@John Mulcahy ,
any idea how to proceed with the issue from post #256?
Using a spare old laptop running an older Linux Mint I now could get the soundcards in question to work in REW (again with pulseaudio removed)... but the question remains, how come
speaker-test and other alsa progs (like
aplay) do work 100% correctly while REW is showing this strage error on the NUC machine (meaning the card is already occupied by another program)?
EDIT: Audacity does work as well.
A more verbose error log what exactly (which alsa library call) went wrong may help debugging the issue. Something like alsa call sequence similar to the sequence in
https://github.com/alsa-project/alsa-utils/blob/master/speaker-test/speaker-test.c, function set_hwparams(), lines 429-543.
One thing I note that in REW we cannot specify direct hardware like one would do with
speaker-test or
aplay (
hw:USABRET in this case), only
USABRET [plughw:1,0] and
USABRET [plughw:1,0] (which opens IMHO unwanted backdoors to hidden resampling).