TUBE-TECH CL 1B User Manual

LYDKRAFT ApS
Mose Allé 20, DK 2610 Rødovre
Denmark
1
Owners manual
TUBE-TECH
CL 1B Compressor
DESCRIPTION.
The TUBE-TECH compressor CL 1B differs from many other compressors, in that the gain-
reduction element is made from a non-semiconductor element, which in itself has a very low
harmonic distortion and none of the non-linearity problems involved when using most
semiconductor elements. Furthermore there is no long-term degradation of the element thus
giving it almost infinite life. This element is placed after the input-transformer of the compressor
and followed by an all tube-based amplifier with a gain of - dB to +30 dB.
Thus the signal is not fed through any semiconductor circuitry on its way to the output.
The amplifier consists of two tubes (valves) in push-pull configuration (one ECC 83 as the
pre-amp and phase splitter, and one ECC 82 as the output stage), and an output transformer.
The power supply for the pre-amp and phase splitter are stabilized and the heaters of both tubes
(valves) are fed with a stabilized DC voltage.
The whole amplifier (including input and output transformer) and the power supplies are placed
on one PC-board.
Both input and output are balanced (600) and fully floating.
The in/out key switches the compressor in and out without clicks.
THE SIDECHAIN:
The side chain is the only part of the compressor that contains semiconductors. They are used
for three reasons: First they do not affect the sound reproduction, second they have a high slew
rate, which is of importance for the performance of the compressor and third they don't take up
much room.
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 attack and release times
2. Variable attack and release times
The attack/release select switch makes it possible to use these two circuits separately or
combine their functions.
This gives a feature not normally obtained in other compressors:
In the combined (fix. /man.) state the attack- and release controls make it possible to
obtain a complex release-time slope. (See page 4)
(140919 jgp)

TUBE-TECH CL 1B Specifications

General

Maximum Output Level	+26 dBu
CMRR @ 10 kHz	> 60 dB
Type	Opto Compressor
Output Impedance	60 Ohms
Attack Time	0.5 ms to 300 ms
Release Time	50 ms to 10 s
Power Requirements	115 V or 230 V (factory wired)
THD @ 0 dBu	< 0.05 %
THD @ +10 dBu	<0.5%
Tubes	1 x ECC83, 1 x ECC81

Summary

Description of the Tube-Tech CL 1B Compressor

The Sidechain

Explains the side chain's role, semiconductor usage, and components within the compressor.

Compressor Interconnection

Controls

Gain Control

Explains the gain control for makeup gain, its range, and placement after the gain-reduction circuit.

Ratio Control

Describes the ratio control's function in varying the compression ratio and its continuous variable range.

Threshold Control

Defines the threshold as the point gain reduction begins, detailing its continuously variable range.

Meter

Details the VU-meter switch positions: Input, Compression, and Output for monitoring levels.

In/Out Switch

Explains the leverswitch for bypassing the compressor in/out of the signal path.

Attack Control

Describes the attack control's function in determining compressor response speed and its variable range.

Release Control

Describes the release control's function in determining response speed to signal decrease and its variable range.

Attack/Release Select

Bus Select

Explains how to interconnect multiple compressors using bus selection for synchronized operation.

Suggested Applications

Overall Compression

Provides recommended settings for final mix overall compression.

Standard Compression

Offers settings for standard compression on various instruments and vocals.

Heavy Compression on Instruments

Gives settings for heavy compression on line guitar and piano.

Compression of Drums

Provides settings for snare and bass drum compression.

Adjustment Procedure

Caution

Advises on unit heat-up duration and offset-voltage checks before adjustments.

Adjustment of Basic Gain

Details the steps for calibrating the basic gain of the unit.

Adjustment of Compression Tracking

Outlines the procedure for accurately adjusting the compression tracking.

Adjustment of the VU Meter Reading "Compression"

Adjustment of the Release Control

Explains how to set the release control for a specific time measurement using the VU meter.