OK, so this 2HP expander works with the voltage controlled ADSR module I made based around Electric Druid’s well known ENVGEN8 chip.
To keep the original module to 6HP, I didn’t include the TIME parameter (which extends or contracts the whole ADSR envelope) under voltage control or a panel mounted pot, and I didn’t have a bipolar +/-5v output for the looping ADSR/LFO function.

This just adds those two features: TIME is now a potentiometer and a CV input with attenuator responding to +/-5v, and there is a 0-5v to +/-5v bipolar converter (that does the exact opposite of my Unipolar converter module). That way the module is more useful if you’re using it as an LFO.

Aaaand off it goes to be fabricated. Files etc to be uploaded once I’ve built and tested it.
Update August 2023
Tested and working. Build files and gerbers are here. Licence CC BY-NC-SA 4.0.
