Scratchy audio on Linux


I installed Sonic Pi on Linux (I know it is not officially supported). Version 4.03 and it works so far.

However, have a slight scratch in the audio.

Does anyone know what could be the issue?


Could be xruns in Supercollider. Are you using your install with pulse audio or using audio output set up using Qjackctl?
You can try adjusting the settings for this number of periods, buffer size and sample rate. It is a trade off betweeen latency and preventing Xruns which will give scratchy audio.

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Hi, thank you for the quick reply.

The issue seems to have disappeared over night, for now. No idea why.

I followed some online instructions a while ago. Audio says “Jack sink PulseAudio to Jack”.

It works for now but it still seems like something happens to my audio once I open sonic pi. Cant hear some other apps etc. Restart fixes it though.

Explaining all the things that happen when Jack enters the stage would take a while but not hearing other apps is one of the symptoms. I suggest you use the Flatpak version of Sonic Pi. If you are using a distribution that has made the switch to Pipewire you’ll need jack-tools or jack-audio-tools. It seems you are on PulseAudio tough and let’s say I’m glad I’m no longer using that for anything pro-audio related. Still, using the Flatpak version is your best bet to get a smooth experience, including midi and osc support, regardless of what audio server you’re using.

Thanks for all the input, @R2L !

Just to clarify, should i install this version?

Thank you!

No, that’s a version packaged in a deb file. I was referring to this: Sonic Pi | Flathub

Setting up Flatpak for Ubuntu is described here: Flathub-setup voor Ubuntu | Flathub

Then install Sonic Pi with flatpak install flathub net.sonic_pi.SonicPi, it should show up in the launcher menu but if it doesn’t you can launch it with flatpak run net.sonic_pi.SonicPi.

Hi, thanks for the input.

I was able to install Sonic Pi and it also shows in the launcher menu.

But when I try to start the app, nothing happens for a while and then I receive a boo error.
I dont really understand what the details mean.
Any idea whate might be the problem? Thanks!


That’s really unfortunate, I have never seen that issue before. I can’t find the maintainer for the flatpak build so I don’t know where to go with this. I see you are using KDE, which I’ve never tried but you should be able to run the DE of you choice. I have run on Gnome, LXQT, LXDE and XFCE.

As a last resort you can try compiling Sonic Pi yourself, I have written some remarsk on how to do this on Linux here but this was in 2022 and I’ve switched to the Flatpak version since.

You might want to read up on Jack as gaining a deeper understanding on the mess Linux audio is can help you tweak your settings to get rid of pops and cracks. There is also a Python script that can help identify settings on your system that are sub-optimal for sound producing.

Also check if the cracks persist if you record your session, like just hit the record button in Sonic Pi, play around a bit with something that gives you scratchy sound and stop the recording. Then listen back to the recording and hear if the scratching is there. I had an issue where I was pushing my system hard so I had cracks and pops all over the place but the recording was absolutely fine.

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