A simple 3HP module with audio VCA (in stereo) and trigger input. The 1:1 looped stereo audio signal is attenuated by the VCA with a curve triggered by the trigger. The curve can be adjusted with two controls for intensity and shape length. This makes it easy to achieve ducking effects.

If no cable is plugged into the audio input, the 0.5V control voltage of the curve comes out of the output on the right. This can be reused with external modules if required. The front panel is printed differently on both sides for a 180-degree installation.