Good advice from @erik_squires about shielding also you want to keep the phono preamp near the TT and the cable between the two as short as possible. Are you sure all connections are tight, especially at the cartridge pins.
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.