Did you have the hum like you do now when you used the cart. in a different system? If not, it's doubtful it's the cartridge.
I know you've tried lot's of different phono cables, but where any of them shielded? If your not using a shielded cable it can cause a lot of hum as your describing.
I know you've tried lot's of different phono cables, but where any of them shielded? If your not using a shielded cable it can cause a lot of hum as your describing.