[18inch]

I've been having noise interference that is definitely coming from the ethernet connection on the motherboard. anytime there is any form of download/upload i get that small background noise.
 
Now that I have a more sensitive headphone i actually hear it... a LOT.
 
anyone have this issue.. solutions? good usb quality cable ?

 

[NA Blur]

I think a cable would only fix it if it you were using a poorly grounded cable to begin with.  The chances of that are slim.  A good external DAC is more of what I would expect to help your situation.

 

[18inch]

silly how stupid things that happens can be so simple to fix....
 
i found the issue, I played around with the wi-fi antenna (it was behind the matrix x-sabre), whenever I grab it with my fingers, the sound goes away, its funny.. lol , so Ive put it further away and the annoying download/upload sound went away...

 

[NA Blur]

Great news!

 

[ZianC]

It may be worth using something like InSIDDer to do a spot check for interference from other WiFi access points nearby too.
 
As you discovered, WiFi-related equipment can be a bit of a RF-related headache.