I just installed the Seymour Duncan Musicman replacement system (pickup and preamp) - Alnico p/up - in my Stingray. It was pretty easy to install. I love the sound. However, I've noticed that when I touch the pickup pole pieces with my finger (while not touching anything else) I hear a buzz. Any idea how to fix this? Is this common with Alnico pickups? Any help would be much appreciated. Thanks!!!!