PC humming

[skraggs]

Hey everybody,
I got a problem with humming coming from my computer. There are two connections from my PC to my amp:

1. PC - hdmi - TV - optical - opt. converter - rca - AMP
2. PC - usb - Schiit Gungnir MB - rca - AMP

The humming only occurs when both the usb and the hdmi are connected, removing either solves the problem.

Anyone got an idea what I could do?

 

[erniejade]

Is it the same computer going to both? Do you have them plugged into the same outlet? Do you have a power conditioner?

 

[xero-D-hero]

I'd be just a bit suspicious of the optical converter as that should isolate the PC & TV (HDMI) from any noise or such on that side of this rig.

Otherwise it's likely just the "noisy" USB/HDMI bus of the rig and that's a whole other can-O-worms.

Good luck here.

Bret P.

 

[erniejade]

On my rig I use a Intona to help or isolate more. Maybe the power on the usb? Maybe try an Sbooster vbus as long as your dac doesn't use the usb power to it?

 

[skraggs]

Thanks guys!

Otherwise it's likely just the "noisy" USB/HDMI bus of the rig and that's a whole other can-O-worms.

It probably is, I can't make sense of it otherwise. The humming is only there when both USB and HDMI are connected.

 

[heyraz]

Another way for ground loop hum to develop is through the CATV shield. Is there a CATV connection anywhere in there?

 

[gvl]

Try iFi iDefender on the USB connection.

 

[orsen]

sounds like ground loop
i would start with changing rca and usb cables
i would also try having only one rca cable plugged into the amp at a time
no hum add an rca then another [shutting the amp off before adding ]
and see when the hum starts
you may find that a cable is causing the loop
try a separate ground wire run to the pc and the amp just a piece of speaker wire will do

 

[drumbum]

Probably just doesn't know the words