I recently installed a new set of Dimarzio Ultra Jazz Pickups. I followed the installation instructions thoroughly. The only problem is a slight hum. I don't know if I am properly grounded. When I removed the old pickups I removed the copper wire strip to the bridge and the plates beneath the old pickups and the grounding wires. I have a grounding wire from my first pot to a plate in the control cavity, That's it. When I add treble either on the tone knob to on my amp the hum gets worse. Also when my hands on the strings the hum stops. I know the new pickups are humbucking so I assumed the old grounding was not necessary. Any Ideas?