy pick ups, ground- looping, or
A.C. line hum. I want to know if there's
something to place here (see drawing)
to cancel or eliminate noise coming
er and the loudspeaker cannot usually
eliminate noise. The best way to eliminate the noise problem is at its source.
The next best way is to stop the noise
from entering the amplifying system.
Some typical noise sources are florescent lights, universal motors (motors
without brushes), and light dimmers.
Keep in mind that noise comes in two
forms, conducted and radiated. Conducted noise is noise that travels on wires
(A.C. power lines) and can be eliminated by installing an A.C. line filter. Radiated noise is noise that travels in the air
(like radio waves). This type of noise
will change levels as you move around
the room. The most common culprit is
poorly shielded guitar cords. "Cheap"
cords usually have very poor shielding
properties. Also, poorly shielded guitar
pickups or controls that are not grounded can cause this problem. To cancel
A.C. hum, you should try the above
steps and /or purchase a good set of
hum bucking pickups for your guitar.
I would not, however, suspect the
plate capacitor of generating noise. Any
noise generated within the amplifer circuitry would usually be cancelled out
by the amplifier's feed -back loop, unless
you have a defective component.
Please note that if you don't have any
noise unless the guitar is plugged into
the amplifier, your amp is okay.
-Duke Aquiar
Chief Engineer
Acoustic Control Corp.
Van Nuys, Ca.
Gallien- Krueger advises you to check out the 1000 -1S before you buy any power amp.
Compare the 1000 -1S guaranteed specs.
Compare the 1000 -1S rugged construction.
(The Gallien- Krueger 1000-1S is the only professional quality amp that is rugged enough to be truly portable.
We do our own fabrication, build our own transformers, and print our own circuit boards. So we know.)
Compare the 1000 -15 sound. Then decide.
Sound advice. Take it from us at your Gallien- Krueger sound dealer.
Gallien- Krueger, 504 B Vandell Way, Campbell, CA 95008
OC
GALLIEN -KRUEGER
You'll hear from us.
CIRCLE
18
21
ON READER SERVICE CARD
MODERN RECORDING
We still make them like we used to!
We also still price them like we used to!
Two interesting events just happened that will change everything you thought about the price of tape recorders.
Most other machines will cost more. As new 15% tariffs push their price higher, those flashy inexpensive
tape recorders will become just plain flashy tape recorders.
Revox machines will cost less. As we switch to direct US distribution, we are able to reduce prices to our
1974 level. Which will save you money on every product in our Revox line.
Times are rapidly changing. So you have to really keep your eyes open as well as your ears. When less
costs more, and more costs less, here is the one name to remember.
Revox. You can't buy better at any price. Especially now that our price is less.
For more information about Revox contact:
ST
Studer Revox America, Inc., 1819 Broadway, Nashville, Tenn. 37203 / (615) 329 -9576
CIRCLE 52 ON READER SERVICE CARD
o)Cie,
In Canada:
:
REVOX
Studer Revox Canada, Ltd. / (416) 423 -2831
More On Impedance
Differences
(The following is another answer to the
question, "Impedance Differences,"
which appeared on page 13 in the Talk back section of the June, 1977, issue of
Modern Recording.
-Ed.)
In the course of his answer, there are
some misleading comments made by
Larry Blakely on impedances. He makes
what
is a most common error, but it
calls for correction, nonetheless. To aid
in the discussion of what really happens,
I have drawn an equivalent circuit for
the output of some devices.
The circuit is drawn in the form appro-
priate to "G," the output of the source,
being a constant voltage, before any
losses in its own internal impedance.
Now, if the generator, or output stage,
is a true constant voltage source, the
voltage across "G" will not change, regardless of the current drawn. That
basic property is characteristic of much
professional gear, particularly when the
unit is to feed a 600 -ohm (or other)
line. In that case, ZINT or source impe-
dance is 600 ohms, and with a 600 -ohm
load, the voltage out is voltage divided
equally between the internal impedance
and the load impedance. The result,
commonly observed, is that the voltage
at the output terminals of the unit drop
to half that of open circuit, or by 6 dB.
If, however, the generator /output has
limited power, or current, delivery capability, E OUT will not remain a constant as Z LOAD is made lower and
lower. When a load is applied equal to
the internal impedance in such cases,
the output may fall drastically (over 20
dB) and distortion rise sharply (over
100:1 in some cases).
The correct general rule, then, is to use
loads as recommended by the manufacturer. If the manufacturer does not specifically state that his unit will drive a
load impedance equal to the source
impedance, assume that you should use
a load impedance of at least ten times
the source impedance for minimum
loading and distortion. If this restriction
cannot be met, try to restrict the loading to that causing a maximum 2 dB
drop at the output terminals. Loading
greater than that might be acceptable
from a level standpoint, but the effects
on distortion should be checked carefully.
-Howard A. Roberson, P.E.
Sound Measurements,
Audio and Acoustical Evaluation
Pittsfield, Ma.
ASHLY P.A. PROBLEM SOLVERS
THE PROBLEMS:
Miserable acoustics, feedback, bland drum sound, hand held vocals,
distortion.
Sometimes it seems you can't win. You don't create these
problems, but it's your job to solve them.
.
.
SOLUTIONS:
Model SC -50
$299
suggested
Isst pr,Ce
Model SC -66
$599
suggested
list pre
Our SC -66 Stereo Parametric Equalizer is a powerful tool to combat acoustical
troubles and eliminate feedback. It lets you make things sound the way you want
them to sound. Our SC -50 Peak Limiter -Compressor controls peak levels to increase loudness and prevent distortion. Both are superbly clean and quiet and
will dramatically improve the quality of any sound system. Try them out at your
ASHLY AUDIO, INC.
1099 Jay St.
Rochester, N.Y. 14611
(716) 328-9560
dealer
inquiries
invited
ASHLY dealer.
CIRCLE 74 ON READER SERVICE CARD
20
MODERN RECORDING
SAE Power
SAE's goal today, just as it has been for
over 12 years, is the design and production of
fine audio com-ionents which offer the befit
value in both sonic performance and quality
construction. Our line of amplifiers stand
as a testament to this goal.
-
First, their design all SAE amplifiers have
fully complimentary circuitry. In this unique
design approach, not only the output (as in
conventional amplifiers), but the drive and
input stages, are completely complimentary.
This ensures low transient and s:eady -state
distortion, plus full stability and fast overload recovery. Combine°this with our high
slew rate for accurate transient response,
feedback gain controls which will not
degridate the input signal (2000, 2400L), and
monocoque construction with its low weight
and high reliability (2200, 2400L).
-
our most powlrfa amplifier, designoA for WO
26(0 - 40C Watts*
power hone environments. The 2610 eisures clean d -,amic reproduction at the highest powe levels.
-
combininc pe fornance and r_gability in a
Watts'
surprisingly compact package. This ar+plilier can reprcdLce the most
de-narding p-ogram material without s rair.
24110L - 200
The result is state-of-the-art performance,
but to realize this performance we must have
the second part of our goal production.
In order to ensure optimum performance
from these unique design concepts, SAE
-
retains total control over the manufacture,
selection, and assembly processes. We maintain 40,000 sq. ft. of production area where
the latest techniques in metal and circuit
board fabrication, component selection and
product assembly are employed. The result
of these efforts is the line of high quality
amplifiers pictured here, each an outstanding
value in its power range and each a true
SAE component where performance and
value come together that's SAE Power!
4
.
-
i
Spientific Audio Electrorics, Inc
-
Incorporating as advanced dreitrt and teci2.00 - 1C0 Watts*
nelog-, +he 2200 offers high levels of clarity and ie nition at a
popular power level.
power ratings are per FTC regaraments and are : tafed wr?h Etc
.aced correr
!meowing parameters: 201Iz to 2Ck.lr from 250 ntW
with ess than 0.05% Tot3/ Harnaair or Intermocute:ior distortion.
*411
t
P.C. Box 60271 Terminal Annex, Los Angeles, GA 903E0
CIRCLE 28 ON REALER SERVICE :ARD
1!)11/frfil
14NJ
vti
,sosh
mmk.
SCENE
By Norman Eisenberg
NAKAMICHI UPGRADES
NEW TOP OF THE LINE SPEAKER
The model AS-1348 is the new top -of- the-line
speaker system from Heath, the electronic kit
giant. Drivers include a 15 -inch woofer, two 41/2inch midrange units, and three 1 -inch dome
tweeters. The woofer faces the rear to enhance bass
performance when the system is placed near a wall.
The midrange drivers radiate directly forward,
while the tweeters are positioned forward, angle right, and angle -left. System response is claimed to
be from below 30 Hz to beyond 20 kHz. The
AS -1348 is mail -order priced at $269.95.
To get a free copy of Heath's latest catalogue,
write Heath Co., Dept. 350 -22, Benton Harbor,
Mich. 49022.
700 CASSETTE DECK
version of Nakamichi's 700 cassette
recorder, the 700II, is claimed to have greater
dynamic range, improved high- frequency headroom
and lower residual noise than its predecessor. The
playback EQ amplifiers have been redesigned with
A new
phase correction; mic inputs have increased sensitivity, linearity and dynamic range; the headphone amplifier has higher output. The closed -loop
dual capstan transport also has been refined with
fewer moving parts and a quicker fast -wind than
before. The head is an improved crystal permalloy
type with extended life and a precision 0.9- micron
gap, according to Nakamichi. The 700II's meters
provide an expanded scale, ranging from -40 dB to
+10 dB, and the record-level calibration controls
have been moved to the front panel for easier access. Bias and EQ are now controlled by two independent switches. A three -head configuration, the
700II has Nakamichi's patented record-head azimuth alignment beacon, plus feather -touch transport controls with IC logic, Dolby noise reduction,
memory rewind, 3-mic/line mixing, playback pitch
control and switchable MPX filter. Price is $950.
CIRCLE
11
ON READER SERVICE CARD
CIRCLE 6 ON READER SERVICE CARD
CLASS A POWER AMP
LOW COST DELAY SYSTEM
Designed for sound -reinforcement work in clubs,
theatres, churches and small auditoriums as well as
in the studio and "live " -performance applications is
Lexicon's Delta -T Model 92 time delay system
_
priced "well under $2,000." The model 92 provides
two adjustable audio signal delays of up to 120 ms,
each controlled by a front -panel knob. Also provided are input and output audio transformers, fail safe, audio bypass, silent power up /power down circuitry and rear -mounted XLR -3 connectors. A five position LED headroom indicator, calibrated in 10dB increments below limiting, simplifies level adjustment and verification. Designed for rack mounting and weighing 81/2 pounds, the Delta -T 92
uses Lexicon's proprietary floating point digital encoding techniques. Dynamic range is claimed to be
better than 90 dB; noise and distortion are rated at
less than 0.1 percent.
From Threshold Corp. of Sacramento, California
there is news of the model 400A stereo power
amplifier which, says the manufacturer, has a
patented active bias system that enables the unit to
operate in class A mode to 500 -watt transient output levels per channel, but without the efficiency
and thermal problems associated with conventional
class -A amplifier design. The conservative power
output of the model 400A is 100 watts per channel
into 8 ohms at 0.05% distortion, 20 Hz to 20 kHz.
At idle, the amplifier draws 250 watts, and it maintains its correct operating temperature without fan
cooling. Frequency bandwidth at small signal levels
is rated within +0, -3 from below audibility to 500
kHz. Protection circuits include current limiters
with analog controlled reaction times, thermal monitoring, output fuses and resettable circuit-breaker.
For each channel there are individual peak vs.
average output level readings. Price is $1,147.
CIRCLE 10 ON READER SERVICE CARD
"QUASI- MODULAR"
MIXING SYSTEM
The Chilton QM -1 system (the letters stand for
"quasi -modular ") is a flexible and adaptable mixing
system available in several formats: 12 inputs, 4
groups, 8 tracks monitor; 16 inputs, 4 groups, 8
tracks monitor; 24 inputs, 4 groups, 8 tracks
monitor; 16 inputs, 8 groups, 16 tracks monitor; 24
inputs, 8 groups, 16 tracks monitor. Numerous
features are standard, including 4 or 8 bus assignment routing, pan and remix on a separate stereo
bus, complete talkback, complete oscillator with 40,
150, 330, 1000, 5000 and 10,000 Hz on pushbuttons
(two may be pressed for additive frequencies), complete sub- grouping into stereo for P.A. through the
monitor mixing system, and more. Optional features include a choice of modules, faders, comp/
limiter and balanced outputs. Chilton -made in
England -is distributed in the U.S. and Canada by
La Salle Audio Products Ltd., Montreal, Canada.
CIRCLE
2
ON READER SERVICE CARD
CIRCLE 20 ON READER SERVICE CARD
BURWEN SHOWS NEW ITEMS
New products from Burwen Research include the
Transient Noise Eliminator TNE 7000 and five
stereo headphones.
The TNE 7000 -priced at $289 -is designed to
remove scratches, ticks and pops from discs; its
patented technology copes with transient noise on
disc surfaces. According to Dick Burwen, the TNE
7000 in combination with his Dynamic Noise Filter
1201A "offer the best total noise reduction capability available today."
The headphones include models PMB 6 and
PMB 8, described as top -of -the -line orthodynamic
units in which an ultra -thin voice -coil diaphragm is
positioned between two perforated sintered ferrite
disc magnets. The models PMB 4, PMB 40, and
PMB 20 utilize dynamic design. Prices range from
$39.95 up to $99.95.
CIRCLE 12 ON READER SERVICE CARD
MIC /PROGRAM EQUALIZER
Spectra Sonics of Ogden, Utah has announced its
model 501 Microphone /Program equalizer, a compact device designed to provide high and low frequency reciprocal equalization for use in recording,
broadcasting, motion pictures, sound reinforcement
and other audio applications. The equalizer is a
passive network that becomes an active feedback
element in conjunction with the Spectra Sonics
model 101 audio amplifier. The EQ /amp combination provides 40 dB of gain so that insertion loss for
the equalizer becomes zero, and a gain advantage of
about 14 dB over conventional passive equalizers is
obtained. Continuously variable EQ ranges are
about 8 dB of boost or cut at high frequencies, and
about 10 dB of boost or cut for the lows. Distortion
is claimed to be unmeasurable (less than 0.01 percent residual). The device is 31%2 inches high and
AKG REVISES
STUDIO MICROPHONE
Said to be completely redesigned and vastly improved vis -a -vis the older model C -414 is AKG's
new version, the C- 414EB, a studio -grade condenser microphone featuring twin diaphragms.
Miniaturization of componentry, says AKG,
weighs 11 ounces.
CIRCLE 19 ON READER SERVICE CARD
MINI MONITOR
Described as "the world's first miniature studio
quality loudspeaker" is the model 300 from Analog
& Digital Systems, Inc., Wilmington, Ma. The ADS
300 has an aluminum housing that provides the
smallest possible external dimensions for a given inside cubic volume. If the enclosure were made of
wood, says ADS, it would be at least fifty percent
larger. The woofer here is a 51/2-inch unit claimed to
produce bass down to below 50 Hz. A soft -dome
tweeter completes the system. The model 300 is
rated to handle power levels up to 50 watts of
musical material, and will tolerate peaks beyond
100 watts. Efficiency is fairly high, and the small
speaker is said to be capable of producing "amazing
volume." Impedance is 4 ohms; weight is 71/2 lbs.
Dimensions are 8.45 inches by 5.8 inches by 51/2
inches. Price is $140.
..........................
enables them to provide numerous practical performance features plus improved resistance to
rough handling. All switching controls are incorporated within the mic itself. The twin- diaphragm
design permits the user to select four different polar
patterns (cardioid, omnidirectional, figure -8 or
hypercardioid). For close -up recording, pre- attenuation levels of 0, -10 and -20 dB are provided. A bass cut filter with a better than 14 -dB /octave -slope provides response that is flat, or cut off at 75 Hz or at
150 Hz. Rejection of RF interference is aided by an
all -metal housing. Using a standard XLR connector, the mic may be energized via 12/48 V phantom powering to further minimize the possibility of
extraneous interference. The C -414EB is stated to
be extremely quiet with an equivalent noise level of
20 dB SPL. Optionally available with the mic is a
new elastic suspension, boom -mounting facilities
and wire -mesh windscreen. Professional user net
price is $495.
CIRCLE 5 ON READER SERVICE CARD
3M ADDS LABELS
Extra exterior drawer labels and insert cards for indexing selections now are available for 3M Company's "Scotch" C -Box cassette storage boxes.
Drawer labels are backed with pressure- sensitive
adhesive, and both the labels and the cards can be
typed or written on. A poly bag containing twenty five each of labels and drawer inserts costs under
$2. The C -Box storage system consists of plastic
boxes grooved top and bottom for locking together.
CIRCLE
1
ON READER SERVICE CARD
CIRCLE 13 ON READER SERVICE CARD
RACK 'EM UP
Rack- mounting of audio gear seems to be getting
more popular outside studios. Mitsubishi recently
made a rack -mount system available as a dealer
display only to learn that audio /recording enthusiasts began wanting them. Accordingly, the racks
are slated for consumer sale. Capable of housing a
fair assortment of audio units plus some records,
the rack is six feet high, rests on casters that can be
locked in place, and has openings in the rear to
facilitate component hookups. A real fancy touch:
the audio gear can be viewed through twin vertical
glass doors. Price is expected to be somewhere
above $100.
CIRCLE 8 ON READER SERVICE CARD
DON'T GIVE UP YOUR CONSOLE
The direct -to -disc recording technique has been getting a fair share of publicity recently as a few more
releases embodying this method have become available. In the direct -to -disc technique, the master
record is cut right during the actual performance.
No tape is made first, no retakes, no overdubbing,
no mixdowns and so on. Everything happens on the
spot and in "real time." Obviously this puts great
demands on both the performers and the recording
team, but the end results are claimed by its partisans to justify the rigors of the sessions. Cleaner
sound generally, and wider-range dynamics specifically are held as audible evidence that the direct -todisc technique is better than the existing tape -andmix method. If you want to sample this type of recording, check the list supplied in this magazine's
June 1977 issue which ran with Jeff Weber's detailed story on the whole process. To this list, by the
way, we can add one more -the first direct -to -disc
recording of classical music played by a symphony
orchestra. That would be the release under the
Telarc label of the Cleveland Orchestra, conducted
by Lorin Maazel, playing selections by Tchaikovsky, Berlioz, Bizet and Falla.
In a sense, direct -to -disc is hardly new. It was, in
fact, exactly how records were made in the early
days before tape, before mixing, before the concept
of a recording as a "production" rather than as
"eavesdropping with a microphone." The question
now bothering many in this field is whether we have
come full cycle back to where we started -that is to
say, are recordings made by modern tape and associated signal- processing techniques so hopelessly
inferior when measured against the sonic potential
of modern playback equipment that we must give it
all up in order to make clean recordings with full
sonic response?
Some purists insist it is just so. These devotees,
however, usually are connoisseurs of the listening
situation rather than practitioners of recording.
From a workaday standpoint their view on this may
be impractical, but who can deny that their prompt ings and criticism over the years have not spurred
the recordist to greater achievement.
Be that as it may, the fact that a few direct -todisc recordings have been made that do sound better in many respects than conventional recordings
does not in itself rule out the conventional techniques. I can make up a list of recordings that will
stand up to any comparison, and I know that most
of my contemporaries can do the same. Proving
what? Simply, that the secret to great recording is
to be found not so much in any overall method, but
rather in how the method is applied. It's not that
mixing is "bad" or "good" -but rather how good a
piece of gear is the mixer, and -just as important
how expert is the mixing personnel doing the job.
The vital elements in making really good recordings
remain the same: the excellence of the hardware
employed, and the knowledge, skill, and sensitivity
of the human being employing it.
-
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SOUND REINFORCEMENT . .. The
Trouper I Live Mixing System from UniSync, Inc. (742 Hampshire Road, Westlake Village, Ca. 91361) is a low -cost,
high -performance mixing console designed specifically for P.A. use. The
Trouper I is a semi -modular system
comprising an Output Control Module
($749), which contains eight input modules and all the controls for the various
outputs (and thus can function as a selfcontained 8 -input mixer), and an Expander Module ($698) which contains
ten input modules only. Each input
module has connections for a low impedance, balanced mic input, a high impedance, high level input, and output
and input jacks for an insertion point
for connecting limiters and such. Controls on each input module include a 20
dB mic attenuator switch, three -band
graphic equalizer, monitor send, solo
switch and channel fader. The output
section of the Control Module houses a
variety of functions including house and
monitor master faders with high -pass
and low -pass filters, echo send master
fader, house and monitor echo returns,
LED meter and headphone level control.
-
r
26
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J
Brand new from the people at Shure
Bros. Inc. (222 Hartrey Avenue, Evanston, Ill. 60204) is a moderately priced,
professional quality microphone, the
SM59 ($132). This new mic is a dynamic type and has a cardioid response
pattern. Frequency response is 50 Hz
to 15 kHz, and the response curve has
been designed for flatness and natural
reproduction rather than having the
usual presence peak in the upper -frequency range which can often lead to
harshness in a microphone's sound. A
special feature of the SM59 is a patented mechano -pneumatic shock mount
system designed to reduce handling
noise and pickup of floor or desk vibra-
1"-421,'a..
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The echo send is normally connected
to a built -in spring reverb unit, but jacks
are provided for send to and return
from an external echo, reverb, or effects
device in addition to connections for
main (house) and monitor outputs and
a headphone jack. The Control and Expander modules interconnect via a single
"umbilical" cable. Both units are rack
mountable, or they are available in separate or combined carrying cases.
INPUT EXPANDE R MOULE
4.+1
r
.
tions through the mic stand. A pop filter
is integral in the mic to protect against
breath sounds and wind noise while retaining a slim, modern appearance.
An interesting new line of sound reinforcement equipment has been introduced by Emilar Corporation (2837
Coronado Street, Anaheim, Ca. 92806).
First is the EH800 Exponential Horn, a
compact, cast -aluminum horn with an
800 Hz cutoff frequency. Energy distribution is f2'/2 dB over a 90 degree
horizontal range and 40 degrees vertically. The EH 800 directly accepts the
Emilar EA175 or EC175 compression
drivers, and other drivers with a one inch throat can be adapted. The EH800
horn is particularly noteworthy for its
very shallow design-it's only eight
inches from front lip to driver flange.
The EA175 and EC175 are 8-ohm corn pression drivers designed for use with
the EH800. Both models have a 1.75 inch voice coil/diaphragm, and the
throat diameter is one -inch in both cases.
The voice coil /diaphragm assembly was
designed for maximum ease in replacement, requiring only a screwdriver. The
EC175 has a power rating of 30 watts
RMS using pink noise band limited to
500 Hz to 5 kHz, and weighs five
pounds, while the EA175 is rated at 40
watts RMS, weighs eleven pounds, and
has 1 dB higher pressure sensitivity.
When used with the EH800 horn the
EA175 will produce 108.7 dB /SPL at
one meter with a 1 -watt input of band
limited rink noise. To round out the
MODERN RECORDING
line, Emilar offers the EW15, a 15 -inch
low -frequency driver, and the EX800,
an 800 Hz crossover network for 8 -ohm
drivers, rated at 100 watts RMS.
INSTRUMENTS.. .One of the most remarkable new products shown at the
National Association of Music Merchants
trade show held in Washington, D.C.,
back in March, 1976, was the all -electric Piano Plus from RolandCorp, US
(P.O. Box 22289, East Los Angeles,Ca.
90022). At that time, the instrument
was only available in a contemporary
spinet-type cabinet, but company
spokesmen indicated that a portable version was in the works. Roland recently
announced that the portable Piano Plus,
officially called the MP-700, is finally
available, and that the home version will
be made available in a variety of cabinets, including the HP -763 in Italian
Provincial, to complement any decor. All
the Roland Piano Plus models are purely
electronic instruments which have been
carefully engineered to have the same
sensitivity, touch and dynamics as an
acoustic piano and to sound like an
acoustic instrument. The 75 -note keyboard uses special piezo -electric elements to generate a control voltage proportional to the force with which the
individual keys are struck, making the
Piano Plus fully touch sensitive. Besides
the acoustic piano voice, which is remarkably lifelike in sound, the Piano
Plus has tab selected voices for jazz
piano, harpsichord and bass. In addition, electronic controls are provided
for variable decay time, glide and Roland's much -used "chorus" effect, and
two foot pedals for sustain and damper.
The biggest advantages of an instrument like the Piano Plus over the various electro- mechanical keyboards come
from the fact that it is purely electronic
and doesn't have strings, tines or reeds
to break or go out of tune. Tuning stability is consequently excellent, and occasional retuning is accomplished by a
simple series of precise screwdriver
adjustments. The HP-763 model is completely self- contained with its own solid state power amp and exclusive Revo
Sound speaker system housed in the
finely crafted hardwood veneer cabinet.
The MP -700, as befits a portable model,
is a separate keyboard unit with tubular
steel supporting frames for use with external amplification equipment. Available from Roland is the MPA -100, an
amplifier /speaker system specifically designed to fit under the MP -700 keyboard unit, and which also houses the
sustain and damper pedals for the keyboard. Roland calls the MP -700 Piano
Plus "the instrument the world has bee
waiting for," and while that is probably
an overstatement, the instrument is nonetheless a significant advancement in the
state of the art in electronic keyboards.
it; the selectable functions of the photo
control are swell, vibrato or waa -waa.
AMPLIFIERS... Beckman Musical Instruments has announced two new
models in Roland's Jazz Chorus line of
Model MP- 700 /MPA -100
Portable Piano & Sound System
Model MP -700
Portable Piano
News of an interesting and, we dare
say, unique synthesizer comes to us
from Audio Arts, Inc. (5615 Melrose
Avenue, Hollywood, Ca. 90038). The
new instrument, called the Stylophone
350 S, is made in London by Dubreq,
and is a very compact (five pounds) 44note synthesizer with a total range of
6'/2 octaves counting the upper and
lower voices. The unique feature of the
Stylophone is that it lacks a convention-
keyboard, but rather is played by
touching one of the 44 "keys" printed
al
on a flat metal plate with a special pencil -like stylus provided with the unit.
Also provided is a second stylus which
allows the user to play two -note harmonies. Above the touch -plate is a row
of eight 3-position rocker switches.
Three of these switches control the
three "expression" functions of vibrato,
reiteration and decay, and four of them
select the various voices of the instrument (4 "woodwind," 2 "brass," and 2
"strings "). The eighth switch selects the
function of the unique photo control,
which is operated by placing one's hand
over the control to block the light hitting
guitar amplifiers. The Jazz Chorus amp
line, which already includes a single channel 60 -watt amp with a single 30cm
(12 -inch) speaker and a dual-channel
120 -watt amp with 2 x 30cm (12 -inch)
speakers, features a unique vibrato /chorus circuit which produces frequency
modulation (vibrato) or instrumentdoubling chorus effects rather than the
usual tremelo (amplitude modulation)
circuit. The new models are the JC -80,
a single- channel 60 -watt RMS amplifier
with a single 38cm (15 -inch) speaker,
and the JC -160, a dual- channel, 120 -watt
RMS amp with 4 x 25cm (10 -inch)
speakers. The JC -80 and the "Effects"
channel of the JC -160 have controls for
volume, bass, mids, treble, distortion,
reverb, vibrato speed, vibrato depth and
a vibrato /chorus switch, while the "Normal" channel of the JC -160 has volume,
bass, mid and treble controls only.
In addition to a line of mixer/amplifiers and PA speaker systems, Osborne
Sound (7901 Palm Avenue, Lamont, Ca.
93241) offers two bass amplifiers and a
guitar amp. The G1501TR ($499.00) is
a single- channel, 200 -watt RMS, solid state guitar amplifier in a compact cabinet with 2 x 12" speakers. The amp has
controls for volume, bass, treble, tremelo speed, tremelo intensity and reverb.
The model B1502 bass amp is available
with either a 15 -inch folded horn enclosure ($579.00) or a 2 x 15" bass reflex
cabinet ($549.00). The bass amp itself
has "Normal" and "Deep" channels and
is rated at 100 watts RMS.
27
SEPTEMBER 1977
-
like? German, Danish, Japanese or
French?
.
11
1
-ome teeth in this story, let's use a real
spec sheet. These are the numbers and
Mic Spec Sheet
A.
Type
--
KM84
- Neumann
----------
KM84
Directional pattern
cardioid
Acoustical principle
pressure gradient
Frequency range
40- 20,000 Hz
Effective output level
38 dBm
ref leve' 10 dynes/cm'
F. E.I.A. rating GM
137 dBm
G. Output Impedance
150 balanced
(needs floating amplifier Input)
H. Equivalent loudness level
IEC
due to inherent noise
179
18 dBA
B.
C.
D.
E.
(0 dB =
--
2.10-'dyneslcm')
I.
Equivalent loudness level
due to inherent noise
(0 dB = 2-10-'dyneslcm')
K.
SIN ratio (A weighted)
L.
ref level = 10 dynes/cm' ® 1 kHz
76 dB
Max SPL for less than 1% THD
133 dB
--
DIN
45405-25 dB
-- --
Total dynamic range of the microphone amplifier
referred to I.E.C. 179 weighted equivalent loudness
level on line "H"
115 dB
N. Power supply
DC, + 48 volts, +6,
at 0.4 mA
M.
(Note' The letter
- ---
"J" is not listed in
8
the origine/ Neumann chart.)
references that you will find printed on
the sheet for a Neumann KM84 condenser microphone. At the present
time it has a nationally advertised
retail value of $260. It requires a
power supply. That's another $50.
What's a power supply? Have patience
ole buddy, we'll get to it in a while.
Let's start with the sheet.
On one sheet of specs we now have
dBm, dB, dBA, two government standards (IEC and DIN) with number
references and several other unspecified abbreviatons such as SPL and
EIA. Asking someone to explain all
this is going to take some time, and
it's just the sheet of numbers for one
little microphone. It gets even more
complicated when you have a big stack
of spec sheets and you're trying to
compare one product with another
product of the same type. Different
companies don't always use the same
reference points.
Well, that's what this magazine is
for. We'll try to make some sense out
of this mess, and be your "ole buddy."
To do the job we'll have to start at the
beginning and find out how sound is
measured and converted into all those
system numbers and references.
Our Debt to Ma Bell
Who started all this anyway? Sound
converted to electricity, so you could
do something about it?
Would you believe -Ma Bell?
That's right. The telephone company started it all.
When you start digging into the
beginnings of sound measurement and
electronics, Alexander Graham Bell is
usually there first, last and always.
The phone company has done almost
all of the research, both theoretical and
practical, about sound and sound
30
equipment. T
taffdards that they
set are still (wiitliminor modifications)
what everybody uses and deals with.
An Englishman by the name of Lord
Rayleigh gets credit for a lot of theory,
and actually comes first in many
basics, but the inventor of the microphone itself was Alexander Graham
Bell. After that, we are off and running
after the buck right along with the
phone company.
Now, if you think it's rough trying
to get a signal from your mic to your
tape recorder through ten feet of cable,
and then playing it back, try putting
your mic in Nutley, New Jersey, and
your tape recorder in Boston. That's
no joke, and the phone company had to
solve that kind of problem or go out of
business. Right away a lab was set up
to investigate everything that Alexander could think of about sound and
electricity -Bell Labs. One of the first
things they had to deal with was
developing a mathematical system of
units to work with that would express
large quantities of electrical change in
a convenient and easy-to -use format.
The original unit was called the "Loop
Mile." It represented the loss in signal
in two miles of standard 19 -gauge telephone wire. One mile out and one mile
back. This was changed to something
called a "transmission unit," which
then changed to a unit called a "Bel,"
in honor of Alexander. The unit proved
a bit large when things got a little
easier to achieve technically, so now
we have the deci -bel, or one tenth of a
bel. It has no absolute value, being a
measure of change expressed as a proportion, but can be nailed down to an
absolute value if you define a starting
point to work with. What went into the
cable to begin with? What's the reference? On our sample mic spec sheet we
have three methods of nailing down a
reference for dB calculations.
dBm -Zero dB equals one milliwatt
of electrical power into an impedance
of 600 ohms. Most of the dBs are
minus, or less than zero dB using this
reference.
dBA -This isn't a fixed reference,
rather it's a method of referring to a
non -flat frequency response. The "A"
curve. On the sheet an extra line is
added to define a start, or zero dB
point. It says that zero dB for this
reference is 2.10-' dynes/cm2. That's a
sound pressure measurement. Hang in
there, we'll get to it. Just takes time.
dB SPL -Decibels, sound pressure
level. This is usually assumed to be
referenced to the lowest level of sound
that an average person age 20 -25 can
detect at 1,000 cycles per second. (This
is line "L" on the sheet, maximum
SPL for less than 1% total harmonic
distortion.) This specification tells you
how loud a sound the mic can pick up
before it overloads -133 dB louder
than the quietest sound you can detect
at 1,000 cycles if you have "average"
hearing.
Finally we have something that
might be useful. Now we have to find
out how loud a noise our instruments
are going to make. What kind of sound
power is generated by music? Let's
charge ahead to the chart of ... Hold
it. Right here, ole buddy we had better
deál with what sound actually is. If we
don't get it over with now, the lack of
information will bite us pretty badly
later. How do you hear? Is your ear the
same as a mic?
Pressure Changes and Hearing
Pretty close. People "hear" by detecting changes in air pressure. The
same way a mic "hears." What is the
smallest change in pressure you can
detect and what are the units used to
describe that change? There are several systems. Here's the setup. One atmosphere, smog and all, has a static
pressure of 14.70 pounds per square
inch. This will vary with altitude and
the weather, but not rapidly enough to
detect as sound. People have difficulty
hearing twenty cycles of pressure
change per second so anything like one
cycle per day, or week, doesn't count.
You can ignore the weather, because
even though the changes are large,
they're too slow to hear. Also, one
pound per square inch is much too
large to use as a unit. So, let's split it
down to a unit that is small enoughthe microbar. 14.70 lbs /square inch =
1.013250 bar = 1,013,250 microbars.
At Bell Labs two research scientists
found that even a microbar was almost
too large, but it would do. They were
the guys given the job of finding out
how quiet a sound the "average
human" could hear. Fletcher and Munson found (among other things) that
the smallest change in pressure that
was detectable at 1,000 Hz was .0002
microbar. The tests were conducted in
a totally soundproof area, so only the
small change in pressure was part of
the measurement. This is now used as
the base line or zero dB point for sound
pressure level charts. Remember that
this measurement is a change in the
static pressure around the fixed
MODERN RECORDING
YOUR
NOME TOWN
TAACO
DEALER
to learn more about the Tapco 2200 Graphic
Equalizer, drop us a coupon and well send along
complete information and specifications. And we'll
include a complete list of home town Tapco dealers.
If you want
TECHNICAL AUDIO PRODUCTS CORPORATION
Reet. Send me information, specs, and dealer list.
Write:
Laurie Jackson Tapco, 3810 148th N.E.
Redmond, Washington 98052
name
address
city
state
zip
CIRCLE 53 ON READER SERVICE CARD
reference of one atmosphere, and this
is the whole number. 1,013,250.0001
microbar changing to 1,013,249.9999
microbar. That's O dB SPL at the bottom of our chart. At the top you have a
change of two whole atmospheres to
hard vacuum (no air at all) and that's
194.1 dB SPL. In microbars, 2,026,500
change in pressure. Sounds in the upper magnitudes of pressure change are
created by explosions and high -speed
aircraft shock waves. Not good for
your ears at all, and will literally "blow
you away." There are also several
other systems of measurement that
are used along with the microbar when
the sounds get loud enough to make
their unit quantities comfortable to
use. We'll stick them on the chart of
musical noises along with the microbar
scale -the dyne per centimeter
squared, and the Newton per square
meter. These number systems can also
be found on mic sheets, so you'll need
the cross references.
This kind of sound power chart is
usually filled up with noises. Jet
planes, trucks, gunshots and things
like that. We left in the gunshot, but
re -did everything else.
Some of you old pros reading this article may twitch a little looking at
these SPL figures. They look pretty
high compared to what you remember.
Well, get out those old textbooks and
look again. In the past, most sound
power measurements on musical instruments were made at much greater
distances than are currently used in
modern multi -channel recording. The
closer you get with the mic the higher
194
2.026,500 miclor.a.
1
184
Gunshot at one toot
Bass drum -hard beater
mIc inside drum
Snare drum played hard.
m1c at 6
174
164
154
140
134
Grand piano. ten tinger
full chord played
as hard as possible,
mrc inside case with
lid on short post
16
Operatic tenor
wrock singer
ih plc on lips
at tali volume
Isereamt
144
inches
strings forte.
110 feet from
124
-
114
Cymbal crash, mic at 6 in.
Fender Deluxe, all
controls at 10, mio
10 Inches from speaker
104
mic
section
10
Acoustic guitar
layed with the lingers,
at 12 inches
from top
=
1
newton
Standard lest for mics
94 and 74 dB SPL
Bd
1
0
dB sPL
microbar = 0.1 newton
per square meter =
per em'
74
1
dyne
.0002 microbar .0002 dyne/cm,
2 x 10" newtons per
square meter
2
2
32
microbe,
per square meter = 10 dynes
per cm'
French Horn (one)
Ic at 10 feet
x 10' microbe,
x 1P' dynes/cm'
the SPL gets, and ten feet just don't
hook it these days on a snare drum. At
this point you might say, "But these
levels are above the threshold of pain."
Right. Stick your head in front of that
acoustic guitar if you want to hear
what you're going to get, but don't put
your head inside the bass drum. The
drummer might give it a good sock and
make you deaf for a week! Take care.
It's also obvious that you don't have
to play a snare drum with a tire iron. A
little less vigor means a lower SPL and
perhaps a little less trouble for sensitive mics.
Standard References
On this sound power chart you will
find a couple of reference points that
are not music. 94 dB SPL, which is 10
microbars, 10 dynes per centimeter
squared and also 1 newton per square
meter. All three of these reference
numbers will produce a 94 dB SPL
figure when plugged into the formula
for finding a ratio in dB along with
their respective "zero sound pressure"
numbers at the bottom of the chart.
(DB SPL =20 Log,O en , where
P= pressure change you want to convert to dB SPL.
If you use the formulas with the
smaller values found at the 74 dB
point you should get "74 dB" as a
result. The formula is constant, only
"P" (the pressure change value) shifts.
These two points are the standard
reference for sound pressure used in
testing mics. Ninety -nine times out of
one hundred you will find the 94 dB
sound pressure used, but to be dead
sure we have given you everything, we
must mention the lower value as well.
Here's how it works. You stick the mic
to be measured into a sound field of 10
dynes per square centimeter (10 micro bar, 1 newton per square meter, they're
all the same), call it 94 dB SPL if you
like. Then you measure the voltage
that comes out of the mic. This
number, gets plugged into the dB formula with one change. The reference
that you are comparing the microphone against is now dBm. Since the
voltage the mic produces at 94 dB
sound pressure is lower than "O
dBm," you get a minus number. For a
KM84 Neumann it says on line "E,"
that for a 10 dyne per centimeter
squared sound pressure (94 dB SPL)
the mic will produce an output of -38
dBm. The relationship between SPL in
and dBm out is linear in dB. In other
words, raise the sound power, or vol-
Alexander Graham Bell
and the mic will put out 10
dB more, up to its electronic limit of
133 dB. That figure is line "L" on the
spec sheet. For 133 dB sound in, you
urne, 10 dB
get +1 dBm out.
Did we lose you? Okay, once
more, real slow.
94 dB SPL in = -38 dBm out
104 dB SPL in = -28 dBm out
114 dB SPL in = -18 dBm out
124 dB SPL in =
8 dBm out
and at clip, 133 dB SPL in = +1 dBm
output from the mic.
Once you have a sensitivity figure in
dBm you can usually figure out what
you need to know about almost any
type or style of mic. Most mic companies give the sensitivity conversion
using a 94 dB SPL source noise even if
they don't list all the references. Condenser, or powered mics usually run
from about -50 dBm to -38 dBm or
so. Most dynamics (Shure, ElectroVoice, AKG) run from a low of -60
dBm to a high of -52 dBm. It's also
useful to know that the overload or
clip point for most dynamic mics is so
high that most manufacturers don't
even bother to list it. A recent Senn heiser ad for the MD 421 showed its
undistorted response to a pistol shot.
Back to the SPL chart again. 178 dB
SPL! And still going! Dynamic mics
also create very little noise -no active
electronics at all, so no big noise
figures. Their actual noise measurements run pretty close to the theoretical limit, which is just the movement due to heat of electrons in the
voice coil.
This is beginning to sound like an
ocean of praise for dynamic mics, so we
better say something to set you
-
MODERN RECORDING
SELECT
DOLBY NR
TA
EO
C
/DIN
LINE
Long life Sen -Alloy head
'mproves performance
reduces distortion.
peak level indicators help
eliminate distortion.
5 LED
.
Automatic recording
when you're not there.
CI
i
a
ON
OFF
Dolby reduces tape hiss.
Bias and ED switches for all
types of tape.
No cassette deck can give
you better performance
without all these recording
ingredients_
,alr
a`
KD -35
L
JVC
STEREO CASSETTE DECK
COUNTER
,pAA
Loalr.s
.
MIC
INPUT LEVEL
INPUT SELECT DOLBY NR
SAS
EQ
PHONES
OUTPUT LEVEL
TAPE SELECT
PAUSE
REWIND
.0C /DM
)t
INE
1
Off
i
_
f
- C.
NCNM /Sf
1
1
ER
se
combines the truly sensitive
performance of permalloy with
Most quality cassette decks look
pretty much alike on the outside.
So at first glance you might take
the new JVC KD -35 for granted.
But take a second look.
You'll see something no other
make of cassette deck has -five
peak- reading LED indicators.
With a faster response than VU
meters, or even peak- indicating
meters, they help you avoid
under -recording and they
eliminate tape saturation and
distortion. It's as close as you can
come to goof -proof recording.
Then there's JVC's exclusive
Sen -Alloy head for record and
playback. Designed to give
you the best of two worlds, it
'Approximate retad valve.
PO
the ultra long life of ferrite.
Of course, the KD -35 has
many other features like Dolby,
bias and equalization switches,
and automatic tape -end stop
in all modes. It's also possible
to go from one operating mode
to another without going through
Stop. What's more, you'll never
have to miss taping a favorite
broadcast because you're not
Dolby is a trademark of Dolby Labs. nc
;
We build in what the others
leave out
CIRCLE 43 ON READER SERVICE CARD
there; just connect the KD -35 to
a timer and switch to automatic
record.
And yet, with all this built -in
capability, at $260,* the KD -35
is priced just above the least
expensive model in JVC's new
cassette deck lineup. Just
imagine what our top model
is like.
JVC America Company,
Division of US JVC Corp., 58 -75
Queens Midtown Expressway,
Maspeth, New York 11378
(212) 476 -8300. For nearest JVC
dealer call toll -free (outside N.Y.)
800 -221 -7502. Canada: JVC
Electronics of Canada, Ltd.,
Scarborough, Ont.
straight. As good as a dynamic mic
can be, a good condenser or powered
mic is usually better. How? Transient
response primarily. The moving parts
of a condensor mic weigh much less
than the moving parts of a dynamic
mic. They can respond to impulses and
fine detail in complex sound much
more rapidly and accurately. If you
can afford them. (They usually cost
anywhere from two to ten times as
much as good dynamics.) We highly
recommend the purchase of a pair.
Good microphones are the key to
really good sound.
A final look at the spec sheet for the
KM84 will show you that most of the
numbers we haven't dealt with directly are obtained by adding or subtracting one line to or from another.
The signal to noise figure is found by
subtracting line "H" from the reference pressure -94 dB SPL -18 = 76.
The dynamic range on line "M" is
found by subtracting line "H" from
line "L" -133 dB -18 = 115 dB.
IEC and DIN
Now about line "H," what's "A"
weighting anyway? Well, you could
call this a legal form of cheating. The
human ear does not hear low level
sound with the same frequency response as it does higher levels. The effect becomes quite pronounced as you
approach that .0002 microbar limit, so
simple and the pattern, or directivity
(cardioid) is fairly well understood by
now, so it's safe to say we have
covered just about everything of interest. By this time you may think we
have lost sight of of Ma Bell, but
that's not so. Where did that reference
of 94 dB SPL come from? It just happens to be the average power of human
speech at two inches. Telephones have
mics in them, remember? Ma Bell is
the International Electrotechnical
Committee (IEC) allows you to disregard low bass and high treble noise
when you prepare a signal to noise
figure. The "curve" is the human ear
sensitivity curve turned upside down.
This lowers the total noise energy by
quite a lot, but the reasoning is probably valid. You probably can't hear it
very well, so why worry about it. Now
the Germans are a little fussier about
this, so on line "I" they have a more
rigid standard with a much flatter
weighting curve defined by the
Deutsche Industrie Normen (DIN)
specification number 45405. Result?
More dB of noise. If you want to read
exact systems for IEC 179 or
DIN45405 you will need the Berlitz
crash course we talked about at the
beginning of all this. The IEC paper is
in French and the DIN standard is
written in German.
Well, that's just about all the specs
on the sheet. The frequency response is
Let's talk
about the
without a doubt the world's largest
user and tester of microphones and has
been in the mic business longer than
anybody else.
Once you have converted the sound
power of your music to dBm it's not
too difficult to apply the numbers to
your mixer specifications and discover
things like, "How much amplification
will I need to get it on the tape ?" or
"What's the maximum dBm I can plug
into the mic preamp without creating
distortion?"
The better mixer companies will give
you a continuation of dB numbers to
keep this process going and produce
more useful information about the
process of recording. This article won't
solve all your problems or make every
tape perfect, but we hope it helps.
4
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-
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Pedal control of phasing rate.
Manual phasing like a wah wah.
Three additional controls that
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CIRCLE 47 ON READER SERVICE CARD
34
MODERN RECORDING
WHAT COMPANY MAKES THE MOST EFFICIENT
P.A. AND DISCO SYSTEMS UNDER $5003
hYRONG,
usTrrsacoK!
Introducing the Acoustic 806 and 807, two new speaker designs for
maximum performance at a very modest price. Both are three way systems
that cover the audio range with incredible efficiency. And efficiency means
more dollars in your pocket since they don't require a monster amplifier
to get the sound out. Visit your nearest Acoustic dealer, and compare the 806
and 807 to whatever you thought was the best. You'll be pleasantly
surprised. Now check the price tags. When we said "Under $500," we meant
"WAY UNDER $500." From Acoustic... the surprising company.
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high fidelity components
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CIRCLE 26 ON READER SERVICE CARD
Murray Krugman and I sat at an old
picnic table on the tar and gravel roof
of the Record Plant, New York, discussing his introduction to Blue
Oyster Cult. He explained how in 1970
he had been in the marketing department at Columbia Records and had
decided that he no longer wanted to
take finished product and run with it.
Instead he wanted himself to be involved with making the product. He
began looking for a completely unknown group to take into the studio.
He shook his shaggy head as he
spoke about finding a group to produce: "I had done a 'live' Johnny
Winter recording, John Dawson
Winter III, when Clive Davis sent me
a tape of this group, The Soft White
Underbelly. I had no interest in them.
A short while later he sent me another
tape of a group called Stark Forest
more or less the same group with a
couple of new players -but I had no interest in them either, though they had
quite a cult following in New York.
"A few months later I was at a Log gins and Messina press party when
this guy Sandy Pearlman walked up
and said, `You're the guy who passed
on my group twice! The Soft White
Underbelly and Stark Forest.... How
come you passed?' It sounded like
lame acid stuff, you know, east coast west coast. 'I'm really looking for an
American Black Sabbath.' His eyes lit
up and he said, 'Well I've got it -come
hear us!' I didn't believe him of course,
but I went and I heard enough good
material to say, 'Yeah, if they do
everything right they could happen ..
with a whole lot of luck.' "
-
.
Raw Sound
The luck stayed with Blue Oyster
Cult. They did the first album with
Murray and David Lucas at his Warehouse Studio, and are now working on
their sixth album for Columbia with
Murray, David, Sandy Pearlman their
manager, and behind the console,
Record Plant's Shelly Yakus.
BOC is Allen Lanier on keyboards:
Albert
Bouchard,
drums;
Don
Roesser, guitars; Joe Bouchard, bass;
Eric Bloom, guitars and vocals; and to
quote Murray, "They are all very different personally and professionally."
They have been together for about
seven years, on the road and off, and
although commercially they cannot be
termed a "monster" group they have
managed to maintain a fairly stable
36
group relationship as well as stay on
the charts. Their fans call them
"Heavy Metal, Man!" and they have a
rather loud and elaborate laser light
show, but their producers are material conscious. Most of their albums (Blue
Oyster Cult, Tyranny and Mutation,
Secret Treaties, Agents of Fortune)
have been conceptual and thematic
speaking out against the evils of the
environment and society. The only
"live" album, On Your Feet or On
Your Knees is a good example of that
raw, heavy metal "live" sound.
-
Broad Spectrum
The latest album is being done
piecemeal fashion -in between road
tours. Six songs have been recorded,
three are finished with overdubs and
one has been mixed. The material
again is of great importance. The
group and producers are leaning a bit
toward that ugly word "commercialism," but with seemingly fine
results, and they are looking for a
more polished sound than in previous
works.
"The album comes across as very
diverse, which most people think is an
asset," Krugman said, "but when you
have five people writing material, each
in a totally different universe ... well
... none of the songs appear as if they
shouldn't be on the album, but it's a
broad spectrum. The only thing that I
avoid is music that has no artistic
value ... but we are looking for a hit."
On this project there are three
(count them) producers: Krugman,
Lucas and Pearlman, and one engineer
who "produces his end of it," Yakus.
Murray explained the breakdown of
responsibilities: "Shelly is instrumental in getting the sound on the record
as is Sandy in the mix; David is instrumental in the performance of the
group -he conducts the sessions in the
studio; I concentrate more on the ar-
rangements."
Actually this album is a real coproduction. It breaks down into the
song. When one producer is stuck for
an idea another usually comes up with
something that they all, the group included, can agree upon. Although
there are times when it is simpler to
avoid discussion. "When you have
eight or nine people in the room, sometimes it's easier to just tell someone to
do something and if it's great, fine. If
something has to be added or changed,
in that case I would rather do it later."
Krugman does respect, though, the
high sound standards of the individuals in BOC. "About four years ago we
insisted that they all have top quality.
four -track home systems. As a result
their standards and ours went way up
so that now only the highest quality
recording is acceptable."
Studio "C"
"Going Through The Motions" is a
stirring four -section rocker that
Krugman describes as "sort of rock
and roll pop." The sessions for "Motions" took place in Studio C at the
Record Plant with Yakus engineering
and Thom Panunzio assisting. Murray
likes to work at this particular studio
for a variety of reasons: He lives in
NYC and hates to travel to work, he
likes the reasonable and cooperative
attitude that prevails, the maintenance staff impresses him and "though
I can't talk numbers the way engineers
can, I know that the top -end spectrum
[of the studio] gives me anything I
want."
The basic equipment in "C" is as
follows: A Datamix console that has
MODERN RECORDING
been customized by the maintenance
and engineering staffs to accomodate
the needs and whims of the clients. It
has the availability of thirty inputs
with the possibility of thirty to fifty
positions out. There is an MCI multitrack and an Ampex 440 Electronics
two -track with an A300 Deck. The outboard equalizers are Pultec; the phaser
and digital delays are Eventide and
the system includes Pye, Teletronics
and Fairchild limiters. The monitors in
"C" are Hidley Monitors, but Yakus
likes to play back on KLH 6's.
"They're a little warm or "dull"
sounding and they don't play back the
real high top. That's good because it
takes off a lot of edges and you really
hear if you have the meat of the mix.
They show me if my relationships are
SEPTEMBER 1977
in the right place. If something is hardly there when I listen back, that means
it's gone -which makes me go for the
higher frequencies."
MIC
Recording Expertise
Shelly has worked with Blue Oyster
Cult and its producers for a few years
Chart
Piano -Sennheiser 421 -Low strings Bass Amp -Shure 57
Direct
-Top
Neumann U87
Organ
Leslie
Neumann U47 -FET -Top
Bottom
Shure 57
Guitar
Amps
Sony C38
Shure 57
Neumann U87
-
-2
Neumann U87s
Drums -Tom Toms
Snare -Shure 57
High Hat -Shure 57
Bass Drum -Shure 57
Vocal- Neumann 47
(old type)
Neumann U87
37
-
and appreciates their musicianship
"In recording a group like this we try
to make them forget they're in the
studio and give them a "live" feeling.
But on this album we are also trying
for a more finished sound."
In reaching for this "live" but finished sound Yakus starts recording at
30 ips which gives a better signal -tonoise ratio. He feels it is a lot more
alive sounding and captures the excitement from the room, and as he is not
using Dolby, there will be less tape
hiss and a broader high- frequency response. "The bottom response is better at 71/2 or 15, but our multi -track
machine leaves us no problem there."
He is not using Dolby because "with
the high levels we put on tape it's not
Blue Oyster Cult: (Left to right) Joe Bouchard, Eric Bloom, Don Roesser,
Albert Bouchard and Allen Lanier.
(ALBERT)
DRUM BOOTH
FTO
S
FTOOO ÖQHH
I
HAMMOND
ORGAN (ALAN)
GUITAR AMPS
ST
ST
(DON)
I
BASS AMP
(JOE)
GUITAR
AMP (ERIC)
PIANO (ALAN)
VOCAL
CONDUCTOR
DAVID LUCAS
iJ.wuuuuuI
CONTROL ROOM WINDOW
ORGAN
LESLIE
VOCAL
BOOTH
38
STUDIO "C"
MODERN RECORDING
necessary." He feels it kills some of the
excitement at the high end and is
rather sterile for the purposes of BOC.
However, if the same group were doing
something quiet with a great deal of
dynamics Shelly would then use
Dolby.
Another technique this engineer
relies upon for that polished sound is
the use of Kepexes. On the tune "Motions" they are used to keep down the
noise level between guitar solos, prevent too much leakage onto the bass
drum track, and where a particular
problem came up with a vocal:
"There was a very slight problem
with noise during the recording of a
lead vocal. Rather than stop the performance we put a Kepex on the track
during the mix."
However, Shelly tries not to compensate at the board too much during
recording. He uses digital delays to
thicken, and equalizes the echo
chambers in a way he says is unusual
and difficult to explain because it's
done by "feel."
"Cult" guitarist Eric Bloom taking a little time out.
Producer Murray Krugman (left) and keyboardist Allen Lanier.
SEPTEMBER 1977
39
Guitarists Don "Buck Dharma" Roesser (left) and Eric Bloom.
During the basic tracks Murray,
Sandy and Shelly found themselves
out in the studio listening, especially
when it came to mitring. "If the mic
placement doesn't sound good in the
studio then it's not going to work well
at the console," Shelly said. He trusts
his BOC mic combinations for the
most part although he will go into the
studio for the drums at the beginning
of the session. In a time when most
engineers get caught up in an overabundance of drum mics, Shelly uses
as few as possible; five in all on
Albert's drum kit. They will work on
the balance together to find the room
sound first. "I like the drums to ring
as much as possible without hanging
over into the next beat. I like a full
tom -tom sound -if you deaden the
drums a lot they don't speak ... they
have to be responsive because this
music swallows up so much of the ring
anyway. So we tune them so they'll
ring like crazy." And then he puts
them on seven tracks, two of which are
stereo drums, comprised of all of the
mics except the bass drum. In this way
Shelly uses the combined sound during
the mix adding bass drum, snare and
toms when needed. Again here he feels
he is going for a more finished sound.
On bass, Joe Bouchard played both
with his fingers and guitar picks in
"Motions." Consequently, Shelly
miked the bass amp as well as taking it
directly through the board. "We miked
the bass amp looking for something interesting. On this song we almost used
the mic track completely, but when we
gave it more bottom end it became
mushy. The direct track had more
solid bottom so we went back to it but
added a little of the mic track for top."
Basic Perfection
The recording sessions were a
straight -ahead combination of talent
and work. As BOC is self-contained
there were very few extras on the
tracks: a phased string synthesizer for
a realistic string sound, doubled vocals
for strength, some dazzling extra
guitar work peppered throughout; but
the sound remains exciting and basic,
the tracks and musicianship sophisticated and competitive.
In mixing these tracks Shelly took
the time needed. He is not a "quick
mix" theorist and believes that taking
two to three days for one long tune is
ideal although not always acceptable.
Murray and Sandy like to mix for a
day, leave the tune overnight and
come back fresh the next day.
"Sometimes magic happens by accident," Yakus explained, "but I like to
feel I'm going for it [the magic] when
I'm going for it. Once you get one
thing to sound great you must get the
rest sounding great. Of course, there's
only so much time you can spend .. .
but Blue Oyster Cult mixes need a lot
of attention."
Shelly played the finished mix of
"Going Through The Motions." I liked
it fine ... it was moving and exciting,
"live" sounding yet very polished.
"Yeah," he said wrinkling his brow,
"but it could use more bass."
Well, perfection is never an easy
thing to find.
Our amp had a few rough critics to
please. Moog. Gibson. Les Paul.
Ronnie Montrose. Our
oscilloscopes. And you.
Nobody knows everything there is to
know about amplifiers. The Lab Series
engineers were ready to admit it...
and do something about it. We went
to several outstanding audio experts.
And they helped us put more good
ideas into the Lab Series than any one
company could ever think of.
When you're making a guitar amp,
it helps to work with an expert on
guitars. So, the Lab Series engineers
studied with the world's foremost experts- Gibson." And we learned the
nuts and bolts, from humbucking
pickups to "f" hole acoustics.
As for musical electronics, there's
no better place to go than Moog :" So
that's where we went. And we studied
with the people who have an ingenious
reputation for putting electronics
under the musician's control.
of your guitar. Sustain notes that swell
Advancing an amplifier takes adas you hold them. Vary your picking
vanced technology- something that
attack from a punchy delivery that extoday's amplifiers haven't really enplodes off your pick, to a smooth,
joyed. For example, the Lab Series
even flowing performance. The Multi engineers applied new advancements
filter control rein high voltage
arranges the
transistor techhigh harmonics
nology that let
to add an acousus overcome the
tic guitar flavor.
problems of low
And get rid of
voltage transisthose transient
tors. And that
peaks of over enabled us to
load that send
Uncompressed sound (left) vs.
create the exact
Compressed sound. Note difference
recording meters
sound our musiin loudness and time relationships.
into the red.
cian advisors
But technology doesn't mean much
were after. But technology has a lot
if an amp can't take the punishment
more to offer. After all, if Moog can
of the road. Lab Series amps are
engineer an orchestra of sounds into
rugged, reliable and lightweight. With
a small, 20 lb. keyboard, we felt an
pine sides that fingerlock at each
amplifier should offer more control
corner. Eight steel corner caps. An
over its voicing. Our new circuits overoversize heat sink.
came basic amp shortcomings. For
Even 8- teenuts
example, if you like the overtones
you get when you overdrive your amp,
chances are you like your sound at
high volume levels. But if the room is
small, you're either too loud, or too
lackluster. The Lab Series Compressor
lets you sound great at any volume
holding each
level, so you can turn on intense overspeaker, instead of theme
driving distortion without overpowerusual four.
ing the room. You can even equalize
We put a lot of thought into the Lab
your sound to help overcome poor
Series. And so did a lot of other
room acoustics.
people. The result is an amp that
What's more, we engineered several
pleases the critics, like you and your
outstanding sounds into the Lab
audience.
Series. The Frequency and Midrange
And that's why there are only two
controls let you tune into different
types of amps today...the old ones,
frequency bands and tone colors the
and the new one -the Lab Series.
same way you tune in stations on
your radio. It also lets you overdrive
sections of a chord, so you can create
new chord colors that really expand
your rhythm horizons.
There's more, including some guitar
tricks Gibson helped develop. The
Lab Series lets you match the voicing
"
Then we put the Lab Series amplifiers through some heavy studio
sessions. And set out to please some
heavy artists, like Les Paul and
Ronnie Montrose.
Next, we took it to the streets to
talk to our most important critics
the people we really built the Lab
Series for -working musicians.
And for two years, we kept asking
for criticism, until all we got were
-
compliments.
7373 N. Cicero Avenue, Lincolnwood, Illinois 60646
51 Nantucket Blvd., Scarborough, Ontario, Canada
Write for free Lab Series brochure.
CIRCLE 73 ON READER SERVICE CARD
THE NEW
GENERATION OF
RECORDING
INSTRUMENTS IS
AVAILABLE AT THESE
TASCAM DEALERS:
ALABAMA
Birmingham
Sonics Associates Inc.
Gadsden
Roy Grantlands Sound World
ALASKA
Anchorage
Team Electronics
Juneau
Alaska Music Supply
ARIZONA
Phoenix
Bruces World of Sound
Tangent System
ARKANSAS
Fayetteville
Ace Music Center Inc.
Associates
World Electronics
Orlando
Discount Music Center Inc.
Pensacola
Grice Electronics Inc.
Tallahassee
Hi -Fi
Norton Music
Tallahassee Music Studio Inc.
Tampa
Audio Visual Services
MARYLAND
Elkton
Mars Piano & Organ
Timonium
Sound Factory
Wheaton
Washington Music
Chamblee
Pro Audio Atlanta
Tucker
B &
H Distributing
HAWAII
Honolulu
Audissey
Electronic Systems Inc.
Mountain View
Rain Recording
ILLINOIS
Roy Baumann Music
Everything Audio
Oakland
Leo's Music Inc.
Redwood City
Accurate Sound Company
Sacramento
Advance Sound &
Electronics Inc.
San Diego
Apex Music Co. Inc.
Pacific Recorders &
Engineer Corp.
San Francisco
Sound Genesis
San Jose
Alco Paramount
Electronic Corp.
Guitar Showcase
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Warehouse Sound Co. Inc.
San Rafael
Bananas At Large
Santa Barbara
Fancy Music
Torrance
Quantum Audio
Upland
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West Los Angeles
The Eighth Note
Arlington Heights
Chicago
Continental Music House
Midwest Enclosure
Midwest Sound
Sound Market Recording Co.
Cicero
D J Music Ltd.
Collinsville
Swing City Music
Marissa
Ye Olde Music Shop
Normal
Glenn Poor's Audio Video
Palos Hills
Gill Custom House Inc.
Pekin
Milam Audio
River Grove
BSC Inc.
Roselle
Roselle Music
Schaumburg
The Stereo Studio
Denver
DTR Sound Corporation
Sight & Sound Entr Inc.
Ann Arbor
Ann Arbor Music Mart
Detroit
Fiddlers Music Company
Farmington
Sound Patterns DXM
Rec. Studios
Grand Rapids
Audio Distributors Inc.
Morris
Boynton Studio Inc.
New York City
Harvey Sound Inc.
Lyric Hi Fi Inc.
Manny's Musical Instruments
and Accessories Corp.
Martin Audio/Video Corp.
Rensselaer
Cathedral Sound
Rochester
Maynards Sound World
The Sound Chamber Inc.
Roslyn, L. I.
Audio by Zimet Inc.
NORTH CAROLINA
Burlington
Don's Music City
Charlotte
Reliable Music
Sounds Impressive
Greensboro
Audio Unlimited of
No. America
Raleigh
Sound Ideas
Winston -Salem
Long Engineering Corp.
Jackson
Jackson Music Mart
Kalamazoo
Sound Room
Livonia
OHIO
Akron
Audio Hall
Chillicothe
Audioland
Mt. Clemens
Appalachia Sound
Audio Land Men of Music Inc.
Swallens Inc.
Columbus
Custom Stereo Electronics Inc.
Palmer Stereo Center
MINNESOTA
Minneapolis
Audio King, Inc.
AVC Systems, Inc.
Moorhead
Marguerite's Music
MISSISSIPPI
Jackson
Sound
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MISSOURI
Kansas City
Cincinnati
Sound Advocate Inc.
Dayton
Dayton Communications Corp.
Niles
United Electronics
Parma
Winter Radio Inc.
Youngstown
New York Music
United Electronics
SOUTH CAROLINA
Columbia
Pecknel Music Co.
Florence
Whitestone Inc.
Greenville
Peclmel Music Co.
SOUTH DAKOTA
Sioux Falls
U A
Recording
TENNESSEE
Bristol
Joe Morrell Music Co.
Chattanooga
Music Mart
Memphis
Strings & Things
Nashville
Audio Systems Inc.
Hi Fi Corner Inc.
Nashville Studio System
TEXAS
Amarillo
Billy's Band -Aid
Dallas
Recorder Center
El Paso
Casa Sonido, Inc.
Garland
Arnold & Morgan Music Co.
Houston
Sound West of Texas
Irving
Audio Video Designs
Odessa
Electronic Service Centers
Richardson
Collins Radio
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UTAH
Ogden
The Hi Fi Shop
Salt Lake City
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VIRGINIA
Norfolk
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Music & Sound
WASHINGTON
OKLAHOMA
Oklahoma City
Bellingham
Ford Audio & Accoustics Inc.
Stillwater
Stillwater Music Center
Tulsa
Ford Audio
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Electricraft Stereo Centersinc
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Joe Farmer Music Inc.
Spokane
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Wenatchee
Belmont Music Center Corp.
IOWA
Des Moines
NEVADA
OREGON
Oregon City
WEST VIRGINIA
'Iliad Productions, Inc.
Victor's House of Music
Iowa City
Advanced Audio
Engineering Inc.
Commercial Sound Studios
Electronic Control Co. Inc.
Portland
Rex Recording Co.
NEW JERSEY
PENNSYLVANIA
KANSAS
Hayes Music Company
Lawrence
Innovative Electronics
Overland Park
David Beatty Stereo
Wichita
Stamford
KENTUCKY
Audiotechniques Inc.
DISTRICT OF COLUMBIA
Covington
American Sound &
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Washington
Shrader Sound Inc.
Hi Fi
Modern Music
Jacksonville
Stereo Systems Inc.
Miami
MICHIGAN
Ithaca
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South Bend
Audio Specialists
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Omaha
Seco Labs, Inc.
The Stereo Scene
CONNECTICUT
Berlin
Fred Locke Stereo
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Sales Center Inc.
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Lebow Labs Inc.
INDIANA
Hays
COLORADO
Portland
New England Music Co. Inc.
Atlanta
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Environmental Electronics
Medians
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GEORGIA
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United Sound Systems
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TASCAM SERIES
BYTEAC
THIS 1S WHERE TOMORROW'S
GREAT MUSIC LS CONING FROM.
We think musical
styles change
ie :ause musical
Talents change.
There is hardly a
musician making
money today who
doesn't know as
much about
recording music as
he does about
playing it And
recordists know as
much about playing
music as they do
about recording it.
.
Because both know
the equipment that
captures music can
also be used to
improve it.
(©TEAC 1977
So while musical
styles may change,
the interdependence
of musician, recordist,
and the instruments
they use will not.
And that is the
reason for the
TASCAM Series by
TEAC.
For not very much
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lets both musician
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mixers and recorder/
reproducers that let
both tailor their
music their way.
The Model 5 -EX shown with four
Model 201 input modules.
Model 5 shown with Model 204
talk back/slate modules.
For every lend of
music, for every
kind cf need, at
home and on
the road, by price
has the same goal
as everything you
make -be the best.
Because
it still
takes
great talent to make
and application,
every-hing we make great music.
TASCAM SERIES
BY
T EAC®
A new generation of recording instruments
for a new generation of recording artists.
TEAC Corporation
Amer_ca
ì
Montebello, California 90643
o_
7733 Te_egrap Road
Canaca TEAC is distributed by White
Electron': Development Corporation
In
(1966) Ltd.
From Tape To Disc
Disc Mastering Part n
Last month we painted a rather dark
picture of the record mastering
process -which is understandable,
since to begin with most records are
black. However, as we shall soon see,
there is a bright side to all of this.
Just a quick review of last month.
We mentioned the space limitations
(both lateral and vertical) on records,
and tracing distortion (the round peg
in the triangular hole), which tends to
have an adverse effect on the high frequency information. We briefly discussed how to get two signals out of
one groove. You'll just have to take
my word for it that it works pretty
well, since an in -depth discussion of
that aspect of groove geometry easily
would fill the next dozen issues of MR.
that it (the playback
stylus) tends to be pinched out of the
groove. Thus it either "chatters"
through the section (too much high frequency information), or there is a
slight vertical aberration with lowerfrequency information. The latter example is rarely noticeable, while the
first type is the most annoying.
Tracking error on the other hand is a
did. The effect is
Photomicrographs (clockwise from left).
Fig.1: (A) Lateral modulation -100
Hz sine wave.
Fig.2: (B) Lateral modulation; 10
kHz sine wave (in- phase).
(C) Vertical modulation; 1
kHz sine wave (out -of- phase); (D)
Right channel modulation (no left
channel modulation; (E) Left channel modulation (no right channel
modulation).
Fig.3:
Fig.4: (F) Lateral sine wave modu(1 kHz); (G) No modulation;
(H) 300 -400 Hz sine wave.
lation
Photos by David Moyssiadis
Courtesy of Frankford(Wayne Mastering Labs, Phil.,
Pa.
By Dave Moyssiadis
Also, we talked about making tradeoffs and compromises in order to get
the things we want. In disc work, that
is what it really boils down to- either
having your cake or eating it; or having some of your cake and eating some
of it. From the mastering standpoint
having the cake isn't really necessary- just eating it is. I promise I'll
explain that soon.
Tracing and Tracking
We promised [last issue] to explain
the difference between tracing and
tracking errors. As you know, tracing
distortion is the inability of the
playback stylus to fit into the groove
in the same manner the record stylus
on the whole record where the playback stylus lines up with or tracks the
recording stylus. The rest of the time
the playback stylus is cocked in the
groove. This results in another cause
of distortion.
result of trying to make a pivoted tone
arm keep the cartridge on a tangent
with the record groove. The recording
lathe travels across the disc on a
perfect tangent in a straight line. We
are all familiar with how the record
player tries to do it. With a straight
arm there is only one point at which
this tangency is achieved. With a bent
arm we still can find only two points
We have all played a record and
heard the first notes before the record
actually began. This is called "pre echo" or "groove- echo." It is similar or
rather analogous to print -through on
tape. It starts in the mastering stage
where the grooves are too close together, and the problem is compounded in
the plating and pressing stages. The
only known way to effectively reduce
this is to spread the grooves apart at
the beginning and end of each song
where it is most apparent. And as with
-
most things, different types of program material are affected differently.
Piano, with its incredibly high peak attack, usually is the most troublesome
in both mediums.
Diameter Losses
Diameter losses are what happen to
the high- frequency response as the
record gets in closer to the inner diameters. On some records you may notice
that if you play the first cut and then
skip to the last cut (similar material)
there will be a noticeable drop in the
treble, almost as if you turned your
treble control down a bit. The reason
for this is that the groove is traveling
much slower near the label area than it
is at the beginning of the record. As a
matter of fact, the first revolution of
the recording is traveling slightly over
twenty inches per second, but by the
time you get to the innermost permissable groove on an LP, because of the
smaller diameter, the groove is only
moving at about 8.3 inches per second.
Similar velocities for a seven -inch 45
RPM record are 15.6 ips at the outermost groove of recorded program and
10 ips at the innermost recorded
groove. For the benefit of any walking
computers out there who have noted
the discrepancy between the 45 and LP
inner diameters, it is a little -known
fact that a 45 record goes in about half
an inch closer to the center on diameter (1/4 -inch closer radius) than the 12inch LP. You people with sharp eyes
will note that a 45 label is smaller than
an LP label. the LP label is four inches
in diameter and the 45 label is correspondingly less. But what we do about
the inner diameter losses?
Years ago when it was a miracle if
any highs got on a disc to begin with,
there was an automatic compensation
made. This simply consisted of an
equalizer mechanically linked to the
lathe carriage which turned up the
high-frequency response 2 -4 dB as the
carriage moved in toward the center of
the disc. Years later as technology improved and it was taken for granted
that highs could easily be put on the
disc, disc people were so pleased with
themselves that the compensating
device was eliminated from lathe
design (perhaps in over -compensation
of technology). Today there is a more
realistic approach appearing as more
knowledgeable mastering engineers
will include such compensation in their
over -all "artistic" approach. There is
,SEPTEMBER 1977
another easier method: we close our
eyes and pretend it isn't there, and
99% of the time it isn't even noticed.
The reason we no longer compensate
becomes obvious as you think about it.
If the oval stylus is too large to fit into
the notch made by the chisel- shaped
record stylus, it does little good to
make the notch any deeper. If you
can't get your finger into a small hole
in a wall it doesn't help to make the
hole deeper. This is directly analogous
to tape. Once you pass the point of
tape saturation with high frequencies,
adding more treble only leads to more
problems. Again, with disc, a lot of
this is dependent on program material.
On certain program content where the
original high- frequency information is
minimal it is possible to compensate
and effectively boost highs on the inner diameters.
Blood On the Tracks
Now to the nitty -gritty. You've got
this tape. You've placed an order for a
few thousand records. You get the
records. But ... the records don't
sound anything like your original tape.
The bass isn't there, the cymbals
sound like trash can lids, the record
sounds muffled. It's not nearly so loud
as Elton John's latest and it's as noisy
and scratchy as a bag of kitty litter.
Immediately you run back to the record plant with blood in your eye demanding an explanation from the manager. He matter -of- factly says that it
is not his fault, he can't help what the
plating company did. Furious, you
grab the nearest blunt instrument and
head for the plating plant, where the
manager there says you can't blame
him, it's all in the mastering. This time
you take out a firearm permit and a
hunting license, and blast your way
into your friendly neighborhood disc
mastering place. There you hear that
all those scratchy sounds are the fault
of the pressing plant. But, you still
have the business end of a shotgun
resting on the bridge of the mastering
engineer's nose. What about the bass?
What about the cymbals? What about
the level? Calmly, he explains why all
those problems occurred. Just as you
have read in these two issues.
Specifically, in order to keep the
record from turning white on the first
playing a good deal of the treble had to
be rolled off (all because of the too-loud
cymbals). That's why the whole record
sounded muddy. Don't forget, what
ever you do to correct one thing on the
tape happens to everything else on the
tape. It is not, repeat not, possible to
remix a master tape in the mastering
stage. The old, worn -out, procrastination- inspired cop-out "we'll fix it in the
mix" has degenerated into passing the
buck with the phrase, "Don't worry
about it, that can be taken care of in
mastering." Wrong! The only way to
take care of something in mastering is
to nearly annihilate everything else. If
the cymbals are too loud they can't be
lowered without lowering all of the
high end. If the vocals are too low they
can't be brought out. Sometimes we
can cheat with the equalizers and make
apparent changes, but again, not only
will the vocals sound a bit louder but
so will everything else in that range,
such as the guitars, etc. In addition,
the bass and bass drum will change
character.
The bass was not predominant on
your record because there was too
much "mud" in it. This caused too
much lateral excursion (using up too
much room), so that had to be altered
accordingly. Finally, the level was so
low because the record was very long.
A simple trade of level for time had to
be made. But the surface noise probably did come from the pressing.
Avoiding Trouble
Needless to say, the above episode
was an extreme case. But these things
do happen, although hopefully, not all
at once. So what do you do to avoid
any of the above? Simple. Take a
course in accounting and go for your
CPA. On the other hand, if you are a
masochist like the rest of us.... First,
choose a reputable studio that has
been around for a while and has a staff
that has been around for enough time
to know that the concoction they mix
onto the tape will eventually have to
be crammed onto a disc. Or just be
sure your mix -down guy has his act
together, and you can relax.
If you're out there like a babe in the
woods and haven't the slightest idea of
what constitutes a good studio and/or
good engineer then you have to work
hard at it. Watch the guy like a hawk,
but try to respect his abilities. Make
sure your bass and bass drum are
clear, clean and well defined -not too
muddy. Don't try to get into the
building demolition business with your
low end. Try to keep all the low frequency stuff in the middle -dead
45
center -if at all possible. There are
records that have the bass off to one
side, but the people who have done
that sort of thing knew exactly what
they were doing (I presume) and took
certain precautions (and still gave the
mastering engineer nightmares). Besides, if you put the bass on one side
you only have one speaker pushing out
the bass. If you use the center, both
speakers are pumping it out and you
get just as much bottom but it's
cleaner because each speaker doesn't
have to work as hard. Remember, the
vast majority of power is expended in
the low end.
Keep sibilant sounds from being
recorded. If you have a vocalist that
could win a hissing contest with a
snake, proper mic selection can save
your life. Usually a velocity or ribbon
such as the old RCA 77 DX or the old
44s will prevent the damage, and also
smooth out a thin- sounding voice.
Once the esses get into the system it's
too late. The equipment has already
been pushed to the limit and if you can
save it at all you will have to do a fix
with a de- esser. Now isn't it easier to
stop it before it becomes a problem,
like at the microphone? Same goes for
cymbals, wind chimes, finger cymbals,
bell trees, etc. The thing to do is to just
keep things under control at the control panel. If the speakers sound like
razor blades and your ears start to
bleed, it's time to back off somewhat
on such instruments -mix them in at
judicious levels.
Keep your program balanced. In
other words, left and right should
sound balanced and read just about
equal on each meter. Avoid outlandish
peaks, and keep the level up. Master
lacquers are quiet, pressings are a different story. In general, if the mix is
good, sounds good and is a good balance chances are that there will be little trouble in the mastering stage. Be
sure everything is in phase. If some
mics are out of phase or the board wiring is out of phase it will wreak havoc
with the cutter head. If the above principles are adhered to you should expect
to get pressings which are readily recognizable as your work. If there is too
much bass (even though you want it
there) it will undoubtedly be removed
by the mastering engineer.
Sitting In
If you are still unsure of how well
your tape was recorded with regard to
46
disc transfer, sit in on your mastering
session. Time was when disc cutters
were a breed of back room introverts,
who went about their toils behind
closed doors -their very existence
unknown to the world. Tapes went off
someplace and magically thousands of
little, round, black plastic frisbees appeared. No longer. The disc-mastering
Helping Out
One thing that should be included
with all your tapes is a set of tones. If
the tape is Dolby encoded there first
should be a Dolby tone at Dolby level,
then there should be a 1 kHz tone at
the recorder's operating level to set
balance, following that should be a 10
Playback stylus (left) in groove of sufficient depth; playback stylus (right) in groove
of insufficient depth, where groove is unable to hold stylus.
process has been discovered. Now producers have one more chance to futz
around with their tape. For the privilege of harassing another technical person, you must of course pay. It often
will cost you more to kibitz with a
mastering engineer than it will to have
your masters cut. But it may well be
worth the expense to see exactly what
happens when your tape is transformed into record format. You also
get the instant gratification of being
able to shove a 14 -inch master blank
down the engineer's throat if he
doesn't do what you want. (This procedure is not recommended, since it is
difficult -if
not impossible -for
mastering engineers to work at peak
efficiency in that sort of condition.)
Nevertheless, once in a while it might
be nice to see and get to know the guy
who does your mastering work. That
way you will have a mutual understanding. He will know what your
preferences are and you will understand some of the problems that he
may encounter.
kHz tone for azimuth (even if your
recorder is out of alignment, the
mastering playback machine can be realigned to play back the way your
machine recorded it), then 100 Hz
and/or 50 Hz tones to see what the low
end is doing. These tones are important if you want to get the most out of
your tape. They should be put on the
tape immediately before the recording
is made, and on the same machine used
to record. If you forgot to put the
tones on and the machine settings
were since changed, don't bother. The
idea of the tones is to reflect what the
recorder was doing with its input. If
the recorder was out of alignment
when the recording was made, don't
adjust the tone afterwards to make
them look good or you'll defeat your
purpose. The tones are worth a handful
of valium to a mastering engineer.
You can also prevent your disc mastering engineer from heading for
the pills by properly preparing your
tape for disc transfer. A single should
have head and tail leaders at least five
MODERN RECORDING
Why do you think it's called public address?
The aucience is there to have a rood
time. You're there to work. But, if yoL're. not
projecting -he sound you've worked so
hard to perfect, you just wasted all those long
hours in rehearsal.
Now that you're increasing your public,
it's time to address yourself to an investment
in PA. Check out Yamaha's EM- Serieï of
affordable. fully- integrated sound reinforcement systems.
The EM-80, 100 and 150 integrated mixer
amplifiers. From four to six input cha,nels,
from 60- to 150 -watts RMS. Link them Together
for even greater flexibility. They're reliable
and roadable because they're buill'(amaha
tough.
Yamaha's unique stereo balance control
lets you op-imize sound levels in dif'erent
parts of a room. Practically any setup is
possible with combinations of micrrrphones
and electric instruments taken direct,
amplified and submixed.
When it comes to speakers, Yamaha has
two impressive models to choose from.
component is made by Yamaha to our
own exacting specifications.Yamaha's
super -efficient, two -way S4115H enclosures
with a horn - loaded 15" woofer, HF horn/
driver combination with level control, and
100 watts power handling, make perfect
Every
mains. On the other hand, our S0112T
enclosure with 10" and 12" woofers, four 2"
cone -type tweeters, and 80 watts power
handling, are ideal as stage monitors or
excellent low -cost house mains. Both
models have built -in passive crossovers,
and are available with built -in power amps.
For all the facts, send this ad along with
four dollars. (Please, certified check
or money order only. No cash or personal
checks.) We'll rush you an operation
manual complete with block diagrams on
our EM- Series. Or better yet, see your
Yamaha dealer and plug -in to an EM.
It may be for your audiences, but their
enjoyment is going
to pay off for you.
aRCLE 42 ON READER SERVICE CARD
YAMAHA
Musical Instrument Combo Division
6600 Orangethorpe Avenue. Buena Park, CA 90620
Write P O Box 6600. Buena Park, CA 90622
seconds long. An LP should have
about ten feet of leader at the head and
tail of each side and four seconds of
leader between each selection or wherever you want a band or spiral. This is
essential for the automatic equipment.
Again, don't forget the tones. A
Dolby- encoded tape must have a
Dolby tone at Dolby level or you can
forget quality.
Time vs. Level
Well, now a few short words about
length. Usually the first question is,
"How much time can I get on a record?" The answer is easy. How loud do
you want the record to be? See, isn't
that clever? I answered a question
with a question. No, I won't try to
avoid the problem. Here are some more
cold cruel facts about life in the
mastering world. If you want maximum levels with "acceptable" distortion figures, the average LP side
should not exceed eighteen minutes
and the corresponding figure for a 45
single would be about 3:30. This of
course to a large extent would depend
on program material. If the entire side
consists of bass and bass drum solos,
that time would be significantly reduced. On the other hand, if half of the
record is upper register harpsichord
you can get away with a few more min utes. "MacArthur Park" is the famous
seven minute plus record that has lots
of level -but only at the end. There is
no way that that particular record
could have been cut that loud if it were
as loud throughout as it was at the
end. It was accomplished by utilizing
Unmodulated record groove.
48
the variable pitch system, which will
be explained shortly.
But the question still hasn't been
answered. Actually, you can cut an LP
side as long as 45 minutes and still
have it track on the average record
player. Once, just for kicks, I put 60
minutes on one side. However, the
finest playback system today can just
barely track it. The 45 minutes by the
way would have to be silent grooves. If
you want to breath in the studio then
the time gets shorter. A practicle limit
for LPs is about 30 minutes, and even
then you are pushing it. If you go
much beyond that, about half the
record players in the country will set
down on the lead -in, skip right across
the record and up onto the label. As far
as 45s go, try to keep the time under
six minutes. Pass that and you start to
buy trouble in the form of a high
record returns rate. There are some
record players such as the "Nineteen
Ninety -Five Special" that won't track
anything, let alone a 35- minute LP
featuring Ludwig Von Leadfoote playing pipe organ. So to narrow it down, a
reasonably long LP with reasonable
level should be 18 -24 minutes, and a
single should be 4 -5 minutes. [Both
figures are per side.] Remember almost
anything can be put on a disc, if you insist. Your problems begin when you
try to get it off the pressing.
Creating Hot Problems
This brings us to the question of
"hot" levels and not so "hot" levels.
At the beginning of this article we said
modulation (sine wave);
monophonic or in -phase signal.
Lateral
that we couldn't have our cake and eat
it too, but, that we shouldn't want to
have it, we should just want to eat it.
First of all, present day state-of -theart equipment will permit +4 dB of
level on a 45 rpm single as a practicle
maximum limit with a reasonable degree of distortion (on an LP this limit
is 0 dB). Unfortunately it is hard to
relate to these figures as they are not
the same thing as tape levels. Tapes
are referred to nanowebers/meter and
the present range is 185 to about 250
nanowebers/meter to give a 0 dB output. That is a reference to magnetic
power. The range just mentioned is
about 3 dB. In disc parlance this translates into stylus velocity (not to be
confused with groove velocity) of
cm/sec. Current standards refer to 7
cm/sec. to give 0 dB. The older standard was 5 cm/sec., which was approximately 2 dB lower. So to make matters worse some companies still use
the old standard and claim that they
are cutting a record at +6 dB -which
would be lunacy at the new standard.
It is really +4 dB. Confused yet?
Well, the figure 7 cm/sec. simply
means that if the stylus were to travel
sideways (which it does), it would
move 7 cm every second. It does this
however by going from side to side and
reaches a peak velocity of 7 cm/sec.
These are only permissible standards.
The limitation is again in the playback
equipment. Present day cutter heads
actually can drive styli to peak velocities of 74 cm/sec., which is above
anything that can be played back. This
is actually corresponding to record
levels of +15 dB or better! No play-
Vertical modulation; out of phase
Left channel modulation only.
signal.
MODERN RECORDING
back system today can even begin to
track those kind of levels. But the real
question: why would any one want to?
Hot levels create unnecessary problems. In actual practice, when there is
difficulty with a particular record,
there are two ways to solve the problem. The first would be to adopt extraordinary measures such as rolling off
the bass, or the top, or squashing it
with a limiter, or to eliminate too much
vertical lift, bleeding the left and right
so much as to make the record almost
mono. The second solution, which
usually solves almost any problem, is
to drop the level by only 1 dB. In reality, 1 dB is almost unnoticeable! But
most people would prefer a night on
the rack rather than sacrifice that insignificant iota of level. Hot levels
bring you into distortion -not to mention the other problems-and cause
the record to wear much faster. It will
cost in cleanness too. Have you ever
noticed how a record-no matter how
old, worn and distorted it is- almost
always sounds cleaner and clearer on
the fade -out? That is an example of
what you could have if only there
wasn't this incessant demand for high
levels-both in the mix studio and the
cutting room. First of all, it does absolutely no good to bludgeon the mix down engineer into bending his VU
meters over the pin. No matter what
the level on the tape is, it will be
knocked down to within reason so it
can get onto a disc. That works the
other way too. If it is too low on the
tape, it will be brought up to the maximum possible along with the hiss on
the disc.
Right channel modulation only
The preceding discussion has been
from a purely technical standpoint. I
realize that you have to go out into the
real world and compete with other
records which were cut hot. That is
really a sad situation. If only we
stayed a dB or two under the absolute
maximum and let records compete on
musical value rather than on how
much distortion you can get away
with, we would have a much better
final product. If you want to hear a
loud sound, the place to turn up the
volume is on the two -kilowatt amplifier, not an unnoticeable dB in a
microscopic groove. The situation
could be likened to pulling a railroad
train with a small motorcycle and
supercharging the motorcycle in order
to go one mph faster, when what you
really need is a diesel locomotive. Well,
before this begins sounding like a sermon, let's get on to another aspect of
this medium.
Quiet Masters
Here is the bright side. It may be interesting to note that there is very little noise generated by the disc mastering system. Master lacquers are at
least as quiet (without any noise reduction at all) as most professional tape
recorders are with noise reduction.
Sometimes they are even quieter, depending on the stylus and the particular batch of lacquers.
A worn stylus will of course cut a
noisy groove, but such a stylus would
become immediately apparent under
the 'scope. Any mastering house
Complex stereo signal -similar to
typical musical program.
worth its salt will never let a stylus get
to the dull point of noisyness. Usually
a test cut is first made on the outer
edge (outside the 12- inch diameter of a
14 -inch blank) to check groove depth
and pitch. A bad stylus would at that
point be immediately discovered. The
cut is then played, and, if the stylus is
beginning to wear, the silent groove
will not be so silent. Again the stylus
will be replaced before a master is cut.
After every master or reference dub is
cut it is inspected under the 'scope.
Here again the groove is checked for a
sharp stylus all the way through. A
dub is played to confirm quality; a
master should never be played. The
acetate is like butter when compared
to the relatively iron -like vinyl, and if
played would ruin the master. If something goes wrong, such as the stylus
hitting an imperfection below the surface of the disc, usually the stylus is
ruined and again this would be evident
upon inspection with a microscope. If
there is an imperfection in the surface,
it will be found during the initial inspection of the lacquer, and the lacquer will be discarded.
There have been attempts recently
to revert back to the old way of making records by avoiding the tape
medium completely and recording
directly onto disc. Unfortunately, we
have become so dependent on our
myriad of sound mangling devices
such as automated mix and so forth
that it is difficult to do a really good
job of recording an entire ensemble
"live," keeping the levels from
shooting through the dropped ceiling
and getting the mix just right. In
Elliptical playback stylus tracing low
-frequency modulated groove.
--
Elliptical playback stylus improperly tracing high -frequency modulated groove (causing distortion or
"smearing").
49
short, doing a one-shot stereo mix
"live." (The way they used to do it
before 32 -track synced recorders ...
even before three -track recorders!) All
the above problems, combined with
the difficulty of getting forty musicians to play for eighteen minutes
straight without making a single noise
or mistake between them, makes a
rather monumental task of such a project. Kudos to those who have tried.
Their efforts have at least given us a
glimpse of what is possible and of how
immaculately clean a record can be.
Unfortunately, the limit is eighteen
minutes even if you could persuade a
group of musicians to do the near impossible. Don't zorget that with disc
if there is only one mistake, even at the
very end, the whole thing must start
from the top again. Try to recall how
many mistakes were made the last
time you were in a recording session
and multiply that by eighteen minutes. That's how long these poor guys
would have to be playing without a
break. Talk about a bill for overtime!
Now after all this blapping about
how quiet master lacquers are, you're
probably saying to yourself, "Man, is
this guy full of crap. That last record I
bought sounds like it was pressed on
asphalt." Well, you are pretty close to
the truth (about the asphalt I mean).
Most of the problems encountered
originate in either plating or pressing,
and I'm not just saying that because I
do mastering. It's just that noise can
be generated in many ways in those
two processes.
Cross section of groove showing the important angles.
In mastering, noise is readily detectable and easily remedied. Not so easily in plating and pressing. First of all,
in mastering there are usually only one
or two parts made and you have time
to closely scrutinize nearly every millimeter of the surface with a microscope.
A pressing plant may be turning out a
million copies of the master. Clearly it
would drive the cost per record up to
about twenty dollars to get excellent
pressings. It can actually be done, but
the consumer doesn't insist that the
thing he buys be top quality. He will
unfortunately settle for nearly any
kind of junk, and he gets it. Some
pressing plants don't care and others
can't afford to, with regard to obtain-
ing the highest possible quality. And
make no mistake, quality costs. Some
plants use re- ground reccrds and
cheap compound. Some don't know
how to cycle the presses for optimum
speed and proper orientation. This lack
of knowledge results in a warp if the
cooling cycle is too short, or something
called "non- fill" if the heating cycle is
too short. Non -fill occurs when the
vinyl does not reach every part of the
groove. You can hear it usually as a
once around gravelly sound. None of
these things can occur in the mastering stage, although we get blamed for
almost anything that goes wrong with
a pressing. But we are already into
another topic.
Fixed and Variable
ACETATE
111111111111111
Cross section of master blank with grooves cut into its surface.
50
Let's talk about the amazing and
dazzling variable pitch/depth machine.
Before this system was developed all
records were cut "fixed pitch." This
meant that the grooves were all evenly
spaced and the carriage moved toward
the center of the record at a constant
speed. The pitch was a simple calculation of available space relating to
angular velocity and time. Level was
solely dependent on the resultant
pitch. If the record was soft until the
very end, as in some classical music,
the level had to be set for that maximum point and all else had to fall
below that no matter how low it was.
That system wasted large amounts of
space and cost dearly in level.
MODERN RECORDING
to18 from 749...
mfiverz
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INPUT FEATURES
BALANCED MIC INPUTS
HIGH Z LINE INPUTS
IN/OUT JACKS
20dB ATTENUATION
MONITOR SEND
ECHO SEND
3-BAND GRAPHIC EQUALIZER
SOLO/PREVIEW SWITCH
LEVEL CONTROL
OUTPUT FEATURES
SOLID STATE LED VU METER
HEADPHONE JACK 'LEVEL
CONTROL
BUILT IN
SPRING REVERB
HIGH/LOW CUT FILTERS
HOUSE/MONITOR LEVEL
CONTROLS
HOUSE/MONITOR OUTS
See your local dealer or
write for our free catalog:
UNI-SYNC
A BSR COMPANY
742 Hampshire Rd.
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(805) 497-0766
TROUPER I
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m
CIRCLE 23 ON READER SERVICE CARD
itch system on the
the program one
the point at which
orded. This is acsans of a preview
nply another play .,u.
neaa on the deck spaced, by
means of a special tape path, a
distance equal to one revolution (about
1.8 sec.) in advance of the program
playback head. By knowing in advance
what is about to occur in the program
(with regard to level) this system takes
advantage of the quiet passages by
keeping the grooves as close together
as possible. Thus it conserves space,
and when a loud passage comes along
it can spread the grooves as far apart
as necessary to keep from overcutting.
The preview head also "reads" the vertical information, and if there is out -ofphase signal which would cause bad
vertical lift, it sends a signal to the cutter to drive the stylus down deeper
into the lacquer- thereby reventing
the cutter from lifting off the surface.
Now this part gets complicated because if there is a deepening of the
groove, this extra width takes up more
room on the disc. So whenever this
happens, a signal is sent instructing
3
the system to accomodate the wider
groove and the lateral excursion.
Future Discs
The older systems were purely
analogue devices which operated on
the program material itself. The latest
units are digital and use computer
technology. They sample the program
more often and more precisely and get
just about the maximum use out of
those 86 square inches. In fact, they
are so fast and so good, that they actually border on being self-defeating
by causing their own problems.
In the future, when technology permits, the preview head will be a thing
of the past and the whole thing will be
done with digital delay. The current
problem with doing that today is that
the program signal would have to
come from the delay signal. This would
mean that the realtime signal would
have to be wasted on the less demanding preview signal. At present, getting
a DDL signal of acceptable quality
with a delay of nearly ±wosec_onds
would cost more than an entire cutting
system. But when that problem is
solved it will be possible to master
directly from an automated encoded
multi-track tape, a digitally encoded
multi-track quarter -inch tape or even
direct from a "live" recording such as
we spoke of earlier. These things are
not going to arrive tomorrow -if they
are in the future at all -but by then we
may have a whole new concept of disc
recording, including video with audio.
In these two issues we obviously
have only scratched the surface of disc
recording. It is a highly technical subject involving a fair knowledge of
physics, geometry and mathematics.
Knowledge of these fields is not
essential to get a feeling for magnetic
tape recording, but to really understand disc cutting such knowledge is
necessary, and enables one to appreciate the precision and close tolerances
of the disc system. Many of the concepts are difficult to explain or understand without talking about groove
geometry, stylus accelerations, groove
velocities, vectors and a hundred other
facts of physical science. However, the
principles covered in this two-part article should give you a solid idea of what
you are up against when you want to
put your artistic efforts onto the disc
format.
4
CLASSS
Snake and UltraSnake.
The classic connector cords especially designed
for use with musical instruments and systems. The
exclusive Snake cable, manufactured for Whirlwind
Music by Belden, features a tough neoprene
exterior lined with a unique noise-free shield.
UltraSnake comes tipped with two solid brass
military plugs; Snake with a pair of nickeled brass
Switchcraft plugs. Both are designed to take the
strain of on -stage patching without fraying at the
ends. Both are available only at your Whirlwind
dealer. There is no substitution.
You get the Snake, or you're left with the hiss.
whirlwind
P.O. Box 1075
Rochester,
N.Y.
14603
(716) 663 -8820
CIRCLE 69 ON READER SERVICE CARD
52
MODERN RECORDING
If)ou can't decide betieen getting
a sunn Q RA.ssstem and an inexpensive
In
P.A. system
bark
At Sunn we've learned that, too oIan,
accounts get in the vvey of your ability :o
a PA. that will suit your needs. So
we've taken tie electronics and manufacluring expelise hat went intc our
Automated Sound Systems and applied it
:
to three, new, inexpensive systems with
'
A
features that -effect the latest in
-:
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practical cenefits. We call -hem oar
,,,.\
ALPHA SERIES. Each A pha P.A.
'
console (4, 6 or 8 channels)
features 100 Watts RMS,
a
Phase Sync® tone controls, high
*.
and law impederce operation, and
the same "intecratee' design of
Automated Sound- Generation
And they start in price at
;*9"
S299.00 (suggested list
a
price)! Wr-e us for more
r ., ,
informaton. Or better yet.
2- _
see your nearest S am
..deale for c free
4.
demonstration. After
`
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all, music's the
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th lìg ...and we're
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here b help!
getbaurchase
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SUNN MUSICAL EQUIPMENT COMPANY
CORPORATq 4 COMPANY
AMBURht INDUSTRIAL PARK
TUALATIN. 011ECDON 97062
A HARTZELL
Name
Address
City
State
01C.02.7'OCi7Vi
Zip
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C D O D D
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E D D O D E
CIRCLE 22 ON REA'CER SERVICE CARD
I
.
-
BY LEN FELDMAN
Z Stands For Impedance
In the course of my musings about various audio
subjects in this column since it began some two years
ago, I have touched upon some complex -and sometimes even controversial technical subjects. This
time I'd like to discuss a fairly basic audio subject
impedance. Professionals and sophisticated recordists
may find some of what I'm about to explain old hat,
but I have the feeling that many of our readers are
often confused about impedance specifications, and
perhaps some fundamentals concerning good old "Z"
might be worth reviewing.
-
-
Some Definitions
Impedance, like resistance is always specified in
ohms. The output impedance of an electronic device
may, however, be purely resistive in nature or it may
have a reactive component, either capacitive or inductive. Reactive components in a given impedance
pedance of the combined reactive and resistive components would add up to 200 ohms, but you'd be
wrong. That is because the two forms of impedance are
90 degrees apart in phase and therefore cannot be
added directly. Vector diagrams are often used to
calculate complex impedances such as these, and, in
the case cited, the vector diagram would look like that
illustrated in Fig. 1. The total impedance (at 1 kHz) in
this example would actually add up to 141.4 ohms (the
hypotenuse of a triangle whose sides equal the resistive and reactive components of the complex impedance) and the phase-angle of the net impedance
would be at 45 degrees, which means that the current
in such a circuit would lead the applied AC voltage by
that amount. In such a complex impedance containing
a reactive component, the value of impedance will, of
course, vary at different frequencies, for while the
resistive part does not change with frequency, the
reactive part does. In the case of a capacitive reactance (as in our example), impedance gets lower and
lower with increasing frequency, while if the complex
impedance contained an inductive component, the
reverse would be true.
Microphone Impedances
Resistive and reactive components must be "added"
vectorially to arrive at composite "net" impedance, "Z."
have the effect of introducing phase shift, or time
delay to an alternating voltage or current. For example, if a given circuit has an output impedance consisting of 100 K ohms of "pure" resistance, and a
capacitance of 1600 micro -micro farads ( picofarads) of
capacitance, at around 1000 Hz, the reactive components of that impedance will also be about 100
ohms. You might therefore suppose that the total im-
54
Armed with the above concepts, let's see why it is
desirable to use low-impedance microphones in audio
circuits when long cables are needed between the
microphones and the input terminals of a preamp or
recording console. Suppose, for a moment, that we
used a high -Z microphone (one having an impedance of
perhaps 10,000 ohms) and had to run a cable of 100
feet between the mic and the tape recorder input. A
diagram of the setup is shown in Fig. 2. The 10 K impedance of the microphone is represented as a resistor
in series with the microphone element. Across it, to
ground, is the effective capacitance of the shielded
cable. Shielded cable, typically, may have a capacitance of as high as 50 picofarads, so a 100 foot run
would "look like" a capacitor of 0.005 mfd sitting
across the line. We can calculate that at a frequency of
only 3,000 Hz, that capacitor would have a reactive impedance of 10,000 ohms -the equal of the microphone's resistive impedance. What that means is that
at that frequency, response would already be "down"
MODERN RECORDING
connected. Suppose a console preamplifier has an output impedance of 600 ohms and is to be connected to a
tape deck input having the same impedance. If the preamplifier were delivering, say 1.0 volt rms of audio
by 3 dB. At higher frequencies, the situation would be
even worse, as the capacitive reactance gets lower and
lower and shunts more and more of the microphone
signal output voltage directly to "ground."
MICROPHONE
0
^
100 Ft. Cabel
10k
ohms
Rm
"_. 0.005
mf
--r- Capacitance
i
1
(10k ohms at.
3 khz)
TAPE
DECK
OR
CONSOLE
Fig. 2
Long cable capacitance "shunts" high frequencies of high impedance mic to "ground."
Now let's see what happens in the case of a low impedance microphone (one having an internal impedance of only 250 ohms, for example). The 100 -foot
cable hasn't changed and still looks like a 0.005 mfd
capacitor hanging across the line. But we can calculate
that in order for its reactance to equal 250 ohms (the
new "series resistance" of the low -impedance
microphone) we would have to apply a frequency of
100,000 Hz before the signal would be attenuated 3
dB. For these reasons, high impedance microphones
should only be used with very short cable runs,
whereas low- impedance mics are preferred where
longer runs (in studios, and the like) are required. (To
signal before the interconnection was made (or the output impedance was "terminated," as we prefer to say
in audio parlance), the voltage appearing across the
"line" (measured either at the output of the preamplifier or at the input of the tape deck) would have dropped by 6 dB and would now measure only 0.5 volts
rms. The diagrams of Fig. 3 help to explain why this is
so. In the unterminated condition, no signal current
flows, so no voltage drop occurs and 1.0 volt appears if
measured by a high- impedance voltmeter. The moment
connection is made to the deck, however, signal current begins to flow. The value of this AC current can
be simply calculated from Ohms Law (I = E/R, where I
Voltage appearing at unterminated 600 ohm impedance drops to half its open- circuit value when terminated with
matching 600 ohm load impedance.
achieve the same roll -off at 100 kHz with our 10 K ohm
mic, the cable would have to be reduced to a mere three
feet long or less!)
Impedance Matching
Even if we discount the presence of reactive components in considering output and input impedances of
audio products that are to be interconnected, certain
rules must be observed. In professional installations,
it is common practice to use 600 -ohm output and input
impedances for products whose signals are to be inter-
a
current, E is voltage and R is total circuit resistance). The total current in this case is equal to 1.0
volt, divided by the total circuit resistance or 1200
ohms (600 ohms of source impedance and 600 ohms of
terminating impedance), or 0.0008333 amperes. That
current causes a voltage drop of 0.5 volts (E = IR; or E
= 0.000833 x 600) across the internal output resistance of the preamp, leaving only 0.5 voltage drop
available to appear across the terminating resistance
of the tape deck input.
In the case of consumer -type audio equipment, it is
common practice to disregard voltage drops of this
is
sort completely because they are usually insignificant.
That is because low- impedance outputs are usually
connected to high- impedance inputs. As an example,
let's assume you have a preamp which has a rated output impedance of a mere 100 ohms (a not uncommon
value) and it is to be connected to a power amplifier input which has a 10,000 ohm input impedance. Now, the
current flowing in this connection loop (illustrated in
Fig. 4) equals voltage applied (assume 1.0 volt rms
again) divided by the total circuit resistance, or 10,100
ohms. The current works out to be 0.00009901. The
voltage drop across the 100 ohm internal impedance of
the preamp works out to be a mere 0.00990099 volts,
(or should) be connected to 8 -ohm impedance loudspeakers (or 4 -ohm types, or whatever) he does not
mean that the internal impedance of the amplifier is 8
or 4 ohms. In fact, the internal , or "looking back into"
impedance of a solid -state amplifier is usually a small
fraction of 1 ohm. It is for this reason that the voltage
appearing at the speaker output terminals is almost
the same whether those output terminals are "open"
or connected to a loudspeaker or other load. What the
manufacturer does mean when he speaks of speaker
output impedances of 4 or 8 ohms is that speakers of
this impedance will draw rated power output (in stated
When low -Z output drives high -Z input, voltage drop across "source" impedance is negligible.
leaving 0.99009901 volts available to be delivered
across the input impedance (or to the first stage) of the
power amplifier. This is so close to the 1.0 volts of
signal available at the "open circuit" output terminals
of the preamplifier that no one bothers to even
calculate the minute difference and we just assume
that the input signal to the amplifier is the full 1.0 volt.
The use of low impedance outputs feeding high impedance inputs in home audio equipment also permits
fairly long cable runs between components, just as in
the case of microphones. There is one important exception to the "long cable" theory and that occurs in the
case of a phono cartridge connected to a phono
preamplifier input. As we have already mentioned,
audio cables introduce shunt capacitance in the line
and just about all phono cartridges (although they
"look like" low impedance sources) are designed so
that they will perform optimally when loaded with
specific values of shunting capacitance. The recommended values may range from 100 pF or so (for CD -4
type cartridges) to 200 or 300 pF for stereo pickups.
Load such cartridges with less than their optimum
capacitance and they will exhibit rising response at
some high audio frequency. Hang too much cable
capacitance on the line and high- frequency roll -off will
rear its ugly head and your hi -fi can turn into low-fi.
Amplifier Output Impedances and Speaker
Impedances
One common source of confusion when it comes to
impedance matching concerns so- called amplifier output impedances and rated speaker impedances. When
an amplifier manufacturer says that his product may
56
watts) from the amplifier safely. Since the voltage is
almost constant at the output of an amplifier regardless of load, connecting a 4 -ohm impedance to an amplifier generally results in higher power delivered to
the load than does connecting an 8-ohm load. (Power
equals voltage squared, divided by load impedance, so,
if the voltage remains constant and load impedance
goes down, power delivered to the load increases.) Of
course, current limitations and thermal considerations
terminate this linear relationship long before you
reach a "dead short," or zero impedance load condition
across the speaker terminals- where, in theory but not
in practice, power delivered should be "infinite."
Those of you who remember the days of vacuum
tube amplifiers will recall that output transformers
used to couple the high-impedance tube -type output
stages to low- impedance speaker loads were equipped
with taps, or multiple screw terminals so that you connected the speaker in accordance with its rated impedance (4, 8 or sometimes 16 ohms). With such transformers, optimum power transfer was obtained from
amplifier to load regardless of load impedance. In the
case of solid state amps, where such multi-tap
transformers have been eliminated, a change of load
impedance changes the maximum power delivered to
the load. But, since transistor output stages are of low
impedance to begin with, a good match is generally obtained over a fairly wide range of speaker impedances
without the need for a matching transformer.
We realize that this brief discussion, as it relates to
audio and recording equipment, only touches upon the
broad question of impedance. If we haven't covered
everything from A to Z, we hope we've at least shed
some light on Z.
MODERN RECORDING
The Peavey
Series
Last year when Peavey
introduced the CS-800 Stereo
Power Amp, professional sound
men and engineers acclaimed it
as the most versatile high
performance power amp
available for under $1,500.00.
Now, there are two
superbly engineered additions to
the Peavey CS series, the CS -200
and CS-400. These new high
performance amplifiers are built
with the same meticulous quality
control and engineering
standards that go into the
CS-800.
We invite you to compare
the features designed into the CS
series. You'll see why no other
power amp offers the value built
into a Peavey.
CS-200 $324.50
*
Monaural power amplifier
200 Watts rms
20 Hz to 50 kHz response
Less than 0.1% THD
Less than 0.2% IMD
LED overload indicator
19 -inch rack mount
Forced air cooling
CS -400 $424.50 *
Stereo power amplifier
200 Watts rms per channel
20 Hz to 50 kHz response
Less than 0.1% THD
Less than 0.2% IMD
LED overload indicators
19-inch rack mount
Forced air cooling
CS-800 $649.50
*
Stereo power amplifier
400 Watts rms per channel
5 Hz to 60 kHz response
Less than .05% THD
Less than 0.1% IMD
LED overload indicators
Loudspeaker protection
system
Balanced input and electronic
crossover capabilities
19 -inch rack mount
Forced air cooling
*Suggested Retail
Peavey Electronics, Corp. / Meridian, Mississippi 39301
CIRCLE 33 ON READER SERVICE CARD
-11q,
/u10ODDCf(
f2CC©fR DII(NG
LAB
NORMAN EISENBERG AND LEN FELDMAN
TEAC A -650 Cassette Tape
Recorder
General Description: Teac's model
A -650 is a
front -loading stereo cassette recorder with numerous
features including Dolby, bias and EQ switching, mic/
line mixing, LED peak indicators, and more. The front
panel, while reflecting all this, is logically planned. The
cassette compartment at the left has a swing-out door
with guides into which a cassette is inserted. The button to open the door (marked Eject) is at the lower
righthand corner of this area.
The center portion of the front panel is given over to
transport controls. There's a three -digit index counter
and its reset button; next to it is a memory switch with
three positions: play is for "memory play" after rewind; "off" disables the memory feature; "stop" will
automatically stop the tape when the recorder's
counter reaches 999.
Pushbuttons for transport action are quick- responding and permit a "limited" degree of fast -buttoning in
that it is possible to go from any of three modes (play,
58
fast -forward, rewind) into any other of those three
without first pressing the stop button. There actually
are seven transport buttons. First is the record control. Next is a "record mute" control which, if pressed
during the record mode, will disconnect the input signal from the heads while the deck continues to record
with no signal (erase) on the tape until the pause or
play button is pressed. This feature permits creating
silent portions during a recording. Next is the pause
button which can stop the tape entirely during record
or play. Each of these buttons has its own indicator
light. Below them are the buttons for rewind, fast forward, and normal forward (play). The stop button is a
larger control under this group.
The righthand portion of the panel contains the VU
meters and various electronic controls. Each meter has
its own LED peak indicator. Calibration is from -20
to +3, and the Dolby calibration point is indicated on
the scale. To the right of the meters is the deck's power
MODERN RECORDING
off/on switch. Below the meters are five switches. One
is a three-position bias switch; the next is a three position EQ switch. The third switch engages a built -in
limiter for possible use in "live" recording. The last
two switches handle the Dolby system, with options
provided for direct -copy recording of Dolbyized tapes;
recording of any non-Dolby encoded source; for direct copy recording of Dolby FM broadcasts that use the
25- microsecond preemphasis; for decoded monitoring
(hearing normal sound) when recording Dolby- encoded
tape or when playing back a Dolby- encoded tape; to
disable the Dolby system when recording or playing
back non -Dolby signals; and finally for decoded
monitoring (normal sound) when recording a Dolby FM broadcast. The last option also applies a multiplex
filter to the input FM signal.
Below these switches are the level controls for input
and output. Mic level controls are separate per channel, as are line input and output controls. Finally, at
the lower righthand portion of the panel are the input
jacks for left and right channel mics, and the stereo
headphone output jack. The output level knobs control
headphone volume as well as the line output volume
from the rear -panel line -out jacks.
At the rear are the line -out jacks plus a pair of line -in
jacks and an optional DIN connector. The rear also
has a pair of adjustments for Dolby FM /copy calibration which is accomplished with the aid of the front panel meters.
For cleaning and degaussing the heads, it is possible
to remove the cassette compartment door cover. Supplied with the A -650 is a small kit containing a head cleaning stick, several applicators and a vial of cleaning fluid. The owner's instructions are given on a large
fold -out form rather than in a booklet, and include a
comprehensive list of tape brands and types with the
recommended bias and EQ settings for each.
ti
Test Results: While
the Teac A -650 is no slouch in
audio terms, MR's testers were more impressed with
its mechanical operation than with its response. Best
audio performance was obtained with CrO2 tape (TDK
SA) and with the bias and EQ switches set to their no.
1 positions. In this mode, we clocked response within
+1, -3 dB from 35 Hz to 14 kHz. Signal -to- noise, without Dolby, was 56 dB down; with the Dolby switched
in, it improved by 8 dB to an excellent 64 dB down. Input and output level readings were all within the ball
park and the A -650 should interface readily with just
about any other audio gear.
Mechanically, the A -650 ran like a champion. Wow
and flutter were 100% better than manufacturer's
specs; fast -wind time beat the claimed time by 5
seconds. Most impressive was the flawless action of
the solenoid-logic transport controls which gave the
user a definite feeling of professional -grade equipment.
Examination of the deck indicated that it is extremely
well engineered and ruggedly built in addition to
smooth-operating.
General Info: Dimensions
are: 175/,6 inches wide;7
inches high; 1219/,6 inches deep. Weight is 283/4pounds.
Advertised price is $550.
Individual Comment by L.F.: For years I have
been a great fan of Teac. The company traditionally
has avoided the use of superlatives in its product
descriptions, and also has taken pains to set the record
straight when it comes to the interrelationships between signal -to- noise, distortion and frequency
response. Tending to go the route of professional
recording equipment, Teac has -in many of its open-
o
1111111111111111111111111111111111111111111
o
o
o
11111111111111111111 111111111
111111111111 IM1111111111111
C/IIIÏÏ111111 111111
20 dB RECOR
LEVEL
I1111111M111111 11111111111111111
1111111111111 11111111111111
1111111111111111111111111111111
20
100
10K 20K
1K
FREQUENCY
- H¢
TEAC A-650: Record/play frequency response using
TDK Audua cassette tape.
reel and cassette models- favored better S/N ratios
and lower distortions while willing to give up the "last
kHz or two" of r/p frequency response.
This is all well and good, say I, except that in the
A- 650 -which is hardly an inexpensive unit -they
seem to have gone a step too far. In this model, they
have gone all out for front -panel features (described
above) which are useful and which do work as claimed.
But what bothers me here is that the basic performance of the sample I tested (and perhaps this one
may not have been "up to snuff') was not quite what I
would have expected these days from a unit in the
over -$500 category. I could easily accept the rather
average frequency-response results, but I was con-
cerned that S/N ratios were also only about average,
considering the deck's cost. Nor could I justify the
rather high THD levels measured for two tape types at
the 0 VU recording level. I know that "0 VU" can be
calibrated wherever a manufacturer chooses for it to
assume that a company with its experience and savvy
deliberately chose its design and performance parameters, not to mention the unit's features, for what it
regards as a definite market for this product. I feel
that the response, while not spectacular, is still very
occur (in terms of actual recording level, measured in
nanowebers), but I fail to see why Teac elected to make
their "0 dB" indication come so close to the saturation
point of the tapes involved, as indicated by the rather
low headroom ( +2.5 dB) available with the SA sampler
before reaching the 3% THD level.
On the plus side, no one can fault the transport
system of the A -650. Its wow and flutter exceed Teac's
spec by far and it is indeed as low a figure for wow and
flutter that we have measured in any home-type cassette recorder. Nor is Teac "covering up" anything by
using a weighted figure, for even measured without
weighting (RMS), the wow and flutter still turned out
to be an impressively low 0.08 %.
good. Signal-to- noise, topping the 60 -dB mark with the
Dolby switched in, seems to me better than "average."
Distortion for 0 VU recording level does stay under
two percent with either normal or chrome tape, and the
headroom for using normal tape is a healthy +6 dB.
This drops, of course, to only +2.5 dB with chrome
tape and so here we encounter a design trade -off which
one can either accept or not, depending on his
philosophy of cassette recording. In view of these factors, and of the unit's sterling mechanical operation, it
is difficult to say unequivocally who will "like" it or
not. I suppose if the price were significantly lower,
there would be no hesitation about recommending it
more "universally."
TEAC A -650 STEREO CASSETTE RECORDER: Vital Statistics
PERFORMANCE CHARACTERISTIC
LAB MEASUREMENT
Frequency response, normal tape
(TDK -Audua)
Frequency response, Cr02 tape
100
10K 20K
1K
FREQUENCY
-
Hz
TEAC A -650: Record /play frequency
TDK
response using
Individual Comment by N.E.: It seems
obvious
that Teac, with an already extensive line of recorders,
opted to introduce this model in terms of its possible
special appeal to one group of users in the steadily increasing army of cassette -recorder buyers. One has to
60
14 kHz
Harmonic distortion at 0 VU
(tape 1
/ tape 2)
1.8%
Recording level for max 3% THD
(tape 1
/ tape 2)
+6
Signal -to- noise, unweighted
w/o Dolby (tape 1
tape 2)
with Dolby (tape 1 / tape 2)
54 dB
61 dB
Wow and flutter (WRMS)
0.03% (0.08% unwtd).
Fast -wind time (C -60)
Mic input sensitivity
85 seconds
Line input sensitivity
60 mV
Line output level
270 mV
Phone output level
9
Bias frequency
100 kHz
Power consumption
25 watts
/
"SA" cassette tape.
-3 dB, 35 Hz to
+1,
(TDK-SA)
20
±3 dB, 35Hzto14.5kHz
/
2.0%
/
dB
+2.5
/
/
dB
56 dB
64 dB
0.26 mV
mW into
8
ohms
CIRCLE 16 ON READER SERVICE CARD
J
MODERN RECORDING
Electronic
Echo Unit
H. H.
General Description: The "Echo Unit"
(no model
number is given) from H. H. Electronic uses a tape
loop system to produce echo sound and is primarily intended for use in conjunction with instrument or P.A.
amplifiers or mixers. A stereo connection option permits splitting the "dean-feed" and echo into two
separate component signals. This method is designed
to produce a full stereo image with clean -feed handled
by a stage amplifier and the delayed echo signal
delivered through the main P.A. system (or a separate
instrument stack if desired). It also is possible to add
effects to a stage amplifier in the normal way (e.g., sustain or reverb, etc.) without affecting the echo signal.
Front panel facilities include gain controls for
signals connected to inputs 1 and 2; a treble control
(handles both channels simultaneously); an echo
volume control; an echo repeat or "duration" control; a
bass control (affects the echo signal only); another
third accepts a hookup from an optional footswitch to
provide remote control of the echo signal on or off. At
the extreme right is the power switch for the device.
The rear panel contains standard phone -jacks for the
input from echo send, and the output to echo return.
There also is an operating voltage selector (110 -120
VAC; 220 -240 VAC); a fuse -holder (1 amp serves for
both AC positions); and the power connector line
which is a Euroconnector having three pins. The unit is
supplied with a suitable power cable two meters (about
79 inches) long plus two shorter signal cables. It is
finished in a leatherette surround and has a slip-on
cover.
The signal-producing tape loop is found just under
the top cover of the device and consists of a length of
recording tape enclosed in a transparent casing and
forming a loop. The tape emerges from an opening at
one end of the housing, passes through a tension
H.H. Electronic Echo Unit: Front panel view.
treble control (also for the echo signal only). Centered
below these knobs is a horizontal slider for echo delay
which may be adjusted to vary the time delay of the
echo. To its left are phone -jack inputs for channels 1
and 2, and an echo -on pushbutton for each input. To
the right of the delay slider are three more phone
jacks. One is for the echo -out signal; another is for the
normal output connection to other equipment; the
SEPTEMBER 1977
spring and guide wheel, goes past three widely- spaced
heads, and is engaged by the motor shaft and a rubber
pinch wheel just before it returns to another opening
at the opposite end of the housing. According to the
manufacturer, the tape will run for at least 300 hours
or more without perceptible loss of performance if
transport and heads are kept clean. Instructions for
replacing the tape are given in the owner's manual
which also cautions that only the special tape supplied
by H.H. is to be used.
Test Results:
MR checked the measurable performance areas of th H.H. Electronic Echo Unit in
both its "clean feed" and "delayed feed" sections, and
H.H. Electronic Echo Unit: Internal view
monizers and audio -delay circuits that I had almost
forgotten how these audio tricks used to be performed.
Well, if nothing else, the H.H. Electronic Echo Unit
has served to restore some of my lost perspective. This
is actually the way echo effects were (and still are) produced before the advent of all those miraculous circuit
shows tape storage area and tape heads which are used to pro-
duce echos.
with results that either confirmed or exceeded
the published specs for the device. To study the action
closely, a tone burst was introduced, and the echo gain
was set somewhat below the input level gain, with the
repeat control adjusted to about three- quarters of the
way to maximum. The resultant signal is shown in the
accompanying 'scope photo, which portrays graphically the delayed repeat echo action.
The tape in the loop travels at 12 inches -per- second
speed, and the movable head (controlled by the echo
delay slider) can vary the echo time from about 100
milliseconds to more than 700 milliseconds.
In "live" use tests, a guitar player used the device
connected to a guitar amplifier and the results were
judged to be versatile, very effective and clean sounding. The double input facilities on the Echo Unit were
considered to be a clever addition since they permitted
a pair of instruments to take advantage of the machine's echo capabilities, though -to be sure -the
degree of echo and of the echo repeat settings come out
the same for both inputs. Only the level of each can be
varied individually since the tone controls act on both
sources simultaneously.
came up
General Info: Dimensions are 193/4 inches wide; 41/2
inches high; 111/2 inches deep. Weight is 19 pounds.
Advertised price is $575.
Individual Comment by L.F.: It is interesting to
see how some of our more sophisticated electronic
equipment's functions can be duplicated by electromechanical means. I suppose I have become so blase
about digital time -delay units, "bucket brigade" har-
62
chips that manage to compress time, alter frequency,
and do all the other magical things that performers
bring to their stage appearances and recordings.
So obviously there is still something to be said for
tape -loop echo. With the digital and all -electronic
H.H. Electronic Echo Unit: Signal at left is "clean
feed" tone burst, followed by "delayed" rep3ating
echo signals.
devices we have seen, there are limits to the quality of
sound you can get as you approach the extremes of
time -delay of the electronics. The frequency response
of the delayed signal also can be affected by changing
the time of the delay. In the case of this electromechanical system, the fidelity, the distortion and the
consistency of the recovered echo signal are main-
MODERN RECORDING
tained intact regardless of the time of the echo
selected. This also applies to the repeat -echo function,
which means there is no need to compromise for a
change in the quality of the echo effect just in order to
be able to vary the time parameters.
The one problem we experienced with the device was
the failure of the capstan pinch wheel to disengage
from the capstan when the echo feature is turned off,
or when power to the unit is turned off. This, despite
the statement in the owner's manual that a solenoid is
supposed to have disengaged the pinch wheel. Obviously, with this problem, the unit will develop flat
spots after some period of use.
Individual Comment by N.E.: This British -made
unit has all the solid, no- nonsense "feeling" about it
that is customarily associated with quality products
from the U.K., as well as some of the uniquely British
"shticks" -like the unfamiliar AC power socket (fortunately a mating cord and connector is supplied), and
such terminology as "earth" for "ground" or "mains"
for AC power lines. If you can get over these little differences from U.S. usage (including the spelling of
"colour" and the term "screened" instead of
"shielded" when referring to hookup cable) you really
might take a liking to this device, since it does its job
very much "as advertised." My sample too had no way
of disengaging the capstan from the pinch wheel, and I
really wonder about that. It could be a real blooper on
someone's part and should be checked out before buying the device.
H.H. ELECTRONIC ECHO UNIT: Vital Statistics
PERFORMANCE CHARACTERISTIC
LAB MEASUREMENT
"Clean Feed" Section''
Gain
7 dB
Normal level
Reference
Maximum input
5.3
Treble control range
+15
Nominal output (for reference input)
225 mV
Maximum output
Frequency response
11.8
V
dB at 10 kHz
V
-3 dB,
20 Hz to 10kHz
"Delayed Feed" Section
Minimum delay
100 milliseconds
Maximum delay
720 milliseconds
Frequency response
-3 dB, 60 Hz to 10 kHz
Bass control range
+10, -11 dBat100Hz
+13, -15dBatlokHz
Treble control range
Compression slope
3
Echo Out level
100 mV for 50 mV input
Tape speed
12 ips
dB increase in output for 30 dB
increased input
CIRCLE 4 ON READER SERVICE CARD
BGW Model 500D Power
Amplifier
.i14,«.. try, ,. iIVIA*11
11141,1
General Description: The model 500D is a stereo
power amplifier conservatively rated for 200 watts
output power per channel, and capable of offering
higher power than that without exceeding rated distortion. It can drive 8 -ohm loads or 4 -ohm loads, and also
SEPTEMBER 1977
..v
may be operated monophonically for an output of at
least 500 watts. It also can cope with 2 -ohm loads, and
even lower with the use of an isolating series capacitor.
The front panel, of rack-mount dimensions and fitted
with handles, sports only a power off/on switch (and in-
dicator lamp) which also serves as a circuit -breaker.
Built into the amplifier is a sophisticated protection
system that includes a so- called "crowbar" circuit
which, in the event of excessive DC voltage at the output, will trigger a fast discharge pulse that gates an
SCR crowbar -essentially a direct short across the
two power supplies. When activated, the normally
Input jacks are at the rear and each jack has its own
gain adjustment. Speaker terminals are standard binding posts, and a warning note advises the use of
speaker fuses. The owner's instruction manual explains their use, and what size to add with regard to
speaker impedance and peak-power anticipated. Also
on the rear panel is a switch to convert the amplifier to
BGW 500D: Rear panel view.
high current that then flows in the primary circuit
disconnects all power via the circuit breaker in a fraction of a second, thereby protecting the loads
(speakers) hooked up to the unit.
There are ten output semi -conductors per channel,
mono operation. Instructions for the correct speaker
hookup in this instance are provided. As supplied, the
BGW 500D is internally wired to operate on the power
source in a given locale; alternate power line values
(the full list is 100, 120, 200, 220 and 240 VAC) may be
BGW 500D: Top view with cover removed to disclose output transistors and heat sinks.
and all are in intimate contact with massive heat sinks. The bias circuit also is mounted on this
assembly which helps ensure bias stability with regard
to temperature.
Built into the amplifier is a cooling fan whose rotational speed varies in accordance with the temperature
of the heat sinks. The fan vents via the rear panel of
the amplifier.
64
used with internal wiring modifications, described in
the owner's manual. The AC power cord has three conductors and is fitted with a grounding plug that should
not be defeated.
Test Results:
The BGW 500D did everything
claimed for it, and then some. In all performance areas
MODERN RECORDING
it exceeded published specs for 8 -ohm loads, and did
extremely well too at 4 -ohm loads (significant performance tests for both loads were run by MR and are
summarized in the accompanying data). In addition to
furnishing extremely high, very clean power output
374W FOR 0.25%THD &
IM
0.18
0.16
11
ALL CHANNELS DRIVEN
8 -OHM LOADS
0.14
INPUT:
0.12
1
-THD
0.10
kHz
0.08
0.06
can be installed and just about forgotten from the
standpoint of worrying about it or having to get at it
for servicing. Of course our tests were necessarily
limited in time but even so, careful examination and
putting the unit through its paces seem to bear out
this "vote of confidence." The 500D not only puts out
a hell of a lot of power but it does so cleanly and with a
good deal of built -in "resistance" to external disturbances, as from improper loads. Indeed, there seems
virtually no load that could be considered "improper"
for this monster.
In our tests the amplifier did not exhibit any significant "rising distortion" at low power output levels.
0.04
0.02
0
1
1
1000
100
10
0
POWER OUTPUT /CHANNEL
- WATTS
BGW 500D: Harmonic and intermodulation distortion characteristics, 4 -ohm loads.
levels, the model 500D also proved to be a very ruggedly built amplifier that would appear to be capable
of functioning reliably for long periods of time under
all sorts of environmental conditions. It thus seems
like an ideal unit to consider for use as a studio
monitor amplifier, or a sound -reinforcement amplifier.
It also could serve as a hi -fi system amplifier except
0.18
0.16
ALL CHANNELS DRIVEN
0.14
8 -OHM
INPUT:
0.12
LOADS
1 kHz
-THD
-IM
0.10
-
i
247W FOR 0.1 %THD
260W FOR 0.1% IM
-
I
0.08
0.06
f
0.04
I
-4_ -...
0.02
0
1
1
0
- -- -- z-I..
POWER OUTPUT /CHANNEL
-
0.08
0.06
0.04
0.02
10K
1K
100
10
FREQUENCY
-
Hz
BGW 500D: Distortion vs. frequency, 8 -ohm loads.
Our measurements speak for themselves, but we did
listen to the 500D too. It did extremely well reproducing material loaded with high transient content. Since
BGW makes a big point of the great open-loop gain of
their amplifier (which means a great deal of negative
loop feedback) we half expected to hear some evidence
of transient distortion. But we did not. Apparently,
BGW's use of fast -switching devices, and their overall
circuit arrangement, are such that they have been able
to get away with such extremes of feedback without
encountering its presumed disadvantages.
100
10
BOTH CHANNELS DRIVEN
AT 200 W /CH. OUTPUT
0.10
1000
WATTS
BGW MODEL 500D POWER AMPLIFIER: Vital Statistics
BGW 500D: Harmonic and intermodulation distor-
tion characteristics, 8 -ohm loads.
for the obvious problem of the noisy fan. If used in a
home sound system, MR advises installing the 500D in
such a way that you won't hear the fan whirring,
especially during quiet musical passages.
General Info: Dimensions are
19 inches (standard
wide; 7 inches high; 12 inches deep.
rack mount)
Weight is 52 pounds. Price: $879.
Joint Comment by N.E. and L.F.:
LAB MEASUREMENT
Continuous power/channel at
247 watts into 8 ohms;
347 watts into 4 ohms
Continuous power /channel,
20 Hz to 20 kHz
1
kHz
211 watts into 8 ohms
10Hz to 30 kHz into 8 ohms
Power bandwidth
Frequency response
-3 dB,
Damping factor
200
THD for rated performance
0.006% into 8 ohms
0.01% into 4 ohms
IM for rated performance
0.011 % into 8 ohms
0.023% into 4 ohms
1
Hz to 65 kHz
+
Residual hum and noise
-110
Input sensitivity
2
dB
volts
BGW's
model 500D seemed to us like the sort of amplifier that
SEPTEMBER 1977
PERFORMANCE CHARACTERISTIC
CIRCLE 9 ON READER SERVICE CARD
65
Uni -Sync
Trouper III Output
Control Center
By Jim Ford
and Brian Roth
General Description:
Uni -Sync, Inc. manufac-
tures a range of four different "live" sound mixing
systems. Each system consists of an output control
module and up to three input expander modules that
allow system expansion to thirty -four microphone inputs, depending upon the configuration.
We field tested the "TROUPER III" output
control center. In this particular system, each
microphone input channel includes:
A) Slider -type volume control.
B) A "solo" rocker switch.
C)
Low -, mid- and high- frequency equalization slider
controls.
D) An echo-send slider.
E) A monitor -send slider.
F) Two rocker switches
that alter the microphone
input sensitivity by
10 or 20 dB (or 30 dB when
used together).
G) Four output bus assignment rocker switches.
H) A peak overload "LED" indicator.
Since the Trouper series is specifically designed for
"live" applications, a number of features that are not
found on most mixers have been included. For example, the Trouper provides a mono output mix derived
from the four output bus submasters (which are
straight line sliders). This allows the inputs to be sub mixed into the four submasters, which then act as
group master controls. This simplifies "live" mixing
situations particularly when using a large number of
microphones. Additionally, each of the four groups has
additional equalization available in the form of three
sliders for low-, mid- and high- frequency control. A
solo rocker switch is included above each group master
level control slider, as is a peak overload "LED."
Other features of the Trouper are two "Announce"
microphone inputs. Each of these provides two
volume -control sliders. One feeds the announce
66
microphone to the "house" mix that is derived from
the four submasters, and the other slider feeds the announce microphone to the monitor mix bus. Two
rocker switches associated with each announce input
vary the input sensitivity by 10, 20 or 30 dB.
Two line inputs are included, and these can be fed to
the monitor or house mix by means of two slider controls on each line input.
Straight -line sliders are provided for the "house"
level master and the monitor master. Each of these
outputs also includes a "solo" rocker switch. A
straight -line slider controls the echo return level to the
"house" mix. Another slider varies the level of the
headphone output signal which appears at the front
panel "phones " jack.
A rocker-type power switch is located on the front
panel as is the fuse holder (the latter is usually located
in the least accessible place on most mixers). On our
review sample, a standard mechanical VU meter was
provided, although Uni -Sync's literature indicates
they are now using an "LED" light meter instead,.
Last, but not least, of the front panel controls is a
rocker switch labeled "prefader" and "solo bus." This
switch is associated with the solo switches on the input, submaster and output positions. The position of
the switch determines the signal monitored by the VU
meter and the headphone output. When this switch is
in the "solo bus" position and any of the solo switches
are turned on, the meter and phones output monitor
the level of that particular input or output after the
fader volume control. In the "prefader" position, the
solo feed is derived before the volume control of the input or output that has a solo switch in the "on" position. All in all, a most unusual and effective monitoring arrangement.
The rear panel contains the necessary 3 -pin "cannon" type connectors for the four microphone inputs,
the two announce microphone inputs, and the house
MODERN RECORDING
The color-coded rocker switches were a nice feature.
However, these particular switches do not have a very
positive action, and it was possible to have the
switches in an undesired middle position that would
negate their function.
The solo/preview system was quite useful for monitoring various signals throughout the mixer. We
would have preferred that the meter and headphone
monitoring circuits automatically switch back to the
house output if none of the solo switches were turned
on; this would eliminate a bit of confusing switch flipping when attempting to solo one of the inputs.
The mixer appeared to have a tremendous amount of
gain. In fact, the amount of gain seemed to be excessive. In moderately loud situations we found it
necessary to operate the input sliders toward the bottom end of their range even with both the 10 dB and 20
dB pads switched in. Also, we occasionally found it
possible to overdrive the inputs with very loud signals
(e.g. a condenser mic on a snare drum), even with all
HOUSE OUTPUT NOISE (see text)
and monitor outputs. These inputs and outputs are
balanced, low impedance and transformer isolated. A
pair of 1/4 -inch "phone" jacks provide the two line inputs. Four other phone jacks allow outboard equipment (equalizers, limiters, etc.) to be patched into the
four submasters. Two other phone jacks provide echo
send and echo return facilities. Phone jacks also allow
external equipment to be patched into the house and
monitor outputs.
Multi -pin connectors provide the necessary connections for three input expanders. Each input expander
provides ten low -impedance microphone inputs with
facilities identical to the output control unit's
microphone inputs (described earlier). Other multi -pin
connectors on the rear of the master control unit provide DC voltage to power other Uni -Sync accessories
(graphic equalizer, etc.)
A slide switch on the rear panel bypasses the submaster facility and mixes the microphone inputs
directly into the "house" output slider control.
Another slide switch activates a phantom power supply which allows certain condenser microphones to be
used with the mixer.
The Trouper unit is designed for rack mounting. Our
sample was housed in an optional road carrying case.
In summary, the Trouper system is of very flexible
design. It incorporates a number of unique functions
that make the soundman's job easier.
Unweighted noise, referenced to 0 VU +4 dBm)
Output terminated into 600 ohms
(
20 Hz -20 kHz 400 Hz -20 kHz
House master off
House master normal ( -15)
House master and all group
masters normal -15)
House master and 1 group
master normal, 1 input set for
20 dB gain
House master and 1 group
master normal, 1 input set for
40 dB gain
House master and 1 group
master normal, 1 input set for
60 dB gain
Equivalent input noise
Typical mix (see text)
(
SEPTEMBER 1977
-69dB
-89 dB
-70dB
-60
dB
-69 dB
-64
dB
-70
-62 dB
-61
-68 dB
-65 dB
dB
-121 dBm
- 54 dB
dB
-125 dBm
-63
dB
Harmonic Distortion at 0 VU (1.25 volts RMS) (see text)
40 Hz
.07%
.02%
.025%
kHz
10 kHz
1
Harmonic Distortion at +20 VU (12.5 volts RMS)
.12%
.012%
.3%
40 Hz
kHz
10 kHz
1
Intermodulation Distortion
(60 Hz
and 7000 Hz mixed 4:1
- SMPTE
method)
At 0 VU (1.25 volts EMS)
At +20 VU (12.5 volts RMS)
Field Test:
Since we had only the output control
module available, we used it as an outboard submixer
in conjunction with another mixer.
We found the extensive use of sliders most unusual,
although not impossible to adapt to. We wished that
the equalization sliders weren't so close together; it
was somewhat difficult to vary an equalization control
without moving one of the others. This was particularly true of the mid- frequency control.
- 88 dB
.015%
.02%
Maximum output level at clipping, in volts RMS and dB
volts RMS)
Frequency
With high impedance load
50 Hz
18.5 volts ( +27.5 dB)
19 volts ( +27.8 dB)
19.5 volts ( +28 dB)
10 volts ( +22 dB)
kHz
10 kHz
20 kHz
1
(0
dB =.775
With 600 ohm load
volts ( +25.8 dBm)
16.5 volts ( +26.5 dBm)
16.5 volts ( +26.5 dBm)
8.75 volts +21 dBm)
15
(
67
the pads "in." High gain is nice to have but not at the
expense of handling really hot signals.
In our application, the mixer was moderately quiet,
although for situations requiring more gain (i.e.
acoustic groups, public speaking applications, and
other quieter situations) the Trouper might be a little
bit noisy.
The unit had a clean sound overall when operated
properly. We felt that the low- frequency equalizer
+1
áa
1111111 1111111111111
111111
1111111_ 111111
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lien
I1111áI11111111
111111
111111 -111111111 111111 1/111111
11111111101111111
-3 11111111
%611
\111111
Respont with tone controls
-4
1111
111111
tone "ontrolt
- -- :gym a aY°,f;a,h
1111 --111111
-6
111
-7
111111
10Hz
111111
2
=
5
adÌUS ed
for best square wave r¢iponse and
Hattest fr¢quancy response.
'
1
I
_
100Hz
kHz
Trouper Ill: Response (overall).
House output.
10k Hz
100kHz
Microphone input,
sounded a bit "boomy or "boxy," an indication that
it is affecting the upper bass and lower midrange
regions more than necessary. The midrange control
was rather "peaky" sounding. The high- frequency control sounded fine.
We noted that the phantom power supply wouldn't
operate Neumann condenser microphones, which require 48 volts DC as opposed to the 24 volts that the
Trouper supplies. However, just about every other
brand of condenser microphone will operate at this
voltage.
Basically, the Trouper seemed to behave in a good
fashion with only a couple of exceptions, mainly the
very high amount of gain.
Lab Tests:
The tables and charts outline our
measurements of the Trouper. While running noise
tests, we noted that a good portion of the noise consisted of hum components. We didn't notice an excessive amount of hum in actual usage, which indicates
very clearly that the human ear is very insensitive to
low frequencies at low levels (just like Mr. Fletcher and
Mr. Munson said many years ago). Consequently, we
have included a set of measurements that filter out the
low- frequency region. These figures are more representative of the actual perceived noise level of the mixer.
As usual, we have included a "typical mix" measurement that was made with all controls in a position
similar to that used in our field test.
We checked the maximum amount of gain of the
mixer (level controls wide open and all pads switched
out) and found it to be in excess of 100 dB! Since the
noise level naturally increases with increasing gain, we
feel that this much gain is not necessary since a very
high noise level would result. A maximum gain of perhaps 70 or 80 dB would allow easier operation of the
mixer with sufficient amplification for low level inputs.
The house and monitor outputs are capable of a very
high output level, an important feature in "live" applications. Few mixers on the market can achieve these
levels.
The frequency response plot taken with the equalizers set mechanically "flat" is fairly good, with the
frequency extremes rolled off. Square wave tests
seemed to indicate that the equalizer controls were not
actually "flat" when set to their mid positions. Adjusting the equalizers for best square wave response
improved the overall response somewhat, particularly
at the frequency extremes.
Harmonic and intermodulation distortion figures
were overall quite low. The low frequency THD
measurements at "O VU" were masked by the hum
level, so actual distortion figures are lower. High frequency distortion was generally low; at higher output levels we noted slew rate limiting, a characteristic
of the operational amplifier "I.C.s" used in the mixer.
This phenomenon causes a rapid increase of highfrequency distortion at high- output levels. As we have
noted in other reviews, this characteristic was not
noticed in usage, but "faster" I.C.s most likely would
improve matters.
The maximum input that the microphone inputs
could handle was around -2 dBm (about .625 volts
RMS), slightly less at low frequencies. The input
overload light illuminated at about 2 dB below input
clipping. The overload light in the VU meter assembly
illuminated at about +5.75 dB above "O VU." All of
the overload indicator "trip points" of the Trouper III
are internally adjustable.
We checked the inside of the mixer, and construction
standards appeared to be good. All of the active circuitry plugs into a motherboard that also holds the
numerous faders and switches. Serviceability appears
excellent with perhaps the exception of access to the
sliders and switches. Sockets are provided for the integrated circuits and transistors, making their replacement a breeze. The overall quality of components
(resistors, capacitors, etc.) seems adequate.
Generally, the Trouper III performed as satisfactorily on the test bench as it did in the field.
Conclusion:
Uni -Sync has designed a remarkable
series of very flexible mixing systems. It is obvious
that they have listened to some design suggestions
from the real world rather than simply adhering to the
design engineer's "slide rule" approach so often found
in equipment. Some areas could stand improvement,
but overall the Trouper performed well.
One final note -the owner's manual was one of the
most extensive and informative we have seen. In particular, the service manual portion was superlative.
Page upon page of schematics, printed circuit board
layouts, parts location diagrams and detailed parts
lists should make repairs of the Trouper very straightforward. Too many other manufacturers keep their
"innards" a dark secret, much to the chagrin of the
service man. Uni-Sync has wisely taken the opposite
approach. Well done!
CIRCLE
3
ON READER SERVICE CARD
4
MODERN RECORDING
The Art
Recordi
of
I_
LEARN HOW THE PRO'S DO IT! THE
NO
RECORDING INSTITUTE OF AMERICA OFFERS
ON- LOCATION CLASSES IN THE LATEST
MULTI -TRACK RECORDING TECHNIQUES
AT A 16 -TRACK STUDIO IN YOUR CITY.
Today's music conscious society has
made recording "the new art of self
expression."
The Recording Institute of America
offers a ten week course in the art of
multi -track recording. The course, entitled MODERN RECORDING TECHNIQUES, is unique in that all sessions
are held on location in professional
16 Track RIA affiliated recording studios in order that the students may see,
hear, and apply the techniques of
modern recording. Under the guidance
of qualified, professional recording engineers as instructors, the student will
become familiar with modern state of
the art equipment.
Selected sampling of topics covered are:
Mono, Stereo, Multi -Track
(4, 8, 16
Recorders
-
Track) Magnetic Tape
Theory and Operation.
Microphones -Basic Theory and Operation.
Control Console- Function
ation- Record
and
The Recording Institute of America, is
the only national institute of its kind,
striving to provide a higher standard of
artistry within the recording industry
and its related fields.
Call Toll FREE:
(800) 421 -0550*
* OR CALL OUR LOCAL REPESENTATIVES
IN THE FOLLOWING CITIES:
DETROIT, MICH.
NEW YORK, N.V.
Pro Sound Studios
RIA
1313) 779 -1380
1212) 582.0400
CHICAGO, ILL.
RIA - Chicago
13121 383 -7494
looked to as the first credible
and informative link between
RIA
is
and Oper-
Mixdown Princi-
ples
"Over-dubbing Principles.
Echo Techniques.
'Equalization and Limiting Principles.
"Multi-Track "Mixdown" Principles
(16 Track to 2 Track Stereo)
'Tape Editing Techniques.
The course includes live 16 Track recording sessions offering the student an
opportunity to apply the related techniques learned.
DALLAS, TEXAS
Sound Techniques Inc.
1214) 638.3256
HOUSTON, TEXAS
LA /ORANGE COUNTY, CA
United Audio
17141 542.4427
Wells Sound Studios
1713) 688 -8067
PITTSBURG, PA.
Audio Innovators
(412) 391 -6220
TULSA & OKLA. CITY, OKLA
Ford Audio and Acoustics
(405) 525-3343
NEW HAVEN, CT.
Trod Nossel Productions
1203) 269-4465
PHOENIX & TUCSON, ARI2.
Lee Furr Studios
1602) 792 -3470
BALTIMORE, MD.
Sheffield Rec's Ltd., Inc.
(3011 252-2226
WASHINGTON, D.C.
United Recording Co.
13011 588-9090
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Reviewed by:
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has
EARL SCRUGGS REVUE: Family Portrait. [Ron Bledsoe, producer; Gene
Eichelberger, Ron Reynolds, engineers;
recorded
at Columbia Studio A,
Nashville, Tenn.] Columbia PC 34346.
Performance: More varied than
consistently avoided stressing
their main attribute -an uncommon
degree of musical dexterity. Save a few
bars on "Daydream," most of Randy
Scruggs' work is obligatory chordal
maintenance. Daddy Earl, a legendary
banjoist, seems to play as little as
possible, and when he does, he's deeply
buried in the mix.
Why are pickers such as Randy and
SEDGWICK CLARK
NAT HENTOFF
JOE KLEE
GIL PODOLINSKY
HOWARD ROLLER
RUSSELL SHAW
Earl embarrassed to solo? Worse yet,
when they do succumb to the urge,
why are they then buried in the mix?
The only possible answer is that
somewhere, there lurks a heavy a &r
man convinced that the public prefers
watered-down musicianship and familiar harmonies over the more ethereal
bluegrass material which lies at the
root of the Scruggs legend.
R.S.
most
Recording: Where's the banjo?
By now, most Earl Scruggs fans
have readily accepted the fact that, at
least for the present, of daddy Earl is
just gonna sit in the background, play
two or three solos per record, and let
his sons do the rest. Obviously trying
for a more contemporary sound, his
shrinking violet approach has been
scorned by those who rightfully consider the contributions of his sons an
exercise in derivative plagiarism.
The tunes on Family Portrait are
catchy; some of the lyrics capture the
ear. Nobody has ever found any fault
with the guitar playing of Randy
Scruggs, who could be a major voice
on the instrument if he wanted to be.
Yet the tunes are photocopies of
familiar themes made popular by other
so- called "country rock" bands such as
Pure Prairie League, Marshall Tucker,
the New Riders and many others. It
doesn't truly break new artistic
ground when the Scruggs sons write
something cliched like "Tall Texas
Woman," which discusses the implied
and hackneyed subject with the
obligatory idolatrous references to the
revered lady in question.
By locking themselves into this narrow format, the Earl Scruggs Revue
70
EARL SCRUGGS REVUE: Avoiding their main attributes.
MCC ERN PECORDING
SYMPHONIC
SLAM:
Symphonic
Slam. [George Semkiew, Timo Laine,
producers; George Semkiew, Mick
Walsh, engineers; recorded at Phase
One Recording Studios, Toronto,
Canada.] A & M Records SP 4619.
Performance: Intriguing
Recording: Needs work
Don't be misled by the title and
group name to think that this is
another disco treatment of the
classics. Rather, this modern day trio
is comprised of drums, synthesized
guitar and keyboards. This is the first
album to feature the new 360 Systems
Polyphonic Guitar Synthesizer, and
the age and versatility of the synthesizer seems to be coming into its
own. The combinations of synthesized
instruments and engineering and the
possibilities rendered thereof are
limitless, though this album did little
more than introduce the speculation.
The recording itself is rather busy,
with many things going on at once.
The instruments were all placed upfront in the mix with the vocal tending
to be rather flat and slightly removed.
Echo is a common occurrence and the
ensuing music tends to drown out the
last words of each vocal line. There is a
frequent use of panning the synthesized guitar, usually on a descending
run which is always too short for effect
and therefore meaningless. The effect
of recording cymbal crescendos climaxing into synthesized strings is
quite reminiscent of early King Crimson. The use of sound effects which
tend to dilute rather than supplement,
such as the train effects in "Modane
Train," has to be questioned. The use
of synthesized bass is more adaptable
and varied than the electric, though it
cannot be as active without extensive
overdubbing of instruments to compensate for too few hands. Although a
good point of reference, Slam needs
vocal and lyrical work and both musicians and engineers need to lose old
cliches.
G.P.
GENESIS: Trick of the Tail. [David
Hentschell, Genesis, producers; David
Hentschell, Nick Haddock Bradford,
engineers; recorded at Trident Studios,
London, Eng.] ATOO SD 36 -129.
Performance: Best yet
Recording: Well suited
Hentschell, who
SEPTEMBER 1977
also
engineered
GENESIS: Distinctive and paying off.
their previous album, A Lamb Lays
Down On Broadway, seems to have
caught the knack for showing the best
side of Genesis -one of the few progressive English groups who still allow
an outsider to partake in production.
The results in the past have been inconsistent due to the constant change
in producers and engineers. However,
by using virtually the same production
team on the last two albums, their
sound has been enhanced to the point
of becoming distinctive.
This album is quite a surprise and
comes at an unexpected time in
Genesis' career. Having just lost
singer /songwriter /main focal point
Peter Gabriel, one would expect that it
would take several albums for the
group to get on track again. Instead,
this eight year old band has released
its best effort yet. Rather than replacing Gabriel, Genesis now functions as
a quartet. The writing credits are now
evenly spread amongst the band's
members, giving Genesis more energy
and unification.
Overall, this is the first time that the
production and engineering have been
able to "bring home" the material consistently. Not so busy a band as, say,
Yes, for example, the concept behind
the music is to create the proper
moods behind the lyrical content.
Therefore, the mix features the vocals
up front cushioned by synthesized
strings and other assorted keyboards.
The drums are fairly subdued with the
guitar and bass basically playing the
same melodic line as the keyboard,
thereby creating a three -part harmonic
line. Although I would prefer to hear
more activity from the drums and
more diversity on guitar, it may be an
either /or situation regarding the
drums. Drummer Phil Collins now
handles all the vocals and may prefer
to downplay his percussive line in
deference to being able to do it "live."
Be that the case, it should be remembered that recording and performing
are two separate entities. Regardless,
after eight years of near misses, I'm
glad to see that Genesis has stuck it
G.P.
out and that it's paying off.
KURSAAL FLYERS: Golden Mile.
[Mike Batt, producer; Tim Friese- Green,
Bob Butterworth, engineers; recorded at
Messex Studio and Landsdowne Studio,
London, England.] CBS Import 81622.
Performance: No complaints
Recording: Veddy nice, thank you
Well, right away you're spoiled, being
that it's an import. The separations are
more pronounced, no surface noise, a
very clean production all around. Musi-
cally, the Kursaal Flyers pull surprises
like Billy Carter pulls beers. To look at
them (note the pedal steel in the group),
one would think that they're England's
answer to Dr. Hook. Let's face it, these
guys are a fun bar band, and I'd have no
problem visualizing them at the Long branch Saloon in Berkeley. That, however, is not to say that they lack sophistication. The occasional classical cliches
dropped with deference throw you
off. Strings float through songs, connecting passages and succeed in giving
them another dimension, not just filling up tracks.
When does a cliche stop being a cliche?
When it does not distract your attention
and allows you to focus on the overall.
The castanets and Spanish bullfight -type
brass add the perfect touch to "Two
Left Feet." Lyrically, they play it
straight, whereas a Dr. Hook would
71
But, all in all, there's no doubt that the
Kursaal Flyers had fun making this record, and that that fun is contagious to
the listener.
G.P.
ORNETTE COLEMAN: Dancing In
Your Head. [Ornette Coleman, producer; James Jordan and Robert Burford,
associate producers; John Snyder, creative director; Steve Goldstein, engineer,
Joujouka, Morocco, January, 1973,
Francis Maimay, engineer, Barclay Studios, Paris, France, December,
A & M Horizon SP 722.
KURSAAL FLYERS: Pulling surprises
ham it up. Straight -ahead rock is no
stranger to the Kursaal Flyers, with
"Street of the Music" being a perfect
example. With female back -up singing
the background chorus, a horn section
complementing a chunky rhythm part
to a non -distorting rhythm guitar, the
throttle is wide open for them to let
go. The odd thing about the song is the
guitar solo. It's so muddy and so buried
in the mix that it has no effectiveness.
After another vocal chorus we're
switched to it again, and this time it's
pumped up a few dB, but still to no
avail. It's so inconsistent with this recording that it must have been done
deliberately, although why is beyond
me. Vocals are separated from the backing instruments to the extent that you'd
swear you could measure the distance.
1976.1
Performance: Avant Garde but tasteful
Recording: Oui, Oui, Paris;
So-So, Morocco
Ornette Coleman's conspicuous absence
from the recording studio and the concert and club scene indicates a change of
direction, a rethinking of the player's
art. Gone are the intertwining horn lines
played with Don Cherry and Dewey
Redman over the churning rhythms of
bassist Charlie Haden and Billy Higgins.
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MODERN RECORDING
Ornette's new group, Prime Time, has
the structure of a rock band (two guitars, bass and drums) but the musical
direction will be familiar to all Omette
engineer; recorded at Paramount Recording Studios, Los Angeles, Ca.] Epic PE
34469.
effect of a volume /wah going from full
to thin. With headphones, one detects
towards the end of "Carry On" that the
right side of the mix is, in volume,
totally disproportionate with the left.
On "What Do They Really Fear?" (a
Hendrix -influenced vocal and guitar
piece) the piano sounds terrible, apparently played through a phase shifter.
The echo used on the fuzz guitar in no
way blends with the rest of what's going
down, serving only to detract from what
otherwise might've been a nice Hendrix style guitar solo.
The hand claps on "'Sense Me Miss"
need definition. The introduction of a
horn section is also damaging to the
piece because they either: a) were too
closely miked, b) peaked on the VU
meters, c) should have been redone, for
in several places the musicians couldn't
hold their notes, or d) all of the above.
The mix is the weirdest I've ever heard.
In the stereo field, the left side of
the mix -containing the drums and bass
-is so much louder than the keyboard/
guitar on the right that the listener will
be tempted to use his balance control
and maybe even an equalizer, if he has
one, in an attempt to even the balance.
The music on Side Two is more ener-
Performance: Uneven
Recording: A bit sloppy and uninventive
This is a curious recording for each
song seems to lack purpose. The current
trend among progressive jazz /rockers,
like Duke, has been to turn to the use of
vocals, which ordinarily is fine, except
that in Duke's case, one detects immediately that he has nothing to say.
George Duke's keyboard work has
taken the back seat and is making serious moves towards the trunk. Side One
is beset with the problem of having
everything geared around the vocals so,
artistically, the music serves no other
purpose than that of a bed. In terms of
ORNETTE COLEMAN: A rethinking
of the player's art
Coleman fans. The horns have been replaced by the guitars of Bern Nix (right
speaker) and Charlie Ellerbee (left
speaker). Bassist Rudy McDaniel and
drummer Shannon Jackson lay down a
beat that's more insistent and less flexible than those of Ornette's previous rhythm sections. Omette sometimes finds
himself molding his improvisations to
what the bass and percussion insist upon.
The piece which composes most of
this LP, "Theme From A Symphony,"
is from Ornette's major work, "Skies
of America." The two variations were
recorded in Paris in 1976 with no overdubbing and only an occasional rhythm
track added.
The final brief selection, "Midnight
Sunrise," is an experiment in blending
the Western music of Omette Coleman
on alto sax and Bob Palmer on clarinet
with the Eastern music of the master
musicians of Joujouka, Morocco. Although vastly different, these two subcultures improvise together without the
kind of disastrous fragmentation that
one might have expected. The recording
was made in 1973 in Joujouka where
there are no sixteen track studios available. For an album recorded on two track portable equipment, it's all right
but I wish circumstances had allowed
for more presence and definition of the
ensemble instruments.
J.K.
GEORGE DUKE: From Me To You.
[George Duke, producer; Kerry McNabb,
engineering, the LP starts out with a
clearly recorded introduction, over one
minute long, which creates a great feeling of expectation for what's to come.
But it's all for nought, as this brief period seems to be the only time the engineering is on top of things.
This record lacks an overall equal
presence level. Background vocals are
nearly inaudible, instruments are buried,
synthesizer panning reduced to the
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SEPTEMBER 1977
HII
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Anyone curious about -or already immersed in- post -Coltrane jazz should
have Anthony Braxton: The Montreaux
/Berlin Concerts. Recorded in 1975 -76,
the compositions, all by Braxton, reinforce his position as perhaps the most
provocative intellectual force in the new
music of this decade. Braxton's precise,
demanding criteria of extraordinarily
sensitive collective dynamics and his absorbing command of -textural nuances
make him the commanding presence in
all these performances. Furthermore, as
a soloist, he handles the alto, clarinet,
sopranino sax, and contrabass clarinet
with such total mastery that no anti avant -grade jazz traditionalist can accuse
Braxton of jiving on his instruments. He
knows exactly what he wants and how
to achieve it.
Yet I have a reservation. The Chicago born Association for the Advancement
of Creative Music, from which Braxton
evolved, has a motto, "Keeping `the
shout' in the music is what's all about."
The shout is the life- force, "the goat cry" (as novelist Thomas Wolfe used to
put it). Some call it "soul;" older players would talk of telling a story-with
human horns. Braxton has everything
but that shout, that visceral force. His
stories are impeccably crafted but they
are not likely to change lives -as the
tales of Bird and Pres and Trane did.
"The shout," however, is in this four sided album -from the astonishing
young trombonist, George Lewis, whose
emotions as well as ideas are larger than
life -size. And the life force is in drummer Barry Altschul and bassist Dave
Holland, among others. My sense is that
the shout is also deep inside Anthony
Braxton, and if he's ever able to let it
out, he could be the colossus of the
1980's. In any case, the album is fascinating in its continual tension between the
leader's penetrating intellectand the more
earthily imaginative souls around him.
The recording quality throughout is
superb -exceptional presence, individually and collectively. In fact, a model
of crystalline balance for all sessions of
post- Coltrane jazz.
As a further measure of the key element Braxton is thus far lacking, there
is an utterly delightful reissue set, Sarah
Vaughan, Recorded Live in sessions in
Chicago and Copenhagen from 1957 to
1963. Here is a musician -singer, with
more prodigious technical resources
than any of her contemporaries. And
while it is true that occasionally, she
delights in just stretching those skills
"showboating" it used to be called
there is in everything Sarah does a high energy, deeply swinging, soaring, exultation of the life- force. She has that inner
"shout," even when caressing a ballad;
and so, listening to her through all four
sides has a marvelously re- energizing
effect. And that too is what jazz is
all about.
Both the original recording and the
tape re- mastering keep the "live" excitement while focusing on an optimum
recorded rather than concert experience.
-
ANTHONY BRAXTON: The Montreaux
/Ber/in Concerts. [Michael Cuscuna, producer; John Temperley, Carlos Albrecht,
engineers.] Arista AL 5002.
SARAH VAUGHAN: Recorded Live.
[Robin McBride, reissue producer; no
engineering credits.] Mercury /EmArcy
Jazz Series EMS -2 -412.
602-267-0653
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MODERN RECORDING
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getic, but comes off sounding like the
quartet version of Return To Forever,
which isn't unusual since Stanley Clark
[bassist for Return To Forever] plays
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BARTOK: The Wooden Prince, Op. 13.
(Complete Ballet). New York Philharmonic, Pierre Boulez, conductor. [An-
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half the album. The overdubs,
sounding as though they were possibly
room miked for added ambience-an
unusual situation in multitrack recording -don't blend with the rest of the
side. The mix doesn't give equal time
to everything.
The one thing that can be shared
equally by all concerned is the blame
for this directionless, and pointless,
recording.
G.P.
on
13717 S. Normandie Avenue
Gardena, CA 90249
(213) 770 -2333
CIRCLE 90 ON READER SERVICE CARD
takes all the repeats-which I usually
find too much of a good thing in this
symphony -and sustains interest and
excitement throughout.
Out of forty -one recordings of the
Seventh presently in the Schwann catalogues, three superb performances on
budget labels should be mentioned for
the adventurous: Toscanini's 1936 New
York Philharmonic recording on Vic trola, Cantelli on Seraphim and Walter
on Odyssey (unfortuantely, only available in a box of all the symphonies)
the first in unadulterated mono and the
last two in good early stereo sound. S.C.
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1
BEETHOVEN: Symphony No. 7. London Symphony Orchestra, Colin Davis
cond. [Vittorio Negri, producer; recordPhilips
ed in London, April 1976.]
9500 219.
Performance Among the best
Recording: Ideal
This is the best of Davis' Beethoven
cycle on Philips so far. His early 60's
recording of the Seventh still on Angel
is a fine one, and perhaps his long
acquaintance with the work contributes
to the sense of maturity which pervades
this performance. Only Haitink, of the
younger generation of conductors who
have recently recorded this work,
demonstrates comparable mastery, and
Davis scores over him with better pacing
of the trio in the scherzo and a recording of more presence and guts. A
measure of Davis' success is that he
drew Kazdin, producer; Bud Graham,
Milt Cherin, Ray Moore, engineers;
recorded at Manhattan Center, New
York.] Columbia M- 34514.
short of phenomenal
Refined yet very natural
Performance Nothing
Recording:
Recordings by Pierre Boulez and the
New York Philharmonic, produced by
Andrew Kazdin, have been praised
before in these pages, but this is their
finest collaboration yet. In all respects
-
interpretation, performance and sonicsthis is undoubtedly one of the best
records of the year and perhaps the
finest -sounding orchestral recording on
the Columbia label.
One would not expect The Wooden
Prince (1917) to interest Boulez so. A
product of Bartok's folk -nationalist
years, lacking the Freudian introspection of Bluebeard's Castle (1911) and
the otherworldly barbarism of The Miraculous Mandarin (1919), there is nothing innovative or particularly striking
about the score. This is Bartok at his
most benign, and while the music may
seem at first a bit overlong, further
acquaintance increases one's appreciation. Not surprisingly, Boulez emphasizes the colorful orchestration, the
heavy influences of Debussy and Stravinsky (The Firebird, especially). The
dance character, breadth and affectionate rubato of his conducting makes the
fine 1965 Dorati /LSO recording (which
should be reissued on Mercury Golden
Imports) seem monochromatic and insensitive by comparison. The playing
of the New York Philharmonic is little
short of phenomenal, perfectly in tune
with Boulez's warm, elastic shaping of
the music. This record has turned on my
CIRCLE 97 ON READER SERVICE CARD
76
MODERN RECORDING
That
Good Sound
PIERRE BOULEZ: A warm, elastic shaping of Bartok
table during leisure hours more than any
other disc this year.
Having attended many of this team's
sessions I am consistently surprised that
despite close placement of the many microphones, the final perspective appears
somewhat distant and refined -never
flat and without depth, as, for example,
London's consciously blockbusting Solti
/Chicago recordings (e.g., Zarathustra,
Enigma Variations). It's all in the mix,
of course, and Kazdin won't tell his secrets. Whatever his technique, though, he
has produced a rich, warm transparent
orchestral palette, with no distracting
spotlighting. It sounds very natural
which is what it's all about.
S.C.
-
WEILL: Threepenny Opera. Raul Julia,
Macheath; Caroline Kava, Polly Peach um; Ellen Greene, Jenny Towler; Blair
Brown, Lucy Brown; C.K. Alexander,
Jonathan Peachum; Elizabeth Wilson,
Mrs. Peachum; David Sabin, Tiger
Brown; Roy Brocksmith, Ballad Singer;
horus and instrumental ensemble, Stanley Silverman, cond. [Larry Morton,
producer.] Columbia
PS
34326.
Pales by comparison to
earlier versions
Recording: Best yet sonically
Performance
WEILL: Mahagonn y Songspiel, Kleine
Dreigroschenmusik, Pantomime, Vom
Tod im Vald, Berliner Requiem, Violin
Concerto, Happy End. Meriel Dickinson,
mezzo -soprano; Mary Thomas, mezzo soprano; Philip Langridge, tenor; Ian
Partridge, tenor; Benjamin Luxon, baritone; Michael Rippon, bass; Nona Liddell, solo violin; London Sinfonietta,
David Atherton, cond. [Dr. Rudolph
Werner, producer; Wolfgang Mitlehner,
engineer.] DG 2709064 (three records).
Performance
Excellent, yet a trifle
stodgy
Recording: Among DG's best work
For devotees of the music of Kurt
Weill -and I am one -this is a time
of
boundless opportunity to appreciate
and savor his music. Recently there have
been simultaneous productions of
Happy End (written with Brecht) and
Knickerbocker
Holiday
(Maxwell
Anderson). Neither of these shows is
done frequently; in fact, Happy End has
just premiered in New York. Threepenny Opera has recently concluded a
successful run at Joseph Papp's New
York Shakespeare Festival and was revived in Central Park last summer. Finally, we have recent releases of the original cast recording of this Threepenny
Opera production as well as a three record set on Deutsche Grammophon of
much of Weill's work with Brecht,
which includes several previously unrecorded works plus music from Happy
End, Threepenny Opera and Mahagonny.
Of the five recordings in existence
which document various productions of
Threepenny Opera, three are in German
(the oldest, with original cast members
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41
from Berlin, is out of print), making the
current issue only the second English
language version on record. Therefore,
a comparison of the two is unavoidable.
The previous recording comes from
the Theatre De Lys production of 1954
and utilizes the English version of Threepenny Opera. This version, the work of
Marc Blitzstein, retains its stature since
it is at once stageworthy and reasonably
faithful to the spirit of the original. In
comparing the Blitzstein adaptation with
the Papp production, adapted by Ralph
Manheim and John Willett, there are
several considerations. Blitzstein, clever
as he is, makes no attempt to preserve
the meter of the German song lyrics
when he adapts. His versions of the
songs are singable but rather free. Man heim and Willett have tried to be more
literal, as well as singable, but with only
intermittent success. Their settings are
mainly awkward and hard to follow,
and frequently no closer to the German
than Blitzstein. Although Manheim and
Willett occasionally do significantly
better (a notable example is the "Cannon Song "), mostly they are somewhat
more accurate in translation but vastly
less performable than Blitzstein, who
was a better poet in his own right.
There are other points of consideration as well. A fair amount of the uglier,
coarser verses in the original show were
softened or deleted for the 1954 revival.
Many of these are restored for this 1975
production. Well and good, but to interrupt the self-congratulation expressed
by Mr. Papp in his notes for the album,
1975 is a much more permissive age
than 1954 was on Broadway. What had
to be censored then is no great piece of
courage to restore now. Also, the recent
production seems to have taken the attitude of smut for smut's sake.
It is hardly being prudish to point this
out, since Brecht and Weill certainly
provided their seamy moments in Threepenny Opera, but Manheim and Willett
(perhaps encouraged by Mr. Papp) seem
obsessed with providing raunchiness in
places poor Bert and Kurt never dreamed of-or desired. Examples abound, but
one very good one should suffice: in the
song which translates as "The Procurer's
Ballad" but which Manheim and Willett
call `Ballad of Immoral Earnings," there
is a line referring to an unwanted child
which Jenny at one time had by Mac heath -and the rather ambiguous disposal of it. Mr. Papp, in his liner notes,
makes a big deal about how Blitzstein
excised it and they have restored it.
However, the Manheim/Willett version is
grossly incorrect and ugly in a way
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Brecht and Weill had no interest in. The
original line is best translated by Eric
Bentley as "at that this child was destined for the rushes." This is clearly a
cryptic allusion to Moses in the Bible,
something Brecht was fond of doing.
Manheim and Willett give us this: "But
in the end we flushed it (the child)
down the sewer." Totally uncalled for
and flagrantly unfaithful. Brecht and
Weill knew that a little vulgarity goes a
long way; but Manheim and Willett
cram it in everywhere they can and
seriously weaken their accomplishment.
A word is also in order about the musical arrangements. The Papp production
ful, but not as well performed as the old
one, nor as much fun. There is a pall
about this new version that weighs it
down. Own them both if you feel so
inclined, but I'd rather live with the
previous recording.
Turning to the DG box of Kurt Weill
music: this set fills a vital gap in the Weill
discography. Focusing primarily on the
Brecht-Weill collaboration, it provides
us with several previously unrecorded
works. Dealing with material composed
between 1924 and 1928, it is a good selection of Weill's Berlin work as well as
an evidence of Kurt Weill, the serious
composer. Speaking personally, the
Label
Here
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MODERN RECORDING Magazine
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WEILL: Filling a vital gap
Robed Angus
good deal closer musically to the
published score than the Theatre De Lys
recording. However, Eric Salzman's
statement in his review of the Papp production disc, "... we have never really
heard Weill's orchestration before... ,"
is absurd. To begin with, much of the
published score was not orchestrated by
Weill at all. Weill's autograph appears on
many of the unorchestrated songs.
Many hands have interposed between
Kurt Weill and the published score, so
Weill's orchestral intentions are far from
clear. Stanley Silverman has done reasonably well in arranging his version of
the score -though it is no closer to the Universal Edition of Threepenny Opera than
is the German recording on Columbia.
If you are like me, you'll want all versions of Threepenny since it is a masterful piece of musical theatre. If you are
less obsessive, the new recording is better sonically and somewhat more faithis a
The entire six -part series from
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NIP
SEPTEMBER 1977
most enjoyable material in this collection includes the music from Happy
End and the suite from Threepenny
Opera called "Kleine Dreigroschenmusik." The Mahagonny Songspiel leans toward a more serious opera form and the
remaining works show us Weill's efforts
in such forms as the cantata, dramatic
lieder and violin concerto.
These recordings are equal to DG's
best work sonically and are provided
with a highly informative booklet which
is notable also for including Michael
Feingold's superb English versions of
the songs from Happy End and Mahagonny Songspiel. The performances are
stronger musically than any collection
of Kurt Weill's material I know of and
intelligently, if a trifle stodgily, interpreted. Whether you are an old Kurt
Weill fan (as I am) or just discovering
him, this set is indispensable.
H.R.
79
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