Graphics, sound and multimedia • Re: Zero2 analog synth demo

Thanks for the reply, glad you found it useful! I'm curious why UAC2 and MIDI isn't working out for your use case. I wish I knew more about how they work, I've really only found what works for me. Hence the question, why can't I have more than two audio interfaces? Do keep in mind I've got the 2x 27-channel interfaces running at a lowly 4 kHz. Still, 27 channels is on par with the bandwidth of stereo 48 kHz per interface. And this is all headless, no video.

I originally ran this on a Pi Zero and it worked. Well, occasional glitches in the audio stream but it did work. The daemon process runs at a privileged priority (SCHED_FIFO). When I switched to a Pi Zero2 the occasional glitches dropped. I also dedicated two cpus to the process (isolcpus=2-3 on boot), applicable to the Zero2. Finally, note in that second video the threading details. I've a thread specific to MIDI handling and one for Audio, and the two don't lock on each other so no overhead there.

Switching gears, I completed the third deep dive video. This one goes into gory detail on the hardware components. Lots of stuff on the signal bus that communicates with voice cards: lots on I2C and SPI. Also details on autotuning the components: calibration & correcting for tracking in the analog oscillators and filters.

https://www.youtube.com/watch?v=C-MREijqNOM

Statistics: Posted by brer_rabbit — Sat May 25, 2024 3:35 am

---