Thanks for the input. If I understand this correctly, I don't think I am having ground fault problems, because when the cartridge is swung away from the table (past it's rest), the hum essentially disappears. Thanks all for the cartridge suggestions. I was actually considering the Grado Sonata Statment, but was concerned about the hum on the Platinum Reference. So you are saying the low number of windings on the Statment cartridges reduces hum from the motor? Even with greater need for preamplification? I think the statements are 0.5 mV.