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.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

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.

In article , Andy Furniss
wrote:
Jim Lesurf wrote:
Just to let people know I've updated the content of

http://www.audiomisc.co.uk/Linux/ALS...reSilence.html


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.

Thanks for pointing that out. :-) I'll either add it as an extra to the
existing page, or include it on a future page.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html