The VCAs circuit design is based on an advanced version of the famous “blackmer gain cell” by the THAT Corporation.
The module is available in two versions: with either DC- or AC-coupled inputstage.
DC coupling allows modulation of control voltages and very low frequencies. While AC coupling can remove offsets in waveforms such as the one of the DIV/N output.

The module features a potentiometer for manual gain control. A second potentiometer to adjust the amount of CV1. CV2 is a direct control voltage input for gain control which is not attenuated.

The circuit is set to -110dB Gain with gain potentiometer set to zero and no external CV applied.
Sensitivity of the CV inputs is set to 95mV/dB.

The circuit processes voltages up to 20Vpp without clipping! Voltages over 20Vpp get hard clipped.


  • Signal IN
  • CV1 Input (adjustable amount)
  • CV2 Input (fixed amount)


  • Signal OUT


  • +12V 4mA / -12V 4mA


  • Width: 6 TE (30.1mm)
  • Depth: 13mm