[denti]

I've been getting an awful static-y, crackling, with occasion high pitched sounds (you know, computer noise) over USB audio and I cannot locate the source of the problem.
 
The noise is hard to describe, but it's not hum. It's closer to EMF interference.
 
Here's the set-up and what I've ruled out:
 
Using a Bottlehead headphone amp, being fed from Gustard x20, which is fed from a self-built PC.
 
I've ruled out the amp, the DAC, and the wiring (including USB cable). Using my laptop instead of the self-built PC into this chain I don't get the noise.
 
So it's the PC. I'm running Windows 10, using JRiver 20, and outputting DSD. The processor is an Intel i7. 8GB memory. I've been using a Gigabyte H81 motherboard.
 
But here's the deal, I've further ruled out: the power supply (which I switched out yesterday, and it made no difference), as well as the USB wifi stick (I loaded a track on the hard drive and played it from there instead of from my server over my wifi). And today I tried a new motherboard! Same problem!
 
At this point I'm looking at: memory, processor, or hard drive. But, really, would any of these three be the source of the problem? I'm started to feel like I'll never get to the bottom of this.
 
I should note that I don't even need to play music to hear this noise. It's present as soon as I turn on the computer, and it seems to intensify with PC activity (start-up, start-up of program, playing music, etc.) I'm starting to suspect it's the memory.
 
Any help would be greatly appreciated!!

 

[NA Blur]

To me crackling is almost always a problem with the DAC or a driver. You can try uninstalling the USB driver for your DAC and then reinstall it. Hopefully that helps. Many times trying to output DSD only causes problems. I would look into the sample rates and see if lowering it fixes your problem.
 
Also try:
 
Another USB port
 
Removing wi-fi from the area including your phone
 
Turning on Power Management for the USB port you want to use

 

[pinnahertz]

Try one of these on the DAC and amp:
https://www.amazon.com/CableWholesale-Wholesale-Grounding-Converter-30W1-32200/dp/B000I96AUM/ref=sr_1_3?s=electronics&ie=UTF8&qid=1492418320&sr=1-3&keywords=ground+lift
 
AND when you do that, using a separate wire from each, ground the chassis to the PC, at a point where the PC power supply ground is connected.  Some place on the PC case might work.  
 
Also try that adapter on the PC with the other devices plugged in without it, same ground wire scheme. 
 
 
You could also try one of these:
https://www.amazon.com/HifimeDIY-Isolator-ADUM4160-signal-isolation/dp/B00F4SCCR2
 
It won't support DSD or anything above 96kHz, but may help you with diagnosing the problem.
 
You can forget memory, processor, hard drive.  They won't change a thing.  
 
Coulda told you a mother board swap wouldn't help, and a power supply swap won't help either, unless you radically change the type and design of the power supply, which still may not fix things.  
 
I also suggest you google "USB ground loop" and read up.  It's a very common problem. 

 

[denti]

I tried one of these:
https://www.amazon.com/gp/product/B018H0JK28/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
 
and it made no difference.
 
I don't understand how MB, memory, power, or HD can't be the issue. If they aren't then what is? Like I said, this doesn't happen with two other computers I tried! And the noise is there before I even play anything. 

 

[pinnahertz]

It's coming from the power supply and is related to a ground loop. Try the other options I posted. And google USB ground loop and PC ground loop.

Memory and HDD can't be the issue because they never are. Yes it is a power supply issue, but you can probably get around it by adjusting how the other components and the PC are grounded.

 

[denti]

The whole point of going with the components I have was to get DSD256 and higher. So using a USB isolator that limits me to 24/96 defeats the purpose. Are there any that would do?
 
What are my options? Someone on this forum recommended this setup for me to get DSD to my Gustard, and now it's noisy. Do I need a different kind of power supply? Which one?

 

[denti]

Furthermore, I touched the USB directly to the RCA inputs of the amp, which I shorted and disconnected from the DAC. No noise. That suggests it's not a USB leakage loop.

 

[pinnahertz]

  The whole point of going with the components I have was to get DSD256 and higher. So using a USB isolator that limits me to 24/96 defeats the purpose. Are there any that would do?
The isolator should be considered a diagnostic tool. It's clearly not a final fix.

What are my options? Someone on this forum recommended this setup for me to get DSD to my Gustard, and now it's noisy. Do I need a different kind of power supply? Which one?

Is there something wrong with the options I've been posting?

 

[pinnahertz]

  Furthermore, I touched the USB directly to the RCA inputs of the amp, which I shorted and disconnected from the DAC. No noise. That suggests it's not a USB leakage loop.

 
Not, that's not what that shows at all.  Your problem is a classic PC ground loop.  Your challenge is to either eliminate it (that's what all those different grounding experiments I've posted are all about), or find a way to isolate your gear from the issue.  
 
If you come up with the specifications for your power supply there are low-noise units available that could solve your problem.  However, that's always necessary.  Solve the ground loop, you solve the problem. 
 
Any chance you've had time to google your problem?

 

[denti]

I will try getting the 3-prong to 2-prong plugs and attaching a wire as suggested. Am I right in understanding this wire goes from where the 3rd prong was to the chassis?

 

[denti]

Googling "PC ground loop isolation" opens a vast world that I'm not sure I know how to navigate. Hence my posting here. But I will keep looking. 

 

[pinnahertz]

  I will try getting the 3-prong to 2-prong plugs and attaching a wire as suggested. Am I right in understanding this wire goes from where the 3rd prong was to the chassis?

Not necessarily as that's hard to get to.  Any place on a metal chassis is usually ok.  Clipping a wire to the outer contact of an RCA jack is also great for a chassis and signal ground point.  The idea is to connect your amp chassis to the PC chassis, but not ground it via the power cord.  AND do the same with the DAC.  See what happens.  Then you could try the power cord ground for the amp and DAC, but the use the adapter plug on the PC keeping your ground wires in place.  It's a bit of an experiment, very cut-and-try, but rarely is this unsolvable. 

 

[denti]

OK, will try. 3-prong to 2-prong on PC power supply, with a ground wire running to the amp chassis or ground. Easy enough.
 
How do explain that I get no noise using my laptop?

 

[pinnahertz]

  OK, will try. 3-prong to 2-prong on PC power supply, with a ground wire running to the amp chassis or ground. Easy enough.
 
How do explain that I get no noise using my laptop?

It's the laptop power supply.  Happens to be either cleaner (less noise), or use a better grounding scheme, or both.  Some laptop power supplies are horrible.  I have an HP that is really bad.  I would say generally that cheaper power supplies are more problematic, but that's not 100% true.  Sometimes within a brand things work out better.  For example, my Apple products for the most part are devoid of power supply noise issues.  

 

[denti]

Remember that I switched out the power supply on the PC and had the same problem.
Anyway, I now have the plugs, so I'll experiment later tonight.
Thanks!