Qudelix 5k as input for 8010?

[MKreroo]

So I hooked up the MTMs with the 5K. For some reason connecting to USB gives distortion (using a 1/8 to 2 1/4 splitter).
No issue when running the 5K on battery and BT with the same cable.
Do you have any ideas for the cause?

I did a bit of troubleshooting and this only occured when it's connected to PC USB port, no problem if the USB port is connected to a charger and through BT.

Edit: seems to be ground loop, as the charger brick I used has no ground pin.

 

[rnd]

So I hooked up the MTMs with the 5K. For some reason connecting to USB gives distortion (using a 1/8 to 2 1/4 splitter).
No issue when running the 5K on battery and BT with the same cable.
Do you have any ideas for the cause?

I did a bit of troubleshooting and this only occured when it's connected to PC USB port, no problem if the USB port is connected to a charger and through BT.

You said "distortion" but I'm assuming you are hearing general noise, even when not playing any sounds? If so, you may be experiencing a ground loop. In my setup, I had a similar issue, and the noise also went away when playing over BT from battery (but it got worse for me when powering from a cheap IKEA charger).

Anyway, if the noise is there when plugged into USB but goes away over BT, then a good USB isolator will likely help. I used this one https://www.olimex.com/Products/USB-Modules/USB-ISO/ recommended by another forum member, and it's dead silent now.

Before spending any money, you may try unplugging everything from your PC, and only plugging in the Qudelix. If there's no noise in that configuration, try re-introducing your PC peripheries one by one. In my case, it was the HDMI cables to the screens that caused the noise to come back in. Since I can't do without my screens and didn't have any better ideas, I got the USB ISO and it solved my problem.

 

[MKreroo]

You said "distortion" but I'm assuming you are hearing general noise, even when not playing any sounds? If so, you may be experiencing a ground loop. In my setup, I had a similar issue, and the noise also went away when playing over BT from battery (but it got worse for me when powering from a cheap IKEA charger).

Anyway, if the noise is there when plugged into USB but goes away over BT, then a good USB isolator will likely help. I used this one https://www.olimex.com/Products/USB-Modules/USB-ISO/ recommended by another forum member, and it's dead silent now.

Before spending any money, you may try unplugging everything from your PC, and only plugging in the Qudelix. If there's no noise in that configuration, try re-introducing your PC peripheries one by one. In my case, it was the HDMI cables to the screens that caused the noise to come back in. Since I can't do without my screens and didn't have any better ideas, I got the USB ISO and it solved my problem.

Interesting, thanks for the tip. I have looked into USB ISO earlier when I read about similar issue for something else.
I will try the peripheral trick and see how it goes (though I suspect an isolator is unavoidable)

I also want to ask, if I were to be using something like Topping D10 instead, since it's also USB powered, how does it prevent ground loop?

 

[solderdude]

So I hooked up the MTMs with the 5K. For some reason connecting to USB gives distortion (using a 1/8 to 2 1/4 splitter).
No issue when running the 5K on battery and BT with the same cable.
Do you have any ideas for the cause?

I did a bit of troubleshooting and this only occured when it's connected to PC USB port, no problem if the USB port is connected to a charger and through BT.

Edit: seems to be ground loop, as the charger brick I used has no ground pin.

Yes, very likely a groundloop issue.

mains leakage laptop charger -> laptop -> via USB shield/ground into audio ground -> into the speakers -> inside the speakers audio ground is connected to safety ground and that's the loop.... mains via audio ground back to mains.

Maybe you can lower it by connecting the mains to the speakers via an extension cord that has no groundpin.
I would suggest to use an USB isolator. Most of these will limit the maximum samplerate though but there are those that don't.

Any other DAC might well do the same. D10 also has USB connected to audio ground and is not connected to safety ground either.

 

[MKreroo]

Yes, very likely a groundloop issue.

mains leakage laptop charger -> laptop -> via USB shield/ground into audio ground -> into the speakers -> inside the speakers audio ground is connected to safety ground and that's the loop.... mains via audio ground back to mains.

Maybe you can lower it by connecting the mains to the speakers via an extension cord that has no groundpin.
I would suggest to use an USB isolator. Most of these will limit the maximum samplerate though but there are those that don't.

Any other DAC might well do the same. D10 also has USB connected to audio ground and is not connected to safety ground either.

Thanks, I looked around a bit more and came to final conclusion that it is ground loop indeed.
PC and speakers are on the same power strip, I have heard (seen) some saying that a separate strip would help, but some also saying that makes it worse.
Speaking of USB isolator, so far what I can find, the best one seems to be HS01 from Topping, which Archimago also reviewed here, but damn is it expensive.......
Luckily, sampling rate and bit shouldn't be much of an issue since the 5K is limited to 24/96 anyway.

 

[solderdude]

https://www.amazon.ca/Nobsound-Isolator-Eliminator-Industrial-Protection/dp/B07RZSC1Y2/ref=sr_1_3?crid=12LTS7OZDY40A&keywords=USB+isolator&qid=1664432233&qu=eyJxc2MiOiI0LjMzIiwicXNhIjoiMy43NiIsInFzcCI6IjMuMDIifQ%3D%3D&s=electronics&sprefix=usb+isolator%2Celectronics%2C223&sr=1-3

https://www.amazon.ca/DSD-TECH-SH-G01A-Isolator-ADUM3160/dp/B093LKN3YH/ref=sr_1_6?crid=12LTS7OZDY40A&keywords=USB+isolator&qid=1664432295&qu=eyJxc2MiOiI0LjMzIiwicXNhIjoiMy43NiIsInFzcCI6IjMuMDIifQ%3D%3D&s=electronics&sprefix=usb+isolator%2Celectronics%2C223&sr=1-6

These should be able to do max 24/96.