Hum Problem with Grado

Same problem for me with my VPI M4 and high output Grado Sonata. Not a huge hum, but motor induced and noticable at high volume levels. I shielded the motor assembly with two layers of mu metal and the hum is pretty much completely gone, I'd say 90% reduced. I could only hear the hum on the last three inches towards the spindle when not actually playing. But you know it's there. Easy to do and effective. A very good tweak for me because the cartridge wasn't cheap. Good listening.

http://www.lessemf.com/mag-shld.html

This might help: https://www.haglabs.com/collections/accessories/products/humbucker

Another way to eliminate the hum is simply to see to it that the motor has a wire between it an the tonearm ground. 

I tried that too, connecting ground wire to motor (bearing too).  Didn't do a damn thing... 

In this case, the problem is magnetic, and you have to deal with it very differently.

Nice rule of thumb:  If you hear "buzz", it is electric field coupling, add a ground wire.  If "hum", then magnetic field coupling, add distance. 

I have NO hum with Grado XTZ on all my turntables (i have 7 of them).
You’re better search what atmasphere posted in another thread, the problem is your turntable.