Something in your system is acting as an antenna. It usually is connected to ground. Now you have to go by trial and error. Disconnect all the ground wires and put ground cheaters on the phono stage and preamp power cables. See what you have for hum. Now remove the cheater from the phono stages and connect the tonearm ground wires to the phono stages. If there is no hum or noise stop here. If you are interested in finding the criminal add one wire or remove one cheater at a time. When the noise returns you have found it.
Phono cartridge noises
Hi All,
I finally after many years built a new home with a dedicated music room and was quite happy with it until I connected my turntables. I've never run across this and looking for advice as I'm truly lost on what I’m experiencing.
I have two phono preamps, the Jolida JD-9 II / Grado Gold G2+2 High Output cartridge / Project RM 1.3 and a Black Ice Fusion F159 / Grado Reference Low Output cartridge / VPI Scout. Without the cartridges connected I have a slight bit of air noise when I turn up the volume which I kind of expect. As soon as I plug in the cartridges I pick up what I think is internet noise and not in a small way. The high output masks it to a point, the low output can't be used at all. It sounds like I'm on a spaceship! It's a high pitched noise with a morse code like beeping sound, a lot of background kinda rumble/flutter and distortion. The room is wired for ethernet but as yet not connected I only have WiFi in use. When I switch to any other source input on the main preamp all noise goes to silence. I have connected the phonos with different cables from Transparent Audio, Morrow, Original phono cables that came with the tables and even tried an old set of Monster Cables; all produce the same result as soon as the cartridge is introduced into the loop.
Has anyone come across this I'm truly stumped?
K