Gerber data, schematic and BOM for the Envelope follower module PCB used in making the opto compressor.
The envelope follower circuit can function as a modular synth module on its own, but it also has its uses in compressor, wah, level meter, etc.
Video
https://www.youtube.com/watch?v=21ZDvu3n3l0
Document
https://note.com/solder_state/n/n60c27ec32764