Removing noise from my linux PC without an external DAC

[VietnamRadioEnjoyer]

I have a PC with Gigabyte z170-d3h motherboard. There was a "buzzing" noise constantly playing and a "popping" noise when I opened any music file. It was audible on both of the front headphone jack and the line-out on the back of motherboard. I suspected that it was a design flaw of my motherboards soundcard and wanted to buy an apple dongle to fix the issue, until I came across this article.

Boom! one linux command and all the noise was gone like magic. Apparently soundcards have a power saving mode that causes the capacitors to discharge into audio gear and make noise and for some reason this power saving mode is activated by default on linux. Not sure if this is also the case for windows but I'am interested to know

Just wanted to post this here as it might help someone in future

 

[nerdstrike]

Very nice, although there are many kinds of buzz. Something specific about civilization 6 makes a terrific amount of noise on my Windows PC via the much maligned dragonfly red.

I will have a fiddle at some point with registry settings to see if a similar trick can be pulled off on Windows 10.

 

[JSmith]

Not sure if this is also the case for windows but I'am interested to know

Yes, it is and can be altered with a registry changes to;

ConservationIdleTime
IdlePowerState

Audio Device Class Inactivity Timer Implementation - Windows drivers

Audio Device Class Inactivity Timer Implementation

learn.microsoft.com

JSmith

 

[Dunring]

Yeah Windows is bonkers with power management also. In Win10 Pro or higher there's advanced power settings to disable (including setting the hard drive idle to zero seconds so it won't go to sleep. But in any version like Home you can still go into device manager and disable power management for all the USB hubs and ports, and anything else on the list to do with media. It's like Microsoft assumes everyone is using a laptop on a battery. Even network cards and other things that use incredibly small amounts of power have power saving on by default.

 

[AnalogSteph]

I think the noises mentioned have two different causes:

1. The popping is your regular old power-on/off pop noises. These always happen when analog stages running on a single supply voltage are involved. In case of the ALC892 used on this board, it seems to be internally regulating +5 V to about +4.3 V, and in operation the DC voltage level found on its outputs would be about half that. The coupling capacitors on the motherboard keep this DC voltage from actually reaching the jacks, but whenever the chip is turned on or off, it inevitably has to be ramped up or down in a short time. The resulting signal has some non-DC components which do pass through coupling caps, hence the pop. Obviously, if the output stage is kept running all the time, no more pops.

2. The buzzing may be caused by bad audio cable shielding or bad shielding on the board itself. Whenever the output is turned off, the impedance level on the connection becomes very high, potentially tens of kOhms - it's almost the same as the cable being unplugged. That makes it quite susceptible to electrostatic interference. Once the output is turned on, its output impedance drops to no higher than about 275 ohms (200 ohms internal + 75 ohms on the board), and that is dominating connection impedance levels then. Accordingly, the effect of said interference drops way down... possibly as much as 40 dB. That's generally enough to make it inaudible. While this band-aid fix will obviously work, I'd prefer having a proper one as well... this would require taking a closer look at what is actually plugged in there.