I have a new system built with a Gigabyte Gaming 7 Z170X motherboard, using the on-board graphics (no additional video card). I have tried 2 USB audio interfaces (Focusrite and Steinberg), and both put out this computer noise that happens when the computer seems to be transferring data around. It doesn’t matter what USB port I try. See this video for the sound, turn up volume, it’s faint.
Any ideas?
If you are using speakers that accept balanced lines use balanced cables and that will probably end the problem. It worked for my setup with a UR44.
Using balance cables stopped the intermittent computer buzzing? I wouldn’t have thought that would be related. Did you hear it in the video?
I am currently having to use RCA cables to connect to my Home AVR until I can get a studio setup properly. It doesn’t have balanced inputs.
Why oh why couldn’t they have included a digital out on the UR44??
Because they want you to buy the next model up from the UR44. 
(I didn’t have to listen to your video because I understand the problem.)
I wonder. Confirmation would be nice.
Thanks.
There are other threads about it, but they deal with headphones if I remember correctly. It also depends on the device and how the USB connections are implemented, and it might have to do with how your PC is grounded, and how the outlets you devices are plugged into are grounded.
In addition to data transfer noise, things happening on USB, like mouse movement, and noise from the graphic card, built-in or otherwise can be heard depending on the setup. It’s difficult to troubleshoot.
This sound is like data moving through a bus, or hard disk activity, etc. I am sitting here in the quiet, except for the occasional faint screech of computer noise coming through my speakers. I have only heard this before when using the audio out built into a laptop, never on a desktop computer. I might have to try another motherboard, but that would suck.
The computer is normally grounded, UR 44 is not via the factory power supply, and the audio AVR is normally grounded. The Focusrite that did the same was USB powered.
This doesn’t seem like a grounding issue due to the intermittent nature, but I suppose there might be something that would make a difference. Can’t imagine what.
Even assuming it’s not a grounding problem, the function of a balanced connection is to eliminate noise. A good read is the wikipedia article Balanced audio - Wikipedia
Try disabling the cpu power saving features in the bios…C-States, Speedstep, EIST.
That is an amazing suggestion- I would never thought of it. But it’s quite possible! Problem with high pitch noises - ThinkWiki
Sadly you give me too much credit for thinking of it…I can only take credit for vaguly remembering reading something about it and google did the rest 
But it isn’t a fix in all cases from the sound of things and possibly lahatte already made these bios settings as they are included in a few optimisation articles…though opinion is divided on whether necessary with the latest processors.
Hi.
Thanks for the link to the noise troubleshooting. I will look through that.
And yes, balanced cable might indeed help, as was stated, it’s purpose is to reject interference.
I have recently plugged a PC3x keyboard into the UR44 inputs. When I increase the input gain that noise gets much loader, which is very odd since it is coming from the computer via USB. But I immediately thought about balanced cable, and I suspect if I could used balanced cables for that connection it might not have that noise on that, and fortunately the PC3x has balanced outputs. Unfortunately, I don’t have any balanced cable available at the moment to try due to a remodel mess (doh!).
Can you lift (disconnect) the ground on your computer and stereo? If this is a ground loop that might work by breaking it, with the disadvantage of having no ground. The Kurzweil has a grounded plug, yes? What you said about the noise when you plugged it in sort of makes that sound possible, via both audio and USB connections
That suggestion could make your gear unsafe, of course so don’t do it! 
Another, safer, way would be a couple isolation transformer circuits placed between the UR44 outputs and the stereo like: http://a.co/5KS8Gcf
DIY: Oops! My mistake this page has been moved. [error 404]
SOS article discussing this:
For those coming to this thread- I just want to add that the best way to deal with this is to be able to have balanced connections between the audio device and the speakers. Of course this is only possible if you gear has balanced connectors.
Direct boxes perform a similar function, and I would suppose some headphone amps incorporate isolation circuits too, for people who are using laptops on batteries.
Thanks Steve. I did think about lifting the grounds, but I haven’t been able to test that yet. I’ll need to get some more ground lift adapters. Maybe just for the test I’ll just rig up something temporary to see if it makes a difference. I will report back when I do that.
Did you try/had you already done my bios tweaks suggestion?
I have not had the chance to try anything yet. I will try the ground lift first, I think, just to see if that makes a difference.
Ok, so I lifted the ground on the computer only. The noise is basically gone.
My PC3x is still connected to the UR44 with unbalanced cables, and when I un-mute it in my DAW I get the noise via that. I tried lifting the PC3x ground also which made no difference.
Steve, I am sorry to have doubted you. 
I will try the computer tweaks, where applicable, when I can.
Thanks.
Grounding is so weird.
Thanks.
Right on, man. No worries.