Greetings. I use Audacity to capture sound from my main stereo, usually to rip vinyl LPs to digital files. Using either Xubuntu (22.04 and 24.04) or Mint (21.x), on line in recording I always get static-like spurious noise. The noise did not occur in initial releases of X 22.04 but might have started after an update. I had tried changing the buffer settings but no improvement resulted. I was hoping that with 24.04 the problem might have been fixed, but no joy.
My workaround, if you can call it that, is to use a Win7 PC for my recordings. (No security concerns because it does not connect to a network.) It makes noise-free recordings with no adjustments needed other than volume level, on both Audacity 2.x and 3.x.
This appears to be a common problem but I have not found any suggestions other than the aforementioned buffer settings. Any advice is greatly appreciated.