NixOS 83: NixOS as a Music Production System

[@ChrisMcDonough]

I figured out why I had to reboot after "adding chrism to the audio group" instead of just being able to log out and log back in. It had nothing to do with me adding him to the audio group. I needed to reboot so the PAM limits.conf stuff got activated. But in Nix's case, they aren't in /etc/pam.d/limits.conf, they wind up in /nix/store/84kvpf48ih1aznj1nshz4s3snc7sysaj-limits.conf on my system and presumably that is symlinked from somewhere. I also listened back to my recording into Ardour in the VM and there's some crackling. I think that's because there's a mismatch between the sample rate that JACK is using and my Edirol sound card, FWIW, but I haven't fully tracked it down. It could just be VM latency; it works fine on real hardware. I also may have misspoken about commercial LV2/VST plugins that work on other Linuces just working if you dump them into a place on the VST path. I haven't tried it, but thinking about it, you might need to set a LD_LIBRARY_PATH before starting Ardour or Audacity or whatever so that those plugins can find their library dependencies in the (non-FHS-compliant) NixOS filesystem. If I get the time, I'll verify.

[@sibeov]

Perhaps the "pops and crackles" are buffer size related? I have these artifacts when buffer size is too small in relation to how fast the CPU can process the samples. And I would guess that running this on a VM or similar would have some effects yes. I often increase the buffer size to max when only doing recording to be on the safe side.

[@sibeov]

First of all thanks for the video! This is interesting and helpful! With regards to kzbin.info/www/bejne/lX7Cp4atfKyJsLs, my guess are, based on the name alone, that they are some sort of Real Time Iterrupt Request for the CPU. Only a guess, but it sort of makes sense that you need to, perhaps, "tune the priorities" of the IRQs when processing data in "real time". Have you perhaps found out more regarding this since posting this video?