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Non-Snake Oil Power/Line Conditioner?

SuicideSquid

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Hi All,

I've got two separate issues going on right now, in my office/home studio space and in my living room/home theatre space.

The first, in my home theatre - I have a gaming PC hooked up to my surround system and TV, which I use regularly. When plugged in normally, there's a weird high-pitched whine that's clearly audible from the rear and surround speakers any time I move the mouse.

After a ton of futzing about (with help from some folks here) I found a temporary solution: Break the earth pin off the power cable from the PC, and the noise is gone. So clearly there's some kind of noise passing through the common ground, but I'd prefer not to rely on this as the long-term solution.

The second, in my home studio, is an odd intermittent high pitched clicking that's picked up by my more sensitive mics and single-coil pickup guitars. I haven't found a solution to this problem yet - I think it might actually be the AC adapter for my Focusrite audio interface creating the sound but I'm not 100% sure yet.

I believe a good power conditioner ought to fix the first problem, and might fix the second one. I picked up an inexpensive rack mount ART PB4x4+USB power conditioner. It reduced, but did not eliminate, the mouse buzz, and made no impact on the home studio problem. It also produces quite a bit of audible noise itself, so I'm returning it.

Any suggestions for a reasonably priced non snake oil power conditioner that might completely eliminate the computer/mouse issue in my home theatre (and may as a bonus clean up the home studio issue)?
 
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staticV3

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Any suggestions for a reasonably priced non snake oil power conditioner that might completely eliminate the computer/mouse issue in my home theatre
How is your PC hooked up to your home theater? Via an AVR?
If so, which AVR? And with what kind of cable?
 

stubaggs

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Hi All,

I've got two separate issues going on right now, in my office/home studio space and in my living room/home theatre space.

The first, in my home theatre - I have a gaming PC hooked up to my surround system and TV, which I use regularly. When plugged in normally, there's a weird high-pitched whine that's clearly audible from the rear and surround speakers any time I move the mouse.

After a ton of futzing about (with help from some folks here) I found a temporary solution: Break the earth pin off the power cable from the PC, and the noise is gone. So clearly there's some kind of noise passing through the common ground, but I'd prefer not to rely on this as the long-term solution.

The second, in my home studio, is an odd intermittent high pitched clicking that's picked up by my more sensitive mics and single-coil pickup guitars. I haven't found a solution to this problem yet - I think it might actually be the AC adapter for my Focusrite audio interface creating the sound but I'm not 100% sure yet.

I believe a good power conditioner ought to fix the first problem, and might fix the second one. I picked up an inexpensive rack mount ART PB4x4+USB power conditioner. It reduced, but did not eliminate, the mouse buzz, and made no impact on the home studio problem. It also produces quite a bit of audible noise itself, so I'm returning it.

Any suggestions for a reasonably priced non snake oil power conditioner that might completely eliminate the computer/mouse issue in my home theatre (and may as a bonus clean up the home studio issue)?
I had a similar issue, this adapter worked for me - Morley Hum Exterminator
 

Mikig

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I would proceed like this:

free things first!!
- check the general ground and whether all sockets are earthed.
- check whether the power strips you have are in good condition.
- try to phase all the devices, following the power from the wall socket with multiple socket extensions and devices.
- check that there are no neon lights, lamps with transformers, or other "noisy" appliances on the electrical line that carries power to the devices
- check that there are no sources of "radio" noise.

If nothing changes I would try looking at filtered mains conditioners.
I abandoned them, and built a dedicated power line, with very little money. Excellent result.
 
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SuicideSquid

SuicideSquid

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How is your PC hooked up to your home theater? Via an AVR?
If so, which AVR? And with what kind of cable?
It's hooked up to a Denon AVR-X4700H via HDMI. I've tried an optical HDMI cable and it did not fix the issue. Trust me, I went through everything a few months ago when I was first diagnosing the issue. it's bizarre, but somehow the noise from the mouse (or the GPU redrawing the mouse cursor) is making its way to the AVR via ground. It's not the electrical in the house, everything is brand new, I've tried connecting on the same outlet, on different outlets, using regular HDMI, optical HDMI, different HDMI inputs on the receiver, physically moving the PC so it's 10' away from the receiver, the only thing that works is breaking off the earth pin.
 

MaxwellsEq

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After a ton of futzing about (with help from some folks here) I found a temporary solution: Break the earth pin off the power cable from the PC, and the noise is gone
Please put the earth pin back, restoring the safety earth of the PC for fire and electrocution avoidance!
 

Waxx

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the best power conditioner is still a simple double conversion UPS, where the device connected to it is fed by the battery of the ups, that is loaded from the net on the other side. The power is very clean, but you loose some power due to how it works. That UPS must have at least double the power capacity than the device is pulling from it to work good.

But very often a simple RFI/EMI filter can do the job also (and they are cheap). Most modern devices have that build in in the power supply.
 
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SuicideSquid

SuicideSquid

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Please put the earth pin back, restoring the safety earth of the PC for fire and electrocution avoidance!
That is precisely why I am asking for a recommendation for a power conditioner.
 
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SuicideSquid

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Power conditioners do not fix ground loop problems. They protect against over voltage and RFI/EMI problems.
There maybe an improvement, but they are not a complete solution.
I'm not convinced it's a ground loop problem, rather it seems to be EMI being transmitted over the common ground, which is a different issue. As noted above, I've tried ensuring all devices in the home theatre are plugged into the same (good quality) power bar that reports proper grounding, and tried isolating the PC on its own circuit, as well as physically isolating the PC from the other devices, and isolating HDMI by using an (expensive) optical cable, none of which fixes the issue.

The PC is one I built myself, and with a Ryzen 3600 CPU in an Asrock motherboard, a GeForce 4070 Ti graphics card, and 750 watt evga SFF power supply. The motherboard and processer are about four years old, the GPU and power supply are less than 18 months old.

A couple of the more curious things about the problem - the noise is isolated to the surround/height channels. My Denon receiver powers those. The front channels use the Denon as a preamp but are powered by a Buckeye hypex 6-channel amp, and do not pick up the noise. In addition, if I run my PC HDMI out into the television first and rely on eARC to get sound to the receiver, the issue goes away; however, I also lose Atmos support if I do this so it's not an ideal problem. This initially lead me to believe the noise was being transmitted with some kind of loop between the receiver and PC involving the HDMI cable, but switching to an optical HDMI cable didn't fix the problem.
 

Zimmerframe

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Is it a wireless or usb mouse ?

Have you tried a different mouse ?

Does it do it if you move the cursor using the keys instead of the mouse ? ie, enable the "Mouse keys" (Start/Control Panel/Ease of Access/Make mouse easier/enable mouse keys).
 

audio_tony

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@SuicideSquid The AVR is double insulated and as such has no mains earth connection.

What happens if you disconnect the HDMI from the TV - does the noise persist?

Does the TV have a "figure of eight" type mains inlet? Have you tried rotating it? (effectively switching live & neutral).

Switching mains polarity as above can reduce common mode noise, which might be part of the problem.
 
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SuicideSquid

SuicideSquid

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Is it a wireless or usb mouse ?

Have you tried a different mouse ?

Does it do it if you move the cursor using the keys instead of the mouse ? ie, enable the "Mouse keys" (Start/Control Panel/Ease of Access/Make mouse easier/enable mouse keys).
Yes and yes. The noise is almost certainly caused by the GPU redrawing the cursor, not by the mouse itself. If I play GPU-intensive games there are other noises as well, the mouse movement is just the easiest to test as it happens at the desktop immediately after booting and doesn't require me to do other stuff to make it happen.

@SuicideSquid The AVR is double insulated and as such has no mains earth connection.

What happens if you disconnect the HDMI from the TV - does the noise persist?

Does the TV have a "figure of eight" type mains inlet? Have you tried rotating it? (effectively switching live & neutral).

Switching mains polarity as above can reduce common mode noise, which might be part of the problem.
I don't think the noise is related to the TV, as if I route HDMI through the TV noise goes away. I don't believe TV polarity can be reversed but I will check this evening.
 

audio_tony

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Yes and yes. The noise is almost certainly caused by the GPU redrawing the cursor, not by the mouse itself. If I play GPU-intensive games there are other noises as well, the mouse movement is just the easiest to test as it happens at the desktop immediately after booting and doesn't require me to do other stuff to make it happen.
I've had a similar issue back in the 90's (with a built in sound card!) but I can't recall anything similar over the past 15 years or more.

I wonder if it's a motherboard related issue?

It would be useful if you had access to another PC of similar spec (but with a different motherboard and Intel CPU) to see if the same issue occurs.

Having said that, the most common issue for me has always been ground related, but I have had the occasional noisy motherboard.
 
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SuicideSquid

SuicideSquid

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I've had a similar issue back in the 90's (with a built in sound card!) but I can't recall anything similar over the past 15 years or more.

I wonder if it's a motherboard related issue?

It would be useful if you had access to another PC of similar spec (nut with a different motherboard and Intel CPU) to see if the same issue occurs.

Having said that, the most common issue for me has always been ground related, but I have had the occasional noisy motherboard.
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).
 

MaxwellsEq

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Yes and yes. The noise is almost certainly caused by the GPU redrawing the cursor, not by the mouse itself. If I play GPU-intensive games there are other noises as well, the mouse movement is just the easiest to test as it happens at the desktop immediately after booting and doesn't require me to do other stuff to make it happen.


I don't think the noise is related to the TV, as if I route HDMI through the TV noise goes away. I don't believe TV polarity can be reversed but I will check this evening.
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.
 
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