[HiAudio]

The set up is PC mobo ---> nuforce icon HDP via optical ---> HD 650.
I randomly hear noise, sometimes freqently sometimes less freqently. It sounds like electronic noise. It not only annoying but also kills the listening at all. Initicially I thought it was from the CD ROM. But I heard it no matter I use CD rom or play from the hard drive. I heard it when i use Optical, USB or coaxial.  I do not hear that when i connected to my hometheater receiver.So it came from the PC somewhere.I could not figure out where it came from on the PC. Does this happen to others? How do I eliminate it?

 

[cheapous]

There's a lot of useful suggestions in this similar thread.

 

[oshia86]

A list of pc specs couldn't hurt. How is everything setup? Any devices nearby that could be attributing to the noise?
 
I have a similar setup and no issues. I use HDP to drive my HD650's via the usb connection, and have the rca out's connected to my speakers.

 

[HiAudio]

 
The PC specs are rather simple and outside it is not.
 
CPU i7 950
MOBO is evga x58
RAM 24 GB GSkill
HD Crucial SSD 64 GB
Video 1GB
The config is pretty decent
what could be causing the problem is other parts outside it. I used 4 port DVI switch to connect 3 PCs. Wireless keyboard/mouse and speakers were shared. All 3 PCs were wired to a switch which was connected to a router which is connected to cable modem. The router also connect to another laptop. The switch also connects to a printer and VOIP phone box. All PCs were pluged in different UPS. So there are too many wires and too many devices connected one way or another. I would take long hours to eliminate the sources, if possible, one by  one. The problem is it happens randomly and ther eis no reliable way to make a conclusion on any elemination.