Imac, h2 and hms and router are all plugged into the same high quality strip from olson electronics. there is no way around this right now. Surely being an optical connection it is fully galvanically isolated and it is an impossibility that any RF could enter the hms through an optical connection? thanks Nick. i understand a battery powered source is vital for a usb connection not optical which is pulses of light a medium in which RF cannot exist.