I have an old B & O belt drive turntable that I love, but it builds up a hum as it plays. I've tried connecting a simple ground wire to the amp body, but it does no good. the only thing that work is to touch my finger to the aluminum deck of the body of the turntable, but it doesn't last. Any ideas?
It sounds as if a ground has got interrupted. You need a multimeter.
Check continuity from the two ground pins on the cartridge to the shields on the RCA plugs if it has them or the center ground pin if if is DIN.
Check that the arm body is grounded.
Check that the turntable ground is connected to the turntable grounding wire.
Make sure what ever the turntable is connected to has a good ground.
The fact that you touching the turntable alters things, is pretty much proof that all items are not grounded as designed.
Turntables are pretty simple so you should be able to sort this out.
