There’s a fellow with a website here that documents a clever idea for building LFOs and ADSRs using PIC microcontrollers rather than the usual handful of analog components. I’m quite sure that this would be a less expensive way to build these modules, and one could build exotic things like DX7-style rate/level EGs instead of plain-vanilla ADSRs. He even provides his source code for the firmware. I might build the ADSR on a breadboard just to see how it performs. (Personally I prefer AVR chips to PICs, but hey, if all I have to do is assemble somone else’s code and burn it, I’m not gonna complain about his choice in CPUs.)
Nifty PIC-Based Synthesizer Modules
