Subject: Re: [linux-audio-user] unwanted noise in soundcard
From: Son of Zev (sonofzev_AT_labyrinth.net.au)
Date: Sun Sep 01 2002 - 10:02:18 EEST
What do you describe as digital noise?
The only digital noise is clipping really and that's really ugly..
You could simply have the very common problem of RF interference from
You could of course try getting better cables for everything (monitor ..
and all other devices) and put tirodial cores around them (those funny
big cylindrical clamps.... That would help reduce RF interference from
I have the same sound card and have very little noise at all... but have
experienced it when ground loops have been present and also simply from
a cheap monitor cable....
On Sun, 2002-09-01 at 03:35, dplist_AT_free.fr wrote:
> On Mon, 26 Aug 2002 09:19:03 +0100
> Steve Harris <S.W.Harris_AT_ecs.soton.ac.uk> wrote:
> > 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.
> Sorry for replying so late, I haven't been able to find time
> until now. I've put a recording of that bad noise on :
> or the bigger http://dplist.free.fr/mono.wav
> The noise in the file is louder than normal because it has been
> amplified through my beakout box preamp, but it doesn't matter much
> Do you think it could be caused by a PC hardware problem (pci bus ?) ?
> by a kernel problem ? by the alsa driver ? by the sound card itself ?
> (in that case I'll have to return it).
> Thanks a lot for giving me your opinion on this.
> > 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
> Thanks for the pointer. I don't think I'm experiencing a ground
> loop though, given the type of noise I hear. It sounds like "digital"
> noise to me.
> Thanks again and have a nice day.
> > - Steve
-- Linux: Because a PC is a terrible thing to waste. (By komarimf_AT_craft.camp.clarkson.edu, Mark Komarinski)
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