Non-Snake Oil Power/Line Conditioner?

[SuicideSquid]

It definitely sounds like a ground loop. Mains- and earth-bourne noise should be rejected by any quality audio devices. I would find a way to move to balanced working or introduce a fibre section.

I'm not sure I understand what you're suggesting. As noted above (several times at this point), moving to an optical HDMI cable did not solve the issue. PC does not have a SPDIF optical output, but if it did it wouldn't resolve the issue as it would not transmit atmos signals. "Balanced" is not an option afaik for transmitting Atmos, and the only audio outs from my PC are digital over HDMI or stereo analog from the motherboard.

 

[lemmy_collins]

Since "ungrounding" the PC solve the problem, i'll look around it...
Is the PC case properly grounded ?
Maybe one PC element is not properly grounded ? Maybe the video board heat sink ?
Be aware that grounding aluminium part is hard to keep good since aluminium oxydation could kill a good contact after some times...
good luck

 

[audio_tony]

I have another PC upstairs that's primarily for recording music, it has a GeForce 1070. I hadn't considered swapping it out to see if the problem persists. Issue with that is that even if it shows that it's a GPU or motherboard issue, I'm not really inclined to drop several hundred (or almost a thousand, thanks GPU price inflation) dollars on a replacement if a much less expensive power conditioner/filter might also fix the issue (or if I can just keep running un-earthed, which is a risk, but a minor one).

I can understand you don't want to throw more money at the issue - but if you can at least confirm the source of the problem, then going forward that may well assist in finding a viable solution to the problem.

Problems like this are often best solved by a process of elimination - and 'out of the box' thinking.

 

[SuicideSquid]

Since "ungrounding" the PC solve the problem, i'll look around it...
Is the PC case properly grounded ?
Maybe one PC element is not properly grounded ? Maybe the video board heat sink ?
Be aware that grounding aluminium part is hard to keep good since aluminium oxydation could kill a good contact after some times...
good luck

I was actually wondering about this. The motherboard is properly mounted to the case and will ground to the case via the ATX plate and mounting screws. Should the GPU heatsink ground to the case at all? I've been building PCs for 25 years and have never physically grounded a heatsink to the case.

I can understand you don't want to throw more money at the issue - but if you can at least confirm the source of the problem, then going forward that may well assist in finding a viable solution to the problem.

Problems like this are often best solved by a process of elimination - and 'out of the box' thinking.

Totally, I am going to try hooking up the other PC and seeing what happens.

 

[lemmy_collins]

I've been building PCs for 25 years and have never physically grounded a heatsink to the case.

25y i haven't built one...
grounding the heat sink is probably not too difficult to check if you are ok to scratch its coating.

edit: googling for "heatsink grounding" give some interesting results like this one:

EMI from Capacitor Heatsinks and What You Can Do About It

Whether you like it or not, EMI from heatsinks will always be an issue if they are not sized correctly. This latest blog discuss about how you can prevent EMI from your heatsinks. Read now.

resources.altium.com

 

[Matias]

I would just run the PC without ground and that's it. Remember: ground loops only happen when there are multiple connections to ground in the first place, so the PC is still grounded by the rest of the system.

 

[audio_tony]

I would just run the PC without ground and that's it. Remember: ground loops only happen when there are multiple connections to ground in the first place, so the PC is still grounded by the rest of the system.

Which is true but... You have to remember that the route to ground needs to be able to carry the full burden current.

An undersized ground wire (for example the thin earth wire in a USB or HDMI cable) could go open circuit in the event of a serious fault, leaving the case of the PC live.

I would at least try 'lifting' the ground by inserting a 10 ohm 5 watt resistor in the earth path between PC and ground.

 

[jrosser]

I'm not sure I understand what you're suggesting. As noted above (several times at this point), moving to an optical HDMI cable did not solve the issue. PC does not have a SPDIF optical output, but if it did it wouldn't resolve the issue as it would not transmit atmos signals. "Balanced" is not an option afaik for transmitting Atmos, and the only audio outs from my PC are digital over HDMI or stereo analog from the motherboard.

There are several different types of optical hdmi cable, some of which break the ground, and some don't.

This one https://www.qed.co.uk/optical-ultra-high-speed-hdmi.html#tab1 is "Hybrid construction utilizes both fiber and copper" so would not provide any break in the ground.

This one https://www.lightoptics.co.uk/produ...emovable-mpo-connector?variant=43608462164226 is 100% fibre and has no ground connection between the ends at all.

It's necessary to pick the correct type depending what you want to achieve.

 

[Audiofire]

best power conditioner is still a simple double conversion UPS, where the device connected to it is fed by the battery

For a PSU with power factor correction like a decent desktop PC, which needs it to prevent a critical data error from power outages anyway.

 

[SuicideSquid]

There are several different types of optical hdmi cable, some of which break the ground, and some don't.

This one https://www.qed.co.uk/optical-ultra-high-speed-hdmi.html#tab1 is "Hybrid construction utilizes both fiber and copper" so would not provide any break in the ground.

This one https://www.lightoptics.co.uk/produ...emovable-mpo-connector?variant=43608462164226 is 100% fibre and has no ground connection between the ends at all.

It's necessary to pick the correct type depending what you want to achieve.

Ugh, I guess that's a possibility. I'm not really inclined to spend $250 on an HDMI cable.

 

[Audiofire]

Should the GPU heatsink ground to the case at all?

Continuity tests resolve whether a ground connection is present. Of course, ground loops are avoided. Short circuits are also avoided and could be an issue with the heatsink.

 

[audio_tony]

Instead of grounding the heatsink, I would decouple it to ground with a 100nF capacitor which will suppress any EMI. I doubt very much if that's even an issue here though.

 

[JayGilb]

I would just run the PC without ground and that's it. Remember: ground loops only happen when there are multiple connections to ground in the first place, so the PC is still grounded by the rest of the system.

The OP also uses his pc for recording music and it's not recommended to use microphones or guitars on a system without a proper ground.

 

[SuicideSquid]

The OP also uses his pc for recording music and it's not recommended to use microphones or guitars on a system without a proper ground.

Different PCs

 

[Deleted member 68495]

Tripp Lite or Furman.

Thanks, this is a useful piece of information, found Furman on Thoman for a reasonable price

 

[Pin]

I’m curious if there is a coax cable feeding a cable box /component tied into this system. If so, disconnect it to see if the noise stops.

While I have not seen your problem specifically, I have seen improperly grounded coax cable in both old and new homes causing problems. The result reveals itself as noise from a component that is sensitive to those problems.

The electricians wire up everything just fine normally- but then the cable company comes later and doesn’t ground the distribution block.

Anyway- just a thought. Best of luck.