Score:0

Constant static through sound card

de flag

I have constant, low-level static coming through the sound card.
It goes away for about a half a second if I kill pulseaudio with pulseaudio -k. It isn't a ground loop, since everything is running through the same outlet and single-point grounded.

I have tried going into the main audio settings and it goes away immediately if I change the input device. But that seems to only happen because whenever I change the input device, it changes the output device automatically to the wrong one. I have tried disabling the mic input and over-amplification. I have even tried putting in a new sound card. Nothing helped.

I'm running Ubuntu 20.04 and an SB1550 sound card, but the problem is the same with the built-in motherboard sound card as well.

Does anyone have any ideas?

uz flag
Jos
A bit of a long shot, but do you have an Ethernet cable into your system, and does it get better if you pull the cable out? (It does so on my old Windows computer.)
Jessica avatar
de flag
That's a good thought, but it didn't have any effect
pktiuk avatar
us flag
Is it just a static or something rather similar to cracking?
Score:0
us flag

I think you could check audio troubleshooting guide from here

In case of audio cracking it may be caused pulseaudio putting your audio card to sleep too often.

To fix this, you can use command:

sudo sed -i 's/load-module module-suspend-on-idle/#load-module module-suspend-on-idle/' /etc/pulse/default.pa
pulseaudio -k

To undo this change just use:

sudo sed -i 's/#load-module module-suspend-on-idle/load-module module-suspend-on-idle/' /etc/pulse/default.pa
pulseaudio -k
Jessica avatar
de flag
Thanks, I followed the instructions. The first step didn't change anything, so I ran the second command to set it back to normal, and now it stops the crackling when the sound card is idle, but it comes back immediately if I play something. At least I don't have to listen to it when I'm not playing anything, so that is an improvement.
Score:0
de flag

Turns out it actually was a grounding issue. I had thought that I checked continuity to the furthest ground point, but turns out the sound mixer was running through a separate power strip, and when I put the ohm meter on it, the ground was indeed open circuited somehow. I replaced the power strip and now the noise is gone.

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