User Manual

ManualsBrandsTube Tech ManualsAudio accessoriesCL 2A Dual Opto Compressor

LYDKRAFT ApS

Mose Allé 20, DK 2610 Rødovre

Denmark



TUBE-TECH CL 2A

dual compressor

DESCRIPTION.

The TUBE-TECH compressor CL 2A is a dual opto compressor with a gai n reduction

element, which have no long-term degradation and almost infinite life. Th is element are

placed afte r the inp ut-tran sformers of the compressors and follo wed by an all t ube-based

amplifier with a gain of -



dB to +10 dB.

Thus the signal is not fed through any semiconductor circuitry on its way to t he output.

The amplifier is based on two tubes (dual triodes) in push-pul l co nfiguration (one ECC 83 as

adifferentialamplifier,andoneECC82astheoutputstage), and an output transformer.

The power supply for the differe ntial amplifie rs i s stabilised and the heaters of all four tubes

are f ed with a stabilised DC voltage.

The two amplifiers (including input and output transfo rmer) and the p ower supplies are

placed on one PC-board.

Both input and output are bal anced and fully float ing.

The compressors are switched i n and out via two relays (click less).

THE SIDECHAIN:

The two side cha ins are the only part of the compressor that contains semiconductors.

It contains two J-FET quad op-amps, one npn-transistor and one FET-transistor, which

handles the signal for the gain-reduction element.

The compressor contains two time constants circuits:

1. Fixed a ttack and release times

2. Vari able attack and release times

COMPRESSOR INTERCONNECTION:

The side chain sockets fo r interconnection of several compressors are locate d on the rear

panel.

A swi tch on the front selects which compressors are interconnected, and on which bus the y

are connected. If you e.g. have 10 compressors in a rack, you can select compressor 1,5,7

and 8 on link 1, and compressor 2,3,6 and 9 on link 2, leaving compressor 4 and 6 in the off

position.

Compressor 1,5,7,8 is now interconnected and all four will perform the exact same

compression. This applies to compressor 2,3 ,6 and 9 as well. Compressor 4 and 6 are

independent.

(150203)

Summary of content (7 pages)

PAGE 1
TUBE-TECH CL 2A dual compressor DESCRIPTION. The TUBE-TECH compressor CL 2A is a dual opto compressor with a gain reduction element, which have no long-term degradation and almost infinite life. This element are placed after the input-transformers of the compressors and followed by an all tube-based amplifier with a gain of - dB to +10 dB. Thus the signal is not fed through any semiconductor circuitry on its way to the output.
PAGE 2
The interconnection implies, that the unit that performs the most compression is controlling the others. To choose which one you want to control, select the attack/release time, the threshold and the ratio on that unit, and turn the threshold fully counter clockwise on the remaining compressors. It is of course possible to have all the interconnected compressors control each other simultaneously. NB: Remember to set the ratio-control and the gain-control in the same position on the "slaves".
PAGE 3
NB: Leave the meter switch in position compression as it might introduce distortion if left in output position. IN/OUT: Switches the compressor in and out of the signal path. In the out position the entire compressor is bypassed. ATTACK: The attack control chooses how fast/slow the compressor responds to an increase in the input signal. The attack control is continuously variable from 1 to 60 milliseconds.
PAGE 4
SUGGESTED APPLICATIONS OF TUBE-TECH COMPRESSOR CL 2A In the following, you will find suggestions on various applications of the TUBE-TECH compressor CL 2A. They are given as a convenient guide to enable you to familiarise yourself with the different aspects of using the compressor. We have not mentioned specific settings of gain and threshold as they are dependent upon input levels. Instead we have specified how much compression in dB, we feel, is needed for the various examples.
PAGE 5
ADJUSTMENT PROCEDURE: CAUTION: Before making any adjustment let the unit heat-up at least 15 min. Observe that the offset-voltage measured at the sidechain jack socket, when the THRESHOLD is off, is not greater than +/- 15 mV DC in both position "fixed" and "manual". (tip is link 1 and ring is link 2). If the voltage exceeds this value, replace either IC1 or IC2. THE GRE (GR1) SHALL BE MARKED FROM 1.005 TO 1.
PAGE 6
ADJUSTMENT OF THE VU METER READING "COMPRESSION": 1) Turn the THRESHOLD-control fully counter-clockwise. 2) Switch the METER-selector to Compression. 3) Set the RATIO-control at 1,5:1 4) Apply a signal of 1 kHz, 0,0 dBU into the input of the compressor. 5) Adjust the GAIN-control to an output-reading of 0,0 dBU. 6) Adjust P 8 until the meter is reading 0 VU. 7) Apply a DC-voltage of +250,0 mV into the sidechain jack socket and observe that the output level has dropped to -10,0 dBU.
PAGE 7
TECHNICAL SPECIFICATIONS CL 2A: Input impedance: Output impedance: 5 KOhms < 60 Ohms Frequency-response @ -3dB: 5 Hz to 40 kHz Distortion THD @40 Hz: 0 dBU: 10 dBU: maximum output (1 % THD): maximum input (1 % THD): Noise Rg=200 Ohm: Output Gain Unweighted CCIR 468-3 < 0,15 % < 0,15 % +26,0 dBU +21,0 dBU 0 dB -80,0 dBU -70,0 dBU +10 dB -80,0 dBU -60,0 dBU Cross talk @ 10KHz < -60dB CMRR @ 10KHz < -60dB Gain: off to +10 dB Compressor Ratio: Threshold: Attack: Release: 1,5:1 to 10:1 off to -20 d