Hey guys,
 
Been with EVGA for about 6-7 years or so and unfortunately, the first issue has reared it's head. I've just bought myself a new GTX970 SC from EVGA (sold my SLI GTX680) and the moment I put it in, I was a bit disappointed with the Heaven benchmarks (marginally better than my score in SLI with the two GTX680's). Although, that's beside the point.
 
Since I got it up and running (with ease I may add), I uninstalled my drivers, did a clean sweap with Guru3D's driver sweeper and did a fresh and clean install of the '75 Nvidia drivers. Definitly the latest one. Alright, now we're cookin'. 

I did a benchmark with the GTX970 SC in Heaven and on my Optical Out I heard no noise what so ever. Now, when I met a mate of mine on Skype to play some Battlefield 4, an immense noise came out of my headphones (using 5.1 Roccat Kave with 3x 3.5mm jacks). The sound didn't go away when I (forcibly):

• quit Skype;
• quit BF4;
• Reinstalled the current driver;
• Reinstalled the previous '65 driver;
• Uninstalled EVGA precision;
• Disabled Logitech's Gaming Framwork, AIDA64 and other services
• went into safe mode to listen to the noise;
• played a VLC video;
• moved my mouse around;
• swapped around my GTX970 in the PCIE 2.0 slots;
• moved my RocketRAID card;
• moved my Audigy Z soundcard;
• switched up the PSU power cables (from bundled to extension cables that came with the PSU);
• removed all 3rd party components (Xbox 360 controller, external USB, mouse, keyboard)

Simply, nothing. Now, when I hooked up the GTX680 again, the sound was gone - totally fine, even in game or with a benchmark. So, what would it be? 
 
I'm running:
 
EVGA X58 Classified
EVGA GTX970 SC
Corsair HX1000Watt PSU
Intel i7 920 (tried as stock and OC speed)
6x Corsair Dominator 1866Mhz
Creative SoundBlaster Audigy Z
RocketRAID 2720SGL + 4x Vertex 4 in RAID0
Roccat Kave 5.1 headset
Logitech G19S keyboard
Logitech G9 laser mouse
 
I'm curious to see what you guys can come up with... I'm at a loss and a bit disappointed a this time. 

Im having the same problem. While under load there a buzzing sound come thou the speakers

I had the same problem when I was running a 560ti  and now im running a 970 and it worst  I was reading its something to do with the Realtex audio but I put in a soundblaster card and it was still there so im confused. Maybe its the motherboard but I cant RMA it now its past 3 years
 
I just notice we are both running the same motherboard and cpu    so makes me even wonder more now

can you guys post the exact onboard audio chip model your motherboards have?
and which Realtek driver version you had the issue with?

Might indeed be the same, though I am using Creative's SoundBlazer Z as my audio card... Internals are disabled...
 
Just installed a EAH 5670HD from ATi/Asus into my PC and I got the same squeel goin' on... What is going on?!

Already moved the soundcard around from the 1x to the 3 16x and no cigar. 
I'm thinking it has got something to do with either the PSU or the MOBO at this time, though I have no idea how this problem popped up all of a sudden. It was fine with the same configuration and a dual GTX680 in SLI (with the double EVGA bridge).

Yep, unfortunately EVGA isn't releasing updates from my motherboard anymore - it stems back to 2010. EVGA X58 Classified it should read, I made a typo. 

I did everything I could think of. I even took all the components out of the case and made a barebone setup - same result. Only hooked up a fresh HDD with a fresh Windows 8.1 64bit installation, completely reset the CMOS, replaced the battery, dusted off every component, reapplied thermal paste... I could go on and on.
 
I think the fact of the matter may be that after 5 solid and trustworthy years, my x58 Classified might have thrown in the towel... Good thing I got 10 years of warranty and 5 left.