Ground Loop (pls don't hurt me)

[Snowej]

G'day fellas, I read through the 'has this already been discussed' threads and it has, but not necessarily in regards to my scenario.

Basically I have a PC with a high powered GPU a.k.a. RTX 3080 (might be important) with a Topping D10 DAC connected via USB (USB acts as power/data), via RCA to a XDUOO MT-602 tube amp, connected to my headphones. They're all connected to the same power strip (8 plugs). The devices connected are:

• Computer (CPU: 5700X3D, GPU: RTX 3090, the rest is pretty standard)
• Monitor (IPS-LCD)
• Monitor (OLED)
• TV (VA-LCD)
• Amp (XDUOO MT-602)
• Phone charger (65W)
• Pedestal fan

I am experiencing what seems to be a ground loop, specifically one caused by my graphics card if the video by FireWalk on YouTube is anything to go by. I hear the same sound described in the video. When I unplug my DAC from my amp, I cannot hear any noise at all.

I recently purchased 4 separate noise filters/hum destroyers (I'm going crazy) from Amazon, and I've only tested one of them so far -- which DID work in removing the noise. They are all very similar, a little box with RCA input and output, some are smaller boxes with cables, others are larger boxes without cables. I've only tried one with a small box that has input and output cables, which are connected as so:

PC > DAC > RCA > hum destroyer > amp > headphones

The one that I tried did technically reduce the hum (it completely removes the noise), however, it also affects the sound quality, specifically worse bass, and frankly overall it just sounds noticeably worse. It also has a lower dB (I have not measured it, but the volume knob is able to go significantly higher).

I also have an ifi Defender+ coming in the mail, which goes before the USB cable instead of between the RCA cables. Before I open that one, what is the likelihood that it will fix the issue without degrading sound quality?

And if all these devices cannot fix the issue without degrading sound quality, what the hell am I even doing?? I just want to listen to music without that terrible hum.

I plead to you all, please please please help me remove this terrible hum. It's destroying my life.

Thank you.

 

[suttondesign]

Don't I know it. I really think you need to find a way to use balanced connections to your cans. I've had to replace Topping unbalanced DACs with balanced ones for that precise reason!

 

[solderdude]

The Topping D10 DAC is notorious for ground loops.
The Digital-analog ground connection in the DAC is below par.

All you probably need is an USB isolator.
pick the somewhat more expensive ($ 30.-) 480Mbs USB Isolator with High-Speed ADI ADUM3165 Chip
(not the cheap 1.5-12Mbs)

 

[Timcognito]

Does your dac accept toslink/optical from your computer. Very inexpensive and easy to try.

 

[respice finem]

I was able to eradicate a similar problem with this:

DSD TECH SH-G01B USB Isolator with High Speed ADI ADUM3165 Chip - 480Mbps: Amazon.de: Business, Industry & Science

DSD TECH SH-G01B USB Isolator with High Speed ADI ADUM3165 Chip - 480Mbps: Amazon.de: Business, Industry & Science

www.amazon.de

 

[Snowej]

Don't I know it. I really think you need to find a way to use balanced connections to your cans. I've had to replace Topping unbalanced DACs with balanced ones for that precise reason!

I was really hoping I wouldn't have to replace anything, which is ironic since I've spent so much trying to fix the problem. But ironically, I didn't have the info to fix it with in the first place.

 

[Snowej]

Does your dac accept toslink/optical from your computer. Very inexpensive and easy to try.

Instead of simply checking my DAC (it's a bit awkward) I asked Goggle AI if my DAC accepted toslink, and he said yes. In reality, it only does toslink out... Add that to my waste of money (USB to toslink cable, plus toslink cable)... Sigh...

 

[Snowej]

The Topping D10 DAC is notorious for ground loops.
The Digital-analog ground connection in the DAC is below par.

All you probably need is an USB isolator.
pick the somewhat more expensive ($ 30.-) 480Mbs USB Isolator with High-Speed ADI ADUM3165 Chip
(not the cheap 1.5-12Mbs)

Ironically I did get the DSD TECH Isolator, but since I'm in Australia, I didn't have access to the one you listed, so I got the worse option.....

 

[solderdude]

It is only worse when you want to play DSD files and > 192/24 files otherwise it will be fine.
Could also be that the internal DCDC converter can not power the D10 well enough.

 

[Snowej]

It is only worse when you want to play DSD files and > 192/24 files otherwise it will be fine.
Could also be that the internal DCDC converter can not power the D10 well enough.

I ordered the DSD TECH SH-G01A USB Isolator with ADUM3160 Chip 12M (Blue) which is the lesser version of what you described, and which requires significantly more dB to listen to music. I literally just opened it because you recommended it. It ain't what I'm used to.

 

[AnalogSteph]

Then possibly you got a bad one with a weak power supply or something... I can't really imagine that a D10 would be using more than 200 mA. There should be no change in sound between using the isolator or not doing so. If it caused the unit to be redetected, maybe check the settings.

 

[respice finem]

Maybe a stupid remark, sorry, but, if working with cable extensions, it is not impossible to plug an isolator in the wrong direction.
The male part of the isolator goes into the PC, but the isolator is too bulky, so an extension is needed...

 

[Snowej]

Then possibly you got a bad one with a weak power supply or something... I can't really imagine that a D10 would be using more than 200 mA. There should be no change in sound between using the isolator or not doing so. If it caused the unit to be redetected, maybe check the settings.

The D10 doesn't have a power supply, it runs off USB power. Unless you mean there's an internal power supply powered by the USB? I'm not too familiar with how these things are built, sorry.

I've tried 3 isolators now:

1. TEKERA RCA Ground Loop Isolator (it's available on Amazon.com.au) - RCA in and out, not powered
2. DSD TECH SH-G01A USB Isolator with ADUM3160 Chip 12M - USB dongle, not powered
3. ifi iDefender+ - USB dongle with 5v power supply

All 3 of them removed the ground loop noise, however, they also reduced the volume pretty significantly. Can't test to see the exact dB, but on my xDuoo MT-602 without any of these devices, volume knob is typically at around 12 o'clock. With all these devices it's closer to 2 - 3 o'clock.

Devices 1 and 2 noticeably reduced audio quality too, specifically sub bass was missing. They're unusable for me.

The ifi iDefender+ kind of sounds off as well (not as bad as the 2 above). I need to test it properly though, as I just got it today. Need to volume match it as best as I can.

I'm using Equalizer APO, so every time I plug the DAC in again, I always check the device selector to make sure the DAC is selected, and all the volume is at 100% in my system. Everything looks the same.

Maybe a stupid remark, sorry, but, if working with cable extensions, it is not impossible to plug an isolator in the wrong direction.
The male part of the isolator goes into the PC, but the isolator is too bulky, so an extension is needed...

They're all working, and I've tried a bunch of USB slots. The rear I/O and a USB hub. They're all doing their job in getting rid of the noise, but seemingly adding more issues.

 

[Snowej]

With the iDefender+, I just heard other noises. hard to describe, like when you used to leave your mobile phone next to a radio and it did that galloping noise, except it's the part at the end. And it was very very brief.

Still, it's more noise.

 

[Sokel]

The D10 doesn't have a power supply, it runs off USB power. Unless you mean there's an internal power supply powered by the USB? I'm not too familiar with how these things are built, sorry.

I've tried 3 isolators now:

1. TEKERA RCA Ground Loop Isolator (it's available on Amazon.com.au) - RCA in and out, not powered
2. DSD TECH SH-G01A USB Isolator with ADUM3160 Chip 12M - USB dongle, not powered
3. ifi iDefender+ - USB dongle with 5v power supply

All 3 of them removed the ground loop noise, however, they also reduced the volume pretty significantly. Can't test to see the exact dB, but on my xDuoo MT-602 without any of these devices, volume knob is typically at around 12 o'clock. With all these devices it's closer to 2 - 3 o'clock.

Devices 1 and 2 noticeably reduced audio quality too, specifically sub bass was missing. They're unusable for me.

The ifi iDefender+ kind of sounds off as well (not as bad as the 2 above). I need to test it properly though, as I just got it today. Need to volume match it as best as I can.

I'm using Equalizer APO, so every time I plug the DAC in again, I always check the device selector to make sure the DAC is selected, and all the volume is at 100% in my system. Everything looks the same.



They're all working, and I've tried a bunch of USB slots. The rear I/O and a USB hub. They're all doing their job in getting rid of the noise, but seemingly adding more issues.

Probably your USB ports don't have enough juice to power both the isolator and the DAC at the 1 and 2.
Does any of them run hot?

A powered isolator may helped there (no, iFi is not a proper isolator )

 

[Snowej]

Probably your USB ports don't have enough juice to power both the isolator and the DAC at the 1 and 2.
Does any of them run hot?

A powered isolator may helped there (no, iFi is not a proper isolator )

Yeah I'm thinking that's correct with the first two.

Now back to the iDefender+, I actually got to test it a bit more now that I had some free time and I think I was hallucinating the reduced sound quality and volume reduction on this one. It's way better than the above two options (always was), but the slight reduction in sub bass that I thought I noticed is most likely not there.

I do hear a very brief new noise here and there like I mentioned above, but only if nothing is playing and they're very few and far between. It's definitely something I can live with.

This entire ordeal has been a living hell, I could have just got a new DAC with optical input for the money I've spent. I'll try return all the other stuff that didn't work, but now I've also got a Topping L30ii amp coming (because I also have a Schiit Fulla 2 that didn't have ground loop, so I thought it was amp related). Ah well, the price of troubleshooting hifi audio from scratch (and very poorly I might add).