A multi-meter is a handy tool for guitar players to have on their work bench. They have a myriad of uses when it comes to guitar, effects and amplifiers, and it’s always worthwhile having even a basic multi-meter around to troubleshoot things.
In this article I want to talk about the physics behind pickups in order to explain why using the DC resistance as a measure of output is not the best way of viewing the output of a pickup. But first, what is DC in the first place? Why is it relevant at all when it comes to pickups? When those questions are answered we have to take a look at the origin of the signal itself: where does the signal come from? Why are magnets and coils so crucial?