AJH Synth-Minimod VCA (Black)

Discrete dual transistor VCA that recreates the early Minimoog gain structure, from clean control to musical overdrive.

The MiniMod VCA Black is a faithful recreation of the cascaded dual VCA design used in the earliest Minimoogs. Just like the original, two transistor VCAs sit in series. This structure shapes not only level, but tone and response.

You can treat the first stage as a tone shaper and the second as a master output VCA. Engage the internal high gain mode on the first VCA and it begins to overdrive in a very specific way. The clipping emphasises odd harmonics more than even ones, giving it an amp like edge that works well on basses and leads. The amount of saturation depends on both input levels and CV control, so you can patch dynamic distortion rather than fixed grit.

Two audio inputs with attenuators feed the first VCA. This makes it easy to balance oscillators before they hit the gain stage. Driving them harder increases density and compression before the signal even reaches the master stage.

CV inputs 1 and 2 plus an offset control shape the first VCA. The second stage has its own Master CV input and level control. If no CV is patched to the master input, the knob simply sets output volume. Once you introduce a control voltage, it becomes an attenuator. The master CV input is sensitive and responds well to hot envelopes or LFOs if you want stronger dynamics.

The response is linear, as in the original design. For natural sounding amplitude shaping, it pairs best with exponential envelopes such as a Minimoog style contour generator. Used this way, it behaves like a complete vintage gain section inside your Eurorack system.

This module suits anyone building a full MiniMod voice, but it also stands alone as a character VCA that can move from clean level control to driven transistor colour.