I've heard of the ERS cloth. You could probably start experimenting with various shields, lead sheet or even tin foil slid under the subplatter FWIW and see what happens....
also try turning the cartridge clips a little bit to adjust your contact, there may be a ground issue too. There's a lot of other things you can try including chnaging receptacles to a different circuit (start with an extension cord). TT different from the other gear.
also try turning the cartridge clips a little bit to adjust your contact, there may be a ground issue too. There's a lot of other things you can try including chnaging receptacles to a different circuit (start with an extension cord). TT different from the other gear.