Use shielded cables with the shield attached to the ground pin and not the signal end.
May help to use a Furman strip with LiFT and SMP. They have really great EMI/RFI as well as audible frequency filtering.
Remove Radio Station Background Noise
What is the best way to remove radio station sound from the TT feed to the pre amp?
When I turn the volume up to about 50% I can hear radio station noise if my ear is next to the speaker.
I started using clamp-on ferrite chokes that clip around the cables from the TT to the phono preamp to eliminate the noise. I wanted to know if there is a better solution or if the ferrite chokes compromise the sound.
The TT is a VPI Classic 3. The phono preamp is a Sutherland PhonoBlock and the pre amp (DMC-30SV) and amps (DMA-400) are Spectral Audio. All cables are MIT Oracle MA-X.