I have a 74 Fender Jazz with the Sadowsky preamp and I had my repair guy swap out a set of fender scns for a set of dimarzio ultrajazz pickups. Now there is a buzzing noise that wasn't there before. My repair guy is not a real electronic specialist so I want to ask here before I go back to him. The dimarzios are humbucking pickups with two coils next to each other. So it's one coil for the E and A strings and the other for the D and G strings. What happens is that when I touch the pole pieces on the E and A string part of the Bridge pickup it buzzes and on the neck pickup the D and G part buzzes but the opposite coils don't. Again, Both pickups have only one coil that buzzes when I touch the pole pieces and the other remains quiet. The sound of the bass is completely normal, full and round not out of phase sounding. What could be the cause for this?