So, I received the last three prototype PCBs; Voltage Follower, Ring Modulator, and Input Amp. When these have been checked out, I'll order a small production run and will call the modular part of this done!
I'm working with the Duo Phonic keyboard right now. I captured the schematic and have decided to use PCB mounted switches and pots where possible. Like the sequencer, it locks in the panel layout, but I think it will make other aspects easier in the long run.
Nyle has been playing around with the Photo MOS switches I want to use to emulate the buss keybed. He thinks they will work well. That is good news as it will make the interface between the Doepfer MTC64 and the Duo Phonic keyboard electronics easier.
Stay tuned. I'm still playing around with video/audio and will post soon.