LA Audio BCL2 User manual

PRO-SERIES
BCL2
OPERATION MANUAL

BCL2 1
CONTENTS
1. Introduction 2
2. Specifications 3
3. Installation 5
4. Description of the controls 6
5. Applications 8
6. Technical description 14
7. Maintenance 16
Appendices:
Circuit Diagrams
PCB Diagrams
Outiline and dimensional drawings

BCL2 2
1. INTRODUCTION
The BCL2 Is a stereo compressor-limiter with a de-essing capability which allows the
professionnal user to process two different signals of one stereo program.
Applications include : FM transmitter protection, disc mastering, SPL limiting In PA
and discotheque applications, tightening of drums and sustain control on guitars and
bass.
Main parameters, Including threshold, gain, attack and release times and
compression ratio are user controllable.
A unique feature of the BCL2 is the continuously variable detection characteristics. A
potentiometer allows mixing of RMS and Peak detectors to tailor the timing
parameters to the program being processed. The BCL2 takes advantage of a unique
transformer distortion cancelling scheme reducing it an order of magnitude compared
to conventional designs.
2 bargraphs control the compression amount and the input/output level. The de-
essing functions Involves a slew-rate sensitive network which, keeping operation very
simple, allows frequency-conscious compression, In accordance with FM
transmission or disc mastering pre-emphasis.
A rear panel jack allows insertion of an external equalizer to achieve more specific
frequency-conscious processing.
RFI protection has been a main concern in the design of the BCL2 allowing its use in
broadcast installations.
A ground lift switch allows the elimination of hum loops.

BCL2 3
2. SPECIFICATIONS
2.1. ELECTRICAL
Frequency Response
20 Hz to 20 kHz +0, -0.25 dB
Signal to Noise Ratio
+ 4 dBu Input, + 4 dBu Output 94 dB
Input Impedance 20 kOhms balanced
Output Source Impedance 20 Ohms
Output Load Impedance 600 Ohms to infinity
Maximum Input Level + 20 dBu
Maximum output Level
600 Ohms Load, 1 kHz 20 dBu
Total Harmonic Distortion (THD)
+ 4 dBu Output,
1 kHz, 10 dB compression 0.07 %
1 kHz, by-pass 0.01 %
Intermodulatlon Distortion 0.01 %
Compression Ratio
Continously variable from 2 : 1 to 20 : 1
Attack Time (Peak)
Continously variable from 0.1 to 70 millisec.
Release Time (Peak)
Continously variable from 100 millisec to 3 sec.
Attack Time (RMS)
Program dependant Typ. 12 ms for 12 dB
Typ. 4 ms for 24 dB.
Release Time (RMS)
Program dependant Typ. 120 ms for 12 dB
Typ. 240 ms for 24 dB
Mains power
Consumption 6 Volts-amps
(115/220 VAC, 50-60 Hz)
Meter Calibration 0 Vu = + 4 dBu
Maximum Gain Reduction more than 50 dB
DS Action ** 12 dB at 8 kHz

BCL2 4
2. SPECIFICATIONS
2.2. PHYSICAL
Input Connector XLR/QG 3 pin balanced
Output Connector XLR/QG 3 Pin balanced
Dimensions 483mm W x 190mm D x 44.5mm H
19"W x 7.5"D x 1.75”H
Weight 3.9 kg, 8.6 lbs
Shipping Weight 4.8 kg, 10.6 lbs
Temperature Range
Operating 0oC to +50oC
Storage -30oC to +75oC
Finish Light Grey epoxy
Note : In these specifications, 0 dBu is referenced to 0.775 V RMS.
* SMPTE Method : 60 Hz + 7 kHz mixed 4:1, + 20 dBu output.
** DS action Is defined as the Increase of compression at the specified
frequency, referenced to compression at 1 kHz.
Product Information and specifications are subject to change without notice.