I got rid of all the noise apart from the very low level zipper noise which is audible at high gain when moving graphics windows? I'm still not sure that is an USB IRQ problem.
Does IRQ sharing create that in Windows 7? It's impossible to get all soundcards on an isolated IRQ.
Ok after getting it all setup comfortably I then plugged in my AXIOM 25 Midi keyboard and that high pitch whine entered the stream. It's running off USB power mind you. No mains adapter. Is the internal USB power generating the interference?