Oh yeah. I'm not questioning the USB input of the amp. I'm questioning the USB output of the computer. I know the PC is the issue. I'm trying to find a way to salvage the use of the PC in a cost-effective manner. I only mentioned the totally silent analog signal from a lowly Kindle via a lowly patch cord to contrast it with the relatively noisy sound coming through the USB which is supposed to be better. These two ways of transmitting a wired signal to an integrated amp are giving me results that are opposite of my expectations for them given the hype about digital and DACs and USB transmission, et al.

I am still confident that the DAC in the amp is better than the DAC in my 7-year old low end Dell computer sound card. Analog from my Kindle or from the headphone output of the computer may be quieter (silent), but the audio coming through the USB is likely cleaner, if only I can tame/eliminate the low level of background hum/garble.

Looks like that might work. To be clear,at this point we're really just guessing that noise is coupling through the power lines of the USB though that seems to be the most likely candidate. It makes sense to not spend too much money trying this and that...

Although I think it lies with the PC somewhere we haven't ruled out the 2150 as the problem since the noise is present with both your desktop and laptop as the source. Is there any other component between the source and the 2150? The usb connection on the 2150 could be bad and creating the noise. Have you contacted Outlaw for troubleshooting yet.

No, I haven't asked Outlaw to do any troubleshooting yet. I like to do as much troubleshooting as possible myself, first. I haven't yet crawled under my desk to reconfigure what is plugged into what device. I have a UPS that I might try plugging the computer and amp into directly. There are 5000 combinations of what is plugged into what that could potentially resolve issues like this one.

Have you directly connected the computer to the 2150 with no intervening components.

The only intervening component is a powered hub. The port in the powered hub produces less noise than the USB port on the back of the computer.

Try going direct without the hub. It could be the hub has a conflict of some sort with the PC connected.

The powered hub is quieter than going direct into the back of the computer. I've tried that. I'd guess the hub is 30% quieter. And the hub, with power, is quieter than the hub with the power unplugged.

Has anyone tried the Wyrd "Decrapifier?"
http://www.amazon.com/dp/B00LFVMC9U/ref=...=I1Q9C10RNUR2XG
If that device doesn't work, I can always return it. This is my next to last resort to try before addressing the problem with Outlaw.

I assume my USB input on the Outlaw amp should be dead quiet (using fairly sensitive headphones), even with the volume up at 50% or more.

I was suggesting a new sound card to obtain analog L/R inputs to the 2150 vs. using the USB cable. This would completely remove the USB, and any noise associated with it, from your setup. I haven't done any research as to which would be a good choice, though. I know there are some that provide RCA connections right on the card and others that use the little headphone jack style.

Through all the troubleshooting the 2150 seems to be the common component assuming a different USB cable has been tried out. I would call Outlaw before spending any more $$$ on external components.