Interface suddenly buzzing, please help...

[Heathathon]

I have been using this new Alesis iO2 Express interface for a couple days without problem. Today, however, when I plug the damn thing in, I get a horrible buzzing sound. It happens through both mic ports and both guitar ports. When I unplug the AC adapter from my laptop, it reduces it by about 80%. However, I have been using it with the AC adapter the past few days, and I have not had a problem. Plus, the extra 20% is still there now, and I have no idea what is causing it... What's more, if I unplug the AC adapter, the interface loses power and shuts off. I have checked my power settings and have everything USB related disabled... I'd appreciate any advice I can get... Thanks.

 

[PRHunt]

Could be a ground loop, in which case a galvanic isolator for the usb port might help.

Otherwise, try moving equipment around, keep the AC adapter away from the audio equipment, turning off other electronics devices, powering from one power outlet.

Paul

 

[mjbphotos]

Unplug (not just disable) any other USB devices. If the laptop can't power the Alesis via USB when unplugged, it might be a laptop problem.