I need help on how to keep my Musical Fidelity X-PRE tube Pre-Amp from picking up Radio Frequencies. I live in a condo building and a few blocks away I can see a radio tower antenna which I assume is causing this problem. When I put my ear close to any of my speakers, I can hear faint signals. Only a DVD player and an ADCOM 535L Amp are connected to the pre-amp using PureSonic double shielded inter-connects.