On the one hand, I do projects like #muvco to learn new things. On the other hand, that means I spend a l o t of time on sidequests.

Finally learning #python #asyncio so my #multisynth[1] concept has a fighting chance to work right in #micropython (still not willing to go to C for this...)

[1]There's surely already a name for this pretty obvious #synth concept, but I haven't come across it yet. "chordal synth" might be more descriptive but also less accurate, at least how I'm doing it.

Was laying out the #kicad #schematic for #muvco and it started to seem too pedestrian.

Went back and realized I had been using the #pcm5102 wrong and it does indeed do exactly what I originally wanted.

Now making a waveform generator instead of using the dds #ad9833. Much more flexible in shape and can be semi-polysynth ("chordal #synth"?) #synthdiy

Can now generate a perfect 5th in 260us! In mostly-unoptimized #micropython! Just dyads still--need to generalize to larger chords + diff shapes.

Ugh, there's a problem with the through-zero linear fm "just flip the phase 180" idea for #muvco.

#AD9833 works with a phase accumulator. Meaning it just counts up in a ramp at a rate given by the freq. Then it adds the phase register.

When I flip to the other phase register, it's a discontinuous jump = an audio pop.

Can't count backwards. Don't know where I am in the phase (I think) so I can't just add 180 to that (the #math way)

Maybe just a low-pass #filter to drop the pop?

#synthdiy

For some dimwitted reason I didn't put my FM controls on the newer #muvco prototype breadboards when I reworked the input/output chains.

I think I'm ready to implement through-zero linear FM, but I don't have a hardware interface to attach it to!

Gotta figure out another way to test. Or rebuild Yet Again?

And if I'm doing that, should I add an exponential FM switch? The software side would be trivial to handle and the hardware just takes an extra toggle. Maybe even just use a pushpot for lvl

I threw an FM knob on the #muvco just b/c I thought I oughtta. Getting to that part now, it looks like I'd prefer linear FM with "through-zero"

Conceptually, that's really simple to add purely in software with the #esp32 + #ad9833 b/c it has two phase registers. Init them to 0 and 180 and flip when the frequency sign toggles.

Hopefully takes just an hour or two today. Then I could hook the VCO into existing VCF/VCA #eurorack modules and retry Bach a little more musically.

So the #midi sounds pretty good on the #muvco now. It sounds fine on either vco.

But if I play two *different* tracks (from the same song, I mean) I get a timing problem (haven't timed it, but less than a second). Playing the same track on both vcos simul sounds fine. (using #uasyncio #micropython)

Really seems like I must be parsing the midi consistently wrong, but I don't see how.

#python #programming #synthdiy