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jareemon
30-09-2011, 04:47 PM
Hi guys, I've been noticing a very annoying but faint background electrical noise in my headphones lately. They were plugged into the front headphone jack, which has the HDA and AC'97 cables, with only the HDA plugged into the motherboard.
I plugged the headphones into the back speaker output (green) port, and the noise was gone.
After a bit of googling, found that this can be caused my the components inside the case giving off electrical noise and being picked up by the HDA cable.
The internal front panel HDA cable itself is only just long enough to reach the motherboard jumper, not even long enough to route the cable properly, so it's touching the cooling shell of the video card, which just happens to be metal. Is there any household sort of stuff i could use to shield the cable? like maybe tin foil?
I mention the video card because the noise is most often heard when something on the screen is moving or changes.
Drivers up to date (VIA HD Audio)
Sannheiser HD202 Headphones
Antec Three Hundred Case
Asus M4N98TD Motherboard
Asus GTX560Ti OC GPU
Windows 7

wratterus
30-09-2011, 04:50 PM
The Antec threehundred and twelvehunderd have a ground loop problem with the front panel audio. I've had the same issue with the twelvehundred, damn stupid design, the engineer who thought earthing the audio with the USBs was a good idea should be hung.

Fortunately for you the threehundred is a heap easier to get at than the twelvehundred. :p

See here for the fix.

http://forums.bit-tech.net/showthread.php?t=208880

http://www.incrysis.com/forums/viewtopic.php?id=29778

http://forums.overclockers.com.au/showthread.php?p=11145597

jareemon
30-09-2011, 05:13 PM
Awesome! Thanks, but isn't the earth kinda there for a reason?

Agent_24
30-09-2011, 05:35 PM
Yes, but the motherboard or soundcard header where the other end of the front panel audio cable plugs in also has a ground.

So even that the ground on the front panel end is going nowhere, it's still connected to ground on the motherboard\soundcard end.

This is actually better because when you have a ground which is connected at more than one location, you get the possibility of a ground loop (because not all points may actually be at ground potential) and the problem you experienced.

jareemon
30-09-2011, 05:47 PM
OK, I think I get it now. I'll make the snip tonight, Thank you!

wainuitech
30-09-2011, 08:24 PM
In a silly mood :D, after reading those instructions about the wire -- I cant help but think of This here (http://bp2.blogger.com/_M0cuxJsSjdU/R8Uwx48QXXI/AAAAAAAACxY/oBtRsG_TW14/s1600-h/Bomb%2520Squad%2520(%2520Funny%2520Co-worker).jpg) :lol: :p

Agent_24
30-09-2011, 10:42 PM
:lol: