Jim Lesurf wrote:
Just to let people know I've updated the content of
http://www.audiomisc.co.uk/Linux/ALS...reSilence.html
slightly.
Having just done a fresh install (Xubuntu 12.04) reminded me of what a
subtle and devious PITA 'Pulse audio' can be! Even having set my alsa
default and told Audacious to use it, Pulse was resampling and applying a
volume control to the data stream in between Audacious and the DAC! The
result was downgraded sound quality for some Audacious settings and weird
errors for other settings.
Un-installed Pulse. End of problems. Bit perfect output.
So I've added a stark warning box to the page, alerting readers.
I'm lucky in having an external DAC which displays the format it is being
fed. So I could immediately see it was being given 44.1k when I played a
96k file. Anyone without such a hardware display may simply not know that
the sound was being needlessly degraded.
I don't know about USB, but for others you can see what is being fed to
the h/w by doing (while playing something) -
cat /proc/asound/card0/pcm0p/sub0/hw_params
Of course the numbers may need changing to suit setup.