Module is available as a DIY project only.
This Module is currently available.
dual processor
SPC stands for "super-processor"; it is a really useful voltage processor - an updated take on a well known design.
It can be used to for adding, inverting and mixing control voltages.
With the link switch, the output of the bottom circuit become the 4th input of the top processor.
The extra "Inverted SUM" output is taken from before the offset processor.