Discrete Microcompressor Midside ttt





Compact VC compressor with midside or stereo or dual mono processing for eurorack modular synthesizers. 24HP.




  • Discrete Blacksea VCA based feed-forward compressor.
  • Completely discrete circuit - VCAs and level detectors are discrete.
  • Three main modes selectable by switch - Midside, Stereo, Dual mono.
  • Sidechain filter. LP, HP, filter off - selectable by switch.
  • Adjustable by potentiometers Treshold, Ratio, Attack, Release, Makeup gain, Filter cutoff frequency..
  • Treshold, Makeup, Ratio, Filter cutoff, Attack and Release can be controlled by CV.
  • 5 LEDs reduction indicators range 40dB.
  • Two attack/release modes are available -- auto and variable. In AUTO mode attack and release rates are linked to shortest times possible (attack is 0.1ms). In VAR mode independent adjustments of the attack and release dynamics are possible.
  • Peak (fast) or RMS (slow) detector timing options.
  • Sidechain in for external sidechain processing.
  • Envelope out allows to patch any VCA as compressor.
  • Bypass switch.
  • MIX knob adds input signal to the output - for parallel compression.
  • Full reverse polarity protection.
  • Power consumption: V+ 165mA, V- 176mA


For better understanding here is a page with plots from simulation stage http://l-1.su/Discrete_Microcompressor.html


Modulargrid: https://www.modulargrid.net/e/l-1-midside-discrete-microcompressor




Paypal: info(at)greenexpo.by


Assembled module $550 + $20 shipping.




Compressor has 3 main modes - Midside, Stereo, Dual Mono.


  1. Midside. When compressor is in Midside mode. Then input stereo signal processes through midside coder. Left side of the module controls Mid part. Right side of the module controls Side part. At the output a signal converts back to stereo through midside decoder. More about midside processing read here https://www.soundonsound.com/sound-advice/q-how-does-mid-sides-recording-actually-work

  3. Stereo. When compressor is in Stereo mode. Then equal amount of compression applies to both chennels. To achieve that, both channels are summed after level detectors and then process through only left sidechain. So left side of the module controls both channels. Right side of the module is not active (but LED indicator work anyway).

  5. Dual Mono. When compressor is in Dual Mono mode. Then left and right sides of the module work as two independend mono compressors.



Sidechain filter.


  • Sidechain filter locates at sidechain input, and filters coming audio signal. That allows the compressor to react only to filtered frequencies. For example, in Midside mode, the compressor can compress only basses in the middle and only trebles at the sides.

  • The filter has LP and HP modes. Filter's slope is 6dB/oct.
















(c) L-1 Synhesizer. E-mail: info@greenexpo.by