Been doing some more testing and it seems that ALAC on occasion causes the distorted sound.
In each such case, reboot of ROON fixes the issue.
The tracks are ripped from CD using XLD Secure Ripper, bought from HDTracks.
The only common trait is the format - ALAC.
Roon on ROCK - Intel NUC Corei7, 16GB RAM, Internal data SSD
Gigabit switch with Cat 6 cables
Signal Path always: Source (ALAC 44.1Khz 16bit 2ch) -> Sonore microRendu -> USB Output.
DSP is disabled.
Update: On one track (re-ripped to FLAC), it appears that playing FLAC version will just skip (no sound) the bad section (of less than 1/4 second or so), whereas ALAC version will add audible distortion. Undeniably handling of FLAC is better.
Had to listen in headphones to detect that one. ALAC was clearly audible.
Also, the FLAC appears to sound a bit better than ALAC.
In the rest of the cases, rebooting the ROCK fixes the issue. I just didn’t test this track, sorry. Noticed the difference in FLAC by chance. On my main system that hiccup was inaudible on FLAC and a very audible (repeatable) distortion on ALAC.
Question: is that ROCK specific (decoder), or Roon specific?
I even started to consider installing Windows 10 and running Roon Core on that one (not a preferred option).
I really don’t want to get forced into re-ripping/transcoding everything to FLAC.
Thank you very much in advance!
Update 2: Happened again on known good files. Reboot fixes it.
Replayed the same track after restart - played just fine.
This happens fairly regularly with random albums.