I'm afraid it means that you have a ground loop, which often occurs when connecting audio units to PCs. It will probably be helped if you plug your computer and your audio rig into the same power socket.
Other wise you could try a USB isolator. These are available from Amazon for about $40, but we have not yet tested them (we will shortly).
Yeah i figured it out later that day. The problem is that most usb isolators give 200ma at best and the mod factor needs 500ma.
I can always upgrade and replace it with an H9 core 🙂 bluetooth isnt noisy
The mf is not powered from the usb – it maybe needs a few mA. Anything that isolates the ground and provides a tiny bit of power should be OK.