Electrical Interference in PC Audio Chain Linked to GPU Load – Need Advice

[BeeInMyHead]

Current Audio Chain (source to destination):
PC -> USB to USB-C Adapter -> USB-C to Micro-USB cable (included) -> Tempotec Sonata HD Pro DAC dongle
-> Long audio cable -> S.M.S.L SP200 Amp
-> Long audio cable -> HIFIMAN Sundara

Issue:
I experience significant electrical noise/interference under the following conditions:

• Plugging USB adapter into motherboard USB ports (high severity)
• Plugging USB adapter into front panel USB ports on the case (high severity)
• Directly connecting the amp via audio cable to motherboard/case audio jacks without DAC (extremely high severity)
• Connecting amp directly to monitor's audio out without DAC dongle (low-medium severity)

The interference rises by magnitudes whenever my GPU ramps up (GPU has coil whine).


Observations:

• The issue significantly improves (almost disappears) when connecting my amp via the monitor's audio output, hinting that physical distance or isolation from the PC helps.
• Using the external DAC dongle reduces the issue noticeably compared to directly using motherboard audio output.
• Connecting the amp through the DAC dongle to my laptop or smartphone results in no interference. AMP and DAC do their job well in other scenarios.

Solutions?:

1. Distance of DAC conversion?: Perhaps a longer USB cable in between the DAC and the USB adapter connected to the motherboard might help. Unfortunately I can't plug the DAC dongle into my monitor to test this slightly.
2. Ground loop or improper grounding/shielding: I've considered grounding or shielding but everyone online seems to have different solutions for this and there don't seem to be easy answers..
3. DAC replacement: external desktop DAC instead of a dongle might fix the issue. But I feel like that is just solution No.1 wrapped up nicely.
4. Balanced cable?: I don't know if this will fix things but maybe? But I wonder if this will only mask the issue or if it will truly fix it perfectly.

Any suggestions on what will fix this? I don't want to buy a million things. Surely there is an easy and obvious solution to this that doesn't involve spending the equivalent of a new DAC and a dozen cables... right?

EDIT: Actually now that I think of it maybe it isn't the distance and really a grounding issue? Because the monitor has its own power supply. So maybe that somehow impacts things? Still unsure though.

EDIT2: Issue is the same if PC and SMSL Amp have different power outlets compared to putting them onto the same strip.

 

[staticV3]

Hi @BeeInMyHead! Welcome to ASR.

Any suggestions on what will fix this?

A USB Isolator between PC and Sonata HD.

E.g:
Topping HS01
Hifime High-Speed USB Isolator v2
JDS Synapse
Neutron HiFi Isolator V1
DSD TECH SH-G01L
Olimex USB-ISO-HS
...

Edit:
Alternatively, replacing the Sonata with a DAC that has Toslink input (e.g. SU-1, PS200), then connecting the DAC to your PC via Toslink.

Either solution would prevent interference noise from the PC.

 

[BeeInMyHead]

Hi @BeeInMyHead! Welcome to ASR.


A USB Isolator between PC and Sonata HD.

E.g:
Topping HS01
Hifime High-Speed USB Isolator v2
JDS Synapse
Neutron HiFi Isolator V1
DSD TECH SH-G01L
Olimex USB-ISO-HS
...

Edit:
Alternatively, replacing the Sonata with a DAC that has Toslink input (e.g. SU-1, PS200), then connecting the DAC to your PC via Toslink.

Either solution would prevent interference noise from the PC.

Do all USB isolators leave the source signal completely untouched?
Also how exactly does this work? I thought there is error correction going on in the digital signal? Or is that not the case? (Maybe the dac and the amp don't do anything? I have no clue how it works.)
I was under the impression that any noise introduced at the digital stage of the transfer will just be ignored due to error correction.

EDIT:
I looked up how they work and I might get one. Though they seem pricey. Does every isolator do an equally good job or do they somehow change the signal?

EDIT2:
But before I resort to one of those: will a balanced cable between the dac and amp work? Those are a lot cheaper I feel like.
Nevermind I didn't think about how to even connect it to the dac. I don't know if thats even possible. So yeah. Might need to go with your suggestion.

Thanks

 

[staticV3]

Do all USB isolators leave the source signal completely untouched?

Yes.

Also how exactly does this work?

Tiny transformers.

I was under the impression that any noise introduced at the digital stage of the transfer will just be ignored due to error correction.

Error correction can only correct errors in the digital signal.

Your motherboard and GPU OTOH emit analog interference noise, which travels along the ground and data wires and bleeds into the DAC's analog output.

Does every isolator do an equally good job

I have not seen a good test comparing isolators in a situation like yours, but I have yet to hear of an isolator failing to isolate interference noise, implying that they all work.

or do they somehow change the signal?

Again: they do not change the signal.

they seem pricey.

The last two on my list are rather affordable.

will a balanced cable between the dac and amp work?

Unlikely, but if you can solder and make your own cable to ensure a correct SE->Bal pinout for the SP200's differential input to function (most off-the-shelf SE->Bal cables don't), then I'd say it's worth a try.

 

[BeeInMyHead]

Yes.


Tiny transformers.


Error correction can only correct errors in the digital signal.

Your motherboard and GPU OTOH emit analog interference noise, which travels along the ground and data wires and bleeds into the DAC's analog output.


I have not seen a good test comparing isolators in a situation like yours, but I have yet to hear of an isolator failing to isolate interference noise, implying that they all work.


Again: they do not change the signal.


The last two on my list are rather affordable.


Unlikely, but if you can solder and make your own cable to ensure a correct SE->Bal pinout for the SP200's differential input to function (most off-the-shelf SE->Bal cables don't), then I'd say it's worth a try.
View attachment 445606 View attachment 445605

Do you think I can just buy a cheap usb isolator with an ADuM3165/ADuM4160 for example on aliexpress? Having trouble finding the ones you linked in Germany.
Otherwise I might just overpay a little bit and get it over with. Thank you

EDIT: I might have found one you mentioned at a good price. Will order it now.

 

[Chrise36]

Current Audio Chain (source to destination):
PC -> USB to USB-C Adapter -> USB-C to Micro-USB cable (included) -> Tempotec Sonata HD Pro DAC dongle
-> Long audio cable -> S.M.S.L SP200 Amp
-> Long audio cable -> HIFIMAN Sundara

Issue:
I experience significant electrical noise/interference under the following conditions:

• Plugging USB adapter into motherboard USB ports (high severity)
• Plugging USB adapter into front panel USB ports on the case (high severity)
• Directly connecting the amp via audio cable to motherboard/case audio jacks without DAC (extremely high severity)
• Connecting amp directly to monitor's audio out without DAC dongle (low-medium severity)

The interference rises by magnitudes whenever my GPU ramps up (GPU has coil whine).


Observations:

• The issue significantly improves (almost disappears) when connecting my amp via the monitor's audio output, hinting that physical distance or isolation from the PC helps.
• Using the external DAC dongle reduces the issue noticeably compared to directly using motherboard audio output.
• Connecting the amp through the DAC dongle to my laptop or smartphone results in no interference. AMP and DAC do their job well in other scenarios.

Solutions?:

1. Distance of DAC conversion?: Perhaps a longer USB cable in between the DAC and the USB adapter connected to the motherboard might help. Unfortunately I can't plug the DAC dongle into my monitor to test this slightly.
2. Ground loop or improper grounding/shielding: I've considered grounding or shielding but everyone online seems to have different solutions for this and there don't seem to be easy answers..
3. DAC replacement: external desktop DAC instead of a dongle might fix the issue. But I feel like that is just solution No.1 wrapped up nicely.
4. Balanced cable?: I don't know if this will fix things but maybe? But I wonder if this will only mask the issue or if it will truly fix it perfectly.

Any suggestions on what will fix this? I don't want to buy a million things. Surely there is an easy and obvious solution to this that doesn't involve spending the equivalent of a new DAC and a dozen cables... right?

EDIT: Actually now that I think of it maybe it isn't the distance and really a grounding issue? Because the monitor has its own power supply. So maybe that somehow impacts things? Still unsure though.

EDIT2: Issue is the same if PC and SMSL Amp have different power outlets compared to putting them onto the same strip.

If you own a laptop use that they have better shielded PSUs.

 

[BeeInMyHead]

If you own a laptop use that they have better shielded PSUs.

That's what I was doing but I just build myself a PC (and I need my audio to sound fine)

 

[BeeInMyHead]

Do you think I can just buy a cheap usb isolator with an ADuM3165/ADuM4160 for example on aliexpress? Having trouble finding the ones you linked in Germany.
Otherwise I might just overpay a little bit and get it over with. Thank you

EDIT: I might have found one you mentioned at a good price. Will order it now.

Actually I think I know the answer. Probably not because most of those don't provide power and aren't 480 Mbps. So I am guessing those will not recognize the sonata

 

[DVDdoug]

Do you think I can just buy a cheap usb isolator with an ADuM3165/ADuM4160 for example on aliexpress?

I believe so. The important thing is that the power & ground are isolated. The digital data lines usually aren't the problem but noise can be transferred into the analog circuitry through power & ground.

A "powered" USB hub with it's own power supply may be another solution. USB power from computers is notoriously noisy. (That's not a problem for the digital data which is highly-immune to noise.)

 

[BeeInMyHead]

Managed to buy myself a second hand DSD TECH SH-G01L. (because there are literally none for less than 42eur I can buy) Hope that works. Thanks for all the help.

 

[BeeInMyHead]

Managed to buy myself a second hand DSD TECH SH-G01L. (because there are literally none for less than 42eur I can buy) Hope that works. Thanks for all the help.

Okay so the DSD TECH SH-G01L practically fixed it. There is still some noise, but it is only audible if I turn the amp up and put it into high gain with no audio playing. (compared to my laptop where there is 0 audible noise)
But for my listening levels I can't hear it at all, so it is good enough for me.

Thanks for all the help again.