How to eliminate PC static noise? High end entertainment PC.

Hello All,

I am having a rather annoying problem with static noise through headphones. The PC supposed to be some of the best money can buy running i7 6700K 16GB RAM Gygabyte mobo and a brand new 750 watt Corsair bronze PSU.

I've just picked up a set of rather high end Stax SRS-3170 electrostatic headphones which comes with its own amp, all is well except I am hearing huge amounts of static coming from the PC. The headphone amp is connected via analogue high quality cables which are hooked up to my main Onkyo TX-NR 3030 receiver via Zone 2 pre out. I Can confirm other sources don't make noise.

The noise is like having an ancient dial up modem squeaking in my ears constantly and the tone and intensity changes depending on what I do on the PC, it seems to be the worst when browsing the web and have a white or very bright background displayed.

Audio is hooked up to the main receiver via HDMI bitstream from the video card GTX 970. When the PC is off no noise so its not the amp, cables or the receiver. Could it be PSU chatter getting through???

I am going away for a couple of days so apologies for not replying but hoping I'll have some good suggestions here by the time I get back as its rather annoying having top of the line equipment and having such a problem.

Thanks