USB bus noise?

[a1rocketpilot]

I am in the process of peer-reviewing Asr's GLite LE. When I hooked it up to my HagUSB and turned up the volume, I heard some static and some strange beeping noises. I later found out that the beeping happens whenever I move my mouse (which is USB). Is this noise caused by dirty power that the HagUSB is drawing?

To throw another wrench in the mix, the noise was present on the GLite, however, on my HA-2 MKII SE, which has a gain of 7 as opposed to the GLite's 6, I hear no noise at all, except maybe a slight increase of the noise floor at max volume, but no beeping or anything. Anyone have any idea what's going on here??

Aditya

 

[Publius]

Do you have any audio cables wired from that device to another sound card?

 

[Andrew_WOT]

Infamous ground loop.
Just lift the ground on GLite or HagUSB or both, that should do. You need cheater plugs for that, available at RadioShack.

 

[a1rocketpilot]

How would I go about doing that? And given that it is only an issue with the Gilmore, wouldn't that mean that the fault lies with that device instead of with the HagUSB? Could it have anything to do with the differing input impedances?

Aditya