It features exactly the same tube circuit as our famous CL 1B Opto Compressor, but the action is different due to a different, carefully selected optical element and a fine-tuning of the control circuit.

This provides the CM 1A with an attack that enhances transients in a more punchy way, making it ideal for percussive material, yet still very well suited for vocals, bass guitar, etc.

The different optical element does NOT seriously change the the "classic" characteristics, known from the CL1B.

The action of the CM1A places it somewhere between the LCA2B (Tube VCA) and the classic CL1B.
CM1A has been extremely well received by numerous top engineers.

Note: Due to the high quality of the TUBE-TECH RM Series power supply and the pristine audio circuits, the Modular Series products deliver exactly the same uncompromised sound quality as our 19" units.

The TUBE-TECH CM 1A Compressor features a gain-reduction element, positioned immediately after the input transformer.

It is controlled by the sidechain amplifier, which also contain the two time control circuits - one for fixed and one for variable Attack/Release. The two time-controllers can either be used separately or combined.

This circuit contains semiconductor OP-amps for the entire control.

A tube-based push-pull amplifier follows the gain-reduction element with variable gain up to 30 dB. A dedicated Bus selector with three positions (Off, Link 1, Link 2) is used whenever you want to link several compressors together. Input and output transformers have a static-screen between the primary and secondary wirings. Input and Output is transformer balanced as well as fully floating.

Unique, low-distortion optical gain reduction element

All-tube based push-pull amplifier

Frequency response @ -3 dB: 5 Hz to 25 kHz

Low noise: < -75 dBU @ 30 dB gain

CMRR: > 60 dB @ 10 kHz

Variable ratio from 2:1 to 10:1

Continuously variable attack and release times

Variable threshold: Off to -30 dBU

Output gain: Off to +30 dBU

Input impedance: 600

Interconnection of several compressors via two busses

LED display for monitoring compression and output

Conductive plastic potentiometers

Gold plated switches

Input and output are transformer balanced and fully floating