[LAU] Question about Behringer UCA202 USB audio device

[Justin Smith]

On Tue, Jan 13, 2009 at 12:53 AM, david <gnome at hawaii.rr.com> wrote:
> Is it normal for it to have more-or-less constant low-frequency pops and
> crackles while playing quiet passages, and occasional louder pops even
> in louder passages? These are files that were digitally generated
> (sample recordings of the Aeolus organ synthesizer) or ripped from CDs,
> so they weren't analog recordings that might have such additional
> natural sounds.
>
> TIA.
>
> --
> David
> gnome at hawaii.rr.com
> authenticity, honesty, community
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> Linux-audio-user at lists.linuxaudio.org
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>

Try the "test audio and midi" menu item in puredata, with the test
signal on the "-40" setting (or some other low level reference signal
of your choosing). If you get the same low frequency pops and static,
it is your sound card or driver (most likely the card). From your
description it could be a ground loop - does it go away if the sound
card is attached to a laptop on battery power?