Subject: Re: [linux-audio-user] unwanted noise in soundcard
From: Steve Harris (S.W.Harris_AT_ecs.soton.ac.uk)
Date: Mon Aug 26 2002 - 11:19:03 EEST
On Mon, Aug 26, 2002 at 03:48:25 +0200, dplist_AT_free.fr wrote:
> I own a M-Audio Delta 66 + Omni I/O (breakout + preamp box) that I
> use with alsa-drivers-0.9rc3. jackd, ardour, envy24control seem to
> work fine but I can hear unwanted noise in both left and right
> monitoring channels. The noise is sometimes very present, sometimes less
It could be a ground loop. Could you put a recording of the noise up
somewhere? I've had this problem when using a laptop plugged into the
mains with a projector and mixer on different mains circuits.
For me most of the noise appeared to come from the cdrom drive (it was
intime with the flashing light), but it was the ground loop that caused
the problem. Unplugging the laptop from the mains fixed it - not that that
really helps here.
I've also had nightmare ground loops at a gig, triggered by a MIDI chain -
I solved that with a di box IIRC.
Check how your monitor, mixer and pc are grounded. There is some advice
about fixing problems here:
http://www.sospubs.co.uk/sos/1994_articles/aug94/groundloops.html
- Steve
This archive was generated by hypermail 2b28 : Mon Aug 26 2002 - 11:15:30 EEST