Subject: Re: [linux-audio-user] noise from soundcard
From: Joshua Haberman (joshua_AT_haberman.com)
Date: Fri Oct 17 2003 - 01:57:44 EEST
Thanks for the responses everyone!
On Thu, 2003-10-16 at 15:06, Tommi Sakari Uimonen wrote:
> Do you hear the same noise with headphones in the Sound Blaster card and
> all other outputs/inputs disconnected from all cards?
No!! The noise goes away completely (and I get good signal levels)! Cool.
> I suggest that you take your electricity for the computer and amplifier
> and all that get's physically connected to them from one grounded outlet.
> And beware if you have antennas connected to the system, they give ground
> loop humming also.
I tried putting everything on the same power strip and I still get the
noise. I have a mixer and an amplifier that the signal is going
through, and I get the same noise going:
computer -> mixer -> headphones
computer -> amp -> speakers
as I get going
computer -> mixer -> amp -> speakers
On Thu, 2003-10-16 at 15:35, Jesse Chappell wrote:
> Joshua Haberman wrote on Thu, 16-Oct-2003:
>
> > This is a little off-topic, but I hope you don't mind. I get quite a
> > lot of noise from my soundcard. There is a pulsing that sounds
> > something like a very fast morse code at a consistent pitch, and it's
> > unacceptably loud. I notice variations in this noise based on how I
> > move my mouse.
>
> It appears to be system load based, it might be an internal voltage
> interaction when your CPU goes from idle to active. I've seen
> this before..... try to run this at a bash prompt:
> while true; do yes > /dev/null ; done
This takes away a large part of the noise. There is still some noise
that sounds different, and I can still hear my mouse move. When I move
my mouse vigorously, it starts sounding closer to what it sounds like
when that shell script is not running.
Josh
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