I've been up all night trying to track down the phono preamp buzz, and I think I've found a workable solution. I moved the tonearm and motor ground wires from the external preamp to one of the screws holding the lid on the 950. Seems close enough to a chassis ground to work. I have DSS satillite TV, not cable. I've heard many horror stories about ground loops from the cable when connected to home systems, even when using so-called ground solutions.