Help requested: USB noise issue with NUC8 ROCK and new Gustard X26 Pro

[Bcquinn]

Hi everyone. I’m a long-time ASR lurker, first-time poster, but am struggling with a new issue and am pretty sure it’s USB noise—and I don’t think I’m using a poorly designed DAC, but rather one recommended around these parts ; ).

I just got a Gustard X26Pro. I have a NUC 8 ROCK in a Turing case. Had been running that via USB to an Oppo BD105 and using that as my DAC, using the balanced XLR outs, and had no issues. I excitedly swapped in my Gustard yesterday, same connections as before with the Oppo, and I’m now getting low-level—but clearly there—beeping / data-type noises in the background (not a steady hum). They’re worse when I interact with Roon. I tried unplugging multiple items, switching outlets etc. and am fairly sure it’s the USB on my NUC creating the issue for these reasons:
- when I turn the PC off, or unplug the USB from the PC, but leave everything else on (e.g., rest of the chain primed to receive) the noise stops
- interestingly, with the PC on and USB plugged in, but the Gustard turned off (and even unplugged), and rest of the chain on, I still get the noise

Would welcome any thoughts on what the issue might be / am I diagnosing it correctly. I have an Intona isolator on the way; I’m hoping this will fix it.

 

[Hemi-Demon]

Are you sure you have the proper drivers for the NUC? Since its so new, the XU216 USB chip can cause issues with certain devices. Maybe consider a USB card dedicated for audio use inside the NUC. Also what version of windows are you using, that also could be the issue, if you are not on the latest Win10 version.

 

[Bullwinkle J Moose]

Are you sure you have the proper drivers for the NUC? Since its so new, the XU216 USB chip can cause issues with certain devices. Maybe consider a USB card dedicated for audio use inside the NUC. Also what version of windows are you using, that also could be the issue, if you are not on the latest Win10 version.

I've never seen this problem being specific to a version of Windows, but generally related to the quality of power supply in the computer

Are the DAC and computer plugged into the same AC outlet?

 

[Berwhale]

I had a similar issue and fixed it with a cheap isolator...

Nobsound USB to USB Isolator Module Audio Noise: Amazon.co.uk: Electronics

I bought a more expensive isolator at the same time, which didn't fix the issue, so it went back...

iFi iDefender+ External USB Audio Ground Loop: Amazon.co.uk: Electronics

You might want to order the Nobsound and see if it works for you (and send the Intona back if it does)

 

[Bcquinn]

I've never seen this problem being specific to a version of Windows, but generally related to the quality of power supply in the computer

Are the DAC and computer plugged into the same AC outlet?

They are, but I also tried plugging them into separate outlets (e.g., on different walls)—no improvement.

 

[Bcquinn]

I had a similar issue and fixed it with a cheap isolator...

Nobsound USB to USB Isolator Module Audio Noise: Amazon.co.uk: Electronics

I bought a more expensive isolator at the same time, which didn't fix the issue, so it went back...

iFi iDefender+ External USB Audio Ground Loop: Amazon.co.uk: Electronics

You might want to order the Nobsound and see if it works for you (and send the Intona back if it does)

Thanks so much for the tip—will see if I can give that a shot.

 

[Dunring]

I just got done chasing down a USB noise when volume was over 75% which was coming from the USB hub plugged into the back. I solved it by putting a big EMI filter (like the size that come with a TV to fit over coax) right over the USB plug in the back of the system, and a little electrical tape since it didn't close completely. That shielded the USB plug enough that the noise floor vanished. I put another smaller one on the cable anyway. Amazon has an assortment of sizes in a pack, I ordered some from China but those took six weeks to arrive and only saved like 3 dollars. The really big ones are great for shielding a USB connector plug if there's room around it to fit (I just relocated some near it to the hub on the monitor).

 

[Harmonie]

I just got done chasing down a USB noise when volume was over 75% which was coming from the USB hub plugged into the back. I solved it by putting a big EMI filter (like the size that come with a TV to fit over coax) right over the USB plug in the back of the system, and a little electrical tape since it didn't close completely. That shielded the USB plug enough that the noise floor vanished. I put another smaller one on the cable anyway. Amazon has an assortment of sizes in a pack, I ordered some from China but those took six weeks to arrive and only saved like 3 dollars. The really big ones are great for shielding a USB connector plug if there's room around it to fit (I just relocated some near it to the hub on the monitor).

While masking the noise is certainly a good solution, I wonder if you couldn't avoid the noise or hum at its source?

 

[AnalogSteph]

If clipping on a ferrite clamp solves the issue, it's 100% to do with common-mode RF traveling down the cable, likely involving frequencies well in the MHz at least (there is no shortage of sources for high-frequency content inside a PC, including USB itself, and RF is taking strange paths at times). One would have to know the rest of the system for a decent guess of where the problematic demodulation may have occurred. The crux of having super high bandwidth inputs is that input filtering may actually prove insufficient under some circumstances.