Synthesizer - Envelope module
This is an ADSR-style envelope module. It’s dual channel with the knobs controlling both channels.
To my knowledge this circuit is a unique approach to the problem. It uses an LM13700 as a slew-rate-limited buffer and a cheap analog latch.
Source files including code and CAD are available on GitHub. Like most everything I do, this is open hardware.
This module is still a work-in-progress. The design has been confirmed on a breadboard, but the PCB still needs to be designed.