MY RECORD PLAYER IS BUZZING A LITTLE BIT

It's coming from the turntable itself rather than the speakers. It happens whether or not the sound cables are plugged into the preamp, and whether or not the preamp is switched on. The only thing that makes it go away is unplugging the turnable?

Any ideas? I can't find anything on it that looks like it's where an earth cable should go.

Also, the amp itself has been vibrating ever so slightly when you touch it, like there's a teeny bit of static coming out. Do I need to do anything about that?