This compact 2HP module has two switches which connect to the gain jumpers on the VCA and VCF.

Switch “up” is the same as having the gain jumper in place, switch “down” is the same as removing the jumper, and gives higher gain. Using these switches gives a similar effect to the old "headphone out to external input" trick on the original Model D but with a much wider overdrive range, particularly from the VCA. We have also included a six way passive multi.