ecordiiì - American Radio History
MIR
$2.50
ecordiiì
FEBRUARY 1979
VOLUME 10 -- NUMBER 1
engineer
producer
The Digital Recording
age
arrives at L.A.'s
RECORD PLANT,
A &M
studios..
RELATING RECORDING SCIENCE
TO r'.ECORDING ART
www.americanradiohistory.com
TC RECORDING EQUIPMENT
Mrsatile...
the word for Everything Audio. We have a wide range of clientele because we satisfy
wide range of needs. From the most elaborate studio design and installation to the
Pictured at left is one of our
smallest equipment need, we are ready to serve you
installations, Spectrum Recording Studios in Venice,
California. Our involvement in this project was
limited to that of design -to maximize their available funds, the owners had their own builders handle
Pictured at right is Compact
construction.
Video Systems in Burbank, California, an advanced
is
a
L
illift".,
-!
audio /video facility utilizing
computer assistance in the post
production audio room. It is one
of our newest and most elaborate
installations. We designed this
facility in an existing structure,
supplied the audio equipment,
and assisted their crew during
construction, clarifying and
modifying the plans as the work
progressed. The combined effort
of the Compact Video crew and
the Everything
,
supplied the plans in metric measurements and, through local representation, kept involved in the project
until its completion. In all of our pro-
Audio staff resulted in an installation that is innovative in its technology as well as
its finish and
jects- anywhere in the world -the
home office keeps abreast of everything with on -site inspections.
If you are contemplating upgrading
or building a new facility, we'd like to
show you what we can do for you. Or
if you're just looking for a new piece
of equipment -let us help.
From
total design and installation, to supplying
the smallest equipment need -we do it all.
f-
materials
Another of our
recently completed studios is the
Record Star in Hamburg, West Germany.
(We have representation in Great Britain,
Germany, Australia, and Mexico.) We
my2
16055 VENTURA BLVD., SUITE 1001
L
DIICIZ9
ENCINO, CALIFORNIA
91436
Versatility: Let it work for you.
www.americanradiohistory.com
(213) 995 -4175
AMEK M3000
..wtateono
III
MD
.
OM
o
.rr+rrrrrrrrrrrrtrtt
Favourably comparable with any console available today, the standard 36 -input desk offers simultaneous
quad, stereo and mono mixes from 32 tracks, with DC subgrouping of VCA- assisted channel and echo return faders.
The M3000 only has excellent performance specifications and is purpose -built to allow the engineer total
control of the many advanced signal development and flow functions available in the cesk.
Some of the outstanding facilities include: one mic and two differential line inputs: 4 -band parametric
equalization (variable frequency and Q on all 4 bands) with swept pass filters: four mono and one stereo send
addressable to 8 busses: inplace, groupable quad solo: programmable and groupable muting: automation ready
VCA channel faders with LED display in 'read' mode: 8 dedicated submasters: 24 assigns with panning odd-even
between live busses, and direct assigns: additional audio subgrouping in remix: 32 track monitoring: in -line
construction: comprehensive studio and control room monitoring systems: talkback: oscillator: 8 automated echo
returns, 4 assignable to multitrack: overall status commands for main operation modes: comprehensive patchfield:
phantom power: Penny and Giles conductive plastic faders.
Also available are the M2000, our most cost- effective 24 track desk, shortly also with automation option;
the M1000, our ten buss console intended for 16-track and sound reinforcement work; the X series, our small
console useful for 8- track, broadcast and reinforcement application,
E
EIZYTHIND
Contact Brian Cornfield at. EVERYTHING AUDIO 16055 Venturo Blvd. Suite 1001, Encino, Los Angeles, CA 91436, Tel (213)995 4175.
MARTIN AUDIO
distribution. Courteney Spe.'cer or Bruce Martin, MARTIN AUDIO. 423 West 55th. New York 10019. (212) 541 5900.
AMEK SYSTEMS AND CONTROLS LTC Islington Mill, James St. Salford M3 5HW, England. Tel: (061) 834 6747.
East Coast
www.americanradiohistory.com
BUILDING A STUDIO CA
SIERRA'S EXPERIENC
Yes, it's expensive to
recording studio today - and,
unfortunately,
to become
build a
it's going
more expensive with
increases in the cost of
everything; materials, labor,
and especially the almost hidden
cost of time delays. Plumbers
and electricians can't be
expected to stand around without
...
being paid while waiting for
an on -site decision
and the costs of "working out
when we come to
can certainly be catastrophic. Once the cement
truck arrives there is no turning back.
it
it ",
We offer the kind of planning and preparation
available only from
professionals who have built
studio after studio. And,
how many times have you
heard about a room having
to be rebuilt (at even greater
cost) because of poor design?
The lesson: experts in studio
design and construction aren't found in your local equipment store, where
studio design is merely a hobby or sideline. It is impossible to build a truly
professional studio from a textbook.
Excellent results can only be obtained by using proper
materials in a proven plan.
BE EXPENSIVE
AN MAKE IT PROFITABLE.
Profit from a plan developed by the people who
build studios strictly for the professional.
KENT DUNCAN
-experience
utilizing keen insight
gained from his years of
working with
some of the world's most famous artists,
producers, and engineers, has developed a systems
approach to the technical, financial, and human
aspects of studio design. Now, you can buy the
experience that made Kendun (Sierra's best effort
to date) one of the World's best -known studios.
TOM HIDLEY
-
universally respected acoustician who has
refined the knowledge gained in evaluating the results of over 185
studios constructed from his drawings into an
acoustic environment as advanced
as tomorrow's recording techniques. And a
guaranteed design that assures your success
costs about the same as a four track machine.
SIERRA AUDIO, as exclusive representative
of Tom Hidley's acoustic design services in
North and Central America, Asia, Australia,
Japan, and the Pacific, can provide the only
acoustic design with performance
guarantee, years of construction
expertise, and business acumen to make your studio an artistic
and financial success. Whether
you're planning a new facility
from the ground up, or renovating
your present studio,
we are anxious to make you
i
part of our story.
621 South Glenwood
ieRRa
O
Place
Burbank
California 91506
Phone (213) 843 -8115
Telex 691138
We won't
promise the World,
but we will deliver what we promise!
www.americanradiohistory.com
C RDINC
engineer/producer
- the magazine to exclusively serve the
-
FEBRUARY 1979
VOLUME 10
NUMBER 1
Recording Studio market ...all those
whose work involves the recording of
commercially marketable sound.
- the magazine produced to relate ...
Contents
Recording ART to Recording SCIENCE
to Recording EQUIPMENT.
page 24
page 40
Editor /Publisher
Managing Editor
Consulting Editor
Operations Manager
Traffic Manager
Business Manager
Circulation Manager
.
MARTIN GALLAY
TOM LUBIN
PETER BUTT
D. KEITH LARKIN
KEN McARTHUR
V L. GAFFNEY
PATTY COLLINS
-
.. (TDS") Time Delay Spectrometry ..
(PZM") Pressure Zone Microphones ..
.
A HIGH PERFORMANCE, LOW -COST
page 60
TRANSFORMERLESS MICROPHONE PROJECT PREAMP
by Daue Baskind and Jon Sanserino
-
(USPS 768 -840)
page 76
page 78
page
101
IMPULSE ALIGNMENT OF LOUDSPEAKERS
AND MICROPHONES
Part II
by Gary Leo and Don Pearson
the promise of
VCAs
ELECTRONIC GAIN CONTROL
by Harvey Rubens, Dave Baskind and Marvin Caesar
Response on behalf of dbx, inc.
-
"RECORDING Engineer /Producer"
published six times a year by GALLAY
COMMUNICATIONS, INC., 1850 N. Whitley Avenue, Hollywood, California 90028,
and is sent to qualified recipients in the
United States. One year (six issues) subscriptions for other than qualified individuals and companies may be purchased at
the following rates:
United States (surface mail) .. $10.00
United States (air mall)
$17.00
All Other Countries
$19.00
Foreign subscriptions payable in U.S.
funds only by bank check or money order.
(LEDE) Live End - Dead End Control Room Acoustics
by Chips Davis and Don Davis
page 72
is
by Tom Lubin
.
page 65
J
GEORGE MARTIN Revisited
-
...
by David Blackmer
Response on behalf of Allison Research
by Paul Buff
1978 INDEX OF FEATURE EDITORIAL ARTICLES
-
The Cover
(Top photo) Mr. 'A' of A&M
with their new 3M Digital
Recording System. (Bottom
photo) Same day, 3M's John
McCracken with Record
Plant's Penn Stevens after
installation tests.
Departments:
Letters
12
--
-
108
News
18
Studio Update
88
New Products
102
Classified
o
RECORDING Engineer /Producer is not
responsible for any claim made by any
person based on the publication by RECORDING Engineer/Producer of material
submitted for publication.
Material appearing in RECORDING Enginner /Producer may not be reproduced
without written permission of the publisher.
Controlled Circulation Postage
paid at
Los Angeles, California
Postmaster: Send form 3579 for
address correction to:
THIS ISSUE OF R -e /p IS SPONSORED BY THE FOLLOWING LIST OF ADVERTISERS
AKG
92
Harrison
107,109,111,113
Quantum Audio Labs
21
Allison Research
Invonics
65
68
SESCOM
103
Altec Corporation
Interlace Electronics
5
70
Shure Brothers
bk cvi
Amek
1
JBL
61,107
Sierra Audio
2-:
Atlas Sound
33
Jensen Transformer
109
Sound Workshop
19,32,93
Audio Associates
44
Klark -Teknik
31
Spectra Sonics
10 -11,81
Audio & Design Recording .. 71
Lexicon
77
Stanton Magnetic
10f
Audio Industries Corp
29
Loft Modular Devices
91
Studer ReVox
63,10'
Audio-Technica, US
49
MCI
13
Studio Supply Company .... 5!
Audioarts Engineering
67
MXR
27
Symetrix
23
Auditronics
73
Magnetic Reference Labs ... 20
Tangent Systems
it
Auratone
MICMIX Audio Products .35,99
21
TEAC /Tascam
50-5'
BGW Systems
75
Rupert Neve, Inc
16 -17,59
Telex Communications ... 37,7!
BTX Corporation
Northwest Sound
93
39
3M Companies
2:
Rudi Breuer
103
Omnicraft
98
UREI
41
ClearCom
34
Orange County Electronics
45
URSA MAJOR
61
Countryman Associates .... 108
Orban Associates
43
Valley Audio
8!
dbx, inc.
6
Otani Corporation
46 -47,83
Valley People
81
DeltaLab Research
PML
69
96
Wakefield Manufacturing ... 10,
Eastern Acoustics
38
Peavey Electronics
53
Westlake Audio
56-5
Electro-Voice, Inc
81
OSC Audio Products
White Instruments
95
6:
Eventide Clockworks
90
Quad -Eight
9,94
Windt Audio Engineering .. 10:
Everything Audio
cvr 1
Yamaha International
2!
.
RECORDING Engineer /Producer
P. O. Box 2449
Hollywood, California 90028
(213) 467-1111
R-e/p 4
www.americanradiohistory.com
IF YOU THINK
ALTEC LANSING ONLY MAKES
GREAT SPEAKERS...
ALTEC
Al TFC
i
O.4
OOOOOT
1
,OLUML
...Meet The read Pow it Behind Them.
At Altec Lansing, we've been making high -quality
loudspeakers for over forty years. And we're very
proud of the reputation that they've earned during
that time. But perhaps it's because we're so well
known for our speakers that some people tend to forget that we also make a full line of professional electronics. Equipment that's built with the same quality
and reliability that our speakers are famous for.
Case in point: The Altec Lansing 9440A power
amplifier.
The 9440A is a dual -channel power amp that delivers
the high performance standards that today's audio
professional needs. It produces more than 200 watts
per channel into 8 ohms of highly reactive loudspeaker load. At 4 ohms the power is typically greater
than 400 watts. And even at these levels the 9440A
has less than 025% THD or IM distortion and a frequency response that's flat 0.25 dB from 20 Hz to
t
20 kHz.
Of course high performance must be matched with
high reliability. The 9440A is designed to meet the
most demanding conditions. Day- after -day. Year -afteryear. Reliability provided by sixteen 250 -watt home-
ALTEC
LANSI NG
llr,d,U,
I
taxial power transistors backed up by a massive die cast aluminum heat sink. Reliability ensured by an
efficient VI limiter, a unique 40% power- limiting circuit
and an output relay that protects against dangerous
turn -on /turn -off transients. Reliability good enough
to earn both UL and CSA approval.
And because we think that an amplifier should do
more than just amplify, we've incorporated some features in the 9440A's design that will help make life a
little easier. Features like lighted VU meters, meter
range switches and provisions for adding plug-in input
transformers. Features like a front- panel -mounted
switch that converts the 9440A into a single -channel
amplifier with a true balanced output. Features that
help make the 9440A a versatile addition to any
sound system.
But perhaps the best feature of the 9440A is that it's
from Altec Lansing -a leader in quality audio products
for over four decades.
So if you're thinking about power amps, think about
Altec Lansing. Check the Yellow Pages under Sound
Systems for the name of your local Altec Lansing
sound contractor. And meet the great power behind
our speakers.
1515 So. Manchester Ave., Anaheim, Ca. 92803.714/774 -2900
AI:11 :C
CORN /RATION
tor additional information circle no.
1
www.americanradiohistory.com
HUSH MONEY.
The dbx 208 tape noise reduction system is a new
product that will impress both your engineering
staff and your accountant. The 208 features 8
channels of simultaneous noise reduction on plug -in
modules, plus a spare, all in a compact 51/4" rack
mount package.
dbx noise reduction is rapidly becoming
the new industry standard because it provides 30 dB
noise reduction and 10 dB headroom improvement,
from 20 Hz to 20 kHz, without the problems of other systems.
The dbx system does not require critical and time- consuming
level -match adjustments. Its true RMS detectors are not sensitive
to tape recorder phase shift. Its voltage -controlled amplifiers
(VCAs) operate over a 100 dB range. Overall the dbx system
provides a level of performance and a simplicity of operation
that is unsurpassed.
But the 208 is also a great value. It is priced at $3300.
That's $6600 for your 16 -track and $9900 for your 24-track.*
And no matter how complex the future becomes, the 208 system
expands simply and economically.
The dbx 208. The easy solution to your noise
problems, today and in the future.
dbx, Incorporated,
71 Chapel Street
Newton MA 02195
617 -964 -3210
UNLOCK YOUR EARS
r
-1T
'Nationally advertised value.
Actual prices are set
by dbx dealers.
for additional
.rmation circle no.
www.americanradiohistory.com
2
S6CO 3l,D
°
10.4
RODER SERVICE CARD
USE THIS CARD FOR MORE FACTS ON ITEMS SEEN IN THIS ISSUE
Titi1
Name
Company
Address
City
Zip
State
I
l
1
1
1
1
PLEASE CHECK APPROPRIATE CATEGORY:
4) Which of the following describes the functions you regularly
Oyes ONO
you personally?
2) Are you professionally involved with
magnetic recording?
Oyes ONo
3) Which of the following best describes your primary relation ship to the professional audio business? (Circle One)
O Sound Reinforcement
O Recording Studio
O Producer
O Sound Contractor
1)
Wu this copy addressed I.
perform?
Owner 'Manager
O Mixer
O Maintenance Engineer
O Video. Movie Recording
O Production Quantity Tape
Other
O Producer
O Disc Cutter
Recording
Reinforcement
Duplicating
O Remote
O Sound
OOther __
SEND INFORMATION ON ITEMS CIRCLED BELOW:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
39
40
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
86
87
88
89
90
91
92
93
94
95
96
97
98
99 100
110 111
112
81
101
82
83
84
102 103 104
85
105 106 107
108 109
113 114 115 116 117 118 119 120
FIRST CLASS
Permit
No. 59188
Los Angeles CA
BUSINESS REPLY MAIL
No Postage Stamp Necessary if Mailed in the United States
Postage
will
be Paid by
O `WDIHO
er/ producer
BOX 24880'
LOS ANGELES, CA 90024
Please Note: This address is for Reader Service only.
Address other correspondence to P.O. Box 2449, Hollywood, CA 90028.
www.americanradiohistory.com
From Quad /Eight:
The forty by forty,
totally modular,
fully automated,
feature -packed,
super-spec'd,
recording and mixdown system
that you thought you couldn't afford.
/
The way you've always heard it shoui.be.
00
0.
``'',,r,,,``'',,
r.
tihoin M Coronado Mod/4 Mti4024CX
Artist In Every Engineer
/Eight Electronics
Quad/Eight International
11929 Vote Street. North Hollywood. California 91605
(213) 764-1516
www.americanradiohistory.com
Telex. 662 -446
NEW!
A NEW
"STATE OF THE ART"
DC POWER AMPLIFIER .. .
from SPECTRA SONICS,
the pioneer and leader in bi, tri, quad, and
five -way professional amplification
systems!
As the most experienced manufactur-
er of multi -way amplification systems,
SPECTRA SONICS has consolidated over
seven years of field experience into the
design of a second generation DC modular
power amplifier, the Model 701.
With such improvements as increased
power output, lower noise, higher
damping factor, LED fuse indicator, and
less susceptibility to physical abuse, the
new Model 701 warrants consideration as
the most advanced power amplifier
available today.
E
A
D
E
R
3750 Airport
SPECTRA SONICS Model 701 Power
Amplifier, it just might mean that you are
missing the privilege of listening to the
best. For complete specifications, see your
Professional Audio Dealer, or contact:
SONICS
SPECTRA
L
If you have not heard the new
I
N
Road
A
D
V
A
N
C
E
D
Ogden, Utah
T
E
C
84403
www.americanradiohistory.com
H
N
L
G
Y
(801) 392 -7531
SPECTRA SONICS modular DC power amplifiers have been utilized by such top
performers* as Paul Anka, The Carpenters, Earth, Wind & Fire, The Jacksons, Wayne
Newton, Donny and Marie Osmond, Debbie Reynolds, and by such prestigious
performing arts facilities* as Concord Pavilion, Denver Symphony Hall, Harrah's Club
Tahoe, Hollywood Bowl, Ontario Place Forum, Scottsdale Center for the Arts, Stardust
Hotel, and St. Louis Municipal Opera.
Now you, personally, may listen to the new SPECTRA SONICS Model 701 Power
Amplifier in tri- amplified systems at any of the following participating SPECTRA
SONICS dealers:
ACCURATE SOUND CORPORATION
114 5th Avenue
Redwood City, California 94063
EXCEL AUDIO
1819 Crook Avenue
Cheyenne, Wyoming 82001
(415) 365 -2843
(307) 638 -6433
AMERICAN ELECTRONICS
313 South 36th Street
Phoenix, Arizona 85034
JEFFERSON AUDIO
9701 Taylorsville Road
Louisville, Kentucky 40299
(502) 267 -9658
(602) 275 -5496
AUDIO CONCEPTS, INC.
7138 Santa Monica Boulevard
Hollywood, California 90046
KLOPF AUDIO /VIDEO COMPANY
3381 Successful Way
Dayton, Ohio 45414
(513) 236 -5500
(213) 851 -7172
AUDIO INNOVATORS
216 Boulevard of the Allies
Pittsburgh, Pennsylvania 15222
(412) 391 -6220
MULTI -SONUS, INC.
168 Durnan Street
Rochester, New York 14621
(716) 544 -8024
BARATH ACOUSTICS, INC.
1925 South Rosemary, Suite C
Denver, Colorado 80231
(303) 750 -6474
SOUND SYSTEMS, INC.
10254 Page Industrial Boulevard
St. Louis, Missouri 63132
(314) 428 -1033
CABLE BROTHERS, LTD.
7915 Argyll Road
Edmonton, T6C 4A9, Canada
SPECTRA SOUND PRODUCTS, INC.
2245 South West Temple
Salt Lake City, Utah 84115
(801) 467 -2842
(403) 465-9731
COLLMUS SOUND, INC.
627 North Bend Road
Baltimore, Maryland 21229
UNITED AUDIO RECORDING
8535 Fairhaven
San Antonio, Texas 78229
(512) 690 -8888
(301) 747 -6339
*Partial Listing Only
SPECTRA
SONICS
A
3750 Airport
Road
for additional information circle no.
D
V
A
N
C
E
D
Ogden, Utah
84403
4
www.americanradiohistory.com
(801) 392 -7531
\M\C\%\
Professional
Recording Equipment.
Available through these
dealers:
Lcttcr5
USA.
from: Brad S. Miller
*California, Hollywood
Audio Industries Corp.
"California, San Diego
Pacific Recorder and Engineering
Connecticut, Stamford
AudioTechniques Inc.
Florida,
N. Miami Beach
Recording Studio Equipment Co.
Illinois, Pekin
Milam Audio Corp.
Minnesota, Minneapolis
Sound 80
Tennessee, Nashville
Audio Consultants
Texas, Austin
Southwest Professional Audio
Worldwide:
Africa,
Rep. of S., Johannesburg
Vitaphone Pty. Ltd.
Argentina, Buenos Aires
Platten S.R.L.
"Australia, S. Melbourne
Klarion Enterprises Pty. Ltd.
Belgium, Dilbeek
N.V. Trans European Music S.A.
Brazil, Sao Paulo
Intersom
Columbia, Bogota
Ingeson, Ltda.
England, London
MCI, Ltd.
France, Paris
Studio Equipment S.A.
* Germany W., Hamburg
R.
Barth KG
Holland, Eindhoven
Pieter Bollen Geluidstechniek b.v.
Italy, Milano
Roje Telecomunicazioni S.P.A.
'Jamaica W.I., Kingston
Professional Sound Equipment
* Japan, Taito -Ku, Tokyo
Continental Far East Inc.
Korea, Seoul
Yushin Company Inc.
Malaysia, Kuala Lumpur
Dagang Teknik SDN.BHD.
Mexico, Mexico D.F.
Audio Y Consultoria
New Zealand, Wellington
Cepak Automation Ltd.
Peru, Lima
Schleusner, Heinz O.
Puerto Rico, Old San Juan
Hope, Bennet, Blackburn Inc.
'Spain, Barcelona
Singleton Productions Inc.
'Sweden, Goteborg
Tal och Ton A.B.
*Taiwan, Taipei
Phoenix & Co. Ltd.
\M\C\\\
4007 N.E. 6th Avenue
Ft. Lauderdale, Florida USA 33334
Phone: (305)566.2853 Telex: 51-4362
President/Executive Producer
Mobile Fidelity Sound Lab
Olympic Valley, CA
fascinating interview with Geoff
Emerick (R -e /p, December, 1978 by
A
Howard Cummings.) Now,
if
we could only
convince every producer and every
engineer, that sound engineering practices
will contribute more to the quality of their
final product than all of the gimmicks and
gadgets combined, the need for noise
reduction systems (in most cases) could be
eliminated altogether.
It is a sheer delight for us to receive an
original stereo master tape recorded at 30
ips, no limiting, compression, mastering EQ
or noise reduction encoding, for half -speed
audiophile mastering.
While our approach cannot accommodate the mass media market, due to AM
radio and large volume pressing requirements, there certainly is a growing need for
the alternate approach. Speaking from a
purist point of view, I hope that producers
and engineers will prepare two stereo
master tapes, simultaneously mixed of
course, with one of the masters destined
solely for "audiophile" quality mastering and
pressing of limited quantities.
In this way, we can accommodate
producers and engineers such as Geoff
Emerick, where those music fans with the hifi systems to match, can truly hear and
appreciate what was actually recorded,
rather than some facsimile made to
accommodate KHJ or WLS.
Thanks again to Geoff and Howard!
from:
Peter Butt
Audio Diagnostic Measurements
Los Angeles, CA
The article entitled "Impulse Alignment of
Loudspeakers and Microphones," by Don
Pearson and Tom Lubin, contained some
techniques that I found quite valuable in the
examination of sound reproduction systems
that I had previously taken for granted.
In the course of my experiments with
Mssrs. Pearson and Lubin's methods, it reoccurred to me that the relative phase and
polarity of the various components of the
audio signal chain are not the only matter for
serious consideration. As has been apparent
to others, Doug Sachs and Richard Heyser,
to name two, the absolute polarity of the
signal paths have a very significant impact
on the acoustic experience of reproduced
sound. Anyone having doubts about the
audibility of differences in absolute signal
polarity is invited to invert both pair of
R-e/p 12
www.americanradiohistory.com
speaker leads of his sound system and
compare percussive program material in the
inverted and erect polarity conditions.
As far as I am aware, there are no
standards whatever for conventions
concerning what response any audio system
or component shall have to a positive -going
transition. There are none for analog
magnetic recorders and reproducers; none
for disk mastering systems, phonograph
reproducers, long distance transmission
lines, broadcast transmitters, broadcast
receivers, or amplifier components. The
relative phase for the stereo or quad
channels is a matter of standard convention.
Conventions for preserving the absolute
polarity of the audio signal chain have
somehow escaped attention by standardizing organizations until even now.
I propose to the audio community at large
that the possibilities of establishing some
such absolute polarity convention be
considered as well as methods and devices
for determination that any polarity convention is, in fact, adhered to.
The areas requiring particular attention
are the electrical /acoustic, electrical/magnetic, and electrical /mechanical interfaces
in the audio signal chain.
Until some universal conventions are
adopted, I suggest that all serious audiophiles install polarity reversing switches in
their program channels as Doug Sachs has
at the Mastering Lab.
I commend Mssrs. Pearson and Lubin on
a useful and thought provoking contribution. I'm looking forward to the second part
of their discussion and hope they will include
a description of the computer program they
use to characterize their clients' audio
systems.
from: Bruce Lowell
Helen Rowe & Associates
West Los Angeles, CA
In reference to the article The Agony of
Success, (locating a new studio), in the
December issue: As a person who is
primarily involved in real estate and also has
done consulting in numerous recording
projects, I can personally relate to the
agonizing problems Mr. King faced because
I have had to find specialized facilities for
former clients.
I have also faced problems with leased
facilities for my own 4 -track studio, because
they were meant for various other purposes.
My commendation to you, Mr. King, for
holding out to find perfection.
-
continued overleaf
NIGHTWATCH
KENNY LOGGINS
ON COLUMBIA RECORDS
PRODUCED BY
ENGINEER
BOB JAMES
JOE JORGENSEN
JOHN PACE
WITH
RECORDED AND MIXED AT
SOUNDMIXERS NYC
A
TAPPAN ZEE PRODUCTION
4007
N.E. 6th
AVE. FT. LAUDERDALE, FLA. 33334
www.americanradiohistory.com
Your original sound
is at the nearest
Tangent Dealer!
from: Bert Frilot
Manager & Chief Engineer
Gilley's Recording Studio
Pasadena, TX
The letter in the December, 1978 issue
from Mr. Jack Hunt, Mastering Engineer for
Alshire Mastering Studios, is typical of the
attitude of most mastering companies. He
states that, "To make a disk that is identical
a good master tape is not really a
challenge."
How can he justify a statement like that?
Mr. Hunt states, "Make a record better
than the master tape." What is better? Is
there a published book that states the rules
as to what is better? Of course not! "Better"
is entirely up to an individual. Why should
anyone, completely detached from the
producer and the studio engineer, take it
upon himself to make the record "better"
than the tape. He can make it sound
different, but is it better, just because he
thinks so!
Why do we spend hours and hours getting
the sound the producer, or customer wants,
just to have it changed by the mastering
company? Any mastering company can
make a record sound different, (most do),
but it takes one hell of an engineer and good
equipment to make the record sound just
like the tape.
I've been a recording engineer for 17 years
and I have certainly done a number of what I
consider "bad" sessions, but the customer
left with what he wanted and was happy.
I have cut master records for about four
years, so I can appreciate the problems, but
if I could make the record sound like the
tape, no one could complain. If, however, I
was asked to do what I could to better the
tape, then fine! Then they were accepting
my ear and capabilities.
My problem as a studio engineer and
producer (9 million sellers and 26 top ten
national records) is getting my sessions on
record just as it sounds on the master tape. I
spend hours working on tones and levels,
only for someone to decide on their own that
they are going to make it "better."
I don't appreciate it, and ask any other
studio engineer or record company what
they think and Mr. Hunt will find that all of us
will shop for the mastering comany that
makes our records sound like our tapes
good, bad, or indifferent.
with
Martin Audio
New York /(212) 541 -5900
Bruce Martin
Express Sound
California (Southern) /(714) 645 -8501
Jerry Smith
Banana's At Large
California (Northern) /(414) 457 -7600
J.D. Sharp
Lebow Labs
Massachusetts /(617) 782 -0600
Peter Engle
Creative Audio
Tennessee /(615) 331 -3247
Allen Rumbaugh
Paul Westbrook Audio
Texas /(512) 578 -4401
Paul Westbrook
E.A.R.
Arizona/(602) 968-8675
Mike King
B.S.C.
Illinois /(312) 453 -5551
Paul Bergetz
Sedco
Missouri/(417) 883 -6373
Mark Morton
Pro Audio Seattle
Washington /(206) 622 -6984
Craig Ingle
Stereo Sonics Laboratories
Florida /(305) 831 -2575
Allan Smith
AVC Systems
Minnesota/(612) 729 -8305
John Borman
Listen Up
Colorado /(303) 778 -0780
Bill Rollin
-
Ford Audio
Oklahoma /(405) 525 -3343
Jim Ford
Arnoldt Williams
Michigan /(313) 453 -6586
John Williams
Veneman's
Maryland /(301) 762 -5100
An Fantin
tangent
0
Because of scheduling problems, Ray
Kimber, author of "Speaker Wire" in the
October, 1978 R -e/p, was unable to respond
to points raised in letters by Ken Dickensheets and Henry L. Brooks published in the
December, 1978 issue.
reply from: Ray Kimber
First of all, let me say that I'm a bit
perplexed that anyone can take a strong
position on a product without ever being
R-e/p 14
www.americanradiohistory.com
exposed to the said product. To my
knowledge, neither Mr. Dickensheets nor
Mr. Brooks have ever purchased or asked
for a sample of the braided cable with fine
pure copper conductors that I wrote about.
In responding to the published comments,
let me focus on Mr. Dickensheets' letter,
which was the longer, more involved and
covered the same points as Brooks.
Regarding the parameter of DC resistance in the damping factor formula, let me
say it was left out on purpose. It's an
erroneous assumption that the DC resistance at the voice coil greatly affects
damping.
The damping factor is only useful at the
time when a speaker is acting as a generator
for those of you not familiar with this
phenomena, let me explain. Anytime the
cone of a speaker is moving away from
center, it is acting as a motor with the
voltage being supplied by the amplifier.
When the cone is moving from one extreme
of excursion toward the center (the opposite
direction), then it's acting like a generator
and the amplifier should act like an electromagnetic brake by applying a short.
Damping factor is the ability of the amp to
present a short to the speaker at the time the
speaker is acting as a generator.
The voltage that the speaker produces is
determined only by the number of turns, the
strength of the magnetic field, and the
velocity of the voice coil. The resistance of
the voice coil determines how much power it
will produce at those voltage levels and
nothing else. For instance, if you were to
have a voice coil with, say, 100 turns of #20
and another voice coil with 100 turns of #40,
they would generate virtually identical
amounts of voltage, if they were moved in
identical magnetic fields at identical
velocities. The only difference would be the
amount of power available; the 100 turns of
#20, obviously, has lower source impedance
and, hence, will match a lower impedance
termination. So one can use the voice coil
resistance or voice coil impedance, but not
both in the same formula. I chose to use
impedance since that information is more
readily available.
One additional significant point is in order
about the damping factor formula used by
Mr. Dickensheets. The copper voice coil,
such as the one used in his example, will
increase in DC resistance at a rate of .22 per
cent for every degree Fahrenheit increase in
temperature. The example he uses states
6.5 ohms resistance. That value is valid only
at room temperature. Since the temperature of the voice coil will rise to in excess of
200 degrees Fahrenheit at normal operating
levels, a doubling of the resistance is
predictable. This, obviously, invalidates the
formula in "real world" applications.
...
...
continued on page 107
-
Why settle for a copy ..
Why settle for an
imperfect copy of your
sound, when Tangent will
give you the original?
Tangent's crystal -clear
transparency allows your original sound to flow cleanly to the
tape, with only the coloration
that you add.
And beyond this foundation of
solid quality, Tangent invites
comparison on these features:
Automation
Automation from Tangent uses the
innovative and widely - respected
Allison 65K programmer and Fadex
designs. Tangent chose the Allison system
because it is the proven -in- the -field system.
VCA Grouping
For those not needing full automation,
Voltage Controlled Amplifier (VCA) Grouping utilizes up to nine VCA groups,
while other manufacturers normally
use fewer.
.
when
Tangent
gives you
the original?
Sub -Group Solo
Programmable Sub -Group Solo allows the
engineer to solo an entire sub -group in
place by pushing only one button. This
convenience is not found in all competing
VCA grouping or Automation systems.
Semi -Parametric EQ
Three -band sweepable frequency equalization on each channel is a standard Tangent
feature. Not an expensive option as with
some competing systems.
Transformerless Balancing
Transformerless Balancing keeps your
original sound pure with incredible
transient response. Noise is within 3 dB
of the theoretical limit
Transformerless Balancing is suddenly a
big deal among the other console
manufacturers. It should be. Tangents
been doing it for years.
16 Submasters
Tangents 16 submaster busses plus
"Direct" allow tremendous flexibility for
or 24 -track work.
16
FET Switching
Electronic FET switching silently
rearranges the signal flows for maximum
convenience and minimum repatching.
Lots of Extras
Penny & Giles faders, multiple Echo and
Cue send, Phase Reverse, Tape Return
Gain, and many other features on
each channel give full professional control
and reliability.
Compare Tangent's features to
consoles costing twice as much
and you'll see what a value
Tangent is.
As for comparing Tangent's
quality, well, you just can't get
better than the original.
Tangent Model 3216
rongent
MUSICAL.
o
FJYGINEERI YG
2810 South 24th Street/(602) 267 -0653
Phoenix, Arizona 85034
for additional information circle no.6
www.americanradiohistory.com
R -e /p 15
The Neve Model 8088.
The ultimate music recording console with
in -line monitor. 44 inputs/32 tracks.
Designed and built to the highest standards.
Neve console,
tern Sound
d Sc.B8, at
at Eastern
ée"stud
qronto.0 c
tern and the
eve: Join
e upped
in the eve world
-
s
4
oer leadiros
ge;axEeitteií ry.
L;lßase ra l f fir write
1
-
.`+
+44'4!
tP/
\t,
&&&&&&&&
r
II
15;0VP.**151ir".46r.A506.
g
_
rts 'twits itf,
v`
al pi
I,
100".","fitrispfispArinr"rineNNic.
-
Rupert Neve Incorporated, Berkshire Industrial Park,
Bethel. Connecticut 06801 Tel (203) 744-6230, Telex 969638
Rupert Neve Incorporated, Suite 609. 6255 Sunset Blvd.
Hollywood, California 90028 Tel (213) 465-4822
Rupert Neve of Canada. Ltd 2717 Rena Road.
Malton, Ontario L4T 3K1. Canada Tel (4161 677-6611
Rupert Neve 8 Company Ltd Cambridge House,
Melbourn, Royston, Hertfordshire.
SG8-6AU England, Tel (0763) 60776
Rupert Neve GmbH, 6100 Darmstadt Bismarckstrasse 114
West Germany. Tel (06151) 81764
,
.
I
www.americanradiohistory.com
N Neve
l
SOUNDMIXER STUDIOS (NYC) complementing its facilities for record recording has installed new equipment
as a film post -production studio, according to HARRY HIRSCH, president. A Dolby /BTX/
2 to enhance its capability
SMPTE code package consisting of generator, synchronizer, reader and microprocessor /programmer has been
o installed. "In essence, it means that Soundmixer may now function as a film -post -production center, complete
with Capstan Servo and SMPTE interlock," explained Hirsch.
ÿ
STUDIO 0741 (Philadelphia) has been established by the MUSICOR Entertainment firm. Equipment includes an
eight track TEAC/Tascam recorder, a four track Toshiba, a Sony 2 -track machine with other equipment including
AKG and Shure microphones, Ashley Audio parametric equalization and peak limiting, and dbx noise reduction.
2539 E. Columbia Avenue, Philadelphia, PA 19121. (215) 763 -0741.
HALLMARK FILMS (Owings Mills, MD) formerly a 4-track studio specializing
in film scores and audio visual shows, announces its expansion to a new 7,000
square foot, 16 -track facility. New equipment includes an Ampex 1200, 16 -track
recorder, Op -Amp Series Il console, EMT 140 reverb, Scully 280 -B mixdown
machines and JBL monitors. The new facility also includes a 2,000 square foot
drive -in film stage. 51 -53 New Plant Ct., Owings Mills, MD 21117. (301) 363 -4500.
r
R,
4,
s
CRITERIA (Miami) is putting the finishing mixes on the OSMOND BROTHERS new LP with MAURICE GIBB and STEVE KLEIN producing. Klein is
also the engineer for the album with MIKE GUERRA assisting. Other groups in
the studio include the ALLMAN BROTHERS, with TOM DOWD producing and
(
STEVE GURSKY engineering, the HENRY PAUL BAND and FOXY. Criteria
also announced the naming of RON and HOWARD ALBERT, best known in the
recording industry for their production success with CROSBY, STILLS AND
NASH, as vice presidents of Criteria Recording Studios.
on
BEE JAY RECORDING STUDIOS (Orlando, FL) is recording GODDO, a Toronto -based group, now working
their third album for Polydor. Produced by GREG GODDO, this album is being engineered by TIM SADDLER with
BILL VERMILLION assisting. Also at Bee Jay are AL NALLEY and HENRY WECK (drummer of Brownsville Station)
mixing BLACKFOOT for an upcoming ATCO release. 5000 Eggleston Avenue, Orlando, FL 32810. (305) 293 -1781.
-
ECHO SOUND STUDIO (Pensacola, FL) started off the New Year by adding a
16 -track recorder to its facilities. The studio has been operating over six years
first as a four -tracker, then eight and now sixteen. A variety of recording pack-
ages are available, according to RANDY SHELNUT. All tracks are equipped with
dbx noise reduction and Echo Sound offers a plate echo unit, Yamaha grand
piano, Rhodes, and Wurlitzer electric pianos, and Yamaha drums. Route 3, Box
194 T -15, Pensacola, FL 32504. (904) 477 -6391 or 453 -2051.
SOUND 80 (Minneapolis, MN) has released the first two albums recorded
using 3M Company's new Digital Mastering System. The albums are by the
SAINT PAUL CHAMBER ORCHESTRA and the jazz group, FLIM AND THE
THE BB'S. The studio used the digital prototype experimentally as backup
during several direct -to -disk recording sessions. The prototype produced
digital tapes from these sessions were judged superior to the direct -to-disk
masters and the digital albums resulted. 2709 East 25th Street, Minneapolis, MN
55406. (612) 721 -6341
E
c
KAJAC RECORDING STUDIOS (Carlisle, IA) LEE MACE, owner of Lee Mace's Ozark Opry, Osage Beach,
Missouri, announced the purchase of Kajac Record Corporation, which includes the firm's 16 -track recording
studio facility. The purchase includes land, building, recording equipment, two music publishing companies and
record distribution company. The 16-track recording studio will continue to operate in Carlisle until a new studio
Record
complex is completed at the Ozark Opry in the Spring of 1979. HAROLD L. LUICK, past president of Kajac
in
charge
will
be
and
complex
recording
Inc.,
the
Ozark
Opry,
Corporation, has been appointed general manage of
989
-0876.
(515)
IA
50047.
Carlisle,
First
Street,
115
operations.
and
publishing
of all recording
have you?
Increased track capacity - gone 24, 16, 8
won awards
added key people
moved or expanded added important equipment
these are the interesting news items that can be announced in the next
available issue. Write:
R -e /p STUDIO UPDATE
Box 2449, Hollywood, CA 90028
R-e/p 18
www.americanradiohistory.com
After spending so much money on a state of the art
digital delay, why must you still use a tape deck
when you need more than 300 milliseconds?
Because even today's state of the art digital signal
processors are restricted.
Introducing the Shared
Access Memory System. by
Audio Machinery. The
Shared Access Memory
System is a modular
computer controlled system
that takes away the
restrictions from digital
signal processors.
The Shared Access
Memory System consists of
a mainframe and up to 8
plug in modules. The
mainframe houses the
Random Access Memory
(RAM) and a computer that
allows you to control the
distribution of the RAM
space to suit any particular
processing requirements.
The mainframe comes with
400 milliseconds of RAM,
however up to 6,000
milliseconds (6 seconds), may
be installed.
The mainframe accepts up
to 8 plug in modules. Each
module has one or more
designated functions
including: Delay, Pitch Shift
with Delay, Reverberation
and Output. The modules
determine the in/out
configuration. The
maximum delay time is only
restricted to the amount of
RAM available in the
mainframe. And with a
possible six seconds
available, that's not much of
a restriction.
Shared Access Memory
achieves 16 bit resolution,
which means it is cleaner and
quieter than the others. No
level! Proprietary algorithms
are employed which allow
the Pitch Shift Module a new
level of performance.
The Shared Access
analog techniques such as
Workshop Professional
Audio Products, Inc. For
more details please see your
professional audio dealer or
contact us directly.
companding or
pre/de-emphasis are
employed, which means that
the 16 kiloHertz bandwidth
of Shared Access Memory
is 16 kiloHertz. even at full
Memory System
is
manufactured by Audio
Machinery and is distributed
exclusively by Sound
The Audio Machinery Shared Access Memory System
distributed by Sound Workshop Professional Audio Products, Inc.
1324 Motor Parkway Hauppauge, New York 11787/516 -582 -6210
for additional information circle no.
7
www.americanradiohistory.com
R-e/p 19
JACK CLEMENT RECORDING STUDIO B (Nashville) recently re- opened after a two -month shutdown. DeÇ signed by TOM IRBY, of STUDIO SUPPLY COMPANY, and directed by Clement manager JIM WILLIAMSON,
(j Studio B underwent complete renovation and remodeling to expand its facilities from 16 to 24 tracks. New equipment includes a 28- input, 32- output Harrison console with the new transformerless mike preamps, a 24-track
Studer tape machine with 16 -track capability, 24 tracks of Dolby noise reduction, a Studer mixdown machine and
THE -1 monitors. DOLLY PARTON, DON WILLIAMS and PAL RAKES have already been in to use the new facility.
3102 Belmont Boulevard, Nashville, TN 37212. (615) 383-1982.
á
TRACKING STATION (Nashville) A 24 -track Studer with dbx noise reduction and a Sphere 40 -in, 40-out console
have been installed at the Tracking Station, a just -completed facility built by country /pop artist RONNIE MILSAP.
VALLEY AUDIO did the design work and RUDI BREUER supervised the construction. One interesting feature is a
string loft above the control room, according to BEN W. HARRIS, chief engineer. The Tracking Station is accepting
no outside bookings at the present time. 12 Music Circle South, Nashville, TN. (615) 256 -7575.
MOUNTAIN EARS RECORDING (Boulder, CO) has recently updated to 24 -track MCI electronics. Studio
engineer
JOHN ALDRIDGE describes space at the studio as "substantial," with a control room measuring 22' x 22'
c
Ears' facilities also include a drum booth, a
ó by 10' and the main "live room" measuring 50' x 60' x 22'. Mountain
separate anechoic type isolation booth and a remote listening lounge. Outboard equipment is by Orban, Marshall,
UREI and dbx. Monitors offered include JBL 4333 and 4311 as well as Auratones. Box 2240, Boulder, CO 80306.
(303) 444 -3277.
SEA -WEST STUDIOS (Seattle, WA) has added a second Ampex MM -1200 16 -track recorder, which has been
3sync- locked with their original 16 -track Ampex machine using the BTX /SMPTE time code generator and syncronizer. The first project in the new format is the new HEART LP, "Dog and Butterfly," according to RICK
° KEEFER, president and chief engineer. 319 North 85th Street, Seattle, WA 98103. (206) 783 -2524.
D OVERLAND RECORDING STUDIOS (Costa Mesa, CA) owner /producer PAUL FREEMAN announced the installation of an MCI 24-track recorder along with a Sound Workshop Series 1600 at Overland Recording Studios, a
3
-c division of Freeman & Haws, Inc. Joining Freeman as co- owners are former KITS radio producer, MICHAEL
5 ANTHONY, and TONY BRITO, former producer for HERB ALPERT in Madrid. Anthony has been named director of
`R promotion and Brito will collaborate with Freeman as co- producer on current projects being prepared for their
in -house label. The studio also accepts outside clients. 3176 Pullman Avenue, Suite 123, Costa Mesa, CA 92626.
(714) 957 -1466.
A &M STUDIOS (Los Angeles) has completed the installation of its new 3M Digital Mastering System. A&M was
chosen as one of four studios throughout the country to receive the first digital recorders marketed by 3M. The
system consists of a 32-track digital recorder and a complementary 2/4 track mastering recorder. A preliminary
session took place on February 8th, and regular sessions are scheduled to begin almost immediately with A&M's
HERB ALPERT considering the possibility of cutting a digital LP to be released on A&M Records. 1336 N. La Brea
Avenue, Hollywood, CA 90028. (213) 469 -2411.
- continued overleaf
What
isyzasre
ytu
3e
For a catalog and a lust of over 60
dealers un the USA and Canada, contact
J
G.
ldayt McKnight
MRL Calibration Tapes are designed and
supported by experts in magnetic recording
and audio standardization ... we helped write
the standards. Each tape comes with
detailed instructions and application notes.
The MRL catalog includes tapes for all studio
applications. In addition to the usual spot
frequency tapes, we make single -tone tapes
rapid -swept frequency tapes, wideband or
1 /3rd octave -band pink random noise tapes
and difference -method azimuth -setup tapes.
Most are available from stock.
IdBI
NerIcJ11
at
Inc.
Magnetic Refe
229 etic Ave ce laboratory.
Mountain View, CA 94043
lape
(4151965-8187
Exclusive Export Agent: Gotham Export Corp, o
New York, NY
1
R-e/p 20
The MRL Calibration Graph is your proof of
the quality control that goes into every MR L
Reproducer Calibration Tape. We guarantee
each one to exceed the performance
requirements of IEC, NAB, AES, and EIA
Standards.
V aloe rn
r,
for additional information circle no. 8
www.americanradiohistory.com
Quincy Jones knows quality
NOW
THERE ARE FIVE LITTLE AURATONES
Same clean sound, but five different configurations
for your special professional requirements.
5C
..
.. .
.
5PC
5S
5RC
RECORDING MONITORS FOR
AURA-TONE
CORPORATION
P.O. BOX 698
THE REAL WORLD'M
CORONADO
for additional information circle no.
9
www.americanradiohistory.com
CALIFORNIA 92118
U.S.A.
h
,
U
21
KENDUN RECORDERS (Burbank, CA) held its first sessions in their new
Studio D using the recently installed Soundstream Digital System. KENT
DUNCAN estimated that the equipment for the new studio would be valued in the
one million dollar range. The console, built by Solid State Logic, Ltd., of Oxford,
England, is 40 -in and 32 -out and incorporates an automation system which provides automated editing of an unlimited number of mixes. In addition, the
computer provides printed track sheets and tape legends from information stored
on a floppy disk. Tape machines include Studer 24 -track machines. The studio
utilizes TM -3 tri -amped monitors, the first ever tri -amping of the Hidley system.
621 Glenwood Place, Burbank, CA 91506. (213) 843 -8096.
RECORD PLANT (Los Angeles) has recorded its first major rock artist on its newly installed 3M Digital Mastering
System. STEPHEN STILLS wrote a special song for the occasion which was engineered by MICHAEL
BRAUNSTEIN with Stills producing the session himself. The 3M system puts 32- tracks on a one-inch tape with
mixdown to a 2/4 track machine using half-inch tape. The Record Plant was one of four studios selected by 3M to
receive the first systems under a special leasing arrangement. 8456 West Third, Los Angeles, CA. (213) 653 -0240.
WESTLAKE RECORDING STUDIOS (Los Angeles) on January 15 announced
the completion of its new "super- studio," Studio B. The new studio is complete
with a 3M 24 -track master recorder. 3M /Studer /Ampex 2 -track recorders, and a
Harrison 4432 C console. The control room uses the new "Westlake" HR1 monitors. The HR1 is a high power, phase coherent, four -way quad -amped unit.
LITTLE MOUNTAIN SOUND (Vancouver, BC, Canada) has installed a 24 -t ack Studer tape recorder which
becomes the second 24 -track recorder acquired in the last 18 months, announced general manager BOB
to its list of client services.
ó BROOKS. In addition, Little Mountain Sound recently added a three-story townhouse
u. "When a group comes to town for a long session, hotel rooms and food can get pretty dull, not to mention
expensive," said Brooks. "Our condominium makes them feel at home." The full-furnished townhouse has three
bedrooms, two -and -a -half baths, fireplace, full basement and a large patio. 201 West 7th Avenue, Vancouver, BC V5Y
1L9, Canada. (604) 873 -4711.
ë
BARCLAY RECORDING STUDIOS (Paris, France) has increased its capacity to 24 tracks according to GERHARD
LEHNER, chief engineer. In November, 40 per cent of the studio was acquired by Philips and another 40 per cent by
the French National Bank Company, while EDDIE BARCLAY retained a 20 per cent interest. Studios Barclay 9,
Avenue Hoche 75008, Paris, France. Phone: 924.81.30/267.05.61. Telex: Barclay 62693F.
to be represented in the next available issue write:
P. O.
R -e /p STUDIO UPDATE
Box 2449 Hollywood, CA 90028
The Symetrix
represents a major
step forward in versatility
CL-100
and cost -effectiveness.
Consider these features: D- essing, Independent attack
and release controls, Side chain insertion which allows an equalizer
to be patched into the control loop for frequency dependent threshold, and
LED gain reduction and threshold indication. CL-100: $299, CL-100B (Balanced): $34
Symetrix, 109 Bell Street, Seattle, Washington 98121 (206) 682 -3076.
R-e/p 22
for additional information circle no. 10
www.americanradiohistory.com
WHY SETTLE
FOR THEM BEST,
WHEN OUR SECOND BEST
IS BETTER.
You see, the Series 'l)
Professional Audio Recorders may not be 3M's
new digital sound, but
you'll he hard- pressed to
find more dclxndable
analog sound.
Start with an unusual
way to have lower wow
and flutter and keep head
contact. It's our patented
3M Isol op differential
capstan -drive. Vt hich cuts
unsupported tape length
down to 31/2" 'l'hen design it all into
a no -warp metal deck
hase plate.
fin:dly, choose from
expandalkejt
16
and 24 channel models.
For more information,
phone R. J. Brown at
(612) 7334262 or write
Mincom Division, 3M
Company, St. Paul, MN
ü101.
lot .uldrt,onal Information circle no
11
10 years
later-
George
Martin
revisited
TOM LUBIN
photos by
Henry Diltz
Tom Lubin: What do you think the role of a
producer is?
George Martin: Big question isn't it. It's
changed. It changes with the time. I guess
the role of a producer is to produce a record
as well as he possibly can, using the best of
the talent available to him, which means that
he has to get more out of the artist than the
artist is capable of getting by himself.
There's been a tendency in recent years for
the artists to want to produce his own
record because the role of the producer has
become too important, it's been kind of self defeating. The 'cachet,' "produced by" has
become such a coveted title that the artist
themselves have become jealous of it. So
they say, well, I'd much rather not have you
around, I think I can produce it by myself. I'd
R-e/p 24
like to have "produced by" not just "sung
by."
In the main I think it's to their
disadvantage, because the problem with a
certain produced piece of work is that the
artist can't be completely objective and a
prime role of a producer is to be objective.
He needs to step back and look at the whole
of the painting instead of just concentrating
on the brush work in the corner. It's one of
the most important parts of making a
record. He must also contribute, and be
creative. He must see within the raw
material, both the song and the voice,
something which can be brought out that
other people may not see. He has various
ways of doing that. Some people do it by
taking their ideas and giving them to the
www.americanradiohistory.com
artist to carry them out. Then the better
ones do it in such a way that the artist feels
he could have easily done it himself.
Tom Lubin: How do you get an artist to
think he had a particular idea?
George Martin: It's not very difficult since
most of them think they did anyway. I'll give
you an example. If I want a particular ending
to a piece of music and the guy, the
composer, goes to the piano and I say,
"That's fine, but I don't like the ending very
much. I think you might do something about
that." And he'll say, "What kind of thing do
you mean?" And I'll say, "Well, I think you
ought to go to a kind of unrelated mood,
finish up some pattern you're doing." He'll
say, "Like this?" "No." He'll try something
YAMAHA'S NEWEST TOURING PROFESSIONAL.
Yamaha's new
PM -2000 Mixer.
Ideal for professional
sound reinforcement,
it's the kind of full
production console
pros have always
had in mind, but.
never in hand.
The PM -2000.
The touch is solid,
smooth, consistent. It
feels like the professional console
that it
is.
The knob, switch
and slider placement anticipate
where your hands
will naturally fall.
With 5- position,
4 -band equalization
and six independent
sends on all 32 inputs,
plus a full function,
14x8 matrix, the
PM -2000 has everything you would
expect from the
consummate professional console.
And if the
PM -2000 looks and
feels like a custom
console, and seems
to have read your
mind, it is no accident. Because
Yamaha spent two
years on intensive
research
and prototypes
based on input from
professionals. One
touch and you'll
realize: the
PM -2000 feels how
you think.
Available soon
on a limited basis,
through select
Yamaha dealerships.
YAMAHA
PO Box
6600 Buena
PM -2000.
www.americanradiohistory.com
Park, CA 90622
Write for complete
information on the
else and I'll say, "No." Well, pretty soon he'll
get it.
I knew all along what it was I wanted, but
instead of taking his hands off the piano and
doing it myself I had him try it, and about the
third time around he had it. Because later
he'll say, "You know George said something
about the ending so I made this change at
the end and it really works great." That's
really how it works. It's a very subtle thing.
Tom Lubin: What we're talking about is
diplomacy.
George Martin: Absolutely, it's essential.
Though it can rebound on you. If you take it
to its logical conclusion sometimes the artist
will say, "So what the hell do I need him for, I
did it all myself anyway." That is the danger.
On the other hand most people do have
pretty big egos, and it is necessary to pander
to it in order to get the best out of them.
Tom: Diplomacy is as much a part of
producing as making musical decisions.
GM: There's an awful temptation if you're
good at something to show off because
Dr. Les Remsen has faith
in Quantum Mixers!
0M -128
WHO
IS LES
-
REMSEN
12 In, 8 Out
...
AND WHO CARES?
while back, Les Remsen bought a Quantum QM -168 mixing board
and set up a small studio in his church. Since that time, he's made over
100 classical music albums for about half a dozen labels, plus assorted
demos and audition tapes. Incidentally, Les holds a Dr. of Music in
performance, was formerly first trumpet in the L.A. Philharmonic, and
heads Avant Records.
A
LES CARES
He may not be recording the Bee Gees or Peter Frampton (they have
their own Quantum boards), but Les Remsen wants every track he lays
down to be the best. That's why he chose Quantum.
WE CARE
Because every artist wants his demo and master recordings to meet
the highest professional standards, we build small Quantum boards with
the same care that goes into our large studio consoles. We also sell our
mixers at a price young artists and engineers can afford. Dr. Les Remsen
puts his faith in Quantum, and so do a lot of others on their way up. How
about you?
111Unn
um
AUDIO LABS,
1909 RIVERSIDE DR., GLENDALE,
R-o/p 26
everyone wants to have people say how
clever you are. Everyone wants to be able to
do something that people say is great. That's
a thing that a producer must always resist.
He really is subservient to the artist. He is
not the talent that is being promoted, he
really isn't. If that were the case he could
then make his own records and be done with
it. He is there to serve, to guide, and
encourage the artists. And at all times he's
got to be careful to not push too hard. He's
got to lead rather than drive.
INC.
CALIFORNIA 91201
(213) 841 -0970
for additional information circle no. 14
www.americanradiohistory.com
Tom: At what point do you think a producer
should become involved with a project.
GM: From the very beginning when the
material is first played. Before the Beatles,
the role of the producer, who wasn't called a
producer in those days, was very much a
role of song picker. The day of the
singer /songwriter hadn't really arrived. The
tendency in those days, pre -1960, was to find
really good professional singers who didn't
necessarily write their own songs, though
sometimes they tried. But generally there
were songwriters who wrote really good
material. But they couldn't perform. It was
the wedding of those two.
The producer's main role in those days
was to pick really great songs for really great
artists and put them together; choose an
arranger or whatever, and produce the
record in that fashion. That's what we all did.
And then came along the Beatles. And
things started changing because the Beatles
started writing their own material. Other
people wanted to do the same thing. A lot of
singer /songwriters came along. And the
producer's role changed. Since the songs
were already there, it became more a
question of shaping the songs; of helping the
songs along. Saying, "Right, I think you
ought to go into the middle eight a bit
earlier," or whatever.
That role lasted for quite a while. Now, I
think we're coming back into the other
phase, because there is no doubt that
albums are selling because of singles. You've
got to have a hit single if you're going to be a
success, and the selection of the raw
material is absolutely crucial. And so we
have the situation where the producer has a
very, very important role of picking songs.
Tom: His role seems to haue been
broadened as well by the extensive use of
orchestration.
GM: Yes, but there's a lot of records
without heavy orchestration; the group does
the sweetening themselves. Use of synthesizers have made it that much easier.
Tom: What do you think the role of the
engineer is?
GM: To make a good technical record is the
simple answer. Again, over the past fifteen
years there have been changing elements
within the roles of these two people.
MorE Than Great Specs,
Great Ideas.
For the past three years we've been telling you about the
benefits of using graphic equalizers; now we've made it
even easier to appreciate them. Introducing the MXR Dual
Fifteen and Thirty -One Band Equalizers. Two equalizers
designed with the imagination and understanding to solve
your toughest equalization problems. Designed for use in
either studios or sound reinforcement situations, our new
eqs offer features not previously available at any price.
The Dual Fifteen Band Eq features two channels of equalization with the bands set two-thirds of an octave apart By
breaking the frequencies down further than conventional
octave equalizers, you now have the flexibility to
contour your music with much greater selectivity. As
most musical information occurs in the midrange.
this is where you need even more definition, and the
Dual Fifteen Band Eq gives you six bands of contour
in this area rather than the usual four. In addition,
each channel has its own level control.
.
The Thirty -One Band Ea divides the frequency spectrum even further. A single channel unit, the Thirty One Band features frequency bands set one -third of
an octave apart, generally regarded to be the optimum amount of resolution.
When used in conjunction with any PA system, our
equalizers can make a bad environment sound good,
and a good performance sound great. Unlike parametric equalizers, the frequency response change is
immediate and easily visible, so that when you shape a
response curve you kr,Jw what it's going to sound like.
Both units feature a range of -12 to +12 decibels on
each band, standard 19" rack mount, and the rugged
construction you always get with an MXR product. Both
units also feature phone plug input/output connections,
(the Thrity -One Band also features Cannon type XLRs),
high slew rate (7V/microsecond), and incredibly low noise
(better than -90 dBM). But not only do we offer great
specifications, we produce great ideas ... you wouldn't
expect any less from us.
MXR Innovations, 247 N. Goodman Street, Rochester,
New York 14607, (716) 442 -5320.
(MXR) Professional
Products Group
CHANNEL ONE
CHANNEL TWO
for additional information circle no. 15
www.americanradiohistory.com
LEVEL
R
7
Many times they've become immersed in
each other's way. In fact, the role of the
engineer/producer has become very
important. I should think of all the records
produced in this country, half of them are
produced by engineer /producers; a great
many are. Obviously, I'm an old- fashioned
type of producer, and obviously I think it's
better to have two heads rather than one, if
they work in good harmony. The complementary roles of a top engineer working with
a top producer produces a better result.
like
When I'm working with someone
Geoff Emerick, who I've worked with for
years since I tossed him in the deep end and
now one of the great producers of all time
we know each other so well we don't have to
talk. He knows what I'm thinking; I know
what he's thinking. I know the kind of
sounds he can get. He knows the kind of
sounds I want. Consequently, we don't get
-
-
Rehearsing vocals for "America ",
Hollywood Bowl.
in each other's way; we don't waste time. He
concentrates like mad to get a really great
technical sound. If I say, "Geoff that bass
drum sounds a bit flabby," he'll say, "Okay,
I've got it." He goes off. I literally forget that
problem, because I know that he'll give me a
great bass drum sound. In the meantime, I'm
working on the music. He might say to me
equally, "Do you think that chord works
there, George?" And I might say, "Yes,
Geoff, I think it does," and I fume a bit. Or, I
might say, "You know, maybe Geoff is right
about that; I hadn't thought about that."
And that's as far as our roles overlap. We
stick to each others' work. And the result is
we come up with something that an
engineer/producer would take longer to do,
if he does it as well, because he's having to
think of all things at once. He has to think of
keeping the band happy, of looking after the
technical side of it, running around to all the
instruments, and so on. And at the same
time thinking of the music. And I frankly
think it's too much for one person to do.
Tom: Do you think your production style
has changed with the advancement of the
recording technology?
GM: Its bound to have changed because of
the years I've been in the business and the
way it started. In the beginning it came out of
a tiny little hole, and that was all the sound
you got. That was a mono sound. It was
really restricted. The equipment you had to
play with was extremely limited. If you
wanted to be avant -garde in any way you
had to make your own tools. It was literally
like living in the Stone Age.
If I wanted an electronic sound there was
just no such thing as a synthesizer. I'd have
to make it myself, bang on the piano wires,
and speed the tape down or double it up, or
whatever. The most elementary way of
doing concrete music. As the techniques
changed, the development of records made
that little hole in the middle a big, panoramic
wall of sound. I see that wall not as a line, but
if I can be a bit pretentious, I see it as a
painting; if I could think in terms of sight in
relation to sound. I'm thinking of putting bits
here and there, and hearing things coming
out, and going back so that there is depth as
well as breadth. I think three dimensionally,
where something is way back behind. A
hundred yards back. And I can hear things
right in front. As I started developing that
process, that was when mixing became fun.
"Pepper" became an ego trip, and a hobby as
well. I used movement. I found when
panning it not only went left -to- right, but it
seemed to go above me.
Later on, when we had quad, we had the
facility to bring the sound out in front of the
speakers. Ah, well! But that died a death.
Tom: Do you think quad will ever make a
comeback?
GM: It may do it, but the improvement of
stereo over mono was enormous; let us say
it was 100 per cent better. The improvement
of quad over stereo wasn't as much, maybe
20 per cent better. And the encumbrance of
it all didn't make it worthwhile for the
average listener in the home. Mrs. Jones will
put up with two speakers, but when it comes
to four she's going to put her foot down.
Tom: The texture of the echo on the original
Sgt. Pepper is quite different than the film.
GM: I think the answer
is that plate echoes
have become better. In the old days at
Abbey Road we used to have a great
chamber, and we would use a combination
R-e/p 28
www.americanradiohistory.com
of chamber and tape. We called it Steed. We
would vary the amount of tape going into the
chamber, and so on; sometimes using it
straight. In the end we'd get a combination of
all things.
Nowadays the EMT plates have become
so good that they almost sound like a live
room. Today we use EMT and tape
together. In fact, we don't have live
chambers at Air. We built one but it didn't
sound as good as the one at Abbey Road and
it took up too much space. EMT's work
better anyway.
Tom: I'd like to go back before the Beatles.
GM: I was running a label. I was running
Parlophone Records. It was a pretty small
label, but I was responsible for all the music
on it and, as I was responsible for the
success of that label, I had to decide what
records to sell. During the time that I was
doing that, the British market was
dominated by the American charts. The
best sellers were all American. A label that
didn't have any American product was
bound to be unsuccessful, and my big
brothers at EMI
which were Columbia
had people like Elvis Presley,
and HMV
Guy Mitchell, Doris Day, Frankie Laine and
Frank Sinatra. Coming in on that Parlophone was never a very successful label. We
had no American artists at all; we had to
make our own.
The British rock and roll industry didn't
exist, then. Rock was just beginning in the
late fifties in England. What we did have was
skiffle. Have you heard of Lonnie Donegan?
- -
Tom: No.
GM: No! He had quite a bit of success. Ha! I
guess it's too far back. Lonnie Donegan was
about 1958.
We had a pseudo rock and roll star, who
didn't really become a rock and roll star at
all, but became a general entertainer named
Tommy Steele. That was after the start of
Presley. Lonnie Donegan started skiffle,
which was kind of a mixture of bluegrass
music, but an English version. And I had a
skiffle group called the Viper Skittle Group
that did very well, and a rock and roll star
named Jim Dale that was not as successful
as Tommy Steele. He eventually gave it up
because he wanted to be a comedian. He
now appears in Walt Disney movies and
such. We had a bit of success with him.
And then along came Columbia with a
new guy that was different than anybody
else but fairly anonymous in his sound, and,
of course, he's still there after twenty -one
that's Cliff Richard.
years
During this time I got into comedy
records. I did an awful lot of it and became
sort of the comedy king in England. I
recorded people like Peter Sellers and Spike
Milligan; shows like "A Drop of the Hat" and
"Beyond the Fringe." There was a whole
string of comedy records. It was a
-
SmoltPtocp Ranch
"AIC and MCI lived up to
their reputations."
"IT WORKS"
,L0,6D
President
SMOKETREE Studio's Automated MCI 528
console and JH 24 Multitrack.
Systems design and installation
by Audio Industries Corporation.
The people
and the products
We have them both.
Smoketree Ranch
9752 Baden Avenue
Chatsworth,
CA 91311
(213) 998 -2097
audio industries corporation
1419 N. LA BREA AVE.
HOLLYWOOD, CALIFORNIA 90028
additional information circle no. 16
(213) 851 -4111
TELEX 67 -7363
R
4
29
Working out vocals.
Caribou Studio.
breakthrough in England because nobody
else was doing it at that time.
During the same time that Stan Freeberg
was a big success over here, Parlophone
became sort of an oddball success for a
small label, and I got the reputation for doing
weird things, but which happened to come
off. I was producing every record on the
label; kind of one man band. I was handling
the business as well, you had to in those
days.
I was very envious of the ease with which
Columbia had hit records with Cliff Richards
because this guy was a kind of sex symbol.
All he had to do was find a fairly reasonable
song and it became number one. Whereas,
there I was sweating my guts out trying to
find a really clever funny song for Bernard
Cribbins to follow up "Hole in the Ground,"
as each one was a one -off job.
I was looking and looking for something
like that. And it was at that stage in my life
when I heard a tape that Brian Epstein
brought in.
I met them [The Beatles] in April of 1962
and signed them in June or July to
Parlophone. We issued our first record in
November, 1962, which wasn't enormously
successful. The first record that became
number one was really the second release,
which was "Please, Please Me," which was
issued in February of 1963.
So began the whole she -bang that became
just one golden treadmill. It never stopped. I
nearly had a nervous breakdown in the
balance. I was producing an awful lot at that
time. Too much.
Tom: In 1965 there was a definite American
sound and a British one. It's become very
much one in the same. You've seen quite a
change in studios.
GM: We always throught we were way
behind and, of course, we were.
Around 1955 when British recording was
fairly primitive, I paid a visit to America.
Capitol by this time had been bought by
EMI. I visited the Capitol tower where Frank
Sinatra reigned supreme. I went to one of his
sessions and was enormously impressed
with the studios. They had things like
limiters, which we didn't have. They did
things to sound which we couldn't get. And
they had three -track recording on half -inch.
We were still in stereo. We had twin-track.
That's all we had. It wasn't just the facility or
tape; the whole approach was much more as
it is today. It was the beginning of the
electronic revolution. Their monitoring was
better. The handling of the whole thing was
very impressive, very modern.
So I went back to England saying, "For
Christ's sake, we've got to pull our socks
on!" I started beating around the EMI people
telling them they had to have better
machinery and better studios otherwise we
couldn't compete.
It so happened that during that same time
a new generation of recording engineers
were developing at EMI. I will say this much
for EMI: It was a breeding ground for talent
and, though they didn't provide us with very
many good tools, they didn't stop us from
experimenting. It was almost like a
laboratory. It was generally done on a
shoestring. We'd listen to other people's
records and try to figure out how they were
done and try to do them ourselves, though
not very successfully.
We had very limited technology, but
the beginnings of
eventually we got it
multi -track. EMI made their own tape
machines, and then we started getting
machines from Germany and limiters from
America, and new kinds of microphones
from the Continent. And the whole thing
started moving along.
By the time The Beatles had made their
success we were getting pretty good
sounds. The studios had a tradition of good
acoustics and once they were coupled with
the modern technology they were as good as
any studios in the world.
When I went back to America in the heart
of The Beatles thing, I went back to the same
studios that I had seen years before at
Capitol and I found that they hadn't changed
and were now very old- fashioned. I was
shaken. We had reversed places.
-
Tom: That was cbout 1965. At that time the
acoustics of English studios seemed to be
quite different in design than their American
counterpart.
GM: Well, it's very difficult to generalize
because studios vary like hell wherever you
go. It's still true to say that most American
studios are deader than most English
studios or Continental studios. Here they
seem to like wrapping the drums up in a
soundproof box so the sound doesn't go out
too much. The Ridley designs always
provided a drum box in the corner with a
bass trap overhead to soak up sound. The
obvious thing of having that kind of
treatment is you get very good separation
which we tended not to get in our English
studios because of the very nature of our
livier rooms. But we used to get a better
string sound and generally more "air"
around our recordings. I think that's still
like the rest of the
true, but as you say
world we've tended to become less different.
...
R-e/p 30
www.americanradiohistory.com
mean it's in everything; in our way of dress,
our lifestyles. The world is shrinking.
There are one or two studios in Los
Angeles that are like British studios. There is
still a difference between a British and an
American studio, and it's obvious I prefer
the British ones.
I
Tom: Do you think there's a difference in
engineering attitude between the British
studios and the American ones?
GM: I think the engineers in England are
trained more to pay attention to detail. I
don't mean to sound like carping, after all
American studios are very good; but we
tend to line up things with a greater degree of
accuracy and consciousness.
For example: Dolbys. We tended to use
Dolbys before America. In the early days
Dolby got a bad reputation in the States
because people said they colored the sound.
I think they do, actually, but that's neither
here nor there. There was a very strong
feeling against them but we preferred the
coloration of the Dolbys to the hiss. Now,
granted, we spent a long time before each
recording making sure that every one of
those Dolby units were really right, really
tuned properly. I found that when I came
over here I was getting bad results from
them so I started using 30 ips without
Dolbys.
In England where I could control them and
I knew what I had, I used them. Now,
curiously enough, Americans are tending to
use Dolbys more whereas we are thinking of
dropping it all together. I have Dolbys in
Montserrat only because I have to. When
I'm working there I won't use them.
Tom: Why do you think there is such a
difference between English and American
engineers?
GM: I think there are different pressures on
English engineers. I think they're not as well
paid, which is cutting across my own
argument while on the other hand I don't
think they have the internal pressure that
American engineers face. Here in the States
we seem to grind the engineers into the dust
and expect them to be there the following
morning at 8:00 a.m. when they've just
finished a session at 4:00 a.m. They're
expected to work around the clock, and
weekends are an automatic rule.
You question one of them here, "What do
you mean you didn't have a holiday this
year?" and he'll answer, "I haven't had a
whole day for the past five years." I think we
treat engineers a bit more humanly in the
U.K. even if we do pay them worse.
Tom: Who are you influenced by? So many
people listen to George Martin records.
GM: I don't listen to much more. Obviously,
I listen to the records that are high in the hit
parade or anything that's been brought my
way as being interesting, but I don't really
The new DN34
analogue time processor.
IMP
L.
Ja.0
KANN-MENNIN
ON -3E
,.
ANALOGUE
ty:
E"
L..R'u
IRK
PROCESSOR
r.-.j
Think of the effect you'll have.
The new DN34 analogue time processor
is an exceptionally versatile signal processing
and special effects unit, designed around two
discrete, independently controllable delay
sections.
Like other Klark-Teknik products, the
DN34 is the result of intensive research and
development -the best there is in state- of-.theart analogue delay technology.
With a product of this stature you can
achieve all these effects cleanly and noiselessly.
Positive flanging.
Pitch detune.
Negative flanging.
Pitch shifting.
Double tracking.
True vibrato.
Resonant flanging.
Chorus.
'Cardboard tube' echo.
Triple tracking.
Loudness
enhancement.
The DN34 analogue time processor also
offers you:A dynamic range better than 90dB.
A time sweep range of 70:1.
T.H.D. at less than 0.3 %.
Numerous exclusive features including full on
board' mixing and phase reversal facilities.
Amazing performance and value for money.
The DN34 is unequalled in the signal
processing field today.
And we're not just saying that for effect.
Doppler/ Leslie effects.
KLARK= rEK11111
And, if this isn't enough, the DN34 can give
you such new effects as:Crossover flanging.
Time -related
frequency synthesis.
Complex Doppler
effects.
for
1(1.,1unel
You know
its the best.
For further Infcrma-wn about the DN34, our new DN70 digital time
processor. and also our DN27 and DN22 graphic equalisers:
Hammond Industries Inc. 155 Michael Drive,
Syosset. New York 11791(516)364-1900; West Coast
Office (213) 846 -0500: Canada (416) 677 -0545
nformat,on circle no.
17
www.americanradiohistory.com
{7
p31
listen to a great many records. I don't really
get all that much time to just listen. I do most
of my listening in the car.
Tom: I'd like to talk about the Jeff Beck
"Blow by Blow" album. That album stands
alone as being quite different from all the
other records that you've produced.
GM: A lot of people told me I shouldn't do it
before I did it. The combination of Jeff Beck
and myself was an unlikely one; for that
reason I wanted to do it. I've always admired
his guitar playing which is fantastic. We got
on fine; we were both prepared to do
something different.
Tom: The guitar sound on "Blow by Blow"
has a great deal of space around it.
GM: We used a big room to record. With
Jeff I set out to get what he wanted to do and
what his sound was. Jeff is not a very
technical person. He's the kind of guitar
player that plays by the seat of his pants.
When we were doing "Blow by Blow" he had
pretty rotten equipment. I think he had two
guitars and, at any given time, only one of
them would be working. He'd be cursing the
thing and flinging it across the room saying it
was no good and he wanted another one.
When he played he would generally bring
a small amp and we'd use number one at Air
as a kind of ambient chamber. The guy who
engineered "Blow by Blow" was Denny
Bridges. He doesn't do too much engineering these days but is helping John Burgess
with Air Studios. Dave Harries, the manager
at Air, is out at Montserrat developing that.
Denny did get a good guitar sound because
it was a fairly natural one. We didn't use very
much direct insertion, we did it mostly
through an amp, using the studio.
Tom: Did you have Jeff working in the
studio or was he working in the control
room with lines run out to his amp?
GM: When we were working with the group
we had him in the studio. When he was
overdubbing we had a line running to the
studio and he was playing in the control
room.
-
with
Tom: Do you like working that way
the player in the control room?
GM: Sometimes, but sometimes it doesn't
work. I've seen an artist get awfully inhibited
with everyone sitting around waiting for him
to produce a work of genius. Jeff found that
very inhibiting. Jeff is essentially a guy who
does his best work when he's blowing to a
crowd. Within the confines of the studio he
found it very difficult to play anything
inspired. The only difficulty I had with Jeff
was that he would play something I would try
to encourage him by saying, "Yes, that's
great
now try it again." And he'd turn
around and say, "You know damn well that's
...
not great, it's absolute crap." That was the
kind of problem one would get.
Tom: Were Jeff's guitar parts pretty much
complete takes or was there a lot of
punching -in or multiple takes?
GM: Generally we had a number of takes.
-
often, and I'm always somewhat embarrassed about it because the truthful answer is
that to most of these specific questions I
have to think very hard because I can't
remember. When I've done records in the
past I just do what I think is right for the time.
I certainly don't make notes about it. I think
we did the brass on "Hideaway" back in Los
Angeles, at Western. I like Western. We did
some in that big room in Burbank. I think
that was the orchestral things. I don't think
the brass were done there. To my memory
we didn't use anything special on the horns.
It was Geoff again, and he was just using the
microphones he aways uses. I use a large
section, or at least on those recordings I did.
I wrote it like it would be a performance.
The Series 1600
Recording Console.
VCA grouping, Automation, Spectrum Analyzer.
Available with
Trans -Amp LZ *.
Sound Workshop
'Registered trademark of
the Valley People. Inc..
Nashville. Tennessee.
PROFESSIONAL AUDIO PROD.JCrS
Sound Workshop Professional Audio Products, Inc.
1324 Motor Parkway, Hauppauge. New York 11787 (516) 582-6210
R-e 'p 32
for additional information circle no.
www.americanradiohistory.com
Write to us for details.
18
-
Tom: On one of the America records
particularly "Hideaway" the brass sound
is excellent. Do you happen to recall how
you recorded them? Do you use a small
brass section and then double- and triple track them or use a large one, much like an
orchestra?
GM: I'm smiling because I get this quite
Tom: Do you approach it like it was a
classical recording using, say, a stereo pair
of microphones.
GM: Yes, we do use that on strings quite a
bit. It's a combination of that and direct
miking as well. I mean if you can get away
with just a stereo pair on an orchestra and
your using a good room, it's a lovely sound.
But it's very difficult to do that when you
need things brought out; they need a certain
amount of help. I try to write most of my
score so they sound naturally right without
having to artificially raise the volume of any
particular one section.
Tom: Do you write your score before the
basics are cut?
GM: No, generally the score is the last thing
to be done.
that. So I decided that what I would do would
be to make the music sound fairly authentic
where in the picture the group is supposed
to be an up -and- coming group. Then make
the music a little more sophisticated as they
became more successful. We started off
with the original sound and then brought it
up to date.
You might say what The Beatles would
have tended to do if they were still working
today. I wanted something where the basic
rhythm tracks could be a little bit more hip
than the basic rhythm tracks of 1964..
which weren't very clever, you know; just
sort of a bashing noise, really. They were
.
good records, but there was nothing
particularly hip about them. So I wanted
something a little jazz oriented. It was
slightly watered down because of the songs
themselves. There's only so much you can
do without destroying a song.
Tom: ¡ wondered if you used any processing
on the Alice Cooper vocal.
GM: That was just him. I got him to speak it
or hiss it more -or -less. You see, it was a
nasty bit of work in the film. The sort of
cloying vocal effect on the original was
duplicated by the Bee Gees, which was
countered by the nastyness of Alice Cooper.
The SGT. PEPPER MOVIE
Tom: For the Pepper movie was it
completely scored before being recorded?
GM: It really depends on what part of it
we're talking about. There was an enormous
amount of work involved. There's about 200
minutes of music. I was scoring right up to
the film dubbing. Little background bits here
and there. Sweetening, for example, on the
Alice Cooper tune, "Because," was basically
very similar to the original except for his
spitting out the words. But, in fact, it wasn't
because there was a lot of sweetening on it
that was not on the original; strings and
such. They were rather weird strings that
were done to fit the picture.
Have you seen the picture?
Tom: I tried seeing it, but it wasn't playing in
San Francisco.
GM: I don't suppose you've missed very
much. It wasn't the best picture in the world,
but neither was "Grease." So on one hand
you have an enormous success and on the
other a bomb. I can only presume that
people weren't prepared to accept a third
Stigwood film. I think the public had a
reaction to it. The fact that The Beatles were
being played by the Bee Gees and Peter
Frampton must have incurred some sales
resistance before the word go.
Tom: I would assume that you were given
which song would be done and who would
sing them.
GM: Yes.
Tom: Were you able to pick your players?
GM: Yes.
Tom: You must haue put quite a lot of
thought into who would re -play those basic
tracks.
GM: Well, I was in an impossible situation
anyway having to make a soundtrack of
Professional performers for stage and studio...from ATLAS SOUND,
the world's leading manufacturer of
microphone stands and booms.
Take these Porta -Stand headliners for example. For today's artist there's Model PS-C,
America's first floor stand with spring- action
telescoping legs, most practical where mobility or transportation costs are a consideration.
For acts that have their ups and downs.
Model PS -S features our exclusive touch control clutch that makes height adjustment
so easy, you can raise and lower the microphone with one hand tied behind your back.
There is Model PB -1, one of a ser r ...
new easy- adjustment microphon
boom attachments which fit all
ATLAS SOUND microphone
floor stands.
And, for choir or studio, the mobile model
SB -100W Boom, 9 ft. long, with its unique flex-
ible drive balance -control and 350° microphone- follower.
There are even two new desk -top microphone stands
one of decorative Carrara
marble, the other with a vibration- isolating
base for sound- absorption no matter how
strong the beat.
For details on these and other microphone
stands; accessories headliners, Contact:
ATLAS SOUND, Division of American
Trading and Production Corporation,
10 Pomeroy Road. Parsippany,
NJ 07054; Tel. (201) 887 -7800.
-
>e
for additional inlunnat,on circle no. 19
www.americanradiohistory.com
R-e/p 33
George Martin with engineer Geoff Emerick.
-
the last
Tom: On "A Day in the Life"
piano chord. I was wondering if you had
gone back to EMI to get the same piano.
GM: No. To begin with, on the original we
used three pianos: two grands and an
upright played three times. In other words, I
played one and John and Paul played the
others. We all played the chords. As a
matter of fact we had several people on a
piano. We'd count and hit the chord
together, and then overdub a couple of
times with lots and lots of percussion.
This time we were working in Cherokee
Studios and I just used one piano. What I did
there was to do it about nine or ten times on
24- track; each time I did it in a different key
to give me different overtones. So if the basic
chord was in F, I put one chord down in F.
And then I would speed up or slow down the
tape and play the chord in a different key to
change the timbre. I used ten completely
different keys at different speeds. When it
was put back to normal speed it was
monstrous. I did something similar with the
strings.
In fact, I had to explain what I wanted
done. I divided the cellos and gave half of
them just the root note. They were to play
very softly to give me a sense of tonality to
the whole chord. To the violin, viola and the
rest of the cellos I told, "These are the notes
you play. Let's say it's an E minor seventh
chord, so you play E, G, E and D, and you
an A. What I
if you want
can also play
want you to do is play any of those notes
ultra- pianissimo at any time in the sequence
you feel like; but they must be in this tempo."
The tempo was a very quick rhythm pattern.
Every person was to do something different
than the player who was next door to him.
They all looked at me as though I was crazy
and deaf. So! ... what we got was this kind of
shimmer of any minor seventh chord. And it
sounded good. It was just an effect. I did that
seven times over with seven different chords
and kept it going for about twenty seconds.
Then we made loops of each one, put
them on machines and played them through
faders and dubbed them over to seven
tracks of one 24- track. I had a continual
sound of whatever the chord was, and then I
just mixed in where I wanted it. As the song
went through I would play the fader like an
-
-
organ, fading up the strings as a background
for the song. It doesn't sound like strings,
but it doesn't sound like a synthesizer either.
Tom: Do you use a conductor so that you
can be in the control room and hear the
results, or do you stay in the studio and
listen to just playbacks?
GM: Sometimes I just get the first violin to
take it.
Tom:
On
the new
version
SB8
switchboard monitor
External program feed with volume control
Wide frequency response (200Hz to 12kHz) for exceptional
intelligibility
Designed for high noise environments
Visual signalling uses bright amber lights
Adjustable sidetone reduces feedback and background
noise
Tom: There was quite a lot of phasing on
"Lucy in the Sky."
GM: Yes, that was a weird one, too. A lot of
synthesizer stuff on that. Michael Schultz
wanted a very psychodelic effect. He wanted
it to be a dream -like sequence, so we did
rather over -do it.
Tom: You worked off the script?
GM: Yes. I worked very closely with the
director.
Tom: Is that why you did it here in
Hollywood?
Clear-Com
intercom systems
for additional information circle no. 20
.
the whole set, though undoubtedly some
leakage of the rest of the kit got phased as
well.
Mic on -off feature standard with headset and remote stations
Single and two channel systems virtually immune to RF and
SCR dimmer noise
Remote stations available in portable wall mount and rack
mount versions including speakersfor paging and monitoring
Catalogue with complete specifications available upon
request
www.americanradiohistory.com
.
GM: Yes, we phased just the overheads, not
THE STATE OF OUR ART
New "series If" improved headsets
50 station capability with up to 8 channels using
of "Good
Morning," the phasing effect on the drums
759 Homson Street
Son Francisco. CA 94107
(415) 989.1130
GM: They insisted that I do it here because
were so late with their cutting.
Ordinarily when you do a film you get
measurements from the director. You get a
they
rough cutting and then when the picture is
finished, or almost finished, you'll get a fine
cutting or editing. You can't really start
scoring while the director is still chopping
the film around and altering the length of
things so you don't really know what you've
got to write to until you have the fine cut.
Well, I was promised the fine cut on April
the twelfth and was geared up to leisurely do
the scoring after that. As it turned out, we
didn't get the fine cut until two weeks into
dubbing. He'd actually finished some of the
reels and started dubbing while others were
still being cut.
Tom: How much was recorded before the
film was shot?
GM: I did the basics first and all the
sweetening was left until afterwards.
Tom: The vocals were also later?
GM: No, the vocals were done before
shooting. They had to sing without any of
the strings and such. But it wasn't quite as
simple as that because quite often he would
cut a song. For instance, George Burns'
vocal on "Fixing A Hole." Although I had
done all the vocal that song was cut in half
and whole phrases were taken out. Michael
would come back and say, "Look I want to
get rid of this sequence, would you mind him
not singing this line." And I'd say, "Sorry,
you can't alter the song that much." In the
case of "A Day in the Life" he wanted to cut
out the complete middle of it. I put my foot
down and said, "No, you just can't do that."
couldn't do the conducting myself, so they
got Elmer to do it. Well, some of the scores
that I had originally done had got lost, and I
didn't have a copy myself. So Elmer, though
I don't think he did it himself, got someone to
listen to the record and take down the
scores so they could be reproduced with the
live orchestra.
When I heard the scores they sounded
different. They were written in a way I never
could possibly have written them. The notes
and chords and lines were right, but the way
they were disposed over the orchestra was
different than my style of scoring. The guy
had listened to the records and had figured
out that I'd done things that I really hadn't
done, which was interesting. Elmer hadn't
seen the difference either. There was a lot of
dividing of the string lines which I rarely do. I
guess they thought it made things sound
fuller.
Tom: While doing this project you must
haue had a number of moments that took
you back ten years. Deja vous
there
must have been a measure of sentimental
feelings.
GM: I got over my hangups when I decided
to do it because I thought that if I had
hangups about it, I'd never be able to do it.
For a start I didn't look at is as though I was
making a record. I had made the record in
1965; this was making a film, and that was
how I got past it. I really didn't relate to what
had happened before except as a basis from
which to start. It was like being involved with
Gershwin's "Porgy and Bess" on the New
York stage and then having to do a film some
fifteen years later.
That was my justification for sticking fairly
close to the originals. I really didn't view it as
a duplicate of the record.
Tom: That album was cut live at Greek
Theater, in Los Angeles. Did you have any
particular problems working there?
GM: No, it's a good place, one of the best
around. It's a damn sight better than
Hollywood Bowl.
Tom: On the live America album Elmer
Bernstein conducted. How did you like his
conducting of your score?
GM: Real nice. Very good musician. I
Tom: America's "Harbor" record was cut in
Hawaii. You cut all the basic and vocals
there and sweetened it back at Air?
GM: That's right. We did absolutely
...
DYNAMIC VERSATILITY
TO ACCENT
ANY
TYPE OF PROGRAM MATERIAL
IS YOURS WITH
alb
man,
Vai
Vann
lima
hatli
DYNAF
LANG
E RTM
-
FEATURING TRUE AUTOMATION
WITH PROGRAM CONTENT AUTOMATICALLY CONTROLLING
PROGRAM
CONTENT IN ACCORDANCE WITH PARAMETERS THAT YOU ESTABLISH.
MIX MICMIX Audio
Products, Inc.
(214) 352 -3811
for additional information circle no. 21
www.americanradiohistory.com
2995 Ladybird
Dallas, TX 75220
everything that could be done without an
orchestra because it was a pretty expensive
process just recording out there. You know
we had built our own studio in a house. I had
done that before a number of years ago
while I was recording Sea Train in
Massachusetts. But in Hawaii it was the only
thing to do because there wasn't a studio
there. The only studio in Hawaii was on the
island of Oahu, which was a 16- track. The
boys wanted to go to Hawaii, so we found an
old, large house on the seashore that had a
good room in it and we made that our
recording studio.
I did a kind of reconnaissance with Geoff.
We gave the realtor the specifications as to
!
MLU*
what we were looking for, and then had
carpenters build what we needed, batten
screens and things. We hired a Yamaha
piano from Japan, and brought in Record
Plant's mobile truck. Geoff used the same
desk later on the boat with Paul McCartney.
We had our own little studio right there ..
very cozy.
.
The AIR MONTSERRAT STUDIO
Tom: Tell me about the new studios.
GM: The new studios are on Montserrat,
which is a small island 27 miles from Antigua.
FzISTG c to. RiotT
1114,11011.'
csL s.>,
Antigua is in the middle of the chain of
Caribbean Islands. Antigua is kind of a focal
point because it's an international airport.
You can get to New York, Toronto and
London on direct flights. So it's quite
convenient. We've got a thirty-acre site
there. It's a lovely island, very green.
We chose the island because I wanted to
build a total environment studio. I'd been
looking for a long time. In fact, Hawaii was
very appealing. When I did that album with
America on the island of Kawaii, I was sorely
tempted to try to do a studio there, but
decided against it when I found out how
expensive property was on that island. Also,
the cost of living is very expensive, and it's
-
r-LILN
C.&I.T% ROOM
FFo4cspo
J
0
PUMP YoOM
V
10t4
GOLfIROL ROOIR
Nuot
AIR STUDIOS
MONTSERRAT
Mq.
R-e/p 36
www.americanradiohistory.com
one HELL of a way from London. Lastly, it's
American soil, which didn't make very much
sense for a British citizen. So I was looking to
building a studio which would be within easy
reach of London and most of the places in
America. Antigua certainly fits in with the
East Coast. But admittedly it's more difficult
to get to from Los Angeles than it is to get to
Hawaii, but it suits my bill very well.
We were able to build a studio from the
ground up, which we hadn't done before. As
you know, Air studios was built in a
department store banqueting room 65 to 75
feet long and 45 feet wide. We had a lot of
problems inherent in the site due to the fact
that it was on the fourth floor of a
department store, in a steel frame structure,
over three underground railways, and a lot
of traffic noise outside. We had to be very
careful in our design of Air. We used Ken
Shearer for that one. We designed the
studios ourselves but the acoustics were
worked out by him. Once we got in there we
did some changes to tighten it up a bit.
Tom: It has a control room window that
overlooks the street?
GM: That's right.
Tom: I love a studio that has a window that
opens to something besides another room.
GM: So do I. Funny thing when we first built
it we had a certain amount of comment from
the rock groups who on seeing the outside
didn't like the daylight. They found the
outside distracting. But they're coming
around to it. At the new studio there's
windows. I have this picture window giving
me a view of the bay and the mountains
going down to the sea. I shall sit in a
complete daze and not make records at all!
Tom: Who designed the new studio in
Montserrat?
GM: Well, we've done it literally ourselves.
We used an architect, of course. But Dave
Harries, who's the studio manager at the
London Studio, is
a
great technical
influence. He's very good on sound. He
designed our own speaker. I got him very
heavily involved in the design of the new
studios. He knew what I wanted so he
worked out the acoustics for me.
Tom: Describe it.
GM: It's pretty typical. It's rectangular and
looks pretty normal. There's no point in
having butterfly winged studios, or conical
shapes or tetrahedron for the sake of it. It's
better with it rectangular with a corner out of
it for a piano trap. The piano disappears into
its own trap. There's a bass trap and a guitar
trap for the heavy instrument. There's also a
live area for the others, but it's basically a
fairly large studio. I like having a bit of air
around the drums and not locked away in
some box. There's also an overdub room
next to the control room.
Tom: Is the control room window in front of
the console or to one side, as typical in many
English studios?
GM: It's in front. And you have one into the
vocal booth. I guess the control room's
emphasis is on size. I like plenty of space in
my control room as well as the studio. My
main criticism of most of the studios I've
been in is that their control rooms are much
too small. When you have a group coming to
listen to their record, and there is only three
feet of space where it's good to listen to, then
everyone has to huddle around on each
others' shoulders. The control room we
have in Montserrat is 24 by 20 feet. It's
almost the size of the studio.
Tom: How high is the ceiling?
GM: Not too high. It's about ten to twelve
feet high.
Tom: What are the speakers like? You
mentioned that they were custom made.
GM: They're basically Tannoy Gold units
which have their own tweeters built in them.
The enclosure is Dave's design, rather like
the Lockwood cabinets, but a bit better than
that. They're very flat. So we have two kinds
of speakers, our own and the JBL 4311,
which I find to be a very good speaker.
At Last,
a Cart Machine that Keeps its Cool
Telex /Magnecord broadcast cart machines run
cool and steady. So cool no ventilation is required, so steady not even voltage or frequency
fluctuations will alter their speed. Thanks to
our dc servo flutter -filter drive.
The MC series offers broadcasters a host of
options, including field convertability from
mono to stereo or play to record and, of course,
end of message, secondary /tertiary cue tones.
Designed for type A or B carts, the MC series
meets all NAB specifications, offers full immunity to EMI and RFI, is remote controllable
and automation compatible with CMOS digital
logic. Audio muting, air damped low voltage
dc solenoid and fast forward are standard features on every MC unit.
Four broadcast cart machines to choose from
in the Telex /Magnecord MC series. Running
cool and steady. With a pleasant surprise
they're affordable.
For detailed information please write:
-
PRODUCTS OF SOUND RESEARCH
TELEX®
COMMUNICATIONS INC.
,
9600 ALDRICH AVE. SO MINNEAPOLIS. MINN. 55420 U.S.A.
Europe: 22 rue da la Legion- d'honneur. 93200 St. Denis, France
Canada: Telak Electronics. Ltd Scarborough. Ontario
for additional information circle no. 22
www.americanradiohistory.com
.
Fro p 37
GM: A Neve, 52- input, 32- output with
separate monitoring systems. Not an in -line
desk. I like to have my own monitoring
section.
Conducting at rehearsal
...
Tom: What equipment haue you chosen for
Montserrat? Are you going to haue digital
recording?
GM: Well, all my life I think I've been in the
forefront of studios while trying to make Air
the best, always trying to be better than
anybody else. I looked at digital very closely;
I'm very aware of it all. And I've been aware
of the growing complication of analogue
recording, and the growing expense of it. A
point is going to be reached where someone
is going to say, "Halt! This is enough!" I think
I've gotten to that point now. But in making
the studio in Montserrat I wanted to have
best facility not just in the
Caribbean, but in the world. That didn't
mean that I had to go into digital, because if I
went into digital I wouldn't have the best
recordings in the world, might have the
most avant -garde ones, but it certainly
wouldn't cope with the majority of
recordings being done today.
the very
1
Tom: What board do you haue there?
Tom: Automated?
GM: No. We have automation at Air. The
new board could be automated if I ever need
it, but since automation is only really used
for mixing, and since I don't anticipate at this
time that we will do too much mixing. At
Montserrat I didn't get it.
It's much more likely that people working
there will concentrate on basic tracks for
three or four weeks, and then go back to Los
Angeles or New York, or wherever, and do
sweetening and mixing.
the rest of it
It's a new transformerless system of
Rupert Nevé s design and will be the only
one of its kind. lt's got completely new EQ
facilities. It's very expensive and very good.
In fact, the figures on the tests are just
incredible.
-
Tom: What sort of tape machines are you
going to use?
GM: We use Studer in England and I was
sorely tempted to get the new Studer 32track, 3 -inch machine. But, frankly, I don't
like 32 -track or 3 -inch tape; but it's got to be
provided at the facility. Because we're so
near Florida and they're very good
machines, we've ordered the new MCI 32-
track machines. We haven't gotten delivery
on them yet, but we'll be the first to get them.
The new ones will be optional 24/32 with
interchangable head blocks.
I personally will never use 32- track. I think
46 -track using two 24 -track machines in
sync makes much more sense. However, if
you're a tidy producer you shouldn't really
need more than 24. If you do need more than
24, which I did on the Pepper film, there is no
sense going to 3 -inch tape. lt's different
technology; more flapping problems; more
storage problems, and so on. What you
should do is whatever you've got on the first
24 mixed it down to a rough stereo and put it
on a second 24. To do overdubbing, let's say
you'll work five weeks on one particular
tape. The amount of spooling back -andforth, to- and-fro is enormous. The tape wear
is fantastic. Why should you keep wearing
down the original tracks that whole time?
You're not wearing them out at all if you're
working on a second reel. When it comes to
mixing, what you've got to do is sync the two
together and away you go. That seems to me
to be a lot more logical than running a 32track thing back -and-forth a few thousand
times just to get one vocal or some other
equally time- consuming overdub.
Tom Lubin: In 1971 you were interviewed by
Many things which you felt would be
a part of the future of recording haue come
R -e /p.
This singular
lower
idrange
system
improves intelligibility in the
voice frequencies to a new order in high
power sound reinforcement. The
exciting new ATC 9" driver connects to
a straight exponential horn using an
integral phasing plug for enhanced
dispersion. The hand -laminated
fiberglass horn is lead -sheeted and
polyurethane damped to eliminate
resonances, even at 130 dB SPLs at
the throat. Its built for the road and has an unprecedented
six year warranty. Call or write for the 'works".
Eastern Acoustic Works, nc.
59 Fountain Street, Box 111, Framingham, Massachusetts 01701/(617) 620 -1478
R-e/p 38
for additional information circle no. 23
www.americanradiohistory.com
to pass. One of them was the emergence of
video as an integral part of a musical
presentation.
George Martin: Sure, it was bound to
happen. I must confess that if I said that
seven years ago I was being a bit premature.
It hasn't been all that fast. It's a question of
economics rather than the arts. And what
people are prepared to pay for it.
Tom Lubin: Air was the first studio in
London to have the capabilities to do both
recording for records and for video.
George Martin: That's true.
Tom: Where do you see the direction of
technology?
GM: Well, digital is going to be here. When
we were talking about Montserrat, the
reason I said I didn't want to go digital ...
think the degree of sophistication on our
new Neve is about as complicated as I want
to go on a desk and about as big as I want to
go before I go to digital.
Digital is now in its infancy and we've been
guinea pigs for an awful lot of years. We're
letting other people be the guinea pigs this
time. In three or four years we'll take all the
hard lessons learned by other people and
use it where it's properly used.
In any case I think digital recording will
only come into its own when it becomes
completely integrated with the desk. I think
just having a digital machine connected up
to an analog desk doesn't make too much
sense to me. That's just cutting down on
your noise a little bit; but that isn't a major
problem. I think when the tape machine is an
integral part of the console, and it's a
completely computerized unit which can do
things that you can't do now, like
synthetically process an echo sound that
imitates "Heartbreak Hotel" without an
echo unit ... that kind of thing. Then it will
make sense. But that's aways off.
I heard the Soundstream stuff about two
years ago, but I'm afraid I haven't kept up
with the latest developments in digital
technology. I've obviously read about them,
but there isn't all that much development.
I'm a bit surprised that the development
hasn't been quicker.
1
r The Record Pressing Problem ?
Tom: Would you care to comment on the
quality of pressings?
GM: It's a hell of a problem 'cause you never
know about it. We spend hours in the studio
getting a great sound. We take a lot of
trouble, and because we don't want it to go
into the hands of an idiot, we go along and
we have it cut by someone we like and know
well. We know what he does, so we spend
more hours with him in the cutting room to
get the lacquer right and then we approve
them.
Then we hear
a
test pressing and it sounds
good ... fine. But what we don't hear is what
happens to the thirty- second run at the
Scranton plant, or what happens in Turkey.
Or what happens when the tapes are
shipped to Japan. We do hear eventually.
I've heard some ghastly reproductions of
something I've done. Christ! How'd that
ever get out!
And I know for a fact that an awful lot of
records that get out in this country bear no
resemblance to the record we've made.
They're issued that way and people buy
PRESENTS THE
$100
MICROPHONE
STAND
them because they don't know the
difference. I never hear them because I don't
buy records at a store in Pennsylvania to see
if my "Blow by Blow" is good enough, and I'm
sure it isn't. Quality control is a hell of a
problem because we don't know how good
or bad it is. The record manufacturers really
don't know. And I guess when it comes
down to it the economics of the thing are
pretty paramount.
Tom: What can artists, producers,
engineers, or even the consumer do about
it?
GM: They can only make noises to the
record companies. The record companies
can only make sure that their quality control
is stepped up so that they don't issue too
many duff records. But, then, there are
always alibis. The record company can give
the artist a perfect copy, saying that it just
came out of the Scranton plant and there's
no way that they'll ever get any better than
that. Though the company knows perfectly
well that all the records being pressed are full
of carbon dust, or whatever.
-
Tom: Are their reasons legitimate
or are
we expecting too much?
GM: I don't think we're expecting too much,
no. But in relation to today's civilization it's
just like buying a car. You'll get your Friday
one as well as good ones. You buy a car from
Ford and the advertisements look great.
Then you take it on the highway and you find
that the throttle cable is sticking. There's no
way that you can do it except by attention to
detail all the way down the line. Those
people doing those terrible, boring jobs just
have to do it a bit better. It's a big problem,
and I don't think that it can be overcome
very easily.
Tom: What do you say to people who write
you letters. "Mr. Martin: How do I get into
the business?"
GM: Don't. Too many people want to get
into the business, that's one of the problems.
An outside viewer of our business really has
no idea what he's getting into. You don't
have football pools in this country, do you?
You have some kind of gambling?
JP'
Sure, they come cheaper.
But only Boilermaker gives
you all these top quality features: 6061 aluminum alloy,
machined steel base ..
a choice of five show stopping colors to choose
.
from.
If you can tolerate only the
best in your act, act now and
call us for all the details.
B)' NORTHWEST .SOUND
\R )rn
...
concluded on page 100
-
1147
brnur
l'11
:1 í Sr;
P5n1,551 (Arge m 97205
sat
N,
!1i 154
Re/p39
www.americanradiohistory.com
The first
Time Aligned
Control Room
Speaker System
T
MrED
Congratulates
Martin Audio
on their
move to new
and modern
quarters at
423 West 55th Street
6th Floor
(Between 9th & 10th Ave.)
New York, NY 10019
(212) 541-5900
Martin Audio
continues to be
one of our
top dealers
for
UREI Products
which can now
be seen in their
new expanded demo
and display rooms
M.
Unbellei'thy
Clean.. .from
a whisper, to
the threshold
of pain.
The UREI 813 Monitor Loudspeaker System brings impressive
new realism and clarity to recording control room listening.
This first Time AlignedTM professional monitor employs the
efficient Altec 6048 -G duplex 15" driver with a UREI custom
horn for extended and more uniform H.F. response. plus an
added 15" direct radiating driver for extended L.F. response
and higher power handling. Add to this the UREI 3 -way
7 '
1
í
a"j,
1
-
network in a unique pressure controlled
M
enclosure and you have unbelievably clean
reproduction from low levels to the threshold of
TAT
pain! Bring your aspirin and hear it at your UREI
dealer.
LOOK TO UREI
FOR ALL YOUR
AUDIO SIGNAL
PROCESSING AND
SPECIAL
INSTRUMENTATION
NEEDS
ComActive Equalizers and Filters
pressors
Limiters.
Crossover NetDigital
works
Digital Metronome
Preamps and Program
Delay Lines
X -Y Plotters
Amps
Sonipulse
Monitor Loud
Broadcast Consoles
Speakers
8460 San Fernando Road
(213) 767 -1000
Exclusive export agent: Gotham Export Corporation. New York
Sun Valley, California 91352
(7
Time -Align and its derivatives are trademarks of and licensed by
for additional information circle no. 25
www.americanradiohistory.com
E.
M. Long
Associates
(LEDE) LIVE END - DEAD END CONTROL ROOM ACOUSTICS ... (TDS) TIME
DELAY SPECTROMETRY ... (PZM) PRESSURE ZONE MICROPHONES
by CHIPS DAVIS
Las Vegas Recording
My original reason for attending Don Davis' Syn -Aud -Con
class in February, 1978 was to learn about TDS (or time delay
spectrometry). Little did know at the time that would take
Don's findings on the early order reflections in hard -front
control rooms and expand on the theory and make Las Vegas
Recording, Inc., the first Live End - Dead End (LEDE) control
room.
I
I
TDS
TDS was invented by Richard C. Heyser (U.S. Patent
#3466652) and requires a special license to practice.
Heyser conceived and patented this vast improvement on
pulse testing which had been in extensive use for 40 years,
and called it time delay spectrometry. Briefly described, the
receiver or tracking filters are delayed in time and do not start
the receiver sweep until the signal reaches the microphone.
This time delay sweep can then see the direct wave without
having any interfering room reflections. (60 dB of signal -toreflection.) It can delay the receiver and open the receiver
window for longer periods of time until the first reflection is
shown on the screen of the analyzer. The frequency, the
depth in dB, can be seen and the time delay can be calculated
to determine the surface from which the reflection came.
Tuning can continue out in time until there are no other
reflections, or the window is so wide only the total sound of
the room can be seen. TDS can also show the amount of
continued on page 44 ..
.
Those wishing a license to practice TDS should send a check for
S100.00 made out to California Institute Research Foundation, but
mailed to Syn -Aud -Con, and a check for $25.00 made out to Syn Aud -Con, for a set of "how to' notes on TDS. Syn -Aud -Con, P.O. Box
1134, Tustin, California 92680.
by DON DAVIS
Synergetic Audio Concepts
There are a series of fundamental "first principles" that
underlie the LEDE concept. When Chips Davis undertook the
redesign of his control room at Las Vegas Recording, had
only discussed the first of these principles
that of creating
narrower anomolies. What is of great interest to me is that
Chips in working out each new detail of the concept had
"felt" what we are now actually measuring and mathematically developing. It is our belief that artist -engineers like
Chips, when exposed to acoustical training, fulfill the
promise inherent in recording technology.
-
I
First Principles
What are the "First Principles" underlying the success of
the "Live end - Dead end" (LEDE) technique of recording
studio control room design? The answer to this query lies in
understanding how sound spectra propagate, reflect,
undergo absorption or transmission, and combine. This is
why you always see Time Delay Spectrometry (TDS) involved
wherever a LEDE control room is engineered.
Time Delay Spectrometry
TDS was developed (and patented) by Richard C. Heyser in
1968. TDS allows the user to observe the direct sound level
as if in an anechoic room with a 60 dB reduction of the signal
from any surface. Since conventional anechoic chambers of
first quality can only provide a 20 dB reduction it can be seen
that TDS is an extremely powerful analytical tool of
unprecedented resolution.
In observing the direct sound level with the TDS analyzer it
is easily seen that no "room modes" are involved, even
though the loudspeaker is indeed indoors because there are,
continued on page 52
.
.
R-e/p 41
www.americanradiohistory.com
.
£lomo
aaa
1I
1/
IL7/14.1...lAIAA7.17"771I47A trAlAp*iliI.LA
,II. IA.! Imi, /i0
r7r.. rr.. r.r.
... r.- r.rN» r7, Ar______-
...'__'v
..n&WW
.r
i
.
!.
loWrauMAe-
eiul/tA
YMmy''
/I
>>
7
LIVE END - DEAD END
(LEDE)
COAISOIE
1A
-
1B
- CONSTRUCTION
CONTROL
DEAD LOWER WALL BELOW
STUDIO WINDOW
Button board covered with fiberglass and
covered with carpet.
(Made to stand abuse.)
OF THE ABSORPTIVE
ROOM
END OF THE
Standard studio wall construction will be
followed. The absorptive battens will be
constructed as follows: 1/4-inch plywood
cut to width and length as determined by
the decorative design. Cover plywood
with R19 fiberglass. Cover fiberglass and
board with heavy cloth. The batten will be
nailed with paneling nails and glued with
paneling adhesive. Fire retardant should
be sprayed on all cloth coverings.
1C
'.-_'
A7
Mi'iIrü
W
LO¡A41M
A
`
ofv¡IlAlatnr.ì
')
A 4111116101,WA
I'-
1
t. t/
-
THE LIVE END CONSTRUCTION
Standard studio wall constuction shall be
used as with compliance to studio sound
and deadening techniques. Live end decorative finishing materials shall be of
real wood whether paneling or board
nailed and glued so as not
planking
to have any rattling or resonance effect.
-
1
í1. L.... .. I
(
1
_ÿ
..
iv
iG
iftpA> iAAal/A7/ milnl/LL1á
absorption various materials provide, the effectiveness of
splays and not only acoustical problems but anechoic
displays of speakers and microphones. An anechoic
chamber only has about 20 dB of signal -to- reflection; TDS
has 60 decibels of signal -to- reflection. Polar response of
speakers and front -to -back ratios of microphones can thus
be easily viewed with TDS. TDS is probably one of the most
useful tools available to us today to find and analyze
problems in our audio industry.
Live End - Dead End (LEDE) Control Rooms
Live end - dead end (LEDE) refers to the newly conceived
acoustical design for control of rooms. It seems to me that
this is the first real advance in recording studio control
room acoustics in quite some time. To quote Don Davis, of
Synergetic Audio Concepts, whose theoretical concepts of
LEDE developed through his work with time delay
spectrometry, those which compelled me to build the first
live end - dead end control room: Don wrote, "Pick up any
book with pretensions of knowledge about recording
studios and almost without exception the material on the
internal acoustics exhibits an enormous void of accurate or
useful information. Implied is that all you have to do is add
absorption with the aid of some devil's apprentice with info
from the dark domain and all is well."
LEDE is basically the complete opposite of all other control
rooms. That is, the rear of the room is hard and reflective
while the front is as absorptive as possible.
Let's start with the front of the control room, and explain
the reasons behind the absorptive half. Davis found, through
TDS, that mixing of early reflections from the hard ceilings
and walls of conventional control rooms with the direct wave
causes very deep anomolies in the order of 25 to 30 dB.
Anomolies are any deviation from the original response,
therefore, distortion.) These anomolies are broadband and
very deep when generated by very early reflections. They
occur from the low mid to the uppermost frequencies beyond
the audible range. The anomolies, from improper acoustical
design, are caused by addition and cancellation of signals
arriving at the mixing position out of phase, the phase
depending on the time interval or the distance of the early
order reflections.
The acoustical anomolies and anomolies due to improper
speaker design cannot be equalized into a smooth, flat
reproduction spectrum. To equalize a control room under
these conditions with the equalizing microphone at one
position (in the mixing position), you could obtain a
reasonably flat response. Move the microphone two inches
and the curve becomes a gross, mis- adjusted, unequalized
mess. Try this in your control room. Move the microphone in
the area of the mixing position and watch the response curve
change.
LEDE acoustical design minimizes this effect and helps
keep a uniform frequency response in the mixing position.
These anomolies are real and do exist in hard -front control
rooms. We can see these effects and mathematically study
their cause and effect with the aid of time delay spectrometry.
(
The Live End of LEDE
think, the most
The live end of the control room is,
important part of the room. Davis gives a demonstration of
the Haas effect in the Syn -Aud -Con class. It is a simple, but
R-e/p 42
www.americanradiohistory.com
I
Announcing
the new
672A Equalizer
8 bands + tunable filters
+
electronic crossover = $499*
.. -°
--
, =L.
.
-==
°
-
. J .....
'_'
:ç
The 672A is a fully professional 8-band single -channel parametric
with extra tunable highpass and lowpass filters. The filters can be
used to shape the response at the ends of the spectrum
Or. the
672A's split output lets you use the filters as a full electronic crossover cascaded with the 8 -band parametric.
At $499' it's an unbeatable machine for sound reinforcement,
monitor tuning or general purpose program equalization in
recording, broadcasting, cinema, theater, and disco.
Despite its attractive price, the 672A contains no quality compromises. Balanced input (with output transformer option), RFI
suppression, and state -of- the -art specs are all there, as are Orban's
traditional industrial quality, serviceablity, and comprehensive
software. Orban's advanced engineering and manufacturing
expertise are the keys to this extraordinary value.
Discover more about this remarkable, easy to use equalizer.
See your Orban Dealer or contact us directly.
ow001M...
-
-
'suggested list
orlan
Orban Associates Inc.
645 Bryant St.
San Francisco, CA 94107
(415) 957 -1067
4
for additional information circle no. 26
www.americanradiohistory.com
R-e/p 43
sound absorbing battens
i
LAS VEGAS RECORDING
"LIVE END
Hardwood
-
DEAD END"
,,..
"1i
Front View (from back wall)
Live End
Side View
110/
a
/
,/
r
w 4Lut,
,
f
,3
dlq,
a
Y:l
=1
-
i.¡
;.r.
r
r
"kJ1.r1_`_.
Carper
very important fact of the LEDE control room. The Haas effect
is the ability of the brain to discriminate against echoes and
delays of sound that arrive approximately 10 to 20 msec after
the original waves. The sound is still present but psycho acoustically does not exist so far as the listener is concerned.
If the listener is 10 feet or less from a wall, the sound wave
travels past him to the hard wall and back- a total of 20 feet
and he will not be aware of its origin. This is called the
Haas effect. At greater distances the listener hears echoes or
flutter. A hard -backed wall that is 10 feet or less away does
not acoustically exist in our brains. The brain doesn't
recognize or receive it. Again, this is the Haas effect.
Therefore, we have, for the listener, eliminated the back
wall, an infinite distance in space, psychoacoustically, and
all we can hear is the front speakers.
Control rooms with very dead back walls compound other
problems: room acoustics, speakers, and sloppy studio
construction. Now that we have a disappearing back wall, we
have to treat it acoustically, and this is where everything
becomes like a game of acoustic pool at 1,130 ft. per second.
-
Dead End
Live End
We splay, angle, direct and bounce the sound that strikes the
rear wall back to the mixing position. This stacking of the
immense number of reflecting paths from the back wall is
very precise and is figured extremely close as to time
interval.
What we are trying to achieve is a very dense and diffuse
total sound spectrum by combining the paths off the back
wall into a series of controlled narrow band comb filters.
Successfully done, the overall result is a very smooth total
sound spectrum without any broadband anomolies. This
procedure also masks console reflections, tape machines,
people, etc., so that what is heard by the mixer is true,
extremely accurate sound.
If the back wall is designed incorrectly, the possibility of
having reflections arrive outside the 20 msec time interval
would be disastrous. Inside the 20 msec range, an initial
time delay gap of a much larger room is present at the
mixer's position. You can turn and face the rear wall, cup
your ears, and none of the sound from the monitor speakers
ever seems to come from anywhere but the monitor
NEOTEI4eostern &s.w.; u.s.
No matter what console you
are considering, you can't get
a cleaner board or a better
dollar value than a Neotek
SERIES III.
a
full line studio design- construction company.
./tisi. Audio
Associates
3P Bonnaview Dr.
Nashville, TN 37076
R.e/p 44
The fully professional SERIES Ill is
available configured up to 40 inputs
with 32 track assignment. Each module
contains a full 4 band quasi parametric
equalizer & light meter level indicator.
Neotek is the pioneer & leader in
transformerless console design.
Call Bill Wilson and let us put our
years of experience to work for you.
615-883-1405
for additional information circle no. 27
www.americanradiohistory.com
Stressing Quality
Orange County Electronics, creators of fine professional audio products for over a decade, introduce the
new VS -1 Stressor. The VS -1 combines the separate
functions of a compressor with adjustable ratio, threshold, and attack and release times, a fast peak limiter
with 250:1 slope, and a highly functional expander/
noise -gate, and a full parametric equalizer, all in one
beautiful 3'-':" rack mount.
This complete signal processing system gives you'the
power to handle problems such as level control, noise,
and equalization in one package. These necessary processing functions are designed to work independently
or in tandem with one another. For example, with the
selection of one button which handles routing chores,
the parametric equalizer can be inserted before, after,
or in the side-chain of the compressor. When in the
side-chain mode, you have a frequency-sensitive compressor or dynamic equalizer, which can deal with
sibilance problems on vocal tracks as a "de- esser."
The Orange County VS -1 Stressor is built to high
technical standards and offers switchable balanced/
unbalanced operation, with fully modular construction
for easy service and performance flexibility, and noise
and distortion specs equal to the best in the industry.
Applications for the VS -1 Stressor include recording
studios, AM broadcasting, TV and broadcast production, film sound, and sound reinforcement. Quiet,
powerful, and extremely versatile, the VS -1 Stressor
belongs in your studio or station today. And for smaller
studios or stations who want the fine sound of the VS-1
but don't need the full flexibility, try our VS -2 Stressor,
which offers internally pre -set functions.
10
10
COMPRESSOR
LIMITER EXPANDER
-
EXPANDER GATE
PRESSOR
0.lID
INPUT
RELEASE
TNfES1gfD
-1
DIPA
IN
OUT
ON
OFF
2.5
-- _
RANGE
ns
r111
0
7
--
25n
120FF IZO
2
b
@
G
PEAK
PEAK
YS,
PEAK LIMIT COMP ATTACK EXP /GATE
SYSTEM
3K5
r---
5K
COMPRESSOR
11
2
EXP ATTACK
/in
3
RELEASE
OUTPUT'
,,
fOWtr r.tCK11,0o`'
OUASE O
l)
ORANGE COUNTY ELECTRONICS
INTERNATIONAL INC.
Exclusive Sales & Marketing:
Pak-bound
680 Beach Street, San Francisco, Ca. 94109 (415) 673-4544
Dealer Inquiries Invited
for additional information circle no. 28
www.americanradiohistory.com
Rc/p45
THE BEST VALUE
IN A PROFESSIONAL
TAPE RECORDER
When you compare a tape recorder, here are the most important
areas to consider for value, quality, and sound.
PERFORMANCE:
Overall Signal -to- Noise: 66 dB unweighted at 520 nWb /m (30 Hz to 18 kHz audio fitter).
Playback Signal -to -Noise (electronics): 72 dB unweighted (with audio filter).
Headroom: -24 dB.
Maximum Output: +28 dBm.
Overall Frequency Response (15 ips): 30 Hz to 22 kHz ±2 dB.
Playback Frequency Response (MRL test tape): 31.5 Hz to 20 kHz ±2 dB.
An unmatched 4 -year track record of on the job performance for the original compact
professional recorder. Day in. night out. Just ask someone you trust.
RELIABILITY:
Any tape recorder must be aligned to achieve maximum performance. With the
including record bias and level are on the front panel. So is a 1 -kHz test
primary
alignments
all
MX- 5050 -B,
it fast
oscillator. Secondary alignments are inside the bottom panel. You or your maintenance people can align
ALIGNABILITY:
and easy. This saves you time, money, and enhances your reputation.
INTERFACEABILITY:
With a flick of the output switch you can plug -in to any system:
No line amps or pads to mess with. A perfect match everytime.
impedance.
+4 dBm 600 ohm or -10 dB high
ADDITIONAL BENEFITS:
Three speeds, dc servo ±7 %, 1/4 track reproduce, full edit
including indexed splicing block, over-dubbing, noise free inserts, XLR connectors, NAB /CCIR switching.
unique 3- position alignment level switch.
PRICE:
Suggested retail price $1,945 (USA).
MX- 5050 -B: THE CHOICE IS OBVIOUS
immi
Call Ruth Pruett on 415/593 -1648 for the name of your nearest Otan professional dealer.
Otan Corporation. 981 Industrial Rd., San Carlos. CA 94070 TWX 910- 376 -4890
416/675 -2425
In Canada: BSR (Canada. Ltd.). P.O. 7003 Sta. B. Rexdale, Ontario M9V 4B3
www.americanradiohistory.com
_
__
se
MSCOMO
1147(606p
,,,
r
ÿ-. ..r
'
.r
or
r
r. ..
,
o
CMS SYS
41111mg.
'4s
osc
cH
TOO
-
O
for additional information circle no. 12
t
MON
R
www.americanradiohistory.com
p 41
...
continued from page 44:
speakers. It is totally undetectible in direction but audible in
level. Careful diffusing of the rear wall and a very soft, nearly
anechoic front wall are what makes an LEDE an incredible
mixing environment. You have complete control of placement, depth and locality.
Time Alignment of the Monitors
LEDE and TDS are what we have put together so far. Now
we will add time align" (trademarked by E. M. Long
Associates) monitor speakers invented by Ed Long and Ron
Wickersham
the UREI 813s.
The 813s give a realism in the LEDE control room like we
have never encountered. Before having installed the UREI
813s, we had a very popular, well known monitor. After
looking at this speaker with TDS (See Figure #1) we decided
-
Figure I. Studio monitor which exhibits a series of severe
acoustic anomolies. Measurements made with TDS.
to go to the 813s. Comparisons proved the 813s far superior
due to the problems of mis -time alignment caused by misdesign of the crossovers. The problem cannot be easily
eliminated acoustically or electrically. This distortion in the
old monitor speaker could readily be heard by placing your
hand over the tweeter and hearing the anomolies that we
were seeing on the analyzer disappear. (See Figure #2) This
Wickersham and Ed Long and manufactured under license
by Ken Wahrenbrock, under the trade name PZM"
(trademarked by Syn -Aud -Con).
If you don't have an LEDE control room, or 813 monitors to
A - B any mike in your arsenal, don't worry. The PZMs will
give you a realism that will really make you a believer. Try it
on anything. A - B it with any mike, in any situation
piano
is the most startling. Lay the PZM on a hard surface, on the
floor, tape it to a baffle, tape it on a wall or under the lid of a
piano
or tape two, one above the "f" holes and one down
by the bass strings. This is the most incredible stereo piano
you have probably ever heard. Horns, drums, vocals
all
take on new realism. Some of the comments that I have
received from some of the very fine trumpet players and
musicians is that it is like playing against a solid concrete
wall and hearing themselves come back, or a direct disk
recording of themselves. Put your favorite vocal mike up for
vocals and put the PZMs on a flat surface up to 3 or 4 feet
away. (See Figure #3) Run one to one track, the other to
-a
-
-
Figure 3. Pressure Zone Microphone (PZM' "). A pair of
Pressure Zone Microphones sells for $225 with power supply.
another. When you get through, A - B them. See which one
the performer likes and see which one you like. If you don't
believe the sound that you're hearing, go out in the studio
exact realism.
and put your ear exactly where the mike is
-
Putting It All Together
Figure 2. Studio monitor response when the H.F. unit is
covered with a hand.
distortion is due to two elements emitting the same
-
-
the mid -range and the
frequencies from different planes
with the crossover not cutting the mid -range off
tweeter
but allowing it to share a mutual portion of the spectrum with
the high frequency. The effect is readily detectible and the
ears can hear the distortionon cymbals and mid -range upper
spectrum. You can hear the crackling of the anomolies as
they phase in and out, causing the distortion feeling in your
ears after you know it is there and focuses your attention on
that particular section of the spectrum.
-
PZM
Pressure Zone Microphones
Having eliminated the problems of the speakers and the
distortion of the early order reflections that caused
anomolies we then added another improvement to our
medium: The Pressure Recording Process (PRP"
trademarked by E. M. Long Associates) is a new type of
microphone and miking technique developed by Ron
-
When LEDE, TA, PZM and TDS are put together we have
produced the most accurate mixing environment that we
have had in the studio to date. It is so clear, and free of
distortions caused by anomolies, mis- designed monitors,
and general smearing of bad control rooms that your ears
start to rebel. Where is that old sound of distortion, problems
that everyone has accepted for many years? Your ears have
learned a new realism that you can only experience from live
naturalness of drums, tympanies, trumperformances
pets, English horns, oboes. have a good comparison for that
it's live orchestras, 40 weeks a year, seven days a week.
A large number of engineers have been through the new
LEDE room at Las Vegas Recording. If you're near Las Vegas,
I'll be happy to have you stop in.
What we have to look forward to now is an LEDE mastering
room, digital recording and improved record processing. It is
extremely difficult to put into words what these advancements can do for our industry, but I'll sum it up by answering
the question that has been asked of me many, many times by
the people who have come through our facilities: "What
have you gained, if the material is to be played over AM radio,
cheap hi -fi sets and television ?" My answer to this has
always been the same, "Every problem is additive, all
they never subtract from each
problems add together
other. They combine to make larger problems. Any problems
that you can eliminate anywhere in the chain and make your
product better will always be better, played anywhere,
anytime, over any system."
-
R-e/p 48
www.americanradiohistory.com
-
I
-
Audio-Tcchnica
rcwritcs the book
on profcssional
phono
cartridges.
Introducing
The Professionals
The new
Audio-Technica
ATP Series
Dual Magnet Stereo
Phono Cartridges
The all -new ATP cartridges were
specially developed for the working environment. Three models
provide a choice of either spherical or elliptical styli. Each cartridge is hand -tuned for optimum
performance, with stereo channels matched within 1.5 dB to
eliminate balance problems.
All ATP cartridges feature
tapered cantilever tubes that
combine high strength with minimum moving mass. There's no
problem with back cueing, and
the brightly colored cantilever
tip is readily visible so that you
can spot an LP cut quickly and
accurately.
What do you really need from a
professional phono cartridge?
Impeccable quality. Reliability.
Uniformity. And reasonable cost.
The goals we've met with the new
ATP Series cartridges.
The new ATP Series are flat, smooth, low distortion performers that will do your station, studio, disco, library, or
commercial installation proud. They are also very tough...
the next best thing to "bullet proof'. Because we know
that "needle drop" isn't just a way to pay for music or
SFX. It's a fact of life!
ATP cartridges are priced from $30.00 suggested professional net. Write for complete specifications. Try the ATP
Professionals on your own turntables. We know you'll be
pleased with what you hear. From the thoughtful pros at
Audio -Technica.
Both ATP cartridges and styli are uniformly excellent.
When you at last need to replace a stylus, you always get
"like new" performance again, and again, and again.
Don't confuse the ATP Series with other "professional"
cartridges that are merely modified home units. ATP units
don't have to be treated with kid gloves. And yet we haven't
sacrificed tracking ability to make them rugged.
Upgrade your entire record -playing system with new ATP tone
arms. Rugged and precise, like ATP cartridges. Professional
in every respect. Model ATP -12T or ATP -16T just $125.00 suggested professional net.
audio technica.
INNOVATION
PRECISION
INTEGRITY
AUDIO -TECHNICA U.S., INC., Dept. 19RE, 33 Shiawassee Avenue, Fairlawn, Ohio 44313
for add,t,onal Information circle no. 29
www.americanradiohistory.com
In
Canada: Superior Electronics, Inc.
R-e/p 49
OUR
VARIABLE
SPEED CONTROL
WILL MAIE
YOU CHANGE
YOUR TUNE.
If you're already
working with an 80 -8 or
40 -4, our Variable Speed
Control is a very cost -effective
addition. For just $350* you'll
adjust 15 ips to the tune of ±20 %.
And you'll get a brand new
single speed servo -controlled
DC motor in the deal. Your
multichannel recorder becomes
more versatile. And it ends up last ing longer. Remember trying to over-
www.americanradiohistory.com
,
dub a piano only to find it out of
tune
with the track? Or sweat-
r
through three hours with a
singer who flatted the last note of
an otherwise flawless performance?
You'll turn these late -night horror
stories into lullabies with Variable
Speed Control.
Try it for adding a "tunable tom"
effect to your song. Then experiment
with other rhythmic twists.
Turn two singers into a chorus
of eight. Add harmonies. Transpose
from A up to C, or
back down to
ing
i
the 80 -8,
you have
eight tracks to build your song.
When you're working with
synthesizers, you can spend
hours experimenting. Or seconds repairing an out -of-tune
tone. Try creating your own
special effects, bending and
shaping other instruments to fit
your ideas. Whether you have an
80 -8 or 40 -4, you have the
capability to turn basic music
into complex arrangements.
As a production aid, our
Variable Speed Control becomes
Executive Producer when that
beautiful radio spot comes in at 32
F #.With
seconds. Just rewind the tape, set
the control and 28 seconds later
you're right on the money.
For audio -visual soundtracks,
slide or filmstrip audio tracks,
Variable Speed Control lets you solve
tough cueing and timing problems.
Without re- recording,wasting time
losing money.
and
,
i
If you're still thinking about
buying your 80 -8 or 40 -4, now is an
ideal time because you have the
option of taking it home with
Variable Speed Control and new DC
motor completely installed.
Let your Tascam Series dealer
give you a hands -on demonstration.
You'll hear how our new Variable
Speed Control lets your 80 -8 or
40 -4 sing a new tune.
40-4
TF
TEAC
80-8
-
-
TEAC
TASCAM SERIES
TEAC Professional Products
TEAC Corporation
for additional information circle no. 30
of America, 7733 Telegraph Road, Montebello,
CA 90640.
R-e/p 51
www.americanradiohistory.com
DON DAVIS
... continued
from page 43:
a compression and in the other case it starts with a
rarefaction. So let's clarify the terms "polarity" and "phase."
(No Charlie
you don't "phase speakers" by reversing the
connection to one of them.) Polarity is not frequency
dependent; Phase is frequency dependent. A polarity
reversal is instantaneous in time where a phase difference
involves a time difference. In fact, there is a simple equation
for translating phase difference into time difference
TI) = TpO
360
with
EFFECT OF TIME - DISTANCE ON AMPLITUDE RESPONSE
-
TIME DOMAIN REPRESENTATION
21
51
/
Where:
CI
one wavelength at frequency
the time delay, or difference, in seconds
the time period of frequency f (Tr, = 1/f)
() is the phase delay in degrees
TD is
1
Tp is
LK
Then, of course,
O = T1)/Tp
21
FREQUENCY DOMAIN REPRESENTATION
f
I
4f
3f
21
etc
f
eq e cv
I
ea
sweep
For deliberate displacements of "acoustic center"
TI) = ((1 sec /1130 ft) (1 ft/12 in)) (displacement in inches)
Using these concepts we can calculate that two source;
emitting the same spectra but with one of the units one inch
behind the other.
Tn
5f
151
2 51
3 51
4 51
(360)
=
(1/1130)
(1
/12) (1")
=
.0000737 secs, or 73.7 µsecs.
etc
as yet, no reflections. Room modes are the resultant
amplitude variations by frequency as measured at a given
position of the complex additions of time varying reflected
spectra with each other and the direct sound. In other words,
"modes," or more properly, eigen- wavelengths (for it is their
wavelengths that remain consistent as, for example, when
the temperature shifts) are frequency response anomolies
generated by reflected spectra. Figure #1 illustrates simple
combinations that can occur. TDS allows the easy observation of this phenomenon because of the linear frequency
response scale of TDS in distinction to the "log" scale
universally used on standard frequency response charts.
The anomolies generated by two spectra arriving at the same
point in space are "out of phase," that is, displaced slightly in
time, are linearly spaced nulls and peaks in frequency. See
Figure #2.
The temporal integration window of the ear has an
effective width of about 10 to 15 msecs. Therefore, it might
be argued that such a slight time delay should not be audible.
What is forgotten is what this "phase shift" (which is what
time delay is) causes the amplitude response to do.
Figure #3 illustrates a frequency response from 0 to
20,000 Hz of the summation of the acoustic output of two
loudspeakers (1" apart) at the measuring microphone.
Please believe that the hole created is audible when program
material falls in that region of the spectrum.
Figure 3: Illustrates a frequency response from 0 to 20kHz of the
summation of the acoustic output of two loudspeakers (1"
apart) at the measuring microphone.
Figure 2: The anomolies generated by two spectra arriving at the
same point In space "out of phase ", that Is, displaced slightly in
time, are linearly spaced nulls and peaks in frequency (0- 20kHz)
A Short Primer on Phase and Polarity
Many audio engineers accept the statement that "reversing the polarity of a speaker shifts its phase 180 °."
If you examine the statement for a moment you will see
that the signal emits from the same point in space with
either polarity. The difference being that in one case it starts
Back To LEDE
Whenever the sound source and a pseudo source (such as
a virtual image generated by a solid reflective surface) come
together with a time difference of 73.7 µsecs or at a
frequency of 6780 Hz, a phase difference of
O =
((.0000737)/(1/6780)) X (360)
=
180°
Thus, you will have a large null in the response.
Now, let's place the two sources 10" apart. That is, one
source reaches your ears 10" ahead of the other source. See
Figure #4. We now have peaks at 1356, 2712, 4068, 5424,
R-e/p 52
www.americanradiohistory.com
These are the "big
guns" in "professional"
power amplifiers. Each
of these amplifiers has
individual features and
abounds with
specifications to impress
potential buyers and to
satisfy the professional
user but they are not
created equal...
especially in reliability
under professional (rack
mounted) conditions.
Some of these "big
gurs" have been talking
about everybody else
being "behind ", others
are talking about
comparator LED's, while
others depend mostly on
their good looks. The
continuous professional
other companies spend
a lot on cosmetics but
not much on built -in
forced air cooling and
large numbers of output
devices :o enable
reliable rack mounted
operation under
use.
Each channel of the
Peavey CS-800 features
10 output devices and 2
TO -3 drivers bolted to
massive modular
heatsinks that are forced
cooled by a 2 -speed fan,
has special distortion
detection circuitry and
LED indicator (not
simple overload), as well
as a functional patch
panel on the rear to
facilitate the use of plug in balanced transformer
modules, electronic
crossover modules and
speaker equalization
modules custom tailored
to Peavey's SP -1 and
SP -2 speaker systems.
In comparing pro
amplifiers, one should
apply the old
commercial sound
"dollar- per -watt" rule.
The CS -800 is again "on
top" at 81C per
professional watt. The
Peavey CS-800 comes
out on top when you
consider the features,
the specifications (which
are as good or better
fact is Peavey is not
behind anyone in power,
durability, features or
performance.
Below are the
respective published
specifications of the
"heavies" in pro amps.
Check for yourself to
see how we all stack up.
You might be surprised.
thar anybody's), total
power output, and price
per watt of professional
power.
Some companies
have recently
"discovered" LED's and
comparator circuitry that
Peavey pioneered and
has oeen using for
years. These recent
"corverts" were most
vocal in the past against
LED s...that is, until they
updated their "plain
Jane" units. Some of the
Peavey Electronics
Street
Meridian. Miss. 39301
711 A
HOHN DO THE "DIG GANS"
ST/WC UP?
0,.
0
r,
OE.4).
Peavey
CS-800
800 w Total
400 Watts/Ch
(' 4
20
2
Speed
ves
torced air
cooling
Ohms
Totally
Plug -in
/qC
310 W
DC -300A
155 W /Ch
Çd_8
16
Conventional
No
Hard Wired
Passive
Ohms
750 B
720 W Total
360 Watts 'Ch
(rN 4
4;),440s
Quasi Complimentary
All rugged NPN
Silicon Outputs
Not given
No accepted
Measurement standards
Presently exist
$649 50
None
R equ u ed
Quasi Complimentary
All rugged NPN
Silicon Outputs
0035% INTIM)
Crown is
quoting Noise
$899 00
Airflow Only
20
2
Speed
Yes
Modular
forced air
cooling
Relay Circuit
225 Watts Ch
Collector dme
Complimentary
02v5
No measurement
using PNP 8 NPN
Silicon
details given
Emitter follower drive
complimentary using
PNP 8 NPN Silicon
Not given
No accepted
Measurement standards
Presently exist
$1.79 per Watt
Based on
4
Ohms /Ch
n. in
load
(recently revised
Intermodulation
Distortion
Ohms
$0.81 per WW1
Based on
4 Ohms Ch min load
Transfer
500 W
250 W /Ch
@ 4 Ohms
BGW
Pq
None
Requi ed
Modular
260 Watts -Ch
C' 8 Ohms
I8oth Ch driven)
Crown
r/y
specs/
$1099 00 $1.53 per Watt
Based on
4 Ohms Ch min load
@ 8 Ohms
Yamaha
P 2200
700 W Total
350 Walts/Ch
(ie 4
Ohms
12
Conventional
Passive
Airflow Only
No
Hard Wired
None
Required
200 Watts /Ch
(a` 8
$1095 00
$1.56 per Watt
Based on
Ohms Ch min load
4
Ohms
All above figures based on manufacturers published specifications and minim/m recommended load impedances as
of 11.1/78
for additional information circle no. 31
www.americanradiohistory.com
adjusted the initial time delay gap to the same figure that
Beranek judged as desirable in the best concert halls in the
world, namely 20 msec. It is no coincidence that the same 20
msec is the optimum delay for the maximum Haas effect in
good diffuse semi -reverberant spaces. See Figure #5.
Figure
5
INITIAL DELAY GAP
STUDIO
Figure 4: Two loudspeakers 10" apart. One source reaches the
ears 10" ahead of the other source.
6780 and 8136 Hz, and nulls at 2034, 3390, 4746, 6102,
7458 and 8814 Hz.
What is of fundamental interest is the fact that the greater
the time difference (or distance) between two combining
spectra, the narrower the response anomolies generated.
I'm sure we are all familiar with the concept that the wider
the bandwidth of signals (at the same level) the greater the
power. For example, one hundred watts as a sine wave will
reach a far higher level on the analyzer than a 100 watt pink
noise signal as the filter reads each spectrum. Thus the
familiar caution, "the wider the bandwidth, the more likely to
cause problems."
Only a short period of time is required before the
investigation of response anomolies leads to an understanding that small time differences are not desirable in control
room acoustics. How do we get rid of such early differences?
Put the sound source in as nearly anechoic space as you
can achieve, but in a manner that insures that the reflected
sound travels 15 to 20 feet further than the path taken by
the direct sound from the source.
Making a Physically "Small" Room
Into An Acoustically "Large" Room
When the "source" end of the control room is made nearly
anechoic it insures, so far as excitation by the sources
located in the anechoic end are concerned, that the earliest
reflection the ear will hear now has the time dimension of a
much larger room. So, too, the diffusion at the "live" end is
able to be manipulated so as to approach both the narrow
band characteristics as well as the density characteristics of
a much larger space than actually is on hand. In other words,
all clues, acoustically speaking, have been removed or
masked that would allow aural identification of the physical
size of the environment. Beranek has written in Music,
Acoustics and Architecture (page 26):
for example, blind
Persons trained in listening
people, who receive all their cues about the environment around them through the senses other than the
eye
can "measure" the size of a room or judge the
distance to a wall behind them by the length of the
time interval between the direct sound and the first
reflected sound.
Beranek goes on to note that this capability is not
restricted to the unsighted but that
Experienced music listeners ... sense the approximate
size of a hall ... by the length of the "initial- time -delay
-
-
INITIAL TIME DELAY
=
TOTAL
OE
REFLECTIONS
-
DIRECT SOUND F
J
There are two important factors both in the control room
and in the concert hall. They are:
1
- The first substantial reverberant energy when in
the Haas precedence zone does not distract the
listener with "directional" information but merely
raises the acoustic level.
2 - This early arriving reverberant energy must be
well diffused if the aural mechanism is not to fasten on
a specific clue. That is, the energy should arrive over a
spread of time that does not allow identifiable broad
band anomolies to be formed by only a few discrete
reflections combining with extremely short differences in travel time. A mixture of a goodly number of
reflections spaced over, say a time interval from 15 or
the RT, of the "live"
20 msec to 300 or 400 msec
is the design goal in a really high
end of the room
quality control room.
All enclosed spaces theoretically have a reverberant
sound level. Figure #6 illustrates the sound fields theoretically present in a control room. First, there is the direct sound
level from the source. Second, there is the total reflected
reverberant sound level. This reverberant level may consist
of merely a few discrete reflected spectra or it may be a well established diffuse field. Third, there is the total sound level
the direct and reflected sound levels combined. Finally,
there is a sound field not generated by the sound source
under consideration, called the ambient noise level. All of
-
-
-
-
these sound fields require consideration when discussing
any part of the total sound individually.
In control room work, because of a mistaken use of a
technique useful in large rooms (arenas, etc.) but incorrect in
small rooms, many control rooms do not have a reverberant sound level capable of influencing the total sound
level. In other words, for all practical purposes there is no
reverberant sound field present because the total sound field
level is identical to the direct sound field level.
The LEDE technique, by virtue of the distance the direct
sound must travel to encounter a first reflection has
R-rip 54
www.americanradiohistory.com
continued on page 58
..
.
Studio Supply
Won't Stay
In
One Place!
They are in Nashville! Now they are in Miami! They
are on the move to better serve you! And have they
got a new line
Sound Workshop Professional Audio
Products! STUDIO SUPPLY is where you need them
with the best equipment!
-
for additional information circle no. 32
www.americanradiohistory.com
R -e /p 55
What do you look for
in a Recording Studio?
Whether you are looking for studio
time, equipment or design, you owe
it
to yourself to find out what
"The Gold Record People"
can offer you.
:, _...1Q'fA-
www.americanradiohistory.com
r
f
as
. . ... e.r
Wea
e,
Audi
www.americanradiohistory.com
6311
Wilshire Blvd.
Los Angeles. California 90048
12131 655 -0303
8447 Beverly Blvd.
Los Angeles. California 90048
1213) 654.2155
...
continued from page 54:
Figure
DEFINITION OF ACOUSTIC TERMS
7
EFFECT OF 'DEAD' REAR WALL
Calculated
Total Sound Level
Direct
Sound
Level
Calculated
Critical Distance (D,)
-0.
2D, (Calculated)
/316D,
d8
=
iú
.d8
Surface Absorption
Material 'n' = 99
4
Calculated
Reverberant
Sound Level
m
LOUDSPEAKER
O
10
(Calculated)
Total Sound Level
O
.1dB
=4
Total Sound
Level AdB s 5.6
Reverberant Sound Level adB
--
=
M
`
3511
1
99
/
64 9
If
a
- Ambient Noise Level
-4.
¡1
total Sa= 440 then loudspeaker will generate
reverberant sound field level comparable to
that which would appear in a space having
440 X 64.9 = 28.556 Sa
4
-- Reverberant Sound Level .1dB
,
=
5 66
Distance From Sound Source (log scale)
Figure 6
How A Control Room Can Be Anechoic To
Its Monitor Loudspeakers While Remaining
"Live" To The Mixer's Ears
First, consider if an anechoic chamber would make an
acceptable control room. This question is easily answered by
trying to mix in a chamber; a really horrible mix results. Or it
can be seen theoretically by considering the massive
anomolies that would be generated every time you moved
your head from precisely between two monitors. Experience
reveals that you wouldn't want to "mix" in a reverberation
chamber either. Thus we have eliminated the two limits
available. Obviously, the answer lies somewhere inbetween
and is called the semi -reverberant sound field.
A semi -reverberant sound field is characterized by a
reverberant level capable of influencing (favorably) the total
sound level without having to be the predominant level.
Figure #6 illustrates the effect.
One way to thwart the establishment of a semi- reverberant sound field that is quite often done without realizing the
severe consequences is to make the wall behind the mixer
"dead." See Figure #7. If, for example, there were a total
absorption of 440 sabins (Sá) in the control room, so far as
the loudspeaker is concerned, there are 440 x 64.9 = 28,556
Sá, while the mixer continues to hear a semi- reverberant
space for any of the sounds he makes. At mid -frequencies a
UREI 813 hasa Qin excess of 10(which, by the way, is nearly
but that's a discussion longer than this article). A
optimum
"live" talker has a Q= 2.5 at mid -frequencies. Therefore, in
this case the loudspeaker will not generate a useable
reverberant level.
In large rooms (auditoria, arenas, etc.) we attempt to
increase M, (architectural acoustic modifier). In control
rooms, we attempt to eliminate M, and concentrate on
maximizing diffusion in the "live" end of the room.
-
Some Comments On Reverberation
The above mentioned "diffusion" constitutes the heart of
LEDE design and is a subject that, from the evidence in the
literature of control room design, is not sufficiently
understood. To properly cover the subject of diffusion
requires more time and space than this article affords. For
those with pressing needs, the writings of A. M. Legendre
and C. F. Gauss on quadratic- residue sequences of
elementary number theory have been found germane by the
most qualified of modern researchers into the problem.
Much confusion attends the term "reverberant sound
field" in the control room. Theoretically speaking, any
enclosed space has a reverberant sound field. The only
difference between one space and another space is the
sound level of the reverberant sound field.
To again look at "limits," an anechoic chamber has a
"reverberant sound field" that is, by specification, down 20
dB below the direct sound field level. In any practical case,
using the best of the currently available acoustic measurement equipment, an accuracy of 0.5 dB is exceptional;
therefore, any reverberant sound field level found to affect
the total sound field level by less than 0.5 dB may, with
justification, be treated as not present. This is particularly
true whenever the measurement of the total sound field
level is being taken at a distance from the sound source that
exceeds twice the calculated critical distance, D,. See Figure
#8.
We have found that the desired MB falls between 3 and 4
dB. An extremely simple but highly effective estimator of
MB is the Peutz equation
dB
=
.22
((fV)/(h-RT.))
Where:
V is the internal volume of the space in
h is
RT,,
ft'
the height of the ceiling
is the reverberation time for 60 dB of decay
We use the equation in the form of
RT,
=
.22
((V)/(h-MB))
Advantages of the LEDE Concept
What LEDE accomplishes acoustically can be enumerated
as:
1 - Frequency response anomolies generated by the
interaction of the direct sound and first reflections are
high density narrow band (less than 1/6-octave at 500
Hz and 1/12- octave at 1,000 Hz, etc.).
2 - The initial time delay gap (as defined by Beranek)
may be adjusted to provide the psychoacoustic effect of
a large space.
R-c/p 58
www.americanradiohistory.com
0
0
0
0
(Calculated)
20, (Calculated)
D.
m
d
_1dB
Calculated
Reverberant
Sound Level
=
5 5
Direct Sound Level
_
Actual Reverberant
Sound Level
- - - --
-
-
-
Ambient
-
000000
Distance From Sound Source
Noise Level-
+Total Sound Level
-
Actual Total Sound
Level
5dB
--- - - -_
Conclusions
Figure 8
Figure #8: Sound Levels
The sound levels normally measured with a sound level meter are:
- Direct sound level
2 - Reverberant sound level
3 - Ambient noise level
4 - Total sound level.
Expressed mathematically the non- coherent addition of the first
three constitutes the fourth.
1
T,i
=
10 log (exp(D,i
/10)
+
exp(R,1
/10)
+
exp(ANL /10))'
The addition of individual frequencies can be accomplised by
T
_
10 log v/(exp(SPL,/ 10)exp
=
+
(exp(SPL-/ 10)): + 2(SPL, XSPL,)(cos(a, -a,)'
base 10
Where SPL,, SPL, is the relative sound pressure associated with
sound level
10(D,i /20)
7 - Spatial geometry is not degraded by the control
room environment and therefore remains dependent
upon:
A - Loudspeaker spacing and orientation (10 to
20 feet are suggested separation distances).
B - Time alignment of loudspeakers.
C - Pressure Zone Microphony, PZMI". Suggested microphone spacing just slightly wider
than playback loudspeaker spacing used.
D - One fundamental advantage of LEDE that
can be overlooked is the fact that equipment
racks, tape machines, etc., when placed in a
soffit flush with the upper rear wall now provide
useful diffusion of the higher frequency energy.
The LEDE concept of control room design is part of a chain
of events that leads to "coherent sound reproduction."
1
- TDS analysis of direct and reflected spectra.
2 - Enlightened use of actual Time Aligned'" (E. M.
Long Associates) transducers. (Be very wary here as a
majority of the devices claiming TA are not so aligned.)
Enlightened use of the PZMI" system.
4 - Creation of a desirable "acoustic size" control
room free of uncontrolled response anomolies.
5 - Creation of a diffuse "live" end adjusted to an
3 -
effective CAB.
6 - Use of combinational geometry in the creation of
eigen wavelengths of the desired spacing and density.
7 - Use of the psychoacoustic effects of precedence
(Henry, Fay -Hall, Haas, et al) and intitial time delay gap
(Beranek).
Chips Davis is the first recording engineer to use PZMI ",
TA, and LEDE, in a control room analyzed by TDS.
N eve
a
=
a,: a: are the phase angles in degrees associated with SPL, and SPL:.
It is important when using sound level meters, spectrum
analyzers, etc., that the operator knows how to detect which of these
levels or combination of levels he is measuring and knows how to
calculate the others from the ones measured. Quite often the total
sound. including ambient noise, is mistaken for the reverberant
sound level. On occasion critical distances are discovered in
essentially non -reverberant spaces and incoherent signals are
summed as coherent signals.
Figure #8 helps define some of these terms and illustrates their
relationship. The case chosen is a control room which for all
practical purposes may be considered without a reverberant sound
field. The actual reverberant level is so low as to make the total
sound level at 2D, (calculated) less than .5 dB different than the
direct sound level at that same distance. Since the room is only 40
feet in its longest dimension, the reverberant sound level, though
theoretically present, does not affect any measurement undertaken.
3 -
All first order reflections fall within the Henry -
Haas effect precedence zone.
4 - Substantially more acoustic energy can be
developed without incurring the penalty of "small
space" coloration.
5 - Symmetry need not be as rigorously enforced
provided no repetitive reflection paths are established
(control of flutter, echoes, etc.).
6 - A sufficiently reverberant sound field may be
developed to generate a OdB of 3 to 4 dB while
maintaining traditionally accepted reverberation
-
DEALERSHIPS AVAILABLE
FOR NEVE
LYREC
Neve, the world leader in professional audio consoles and computer assisted mixing systems, is
seeking dealer representation in the following areas:
MIDWEST SOUTHEAST
SOUTHWEST ROCKY MOUNTAIN
Applicants should be experienced in selling professional audio equipment to sound recording and
broadcast fields, and should have first -line service
facilities. This is an excellent opportunity for a
hardworking dealer to increase its yearly turnover
potential significantly. Please reply in strict confidence with brief details of your sales area, turnover,
growth history and current products carried. Sorry,
NO dealerships availabile in the Northeast, Nashville
area, or West Coast.
Reply to:
Tore B. Nordahl, President
Rupert Neve, Inc.
Berkshire Industrial Park
Bethel, CT 06801
times.
R
www.americanradiohistory.com
p 59
"Dumping Iron"
A HIGH PERFORMANCE, LOW -COST
TRANSFORMERLESS
MICROPHONE PRE -AMP
PROJECT
by
Dave Baskind and Jon Sanserino
One of the longest standing necessary evils in mixing
consoles is the mike input transformer. As good as some are
made, they are still prone to all kinds of problems such as low
frequency distortion, transient distortion and sensitivity to
changes in source impedance, not to mention cost and size
(for a good one). But we can't do without them, because the
voltage gain they provide gives us a few precious extra dB of
signal -to -noise ratio, and they isolate the preamp from the
phantom power supplies used with condenser mikes.
However, if you can put up with a few more dB of noise,
especially on higher level tracks such as drums and
percussion where it can't be heard anyway, here is a low cost
solution that offers greatly improved performance in terms of
transient response and overall sound quality, and still allows
phantom powering to be used.
CIRCUIT DESCRIPTION
This transformerless mike preamp is an adaptation of an
instrumentation amp configuration. The front end network
of R1, R2 and C3 form an RF rejection (low pass) circuit with
the -3 dB point at 100 kHz and around 20 dB of rejection at
550 kHz (the bottom of the AM band). In areas with high RFI
problems, C3 can be doubled in value with a very slight audio
high end rolloff. D1 -D4, Cl, C2, R1 and R2 form a protection
circuit which protects the preamp from phantom power in
two ways: a) Cl and C2 block the DC voltage, and b) the
10 /63V
R10
3
Cl
R3
1N4001
10K
R12
3
32K
3.32K
2
V
31
C5
274
C7
100pí
100pí
R5
473
R8 3 32K
C4
1000/5V
INPUT
C3
=
R14
R6
0027µf
1K
i
GAIN ADJUST
(external)
o
150
100pf
C6
--1\/
R9
R7
V
2
R13
R11
3
32K
IC 2
C2
332K
03
R4
10K
R
I
3 32K
4.73
274
10,63V
150/10V
OUTPUT
_
R2
C9
D4
1W-01
TRANSFORMER LESS MICROPHONE PRE -AMP
Circuit Diagram
p 60
www.americanradiohistory.com
Studer A-800
When performance
more important
than price
is
... demanding recording engineers and studio managers
choose Studer. And when the requirement is multi- track, their choice is likely to be the new Studer A -800
with 14" reel
capability, 1/2 horsepower spooling motors and microprocessor controlled deck functions for the
smoothest, fastest tape
motion you've ever seen. It also includes new phase compensated amplifiers, a self- contained Autolocator
function and
numerous other convenience and quality features that make Studer's slightly higher purchase price less
costly in the long
run. For complete information on the Studer A- 800 -16 and A- 800 -24, please write to us.
Studer Revox America, Inc., 1819 Broadway, Nashville, Tennessee 37203 / (615) 329 -9576
fo, .,dditionel info.m,,hun
udc
Inc
o
3S
www.americanradiohistory.com
In Canada: Studer Revox Canada. Ltd
R
r
)) 6.?
IMPULSE ALIGNMENT OF
LOUDSPEAKERS AND MICROPHONES
PART TWO
by Gary Leo and Don Pearson
Part one of this article (R-e /p,
December, 1978) described a
method for observing the electrical polarity of speakers and
microphones with respect to a
known source. It included a
circuit and a test setup for making
these observations. It then went
on to show how to determine the
polarity between drivers in a
multiband speaker system and
how the frequency response
ABOUT ULTRA SOUND:
In addition to consulting and
design engineering, Ultra Sound
offers custom construction of
one -of-a -kind electronic projects
for sound reinforcement applications and rental of electronic
equipment.
A recent project was construction of the six -way stereo electronic crossover used during the
final shows at San Francisco's
Winterland Arena on December
31, 1978. It was designed for Bill
Graham's F.M. Productions as
specified by the Grateful Dead.
Ultra Sound is supplying a moni-
tor system to the Jefferson
Starship, presently rehearsing in
San Francisco.
Currently, Ultra Sound is in the
process of interfacing its custom
test equipment to its computer.
A partial list of Ultra Sound's
better -known clients include
WAH Sound, Sacramento, Cali-
fornia; Starfine Sound, Hard
Truckers Speakers, and The
Grateful Dead, all San Rafael,
California; and Hot Tuna, San
Francisco, California.
Figure
1.
Typical Impulse received
microphone. Horozontal scale
gornnet /Alv
=
at
200 micro -
would suffer if the drivers were
connected inproperly.
There are a couple of additions and
corrections to Part One of Impulse
Alignment. First, picture 4A had no
explanation. It shows the signals generated
by the circuit shown. The top trace is the
signal for the oscilloscope sync input, while
the bottom trace shows the signal after it
has gone through the bandpass filter (pulse
output). When using this circuit, adjust the
oscilloscope so that it is being triggered on
the negative edge of the pulse.
The circuit itself needs one minor
correction. The jumper connecting the
output of Op -Amp #2 to the wiper of the 5
kilohm potentiometer going to the pulse
output should be omitted. The final addition
is the calibrations on all the frequency
response measurement photos and they are
identical to those in Figure 3 of this article.
To begin this, the final article on impluse
alignment, a few points are in order. If your
oscilloscope does not have sufficient
sensitivity to view the microphone signal
directly, then a microphone preamplifier
should be used. It should be pointed out that
there is no general rule to follow with regard
to consistancy of phase polarity or whether
there should be alternating polarity between
crossover outputs. This is determined by
the taper and slope of the crossover in use.
There are several things that can be done
to improve a sound system. First, in a
testing situation, test the components and
make improvements, get rid of rattles and
vibrations. Then find the proper alignment
and mark the speaker locations relative to
each other so that the system can be
returned to this configuration every time it is
installed.
When the sound system is in use:
1 - Use an impulse test to verify that all of
the drivers are connected in their proper
Impulse response of badly
braced cabinet.
www.americanradiohistory.com
polarity, and optimize the alignment. This
may be omitted if nothing has changed since
the last use or alignment.
2 - Use pink noise and a real time
spectrum analyzer to adjust the system for
flat response by adjusting crossover output
levels and polarity. Then adjust the system
equalizer.
3 - The system is then adjusted to sound
good by the person mixing. This is most
critical and someone with proven experience will be able to please the greatest
number of people. It is not uncommon for a
sound system to be hired because of the
ability of the personnel operating it rather
than its hardware.
Part two will discuss the observation of
and problems associated with enclosure
resonances and some of the corrective
measures that can be taken using the same
basic test set -up. It will also demonstrate a
method for observing and adjusting the
arrival time of the signal from each of the
speakers in a multi-driver system.
Common Applications
Figure 1 depicts a typical waveform that
should be received at a microphone. Figure
2 shows the impulse response of a woofer in
a badly braced speaker cabinet. Note that
audible ringing is demonstrated.
Figure 3 is the frequency vs. amplitude
response of this woofer/enclosure combination. The peak in the frequency response at
4 kHz is a result of cabinet resonance. The
peak in the frequency response plot is due
to the resonances that the impulse
generated in the enclosure. Figure 3 shows
that the acoustic output of the cabinet
resonances can be almost as loud as the
signal coming from the speaker. The
crossover network can be partially
responsible for some of the ringing as
demonstrated in Figures 4 and 5. Figure 4 is
a three -pole Butterworth bandpass (18
dB. octave) filter (800 7 k) while Figure 5 is
-
Fgr.re
3
Frequency vs. Amplitude Re-
sponse
01
Figure
2.
FADEX GIVES YOU GREAT AUTOMATION
VCA-5M
GIVES
YOU
GREAT
The FADEX promise is very
straightforward. Easy retrofit of the
finest automation available, into
just about anybody's console.
Of course; console designers,
and users have varying psychologies
concerning the importance of certain audio performance parameters
to their "sound:' Some, for instance,
go for lots of headroom and gain
reserve. Others insist on wide
frequency response and very low
noise levels.
Some emphasize the importance of transient response,
T.I.M., twin tone I.M. and square
wave response. What separates
great consoles from the run of the
mill, obviously, is strict attention to
all audio parameters, rather than
just the designers favorites.
AUDIO
THE VCA-5M IS DESIGNED FOR GREAT CONSOLES!
It has to be. When you automate YOUR console with FADEX, our reputation for
excellence is on the line. The audio performance cannot be degraded, in any way, in any
installation. Our VCA-5M insures this sort of audio integrity, by offering superb performance in all known parameters of performance.
The real proof of performance, of course, lies in the ears of the user. Whenever we
FADEX a console, we ask "Well, how does it sound "? We always get the same monotonous answer: "It sounds just like it did before :'
allison research, inc.
2817 ERICA PL. P.O. BOX 40288
NASHVILLE, TENNESSEE 37204
for additional information circle no. 36
www.americanradiohistory.com
R-e /p 65
Figure 4. Impulse response of 18 dB /oct
Butterworth bandpass crossover 800-7 kHz.
Figure 5. Impulse response of 24 dB /oct
Chebyshev bandpass crossover 250-4 kHz.
Figure 6. Impulse response of the system
shown in Figure 2. after bracing.
four -pole Chebyshev (24 dB /octave) filter
gong type sounds (extended decay time),
then some corrective action must be taken.
The air pressure inside the cabinet normally
couples the speaker cone to the side walls.
As the speaker functions, the cabinet side
panels start to vibrate. These vibrations,
unlike acoustic resonances, can be different
from the passband frequencies generated
by the speaker. Acoustic resonances play a
part in the ringing problem, since a great
deal of power in the bass region will generate
sympathetic resonances in an improperly
constructed or braced cabinet. Horn -type
transducers also exhibit bell type sounds
which can be excited with a mallet or similar
object.
solving the enclosure ringing problem. Bear
in mind, though, that if a surface can move it
k).
250 Sweep the pulse output control of the
signal generator to different settings and
4
observe the received waveform. The
amount of ringing will vary with different
settings. The place where the waveform is
modulated the most is where the cabinet
resonances (ringing) is maximized. Leave
the generator set and feel the cabinet with
your hands. You should be able to feel the
actual panel vibrations. At this point an
accellerometer may be substituted for the
microphone and placed against the speaker
cabinet and walls. The test system is now
like a stethoscope for the speaker system.
Much can be inferred by striking the
cabinet in different places. You should hear
a dull thud. If you hear vibrations, rattles or
will resonate at certain frequencies.
a properly braced cabinet
usually reduces this problem significantly.
Ultra Sound has researched the ringing
problem with Hard Truckers Speakers, of
San Rafael, California, to improve enclosure
construction and bracing.
Some of the indications used are as
follows:
Any surface with a span greater than two
feet should be braced with a piece of wood
across the surface; cross bracing should
also connect opposing walls.
If there are any removable panels, they
should be screwed down around the
perimeter and also to cross bracing.
The thickness of the enclosure wall is
Constructing
Enclosure Construction and Bracing
There is no standard procedure for
The most versatile digital reverb ever made.
aIAnTAP MORN MAT IRrelreUTg1,
-1
KNrr.
WWI
epUALRATION
I/f COT
L/ CYT
TAPa
11
.
NOME*
22
1
URSA MAJOR
SPACE STATION
SST 282
PEAK LEVEL4a
for only $1995.
-a
Ursa Majors new SPACE STATION is a tree breakthrough in audio technology
digital reverb so versatile that it can create virtually any pattern of direct sound, early
reflections and reverberation, yet costs only a third of what you would pay for a
single-function reverb system. This easy -to-use unit will take your dry tracks and put
them into an endless variety of reverberant spaces, from tiny rooms to concert halls
to parking garages to sci -fi locales. And the SPACE STATION can do even more.
Multi -Tap Delay and built -in mixer give you totally new pure delay effects, while
feedback of a single tap provides simultaneous echo or resonance effects.
URSA MAJOR
Box 18
Belmont, MA 02178
USA (617) 489 -0303
R -e /p 6G
USA. Hollywood CA
AUDIO CONCEPTS
213 851 7172
USA Pekin Illinois
MILAM AUDIO
309 346 3161
KEY SPECS: Delay Mode: 80dB dynamic range.
7kHz. 256ms delay. 16 programs of
0.1% T(N
delay tines for 8 Audition Taps: ReWabMode: decay
time 0 to 3.5s. EQ .0: -10dB at 20 Hz and 7kHz. two
programs of revert taps: Echo Mode: delay time to
255ms. decay time 0 to I 3s. Mono In /Stereo Out.
LED Peak Level Indicator at 0.6. 15 and -30d8.
Manufactured in USA URSA MAJOR SPACE
STATION and Multi-Tap Delay are trademarks of
1
Ursa Ma or. Inc.
USA. new York NY
MARTIN AUDIO VIDEO
USA. Stamford CT
AUDIOTECHNIQUES
England. London
FELDON AUDIO
212 541 5900
203 359 2312
01
USA. San Rafael CA
BANANAS AT LARGE
USA. Strongsville OH
PI CORP
USA Cleveland TN
415 457 7600
216 238 0644
for additional information circle no. 37
www.americanradiohistory.com
580 4314
BROADCAST DISTRIB
615 472 8200
Canada, Toronto
J-MAR ELECTRONICS
416 421 9080
Japan. Tokyo
ELECTOR' CO.
(03) 950-6266
-
Figure 8. Arrival time difference
showing
both woofer and mid -range pulse. (Difference = 1.6 divisions
0.5 milliseconds /div
.8 ms or 10.8 inches)
Figure 7. Frequency response of the system
shown In Figure 3, after bracing.
mr^mm
%®iiii0®®®
Figure
9
Same as Figure 8 with speakers
adjusted for equal arrival time.
El111111111111111111111111111
111/11111111111i1111111111111
1/1111111111111111111111111111111
111111111M111E311
limmoulom
11111111111111111111111111111
0
50
100
200
1K
500
2K
5K
10K
20K
50K
cabinet, larger cabinets need thicker walls.
In all cases, high quality wood should be
used. If plywood is used, only accept wood
with plys made of solid laminations with no
gaps or filler. Filler, consisting of sawdust
and glue, is added to the gaps in cheap
plywood. The price of proper materials is
much more expensive than ordinary woods.
If there are any gaps in the layers, they will
start vibrating and breaking up the filler
between the plys causing buzzs and other
sounds. Hard Truckers only uses imported
14 -ply Finnish
birch three -quarter -inch
marine plywood in their construction and
bracing. All of their products make
extensive use of these materials and
techniques. High quality particle board may
be substituted, but it will not be as durable.
AUDIOARTS
r
.
AUOIOAIItS
d % "V
dr.
ENOINEEIMVO
+, ..
'
!'
An enclosure made with cheap plywood
may superficially resemble a high quality
cabinet, but after a short period of time it will
sound like a "rattle trap."
It is necessary to isolate the speaker from
the cabinet with a gasket. The gasket serves
two purposes; one is to insure an airtight
seal and the other is to provide some shock
,.
'
N.
/
rd
I
.
w
~
",
1
l.
11110.:
"!
..
,.
.
!
,
d
.,°°
\"
la
',
,,
ENGINEERING
.
y
Iui
A parametric equalizer without low, mid
and high band restrictions. The Audioarts Engineering Model 4200
is a four section stereo parametric equalizer; each section is a dual
range filter. CONSIDER an equalizer that can handle full +20 dBm
studio levels, regardless of equalization setting, but which also has a
low -noise preamp input to allow musical instruments to plug
directly into those same studio effects. The Audioarts Engineering
Model 4200 is a professional no compromise parametric equalization system.
--{t
In the 1920's, researchers at Bell Labs
...,.d.d..d,,..w.....«d.
1
CONSIDER THIS:
iAUDIOARTS
..
Background Information
Parametric Equalizer- Preamplifier
',
,
r
«,...
.
Model 4200
ar.sl swru.-nwwr
,
.
cabinet stuffing. Hotels and theaters usually
throw it away when they replace their
carpets. Coat the outer surfaces of the horn
with plastic resin or similar adhesive, and
press the padding into the adhesive and
allow it to harden. Make sure that all fittings
and connections are airtight and that any
mounting plates or adapters cannot rattle
against any other surface.
Figure 6 shows the impulse response of
the same system as depicted in Figure 2,
except that bracing and stuffing techniques
have been applied. Figure 7 is the frequency
response of the same system show in Figure
3 after bracing.
isolation.
The impulse response can be dampened
by changing the amount of stuffing inside
the cabinet. Increasing stuffing should stop
the high frequency reflections within the
enclosure from radiating out through the
port or through the cone material.
Ringing in horns can also be suppressed to
some degree. One approach to the problem
involves the utilization of some carpet
under -padding (waffled horse hair covered
ENGINEERING
NMI IMP
w th jute). This material also works well as
du.ù idnge tiller
SQL
l
it
EQ bypass switch for each se.
Master Equalization bypass swi;.
LED overload indicator
input gain control
line level input jack ( +20 dBm)
,II
..,1.^
untenl ple.unp input j.iLI.
output jack (a20 dBm into
load)
Iprocal equalization
inch rack mount
-' del 4200 (stereo) price: $599
., ,c: $335
"lrl -1100
qt SI
106
.
-:_ìa'"
2B6 DOWNS ROAD, BETHANY, CT. 06525 -203-393-0887
Designed and built in U.S.A.
for additional information circle no. 38
www.americanradiohistory.com
';-.l.i'..
.
SPEAKERS
HI
0
[FRQ:
AMP
HI
D
HI
MIKE
\
CROSSOVER
-MID
FREQ
MID
CHIAMP
Sync In
LOW
LOW-MID
MID
A
LFREQ
AMPJ
SCOPE
Vert In
LOW
CFREQ
WOOFER
AMP
MIKE
PREAMP
TEST SETUP
discovered that the arrival time of the sound
from speakers reproducing different
frequency components of the same signal
was important if high intelligibility was to be
maintained. Until recently, these concepts
have not been applied in the design of
commercially available systems. UREI
offers Time Aligned" Studio Monitors
(Time Aligned is a trademark of E. M. Long
and Associates). Other products are also
marketed under various tradenames.
Using the same impulse system setup
previously mentioned, it is possible to
observe the arrival of the impulse with
respect to time. For test purposes, consider
a four -way sound system containing an
---=- r
The DYNEX Noise Suppressor helps
get rid of electronic and environmental background noise without
sacrificing program clarity.
fir
filming or studio recording and
production.
Ofa1111115111MIU1
Choose low- frequency, high frequency or wideband noise
suppression. As legitimate program
energy in the suppressed band
don't have to live with noise. Find
out more about the DYNEX. Call or
write us today. Model 241,
You
increases, suppression is progressively reduced. The result is a cleaner DYNEX -$300.
sound for broadcasting, location
Inovonics Inc.
503 -B Vandell Way
Campbell, CA 95008
active crossover and a separate amplifier for
each speaker component (see diagram).
Preparation Before Testing
In the following discussion, it is important
that the crossover be included in the tests
for two reasons: first, the crossover
prevents out of range signals from damaging
the speakers and; second, the crossover
exhibits a frequency dependent time delay
which needs to be considered in the
measurements.
The test microphone should, within
reason, be closer to the sound system than
the first reflective surface and should be
pointed towards the system at approximately ear level. Since we are going to make high frequency measurements, the microphone
needs to be on -axis. If the speaker is on the
floor, place some carpet or other absorptive
material on the floor between the speaker
and the microphone to help minimize
reflections.
When a single broadband impulse is
injected into the system, it is divided into
four separate bandpass outputs by the
crossover, and then each output goes to a
separate amplifier and speaker (array). The
signal that was once a single impulse to the
input is now being reproduced by the four
separate speakers. If these signals do not
arrive at the listeners ears at the same time,
the coherence of the sound is reduced. The
results may be an auditory double image, a
smearing of the sound and a general
reduction in intelligibility. This is particularly
noticeable in the high frequencies because
the psychoacoustic properties of the ear are
much more sensitive to mid and high
frequencies.
The arrival time of the four signals from
the speakers is also controlled by the
physical location of each of those speakers.
Telephone
(408) 374-8300
for additional information circle no. 39
www.americanradiohistory.com
In the past, many people have lined up the
voice coils in a vertical plane. This is a step in
movement will alter the polar response.
Also, too much movement could put a
reflective surface in the path.
the right direction, but not a complete
solution. The problem of mis- alignment may
be observed fairly easily. If all of the
components are mounted in separate
enclosures, moving them forewords or
backwards relative to each other will help
bring the system into closer alignment.
decrease
The procedure for observing alignment is
similar to that used for checking polarity.
First, set the generator's output filter to a
low frequency setting and adjust the
oscilloscope so that the knee or breaking
point of the received impulse lines up with
one of the vertical lines on the scope
graticule (continue to trigger on the negative
edge of the waveform).
Most large portable reinforcement
Now slowly
mid -range
speaker's
amplitude. This impulse knee will then be
either to the right or left of the noted
graticule line. If it is to the left, then the
speaker is too close to the microphone and
needs to be moved back. Conversly, if it is to
the right then it needs to be moved closer.
Again move the generator to a higher
frequency and reposition the speaker
accordingly. Continue until all speakers
have been observed and adjusted. If you
move any speaker, then you may have to
adjust its level to compensate for the
increase or decrease in SPL since it is now
closer or farther from the microphone.
The aforementioned procedure can also
Testing Process
systems are built in a modular fashion, so
moving individual sections is not too
difficult. In the studio, however, the system
speakers are usually fixed into a particular
place so they are not easily moved.
It should be noted that the speakers
should not be tipped or tilted as this
and the
impulse will appear and increase in
move the generator's
frequency control to a higher setting. The
amplitude of the low frequency speaker will
.....-----
am.
°
e
Alf Ai
[el
.w_.
Unit
.IND
on MI
afla
III III
WM
UN
w au
Q',,;,::":--
e
r
._:..
..-r-r
18.0Z'
i
ilk
a
;
w tfa
>. Ia.
.,
01. IRO
a s.
.00
1111M.
fild
1114311
How's THIS for an encore?
Modern Recording celled our DL -I Delay "probably the best we have encountered"
a tough act to follow.* Now
after more than a year in development
DeltaLab introduces its encore - the
ACOUSTICOMPUTERD - a combination digital -delay and special-effects
processor designed for use both onstage and in the studio, providing well known functions (echo, doubling,
chorusing, vibrato, flanging, etc.) plus
new effects not available in any other
...
device.
Pre -reverb delay
with two independent
delay channels, variable from 0.25ms
to 152ms with LED display.
Delay up to 240ms in serial (mono)
mode.
Built in VCO with external control
input at rear.
Same no- compromise sound quality as
in our DL -1 Digital Delay: Full 20 -15
kHz bandwidth at all delay lengths
with 90 dB dynamic range.
Computer- synthesized acoustic space
with 16 selectable reverb programs
plus a new special effect in which the
ACOUSTICOMPUTER scans the 16
programs.
Two channels in and out. Built in reverb mixing and stereo imaging con-
Its impossible to describe in this space
everything the ACOUSTICOMPUTER
does; you'll have to experiment with it
yourself. By carefully minimizing the
number of separate controls and grouping them logically, we've made it easy
for non -engineers to operate the
ACOUSTICOMPUTER.
For further information call or write
Phil Markham at DeltaLab Research,
Inc., 25 Drum Hill Road, Chelmsford,
MA 01824 Tel. (617) 458 -2545.
*See
Modern
Recording "Hands On
Report," Sept. 1978.
trols.
Foot- switch controlled
DeltaLab
DeltaLab Research, Inc.
bypass.
27 Industrial Avenue, Chelmsford, Mass. 01824
Available at Quality Dealers
for additional information circle no. 40
www.americanradiohistory.com
R-e/p 69
Rugged high
performance
low cost mixers
For studio
or sound system
For remotes
For stage monitor
be used to calculate the mis- alignment. This
is accomplished by observing the relative
time interval between break points, then
convert the measured time delay to
distance. The time delay between the
drivers may be found by multiplying the
scope horizontal sweep switch setting in
milliseconds times the number of divisions
separating the impulse break points. Then,
since sound travels at 1130 ft/sec @ 70
degrees F, multiply 1130 times the time
interval in seconds. The result is the
distance of separation in feet.
D=CXT=1130X.001=11.13ft/ms
Where:
D = distance in feet
C = sound velocity (1130 ft /sec @ 70 °F)
T = time in seconds
The idea is to get all of the knees to line up
on or near the same vertical graticule line.
For further adjustment, tune the genera-
New Model 12X4A mixer
Over 500 INTERFACE ELECTRONICS mixers are
now in use in recording studios and sound systems
and wherever high performance at low cost is
needed. These mixers have been used in making
gold records and they are also specified by many
rock groups for road use because of their
ruggedness. reliability, flexibility, immunity to stray
equal to or better
fields. and high performance
than that of consoles costing many times more.
Mainframes are available for 8 to 32 inputs, and
modules can be ordered as needed.
-
SERIES 200:
SERIES 104:
SERIES 108:
submixes
SERIES 316:
two track stereo
four mono or stereo tracks or submixes
eight mono or stereo tracks or
sixteen tracks
Included are echo sends. cue sends (tour on the
104. 108 -316), solo. equahzers, pan pot. six step input gain adjust with two input pad positions. conductive plastic sliders, fully modular plug -in construction
using plug -in integrated circuits throughout. balanced
transformer inputs, output transformers optional.
New high slew rate IC's assure full output to 20 KHz.
MANY OPTIONS AND CONFIGURATIONS ALLOW
YOU TO HAVE IT JUST AS YOU WANT IT.
STAGE MONITOR mixer Model 104L makes eight
independent mixes. uses color coded knobs and
large lighted VU meters. optional headphone
monitor. intercom.
"American quality at Japanese prices."
INTERFACE
ELECTRONICS
3810 WESTHEIMER
HOUSTON, TEXAS 77027
(7131626 -1190
R
tor's output frequency upward, and then
downward while observing the received
waveform. As you follow this procedure you
should observe the familiar impulse. This
would be a good time to experiment with
different polarities between crossover
outputs. Reversing polarity will cause a
change in the amplitude and the wave
shape.
Listening Evaluations
Before you start your listening test be
using pink noise
sure to adjust the levels
on the
and a spectrum analyzer
- the
crossover outputs or on
power
amplifiers for your preferred listeners curve.
Use these controls as if they were
broadband equalizers, which they are.
Recently, many articles have been written
on the pro's and con's of impulse alignment.
Some have observed that there is no value
in making these adjustments and that there
will be no audible effect. The authors offer
the following experiment which allows the
reader to independetly judge for himself.
Using two identical speaker systems,
optimize the impulse alignment on only one
of them. While you are standing between
the two, have someone rattle a set of keys
into a microphone which is connected to
both systems. The authors have observed
that the adjusted side will retain its
intelligibililty as you walk towards it while the
sound from the non -adjusted side seems to
get lost shortly after moving off center.
Other effects the authors have observed
are that as you make the original sound
more coherent, the reverberation will
become less apparent. In the case of stage
monitors, the gain level may be reduced
slightly due to improve intelligibility, thus
effectively lowering the feedback threshold.
One of the worst mis- alignments measured was of a four-way system and totaled
e/p 70
www.americanradiohistory.com
approximately 14 feet. This was a portable
reinforcement system whose components
consisted of RCA type W horns, a closed
box array of 16 twelve -inch speakers,
compression drivers on radial and long throw horns, and ESS Heil Blue Ox Air Motion Transformers. The mis- alignment
was so great, that no corrective action could
be taken.
In some commercially -available speaker
systems, the alignment is achieved through
a combination of driver placement and
special delay networks added to the passive
crossover. On a multi -amp system, delay
would be required at each of the crossover
bands prior to the power amplifier. At the
present time, Ultra Sound has been unable
to locate a commercial delay which operates
satisfactorily while achieving the desired
alignment. Some of the available delays
tested could be used in the lower frequency
ranges, but none were acceptable in the
high frequency range where "birdies and
chirps" from the sampling processes were
objectionable. Some of the new generation
delays becoming available may resolve
these problems.
Another observation that may be made
from the impulse is the study of reflections.
To illustrate this effect, place an album
cover near the microphone and observe the
scope while changing the position of the
album cover. Now place some foam or other
absorptive material near the microphone,
between it and the nearest reflective
surface. This will reduce some of the
reflections. Thus, by manipulating the
that is, by covering
acoustic environment
or hanging things on the walls or other hard
you may
surfaces or by moving furniture
be able to minimize or control the
reflections arriving at the microphone.
Readers who do not have access to an
oscilloscope or circuit construction facilities
should still verify that all speakers sharing
the same signal are correctly connected
with respect to polarity. This applies to all
sound systems.
A commercial product is available for
determining polarity both electrically and
through the air from Sounder Electronics.
This device consists of a sending unit and a
receiver. The receiver has an internal
microphone and various input capabilities.
Indicator lights signify whether the received
pulse is positive or negative. For further
information, contact Sounder Electronics,
at 21 Madrona Street, Mill Valley, California
94941. An article showing a hand -held audio
phase detector was published in Audio,
January, 1978.
-
-
In Conclusion
Because every system is made up of
different combination of speakers, enclosures, crossover networks and power
amplifiers, it is difficult to establish a
standardized set of rules to follow with
which to "properly" adjust the impulse
BIBLIOGRAPHY:
response of a sound system. The authors'
suggestions here are offered as a relatively
simple means of observing speaker and
I The Application of Impulse Techniques
microphone connections and placement. to the Detection of Linear Distortion
Such studies are otherwise limited to those Alfred Schaumberger, JAES, September, 1971,
p. 664.
with access to complex and expensive
2
A Catalog of Frequency and Transient
equipment such as spectrum analyzers, Responses
D. Pries, JAES, December, 1977,
wave analyzers and Fourier analyzers.
p. 990.
3 Linear Distortion
Many subjects in this discussion were just
D. Pries,JAES,June,
briefly mentioned since the purpose of this 1976, p 346.
4
Acoustical Measurements by Time
article was to offer a basic measurement
Delay Spectrometry
Richard C. Heyser,
technique. It is hoped that interested JAES,
October 1967, p. 370.
readers will investigate the references listed
5 Loudspeaker Phase Characteristics and
in the bibliography that follows. Copies of Time Delay Distortion, Part One
Richard
these references are available at most public C. Heyser, JAES, January, 1969, p. 30; Part Two
April, 1969, p. 130 -137.
libraries.
6 -Determination of Loudspeaker Signal
The important information to be seen
Arrival Times, Part One Richard C. Heyser,
from the received waveform is the polarity JAES,
October, 1971, p. 734-743; Part Two
of the first arrival and its time relationship to November, 1971, p. 829 -834; Part Three
a similar first arrival from another speaker.
December, 1971, p. 902-905.
The ripples following the first impulse
7 The Response of Loudspeakers to Tone
V. Kaminsky, JAES, April, 1965, p.
sometimes can be seen to have a regular, Bursts
periodic structure. This may be an 119 -123.
8 Delay Effects in Loudspeakers
Paul
indication of resonances within the speaker Klipsch,
JAES, October, 1972, p. 634.
or cabinet. The waveform also contains
9
A Shuffleboard Experiment of Timesignals from reflections of other objects near Delay Effects in Loudspeakers
Gary
the speaker, microphone, or in the path Gilluum, JAES, May, 1978, p. 361.
10
Active and Passive Filters as
between them, so an exact interpretation is
difficult. This interpretation of the received Loudspeaker Crossover Networks Ashley
and A. L. Kaminsky, JAES, June, 1971, p. 494.
waveform could be accomplished with
11
On the Transient Response of Ideal
Fourier analysis to derive a frequency vs. Crossover Networks
J. R. Ashley, JAES,
amplitude plot, for example.
July 1962, p. 241.
12
Op -Amp Implimentation of Ideal
Crossover Networks -- J. R. Ashley and L. H.
-
Henne, JAES, January, 1971,
September, 1971,
-
14
-
-
-
Distortions Affect the Quality of Speech,
Trans. Audio, vol. AU -12,
1964).
17
Trans.
vol.
J. K. Hilliard, IEEE
p. 23 -25,
March-April,
P. Tappan, IEEE
AU -12, p.22 (March -April
1964).
18 Plain and Fancy Test Signals for Music
Reproduction Systems Ashley, Matson, and
-
Saponas, JAES, April, 1971, p. 294 -305.
19 Time Alignment in Loudspeakers
M. Long, Audio, August, 1977.
Crossover Network Design
20
-
Long, Audio, March, 1972,
21
-
-
-
-
E. M.
p. 34 -36.
Loudspeaker Damping
Nelson Pass,
-
-
reprinted JAES, November, 1978, p. 850 -855.
23 Audio Cyclopedia
Howard Tremaine,
Howard Sams & Company, 1959.
p. 52 -54.
22
Dividing Networks for Loudspeaker
Systems
John K. Hilliard and H. R. Kimball,
-
-
24
How to Build Speaker Enclosures
WILL TRAVEL!
"As a successful record producer, l am continually travelling to studios all over the world, recording
such people as David Bowie, Thin Lizzy and Mary Hopkin. l have to deal with a wide variety of
equipment in various studio settings; so in order to ensur that l have the best Compressor-Limiter
equipment to hand, l invariably pack a Vocal- Stresser in my suitcase
In my opinion, Audio & Design make the finest range of auxiliary processors available and their
equipment offers the producer/ engineer ultra flexibility in the creation of good music
&i-
r-
INMAN
...-
_I
r:
,y
-.
. .
..
A-
o
17,2
e Managing Director of
o
.,.
AI
_
t:.a
-
ID
A
ems = ,..
Good Earth Pro-
ductions and freelance produce, of many
`r
NIMwIIMnEe
Audio Ft Design Vocal Strasser uniquely combines a multi -ratio compressor with overall peak limiter and
low level noise expander/ gate with a parametric type equaliser in one package.
The combination provides most facilities necessary for improving and processing programme material whilst retaining maximum operational flexibility
The equaliser is simple to operate and can be switched before (pre), or after (post), the compressor -limiter, as
well as into the side -chain (s.c) of the compressor section for frequency modulation effects and changing spectral energy balance.
The
audio Et design recording
P.O, Box 23047, Honolulu 96822, Hawaii.
Tel: (808) 845 7226
www.americanradiohistory.com
-
Alexis Badmaeiff and Don Davis, Howard Sams
& Company, 1966.
Haue VOCAL STRESSER
says Tony Visconti*
E.
Audio, March, 1973,
-
-
Phase Distortion Audio,
Music and Sound Effects
--
-
-
J. R. Ashley,
Proc. IEEE, 1970, vol. 58, p. 959.
16
Notes on How Phase and Delay
-
-
Network with Maximally Flat Delay --
-
Frequency Dividing Networks
-
-
-
p. 674 -679.
W. E. Thompson, Wireless Engineer, October,
1952, p. 256 -263.
15
Butterworth Filters as Loudspeaker
-
-
p. 7 -11.
Electronic Crossover Network and
Their Contribution to Improve Loudspeaker
Transient Response
A. P. Smith, JAES,
13
-
-
hit records by illustrious pop stars, whose
own solo album "Viscontl's Inventory"
was released In mid October '77
Editor's Note: The following article was submitted for publication in R -e /p by Messrs. Rubens, Baskind and Caesar on behalf of a
product designed, manufactured and sold by their company.
R -e /p's publishing policy dictates that where sponsored, direct, competitive references and comparisons are made the
manufacturers of the products named should be offered the right of comment in the same issue.
In keeping with that policy, responses by David Blackmer, of dbx, and Paul Buff, of Alllson, follow the B d B /Aphex presentation.
VCA's
The Promise of Electronic Gain Control
by
Harvey Rubens
David Baskind
Marvin Caesar
In our fantasies as engineers, producers, and musicians
most of us have marvelled at what could be done with voltage
controlled amplifiers (VCAs).
In the studio, those six channels of carefully EQd, balanced
and panned voices, each with its own set of effect sends,
could be easily controlled with one group fader or mute
switch. In automated mixing, that elusive, almost "perfect"
mix, with only the last two bars of a guitar solo too loud, too
soft, or even in need of an EQ change, could be endlessly
repeated, changing only the errant track while retaining all
and all on first generation tape sothat
other mix dynamics
we could, theoretically, go directly from multi -track tape to
disk master, skipping the intermediate two -track (or quad)
generation losses.
In the field, in sound reinforcement applications, an entire
stage -full of mikes, effects and monitors could be balanced
and EQd via one coax cable or wireless system plus an
intercom merely by multiplexing all the necessary control
signals, thus eliminating expensive multi- conductor snakes.
It all seems so desirable. Yet, even though VCAs and
automation control systems have been available for several
years, the industry's response has been less than enthusiasinadequate performance by
tic for one major reason
previously available VCAs.
We human beings are possessed of an unusual set of audio
our ears. If we can't quantify
measurement equipment
distortion like a meter, we are quite capable of perceiving
changes that seem to defy detection using "standard"
if it
techniques. This leads to an obvious conclusion
measures good, but it sounds bad, we're measuring the
wrong things. Despite impressive manufacturers' specifications, signals passed through previously available VCAs have
been subjectively colored by them. What is worse, as we
shall see, is that the preceived coloration itself varies with (1)
attenuation setting, (2) signal frequency, and (3) thermal
conditions within the VCA, all of which make fixed compensation impossible. Finally, the noise performance of some
VCAs does not always match what is specified or even
measured with conventional techniques.
To better understand this discussion it will be helpful first
to examine the basic concepts of operation of VCAs offered to
-
-
-
Until recently, the only successful technique for achieving
high slew rate, wide dynamic range electronic gain control
has been the log -antilog technique typified by dbx and Allison
Research VCAs. These products differ from each other in
their actual realizations, but the basic computational
technique and the same general limitations apply to both.
The operation of these devices is based on the identity
log -'(log A
+
B)
=
(log -'B) x A,
where A = the audio input, and B = the control voltage.
Electronically the circuit computes the log of the audio input,
sums in the control voltage, and computes the antilog or
exponent of that sum, giving the desired dB /volt multiplication or division of the audio signal.
What does this mean to the non -math -oriented person
behind the console? First, electronic logging circuits can only
operate on signals of one polarity (positive or negative).
Therefore, to work on audio, the log -antilog VCA must
separate the positive and negative going portions of the
input, operate on them separately, then re- combine them
(see Figure 1). One obvious limitation to this class B mode of
operation is the precision with which one can match the
dynamic behavior of two separate circuits. This specific
problem is potentially greater in the dbx VCA than in the
Allison, since the former relies on the ability to match
discrete transistors of opposite polarity, while the latter uses
an all NPN monolithic array.
-.
-r
CON
OL TAG
OUT'S,
OUSE' BASIC FIGNAL FLOW
OF A LOO AST,LOG SCA
EGA
PO
G
AL
L,L.:.o:
the professional audio market.
IGURE I
BASIC SIGNAL
F
OF A LOG ANTILOG VCA
About the Authors:
Harvey Rubens and David Baskind have spent the
past two years developing a new, class A VCA which
is being manufactured by Baskind, Bissot and
Associates (B & B Audio) in Los Angeles, of which
Mr. Baskind is president.
Marvin Caesar is president of Aphex Systems,
Ltd., which handles worldwide marketing of the
VCA and other B & B products, as well as the Aphex
Aural Exciter.
OW
Inaccuracies are inherently greater in logging circuits at
higher frequencies and at high and low signal levels'''. Even
with well- matched transistors, the log -antilog behavior of
these circuits is only accurate over approximately a 40 dB
gain range with optimum performance centered at a specific,
trimmed operating point with respect to gain (usually near
unity) and input level (typically 0 dBv in the dbx and maximum
input in the Allison VCA- 5A /5M).
In the dbx 202 both THD and IM distortion vary widely over
www.americanradiohistory.com
Sonne people
buy us for
our fader
because ours is better than any you can buy elsewhere.
Ours has all the features you need, like smooth action,
accurate tracking, long life and low noise, plus a full 85 dB
attenuation. And ours is coffee proof. It's just one more
reason an Auditronics mixer is a better investment for
the long haul. To learn more, circle reader service number
or write to us for complete information.
It's coffee proof
0
au itronicf inc.
3750 Old Gerwell Road, Memphis, Tennessee 38118 / (901) 362 -1350
for additional information circle no. 43
www.americanradiohistory.com
R-e/p 73
Figuro 2
Figure 3
TM) vs ATTENUATION at 2klls
Input .20 dB,
Figure 4
ALLISON VCA.5A'5M
TMD vs Frequency for
Inputs of OdBv and 20dBv
INTERMODULATION DISTORTION IIMDI
vs ATTENUATION ISMPTE TEST)
Equivalent Input
15 dB.
=
-
0
IS
0
S.
24.
202
J
ALLISON VCA SA
ASS
Im
p22A
ps
(oJN
2632A
vC i
.........
20
}7FNuAlION
FIGURE 5a
io
50
20
100
566
260
.7 MI
Ms
.6EQUENCY
FIGURE 5b
attenuation as is shown in Figures 2 and 3, due mainly to
transistor mis- matches. On the other hand, Allison's all NPN
transistor array exhibits very stable performance over
attenuation. To accomplish this, Allison employs precision
rectifiers to separate the positive and negative portions of the
signal. The accuracy of such rectifiers depends on the open
loop gain of the Op -Amps used to realize the circuit (Allison
uses Texas Instruments TL074). A quick check with any IC
catalogue shows that, in any Op -Amp, open loop gain falls at
higher frequencies. Predictably, the Allison VCA exhibits
considerably higher crossover or notch distortion at higher
frequencies with respect to any given input level and at lower
input levels with respect to any given frequency (see figure
4). The scope photos of Figures 5A and 5B show that in the
Allison VCA the amplitude of the crossover notch, as a per
cent of the input signal, is substantially greater at 20Hzthan
a 2 kHz at the given input level (0 dBv). Photos 5B and 5C
show that this notch is greater at lower input levels at the
given frequency (20 kHz at 0 dBv and +20 dBv, respectively).
The distortion products generated by the above circuit
behavior include disturbance of the balance of overtones in
the signal and the generation of false overtones. These
changes are perceived in playback as changes in timbre,
presence, perspective and location. This can be likened to the
differences perceived with a change in mike placement
which changes overtone balance and phase relationships.
Note that in both of the log /antilog devices distortion actually
rises as the input level (Allison) or gain (dbx) is reduced. Since
our senses tell us that distortion usually rises with rising
signal, rising distortion with lower signal seems unnatural
and, therefore, subjectively more noticeable.
Thermal changes in transistor circuits may be caused by
environmental conditions or by the signal itself. Environmental changes are not usually critical in studio installations
since, typically, these changes are slow and affect a whole
system uniformly. Such is not the case with signal transients
which may quickly heat either side of a class B circuit,
thereby generating changes in transistor matching. What
this implies is that under such conditions, whether or not you
already like (or have accepted) a given sound through the
circuit, that sonic quality is itself subject to change with
transient heating when, for example, you un -mute a hot bass
FIGURE 5c
or drum track.
The last of the nasties in this rogues' gallery of VCA
behavior is noise performance. Typically, noise specifications are determined with no input signal present. What this
gives us is not necessarily a true signal -to -noise specification, since log -antilog VCAs are literally gated off when no
signal is present.
In a paper presented to the Audio Engineering Society
convention in March, 1978', the authors discussed methods
of analyzing dynamic noise behavior (i. e. actual noise levels
occurring in the presence of a signal). We called this
phenomenon "modulation noise" since it is noise modulated
in amplitude by the input signal. Modulation noise has been
shown to be psychoacoustically more detectable than similar
steady -state noise levels'. It is perceived as an undesirable
fuzziness in the sound, most notably on transient peaks. A
similar phenomenon has long been known in magnetic
recording.
F.pun M
MODULATION NOISE
0 as ATTENUATION
$g
B
a
g
/ ,.,- VCAsM
/
_ _____ ___
.......
....................................................................................
11
.6
o
EOU,aNn1 P.m input
Figure
9B
t532A
16
.20
,Oa,
GA
MODULATION NOISE Al
008 ATTENUATION
--
.....
.... ...............................................................................
... ........ ege Is32A
12
f0umeMn1
R-e/p 74
www.americanradiohistory.com
NM
IOput
I6FI
.16
.2D
FOr
BG
B
F °u
The
The
hilosoP
nt and
Themestt
test
te best
°nly 0
te
.
the bent
u
S
éntor's visa
the drat for
na
can
thatths BG and ne is A the
best P Absolu
quality kind of
mer to
or
an
higdé¡
high
P°
t
¡vers the
any
can buy road °ur er
h
m
Ot
W
SuP
GW
ers
grueling
50D
rks
a
cOntroi r0° a G -hig ost
upon
Sad
ers
t the
t ha madethene
isto rton, B
it b
to
Veae "sound th?Check
Paf
evoiutOrthY
dr,¡xer.
n9
renne
waed
there neat Part ellab¡UtY
r'ductor.
rho retie
every e° ñP
every
s
for
modular our
ehe
semen
quality
selected
cOm lei
soldered
panels,
Like ulously
s
d ba0k
or a
standards.
meticle
precision
and
P
irritatedchasse ales
resistor
exacting
tim óemai
steel
panels ä
built
m °d
are
heavy
es
front
¡ve
b
he
find
SUPm°¡ex c
Pd
t uct
d
s
t
ass
a
at vM ons °t a
d
nsn.
Ther
demands
BG
d isin lov
°r
the
avadablehe
at¡on,
eée ma9n
fro
test
s
and
eared
n b
in
in
ca
electrOnc n9
en9
d¡ffef
uP Pef noel
b
mto
óphistic ¡ants of an audeeethat
tth bac ns
te t0
re the
models with
e
Thy
ant
&
Ov
1O0
OfM
has
puy.
that
mon
y
company
ed
a
nit
re
Oud exPeásge n9 theehave recognized
the
innovation.
you
áßd aft ¡stcéáßd is
are things ePutati
e
rfro
a
d
relia
On
These enviable ¡nears
e
studio
builltt mord
e ¡ati stfvé bein qu e
imitated
ass
Bad
18
°
Of
are
you need
incredand oued h of c°n ed amps
Best.
tWo
s
are
agOth
tie These a d X50 pit m °re FoaThe
exPeri d
.stab Priced a ready, G°
industry
c
may
ouf pest, So
the
r
/Q
For
V
!
6
utjeyou're
enue.
S. Inc.
Systems,
Yukon
tHáWhorda Ornorne
Canada: de
I9fi53
en
N9P
e,
P
1A3
Dorval,
for additional information circle no. 44
www.americanradiohistory.com
R.e/p 75
Figure 7a Allison Modulation Noise
Figure 7b. dbx Modulation Noise
To their credit, Allison Research now at least partially
specifies modulation noise for their VCA- 5A /5M. However,
examination of their specification (92 dB below peak signal
level) only confirms our observation, since 92 dB below +20
dBv (typical peak signal level on ±15 volt supplies) yields a
noise level of -78 dBv -17 dB worsethan is specified for the
same circuit with input shorted at unity gain. This performance is roughly equal to our measured data at this one point
for the dbx VCA (and is much better than Allison's previous
model VCA -5
see graphs, Figures 4A and 4B, and scope
photos, Figures 5A and 5B). The scope photos are of
magnified distortion traces from the named VCAs throughout our harmonic distortion analyzer (Sound Technology
model 1710A) and clearly show noise gated around the zero crossings of the associated sine waves. Note also in the
Allison photo (which required less amplification to show the
noise) that the residual distortion trace exhibits the classical
B wave form. Those little peaks at the zero -crossings are
cross -over or notch distortion.
Now that you know what has been wrong with VCAs, you
might ask, "Who's doing something about it ?"
As noted at the head of this article, authors Baskind and
Rubens have developed a new VCA which is a radical
departure in design from log -antilog and other, earlier VCAs.
Its basic design is specifically addressed to overcoming the
basic performance limitations just discussed.
This new VCA is a true class A circuit employing a balanced
differential configuration which cancels most of its own
internal distortion products (see Figure 6). Also, residual
distortion (0.1% THD worst case at +20 dBv input) falls both
with lower input level and with attenuation to a typical .004%
THD at +10 dBv input with 10 dB attenuation.
The heart of the system is built into a custom monolithic IC
which gives it excellent transient thermal stability with
respect to both distortion and gain. The combination of
monolithic construction for good transistor matching and
differential configuration gives the circuit added immunity to
outside interference. Lastly, since the circuit is class A, there
can be no cross -over distortion, and modulation noise is
restricted to the inherent noise of a current flowing across an
impedance, which is characteristic of any active circuit (see
scope photo, Figure 7C).
Our research has given us new criteria useful in evaluating
not only VCAs but audio circuits in general. It is clear that we
can no longer be content to evaluate dynamic circuits under a
-
ti
ti
ó..
J`
FIGURE 8 BASIC SIGNAL FLOW
OF B &B VCA
Figure 7c: B &B Modulation Noise
few specified static conditions and expect to obtain
meaningful data. A happy result of this research is a truly
professional quality VCA whose performance is consistent
with the best of contemporary audio design. With this a
reality, the promise of electronic gain control can, at last, be
fulfilled.
O
BIBLIOGRAPHY
-
-
- Graeme, Jerald G.
Applications of Operational Amplifiers
Third Generation Techniques, McGraw-Hill Book Co., 1973, p.
1
-
94.
2 - Wong, Yu Jen and Ott, William E.
Function Circuits: Design
and Applications, McGraw -Hill Book Co., 1976, ch. 2.
3 - Baskind, David and Rubens, Harvey
Techniques for the
Realization and Application of Voltage Controlled Amplifiers and
Attenuators, Preprint No. 1378 presented at the 60th Convention of
the Audio Engineering Society, 1978.
4 - Minifie, Hixon and Williams
Normal Aspects of Speech,
Hearing and Language, Prentice -Hall, 1973, ch. 9.
-
-
response on behalf of
dbx VCA 202
David Blackmer
President, dbx, Inc.
It seems that Baskin & Rubens, in their eagerness to turn
the audio world upside -down, have used erroneous data and
questionable logic to arrive at their conclusion.
B & B shows a lack of understanding of the log /antilog
VCA when they claim that it is more difficult to match
transistors of opposite polarity (the dbx VCA) than an all NPN
array. In fact, the dbx VCA relies only on matching between
devices of the same polarity, not of opposite polarity. The use
of all NPN transistors in a log /antilog VCA requires greater
attention to matching between transistors and results in
increased circuit complexity. The superiority of the dbx
approach is demonstrated by the fact that the dbx VCA has
superior voltage offset vs. attenuation characteristics when
compared to either the Allison or the B & B VCA. This is of
particular importance when summing several channels
together as the offsets may add together and produce a
noticeable thump during rapid gain changes.
B & B's contention that log /antilog VCAs are only accurate
over a 40 dB gain range is also quite misleading. The
accuracy of the VCA is quite good over a range of 100 dB or
more at normal input levels. The distortion shown in Figures
2 and 3 was derived using very high input levels and is not
representative of the distortion encountered during normal
use. Perhaps a quick glance at our applications note might
have prevented this problem.
Another misleading statement is the one concerning
thermal distortion. There is no detectable thermal distortion
in log /antilog VCAs unless one uses input currents above
ma. If the VCA is used properly, the peak input currents are
five times lower than this value.
Now we come to the last of the imaginary nasties in our
rogues gallery, modulation noise. Certainly modulation
noise at significant levels, such as found in magnetic tape
recorders, is objectionable, but it is highly unlikely that
R-e/p 76
www.americanradiohistory.com
1
lexicon 224
DIGITAL REVERS
,1LAI.RClUM an
PROGRAM
1
IMMED SET
3
6
4
CALI SNIT
g
I"
FUNCTION
R
C
EGI STE
I'
REVERB-TIME
Model 224 reverberation system
hos the sound, the controls,
the compactness you've always wanted.
-
-
Lexicon
The remarkable
and remarkably compact
224 digital reverberation system gives you superb sound unmatched
electronic, digital or
by any other system available today
mechanical. You get smooth, natural decay without coloration.
"twang" or "boing ".
And you get unprecedented control over oll significant
reverberation parameters. Its industry's first reverb with o built -in control
memory that provides instant push -button recall of previously set effects.
Model 224 saves studio space and is fully portable. Its 51/2" x 8"
remote control console purs reverb control right at the producer's fingertips.
The system's high speed digital processor holds up to eight different
programs and requires only 7 inches of rack space.
Currently available programs include: concert hall programs with
stereo input and four outputs that create the space and depth of o live
performance with decay rimes of 0.6 seconds to 70 seconds; acoustic
chamber programs that provide sound equal to the best reverberation
chambers; plate programs that outperform the highest quality reverberation
plates or other mechanical devices with full control of all parameters
including pre -delay of up to 256 milliseconds.
Model 224. A major advance from Lexicon. Once you've heard it,
you'll never want to do another session without it.
-
Lexicon, Inc., 60 Turner Street, Waltham, MA 02154 (617) 891 -6790
www.americanradiohistory.com
R-e/p 77
modulation noise that is 80 dB below the peak signal is
psychoacoustically objectionable. Our tests, with a panel of
trained listeners, indicate that there is no audible signal
distortion or noise modulation effects when the VCA is
compared to a straight wire. The B & B VCA, which claims to
solve all of these "problems," has a few nasties of its own.
First, the unit is capable only of gain reduction as compared
to the dbx VCA which is easily capable of 30 dB of gain. If we
follow the B & B VCA with a gain of 20 dB, its output noise
becomes unacceptably high. This is certainly more of a
"problem" than the miniscule amounts of noise modulation
caused by the dbx VCA.
One of the important characteristics of a VCA is its voltage
control characteristic. The dbx VCA has a control characteristic that is linear in dB; that is, equal changes in control
voltage produce equal decibel changes in gain. This is very
important in automated consoles and makes it very easy to
program the gain of a channel and to produce natural sounding fades. The B & B VCA, however, has a control
characteristic which departs significantly from this linear
control curve making it difficult to accurately program the
gain of the VCA.
These problems seem to indicate that the B & B VCA will
find little use in the professional recording field. The charges
leveled at the dbx VCA are based on misleading data that is
not representative of actual -use conditions.
It is interesting to note that the B & B article devotes almost
a of its space to discrediting the dbx VCA and gives very little
information about the B & B VCA. When choosing a VCA for
professional use, it is necessary to examine all of the
specifications of the device, not just a narrow few as B & B
l l
has done.
dbx has introduced a new VCA called the 202C. This VCA
features all of the advantages of the 202 plus distortion
correction circuitry which will reduce distortion by a factor of
5 or more at the gain extremes. This VCA should satisfy the
most spec conscious console designer.
O
mislead the reader.
Since the bulk of the article serves as an attempt to
discredit my product, as well as that of a respected
competitor, find it necessary to devote a good deal of effort
to setting the facts straight. shall attempt to do this on the
most factual basis possible.
Before getting to the heavy stuff, allow me to make one
point of clarification. B & B made numerous remarks about a
device of our manufacture, specifically the "VCA -5." This
device was never put into full production, and served only as
an interim step to the production of our current VCA -5A and
VCA -5M. Last spring, under the guise of preparing a
"scientific paper" on the current state of VCA technology,
Mr. Rubens requested an evaluation sample of this device.
We gave it to him, explaining that the device had some bugs
and was to be superceded by a new series. At the time, Mr.
Rubens acknowledged that he would clarify the circumstances involved in any printed comment, explaining that the
device was not to be taken as typical of marketed product.
Since that time, have made several requests of B & B to
provide samples of their product, for my evaluation. Since I
have been unsuccessful in this attempt, have consequently
obtained a marketed sample, and data sheet, from a
customer here in Nashville, only yesterday.
I
I
I
I
-
B & B
I
with Class
response on behalf of
Allison VCA 5A /5M
by Paul Buff
President, Allison Research
I
I
shall do the best job can.
While the authors have presented some interesting views
on their new product, am of the opinion that they have been
a bit over -enthusiastic in comparing their device to VCAs of
previous manufacturers, particularly those offered by my
company and dbx, Inc.
If a manufacturer is to draw comparisons of this sort, it is of
paramount importance that he be factual, both with regard to
his competition as well as to his own product. It must be
remembered that the promise offered, by a publication such
as R -e /p, is to the reader, in the form of material which he
may use to better his understanding of the art. The privilege
extended to producers of new equipment, in the form of
editorial space, dictates that the authors present a true
picture of the subject matter presented, free of blatant
commercialism.
do not believe that B & B has adhered to these
fundamental rules of journalism. I found their material to
contain unfounded insinuations, errors, half truths and
omissions, of a magnitude, believe, sufficient to seriously
I
I
I
B.
Neither the dbx VCA, nor the Allison VCA are Class B
devices. They are Class AB devices, as are essentially all OpAmps, power amps and nearly all circuits to be found in any
audio console built in the last 15 years. In fact, the B & B data
sheet suggests the employment of no less than 6 Class AB
Op -Amps as external circuitry for support of their IC. think
with this information we can dismiss the insinuation that
Class A is great, and everything else stinks.
3 - B & B implies that, while dbx and Allison utilize
Log /Antilog techniques, B & B has developed a new and
revolutionary process to obtain multiplication. When you
have worked with bi -polar transistors as long as I, you begin
to realize that all methods of obtaining multiplication via bipolar transistors are the effect of the log /antilog transfer
function of the base -emitter junction of the transistors. For
instance, in the use of a transconductance multiplier type of
circuit, the mechanism which directs the diff -amp currents
I
wish to thank R -e /p magazine for the opportunity to
comment on the material submitted by Messrs. Rubens,
Baskind and Caesar. Unfortunately, have had but a few days
to review this material and put together my comments, but
I
I
-
THE HEAVY STUFF
ERRORS
claims to have developed a "New, Class A VCA."
The fact is that B & B has not created a VCA at all! In accepted
industry terminology, the statement "VCA" means Voltage
Controlled Amplifier, and denotes a device which is capable
of both gain and attenuation. The B & B device is not capable
of gain, but only attenuation. It is therefore a Voltage
Controlled Attenuator, VCATT. This category of device is in
no way a substitute for a true VCA, as shall point out later.
2 - B & B claims that both the dbx and Allison VCAs are
"Class B" devices. They then go on to extoll the virtues of
Class A, while claiming all sorts of bad nasties associated
1
is hidden away from obvious view, but is indeed the
log /antilog base -emitter characteristic, complete with all its
small non -linearities. While these non -linearities may show
up in different parameters, from one design to the next, they
are always there.
4 - B & B suggests that the log /anti log characteristics are
"only accurate over approximately a 40 dB gain range,"
inferring that Allison and dbx VCAs are accurate only over
this range. They further indicate that these VCAs exhibit
optimum performance only at a specific trimmed operating
point near unity gain. B & B continues by stating that
"transistor mismatches cause rising THD and IMD as the
VCAs are attenuated away from this point."
R-e/p 78
www.americanradiohistory.com
- continued
on page 80
'Mex Series 300 Duplicating System is versatile and
expandable and fits most duplicating requirements.
mismismi
k
v atog
r"rr;-:
Building Block
System: A modest
A
capital investment gets you
started whether in
cassette-toc as s ett e, ree
l-t ocassette, reel -to -reel, in two or four
channels. Start with a basic unit and
later add modules to suite your growing
requirement.
Now Long Life Heads at No Extra Cost:
Cassette slaves with new long life
heads last 10 times longer than conventional heads, reducing downtime and
replacement cost.
also has available desk top
cassette copiers.
Telex
r
R-e/p 1/79
,
Mail To TELEX A -V DEPT.
9600 Aldrich Ave. So.
Minneapolis, MN 55420
Modular Electronics: Individual plug -in
modular electronics permit fast easy
service and minimum downtime. Since
the system is made in the U.S.A., parts
and service are readily available,
through a coast-to -coast dealer network.
Yes. I'd like to know more about
the Series 300 high -speed tape
duplicating systems.
Name
Title
Organization
Address
TELEX
City
COMMUNICATIONS. IHC
9600 Aldrich Ave. So.. Minneapolis.
MN 55420 U S A. EUROPE. 22 rue de
la Legion-d'Honneur. 93200 St Denis.
France. CANADA Telak Electronics.
Ltd Scarborough, Ontario
.
-__.
State
Zip
Telephone
Best time to contact
L
for additional information circle no. 46
www.americanradiohistory.com
J
Re/p 79
It is obvious to me that the authors have only a partial
knowledge of the behavior of log /antilog multiplers
enough to sound like experts, but not enough to explain their
true behavior. Particularly, as it applies to the differences
between the dbx and Allison designs.
The Allison VCA -5A and M are, indeed, extremely
accurate over a gain range of 140 to 160 dB. Gibbons and
Horn showed that 9 decades (180 dB) of accurate log /ant ilog
function can be obtained, using bi -polar transistors, in the
early 6Os. B & B seems confused by, or unaware of, the
distinction between the actual conversion of audio to log
form, and the logarithmic response of the control circuit, as it
applies to the dbx and Allison VCAs.
If one were to attempt to configure either of these VCA
-
designs in "Class B" fashion (as B & B erroneously
suggested), it would be necessary to perform the full
log /antilog conversion on the entire magnitude spectrum of
the audio signal. This approach is impractical since, at very
low audio levels, the logging current would become
exceedingly small, resulting in severe limitations to
bandwidth and other parameters.
Consequently, both dbx and Allison employ "Class AB," in
two differing structures. This approach removes the
necessity of logging the entire audio level spectrum, via the
inclusion of a bias current. Thus, the log amps only actually
operate over about a 40 dB current range, maintaining
excellent bandwidth and extremely low errors.
The logging restrictions which apply to the circuits which
pass the audio itself, however, are not nearly as stringent in
their application to the logarithmic transfer function of
control volts vs. gain. Here, a full 160 dB of gain control range
is easily obtainable, with a typical error from true log
conformity of around 1% (1 dB per 100 dB).
Furthermore, the rising distortion vs. attenuation curve
exhibited by the dbx VCA is not caused by "Transistor
mismatch." This characteristic is caused by a very predictable parameter of the log /antilog transistors, namely the
error from true log conformity introduced by the finite
resistance associated in the base /emitter junction. At the
operating gain where the log currents exactly equal the
antilog currents, the two error signals oppose each other,
and cancel the effect. At any other gain point, the two errors
are unequal, and manifest themselves as distortion products
which are directly proportional to the signal level. The effect
is entirely predictable, and has nothing to do with "Transistor mismatch," as B & B suggests. Three methods of dealing
with the error are:
A. Reduce the operating current to the point where
the distortion products are acceptable.
B. Increase the geometry of the log /antilog transistors to minimize the resistances which cause the error.
C. Introduce an error cancelling signal which
removes the effect.
In the dbx design, methods A & B are used. The discrete
transistor approach allows the employment of large
geometry transistors to minimize the base /emitter resistances.
As far as the choice of operating currents, in the dbx
design, this is left up to the customer. The choice of signal
About the Author:
Paul C. Buff, in his capacity as president and
design engineer of Allison Research, Inc., Nashville,
Tennessee, has been involved in the art of voltage
control of audio equipment since 1970. Allison
Research is a recognized pioneer in the field of
automated mixing techniques and hardware.
current is, of necessity, a trade -off between noise and
distortion. Fortunately, the mechanics of the situation are
favorable, since a 6 dB reduction of distortion products may
be obtained at a cost of only 3 dB noise increase. (Or 12 dB for
6 dB, etc.)
It is unfortunate
that B & B, in an overzealous attempt to
make dbx look bad, chose to depict the distortion curve
realized at very high signal currents, and conveniently chose
to imply that this was typical at all operating currents.
As for the Allison VCA -5A and M, we chose to use the
approach outlined in "C" above, namely that of removing the
effect entirely, via the introduction of an error cancelling
signal. This technique is a very important attribute of our
design, since it allows the use of small geometry monolithic
transistors (with their inherent close match and thermal
stability), while effectively removing the restraints of noise
vs. signal current vs. distortion.
The effectiveness of this proprietary technique can be
seen by referring to the noise and distortion curves for the
VCA -5A and M.
5 - B & B makes a disaster of attempting to explain the
VCA -5A and M circuitry, and cites references which have
absolutely no bearing on the circuit used.
The Allison VCA -5A and M do not employ "Precision
rectifiers" in splitting the signal. The type of circuit to which
B & B makes reference is an active rectifier which, indeed,
provides usable precision only to around 3 kHz.
The polarity divider employed in our VCA design is a
proprietary passive design which provides extreme accuracy
to beyond 1 MHz. None of the aspects of this circuitry are to
be found in reference books, but, rather, only in the claims of
our pending U.S. Patent.
6 - B & B claims that the VCA -5A and M exhibit optimum
performance "Only at a trimmed operating gain and input
level." call the readers attention to the measured
performance graphs of my Figures 13 through 18, wherein
the performance of the worst of two VCA -5Ms (randomly
selected from production), is plotted against that of a B & B
VCATT. As can be seen, the Allison VCAs exhibit superior
performance at essentially all combinations of level and
attenuation, or gain.
7 - B & B sets themselves up as experts on psychoacoustics, and make claims which have no basis in fact, and which
are in direct conflict with all known principles regarding the
perceptive qualities of the human ear. These statements are
no more than blatent libel, and only serve to prove that B & B
has not actually listened to the devices in question. Because
of the immense magnitude of presenting a meaningful
discussion on the perceptability of various distortions
produced by electronic equipment, have committed a full
length article on my views of this subject, to appear in the
next issue of R -e /p magazine.
Suffice it to say, for the moment, that the Allison VCA -5A
and M offer excellent performance on all parameters known
to induce coloration or perceptable difference between input
and output signals. These parameters include the full
spectrum of THD, SMPTE IMD, Twin Tone IntermodulaI
I
tion Distortion, TIM, Slew Induced Distortion, Square
Wave Response, Phase Response, Frequency Response
and Modulation Noise.
The proof of the pudding, of course, is in the listening. We
communicate with our customers and solicit their comments
regularly. How come they don't hear all that garbage that B &
B claims they ought to? should be happy to submit a list of
our VCA customers to anyone who would like to hear their
comments.
In commenting on the "crossover glitch" portrayed by B &
B in their scope photos,
must state that:
I
I
continued on page 82
R-e/p 80
www.americanradiohistory.com
Studio quality microphones
that don't need
a studio t.. urvive.
The CS15P
condenser
cardioid
microphone is equally
at home in a recording environ
broadcast studio. When hand -held
puts sex appeal in a voice with its ba
boosting proximity effect. With shaped
high- frequency response and its ability
to handle high sound
pressure levels (140dB
with 1 THD at 1kHz), the
CS15P is ideal for close -up
vocal or solo instrument miking applications.
When boom mounted, the
CS15P has better gain- beforefeedback and a better signal to -noise ratio than most shotguns. Its phantom powered
and its rugged.
P
condenser omni
equency response to the very
bility, 20 to 20,000 Hz. Unlike
mini's:. the CO15P maintains
rectional polar pattern at the
very highest frequencies.
Perfect for the distant miking
of an entire orchestra as well
as up close on individual instruments. And like the CS15P, it's
phantom powered and its rugged.
The Electro-Voice warranty
Electro -Voice backs up these two
microphones with the only unconditional warranty in the business:
for two years we will replace or
repair your CS15P or CO15P microphone, when returned to Electro -Voice
for service, at no charge - no matter
what caused the damage!
We can do this because we build these
microphones to meet our standards for
performance, ruggedness and durability.
We accept nothing less, and if you're
professional, buying a professional
quality microphone, you shouldn't either.
a
u
UL
I
System C
1
J
[.74;
Electrol/oicé
a
quiton company
600 Cecil Street. Buchanan. Michigan 49107
for additional information circle no. 47
www.americanradiohistory.com
R-e /p 81
A - These photos are of the residual components of the
audio, after filtering out the original signal, and are highly
magnified.
B - The actual energy contained in the glitches is in the
vicinity of 60 dB below the signal, and is in the frequency
spectrum of 100 kHz to 1 MHz.
My Figure 21 shows the distributed energy of the
residuals, as obtained by spectrum analysis to 100 kHz,
while my Figure 22 shows the appearance of the residuals
when the THD analysis is performed on a Sound Technology
using the 80 kHz signal bandpass filter.
If anyone at B & B can hear these effects, or any of their
dogs, for that matter, would suggest a career with the CIA or
NASA.
understand that they both have openings for
superhumans.
8 - B & B implies that VCAs of the type made by Allison and
dbx are subject to thermally induced transient distortions,
which are produced by doing such things as "un- muting a
hot track." believe, if given the task, could design a device
with such poor thermal engineering as to cause such a
problem. This, however, does not mean that have designed
such a creature. The monolithic transistor array used in the
Allison VCAs, together with symetrically balanced circuitry
assures freedom from such effects. This may be readily
verified by lab measurement, or by critical listening tests. It
I
I
I
I
I
be noted that our data sheet contains a
specification for dynamic temperature sensitivity.
9 - B & B makes a very big deal about modulation noise,
claims to have discovered the phenomenon, and shows
irrelevant scope photos on the subject.
Firstly, call your attention to the un- retouched scope
photo, as taken from the VCA -5A and M spec sheet. (Figure
1) Note the absence of visible (or audible) modulation noise
amidst the distortion residuals (.03 %). The reason the noise
is neither visible, nor audible is the fact that it is 22 dB below
the distortion residuals, and 92 dB below the signal itself.
further call your attention to the fact that this spec sheet (and
photo) were in B & B's hands at the time of their writing, yet
they chose to use the irrelevant photo of the VCA they
borrowed for "scientific purposes," without explaining its
origin.
should also
I
modulation noise accompanies a signal at a level beyond 70
dB below the signal level, the ear is unable to perceive the
noise, through masking effects, in the same manner as it is
unable to perceive distortion products of similar magnitude.
(.03 %)
The modulation noise produced by the VCA -5A and M is
92 dB (.0025 %) below the signal level, and is totally
inaudible.
B & B made comments regarding the perceivability of
modulation noise on transient material, and think this
statement needs some clarification. In some equipment,
such as typified by tape noise reduction chains, a transient
signal can trigger a noise signal which persists considerably
beyond the removal of the transient. This type of modulation
noise, indeed, becomes more detectable on transient
material than on steady -state material. However, there is no
basis of comparing this type of gated modulation noise to the
type produced by a VCA. Figure 2 shows examples of the two
types of modulation noise. The noise shown in Figure 2B has
been triggered by the signal transient, and lingers long after
the signal. The human ear perceives the very short duration
signal transient as having a very low energy content, due to
its short duration. The actual electrical energy level of the
transient, however, is considerable. Thus, the expander
portion of the noise reduction system has raised its gain, as
dictated by the high signal level. Since the dynamics of a
noise reduction system do not allow it to actually follow the
signal waveform, there is a delay, or release time involved in
recovering from a burst of signal energy. During the time,
after the removal of the signal transient, that the expander
remains at high gain, the tape noise is passed through at a
higher than normal level. Since there is no signal present to
mask the noise during this time, the noise, following signal
removal, is perceivable as a swishing or pumping sound.
I
SIGNAL TRANSIENT
0 dBv peak
I
TRIGGERED NOISE
-50dBv peak
MODULATION NOISE
-92 dBv peak
t
-aS
FIGURE
2
DEPICTION OF TRIGGERED MODULATION
NOISE vs VCA MODULATION NOISE
10kHz THD, byproducts <.03% +20dBv in Unity Gain
Figure 1
VCA -5M Residual Distortion Products Showing
Absence of Noise Modulation
While it is widely known that modulation noise can be
perceived as causing fuzziness, it comes down to a matter of
severity, in the same manner as do other parameters such as
THD, IMD, TIM, and etc. In tape machines, we are accustomed to modulation noise in the broad range of 30 to 50 dB
below signal level. (.3% to 3 %) It is not difficult to perceive a
disturbance signal of this magnitude. However, when a
R-e/p 82
In the VCA type noise modulation of Figure 2A, the noise is
neither triggered, nor does it linger. It is actually impressed
on the signal, at a level some 20 to 30 dB below the point of
perceivability. If the signal is transient, so is the noise. Thus
the 92 dB separation between signal and noise remains
effective and unchanged, regardless of the nature of signal
transients. Critical listening tests will confirm both cases.
-
THE REAL HEAVY STUFF
OMISSIONS
This section will deal with the important parameters
which B & B chose to omit, in reference to the various VCAs
available. Beside other less important parameters, the
biggies are: Gain Control Range, Control Signal Rejection
and the Implementation of Practical Circuits.
continued on page 84
www.americanradiohistory.com
-
The full-function
one-inch eight-track.
Otai-i MX7800.
The sophisticated machine sets the
new standard for one -inch eight
track master recording. It comes
with the latest electronics and every
function indispensable for heavy duty applications. Designed with
ruggedness and extra easy operation
in mind.
-
DC -servo 30/15 ips direct drive with
minimum wow /flutter and ± 12%
pitch control for variable speed playback. Constant- tension reel servo
with motion -sensing control logic
plus new dynamic braking system for
minimized tape shock and tighter
timing. Built -in 700Hz /5kHz test
oscillator for alignment convenience.
And it features perfect remote controllability. Full remote selective
synchronous reproduce on all eight
tracks. Automatic monitor switching
to the pre -set mode record, reproduce or synchronous. Remote coarse/
fine two -stage pitch control for the
-
± 12% range. Precise remote
timing with return -to -zero memory
for mix -down convenience. Remote
position locator with automatic click free punch -in /punch -out function.
full
Easy -to- access transport and plug -in
electronics for improved serviceability, and thorough heavy -duty design
for utmost reliability.
If you've been looking for a full -function one -inch eight -track machine,
this is it. For the full story about the
ingeniously designed masterpiece,
contact your nearest Otani dealer.
U.S.A: Otan Corporation,
981 Industrlcal Road. San Carlos. California 94070.
Phone: (415) 593 -1648
Japan: Otan Electric Co.. Ltd..
4-29-18 Miriam! Ogikubo. Suginami -ku, Tokyo 167.
Phone: (03) 333.9631
for additional information circle no. 48
www.americanradiohistory.com
R-e/p 83
It can be readily seen that a soft passage can be brought up
to as much as 30 dB of gain by operating the associated
channel and group faders to their maximum.
Since today's quieter recording mediums allow placing a
greater dynamic range on tape, this sort of gain reserve is
necessary in structuring a flexible mixing console. In Figure
3, show the typical configuration of such a system, using
the VCA -5M. Figure 4 shows the implementation of a circuit
having a similar gain reserve, using the B & B device.
As stated previously, the B & B device is not a VCA, but a
Voltage Controlled Attenuator. The obvious conclusion one
might draw is: "Who cares? Gain or loss is relative. We'll
follow it with an.Op -Amp and it will effectively become a
VCA." In fact this is what B & B suggests in their spec sheet,
as they show up to 15 dB of gain being obtainable in the OpAmp which follows the attenuator element. Unfortunately,
this does not make the device a VCA, it simply becomes a
VCATT followed by gain.
The act of following the device with gain simply raise all
components of its output by the amount of gain inserted.
These components, of course, include noise, modulation
noise, power supply noise (not specified), control signal
crosstalk, etc. Additionally, the maximum attenuation is
reduced by the amount of inserted gain. Putting gain before
the VCATT element is no better, since it only serves to reduce
its input overload point.
As for control signal rejection, allow me to quote from the
B & B data sheet. "DC shift vs. attenuation = less than 5 mv."
(No test conditions given.)
Now let us look at the performance of the VCA -5A and M,
for the related parameters, as taken from our data sheet:
Gain Control Range =
kHz
+35 dB to -120 dB (155 dB) @
+35 dB to -105 dB (140 dB) @ 10 kHz
I
I
+35816-to -12036
AUDIO OUT
AUDIO
(To sumo% N(, Boss)
N
FIGURE 3
CON SOLE CON FI6U2. V
JF ALUJON VCA -5M
31ANUEL
FADER
<
GROUP
FADER
MWTER
AUTOMAT IO IJ
MUTE /JODUaa
ETC,
=
1 mv output level shift
with gain modulated from -100 dB to
Less than
+20 dB @
Output Noise:
(20
-
20 kHz)
1
-4
r
kHz (No input)
=
-;sag
35 To
-100á6
O To
-96 dBv @ Max. Attenuation
-89 dBv @ Unity Gain
-73 dBv @ 20 dB Gain
Power Supply Rejection
(Referred to input)
srs3
GRIUaD
1
Control Circuit Rejection
I
I
AUDIO OUT
54 dB @ 120 Hz
46 dB @ 1 kHz
is 0 dB to -103 dB @
(The stated gain control range for B & B
low frequencies; 0 dB to -99 dB @ 10 kHz.)
AUDIO
I
STO SUMMING.')
N
FIGURE
FAOEREI
ókß
GRO U P
PRACTICAL IMPLEMENTATION
As a model for the utilization of VCAs in audio consoles,
will typify the configuration, in basic form, as employed in
the following equipment:
The Allison Fadex System
The Harrison Console
The API Console
The Allison Designed Sphere Console Automation
The Allison Designed Auditronics Console Automation
The Allison Designed Trident Console Automation
All of the above named equipment employs either dbx or
Allison VCAs, in either conventional or automated formats.
These systems gain enormous benefit from the ability of the
VCAs, located in each input module, to be gain controlled by
the sum of control voltages produced by the channel faders,
the group faders, VCA Grand master, mute and solo systems,
compress /expand detectors and, of course, automation. The
configuration is, contrary to B & B's comments, very
enthusiastically received, and is rapidly becoming an
Industry Standard configuration.
As one might guess, the VCAs employed must have a very
wide gain control range, in order to accept the numerous
controlling sources, and must have a precise log (dB vs.
Volts) control response, for accurate grouping.
In typical service, the channel faders will be nominally
placed around unity VCA gain, but will have reserve gain (top
of fader) of around 15 dB. The group masters have a similar
gain structure, that is to say they can direct an additional
gain of up to 15 dB to the VCAs which are assigned to the
group fader. The VCA Grand master will have a similar
structure.
I
FADER
4-
CONSOLE
CoNFIGU4ATION
E.T.A NO
FOR 51 ICLAR GAI t.1
M AtTER
To WI AT tOe.)
I JO(-O
ÉTGE
Beginning to get the picture? Yes, am being cruel to B & B,
but these are real configurations of modern consoles being
mass produced. In short, this is the type of equipment which
B & B proposes to have a miracle fix for. Remember their
closing words: "A happy result of this research is a truly
professional quality VCA whose performance is consistent
with the best of contemporary audio design. With this reality,
the promise of electronic gain control can, at last, be
I
fulfilled."
Let us proceed to Table
that promise!
to see just how well they
1
TABLE
1
Figure 3
(ALLISON VCA-551)
PARAMETER
fulfill
Ftnure 4
(B&B VCATT)
CHANNEL GAIN RANGE
3508
SHUT -OFF (Max Attenuation)
-120dB 0 1kHZ
-10548 010kHZ
-68d5 0 lkHZ
-6448 010kHZ
-98dBv
-6508v
-89dBv
-64á8v
-73dBv
-6148v
-7448v
-4948v
-6148v
-5048v
-70á8v
-48dBv
-8248v
-4748v
4300mv
(1048 below signal)
41.5 volts
(548 above signal)
channel)
OUTPUT NOISE AT SHUT -OFF
OUTPUT NOISE AT NOMINAL MIX POSITION
(Per channel)
(1
OUTPUT NOISE AT
20dB
CHAN.
GAIN
OUTPUT NOISE 0 NOMINAL MIX POSITION
(Based on 32 mixed channels)
OUTPUT NOISE 0 MAE ATTENUATION
(32 channel console)
NOMINAL
CONSOLE NOISE ./31 FADERS
1 0 20dB GAIN
CONSOLE NOISE /32 FADERS 0 1548 GAIN
CONTROL SIGNAL FEEDTHROUGH 0 1 FADER
CHANGE FROM -100 to *2048 GAIN
CONTROL SIGNAL FEEDTHROUOH UPON
ADJUSTING VCA GRAND MASTER FROM
-100 to .2048 GAIN
R-e/p84
www.americanradiohistory.com
to -120dB
lev
(6098 below signal)
45mv
(4548 belo. signal)
.35dB to -8548
DISTORTION 101
Harmonic and intermodulation distortions have negative effects on more than
just your ears. Ever sit down at a synthesizer for an hour and after the third
ring modulation of half a dozen frequency modulated square waves (stirred, not
shaken), you're searching for your roll
of Turns? This peptic phenomenon isn't
caused by lack of musical ability (hopefully), but rather the richness of all those
bizarrely intermodulated, triangularly
squared, complex waveforms, harmonically grating on your stomach. Bad sneakers!
Transient distortion is another indiges-
If
Input -
And Output =
150KHZ
r\
tion which might put an annoying edge
on the vocal (that 40db of good old padding won't cure) or make an excellent
cymbal sound as if it might be an incarnation of a garbage can lid.
EXAMPLE: Good transient response,
adequate slew rate and low distortion
products, all work to retain the luster
of a fine piano, allowing it to function
or "work" in a mix...compatability, if
you will... (won't you? -humor me, OK!)
Anyway; note the illustrations, memorize the text, and there will be a quiz
on Monday.
(Poor Slew)
But Not
(Happy)
Then
150KHZ
150KHZ
Producer
(Transient Problems)
(Low End Problems)
(Ill)
But!
If
Input =
And Output
2KHZ
Or
=
2KHZ
Then
2KHZ
41)
Producer
TRANSAMPTMLZ
transformerless
preamp respectable quality!
mic
of
Available in plug in (15 pin edge connector) or as a retrofit for MCI consoles.
A product of the
A
Valley People, Inc.
P.
O. Box 40306/2821 Erica Place /Nashville, Tennessee 37204/615- 383 -4737
for additional information circle no. 49
www.americanradiohistory.com
R-e /p 85
FURTHER ANALYSIS AND TESTS
Thanks to a studio operator here in Nashville, was able to
procure (just yesterday) a B & B #1537A. The unit came
mounted on a board provided for retro -fit into an MCI 528
console. In reading the B & B literature, noted the claim that
this module would "greatly upgrade the performance," by
simply plugging in the new module.
Since had recently done a very exacting study of the
signal and noise parameters of this console, decided to find
out what improvement, if any, could be derived by substituting the B & B module for the existing dbx #202 VCA. The
original basic console structure, to the best of my knowledge
as based on MCI schematics, is as shown in my Figure 5.
I
-
Figure 6: IMO- vs Input Signal at Worst Case Fader Position for
=_Circuits of Figures 5, 10, 11 & 12
--
-
-
-
I
I
gai_"
-
-
-
IMP.
I
-
- --___...
1
--
--i°
--
r
- - --
.25
-
AY
-
tit.
-_
D%
1.04a
.y
si..
-
-3%
-
OUT
*[T]
=
S1M1AL
t0
CCtJT OL VOLTAGE -lode./VOLT
-.6v To +10v ( +.6v IJomiNAII
_
;
-- Figure
at Worst
7: 1 kHz THD vs Input Signal
Case Fader Position for
_Circuits of Figures 6, 10, 11 & 12
rIGLIRE
STANDARD MCI
528
-
VCA CONFIGURATION
At the normal operating point of the fader (control voltage =
+.6 V) the nominal -11 dBv dBv audio input level is
attenuated 6 dB within the VCA block, then given 20.8 dB of
gain in the MCI 2002 Op -Amp, to provide the nominal +4 dBv
output level. The MCI 2002 is a high voltage IC (bi -polar 36 V)
device, and clips at an output level of +28 dBv. believe the
console can deliver a maximum of +13 dBvtothe input of the
VCA block, thus giving a respectable 24 dB of headroom in
p
MEMO
_--
il
-I
29
tÑdB.i
_
--
rAtinf
-16.1;
jf
-_--
-____
yy''
_...
°°
-1
.
-
--
O%
I
-
-
-
1____.... __
__.
-
--
-
-
.,
-.
=-. -.- ..>Ut. -0. --
v
-
/
.
TIII
MEN
i1 ef1L111
_ Y_ill
...t_191114
lit
and out.
The control voltage range allows a mudest 12 dB increase
over the nominal fader position (control voltage = -.6 V), and
a 94 dB increase at maximum attenuation (control voltage =
+10 V). This agrees with the fader scales on the console
itself.
As had stated earlier, the distortion and noise contours of
the dbx 202 VCA are a function of the signal currents, as
established by the user -selected input and current to voltage
convertor resistors, R1 and R2. For the values shown, the
nominal input current (@ -11 dBv in) is 10 pa peak, and rises
to 100 pa at an input 20 dB over nominal. At the maximum
signal deliverable to the input, (24 dB over nominal) the
current rises to about 160 pa peak. The VCA output current is
nominally 5 pa peak, and can rise to a value of 80 pa, beyond
which the 2002 Op -Amp clips at its +28 output level.
At this point, I'm going to estimate the IMD and THD
contours for the dbx 202, at worst case fader positions, at
believe my estimates will be
these operating currents.
found to be at least 80% correct. would, however, suggest
that the reader either make measurements, or contact dbx,
should he desire more accurate information.
The results of my estimates are to be found in Figures 6
and 7. Note that the distortion products rise proportional to
the input level, and that the THD is consistently around 1/3
the IMD. This is the characteristic contour of error caused by
the resistive component of the base /emitter junctions of the
must warn
log /antilog transistors, as discussed earlier.
that the reader not yet jump to the conclusion that the dbx
VCA is at fault for the relatively high distortion. There are
other factors.
I
I
Figure 8
Output Noise vs Fader Position Relative to
Nominal Operating Fader Position for
Circuits of Figures 5, 10, 11 & 12
I
I
NOISE ANALYSIS OF FIGURE 5
The 2002 Op -Amp is specified to have an input noise
Hz (per input), and is operated at 20.8 dB
voltage of 14 ny
gain. Its output noise, with no input, comes to- 88 dBv, using
these parameters. To this must be added the amplified noise
of the 741s and the 202 VCA. For the sake of not getting
overtechnical, will refrain from the ritual of stating the
noise formulas, and just provide the results.
R-e/p 86
www.americanradiohistory.com
I
The 202 VCA /741 S combination yields an output noise of
-106 dBv @ maximum attenuation, -98 dBv @ nominal gain
( -6 dB) and -92 dBv at maximum gain ( +6 dB). When
amplified by the 2002 stage, and added to its noise, the final
noise analysis comes out as shown in the contour of Figure
8.
THE B & B /MCI CONNECTION
Now, let's find out what the B & B /MCI replacement
module can do. Figure 10 depicts the circuit involved.
Since the B & B device is incapable of gain, 6 dB of gain
preceeds the VCATT element. A +.6 V offset is introduced at
the control terminal to compensate for the additional input
gain. The net result is to trick the VCATT into thinking it is a
VCA. The cost of doing this is the reduction of the maximum
input level by 6 dB, to + 14 dBv. In this application the loss is of
no real consequence since the console can deliver only +13
dBv to the circuit.
SCALE FACTOR NON -LINEARITY
When started to test the B & B /MCI module, the first
thing noticed was that, although the gain vs. control voltage
was correct at 0 control volts, it was off by 2 dB at -.6 V
(maximum gain). This had the effect of reducing the
console's 12 dB gain reserve by 2 dB. Upon examining the
situation further,
found that the presumed 10 dB /volt
relationship was non -linear to the extent shown in Figure 9.
I
o0
I
I
&.1
710
1T7io
.
N7
''J
ir
,9 '' -' kI0 N \cA=5M:
JIII11102w{43ß:1:
i
_1
-14
1
:
MIN
__.
-
'ri
1
,
ii
.?-7
Porit
I
B & B /MCI NOISE
The noise performance of the B & B /MCI retrofit, however,
was a different story. Although the B & B module met its
published specs, the net result of the total circuit was a
disaster. The original noise performance of the console had
been degraded by from 5 to 7 dB, as shown in Figure 8. If 32
such channels were summed, at the nominal fader positions, the buss noise would come to -56 dBv from this source
alone. If all 32 signals had passed through these circuits
twice (once in miking and once in mixing), the buss noise
comes out -53 dBv, giving an output signal -to -noise ratio of
57 dBl You might as well take the dbx noise reduction off the
tape machine and put it on the console!
IoK
1-n
I
.51
IN
;aga
OUT
_
+.6V OFFSET
:+1
Sii
PLE FIVIO :I:INEPRIZY., 34 Z. vs: VCA
The scale factor log conformity error of Figure 9 was
confirmed by a close scrutiny of the B & B data sheet, but the
consequences are not explained. Note that the scale factor is
around 12 dB /volt in the center region, but falls to 6 dB /volt
at the extremes. This degree of error makes accurate
grouping impossible.
Let us make the assumption that two drum tracks were
assigned to one VCA group master. Let us further assume
that, in order to achieve a pleasing mix, that one drum fader
were near the top of its range, while the other were down by
15 or 20 dB. (A very common mixing situation.) Now let us
assume that the group master is moved up or down 10 dB (1
volt).
One drum track changes by only 6 dB, while the other
moves by 12 dB. The result, of course, is that the mix is
:
'
529
r1GUR.Q
CONTROL VOLTP,GE -10313/ VOLT
+tOV (+.0.1 NoMINALI
-.6v
46
ìo02
I
II
Inf
II
destroyed, since a 6 dB error has been introduced in the
relative balance of the two drum tracks.
As you can see, for successful grouping, the VCAs must
have excellent scale factor log conformity.
The Allison VCA -5A and M exhibit no more than 2% error
in log conformity, over the gain range of +35 dB to -100 dB. In
a similar mixing situation tothe one above, the tracking error
would be a maximum of 2% of the 10 dB change, or .2 dB. If
still greater accuracy is required, the scale factor can be
trimmed with a 50 -cent trimpot, to provide an essentially
unmeasurable error over the normal working range.
Getting back to the B & B /MCI retrofit, measured good
distortion parameters, as shown in Figures 6 and 7.
Definitely an improvement over the original performance.
BBB/
MCI
£ETRO F T
I
BACK TO DBX
Maybe we should give dbx another chance. Let's configure
it more in keeping with the ways its designer intended, and
see what happens. Starting with a criteria of no more than
.15% IMD for maximum input levels of +13 dBv, its input
resistor should be around 100 k. Next, the double Op -Amp
output stage is an unnecessary source of noise, as the dbx
VCA can couple directly into the 2002 Op -Amp, using it as a
current to voltage convertor, using a 500 k feedback resistor.
Offsetting the control voltage by -.6 V allows the VCA to take
more of the gain load, and places the VCA's unity current
gain point at the console nominal operating point, for
minimum distortion at the typical use point.
The improved circuit is shown in Figure 11. Now refer back
to the noise and distortion contours of Figures 6, 7 and 8 and
Voilai, not only is the distortion performance every bit as
good as the B & B /MCI, the noise has been improved by up to
14 dB over the B & B, and 7 dB over the original configuration. Can this be magic? Perhaps it is just a matter of applying
good engineering principles.
THE VCA -5M CONNECTION
Finally, the Allison VCA -5M VCA is plugged into the same
set of requirements. (Figure 12) In most applications, the
2002 following amp would not be required, since the VCA 5M has a voltage output capable of delivering +23 dBv
without additional circuitry. Since, in this case the console
continued on page 111
www.americanradiohistory.com
....
-
(Th
for the 4313, and a system design
incorporating in -line mounting of all
transducers for excellent stereo imaging. In
combination with the system's exceptional
transient response, these elements, according to JBL, make the 4313 a product capable
of outstanding accuracy, clarity and
LEXICON ANNOUNCES LOW -COST
DELTA -T MODEL 91
Lexicon's Delta -T 91 is a new low -cost
professional audio digital delay for small
sound reinforcement installation and pre reverb use in recording studios. It provides a
delay adjustable from 0 to 120 milliseconds.
Delta -T 91 has all the performance
specifications and features of the more
expensive Model 92 including: muting of
audio outputs during power up /down
sequences; automatic bypass; audio input
and output transformers, etc. The only
difference being a single output in the Model
91 versus two outputs in the 92.
The audio quality of Delta -T 91 meets the
power regulators, plus diagnostic aids for
rapid field service. Five -level headroom
indicator simplifies and verifies correct level
setting. XLR connectors are standard.
Delta -T Model 91 professional net price is
$985.00.
LEXICON, INCORPORATED
60 TURNER STREET
WALTHAM, MA 02154
(617) 891 -6790
for additional information circle no. 50
openness.
JBL engineers designed the powerful 10inch low frequency loudspeaker specifically
for accuracy and distortion-free performance in the 4313 enclosure. Features of this
component include a 3 -inch edgewound
copper voice coil and a heavy 1.5 -pound
cast magnetic assembly. The rear surface of
the cone is coated with an exclusive
damping formulation that provides the
precise mass and density necessary for
optimum bass performance.
JBL ANNOUNCES THE
4313 PROFESSIONAL SERIES
CONTROL MONITOR
James B. Lansing Sound, Inc., announces
the 4313 designed for control rooms,
mixdown facilities and any other professional applications in which a compact unit is
required. Features of interest include a new
highest professional standards. Total
distortion and noise is typically 0.06% at 1
kHz. Dynamic range is 90 dB and response
is from 20 Hz to 12 kHz, ±1 dB. Modular
construction, including pluggable ICs and
low frequency driver, especially developed
NEW!
Model 1100
Line/Microphone Audio Mixer
Phono Preamplifier, RIAA Equalization
Monaural Output Monitor Output
Rack Mountable Transformer Isolation
Equalization VU Meter
Six Lines Microphone Inputs
OUTSTANDING GUARANTEED PERFORMANCE
IMMEDIATE DELIVERY -- ECONOMICALLY PRICED
Specifications may be obtained from
PENH
LEADE
t
2
I
N
ADVANI-f_
3750 Airport Road
R-e/p 88
\ONIC5
D
T
i
Ogden. Utah 84403
c
tiNOLOG'/
(801) 392 -7531
for additional information circle no.
51
www.americanradiohistory.com
The 5 -inch mid -range loudspeaker is
housed in an isolated sub -chamber to
prevent interaction with the low frequency
driver. Powered by a 7/8 -inch copper voice
coil, the extremely stiff cone provides clear
sound reproduction with minimum distortion even at the highest volume levels. The
magnet assembly in this component weights
1- 5/8- pounds.
Constructed of phenolic -impregnated
linen coated with a thin film of aluminum, the
one-inch dome radiator provides high
acoustic output with great clarity. The
entire surface of the dome acts as a radiating
area, resulting in exceptional dispersion
characteristics. This component is powered
by a one -inch copper voice coil energized by
a 11/2 -pound magnet assembly.
The crossover network has special
phase- correcting conjugate circuitry to
ensure that the drivers operate in a manner
approaching the theoretical ideal through
r
Take an inside look at
GroundStar Laboratory
Ronnie Milsap's new facility in Nashville.
String Room
Ronnie had a dream. Call us about yours!
Consultation, Design, Equipment,
Custom Electronics, and Installation by
P.O. Box
Vì
40743
LLEY I UDi0
2821 Erica Place
Nashville, Tenn. 37204
615 -383-4732
Special credit goes to Rudi Breuer of Palm Dale, California for his invaluable design
help and superior construction work on Ronnié s facility.
MAS1ERS OF AURAL. GRA1Ii=ICA1iON
uiln,.nu,,, ,,,ch no S7
www.americanradiohistory.com
la, .,dd,tun,.,l
R
rrp 89
J
the transition frequencies. Built expressly
for use in dividing networks, the capacitors
are non -inductive and non -polarized types
with high AC current capacity. Level
controls allow individual adjustment of midrange and high frequency output.
The 4313 is available with a contemporary- styled walnut enclosure, constructed of
dense 3/4 -inch stock throughout to prevent
unwanted resonance; internal padding
absorbs spurious reflections and standing
waves. All components mount directly to
the baffle panel and are removable from the
front of the enclosure.
Weight of the 4313 is 42.5 pounds. The
dimensions are 223/4" x 14/4" x 9- 15/16"
deep.
JAMES B. LANSING SOUND, INC.
8500 BALBOA BOULEVARD
NORTHRIDGE, CA 91329
(213) 893 -8411
for additional information circle no. 53
TANGENT MODEL 1602a
Tangent Systems, Inc., announces the
introduction of the Model 1602a stereo
board designed to offer
mixing console
professional capabilities at a moderate
price.
The 1602a features include:
thanks to electronic
A solo function
FET switching, a sound engineer can
monitor any input or preview an entire
grouping, according to the manufacturer.
Pushing any solo button automatically puts
that channel into the headphones, no
matter what was present before.
100 mm Faders
Tangent's use of long throw 100 mm slide faders provides a
greater degree of control and more accurate
visual feedback.
effects, reverb,
Three effects sends
and monitor sends on each channel offer the
-a
-
-
-
HELLO
flexibility a sound person needs by acting as
three independent mixers- within -a- mixer.
each input has a pair
Channel patching
of access jacks for patching external effects
into a single channel.
the 1602a mixer line is
Modularity
totally modular for ease of servicing and
greater versatility.
Reverb
an internal option, the Tangent
reverb features a three -spring Accutronics
Type 9 chamber.
Rather than
Variable gain control
relying on pads, this control actually varies
the gain of the microphone preamp over a
-
-
-
-
delivers a typical noise level of -128.5 dBv
and total harmonic distortion checks in at
less than 0.004% at 1 kHz. The slew rate,
measured at any point in the audio chain, is
a minimum of 10 volts per microsecond.
The 1602a, engineered to meet professional standards at a moderate price, is
marketed through an exclusive network of
dealers, qualified in sound reinforcement.
TANGENT SYSTEMS, INC.
2810 SOUTH 24TH STREET
PHOENIX, AZ 85034
(602) 267 -0653
for additional information circle no. 55
40 dB range.
auxiliary inputs, transformerless mike
SOUND WORKSHOP ANNOUNCES
NEW 262 STEREO
REVERBERATION SYTSTEM
inputs and a phantom power capability are
standard.
The performance characteristics of the
1602a are reportedly impressive. The unit
Utilizing the latest in spring design for
professional studio applications, the 262 is
said to bring new performance standards to
reverb systems in the under $1,000
Numerous other features, such as
balanced inputs and outputs, expandability,
!
Just thought we'd remind you about the
Omnipressor
Eventide
The versatile unit which combines the characteristics of a
compressor, expander, noise gate, and limiter
in one
convenient package. Its dynamic reversal feature makes high
level input signals lower than corresponding low level inputs.
Musically, this reverses the attack -decay envelope of plucked
string and similar instruments, and gives the effect of "talking
backwards when applied to a voice signal.
265 WEST 54TH STREET
EVENTIDE CLOCKWORKS INC
Omr,oresso' is a trademark o' F:P' jr. ( ockworks Inc
NEW YORK. NY.
i
R-e/p 90
for additional information circle no. 54
www.americanradiohistory.com
(212) 581 -9290
CABLES EVENTIDE N.Y
Zucker also pointed out that the 934's
is improved over
traditional designs by the inclusion of the
Mantaray'". As a component of the 934, the
Mantaray constant directivity horn eliminates one of the most common problems in
all types of speaker designs
beaming, or a
narrowing of dispersion at higher frequencies. "The resultant benefit to the musician
is much greater latitude in speaker location
with more uniform audience coverage and
freedom from feedback," Zucker said.
An additional feature of the 934, the
company states, is the inclusion of the
Tangerine'", radial phase plug in the high
frequency compression driver. This phase
directivity control
-
category. The 262 features extended high
and low frequency response and a fullness
of sound associated previously only with
systems of substantially higher cost.
The 262 Stereo Reverb features an
extremely versatile and competent equalizer section. Two channels of EQ are
provided, with each channel allowing a plus
and minus 15 dB range over the high and low
frequency bands. Frequency selection is
fully sweepable from 50 Hz to 1 kHz (low
band) and from 500 Hz to 10 kHz (high
band). The EQ bandwidth is optimized for
proper contouring of the reverberant signal.
The 262 also allows dry/wet mixing (for
broadcast and disco applications), full drive
level into 600 ohm loads, LED level
indicators (for optimum dynamic range,)
active balanced inputs, and matched bi -FET
preamps for ultra-low noise performance.
The 262 Stereo Reverb mounts in a 3'/2-
inch rack space and sells for $700.00. It is
also available with transformer balanced
outputs and XLR connectors at $750.00.
SOUND WORKSHOP
PROFESSIONAL AUDIO
PRODUCTS, INC.
1324 MOTOR PARKWAY
HAUPPAUGE, NY 11787
plug enhances high frequency response, a
critical factor in high quality sound
reinforcement.
(516) 582-6210
for additional information circle no. 57
NEW MUSICAL SOUND
SPEAKER FROM ALTEC LANSING
A speaker system which offers portability
and high performance levels was Altec
Lansing's aim in designing the new 934,
according to Irwin Zucker, vice president
market development.
The 934's performance is indicated by the
efficiency level. With one watt of power the
934 can produce 101 dB SPL at four feet.
Time -Based Effects
The new 934 also includes a unique
crossover network which features a built -in
dual -band variable equalizer. The equalizer
... Without the Side -Effects.
Introducing the 440 Delay Line /Flanger from Loft Modular Devices.
There is a new solution for time -based effects. Filling
the gap between expensive digital lines and low cost
'black boxes', the Series 440 Delay Line /Flanger
delivers the amazing depth and dramatic realism
rightly associated with analog delay effects. Yet it
avoids so many unwanted side effects you expect
from analog and even some digital systems.
Now, you don't have to sacrifice the dimensional
impact of your music to severely limited bandwidths,
nor lose that bright crisp edge to compromised
electronics. Gone too, are the 'thumps', 'whistles',
background oscillations, quantizing noise, 'grainy'
digital audio, and other strange distortion you may
have noticed before. Even headroom, a problem
with so many units, is no problem with the Series 440
Delay Line /Flanger.
All you get is great sounding delay combined with
the creative flexability of VCO time based
processing. Mixed to any degree with straight delays
from .5msec all the way out to 160msec., VCO
processing permits such effects as resonant flanging,
Leslie -type sounds with different 'rotation' speeds,
vibrato, double tracking with realistic pitch and
timing errors, or a wide range of more subtle effects
to control the spatial perspective of your music. In
addition to the built -in VCO feature, control voltage
jacks allow further modification of the system's
special effects capability. Impressive? We think so,
but there is more. Why not check out the details at a
representative dealer near you.
The Series 440 Analog Delay
Line/Flanger is in stock and
ready for immediate delivery.
LET
MODULAR DEVICES
LOFT MODULAR DEVICES,INC. 91 Elm Street, Manchester, CT 06040 (203)646 -7806
for additional information circle no. 56
www.americanradiohistory.com
R
,
1,
91
can be defeated by means of a panelmounted switch, converting the equalizer to
full -range attenuator for the high frequency driver. The result is a new level of
Flexibility in network design for sound
reinforcement applications.
Built to meet the portable requirements of
a road tour, the 934's cabinet measures only
22" x 26" x 17 ". The cabinet is finished in
black leather-grained vinyl and is equipped
with a durable black knit grille. It is also "biamp ready", capable of receiving the Altec
1224A bi -amp in a pre -fabricated panel.
"The 934 is engineered for use in concert
halls, nightclubs, or discos," Zucker said,
adding, "but it's versatile enough to handle
any sound requirement."
a
called the vacuum shield mold process, or
"V- Pro," which involves placing a thin plastic
film over the green sand mold used in piano
frame casting. In the Vacuum -Process, by
using vacuum pressure, the sand fills even
the finest details of the mold for a perfect
casting. Contours are exact, and the
internal structure of the casting is more
uniform so there is less vibration loss. This
advanced method permits the reproduction
of design dimensions and shapes to more
accurate tolerances than ever before.
ALTEC CORPORATION
1515 S. MANCHESTER AVENUE
ANAHEIM, CA 92803
(714) 774-2900
for additional information circle no. 58
TECHNICAL CHANGES IMPROVE
TONE AND TOUCH OF YAMAHA
GRANDS
6'6" CONSERVATORY
MODEL INTRODUCED
-
Yamaha has improved the tone and touch
of its grand piano line with a variety of
technical changes, and has introduced a 6'6"
conservatory piano, the C -5.
Foremost among the technical advances
is a revolutionary new frame casting method
The "scale," defined as the engineering
and design that creates the sound, has also
been improved in the new Yamaha grands.
Major components of a piano's scale include
such things as string length, bass string
(Peet dKG's'Jlew(Professionals"
AKG is a research, development and manufacturing organization specializing in electroacoustic technology. Our designs have been
awarded over 600 transducer related patents. and our products have earned the
highest degree of user respect for quality
and dependability.
The AKG line of various microphone
models is considered to be the most sophisticated available for applications ranging
through the spectrum of professional uses
From studio, to in- concert recording and reinforcement, to location film sound...our
products can be called on to solve the most
difficult situations you may encounter. AKG has developed a
broad range of products to
meet your varying creative requirements and, as new audio
frontiers evolve, our engineers
will lead the technological
pioneering.
We set our goals rather high
R-e/p 92
and turn every stone to live up to, and improve upon, self -imposed challenges. We
constantly strive to advance beyond stateof -the-art developments. Some of these advancements you see illustrated below.
Loaded with practical, innovative features,
AKG's New Professional" microphones are
intended to further build upon the remarkable results achievable with the other AKG
"Professionals." Ask your dealer or write:
tLChl
AKG,
acoustics,
ANC, ;AN an,.
McKee Drive. Mahwah. N
J
07430
-
-
Winding tension can be adjusted more
exactly to maintain string elasticity and
achieve clearer sound, improved volume
and sustain.
The bridge, which transfers the string
vibrations to the soundboard, will be more
efficient in that task, thanks to a new shape
and a greater contact area. The soundboard
itself has also been improved. In all grand
piano models, the apex of the soundboard
crown is now located at a more centralized
point under the bridge to enhance tone
quality and sustain.
The touch of the new Yamaha grands
stays smooth indefinitely because a new
method for plating the action center pin
surfaces prevents roughness even after
long -term use. The nickel -plated tuning
pins, which were so highly appreciated in
the previous C- series, are used in all of the
new grand pianos. Hard steel insets in the
frame capo bar section of the plate prevent
wearing of the bearing by the strings, and
assures a more precise string support point
for a clearer tone with less unwanted noise.
As exciting as the technical changes in
existing Yamaha models is the addition of
the 6'6" conservatory piano, the C -5, to the
line -up. The plate is made by the new "VPro" and the C -5 features such case
embellishments as a bevelled topboard and
spade legs on the bench.
YAMAHA INTERNATIONAL CORP.
P.O. BOX 6600
BUENA PARK, CA 90622
for additional information circle no. 60
PHILIPS AUDIO VIDEO SYSTEMS CORP.
91
construction and bridge shape.
The bass and mid -range areas of the new
pianos, excluding the G1 -J and C7 -D which
were recently improved, will feature longer
strings for improved bass volume and
sustain and a smoother transition to midrange. Bass strings are made by wrapping
plain music wire with copper wire
a
method which results in muddiness if the
wire is wound too tightly, or buzzes and
rattles if the winding is too loose
are now
made through a more precise technique.
(201) 529 -3800
The Mark of
Professional Quality...
in microphones, headphones,
phonocartndges, reverb units.
www.americanradiohistory.com
MCI'S JH -600
STOCK AUTOMATED CONSOLE
Said to be the first stock automated
console, the JH -600, like the predecessor
JH -400 and JH -500, is an in -line console with
each I/O module containing one complete
mike channel and one complete remix
channel. On the JH -600 the VCA fader
assemblies have been mechanically separated from the rest of the module. It comes in
two frame sizes, the JH -618 (18 inputs) or
JH -636 (36 inputs).
Some of the features designed into the
new desk include differential line inputs, and
optional differential mike preamps. There
are up to 36 channel outputs, high and low
pass filters, 24 channel busses with panning,
and six sends. The console also has
momentary short travel mute switches,
to 20 msec, release times .1 to 2 sec. The
unit features a switch whereby the user may
select the function of the VU meter. You
may see the actual output level or see the
amount of gain reduction. With zero gain
reduction the needle would point to zero
level. At 3 dB of gain reduction the needle
would point to -3 dB, indicating a cut of 3
dB. The meter is illuminated, and uses
special ballistics for better movement. Rear
connection is made via barrier strip.
balanced push/pull output, and multiway
connectors for all rear panel connections.
Another highlight of the JH -600 is the
optional true parametric equalization. This
means that there are three separate
controls for frequency, amount of boost,
and Q (sharpness) that are not interactive.
The JH -600 features MCI's JH -50
Automation as standard equipment. The
automation gives the console such capabilities as discrete grouping and Stereo In Place
Solo, as well as the automation functions.
Basic automation modes include READ,
WRITE and UPDATE as well asn an
independent command for MUTE WRITE,
and REWRITE capability. Automation is
controlled by sets of three buttons and three
LEDs for each I /O, Master and Group fader
and each Echo Return. Smooth transfer
between modes of operation is automatic.
The standard JH -600, as an automated
full- featured desk is available at $28,000.00
for a Model JH- 618- 18 -VU.
MCI
4007 N.E. 6TH AVENUE
FT. LAUDERDALE, FL 33334
(305) 566-2853
for additional information circle no. 61
TRACK AUDIO
LM -1R COMPRESSOR /LIMITER
The LM -IR features extremely low noise
and distortion figures. The unit is rack
mountable and was designed with flexibility
in mind. Variable functions include
compression 2:1 to infinity, attack times .2
btx presents
the 30 track
audio recorder
' he btx 4500 SMI'
Professional net price has been set
around $350.00. Dealer inquiries are invited.
TRACK AUDIO, INC.
33753 9TH AVENUE SOUTH
FEDERAL WAY, WA 98003
(206) 838-4460
for additional information circle no. 63
KLARK -TEKNIK DN -34
ANALOG TIME PROCESSOR
Hammond Industries, Inc., the exclusive
United States distributor for Klark- Teknik,
announces the DN -34 Analog Time
Processor is now available for delivery.
The DN -34 is described as being capable
of producing numerous time related effects.
Among others, these effects include
I t- ugerlotlung system leis you operate any two
multi -track recorders in tandem for 19, 22, 30 or 4o -track capability.
Using standard SMI'TL time axle written on one t rat k of eat h
mat hine, any two recorders may be sync hrunited, ¡minding video to
audio. You can even mix makes, formats, spuds, and numbers of
tracks, with or without servo controlled capstan drive I he btx 4500
is a micro- pr( Kessor based system capable of t rat king within 50
of an actual mechanical lock. it's an ec ¡mount al direi t
-Winds
plug-in system that's easy i
r
MA%TEP
CODE
sow'
CODE
The btx Corporation
438 Boston Post Road, Weston, MA 02103
(o17) 801-1239
for additional information circle no. 62
www.americanradiohistory.com
accurate sound clarity and wide frequency
response for critical recording sessions.
Large 50 cm diameter cone type drivers
have a sensitivity of 110 dB/mW, impedance
of 28 ohms at 1 kHz and frequency response
of 20 - 20 kHz. Rated output is 10 mW, with a
maximum of 100 mW. The DR -6M weighs
i
350 grams.
Suggested retail price of the DR -6M is
$55.00.
flanging, phasing, double and triple tracking,
vibrato, doppler/leslie and chorus.
The design of the DN -34 incorporates a
compander and peak limiter so the effects
can be achieved cleanly and noiselessly. All
of the effects can be achieved without the
need for additional outboard equipment
and/or mixer console facilities.
The DN -34 is available from Klark -Teknik
franchised dealers and has a suggested
retail price of $1,600.00.
ances or off -the -air.
The lightweight, folding headphones,
which will fit in a coat pocket, provide
SONY INDUSTRIES
PROFESSIONAL AUDIO
PRODUCTS DIVISION
9 WEST 57TH STREET
NEW YORK, NY 10019
(212) 371 -5800
for additional information circle no. 66
CORRECTION
Unfortunately, a typographical error in
our December, 1978 issue resulted in an
incorrect price listing on a New Products
item.
The new Shure Monitor Speaker,
Model 703, should have been shown
with a user net price of 5370.00.
HAMMOND INDUSTRIES, INC.
KLARK -TEKNIK DIVISION
155 MICHAEL DRIVE
SYOSSET, NY 11791
NEW SHURE MONITOR
SPEAKER FEATURES UNIQUE
VARIABLE DISPERSION CONTROL
(516) 364 -1900
for additional information circle no. 64
The new stage monitor speaker with a
unique high frequency variable dispersion
control allows the user to tailor the
horizontal sound pattern to a variety of
coverage requirements.
NEW SONY HIGH- PERFORMANCE
MONITOR HEADPHONES
Sony's new DR -6M dynamic stereo
headphones are uniquely suited to sound
monitoring while recording live perform-
The Quad-Eight Story You've Never
Heard.
Introducing the precision Quad -Eight Equalizers. Three and
four -band configurations with integral Hi and Lo -Pass filters. Each
available in 19" rack and standard console -1 /2" mountings. Contact
us for all the juicy details.
1
2
re
L
For the Artist in Every Engineer.
I
Quad -Eight Electronics
Quad -Eight International
11929 Vose Street, North Hollywood, California 91605, (213) 764 -1516 Telex: 662 -446
R-e/p 94
for additional information circle no. 65
www.americanradiohistory.com
This versatile, compact two -way monitor
speaker is called the Shure Model 703 and is
designed to provide control of high
frequency dispersion through the use of
removable acoustic wedges. This feature, in
conjunction with the capability of two tilt
angles, provides the user with four possible
coverage selections.
Sound can be dispersed over a wide 120°
angle to cover several performers or to
permit greater freedom of movement on
stage, or a tight 60° angle for narrow,
"personalized" coverage and minimum
sound spillover. The speaker can also be set
on its back at the front of the performer for
short throw (close use) or placed upright for
long throw coverage when the performer is
farther away.
Another important feature of the Model
either a stereo power amp or conventional
musical instrument amps; in a P.A. system
for feedback suppression; as general
purpose patchable equalization for recording studio or broadcast applications; or for
room equalization in studio control rooms
703 is its shaped frequency response, which
properly emphasizes the presence range
and effectively eliminates undesirable bass
boominess. This feature not only enables
the Model 703 to cut through intense
ambient sounds on stage, but also provides
a very natural sound to the performer.
The Model 703's high frequency driver
and two eight -inch heavy-duty speakers
provide excellent sound reproduction.
Power handling capacity is 100 watts of
continuous program material. The speaker
is an eight -ohm system and can produce 97
dB SPL with a one -watt input at four feet.
Overall dimensions of the speaker
enclosure are 283 mm (11 -1/8 in.) H x 587
mm (23 -1/8 in.) W x 438 mm (17 -1/4 ") D.
Weight is 14.3 kg (31 -1/2 lbs.). User net
price for the Model 703 is $370.00
SHURE BROTHERS, INC.
222 HARTREY AVENUE
EVANSTON, IL 60204
f,,, eddrUUn.11 inh,rmalinn circle no 67
FURMAN SOUND STEREO
PARAMETRIC EQUALIZER /PREAMP
MODEL PQ -6
The Furman Sound PQ -6 is the equivalent of two Model PQ -3s in one chassis,
resulting in substantial savings to those
users needing two channels of parametric
equalization. Among its uses are: a stereo
musical instrument preamp for use with
LOADED...
THE 600 WAIT
NO-OPTION AMP.
nign- Pulver
People
amp with low distortion that s loaded with options
and doesn't cost an arm and a leg? We listened
to them and set out to build The Complete Amp'
with reliability, power, specs. features. and price.
We've succeeded. Our reputation has been built
on the design and construction of cost -effective
gear combining maximum performance with simplicity and reliability Now OSC offers a package
you cant find in any other amp. REGARDLESS OF PRICE OR OPTIONS. The A 8.0
delivers 300 watts of clean power to each
channell20 -16kHz with less than. 09 %THD
rising gradually to 0.2% THD at 20 kHz into 4
ohms) and 600 watts into 8 ohms with the same
specs in the bridged -mono operation.
Features include: PowerLimit Controls: Fan
Cooling: 3-way Load Protection: LED displays for
level. distortion, and limiting indicators. Balanced
Inputs with XLR type 3 -pin connectors. and
Outputs with 5 -way binding posts, phone jacks.
and speaker protection fuses. Ask your Pro-Audio
Dealer about the A 8.0 or write directly to
us for a free brochure detailing the incredible features and specifications of this
exceptional new power amplifier from OSC.
AUDIO PRODUCTS
1926 Placentia Avenue
Costa Mesa. CA 92627
714,645 -2540
for additional information circle no. 68
www.americanradiohistory.com
R
/p 95
SWEDISH
STEAL.
St_LLLLLL
I
Ltt4-
,`tt_LLLLLL
I
L L LLLL
.
<
,rLLLL,Lt
,
n
n
t
.,r
-tr
',,',71:,-L LLt
rfi
,
'
Oa
a.;
.:..K
'+r).:nn.»
tr Mena
-H
-r
t,+-0{y
t,.
.,a.
y{ /
', I
L
1
,I
r
1
r`M
P.
- _Mat
or even in home living rooms.
Parametrics are not limited by a fixed
number of frequencies as are graphic
equalizers. The Furman PQ -6 has three
continuously variable and broadly
overlapping frequency controls per channel
so you can zero -in EQ exactly where you
want it. Each band can be boosted by up to
20 dB or cut to complete cancellation (more
than 40 dB). Bandwidth controls adjust the
extent to which surrounding frequencies
are affected, from 1 /10 of an octave to over
four octaves with any band. Other features
include: Bypass switches, high and low level
inputs and outputs, 1/4-inch phone jacks,
and a detailed instruction manual. The PQ -6
is 19 -inch rack -mountable, and is available in
115 V, 60 Hz and 230 V, 50 -60 Hz versions.
Specifications include:
Frequency Ranges: Bass 25 -500 Hz, Midrange 150 -2,500 Hz, Treble 600- 10,000 Hz.
Equalization: +20 dB boost, - dB cut, all
ranges. Bandwidth: Boosting, 1/3 to 4
octaves; Cutting, 1 /10 to 1 octave ( "Q"
adjustable from 0.2 to 3.8). Input: 100
kilohms unbalanced, with maximum input
level before clipping at 1 kHz, 4.9 Vrms for
High Level In; 430 Vrms for Low Level In.
Output:
10
ohms unbalanced, with
maximum output level of 8.3 Vrms ( +21
dBm) into minimum terminating impedance
of 600 ohms. Total Available Gain: Low
Level In 26 dB; High Level In 6 dB (with EQ
set flat or bypassed).
Frequency Response: ±%2 dB in Bypass or
with all Equalization controls set to 0, from
20 Hz to 20 kl-iz. Signal -To -Noise Ratio: 109
dB in Bypass; 99 dB with EQ in and set flat
(noise measured with High Level Input
shorted to ground, unweighted, from DC to
80 kHz). Distortion: .015% in Bypass; .025%
with EQ in and set flat (THD measured at 1
kHz at +20 dBm output and 600 ohm
termination).
Distributed by:
ROTHCHILD MUSICAL.
INSTRUMENTS
10 IVY LANE
ENGLEWOOD, NJ 07631
(201) 871-3366
for additional information circle no. 70
THE PML
DC-63 CONDENSER.
More Performance. Less Money.
Just one in a tough, practical &
precision line of professional
mikes. Handcrafted in Sweden
since 1941.
PML Worldwide Marketing:
Creative Trade, AB,
Knutsgatan
6.
S-265 00. Astorp, Sweden. Tel: 464251521
U.S.
Distributor:
Cara International Ltd.,
4145 Via
Marina. No. 120, Marina Del Rey, CA 90291.
(213) 821.7898
OTARI ANNOUNCES 8:1
IN- CASSETTE DUPLICATOR
WITH CASSETTE MASTER
AND FIVE SLAVES,
THE DP- 4050 -CCF
Otani has announced the availability in the
U.S. of a second version of its DP -4050 in-
cassette duplicator which features
a
cassette master and five slaves with ferrite
heads. Designated the DP- 4050 -CCF, this
version complements the DP- 4050 -OCF,
which has an open -reel master and six
slaves, and has gained wide acceptance for
its rugged reliability and ease of operation by
non -technical personnel.
Duplicating speed ratio is 8:1 and all
R-c/p 96
www.americanradiohistory.com
tracks are copied simultaneously. Thus, five
C -30 copies, for example, can be made in
under two minutes.
A major benefit of the DP -4050
duplicator, according to the manufacturer,
that each plug-in slave unit is completely
independent of the others and contains its
own servo-controlled capstan motor. The
advantage of this approach is that if one of
the cassettes should jam during duplication,
that slave can be stopped while the other
slave units continue duplicating without
interruption.
Other major DP- 4050 -CCF benefits are:
Professional quality and reliability;
duplicates C -30, C -60 and C -90 cassettes;
and master and slave transports have long
life hot -pressed ferrite heads.
Cassette formats duplicated are 1/4- or /2track mono or 1/4-track stereo. All tracks are
recorded in one pass
cassettes don't
have to be turned over. Bias adjustments
are conveniently located behind a panel on
is
-
1
-
the front. Photocell sensing provides
automatic rewind of master cassette.
OTARI CORPORATION
INDUSTRIAL ROAD
SAN CARLOS, CA 94070
981
(415) 593 -1648
for additional urforrnation cede no
71
MXR FLANGER /DOUBLER
The MXR Flanger/Doubler is a versatile
signal processing device which produces a
wide variety of time delay effects, and is
instantly switchable between the Flanging
and Doubling modes. The time delay in the
Flanging mode is from .25 to 5 milliseconds,
and the time delay in the Doubling mode is
from 17.5 to 70 milliseconds.
The MXR Flanger/Doubler features
Manual Control over the delay time, a Mix
control (between the dry and undelayed
signals), Sweep controls over both width
and speed, and a Regeneration control for
additional intensity. The Flanger/Doubler
can produce many varieties of flanging, hard
reverberation, and numberous types of
doubling which include subtle chorus
effects.
The unit is rack mountable, and features
instrument level inputs and outputs on the
front, and line level inputs and outputs on
the rear, making it equally adaptable to both
stage and studio use. The Flanger /Doubler
previous methods used to accomplish
similar kinds of tasks by enabling the user
to control the frequency spectrum tonally
and spatially at one time, from the same
piece of equipment. By combining the
functions of equalization and delay in one
piece of equipment the user has the ability
to vary the delay rates of several frequency
bands as compared with other delay
devices which provide a single selected rate
of delay over the entire frequency spectrum.
units are used to vary the apparent room
environment acoustically.
also features LED sweep indicators as well
as power on and effects in/out indicators.
Voltage control terminals on the rear panel
provide external delay control, and the
ability to gang two units together for stereo.
POLYPHONIC SOUND INDUSTRIES
104 RIDGE ROAD
NO. ARLINGTON, NJ 07032
The units are said to improve on
(201) 997 -6666
for additional information circle no. 73
MXR INNOVATIONS, INC.
GOODMAN STREET
ROCHESTER, NY 14607
247 N.
(716) 442 -5320
for additional information circle no 72
POLYFONICS PY -10 and PY -5S
ACOUSTIC SIMULATORS
ANNOUNCED
Designed to be used for room simulation
and sound enhancement their application
can vary from correcting overly close
microphone techniques in studio use to
creating an ambience effect on too dry
sounding tapes. In live applications the
Should you buy the new Sound Workshop 262
Stereo Reverb or should you resile your bathroom?
That's a tough decision to make. Perhaps you
stay up nights pondering this very question.
But please take the time, right now, to consider
this important matter.
Think how great your voice sounds when
you're lathering up in the shower. It's because
the hard, ultra- smooth surface of the tile takes
your normally lifeless voice and bounces it
Uaeritt4b9P
-
loft
back and
adding depth and magnitude.
Its called natural reverberation.
There are, and have been, devices available
which simulate natural reverberation. But a
professional quality studio reverb (that sounds
as natural as your bathroom) used to cost well
over a thousand dollars.
Sound Workshop introduces the new
262 Stereo Reverberation System ... for well
under a thousand dollars. We thought you'd
like to know.
MAW
I.
». s1.00.PFM1111
IMO
a-
SoundWor Shop
Ì.
i
-
l
Sound Workshop Professional Audio Products, Inc.
1324 Motor Parkway, Hauppauge, New York 11787 (516) 582 -6210
for additional information circle no. 74
www.americanradiohistory.com
processing loops, as well as for internal
circuitry providing octave -wide equalization, sub -sonic filtering, and three -way tape
recorder dubbing and monitoring, has been
announced by Soundcraftsmen. The new
model is called a Signal Processor/Preamplifier, model SP 4002, with rack -mount front
panel, handles, and walnut -grained
decorative side panels.
Two ultra -sensitive phone preamps with
variable cartridge loading 50 to 800 pf, and
variable impedance 100/47 k, will accept any
type cartridge with output from 0.28
millivolts to 300 millivolts. Each stereo
phono preamp is completely separate, with
its own inputs, outputs, and its own
THE AUDIOARTS
MONITOR 10 SYSTEM
outputs (16 channel configuration), five
knob EQ, modular design, direct output
control on each input (for spot monitors,
effects send, etc.), meters for all output
channels and separate solo meter.
This newly announced product is a
professional stage monitor mixing and
distribution system which was designed to
maximize flexibility while maintaining logical
flow of operation. The Monitor 10 has been
carefully engineered to assure that reliability
and performance have not been compromised. Special attention has been paid to
achieve high speed, low noise electronics
with excellent overload recovery characteristics and artifact free operation.
The Monitor 10 system features five subgroup busses, ten mix busses, 26 inputs, 26
AUDIOARTS ENGINEERING
286 DOWNS ROAD
BETHANY, CT 06525
(203) 393-0887
for additional information circle no. 75
SOUNDCRAFTSMEN
SIGNAL-PROCESSOR/PREAMP
A new preamplifier with front panel
pushbutton switching facilities for outboard
NOISE GATE
OMNI CRAFT'S MODEL GT -4
independently variable ±20 dB gain stage,
300 millivolts overload capability, and a
phenomenal 97 dB signal -to-noise ratio.
Either or both stereo phono preamps may
be driven by variable reluctance, moving
magnet type cartridges or moving coil
cartridges with 0.28 millivolt or higher
output.
The signal path is logically routed via
clearly labeled pushbutton switches from
any one of six input sources sequentially
through a sub -sonic filter, two external
processing loops, an equalizer, and a mono
A + B mixer, to either the two tape outputs
or the two line outputs. Tape dubbing and
tape monitoring may be switched in and out
with equal facility, and any source may be
listened to normally during the tape dubbing
process. All processing facilities may be
inserted into the tape dubbing circuitry as
desired by pushbutton as labeled. Dubbing
can also be accomplished without
processing, while listening to a different,
fully processed source signal at the user's
option.
Built into the new preamp is
professional quality
equalizer with 15 dB
per octave, and up
boost or cut with
a
octave -wide graphic
minimum boost or cut
to 22 dB per octave
all octaves full, LED
indicators for precise input -to- output
balancing, precision -made wire wound
passive inductors for optimum bandwidth
curve formulation and consistency,
READY TO MOUNT
-
separate spectrum -level control for precise
control of the input to output gain of each
channel, and EQ signal -to -noise ratio better
than 114 dB at full output.
SELF POWERED.
FOUR CHANNELS IN ONLY
1
-3/4 INCHES
OF SPACE.
60Db OF ATTENUATION.
DIRECT AND KEYED INPUTS.
ADJUSTABLE THRESHOLD AND RELEASE.
CONTRIBUTES NO NOISE OR DISTORTION.
S
395.00
FOR
4 CHANNELS.
OMNI CRAFT INC. RT. 4 BOX 40
LOCK PORT, IL. 60441 815 838-1285
Rr./p98
for additional information circle no. 76
www.americanradiohistory.com
Headphone amplifiers for two headphones from 80 ohms to 200 ohms
impedance provide excellent monitoring
facilities, with one headphone muting the
speakers by interrupting Line 1 output.
Also, front panel jacks are provided for a
third tape recorder in parallel with tape
recorder 2 for easy input and output access
when desired.
The volume control is a high precision
click -stop resistance notched stepped
potentiometer, to control total system gain
from infinity to maximum 71 dB. The click
stops have been selected in varying degrees,
THE WORD FOR TODAY
IS
"NATURAL"
[More or Less]
For years, all reverbs were just
that - simply reverbs - until
development of the MASTER ROOM.
MASTER -ROOM claimed Natural
from approximately
1
dB upward, so that
the audible output level increase or
decrease from 1 click stop to the next
remains constant. Each click stop has its
own separate resistance network so that a
precise percentage of output can be
consistently applied at the user's
preference, with specific and repeatable
variances in level.
The signal processing paths have been
carefully plotted to enable the user to take
full advantage of the flexibility of the
pushbutton patching capabilities of the
signal processing preamp. The source
signal, coming from either Tape
Tuner, Aux., Phono
1
1,
Tape 2,
or Phono 2, is
immediately routed to the sub -sonic filter,
thence forward to External Loop 1, Loop 2,
Equalizer and Mono A & B mixer. At that
point a selection is made as to the Tape
Outputs or the Line Outputs. The selection
of "Tape Record" applies the processed
signal, (if processing is desired, and
according to which buttons are depressed),
to the Tape Outputs only. Line Outputs
remain live, but provide an unprocessed
source signal only. If Tape Record is not
pushed in, Line Outputs receive the
processed signal automatically. Thus,
during tape dubbing processing, it is
possible to listen to an unprocessed source
signal as it is put out on the Line Outputs.
During tape recording or tape dubbing, by
depressing Tape Monitor 1 or Tape Monitor
2, as appropriate, the recorded processed
signal can be listened to through the Line
Outputs or Headphones.
SOUNDCRAFTSMEN, INC.
2200 S. RITCHEY STREET
SANTA ANA, CA 92705
side, cold-weather applications in high
impedance systems are included. The 18and 20 -gauge neoprene -jacketed constructions feature an inner conductive -textile
wrap shield and a tinned- copper serve shield
for 100% coverage. The 20 -gauge construction (No. 9394) is 0.190 inch diameter; the
18 -gauge version (No. 9395), 0.235 inch.
Norminal capacitance between conductor
and shield is 55 pF /ft. for both.
For low impedance systems, three vinyl -
Sound and demonstrated what is
meant by that with its unique,
full ambience properties of:
Natural delay prior to first echo
Natural group of first order
echoes
Natural build -up in amplitude
Natural pattern random diffusion
Natural build -up in echo density
Natural proportioned decay
Natural flat frequency response
Natural smoothness without
limiting
jacketed configurations, offering low
capacitance, low loss, light weight, and small
diameter, also are available in the new line.
Single- conductor design No. 9396 uses a 25gauge stranded cooper/copper- covered
vinyl -insulated conductor with a tinned
copper serve shield and a gray jacket.
Diameter, 0.100 inch; nominal capacitance
75 pF /ft.
Two- and three -conductor 24 -gauge
designs feature stranded tinned copper
vinyl -insulated conductors with bare copper
spiral shield and matte white and matte gray
vinyl jackets. The two -conductor design
(No. 9397) is 0.176 inch diameter; the three
conductor (No. 9398), 0.186 inch. Both have
a nominal capacitance between conductors
of 40 pF/ft.
Single- conductor neoprene constructions are offered in lengths of 500 to 1,000
feet. Vinyl- jacketed designs come in lengths
of 100 and 250 feet (No. 9396) and 100, 500,
and 1,000 feet (Nos. 9397 and 9398).
-
As a result of MASTER-ROOM,
"NATURAL" is now the key word
in reverberation equipment, but a
word that is too often used
without regard to its true meaning.
So thanks to all who have
helped to make "NATURAL" Ike
word in reverberation devices.
From the originator... the one
who backs it up with performance.
-
BELDEN CORPORATION
2000 S. BATAVIA AVENUE
GENEVA, IL 60134
for additional information circle no. 78
INTRODUCES TWO BASS
GUITAR SPEAKER SYSTEMS
E-V
(714) 540-4961
The two new systems, designated the
B115 -M and B215 -M, are both two -way
systems with the B115 -M having a single
EVM -15B speaker while the 8215 -M has
for additional information circle no. 77
BELDEN DEVELOPS NEW
SERIES OF SHIELDED
MICROPHONE CABLES
A new series of single and multi
conductor shielded microphone cables has
been introduced by Belden Corporation's
Electronic Division.
Two single- conductor designs for out-
two. Both systems utilize the vented -cone
mid -range driver. The VMR is said to offer a
much improved high end over that normally
found in single driver enclosures. The
effects of the VMR can be tailored to the
bass player's requirements via a rotary
MICMIX Audio Products, Inc.
2995 Ladybird, Dallas, TX 75220
(214) 352 -3811
R-e/p 99
www.americanradiohistory.com
We are pleased to
announce that these
studios have already
chosen the new Studer
A800 multitrack tape
recorder.
control mounted on the front of the
enclosure.
The B115 -M, according to the company,
has the cleaner sound preferred by many
jazz bassists, and is also quite at home in the
studio. The B215 -M has a heavier sound,
and its increased power handling capacity
(400 watts vs. 200 watts for the B115 -M)
make it the logical choice for the rock
musician.
Both speaker systems are constructed of
3/4" plywood covered with durable black
vinyl. All edges are aluminum trimmed, and
the metal mesh grille protects the drivers
making them suitable for use with all
microphone holders, flexible connectors or
microphone attachments.
Model PSC -3 is specifically designed for
use by seated performers or in instrument
miking, and extends from 26 inches to a 66inch height. It telescopes to a space -saving
22 inches for transportation.
Model PSC extends from 35 inches to 63
inches, and folds into a 32 -inch length for
compact shipping. It weighs 41/2 pounds.
ATLAS SOUND
10 POMEROY ROAD
PARSIPPANY, NJ 07054
(201) 391 -8298
for additional information circle no. 83
-concluded from page 39GEORGE MARTIN
CA
Lc`pn
,l'a
M°"y
11
N
``
09
vol;
ROF
oc,
R°rb,
\I,102'
i
Moelni 13215M
from accidental damage. The B215 -M is
equipped with the heavy -duty casters and
both systems have integral handles for easy
set -ups and tear -downs.
Suggested prices for the B115 -M and
B215 -M are $650 and $930 respectively.
ELECTRO- VOICE, INC.
600 CECIL STREET
BUCHANAN, MI 49107
W`c`P
(616) 695 -6831
for additional information circle no. 82
NetWz631-4
\1,1zIes
C"06:
SkN6°s
Foc
ACnt
model
(oky°
0
'`4
i
SN
\Ne°x
tR
Rar-`,a`
60)3k
1o`
w
VI °fco
ae
_,;nco
F
W3
bly, providing for
positive- locking
1-
S
S t
S°1
92n
C"c7'-
?NC'
*1\k
zsa
cd°n
iNel
ATLAS SOUND PORTA -SERIES
MICROPHONE STANDS
IMPROVEMENTS ANNOUNCED
Improvements
in its recently -released Porta -Series include the addition of a grooved
cam, machined into the tube assem-
Po(t.a
A1`
Vc
SS)'v`)c\'°s
D)
and non-rotational
brake action, while
new tempered springs within the tripod assembly guarantee increased
stability.
The popular and
economically-pri -
ced Porta -Series
models PSC and PSC -3 acknowledge the
trend among performers to use a single unit microphone stand with foldable base.
Each offers instant set -up and compactness
for minimum transportation expense.
The PSC and PSC -3 feature die-cast
baked epoxy bases finished in non -reflective
black. In addition, the stands' vertical tube
assemblies are chrome -plated with all-metal
"grip-action" clutches and the industry's
standard % "-27 male thread termination,
R-e/p 100
www.americanradiohistory.com
GM: The kid who wants into it thinks he has
a chance of being number one. He thinks
he's going to buy that ticket, too. The other
problem is that standards have gone up
generally, so it's very hard to break through.
Tom: It is getting to the point a garage band
can't break into recording?
GM: I don't think so. I think there is always
room, particularly now. Trends reach
plateaus; we're in a plateau now. There's a
greal deal of very good music, but nothing is
utterly fantastic. Obviously it's difficult to
break through because the level of quality is
so high.
Tom: What do you think of disco?
GM: It's super. I love it, I love dancing to
disco ... well, I better put 'moving to disco,' I
really can't dance. As a body propellent I
think it's great.
Tom: Do you see it being with us for a while?
GM: Like all things it has an influence on
music. And like all things it will have an effect
on all kinds of music. It's a good tool to use.
Tom: Are you interested in someday
becoming the president of your own record
company again?
GM: Oh, God! Well, what do you do when
you get too old and sick and tired to make
records? I think it's obvious I have a role to
play in the record business somewhere. I'm
quite happy doing what I'm doing at the
D OD
moment.
R-eip BACK ISSUES AVAILABLE
-
whit. They Last
Limited Quantity
Volume 6, #2
April. 1975
Volume 6. #3
June, 1975
Volume 6, #6
December. 1975
February, 1976
Volume 7, N1
Volume 7, 03
June, 1976
August, 1976
Volume 7, e4
February, 1977
Volume 8, #1
June, 1977
Volume 8. #3
August. 1977
Volume 8, e4
Volume 8, #5
October, 1977
Volume 8 #6
December, 1977
$2.50 each
Mall orders to: R-e /p
P.O. Box 2449 Hollywood, CA 90028
Foreign orders payable in U.S. funds only by
bank check or money order.
RECORDING
engineer / producer
PROFESSIONAL
1978
INDEX OF FEATURE EDITORIAL ARTICLES
TITLE
AUTHOR
ISSUE
DATE
Howard Cummings
9 -6
December, 1978
Tom Lubin
9-5
October, 1978
Tom Lubin
Howard Cummings
9 -4
9-3
August, 1978
June, 1978
Howard Cummings
Jim Furman
9 -2
9 -1
April, 1978
February, 1978
Bob Marich
Tom Lubin
Woody Smith
9 -6
9 -5
9 -3
December, 1978
October, 1978
June, 1978
Paul Laurence
9-6
9-2
April, 1978
INTERVIEWS
Geoff Emerick, Grammy Winner
The Bee Gees, Albhy Galuten and
Karl Richardson
Bill Szymczyk, Ed Mashal,
Joe Walsh and The Eagles
The Motown Sound, Al Stewart
Fleetwood Mac's "Rumours,"
with Richard Dashut, Ken Caillat
Fred Catero at San Francisco's Automatt
STUDIOS:
DESIGN /ACOUSTICS /OPERATION
Soundcastle Recording
San Francisco Area Small Studios
Studio Acoustic Design
RECORDING TECHNIQUES
Re- Orchestrating
Recording the Cathedral Pipe Organ
STANDARDS,
SPECIFICATIONS AND TESTS
IHF Amplifier Standards
Magnetic Reproducer
Equalization Accuracy
Mathematics for Sound Systems, Pt. II
Noise Index Measurements
A Standard Digital Interface
for Peripheral Equipment
Console Noise Specifications, Part II
TROUBLESHOOTING
ALIGNMENT, MAINTENANCE
Impulse Alignment of
Loudspeakers and Microphones
Speaker Wire
Stabilizing Op -Amps
Audio Shielding, Grounding & Safety
CONCERT
SOUND REINFORCEMENT
The Doobie Brothers Touring System
Time Delay In Sound
Reinforcement Systems
MASTERING TAPE
Your Studio Mastering Tape
RECORD PRESSING /MASTERING
The Record Pressing Problem
Disk Mastering
The Buchmann -Meyer
Light Pattern Technique
DIGITAL RECORDING
Digital Audio Report
Digital Audio Standards
The Soundstream Digital System
Digital Report
The Crystalab Programmable
Parametric Attenuator and
Digital Logic Control System
A Standard Digital Interface
For Peripheral Equipment
MISCELLANEOUS
A Control Room /Studio
Communications System
The Band's "Last Waltz"
1977 Grammy -Winning
Engineers and Producers
Microcomputers /Microprocessors
December, 1978
Bill Isenberg
9 -6
December, 1978
Peter Butt
Chris Foreman
John G. McKnight
9 -5
October, 1978
April, 1978
February, 1978
Richard Factor
Paul C. Buff
9 -1
9-2
9-1
9-1
Don Pearson
and Tom Lubin
9-6
Ray Kimber
Deane Jensen
Ken Fause
February, 1978
February, 1978
9 -5
9 -3
December, 1978
October, 1978
June, 1978
9-3
June, 1978
Stan King
and Bob Marich
9-5
October, 1978
Chris Foreman
9 -2
April, 1978
Talmadge Ball
Jeffry Dahl
John Robinson
9-5
October, 1978
February, 1978
Kitty Puckett checks out 45 rpm stamper. white
auditioning one at 334's rpm
The Nashville Record Production Inc., uses
Stanton exclusively throughout its two Disc
Cutting Studios. Naturally, they are mostly involved with Country Music, but they also get
into Pop and Rock.
John Eberle states that they use the Stanton
Calibrated 681A for cutting system calibration, including level and frequency response"
... and they use the Calibrated 681 Triple -E in
their Disc Cutting operation .. with plans to
soon move up to the new Professional Calibration Standard, Stanton's 881S.
Each Stanton 681 series and 881S cartridge, is guaranteed to meet its specifications
within exacting limits, and each one boasts the
most meaningful warranty... an individually
calibrated test result is packed with each unit.
Whether your usage involves recording,
broadcasting, or home entertainment, your
choice should be the choice of the Profession als...the Stanton Calibrated Cartridge.
© Stanton 1978
J.
Mastering Tape Compatibility
SIGNAL PROCESSING
Small and Miniature
Reverberation Chambers
Michael Nemo
Nashville, the Center
of Country Music, is
Stanton Country, too!
9 -1
Bill Szymczyk
Howard Cummings
9 -4
9 -4
August, 1978
August, 1978
R -e /p
9-4
August, 1978
Staff
EXPANDED
CONTACT AREA
Michael Rettinger
9 -4
August, 1978
R -e /p
R -e /p
9-6
9-3
9-3
9-2
December, 1978
June, 1978
June, 1978
Andrew Berliner
9-2
April, 1978
Richard Factor
9-1
February, 1978
Bob Todrank
Gary Carrelli
Ed Lever
9 -3
9 -4
June, 1978
R -e /p
9-2
April, 1978
February, 1978
Staff
Staff
In Use R -e /p Staff
R -e /p Staff
Staff
Jack Wiener
9 -1
April, 1978
Scanning Electron Beam Microscope photo of Stereo
hedron" stylus. 2000 times magnification. brackets point
out wider contact area
-
For further information write: Stanton Magnetics,
Terminal Drive, Plainview, N.Y. 11803
August, 1978
STANTON!
R-c/p 101
www.americanradiohistory.com
Passive
Direct Box
Active Direct
Boa
SYNTHESIZER PATCH
CHART COLLECTION AVAILABLE
SM -2
Delon Active
Single
Direct Box
'Mic -splitten"
d
MS-1A
SM-3
Quad
"Mic-splitter"
8x2 "Mie-oplitter"
MS-8
MS-4
12 x 2
"Mic-splitter"
16x2 "MIo-splitter"
sMS-10
MS-9
Direct Boxes: Both active and passive SM -1A for
guitars SM -2 and SM -3 f r keyboards and
electronic instruments.
"Mic- splitters ": Low im edance
^a ^Cie
-
6 dOrn
in and out.
Will
Will pass phantom voltage.
Thouiondi to vie around We World!
also manufacture audio transformers.
snakes. audio modules
We
SEND FOR YOUR FREE COPY
OF OUR NEW CATALOG
P.O. Box 590,
12931 Budlong Ave.,
Gardena, CA 90247 U.S.A.
5E5
COM
Ouahty
Engineered
(213) 770-3510. (800) 421-1828, Sound
Products"
`TWX (910) 346 -7023
0
0
0
Q
0
0
0
-
Said to be the largest collection of music
synthesizer patch charts ever assembled in
one volume, The Source is available from
Polyphony at a cost of $4.00, postpaid.
To allow adaptation to a wide variety of
models of synthesizers, all of the patch
charts are shown in block diagram/flow
chart type of notation. The variety of types
of patches included can serve the synthesist
directly, or through inspiration in aiding the
musician to develop original patches.
-
1")
One inch minimum, payable in advance. Four inches maximum. Space
over four inches will be charged for
at regular display advertising rates.
(21/4" x
BOOKS
POLYPHONY
P.O. BOX 20305
OKLAHOMA CITY, OK 73156
(405) 842 -5480
theory and working
information and emphasis on
practical uses
-
"MICROPHONES
HOW
THEY WORK AND HOW
TO USE THEM'
-
TAPE EDITING
BOOK AVAILABLE
by Martin Cldloro
224 Pages
97 Illustrations
58.95 Hardbound; $5.95 Paperback
Joel Tall, the inventor of modern tape
splicing blocks, probably knows as much or
more than anybody about the art of splicing
audio and video tapes. Now he has written a
book, "Tape Editing," which not only
explains the basics of tape splicing and
editing, but gives a flock of helpful hints that
can benefit both novice and professional
tape editors. One intriguing trick, for
example, is running the tape backwards.
Listening in reverse helps the editor to more
sharply recognize certain speech sounds.
The 32 -page tape editing "bible" will be
sold through retail stores handling tape
equipment. "Tape Editing" carries
0 0
0 0
0 0
a 0 0
0 0
Pt 0
0
0 0
Q 0
CLASSIFIED ADVERTISING
RATES
$45.00 Per Column Inch
Postpaid
R -e/p Books
P. O. Boa 2449
Hollywood, CA 90028
SOUND RECORDING
John Eargle. JME Associates
"The best book on the technical
side of recording
thoroughly
recommended "
Studio Sound
338 Pages. illustrated with 232 tables,
by
-
curves, schematic diagrams, photographs,
and cutaway views of equipment.
516 95
R
P. O.
each
-e/p Books
Box 2449
Hollywood. CA 90028
SOUND SYSTEM ENGINEERING
a
by Don 8 Carolyn Davis
suggested retail price of $2.00.
296 Pages
ELPA MARKETING INDUSTRIES
THORENS & ATLANTIC AVENUES
NEW HYDE PARK, NY 11040
When you subscribe to
-
8' /axil
Hardbound
$19.95
R-e/p Books
P. O.
Box 2449
Hollywood. CA 90028
R -e /p
you'll be starting a useful reference library pertaining
to the recording industry.
.
.
.
We will be delighted to enter your subscription to R -e /p upon receipt of
your order and payment (check or money order must be included with
-
we cannot bill for subscriptions). Your subscription will
your order
begin with the next published issue. (Sorry! We cannot start with back
issues.)
Foreign subscriptions are payable in U.S. funds only and must be by
bank check or money order.
Please provide the information below and mail with your payment to:
Recording Engineer /Producer, P.O. Box 2449, Hollywood, California
90028. Since R -e /p is published six times per year, please allow ample
time to receive your first issue.
ONE YEAR (SIX ISSUES)
United States (surface mail)
United States (air mail)
All Other Countries
Orders processed same day
COD's accepted
Write for free catalog and price list, with
full information on other assorted
goodies in little black boxes.
o
v
ö
I
have enclosed
Name
Stat,on,Company
iTa
Windt Audio Inc.
1207 N. Western Ave.
Los Angeles, CA 90029
(213) 466-1271
$10.00
$17.00
S19.00
S
Title
Li New
Address
City
R-e/p 102
www.americanradiohistory.com
Renewal
Home
State /province/Country
Zip
Office
FOR SALE: MCI - 24 -track with 16track heads. Well maintained work
HANDBOOK OF
MULTICHANNEL
RECORDING
horse. Reasonable.
Call M. GUTHRIE
(212) 581 -6505
by F. A /ton Everest
320 pages - 201 illustrations
The book that covers it all ...
a comprehensive guide to all facets of
multi.:rack recording ... acoustics ...
construction ... studio design
equipment .. techniques ... and
much, much more.
Hardbound $10.95 - Paperback $7.95
N\
AUDIO OP -AMP'S
Standard 7 Pin Pkg.
Highest Professional
...
R -e /p
Quality
SLowest Possible Price
fPROTECH AUDIO
PO.BOX 638
Books
P.O. Box 2449 Hollywood, CA 90028
CONSULTING SERVICES
Consulting in Performance and Presentation Technology
ENTERTA NMENT SOUND SYSTEMS
STEMS
:iiiil
TIME DELAY SPECTROMETRY
ASSIIfL:IIPS
1887 Tipperary Lane
AUDIO.VISUAL SYSTEMS
Newbury Park
CA
91320
18051498.4006
EQUIPMENT FOR SALE
FREE
TRACKS!
Total recording systems, specializing in the
semi -pro studio. Tascam, TEAC, Neotek,
BGW, dbx, MicMix, Sennheiser, TAPCO.
MXR, Shure, S.A.E.. and many others.
COMPLETE STUDIO PACKAGES
CATALOG & AUDIO APPLICATIONS
CONSOLES
KITS L WIRED
AMPLIFIERS
MIC, 60 ACN,LINE
1
For the very best Studio
TRACKS
9520
47th Street
Brookfield, IL 60513
(312) 485 -0020
Construction and Design
available
81
NO
AS
POWER SUPPLIES
I.ABI IN(
for additional information circle no. 87
guilty of constructing the following
studios
Types 104aB and 105
Reference Series
for classical
Sound Interchange,
Toronto, Canada, new
studio
monitoring.
-
Superscope, San Fernando,
California. new studio
!vie
Chicago Recording Company,
Chicago, Illinois, Studios 1,
2 and 3
Electronics
Bill Szymczyk's Bayshore
Recording Studios, Inc.,
Coconut Grove, Florida,
production
fe
OV
Portable Audio Test Equipment
new studio
The Shade Tree
(205) 871 -4221
FOR SALE: MCI JH- 114i24 24 -track
master recorder, MCI Auto Locator
for 24 -track recorder, MCI JH -428
master console 24x24 and producer's
desk. Contact Chgo.
(312) 785- 3838/9
The EXR EXCITER will do more for
your recordings than outboard EQ
could ever do. If you don't agree,
we'll buy it back. We also have
Marshall, Lexicon, Eventide, Delta Lab and Loft. Call us.
AS1 Pro Audio
(512) 824 -8781
CONCERT SOUND /LIGHTING
SYSTEM: Portable with road cases,
major auditorium capabilities. Retail
value $123,000. Will consider reasonable offers. Call (816) 531 -4305 or
(816) 361 -9114.
:
Century 21, Winnipeg,
Canada, new studio
ONE STOP FOR ALL YOUR
PROFESSIONAL AUDIO REQUIREMENTS
BOTTOM LINE ORIENTED
F. T. C. BREWER COMPANY
P.O. Box 8057 Pensacola, Florida 32506
FOR SALE
Neumann 24- channel recording console;
3M Series 56 16 -track machine; 2 - 3M
Series 56 2 -track machines; Allison Research 24- channel Memory's Little Helper
computerized mixing; 5 - dbx 187 units
(4 channel per unit). A perfect 16-track
studio set -up.
Package price $40,000.00.
For more information and individual
prices, call Tom
BULL!!!
He pleads
C422
run side -by -side.
We have our opinions.
Call Wes. Ron or Dick.
C -24 vs.
1033 N. SYCAMORE AVE.
LOS ANGELES, CA. 90038
(213) 934 -3566
OPAN11'
...
He is also known for
doing work all over North
America, giving firm
estimates, exacting dates
of completion and ...
CROWN CX -844
Four channel with trac /sync, remote,
balanced, anvil case, two years old,
but new condition. $2,000.00 firm.
Senor Sound, Inc.
(412) 921 -7744
TAPE, DISC, POWER
OSCILLATORS
AUDIO, TAPE
'
AVAILABLE
ARCHITECTURAL
`4,
CO.
LAKE RONKONKOMA.NY 11779
R EVO^
SERVICE
&
MODIFICATION
TO PROFESSIONAL STANDARDS
15 IpS B -77s in
Playboy Club
i
Lake Geneva, Wisconsin
new studio
Group Four, Hollywood, Calif.
KBK Earth City Studios
stock'
St. Louis. Missouri
CLEAN USED EQUIPMENT
Village Recorders,
Neve BCM 10 2 mixing desk, pair of AKG
C -60 tube microphones. Balantine 310
ACVTVMs. HP412AR, Interstate F -44
Sweep- Marker function generator, recommended by Don Davis for TDS work.
ReVox A -77 Mark IV. Dolby. 15 ips. 2-
Los Angeles, California
new studio
track
Ronnie Milsap,
Nashville, Tennessee
Want an EMT 140 type sound without
the drawbacks? The new ECOPLATE
is studio proven in L.A. Great reverb
at a good price'
12
Record Plant,
Los Angeles. California
new studio
new studio
Call for information and details
RUDOLF A. BREUER
798-9127
85
ARROYO ANNI
NNF X
Pasadena, CA 91109
AUDIO ENGINEERING ASSOCIATES
C
"
805 / 273-3792
Lic. No. 23831',
R-e/p 103
www.americanradiohistory.com
EQUIPMENT FOR SALE
Two DATA -MIX Consoles for sale. Excellent condition. Now in use. Both are 24track and wired for 36-input and 36output. Complete with modules. Many
gold and platinum albums made on these
consoles. Original price, $96,000.00;
asking price, $15,000.00.
Call Hal Selby
Electric Lady
(212) 477 -7500
MAGNETIC TAPE
BEST NAMES IN TAPE
AT THE BEST PRICES
AGFA
Dept REP
1038 Northern Blvd
Roslyn. NY 11576
FOR SALE
LIKE NEW HARRISON 3232 RECORDING CONSOLE WITH 26 1/O
MODULES. SPARE POWER SUPPLY. PRODUCER'S DESK, AND
EXTRA PATCH BAY. S61,000.00.
CALL CHICAGO RECORDING
COMPANY, (312) 822-9333. ASK
FOR CLEON WELLS, OR ALAN
KUBICKA.
condition. Original cost $70,000.00.
(205) 871 -7328
AMPEX
3M- SCOTCH
-
Tascam. TEA C, Scund Workshop. ()tad
dbx, Nakamlchi, MXR, Dynaco. ADS, E -V,
Eventide, Shure. Maxell, Ampex, AKG Pro,
Beyer. UREI, Sfax. Sennhelser, TAPCO,
Crown. and more!
SEND FOR PRICE QUOTES
ZIMET PRO AUDIO
FOR SALE
Mobile 16 Track Studio. Completely customized Chevalier 16' van, fully equipped
with brand name gear. In service. Inspection by appointment. Three years old, mint
call toll free
800 -531 -7392
ABROON SUN,INC.
P
0 Box 6520. San Antonio. Texas 78209
FOR SALE
MCI JH- 114 -24 24 -track with auto
locator and flux track; $23,900.00.
EQUIPMENT WANTED
WANTED
RECORDING EQUIPMENT
OF ALL AGES AND
VARIETIES
Dan Alexander 6026 Bernhard
Richmond, CA 94805 U.S.A.
(415) 232 -7933 or (415) 232 -7818
SOUND 80
(612) 721 -6341
* RECORDING STUDIO *
For Sale! Newly remodeled and equipped
plush Early American decor with video
and 24 -track capability. Located in
booming Orange County. Motivated
owners.
C & I PROPERTIES
(213) 598 -6852 (714) 894 -3377
EMPLOYMENT
EDUCATION
Short intensive summer courses in recording techniques, electronics, electronic,
jazz improvisation, contemporary song writing, popular and jazz harmony, musical instrument repair and instrumental
workshops in saxophone, clarinet, flute,
trombone, and percussion, with Allard,
Oberbrunner, Rascher, Goebel, Purcell
and Strohman. Write or call Frank
Stachow, Summer Workshops. (717)
867 -4411, ext. 275.
LEBANON VALLEY COLLEGE
Annville, PA 17003
WE ARE
LOOKING FOR
THE
TWO BEST
DISC MASTERING
ENGINEERS
WE
WAKEFIELD MFG., INC.,
Phoenix, Arizona
85005
Phone
P.O. Box
CAN FIND
6037
REAL ESTATE
L.A. BROKER
Specializes in Business Opsïlocations for
studios. Former background in mixing
and recording. Let us help you sell your
studio business or expand it to new
location. PLEASE CONTACT:
BRUCE LOWELL
HELEN ROWE and ASSOCIATES
(213) 934 -8444
602- 252 -5644
OPPORTUNITIES
- Toronto -
FIELD ENGINEERS
New York
Los Angeles
Rupert Neve, Incorporated, the world leader in professional sound
consoles and computer assisted mixing systems, is seeking qualified
technical personnel to fill one or more Field /Service Engineer
position(s) in New York, Toronto and Los Angeles. Our technical
staff work with the most sophisticated audio equipment, including
Neve consoles, NECAM minicomputers and Lyrec studio recorders.
We offer excellent salary according to experience and ability; liberal
vacation, holiday and fringe benefits, and the opportunity to work with
a true industry leader. Relocation expenses paid. If you would like to
join a dynamic and successful company in rapid growth, please
forward your resume in confidence, or call (203) 744 -6230.
Mr. Barry Roche
Executive Vice President
Rupert Neve, Incorporated
Berkshire Industrial Park
Bethel, CT 06801
ESTABLISHED MIDWEST
RECORDING STUDIO
seeks business investor. Excellent profit potential. Call (515) 972 -4924 or write:
Box FDI, c/o R -e /p
P.O. Box 2449
Hollywood, CA 90028
EMPLOYMENT
WANTED
Experienced disk mastering engineer to
operate a Neumann Lathe and associated
equipment. Tech /maintenance capabilities desired. Contact:
I.
A. M.
17422 Murphy Avenue
Irvine. CA 92714 (714) 751 -2015
MAINTENANCE ENGINEER
/s/ Neve
www.americanradiohistory.com
Top San Francisco studio has open-
ing for qualified maintenance engineer. Send resume and specify salary
requirements to:
Box DSF, c/o R -e /p
P.O. Box 2449
Hollywood. CA 90028
audible changes in real life.
For the record, a spot check of three
manufacturers of speakers and/or amplifiers in the Los Angeles area supported the
formula used. The formula, by the way, is
not one I made up, but rather one which is
commonly used by the industry.
Mr. Dickensheets has supplied us with a
summation of his position and, since the
letter is on Boner & Associates letterhead, I
can assume also the position of Boner &
Associates on the importance of wire size
for speaker runs. Mr. Dickensheets word
for -word summation is as follows:
Until the damping factor of an
amplifier reaches a value below 20:1,
this damping factor does not have a
significant effect on the actual
damping factor of the amplifier /speaker combination and until the
resistance of the wire approaches a
value of several ohms, it too has little
effect on the actual damping factor of
the circuit.
According to his viewpoint, as long as an
amplifier has an output impedance of .4
ohms or less, it does not have a significant
effect on damping factor. The .4 ohm figure
is reached by dividing 8 by 20. This means
that virtually all currently- manufactured
amplifiers meet this level of acceptability.
Mr. Dickensheets then states that you
SUPERVISING ENGINEER
BONNEVILLE PRODUCTIONS has an
immediate opening for an electronic engineer to supervise technical operations
of our tape duplication operation. Qualifications necessary include a BSEE (or
equivalent training plus experience), thorough experience in magnetic tape theory
and recording techniques (professional
systems), an excellent troubleshooting
background and the ability to supervise
a staff of four engineers and technicians.
Experience with Cetec /Gauss tape duplication equipment is preferred. Tape production and engineering areas are designated no- smoking. Please reply with
resume, references and salary requirements to:
Lorna van Komen
Bonneville Productions
130 Social Hall Avenue
Salt Lake City, Utah 84111
Give
Heart'
Market expansion has created a new
position for a take -charge individual with
solid experience in sound contracting
and or consulting. The person we seek
will have outstanding verbal and written
communication skills and will be able
to work with architects, consultants. contractors and their clients. He she will have
responsibility for IBL and UREI professional sales through sound contractors
in all parts of Canada.The winning candidate will be based in Montreal and will
travel as required to support his 'her
dealers. English 'French bilingual fluency
is not required but is desirable.
-
i
I
Fund
American Heart Association
1
-LETTERSRay Kimber's reply continued from
page 16 ..
.
fully realize that the formula which used
also has some error in it. But stand firm that
the degree of change in the result of the
formula I used approximates perceived
I
PROFESSIONAL
AUDIO SALES
MANAGER
1
1
Send resume (including salary history):
H.Z. GOLDSTEIN
GOULD MARKETING CO., LTD.
109 MONTEE DE LIESSE
ST. LAURENT, QUEBEC H4T 159
CANADA
CREED( BACK
/ij¡fi¡ï/ï¡i/í`¡igjïllii¡i¡iiiiii1iii1i01i`I- \1\1\\-'
á. f
AIL
lt.
ti
ti!_ t.
¡-
1
1_
I-1-
4 4444r.4 .l_1.t.f.l.f.1_1.1_I.1
d j11i1%1i
/WI
tti.i.i
1
1-
11I.ili
lii.i.11:'
ANNOUNCING
A HARRISON COMPROMISE
Sorry competition,. .. price only.
Affordable automation is now even more affordable.
The Harrison 3624 and 2824 are now available at 10% off
for a limited time. Not a quality cutback, but a price rollback
so you can put some of the long GREEN... BACK in your pocket.
HARRISON SYSTEMS, INC.
P O.
Box 22964, Nashville, Tennessee 37202
www.americanradiohistory.com
Almost
NO COMPROMISE
Harrisonpl
(615) 834 -1184. TELEX 555133
Outside it's
BLACK
Inside
it's
ßL\
LJ3
a
TYPE 85 FET DIRECT 80X
INST.
AMP.
PICKUP
Ct-c)
SPEAKER
may then couple speaker wire approaching
"a value of several ohms with little effect."
We find by looking at a wire resistance chart
that 100 feet round trip of number 22 gauge
is approximately 2.7 ohms. I find it difficult;
no, impossible, to believe that Mr.
Dickensheets and/or Boner & Associates
can't hear a difference between 100 feet of
number 22 gauge and 100 feet of a much
heavier gauge using just about any
amplifier /speaker combination he pleases.
Let me conclude with a little warning for
all. 'The natural scatter of data in the mental
world exceeds the number and nature of
differences we are able to perceive in the
physical world." (pace Petrov contra
Lorenzo)
MIC OUTPUT
OPEN
}
f
INDESTRUCTIBLE
EXTRUDED HOUSING
RECESSED
CONNECTORS AND
SWITCHES
BATTERY OR PHANTOM
POWERED
INTERNAL PAD FOR
SPEAKER BRIDGING
CLARENCE C. MOORE
AUDIO PIONEER AND
INNOVATOR PASSES
Clarence C. Moore, founder and
of Crown International, Inc.,
passed away on January 24, 1979, at the age
of 74.
Mr. Moore's primary impact in the field of
audio was the development of the first tape
president
recorder which included a power amplifier,
the invention of the cubical quad antenna
system, the creation of the first I/ -inch 4channel recorder and the introduction of
the first solid state power amplifier.
Though Clarence Moore's formal educa-
tion included a bachelor's degree from
Marion College with majors in English,
chemistry and music and graduate study at
the University of Notre Dame in clinical
psychology, he never stopped his drive for
additional knowledge. His life was characterized by a strong religious faith, a striving
to improve himself and the desire to be of
utmost use to his friends and his God.
AKG ESTABLISHES
WESTERN SERVICE CENTER
AKG Acoustics has recently established
center for AKG microphones and
reverb units at 3940 Higuera Street,
a service
Culver City, California 90230, in the Los
Angeles area.
West Coast consumers are advised to
send their AKG units to the address above
for repair. Twenty -four hour turn -around
time is normal for most units.
The phone number is (213) 204 -1952.
BRUNO HOCHSTRASSER NAMED
PRESIDENT OF STUDER
REVOX AMERICA, INC.
Effective in January, 1979, as announced
by Willi Studer, Mr. Bruno Hochstrasser will
be responsible for all U.S.A. activities of
both the Studer line of professional tape
recorders and associated equipment, and
the ReVox brand of audiophile components. A ten -year veteran at Studer, he was
previously vice -president of sales for Studer
International in Regensdorf. No stranger to
the North American market, he served as
vice -president of Studer Re Vox of Canada,
Limited, for four years until his return to the
home office in 1977.
TRUE GROUND
ISOLATION -EVEN
WHEN PHANTOM
POWERED
R.F. FILTERED ON INPUT
AND OUTPUT
ACTIVE CIRCUIT -DOES
NOT LOAD PICKUPS
11110E111111
-
II:IIIIIIIIIL9I11Í1I
LESS THAN 2uV NOISE
RESPONSE
TO 20 KHz
.5dB 20 Hz
.050Io HARMONIC
DISTORTION
COUNTRYMAN ASSOCIATES
424 Stanford Avenue
Redwood City, CA 94063
Phone (415) 364 -9988
"OK', so I accidently erased your lead vocal, but NOW
we've got an open track for AUTOMATION!"
www.americanradiohistory.com
Mr. Hochstrasser will be based in
Nashville, and will be assisted in sales and
engineering support activities by Tom
Jenny and Heinz Schiess. Jenny comes
from field sales in Switzerland and
previously held engineering and sales
positions with Studer in South Africa and
Switzerland. Schiess previously served
Studer in both sales and engineering
positions in France, Switzerland and
Canada. Also reporting to Mr. Hochstrasser will be Rob Robinson, newly appointed
Re Vox sales manager.
BOOK REVIEW
AUDIO IC OP -AMP
APPLICATIONS
by Walter G. Jung
Price: $7.95, 208 pages
Publisher: Howard W. Sams & Co., Inc.
The application of the new IC operational
amplifier to the field of audio signal processing has been slow to develop. One reason for
this is the fact that the problems the audio
designer encounters when he attempts to
incorporate IC op -amps in his circuits have
been insufficiently treated in technical books
and papers. This book examines the various
pitfalls in detail and discusses methods for
realizing the full potential of the op -amp in a
I
wide variety of audio circuits.
The book is organized into six chapters.
Chapter 1 introduces and briefly discusses
the IC op -amp types under consideration,
and covers general operating procedures
and precautions to be observed in using the
various devices. Chapter 2 discusses IC opamp parameters that are important in audio
applications, while Chapter 3 deals with the
basic op -amp configurations as they are
applied to audio use.
Chapter 4 covers a wide variety of
practical audio amplifier circuits in which
specific IC types are used. Equalized
amplifiers and active filters are dealt with in
Chapter 5, while Chapter 6 discusses a
miscellaneous assortment of special purpose audio circuits. The appendixes contain
a data sheet on the Signetics 5534 op -amp
and a list of manufacturers' names and
addresses and the audio IC op -amps that
they manufacture.
Readers already familiar with basic opamp theory will find this book a valuable
addition to their technical libraries.
Reviewed by Peter Butt
AUDIO IC OP -AMP
APPLICATIONS
P.O. Box 2449
Include
BOOKS
Hollywood, CA 90028
Minimum Transient Distortion
Low Noise
Years of transformer manufacturing and design experience, combined with computer
assisted technology, have enabled us to make a significantly
audible improvement in the
performance of audio transformers.
(Visitors by appointment only.)
$7.95 each
money order or check with your
Wide Bandwidth
Write or call for information
1617 NORTH FULLER AVENUE
HOLLYWOOD, CA 90046
(2131 876 -0059
May be ordered directly from
R -e/p
JensenEtrá nsförmers
order.
know this sounds impossible...
but want the intro from the second mix,
pull up the horns in the turn -around from the last mix,
fade the background vocals at "B" like the third mix,
and give me the number one mix on the electric piano at the bridge...
I
-
HARRISON SYSTEMS, INC.
i11ww..r.nsr+arrr...ow.....r.....
P O. Box 22964, Nashville, Tennessee 37202
www.americanradiohistory.com
(615) 834 -1184, TELEX 555133
v
ö
VCA's
... continued
from page 87:
.2.
,-415434
INpUT
ß4
tI
IMD
I
MP
-4°
CAW
...
FIG .13..
r{Fax,TE6a IM15 V. GAIN ca+m4HJ
..
FIGURE
t
. :
1
IMPROVEI) dBx/MC.I CONT-IGL12ATlOk)
F14
Ip
.MEASuYED.INö
:iii
......
:-
........
t
O+ISd$v
GAiU
.........
t IodsY
--
tHD
M.._
--Yt:L6tA
SJU$ri
.
#4ca.
........
....
I67PQTP
..VCA-SM
-4
IA
_.. _..._
:::
...
4sdeCods Od$......_7s
---
òd$v
:,a---'.4411
:.-
--4
"'-'-Fl L 1G.
-MiSv.
S
.LñIr.
alas.,
_714v11T
atz 4s6dE+
SAE
=
usn
r===
aC--+Jw+
FIGURE
IKHt
12.
ALLISON / MCI CONFIGURATION
1141)
61.1a
--Ad1M
19
:
Adl..
-v1
FIG IS
VSINa
úT6ElQ JNMGrIN
vewsRa
CKZ
ú
pJ.
t
assessment of the advantages and disadvantages of the
three voltage controlled devices mentioned herein. will try
to do so in a subjective and unbiased manner.
I
structure requires a +28 dBv output, the 2002 Op -Amp is reconfigured to raise the output (and noise) of the VCA -5M to
provide this elevated output level.
In properly employing the VCA -5M, the value of the input
resistor is adjusted to cause the maximum signal deliverable
by the preceeding stage to coincide with the VCA's input
clipping point. The control voltage is offset to accommodate
the range produced by the console, and to optimize the
dynamic range of the circuit. Please refer again to Figures 6,
7 and 8 for the noise and distortion contours produced by this
circuit.
It should be noted that in both the dbx and Allison
configurations, up to 20 dB of additional reserve gain is
available, over and above that gain range provided by this
particular console. On the bottom end, another 10to 20 dB of
shutoff is also available. The B & B deployment, conversely,
is pushed to the limits of its gain control range, and is
operating in a region of serious scale factor non -linearity.
DBX 202
The dbx 202 is a true VCA, capable of a gain control range
in excess of +30 dB to -100 dB. It offers excellent scale factor
linearity, control rejection, noise levels and distortion levels.
Its operating parameters are user definable. Perhaps the
biggest problem with the 202 is a lack of understanding, on
the part of its users, on the selection of proper operating
parameters. There are compromises in the selection of input
current and output coupling methods, which may have a
profound bearing on the distortion and noise parameters.
When these parameters are properly defined, there is no
excuse for serious audio degradation in most applications.
Thus defined, the device has valuable application in all
situations requiring a true VCA.
B & B 1537A
VCA, but rather, a VCATT, or voltage
controlled attenuator. As such, it offers excellent noise,
distortion and temperature immunity. It exhibits a good scale
factor linearity over the range of -20 dB to -80 dB gain, and it
has a maximum gain control range of 0 dB to -100 dB. By
careful employment of temperature compensated nonlinear corrective circuitry, its scale factor linearity could be
The device is not
CONFIRMING MEASUREMENTS
While making the measurements on the B & B VCATT,
also did a series of side-by -side measurements (using a
Sound Technology) on two randomly chosen production
VCA -5M modules. In making the B & B measurements,
compensated for the 6 dB input gain by stating the input
levels 6 dB higher on the graphs than what had used in
making the tests. Thus, both devices were measured and
charted with the same relative input levels. The results of the
B & B vs. the worst of the two VCA -5Ms are shown in the
graphs of Figures 13 through 18.
I
I
I
improved.
Thus defined, the device should find application where
Voltage Controlled Attenuation is required, but its usefulness is limited in most applications requiring a wide range,
true VCA.
SUMMARY
In
closing this paper,
I
a
ALLISON VCA -5A and VCA -5M
would like to present my personal
The VCA -5A and M are two derivatives of the same basic
R-c/p 110
www.americanradiohistory.com
1\.
'
,-.
-
`,,1,,/,///%%/Ì/%/Ì///1///%/i/iIIIIiIIIiIII!IIIIII'I":\`\\`\\\\
f,f,f.f_t.ff .fr
ff r rr r r
0)( pt t.,.p
r- r- r- r- r- r-
r.
rr
r. i- 1- r.
1
1-
1-1-
.!r..
1.1-1-1
.
r. .
1;\
'
-
.
.
.
-
\
7
NO
COMPROMISE
Two nice sounding words, just like a lot of other
nice sounding words that manufacturers and suppliers use to describe their products and services.
Talk is cheap and so are words, so in order for
words to have any true value they must stand for
something of value.
At Harrison Systems No Compromise means
something very real to us, to our dealers, and to
our customers. No Compromise is a way of doing
business, a philosophy that we believe in, a standard by which we can measure our every decision
and endeavor, not just pretty words.
The No Compromise philosophy is with us
every minute of every day. It is the dominant
factor in the design, the manufacture, and the
after sales support of every piece of equipment
that we build.
To our dealers it means that they are representing and delivering the very best recording
consoles available in the world. They are proud
of the fact and we are proud of them. Without
exception Harrison dealers world wide are the
finest, most knowledgeable, most honorable audio
professionals to be found.
Harrison customers have the No Compromise
philosophy, also. In most cases the decision to
purchase a Harrison console has not been made
on price, for there are many consoles that sell for
less. Harrison owners know that they have purchased the finest consoles for their studios. That
goes a long way toward the making of a No Compromise studio. Interestingly, most Harrison
owners have found that the choice of a Harrison
console has in the long -run been the most
profitable for their operations. The care and
expertise in the design of the consoles have made
their clientele very happy and supportive. The
quality of construction and check out have meant
minimum down time and start up problems.
Harrison consoles have a history of very good
retained value which means that the cost of
ownership can be quite reasonable.
Many years ago one of the smartest men I
have known told me that if you take care of
business, then business will take care of you.
Taking care of business...I guess that is what
Vo Compromise is really all about. /)
a
Harrison
HARRISON SYSTEMS. INC.
P O.
Box 22964. Nashville. Tennessee 37202
www.americanradiohistory.com
(615) 834 -1184. TELEX 555133
circuit. The 5M is a minimum size VCA module featuring
current inputs for the audio and control circuits, and a
voltage output. It has all necessary operating circuitry inbuilt, with the exception of the current establishing audio
and control input resistors.
The VCA -5A is a card frame mounting device which
features differential voltage inputs for the audio and control
circuits. It has a voltage output, and requires no external
parts.
The devices are true VCAs, and employ an all npn
monolithic gain control element, in a balanced differential
arrangement under current application to the U.S. Patent
Office. Of particular importance to the design, is the
proprietary employment of trimmable compensating loops,
which cancel the inherent error of log /antilog elements at
the higher operating currents. The result is a very low
production of distortion products, under all conditions of
signal level and gain control.
The devices are accurate over a gain control range in
excess of +35 dB to -105 dB, and feature excellent
parameters of noise, distortion, temperature immunity,
scale factor linearity and control circuit rejection.
The design has one inherent difficulty which manifests
itself in the form of a gently rising high frequency THD
characteristic. (See Figure 19) It should be noted that the
production of harmonics is still quite low at 10 kHz, being
typically under .15 %, and that harmonics produced for
frequencies above 10 kHz are of little concern since they are
out of the range of normal hearing. One must differentiate
between the gentle distortions shown in Figure 19 and the
severe distortion often produced by slew rate induced
triangulation of some modern circuits in the 20 kHz to 50 kHz
region. The latter forms of distortion can be audible since the
spurious products rapidly exceed 20% once triangulation
begins.
20
150kHz
and Out
bsence of
e
t
pd distortion
150kHz, Full power Bandwidth
20vp -p in and out
Figure 21:
Spectrum analysis of
VCA -5M
Input =lOkHz at OdBv
Equipment -Tektronics 5L4N
1.0%
ì20oio
Harris
Figure 22:
Residual products of
VCA -5M
Input =20kHz at OdBv.
Equipment Sound Technology 1710A
with 80kHz filter in.
911
Op -Amp
VCA 5M
0.5%
THD =.16%
THD
0%
100Hz
5
1k
5
2
10k 20k
50 100kHz
Frequency
impressed on the control signal input. This is particularly
true at high frequencies where the chance of capacitive
coupling between the two ports is increased. Always ground
any unused control voltage inputs. (Do not ground current
mode inputs.) Keep impedances low, and observe every
precaution to isolate the control port from interference.
Figure 19
Gentle Rise in THD vs Frequency VCA -5M
vs
Slew Induced THD for Harris 911 Op -Amp
The VCA -5A and M exhibit an excellent slew rate of 13
volts /µsec, and can deliver, or accept, full power signals at
frequencies in excess of 150 kHz, as indicated by the scope
photo of Figure 20.
PRECAUTIONS FOR ALL VCAS
must always be remembered that any VCA or VCATT is a
multiplier, and is capable of producing severe distortion, or
modulation, if any audio signal is allowed to become
It
CLOSING
The use of Voltage Controlled Elements, not to mention
Digitally Controlled Elements, offers important advances to
the art of audio control. As with any relatively new science,
however, the successful employment of such devices must
be accompanied by a keen understanding of the principles
involved, the limitations, and the engineering disciplines
required to make the implementation truly effective and
beheficial.
It is the responsibility of the creators of these new
techniques to educate the users, and to make certain that the
product offered truly advances the art, rather than merely
serving as a means to enrich the manufacturers bank
account, at the ultimate expense of the consumer and the
industry.
R-e/p 112
www.americanradiohistory.com
COME
i
::::
,.'ar-;:
i ¡,,
l(lI
fmf¢¢ic1m'mm1¢mmmc¢1almm
¡:1111
i
I
I'I,I,III,I,I
I I I
1111
Now, a high performance studio quality Harrison
console designed for LIVE PERFORMANCE. The
Harrison NO COMPROMISE philosophy has been
carried through every aspect in the design of the
ALIVE console. Standard features:
Harrison transformerless microphone
preamplifiers.
Automated VCA Faders with Groupers.
8 VCA matrix sub groups.
3 band parametric EQ with high -pass.
HARRISON SYSTEMS, INC.
;
,=
:
1
i-i-i-i i'i-i
.:
I
I
I
I
I
I
I
.
.
I,,1 ,I,I\`'`1
.
.
.
,1
!
Direct communications interface.
4 main stereo output pairs.
8 auxiliary send busses.
built -in 16 segment electronic LED VU meters.
32 or 24 channel mainframes and extender
frames.
3 point overload LED indicator on each I/O
module.
Road proof lightweight aircraft aluminum frame.
8
P.O. Box 22964, Nashville, Tennessee 37202
(615) 834 -1184, TELEX 555133
1 fact:
I you can choose your
microphone to enhance
your productions.
Shure makes microphones for every imaginable use.
Like musical instruments, each different type of Shure microphone has a
distinctive "sound," or physical characteristic that optimizes it for
particular applications, voices, or effects.
Take, for example, the Shure SM58 and SM59 microphones:
SM59
Mellow, smooth,
silent...
The SM59 is a relatively new,
dynamic cardioid microphone. Yet
it is already widely accepted as a
standard for distinguished studio
productions. In fact, you'll often
see it on TV ... especially on musical shows where perfection of
sound quality is a major consideration. This revolutionary cardioid
microphone has an exceptionally
flat frequency response and neutral sound that reproduces exactly what it
hears. Its designed to give good bass
response when miking at a distance. Remarkably rugged
it's built to shrug off
rough handling. And, it is superb in rejecting mechanical stand noise such as floor
and desk vibrations because of a unique,
patented built -in shock mount. It also features a special hum -bucking coil for
superior noise reduction!
-
Some like it essentially flat...
_
.
.
.
__
.
...
.
.
.
--.,.-. j
-
1:1:.
I
Crisp, bright
"abuse proof"
Probably the most widely used
on- stage, hand -held cardioid
dynamic microphone. The
SM58 dynamic microphone is
preferred for its punch in live
vocal applications ... especially where close -up miking is
important. It is THE world standard professional stage microphone with the distinctive Shure
upper mid -range presence peak for
an intelligible, lively sound. World renowned for its ability to withstand
the kind of abuse that would destroy
many other microphones. Designed
to minimize the boominess you'd expect from close miking. Rugged, efficient spherical windscreen eliminates
pops. Lightweight (15 ounces!)
hand -sized. The first choice among
rock, pop, R & B, country, gospel.
and jazz vocalists.
...some like a "presence" peak.
.
i
il
SM58
}f
i-
.
7
rREOUFHCN
rREOUERCY
N
HERTZ
inERrz
professional microphones...by
ri
Shure Brothers Inc., 222 Hartrey Ave., Evanston, IL 60204, In Canada: A. C. Simmonds & Son Limited
Manufacturers of high fidelity components, microphones, sound systems and related circuitry.
for additional information circle no.
91
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertising