Have built a Thomas Henry LM-VCO and in the middle of building an Eddy Bergman / YuSynth ADSR and a VCA. Hooked up to an AI Synthesis Stereo Matrix Mixer and Hexinverter Mutant Brain with an Alesis QX-49 keyboard and SR-18 drum machine.
What should I do with the last 10hp of my case?
Oh for sure you can use transistors. Slightly Nasty makes a full fledged VCO from transistors. So a great micro controller would be either the teensy line or even a RP2040 (I think that’s the designation it’s a raspberry pi based microcontroller.). Look up the Europi they have some great code examples you could look at.