Hi there, I gave Patchbox OS on a Raspberry 3 B+ a try, using a Behringer UCA 202 USB audio interface. While on standard Raspbian distribution I was able to get decent latency (Buffer 256/periods 2/ 44.1kHz), I wasn’t able on Patchbox OS. I tried different sample rates, frames/period up to 1024 / 8, 12, 16 periods so latency became unusable low and even though had massive crackles in audio rate area (sounds like there is a “distortion layer” over the original sound). I tried qsynth with the default GM SF2 library that is prooved to run smoothly on the used hardware. Sometimes the crackels dissapear to re-appear seconds later, no CPU peaks or other trigger events could be identified. Anyone experienced similar problems? Cheers, Synthfluencer
Patchbox uses Jack as the backend. You could try disabling it by closing all audio software and running
sudo systemctl stop jack, then launch qsynth, configure it to use ALSA directly, and see if it’s better.