AX760 really annoying harmonics

Hi, recently put together a new PC Build, thought I'd splash out on high quality PSU so went with the AX760.



I had hoped it would be ultra quiet, and I'm using very quiet case fans so didn't want any whine, but there's a problem.



We're not even talking super high frequency here either, its a few harmonics but the one that really sticks out to my ears is a 1khz tone. Once my brains latched onto it it drives me a bit crazy, and that sine wave just seems to travel through everything.



Here's a couple recordings I made using a field recorder, placed right up against the PSU grill. One is the AX760, the other is a much older NesteQ PSU I have in my other PC, no mid-range harmonic issues whatsoever:



http://ift.tt/1r2iIWO

http://ift.tt/TuT7ag



Here's the frequency plot for both (with 4db/oct slope):









Is this considered normal for an AX760? Is that the price for high efficiency, if so should I get a gold or bronze certified one instead? Is it even likely this noise will reduce over time or get worse?



I'm concerned if I RMA it i'll just get another one with whiney noises.



I should also state that I dont think this is a bios issue as it makes this noise even when the PC is off, just mains supplying power to the PSU, with the little red power symbal lit on the motherboard (but not actually running).



Windows running or not, the harmonics are still there same level and I dont really want to run my case fans super loud to try and drown the sound it, kinda defeats the point of building a quiet PC :/