[Povell42]

I cannot figure out why I have PC audio noise in my speakers when using a per-out amp. So, I have an HDMI coming out of my GTX 1080 graphics card into my LG C9 TV/Monitor. I then have an arc/earc HDMI on my TV going to my Yamaha TSR-700 receiver. When I have my speakers (RP-600) hooked up to the TSR-700... all is well. As soon as I use the pre-outs from the TRS-700 to my external amp (Behringer A-800, and plug my speakers in to the A-800.... their is computer noise coming out of my speakers. Literally, as things happen on my computer screen (like moving a window around) it generates noise that is audible from my speakers. This same thing happened on an older Receiver I had when using its per-outs to the external amp... so I know it is not the receiver pre outs having an issue.

As soon as I unplug the HDMI that is going into my receiver from the TV - or unplug the pre-outs going into the A-800 amp - there is no noise. I have been so confused by this... and again, as soon as I plug my speakers directly into the receiver there is not noise or issues.

I really would like to power the speakers by the the receiver pre-out to A-800 amp, as it has a lot more power.

Also, when I use a fiber optic cable out from the TV the the Receiver, there is no noise when using the pre-outs. As soon as I plug the hdmi from the TV into the receiver, there is noise regardless of input or audio source selection from the receiver..... the receiver can even be tuned off, and the noise is still there.

Any ideas? Or others with is issue? I know I can just eliminate the A-800 amp, but I would really like to use it, as it has balanced inputs too that I would like to use it via a separate Balanced DAC... this way I have the same speakers hooked up to a HIFI music setup, and a home theater surround sound set up. Hopefully this makes since, as it is kinds hard to describe via text.

(SEE ATTACHED DIAGRAM)

ANY SUGGESTIONS/ADVICE would be appreciated. Thanks!

 

[technobear]

Use the optical cable.

 

[Povell42]

Use the optical cable.

That is what I did with my older theater setup/Receiver, but Optic Cable does not pass threw Dolby Atmos and it only allows the PC signal to be in Stereo. One reason I spent so much money for a new setup was to use the same surround system for PC games (and it works.... just with the stupid PC noise ).

Also, I have to have my Receiver hooked up to the TV via HDMI for my other AV components, so just unplugging the HDMI from the receiver isn't an option for me.

Isn't it odd that PC noise is introduced into the signal when adding the A-800 as the pre-out external amp, or having the HDMI from the TV into my receiver? Unplugging the HDMI from the TV or when I power down my PC, the noise stops.

I fully understand some solutions are to just ditch the A-800, or us Optic Cable only from the TV a and turn off hdmi arc in the TV and buy an external streaming device instead of using earc from the TV..... BUT, technically what I am doing should work fine, and it is boggling my mind why this annoying PC noise is introduced when having my PC plugged into my TV/monitor, and using the pre-out on a receiver for external amping.

But I am hoping that someone reads this who has experience this themselves, or can recreate the issue, or has a reason as to why this is happening.

Oh, and also, everything is plugged into the same power source so no noise loops should be present. And my power source has 3 banks and power cleaning happening.

 

[technobear]

The noise travels on the ground. If this were a USB connection, I would recomment an iGalvanic3.0. I don't know if a similar device exists for HDMI. I suspect not.

Your receiver is obviously immune to it but the A-800 is not.

 

[Povell42]

The noise travels on the ground. If this were a USB connection, I would recomment an iGalvanic3.0. I don't know if a similar device exists for HDMI. I suspect not.

Your receiver is obviously immune to it but the A-800 is not.

Thanks for the reply,
So, you think the ground noise is coming from the PC or GTX1080 itself right? This should not be a ground loop issue as all devices are plugged into the same power source (Panamax MR5100).

I only see some HDMI 2.0B audio extractors not a noise isolator. I would give it a try, but I am using HDMI 2.1 cables to be able to play games @ 1440p 120hz w/HDR, and my HDMI 2.0b cables fail at that. Plus as soon as RTX 3080 can be bought without dedicating my life to buying one.... I will definitely need the HDMI2.1 .

 

[technobear]

You said in your first post that the noise relates to things happening on the PC. Therefore it is PC generated noise. It will be imprinted on the power or ground wires of the HDMI. By using the optical link from the TV, you break that path to your power amp. I can't find the amp topology for the Yamaha but I see that the Behringer is a Class D design. The USB problem I had also involved a Class D power amp. The ground noise had no effect at all on the intervening DAC (an RME). It caused all sorts of burbles and whistles and whining to come from the power amp though.

On paper at least, the A-800 doesn't appear to be any more powerful than the Yamaha anyway (or are you mono'ing two of them?)

Here is something that might solve the problem:

https://www.amazon.co.uk/AV-Link-Gr...ca+ground+loop+isolator&qid=1617519227&sr=8-3

Cheap enough to try.

 

[PurpleAngel]

How about running HDMI from the PC to the TSR-700, then HDMI from the TSR-700 to the TV.
No need to connect the PC directly to the TV.

 

[Povell42]

How about running HDMI from the PC to the TSR-700, then HDMI from the TSR-700 to the TV.
No need to connect the PC directly to the TV.

I have tried that too. Same thing happens. As soon as I have any path from my graphics card to the receiver via direct or through the TV hdmi, it creates the noise.

But here is an update on my progress:
I purchased an XtremPro Hi-end Ground Loop Noise Isolator/Filter from Amazon. I placed it between the pre-out from the receiver and the amp. It takes away all the variable noise from the PC, but there is still a softer hum, which I think I can live with. I can still easily hear it when the room is quiet, but with stuff playing its not really noticable.

My other idea is to get a good preamp. That way I can select the source I want to play only and I can activate the pre-out from my Receiver only when I want surround sound via the preamp input source. That way I can use my balanced Dac to preamp then to my amp and hopefully it breakes the rca connection and eliminates the hum when listening to Stereo music. I really want the Schiit Freya Plus. I think that mechanically switches the input source to the amp.

 

[PurpleAngel]

I have tried that too. Same thing happens. As soon as I have any path from my graphics card to the receiver via direct or through the TV hdmi, it creates the noise.

But here is an update on my progress:
I purchased an XtremPro Hi-end Ground Loop Noise Isolator/Filter from Amazon. I placed it between the pre-out from the receiver and the amp. It takes away all the variable noise from the PC, but there is still a softer hum, which I think I can live with. I can still easily hear it when the room is quiet, but with stuff playing its not really noticeable.

My other idea is to get a good preamp. That way I can select the source I want to play only and I can activate the pre-out from my Receiver only when I want surround sound via the preamp input source. That way I can use my balanced Dac to preamp then to my amp and hopefully it breakes the rca connection and eliminates the hum when listening to Stereo music. I really want the Schiit Freya Plus. I think that mechanically switches the input source to the amp.

Try getting a few cheap surge protectors and switch a few devices over to the surge protectors.
Plug the surge protectors into different wall sockets thru out the room.
See if anything changes.

 

[jiiteepee]

Isn't it odd that PC noise is introduced into the signal when adding the A-800 as the pre-out external amp, or having the HDMI from the TV into my receiver? Unplugging the HDMI from the TV or when I power down my PC, the noise stops.

Does the A-800 have two mono inputs with three different input connector types/channel or is it possible to input two or three stereo sources at once (now you do two at once right?)?

 

[Povell42]

Does the A-800 have two mono inputs with three different input connector types/channel or is it possible to input two or three stereo sources at once (now you do two at once right?)?

The A800 has two inputs; one R/L balanced (XLR) input, and one L/R RCA input. It will play both of them at the same time if I have to two sources playing (which I do not do). I have the PC output via optic cable into my ENOG DAC with balance output into the A800 balance input. And the TV's earc HDMI plugged into the receiver with the Front L/R pre-out hooked up to the A800 via RCA.

I guess my current issue now is that I have the noise filter between the Receiver and Amp with the constant hum, I needed to turn the A800's volume down to soften the hum. Now the Receiver needs to max out the Front R/L channel Levels and lower the other channels to have them match volume levels, limiting the system and now I have to crank the volume up in the receiver. Which makes the external amp pointless in the atmos setup... But I use the PC ENOG DAC to Amp daily to listen to music. (First world problems, I know).

 

[Povell42]

Try getting a few cheap surge protectors and switch a few devices over to the surge protectors.
Plug the surge protectors into different wall sockets thru out the room.
See if anything changes.

I have two expensive surge protector/power cleaners plugged into to same outlet, as I read that if I plug them into 2 different outlets on the same breaker, that it can cause ground loop noise.
But I will see if plugging stuff into different plugs helps and let you know. Thanks for the suggestion.

 

[PurpleAngel]

I have two expensive surge protector/power cleaners plugged into to same outlet, as I read that if I plug them into 2 different outlets on the same breaker, that it can cause ground loop noise.
But I will see if plugging stuff into different plugs helps and let you know. Thanks for the suggestion.

Nothing wrong with plugging the surge protectors into separate wall outlets, ground loops are more likely to happen when the surge protectors are plugged into the same wall outlet, so try different wall outlets.

 

[mimart7]

This may be of help:

https://www.jensen-transformers.com/home-theater/

 

[Zurv]

Is it always or when the GPU is under load? (or get louder under load.)
It might be coil whine impacting audio. Try putting some Ferrite Cores on the PCI-E cables were they are connected to the 1080.
they are cheap to try: https://www.amazon.com/gp/product/B01E5E5IY4/

This is a overclocker trick when a power or volt mod (of the GPU) causes noise going out via HDMI.
One of my 3090s has this problem and the cores helped a ton... i still might replace it if there is every stock. ugh.

i used to use them on my 1080s
(very old timespy pix)