I had a hum on my TT as well. Had to crank the volume up a bit, but it was there. Turns out it was my TT lite. I unplugged it from the Richard Grey 1200s (the lite) right under the phone stage to the shunyata hydra on the floor and hum is down 90%. Only apparent when I crank volumn up to 90 (out of 100). Will play a bit more but I may just live with it until I upgrade...something.
Grounding Hum
I recently got a new TT for Christmas. It's an MMF 2.2 LE. I think there's a grounding problem or something because there is a slight buzzing noise present. I looked through past threads on the topic here, but nothing seems to fit this situation. I've checked, and rechecked the connection between the TT, and the preamp. I've even used a Fluke voltmeter to check for continuity between the two. I've checked the headshell leads to the cartridge. All is well. Maybe it's the ground wire connection to the turntable itself? I've run out of options. Any ideas?