Since changing my DAW to a faster PC running windows 7, I am being plagued by constant low-level background noise which I can hear on the fire-wire interface outputs. It seems to be related to HS6 and sounds like "frying". It's not the interface because I've swapped the Behringer out for my old M-Audio Firewire 410 and the noise is still there. The noise can be heard to change whilst moving the mouse around and oddly, disappears when highlighting a track box to type in the track name. When a track is playing it becomes inaudible below the track audio of course.
 
I'm also using the same cables as previously, but changed them over just make sure, but it's still there.
 
Anyone had a similar problem or recommend how to cure it. It's not that it's bad, but it wasn't there before the PC upgrade and is damned annoying!! 

I hear 'mouse noise' even on my XP 32-bit machine. Don't know what it is and never worried about it, since it's not real loud and doesn't seem to be rendered on audio export...
Just wanted you to know you're not alone.

Thanks for that Greg, appreciate the input. My Firewire FCA1616 also has a USB i/f capability, so I might give that a try and see if it's any different.
 
Mike

Sounds electrical. Firewire tracks power to the device. Perhaps there is not sufficient isolation?