Turntable hum ground issue?


Help? Just switched amps from a Mcintosh MA-6500 to a MA-7000 and I am getting a pretty bad hum from my VPI Prime. I have swapped cables. same issue, when i lightly touch the tonearm wire (between tonearm and rear connectors) the hum increases BUT when I touch the ground connector on the back of the VPI the hum reduces considerably. Any ideas? The hum even reduces if I touch the top of the amp. Sounds like a ground issue but not sure what to do to trouble shoot. Also it was happening with my other amp but not as bad. Also touching the cartridge does not affect it one way or the otherĀ 



marsrecords
Marsh you need ground wire from your turntable to your phono preamp or preamp.
Tried bringing the amp to another circuit and though it may have reduced it a little it is still thereĀ 
Sounds like something in the arm wiring is messed up. Grounding the ground wire is the clue- it increases hum. Sounds like the arm tube isn't grounded properly.