The early VPI speed controllers were not well shielded and commonly would cause hum if placed too close to phono preamps or the table itself. The SDS is OK. If you have a speed controller that is a pre-SDS VPI product, try to move it far away from the table and, importantly, far away from the phono preamp. Good Luck.
hum with VPI Jr
I have returned to analogue recently and bought a VPI Jr with a AQ 7 arm and Benz Glider M2(purchased used here on Audiogon about 6 months ago). I am getting a low pitched hum when I place the cartridge on the record. This hum is not present with the table on unless the the cartridge is actually in contact with the record. The ground wire is connected although I have not checked it for continuity. The table is plugged into to a speed controller. Any advice on eliminating the hum ?