[Ivan Franco] sent us this great synthesizer project that he’s working ... and a Teensy with up to 80 (!) multiplexed analog inputs that you’ll connect up to whatever hardware you desire.

The build revolves around an STM32F7 microcontroller and offers a 6-voice virtual analog synthesizer ... there are other DIY synths that cover that area as well.

Korg’s Nu:Tekt NTS-1 was a pleasant surprise when it arrived a few years ago. A DIY synth kit featuring a single monophonic digital oscillator, but with the ability to host custom sound engines ...