cosmotronic/messor

Messor

Cosmotronic

Stereo compressor and transient shaper with VCA-based feed-forward design, switchable HP/LP sidechain filter, CV inputs for attack, release, filter cutoff and makeup gain, and Stereo VCA mode.830

Capabilities 3

Stereo Compressorstereo-compressor
VCA-based feed-forward stereo compressor with sidechain filter, envelope follower, CV inputs for attack, release, filter cutoff and makeup gain.830
Stereo VCAstereo-vca
Set Make Up Gain knob to MUTE and patch an envelope to the GAIN CV input to use Messor as a stereo VCA.830
Transient Shapertransient-shaper
Ratio can exceed limiting into over-compression to completely reshape transients.830

Jacks 10 (7 in / 3 out)

NameSignalVoltageDescription
Inputs (7)
ATTACK CV INcv0V to 5VCV input for attack time modulation. Useful range 0–5V; Attack knob acts as offset.830
EXTERNAL SC INaudioExternal sidechain input. Normalised to a mono mix of the left and right channels. Patching breaks the internal sidechain connection allowing external signals (e.g. a kick drum) to drive the gain reduction.830
GAIN CV INcv0V to 5VModulates the output/makeup gain level. The Make Up Gain knob acts as an offset. Set knob to MUTE and patch an envelope here to use Messor as a stereo VCA.830
LEFT INaudioLeft channel audio input. Normalised to the Right input when nothing is patched into it.830
RELEASE CV INcv0V to 5VCV input for release time modulation. Useful range 0–5V; Release knob acts as offset. Negative CV can push the release time below 5ms.830
RIGHT INaudioRight channel audio input.830
SC FILTER CUTOFF CV INcvCV input to modulate the sidechain filter cutoff frequency.830
Outputs (3)
LEFT OUTaudio830
RIGHT OUTaudio830
SC ENVELOPE OUTPUTcvOutputs the sidechain gain reduction envelope. Available independent of Ratio and Bypass switch settings.830

Parameters 9

NameTypeRangeBehavior
AttackknobSets the time the compressor takes to start reducing output volume, controlling how much of the initial transient is preserved. Longer settings average overall dynamics and affect high frequency handling. Longer attack times also extend the release.830
Bypass Switchswitch830
Lowpass/Highpass Selectswitch830
Make Up GainknobApplies gain to the signal after compression to match output to input level. With knob set to MUTE and an envelope patched to the GAIN CV input, Messor operates as a stereo VCA. The knob acts as an offset when CV is applied. Nominal CV values are 0-5v.830
Ratioknob830
Zones
Off
Limiting
  • Off -100–-100%Compressor is disabled.830
  • Limiting 0–100%830
Releaseknob5ms – 3500msSets the time for the compressor to stop reducing gain after the input signal drops below the threshold. Longer times create an averaging effect. Very short release times can cause distortion in low frequencies. Negative CV can push the release time below 5ms.830
Side-chain Filter CutoffknobSets the cutoff frequency of the 6dB switchable LP/HP filter in the sidechain path. Certain frequencies can trigger gain reduction while others leave the signal unchanged. Can be set to cut off all frequencies, resulting in no compression.830
ThresholdknobSets the signal level where compression begins. Signals below threshold are unaffected; signals above generate the sidechain. Gain reduction envelope is visualised by orange LEDs under the knob. Setting threshold lower creates more gain reduction. Expects modular levels (-10 to 17dBv).830
Warm Saturation SwitchswitchSelects between Pure and Warm modes. In Warm mode, an analog tube saturation emulator increasingly soft-clips the signal as headroom limits approach, while leaving lower-level signals intact. Adds compression and warmth. A small side effect is a slightly lower output volume. Pure mode disables this effect.830

Firmware history 0 versions

No firmware history recorded.

References 2

  1. [830]
    Cosmotronic Messor Manualmanual
    verified 2026-05-23
  2. [831]
    Cosmotronic Messor product pageproduct_page
    verified 2026-05-23