http://www.ruskeys.net/pasp/maestro/pasp.php
Maestro was a synth made in USSR that was designed by Vladimir Kuzmin of Polivoks fame. Maestro takes after Polivoks but adds digitally controlled oscillators and 4-voice polyphony. I learned a few things from studying its circuits.
I think I need to brush up on my Soviet IC codes - I found this, https://elcomps.com/en/a76 from which I can decipher that there are some analogue switch ICs (K157 ?) and maybe some NANDs (K155 ?), but I'd love a big list of codes and the closest Western CMOS equivalent to help understand these.
Some counters, a DAC, a bunch of cd4052-like analog muxes and switches, opamps and even a 555. They use DIN symbols. Unless you want to replicate it exactly, most things can be guessed.
There's also a BBD chip for chorus.