linuxaudio.org

Alex Tinsley wrote:
> First off any noise that you hear through your USB Audio interface is

quoted text
> 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@hawaii.rr.com

authenticity, honesty, community

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