Turntable hum

What preamp or phono amp are you using? Does the hum change as you mov the tone arm across the record?

Thanks so much everyone for your thoughts!  I will check these out tomorrow when I’m at work as I brought this turntable in to work to replace a Thorens 135 that stopped working.  It is going through the phono input of an Ampex integrated amp into powered Genelec speakers. 

Oh and the hum does not change in relation to the tone arm. 

Sounds like an electrical issue as @almarg  suggested.

Btw, polarized plugs are not a “nanny state” encumbrance. They ensure that equipment which has a “grounding resistor” from neutral to chassis, usually several megohms, doesn’t inadvertently have the chassis become energized to hot lead potential by mistake. The whole concept is flawed of course.  ULc, CSA and UL allows this terrible method of false economy for a manufacturer to avoid cost of a proper grounded power cord.