Help with USB jitter
Apr 21, 2013 at 5:46 PM Thread Starter Post #1 of 12

Rawdawg3234

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Hey everyone,
I recently moved my wadia to my hi fi setup and now need a source for my desktop. Right now i'm running a usb straight to my da100 and I'm getting a lot of interference,i.e. low level buzzing and noises from scrolling on the computer.

My Question is:
Will upgrading my usb cable stop this? maybe something shielded? Or do I need to buy a converter and just run spdif or coax to my DAC?

Thanks
 
Apr 21, 2013 at 6:01 PM Post #2 of 12

K_19

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What you are hearing is not what jitter is (which no one can explain for sure what it exactly sounds like), and I don't think replacing the usb cable will solve that problem as I'd think most USB cables out there would be sold with adequate shielding. It's probably the interference the DAC or amp is picking up (though I don't ever get interference with my own DA100 through USB. Probably depends on a lot of setup factors).
 
With DA100 a good USB-SPDIF converter is recommended anyways. Although the USB on it is passable it's nothing special (I believe it does plain old 16/44 at max) and quite outdated... thus even something as low as my original M2tech Hiface makes a noticeable difference on my DA100.  Not sure if that will solve your interference problems but I encourage you to look for a converter anyway.
 
Apr 21, 2013 at 6:15 PM Post #3 of 12

Rawdawg3234

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Thanks I was planning on getting a v link anyways but I needed a temporary solution.
I just ran my printer USB to the stello which is 12 ft long.
Correct me if I'm wrong but I thought for longer data cables like that you need way more shielding from interference and I also believe a braid is neccesary as well.
 
Apr 21, 2013 at 6:27 PM Post #5 of 12

Rawdawg3234

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Will do thanks.
Never had an issue with my wadia hooked up the exact same way though
 
Apr 22, 2013 at 5:49 AM Post #7 of 12

Rawdawg3234

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Can't see how it's a looping issue. All my components are running through my power conditioner so I have only one ground. Maybe a loose ground wire?
Also I'm positive it's the USB causing the interference cause its there no matter what output I select on my DAC but as soon as I unplug the USB it stops.
 
Apr 22, 2013 at 3:15 PM Post #8 of 12

grokit

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Quote:
Can't see how it's a looping issue. All my components are running through my power conditioner so I have only one ground. Maybe a loose ground wire?
Also I'm positive it's the USB causing the interference cause its there no matter what output I select on my DAC but as soon as I unplug the USB it stops.

 
Thais could be the problem, the common ground. Again try the suggestions above.
 
Apr 22, 2013 at 3:31 PM Post #9 of 12

Rawdawg3234

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Thanks for your help. Same problem though once I changed outlets and even put plugs on different outlets.
I thought a ground loop was caused by more than one grounded plug being used?
 
Apr 24, 2013 at 3:00 AM Post #11 of 12

mich41

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Computer motherboard's "ground" is actually few millivolts above the real ground because there is a current flowing from motherboard "ground" traces to the real ground through cables which have some nonzero resistance.

Apparently your DAC isn't designed to deal with being connected to two "grounds" which aren't actually the same. You need a USB isolator to disconnect it from the PC ground; there are few threads on USB isolators on HF if you don't know where to look for one.
 
May 30, 2013 at 12:02 PM Post #12 of 12

Rawdawg3234

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Quote:
Computer motherboard's "ground" is actually few millivolts above the real ground because there is a current flowing from motherboard "ground" traces to the real ground through cables which have some nonzero resistance.

Apparently your DAC isn't designed to deal with being connected to two "grounds" which aren't actually the same. You need a USB isolator to disconnect it from the PC ground; there are few threads on USB isolators on HF if you don't know where to look for one.

Thanks for the advise. The usb isolator did the trick. 
 

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