I shielded my jazz pickups as in: covering coil with electric tape, then covering that w/ copper, making sure no copper touched the coil or the output signal, and of course grounding the copper to the ground output. I did a very neat and clean job... I figured all I would loose is a little high end...right. Now, I have a HUGE loss in output, and when I engage the S1 switch (Ameri J Bass) I get a VERY LOUD hum ? anyone?