Re: What causes a pickup to go microphonic?
Gripweed, there are others far more technical than I, but if I understand correctly, the individual wires in the PUP are being vibrated, much like the body of a guitar vibrates with feedback.
There are 2 ways to stop it that I know of..pot the pickups (usually emersing them in wax) or try a different PUP-
If you go for potting, read up because it can change the soudn and you can melt the whole thing if you aren't careful-
Hope this helps