Edited: Just realized, probably it would sound awful with 8 original bits scaled down to even less... But idea would still be practical with 16 bit or 24 bit R2R. Only less outputs 'd be available
Yup, that's the whole problem. That's why I want to do something in analog-domain. ;-)
I did some testing with OP-Amps, but since I have on clue on what I'm doing, it did sound good, until the volume lowered, then it didn't sound that good anymore. So I guess its a bit more complex to handle this out. Those VCA schemes I posted above are nice, but still a bit complicated, if I want to add 6 or 8 times those circuits, to get multiple voices. :astonished:
Take, for instance, the Beat707 SY LE project I did: https://github.com/Beat707/Beat707-SY-LE
If I could add at least 4 x 8 bit PWM outputs as the Envelope CV, that would be great. It would end up with at least 4 voices with 2 Square Osc each, not bad, all in a single chip design. Now add another ATmega328 or even run it at 20 Mhz, and improve even better the system. Then I could, later, find a way to add analog filters to it, also in simple terms.
I was hoping to get that with transistors or simple op-amps. But I don't know, it seems it would be more complicated than that. I will experiment some more another time.
The idea is to keep the whole thing as simple as possible. I know I could do all this in code, like the MidiVox did, but it only does one voice and I didn't like the sound...