Orban 464A User manual

Operating Manual
The Co-Operator
Gated Leveler/Compressor/High-Frequency Limiter/Peak Clipper
Model 464A

IMPORTANT NOTE: Refer to the unit’s rear panel for your Model Number.
Model Number: Description:
464A/U
464A/E CO-OPERATOR Level Control System, 2ch 115V CO-OPERATOR Level Control System, 2ch 230V
OPTIONS:
Model Number: Description:
SCI Security Cover (CLEAR, BLUE, or WHITE)
CAUTION: TO REDUCE THE RISK OF ELECTRICAL SHOCK, DO NOT REMOVE COVER {OR BACK).
NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL.
WARNING lTO REDUCE THE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS
APPLIANCE TO RAIN OR MOISTURE.
This symbol, wherever it appears,
alerts you to the presence of uninsulated
dangerous voltage inside the enclosure —voltage
that may be sufficient to constitute arisk of shock.
This symbol, wherever it appears,
alerts you to important operating and
maintenance instructions in the accompanying
literature. Read the manual.

Operating Manual
The Co-Operator
Gated Leveler/Compressor/High-Frequency Umiter/Peak Clipper
Model 464A

Co-Operator is atrademark and Orban is aregistered trademark of AKG Acoustics, Inc.
Dolby is aregistered trademark of Dolby Laboratories, Inc.
This Orban product has been manufactured by AKG Acoustics, Inc.
This manual is part number 95059-000-03
300 -FB -1/93
©Copyright 1993 by AKG Acoustics, Inc.
1525 Alvarado Street, San Leandro, CA 94577 USA
Telephone [phone]
Fax [phone]
orban
adivision of AKG Acoustics, Inc.

Orban 464A
The Co-Operator
Operating Manual
page contents
1-
iSection 1: Introduction
Orban's Co-Operator
Applications
Registration, Warranty, Feedback
2
-
1Section 2: Installation
Installation and Set-up
Level-matching
3-
1Section 3: Operation
Controls and Meters
Recommended Control Settings
More About Co-Operator Audio Processing
4
-
1Section 4: Maintenance
Routine Maintenance
Getting Inside the Chassis
Performance Evaluation
5-
iSection 5: Troubleshooting
Problems and Possible Causes
Technical Support, Factory Service
6-
iSection 6: Technical Data
Specifications
Circuit Description
Parts List, Schematics, Assembly Drawings
Abbreviations
INDEX on next page

index
abbreviations 6-26
accessories 2-13, 6-2
applications 1-4
assembly drawings 6-20
audible distortion 3-8, 5-3
audio
connections 2-5
input 2-5
output 2-5
tape recorder 3-4, 3-1
0
audio/video production 1-4
automatic gain control (AGC) 3-8
average modulation, increasing 2-10
balanced inputs 2-7
balanced output transformer 2-7,8
bargraph driver 6-9, 6-12
bi-amped systems 1-4, 3-7
block diagram 6-21
buzzes 5-2
cable shielding 2-5, 2-7
cassette duplication 1-4, 3-6
chassis, getting inside 4-2
chassis ground 2-7
circuit boards
access to 4-2
front panel 4-2
circuit description 6-4
circuit ground 2-7
clicks 5-2
clipper-defeat jumper 2-2, 2-9
clipping 2-10, 3-10
bias 2-10,3-4,5-3,6-10
increasing 2-1 0, 5-3
level calibration 2-1
1
transient 3-8
common-mode rejection 2-7
component
numbering system 6-4
vendors 6-19
compression 3-8, 6-8
connectors, audio 2-5
constant-directivity horns 1-4
controls 3-2
control settings 3-4
BetaCam/MII VCR 3-5
broadcast cart machine 3-5
broadcast transmission 2-12,3-4
cassette duplication 3-6
FM subcarriers 2-12, 3-6
Quad VTR 3-5
satellite uplink 3-5
sound system protection 3-7
STL protection 2-12, 3-4
type BVTR 3-5
type CVTR 3-5
U-Matic VCR 3-6
covers, removing/replacing 4-2
customer service 5-3
dBu (definition) 4-5, 6-26
de-essing 3-9
distortion 3-8, 5-3, 6-6
dual mode 3-10
factory service 5-4
FM subcarrier generators 1-5
protection 2-9
front panel 1-2, 3-2
fuse 2-4, 6-2
gain reduction 3-8
meter 3-8, 6-8
gating 3-8, 5-2, 6-8
control circuits 4-3
grounding 2-6,7, 5-2
difficult situations 2-8
ground loop 2-7,8
harshness 5-2
high-frequency
limiter 3-9,4-3,6-10
pre-emphasis 3-9
saturation 1-4
high-SPL environments 1-4
hum 5-2
impedance 2-5
input
attenuator 3-8, 6-5
balanced 2-7
buffer 6-5
impedance 2-5
level 2-5, 6-8
stages 4-3
overload point 2-5
unbalanced 2-8
installation 2-1
FM broadcast 2-9
jumpers
access to 4-2
positions 2-3
leveling 3-8, 6-8
loudness 3-4, 3-8
maintenance, routine 4-2
meters 3-2, 4-3, 6-8, 6-1
1
calibration 2-10, 2-14, 6-11
red zone 3-8
nastinesses, various 3-8
noise rush-up, pumping 3-8, 5-2
options 2-13, 6-2
ordering parts 6-13
output
impedance 2-5
level 2-5
matching to toad 2-1
4
stages 4-3
unbalanced toad 2-5
overheating, thermal failure 1-4
overshoot 5-2
packing for shipment 5-4
parts list 6-13
peak
clippers 5-2
control 5-2, 6-10
level 3-8
overload point of toad 2-15
analog tape recorders 2-15
audio power amplifiers 2-15
USA-standard phone lines 2-15
output level meter 6-1
1
calibration 2-10, 2-14
performance evaluation 4-3
phone jacks 2-5
physical dimensions 6-2
power
cord 2-4
requirements 6-2
supplies 4-3, 5-2, 6-12
pre-emphasis 3-9,10,5-2,6-10
jumper 2-2, 2-9
LF/HF drivers 3-10
problems 5-2
product features 1-3
rack-mounting unit 2-4
rear panel 1-2
recording studios 1-4
registration card 1-6
regulated voltage 6-1
2
regulator dropout 6-12
release shape 3-8,9, 6-8
release time 3-8, 6-8
retrofit kit 6-2
return authorization 5-4
RF suppression 5-2, 6-5
ringing 5-2
SCA channels 1-5
schematics 6-20
security cover 2-13, 6-2
service 5-4
shipping
damage 2-2
instructions 5-4
shrillness 5-2
sound systems 1-4, 3-7
specifications 6-2
stereo mode 3-10
STL protection 1-5, 2-9
swept sine wave tests 3-10, 6-1
0
tape 3-1
0
technical support 5-3
thumps 6-6
tilt 5-2
timing module 6-8
transmitter
pre-emphasis 2-9
protection 2-9
troubleshooting 5-1
unbalanced input 2-8
unbalanced load 2-5
unregulated voltage 6-12
user feedback 1-6
VCAs 4-3, 6-6
voltage regulators 5-2, 6-12
warranty 1-6
XLR connectors 2-5

page contents
1-3 The Orban Co-Operator
1-2 Fig. 1-1: Front and Rear Panels
i-4 Applications
i-6 Registration, Warranty, Feedback

in
CAUTION
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Orban
Model
464A

Co-Operator INTRODUCTION 1-3
The Orban Co-Operator
The Orban Model 464A Co-Operator™ Leveler/Compressor/HF Limiter is an inte-
grated automatic gain control (AGC) device of the highest professional quality. The
Co-Operator is afriendly, automatic “assistant operator” that smoothly and unobtru-
sively rides gain, controls high-frequency levels, and limits peaks.
The Co-Operator achieves its outstandingly transparent audio performance through
the use of finely-tuned control loops which eliminate the dynamic distortions that are
the downfall of most conventional compressors and limiters, and through the use of
aclean, class-Aproprietary VCAto ensure negligible static distortion and noise.
•Asmooth leveler function provides transparent gain riding —without long-
term distortion-producing overshoots.
•Afaster “compression” function can be switched in to provide additional
transient overshoot protection for material with abrupt level changes or un-
usually high peak-to-average ratios. The compression function is available
without leveling for applications that require safety limiting only.
•Release time and release shape are adjustable to optimize processing for
music or voice.
•Adefeatable “silence gate” prevents noise rush-up, holes, pumping, and
breathing by inhibiting sudden gain increases once the signal level falls below
apreset threshold (during pauses or low-level program material).
•Six switchable HF limiter pre-emphasis/de-emphasis curves (25 to 150|is)
allow the HF limiting to react optimally for the medium or device being
protected and guard against excessive sibilance.
•Adefeatable clipper follows the HF limiter for absolute peak protection.
•Either stereo-tracking or independent two-channel operation can be selected.
•The least-used controls are concealed behind asecurity panel to avoid con-
fusing non-technical operators, and to permit tamper-proof calibration.
•Two LED bargraphs per channel simultaneously display gain reduction and
peak output levels.
•Output level meter can be calibrated to match the overload point of the device
being drivea
•Balanced, floating inputs and outputs are EMI-suppressed; the Co-Operator
is compatible with the levels and impedances found in both professional and
semi-professional applications.
•25dB gain reduction range is achieved with alow-distortion, class-A VCA.
•Two channels packaged in aspace-saving, rugged, all-metal, 1%-inch chassis.
•Hard-wired bypass switch is included.
\

INTRODUCTION Orban Model 464A
Applications
The flexibility and natural sound of the Co-Operator are ideally suited to recording
studio, sound reinforcement, broadcast, motion picture, and video sound applications.
The defeatable high-frequency limiter can be used to prevent pre-emphasized mate-
rial from overloading tape recorders, disk cutters, high-frequency drivers in sound
systems, broadcast STLs (studio-transmitter links), FM SCAs (“subsidiary commu-
nications authorization”), and for controlling cassette masters which have excessive
high-frequency energy. Controlling high-frequency energy permits average recording
or transmission levels to be increased, yielding improved signal-to-noise ratios.
Recording Studios
With the RELEASE SHAPE control set to SOFT, the Co-Operator will subtly reduce the
dynamic range of an entire mix. The HARD setting provides effective gain riding on
single tracks, increasing “punch” and intelligibility while retaining the basic feel of
the performance and the apparent dynamic range of the voice or instrument. The
RELEASE TIME control is useful in governing the uniformity of loudness in the final
result.
Audio and Video Production
The Co-Operator can be used to protect VTRs, ATRs, or cart machines from overload
during transfer. On mic channels the Co-Operator’s smoothness and silence-gating
guarantee uniform, punchy voice quality without noise rush-up during pauses.
Cassette Duplication
Even with the latest advancements, such as “hot” tape and Dolby® HX Pro, there
are still some masters which can cause high-frequency saturation in cassette dupes.
The Co-Operator’s high-frequency limiter can be set to eliminate problems caused by
synthesizers, cymbals, and sibilance, while still permitting high average modulation
on the cassette. The broadband AGCAeveler can be defeated to permit use of the HF
limiter alone when automatic gain riding or broadband peak protection is not desired.
Sound Systems
The Co-Operator provides colorless protection for your system —whether it be a
fixed installation or traveling PA. For example, in an unattended bi-amped system,
the slow AGC leveler can efficiently ride gain while the faster compressor protects
the system from abrupt increases in level.
Placed after the mixer and equalizer and before an active two-way crossover, the
Co-Operator will protect power amps from excessive clipping and high-frequency
drivers from thermal overload.
Especially with constant-directivity horns, the selectable pre-emphasis of the HF
Limiter can protect the horn from the boost that is required to compensate for the
constant-power high-end roll-off. When horns and drivers are located 75 feet in the