Alex Tinsley wrote:
> First off any noise that you hear through your USB Audio interface is
> because the grounding in the audio device is using the grounding on the
> laptop which is most commonly data ground wired to earth ground. So you
> hear all computer noise through the audio output. One way to alleviate
> this is to lift the ground on the laptop (unplug the power adapter from
> the laptop or get a ground lift adapter). Noise goes away. A lot of
> devices suffer from this, 1394 has same issue.
I only get noise on my USB soundcard when I plug it into my external
hub. I get no noise with it plugged directly into the laptop. I guess
the laptop ground is OK and the external hub's ground is junk.
The hub has other devices plugged into it, I don't recall if I tried
using it with only the soundcard. Wouldn't be surprised if some of the
other USB devices on the hub (scanner, printer, MIDI interface,
PS/2<>USB adapter for keyboard & mouse, flash card reader) are sources
of noise by themselves.
Thanks for the extensive info!
-- David gnome@email-addr-hidden authenticity, honesty, community _______________________________________________ Linux-audio-user mailing list Linux-audio-user@email-addr-hidden http://lists.linuxaudio.org/listinfo/linux-audio-userReceived on Sat Sep 18 12:15:02 2010
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