What cleeds said, plus have you tried disconnecting the ground wire between components? And obviously check the cartridge grounds. Both channels?
New Sugar Cube is picking up hum from phono stage
Phono stage is the source of the hum. It is in my new system and the phono stage is a PS Audio Stellar. The ground wire is secure between the TT and phono stage and there is no hum if the Sugar Cube is powered off. It is a low level 60 cycle hum. The new Sugar Cube is model SC-1 Plus. I have tried moving the two units apart, up one shelf, but that made little difference compared to stacking them. I would like to add a shield between the two components and stack them. Has anyone had a similar experience, or can offer advice or reference guidance?