Noisy USB port on desktop computer

There is some noise coming from my desktop computer's USB port - more from the port directly on the back of the computer than through the self-powered USB hub, but still a nuisance on quiet passages.

I have confirmed that more noise is coming from the desktop computer than from the USB cable by trying a laptop. This resulted in about a 50% decrease in noise, but it was still there, which means that either most computers generate some noise, or the cable is partially to blame.

What solutions have you experienced to eliminate noise on the USB port? If I can't reasonably quiet the USB line from my computer, I will need to consider other sources to play my music files from.

Related: Has anyone wired their tablet, especially the Kindle Fire HDX into the USB in on the RR2150? I'm not sure if a usable USB digital signal comes out of the latest Kindle Fire HDX or not. What has been your experience with tablets as a source compared to a desktop computer as a source?

Still no solutions to the USB noise problem. I will try this: http://www.amazon.com/dp/B00LFVMC9U/ref=...=I1Q9C10RNUR2XG
If that doesn't cure the problem, I will address this through Outlaw.
I didn't expect to have to spend an extra $100 to cure a problem in a USB input that was supposed to improve the sound. Hmmm.

I am not sure buying another component is going to solve your issue. You mention a self powered USB hub. What else do you have plugged into the hub? USB has current limitations and if I had to take a guess you have most likely found and exceeded the upper limit for your system. System quality is also a factor when it comes to noisy USB

I have an Intel board in my multimedia machine and found the onboard USB to be lacking. I would look at adding a proper USB card before anything else. Much cheaper with an opportunity to upgrade to USB 3 if you are not already there.

I unplugged all other cords from the hub with no difference in result. Even though only around $20, a new USB card is "another new component." There is nothing in the literature of a number of new USB cards that claims they minimize or suppress or deal with noise any better than any other USB. How can I know that this would work any better than the card I am using? Is there something about newer USB cards that make them less prone to generate or transmit noise? What distinguishes "a proper" card from the one I have? How is that kind of card identified?

Call Outlaw

Hello Clarinet. The idea behind unplugging everything except the USB cable in between the computer and the RR2150 is to eliminate as many items from the chain as possible. I have an old Kodak photo printer that will create a hum through the onboard USB every time it is powered on.

Any modern day USB 3.0 card requiring a connector from the power supply with be capable of running signals at a higher speed and carrying more current than the USB hub on the motherboard in your system. Even on multimedia boards the USB header will not be up to the same standards as a card built for the purpose. The audio chain can be a fragile thing so lets not connect it to the same power supply and signal path used by the printer and other peripherals when at all possible.

It is how I fixed a similar issue in my system. I was told by my geek to treat it like a ground loop hum

Am I allowed to name the card I used on the public forum?

XenonMan makes a great suggestion as well. I have spoken with Ben on several occasions and have found him to be knowledgeable and genuinely interested in helping.

I agree with Stephen B in that until you eliminate all the possible sources of the noise you can't fix the issue. Going directly from the laptop or PC via a good USB cable will allow you to decide if it is the computer, the cable or the 2150 usb port.

Great idea to "unplug everything." But I've already done that. I've both unplugged all USB cables from the hub, as well as run the USB cable directly from the back of the computer with nothing else plugged into it. The USB noise was worse directly from the computer, even without anything else plugged into USB ports. The powered USB hub clears it up "some." The noise I get is not so much a "hum" but a low/mid frequency static sound on top of a slight hum.

Also, on my wireless trackball mouse, when I rotate the track ball I get an additional layer of mid-pitch static. When I move the scroll wheel and there is something to scroll on the screen, I get an added layer of low pitch hum. If I turn the scroll wheel and there is nothing to scroll, there is no additional noise. Fascinating, eh Scottie?

This is in addition to the noise constantly there.

Fascinating indeed. We can run this down we just have to work by the numbers and it will get sorted.

Have you tried a different cable than the one you took from the desktop to your notebook? If you are right on the coast connectoritis is quite common and can occur both inside and outside the system unit. Check all of the connections carefully looking for any crud or corrosion.

Who made the trackball and how does it connect to your system unit? You said wireless so I am guessing it connects via USB? Have you tried unplugging the trackball while playing music? If the trackball can add noise does unplugging it while listening to music reduce the noise? Do you carry the trackball between your desktop and notebook? If the only thing moving between your desktop and notebook was the USB cable then lets please set that one aside while we troubleshoot the issue.

Here are a few general questions but we might as well try to cover everything.

I forgot to ask earlier, PC or Mac? If running Windows which version?

How is your desktop unit connected to the wall outlet? any surge suppression or battery back-up? (any major electrical storms or power outages lately) What else is plugged in through the same outlet? How do you connect to the internet?

What is connected to the computer and how does it connect? Are you using all factory cables or have you switched any of them for some reason?

Has anyone worked on the computer requiring the case to be opened? If so what service was performed?

I know it is a bunch of questions but we should be able to narrow it down quickly.

I used the same cable to compare the notebook and the desktop.


Logitech connected to a USB via a dongle. No difference in noise level with and without the dongle plugged in.


Yes. And I unplugged that and all other USBs and noise did not change.


Yes. No change, with and without playing music.


No, no change.



No.


PC, Windows 7


PC connected through the "surge only" side of a large APC UPS along with the Outlaw amp. Previously I powered the amp from a smaller surge suppressor to see if there was any change in the mechanical noise in the amp from the toroidal transformer. No change in either the transformer buzz or the USB noise between the two.


Nothing else.


DSL via Century Link Prism router.


A Davis Instruments weather station is plugged into the computer as well as the APC USB, and a TV used as a monitor. There was no change when I unplugged all USBs.

Only me. I replaced an optical drive and added an AMD Radeon HD 7700 Series video card.



I have ordered the Schiit Wyrd Decrapifier. If that solves the problem without spending more hours of troubleshooting it will be well worthwhile. If not, I'll return it. I should get it by Jan 7 and have more info mid-week.

Question: Should the USB "in" be totally quiet even with the volume control on the RR2150 cranked up 25% or beyond without music playing? 25%+/- volume setting is when I begin hearing the USB noise.

I would think so. I do not have any integrated units with USB so only have the OPPO to go by but it is dead quiet between tracks when fed via USB. Have you tried playing something from a thumb drive?

It only makes the noise when using the USB input?

Does it make the noise when the usb is selected as the source with nothing plugged into the USB input? You may have to crank the volume a little to hear it but it should be silent.

With the USB cable removed from the amp, the signal is dead quiet with the volume cranked all the way with USB source selected.

Yes, this noise is evident only when using the USB source with the USB cable plugged in.

Try it again with the usb plugged into the amp but not plugged in to a source. Just trying to eliminate the amp as an issue. Try several usb cables if you can.

Does the transformer noise you discussed on the other thread still exist? Why are you using the surge only side of the APC?

Looking at the manual for the RR2150 the amp should not be plugged into any switching outlet such as those found on your APC UPS (all of the outlets on my APC are of the switching type). If you could, try running an extension cord from another room for the Outlaw and see what if anything that might do for the transformer noise. Surge suppression should protect equipment from external sources but does not necessarily protect from other gear on the same surge suppressor. Plugging the RR2150 into its own outlet away from the APC unit would be a good start. With everything plugged into the same surge suppressor a ground loop or feedback noise from the computers power supply is quite possible. The outlet on the APC marked specifically for the system unit is filtered to prevent power supply noise from effecting the other equipment. In the days of CRT monitors it would show itself as static on the monitor.

Do you have one of these by any chance? Checking outlets for open grounds and polarity issues might give us some clues.

http://www.amazon.com/gp/product/B005GYB...BR13TGS6KDGYRHY

Keep the faith and we will figure this out.

The noise goes away entirely when I disconnect the cable from the USB hub but leave it connected to the Outlaw's USB in.

http://www.amazon.com/APC-Retail-Battery...asin=B002QR7DHS

I am using the "surge only" side of the UPS because I don't want the amp to suck capacity out of the batteries for the computer if I get a power failure. I have the amp plugged into the non-switched (not controlled by master), non-backup portion of the UPC (lower right in the photo). The computer is plugged into the backup side of the unit (left side). I don't have anything plugged into the "Master" outlet (top left in the photo.) Nothing is being switched from the UPS.

Yes, I do have one of these. The outlets tested "CORRECT":

I'll get back after trying a different outlet.

Knowing the outlet is good is a great start. The spec sheet for your UPS shows the max power output at 780 watts.

You might just be on the edge of the max output rating for the unit. My APC unit does have facility to shut off the power to the surge only side making every outlet a switched outlet. Yours may be different.

The transformer hum on the Outlaw is evident when the amp is idling, no signal, drawing little power. The USB noise, the same. So it is unlikely that the UPS is creating any of this because of its 780 watt capacity limitation. The idle draw of the amp is 5 watts; full load is 400 watts. The power supply on my computer draws <150 watts. Nothing else is plugged into the UPS.

Is the hum from the transformer or is it a ground loop hum from the speakers? Does the transformer hum with the speakers not connected?

It is a mechanical noise from the transformer. The transformer hums with the speaker selector "on" or "off." I did not try it to see if there is a difference with the speakers disconnected.

USB Noise Update:

I received and connected the Schiit Wyrd decrapifier. The verdict...

It's a keeper. Prior to connecting, the USB noise was first noticed with the volume control set at 25% on up. Now the volume has to be cranked beyond 65% to first notice the noise. Listening through headphones I will rarely have the volume approach 50% and most often around 25% with the headphone level control set at 50%. So for all practical purposes, my problem is solved. Not being proficient at estimating db, but I'll gander a guess that I gained about 10db to 15db of USB distortion-free volume (S/N ratio.)

My suggestion to anyone with annoying USB noise, after you try a few different computer USB ports and a couple of different cables and the noise is still there, try the decrapifier though Amazon. You can return it if it doesn't work for you. But there's a really good chance it will.

Have you had a chance to listen to any high resolution files? I would be interested in hearing your thoughts to compare with what others have had to say.

Ground loops are tough to kill and switching power supplies in desktop computers can be the worst offenders of the bunch.

What characteristics should I listen for? My initial impression if pressed for an opinion is that the sound is a bit cleaner and more detailed. But I am not a trained supercritical audioholic type of listener (except for my noise aversion) so I might be missing something. Any differences are likly very minor and only discernable in an a/b test which is hard to do switching cables.

I can't imagine that eliminating several decibels of underlying noise wouldn't clean up the whole package a bit.