The paticular pc I am using gives me feed back on all 3 usb hubs. It is a very low feedback thats only noticable when the music isnt playing. Im thinking a ground issue in the pc or a flaw. Does anyone know of some kind of usb filter that isnt obnoxiously ugly that will eliminate the low humming wine. Does it at my studio and the club. Just irritating that I walk in with 8 grand of equiptment and when I hook it up someone always states I here feedback. It also has feedback when the 57 is off but hooked to the laptop. Thanks

do you get the hum when the pc is using battery?

Havent checked... Good point.

Holy crap it is the power supply. Good call. Whats the fix besides running battery performance?

www.amazon.com

Thanks... On it

Bought it at gc. Took the problem out. Works perfect. +1

yeah worked great for me good to hear it got rid of your problem

What you had is what's called a 'ground loop'. Laptop power supplies are notorious for causing hum, this hum is then sent down the earth part of from the laptop power supply cable and picked back up again by the earth of the mixer, hence the loop. You can go out and buy a $90 isolator, or take the ghetto route and get a short pice of extension cable and cut the earth (green) cable and plug you laptop cable into your new modified cable. This is exactly what most hum 'isoloarors' do anyway. Yes it is perfectly safe, afterall the laptop is still eartthed through the USB, all you're doing is stopping the earth cable from acting like an antenna.