ironsheik :
First make sure you have the curret creative audio driver installed from the Gigabyte website.
You hear the noise with headphones because your motherboard has a headphone amplifier, which may be picking up interference. Ferrite can reduce radio waves leaking from cables, but is unlikely to solve your problem which sounds like internal interference. There are many sources of interference, the power supply or a bad motherboard are the most likely. You could experiment by trying to disconnect peripherals looking for a source of interference, but it might come down to the psu or motherboard.
Thanks for your reply.
I've read in many forums that 7950 and 7970s usually have coil whine, but in my case it is very noticeable. It isn't the motherboard because I also had it with my previous AMD one before switching to intel, but now it is more noticeable because probably the op-amp amplifies it. I also know this because with the unamped line-out jack the whine isn't noticeable unless there is complete silence in the room and volume dropped to 0. This weekend I'll try taking out the GPU and using the onboard graphics to see if the sound is gone and discard the PSU.
Also, if I play a game I can hear it physically on the GPU itself, although it is very hard to hear because fans are louder. I'll see if I put it in the bottom PCIe slot it dissapears. If not i'll RMA it.
Also the slight CPU noise may come from the cable that goes next to the CPU, that is very short and I didn't know where to put it, so I just put it over all the components and passes near the audio jacks.