[nicholars]

In my new PC I have a GTX 970 graphics card which buzzes during gaming, this is reasonably normal for these cards and I am not bothered about it (I have had 4 and they all buzz), however the buzzing is picked up on my speakers when the amplifier volume is turned up.... here is the strange part, when my TV is connected to the amp via a 3.5mm > Dual RCA cable (for listening to normal TV through speakers on a different input selector on front of amp to PC), the buzzing interference sound is about 5x louder, and when I unplug the 3.5mm cable from the TV the buzzing is inaudible at anything other than slight buzzing at 100% volume on the amp (I also have my PC connected to the TV via HDMI on GTX 970 which I play games on).
 
So I have ordered a Fiio D03k to connect the TV to the amp via the optical port > Fiio D03k > RCA cable > amp, I am thinking this will probably stop the problem of the 3.5mm > dual RCA cable amplifying the interference from the graphics card, I do not entirely understand why it does this, I think it might be something to do with a ground loop but I do not know enough to understand properly, anyway I have a feeling the optical > DAC > amp will fix the problem as optical cables are known to be good for stopping interference or ground loops as they are not conductive.
 
If the fiio doesn't work and I cannot find any other solutions, I will be forced to sell the Xonar STX and buy an external DAC to have the TV and PC (xonar STX via RCA out) connected to the amp at the same time without loud interference during games, which I would rather not do.. So if the fiio doesn't work is there anything else I can try? I was thinking of putting ferrites somewhere and seeing if that helps.... Not sure what else I can do to diagnose / fix the problem, its definitely from the graphics card because the sound through the speakers matches the tone of the buzzing from the graphics card (which changes tone when moving mouse in games etc.. and the speakers make the same noise).
 
If the fiio D03K via optical does fix the loud buzzing (which I have a feeling it will as unplugging the 3.5mm cable from the TV stops 90% of the buzzing noise) and I am left with a very small amount of buzzing that is inaudible at normal volumes... Is there any chance this could damage my precious amplifier or speakers? I read ground loops can damage equipment, but when the 3.5mm > RCA cable to the TV is disconnected the buzzing is non existant until 75% volume and slightly audible at 100% volume on amp, so does not cause any problems as I never go past 60% volume anyway and even at 100% it is not loud at all, do you think this is still something that could cause problems or damage the amplifier and needs fixing another way?
 
The buzzing when connected to both the TV and PC is noticeable at 30% volume and very obvious at 100% volume, when I unplug the 3.5mm > dual RCA cable that connects TV to amp, the buzzing is really not loud at all even at 100% on the amp, but it still bothers me a bit as it should not buzz at all at any volume. I don't know anything else I can do other than the optical cable or ferrite chokes. Can anyone with more knowledge of this sort of stuff give me any advice please?

 

[chsknight]

I have a similar problem which i believe is being caused by a ground loop.  What I did as a temporary solution is have i have computer connected to outlet A and my speakers are connected via extension cord to outlet B.  This eliminated the noise completely.
 
I have a Focusrite Scarlett 2i2 on the way(replacing a Asus Xonar DX) and I hope using balanced cables will solve my problem.

 

[nicholars]

  I have a similar problem which i believe is being caused by a ground loop.  What I did as a temporary solution is have i have computer connected to outlet A and my speakers are connected via extension cord to outlet B.  This eliminated the noise completely.
 
I have a Focusrite Scarlett 2i2 on the way(replacing a Asus Xonar DX) and I hope using balanced cables will solve my problem.

 
That's interesting because the first bit of info when reading about fixing a ground loop is to have both plugged into the same outlet.
 
Should be getting my Fiio D3 through soon so I can connect the TV via the optical and hopefully fix the problem. I don't know if my problem is actually a ground loop or not it is weird.

 

[BeatsWork]

So the buzzing disappears with RCA cable plugged in to sound card but disconnected from TV? And is there a separate jack on sound card for line out vs. headphone out? Or software to configure jack?  If you disable soundcard and use onboard audio same result?  Sorry, more troubleshooting steps than answers

 

[nicholars]

 
So the buzzing disappears with RCA cable plugged in to sound card but disconnected from TV? And is there a separate jack on sound card for line out vs. headphone out? Or software to configure jack?  If you disable soundcard and use onboard audio same result?  Sorry, more troubleshooting steps than answers

 
I have Xonar STX connected to amp through the RCA outs, when it is only the PC connected to the amp there is an extremely slight buzzing when at above 80% volume which on this amp is extremely loud, I never use it over 60% volume anyway so it is not a problem (unless it could be possibly causing damage to the amp?), the problem happens when the amp is also connected to my TV via the headphone out on the TV using a dual RCA > 3.mm jack cable, when I have both plugged in the amount of noise is amplified by about 5 times and is audible at anything above about 40% and quite loud at 100% volume (with the actual game sound turned off and amp volume on max), so for some reason having the second connection to the TV makes the noise quite noticeable where I would probably have never noticed it otherwise.
 
At the moment I am just using it with the TV disconnected at the TV's headphone jack and I do not notice any interference in use. I have also ordered a Fiio D03k so I can wire up the TV through the optical port instead of headphone jack and I have a feeling that will work, if not I have no choice but to get an external dac or put up with it. It worries me a bit that it might cause damage to the amp, as I read somewhere that ground loops can damage amps, but I don't know if it is a actually ground loop or what.
 
Through the STX headphone jack there is no buzzing at all at any volume, only on the RCA out and only noticeable when the TV is plugged in as well, very small amount of buzzing / interference when TV is unplugged only at 80-100% volume. I could try using a 3.5mm > RCA cable from the onboard sound line out, have not tried that yet, but its wouldn't be solving the problem as obviously I want to use the STX. I will try the fiio when I get it and hopefully that will sort it out but if possible I would like to remove all buzzing completely at any volume.

 

[BeatsWork]

What you're describing sounds like classic ground loop so obvious steps as you already indicated would be to try optical cables from TV and or Sound card to amp. Would also try plugging everything in to one power strip. Would also unseat and re-seat your soundcard and graphics card to make sure you have a solid connection. Having the card itself physically produce a buzz when moving mouse sounds like poor grounding or shielding in PC itself. You might be better served posting question in forum like over clock.net on how to troubleshoot PC grounding/noise issues.

 

[cel4145]

What you're describing sounds like classic ground loop so obvious steps as you already indicated would be to try optical cables from TV and or Sound card to amp. Would also try plugging everything in to one power strip. Would also unseat and re-seat your soundcard and graphics card to make sure you have a solid connection. Having the card itself physically produce a buzz when moving mouse sounds like poor grounding or shielding in PC itself. You might be better served posting question in forum like over clock.net on how to troubleshoot PC grounding/noise issues.

+1

Definitely explore ground loop as the probably cause before moving to other problems.

 

[chsknight]

Would balanced vs unbalanced cables have anything to do with this?

 

[nicholars]

My speakers do not make any noise at all during normal use, eg. on desktop or web etc. And the headphone output on STX is 100% noise free. They only buzz when playing 3D games with sound through the RCA outs > amp > speakers, the graphics card makes a buzzing noise during 3D load, which on its own is not noticeable unless you put your ear behind the computer and I think most / all GTX 970's buzz because I went through 4 cards and they all buzzed. The only problem is the interference through the speakers (only when gaming), if I move the mouse / controller around the tone of the buzzing changes slightly and the sound through the speakers matches it (if I have all sound turned off but the amp on 100% its quiet even at 100% BUT when I plug the TV via the headphone jack into another input of the amp it gets about 3-5x louder, which makes me think it is some sort of loop somewhere but I have no idea how or WHY it is happening)....
 
So if I eventually get this fiio through the post which is taking ages, and that gets rid of 95% of the problem eg. it only makes a buzzing noise which is never noticeable in normal use and only slightly noticeable at 100% volume with all sounds off, do you think this has fixed the problem or should I still be worried about possible damage to the amp etc. and try to fix it completely?
 
I don't know how it could be a ground loop as I did not make any mistakes building the PC so I don't see why it would have problems with grounding, I don't understand it I am sort of stumped as to how I could fix it if the fiio D03K doesn't work. (other than selling the STX and buying an external DAC / AMP connected via optical, which I cannot really afford but I do sort of want one of those NAD D1050 lol)

 

[nicholars]

  Would balanced vs unbalanced cables have anything to do with this?

 
It might help but I don't have any balanced equipment.