Since the pickup is the meat and potatoes of an electric guitar or bass, let’s have a think about how they actually work.
How Does a Pickup Work?
At its absolute simplest, a guitar pickup consists of a magnet with a bundle of wire coiled around it. The magnet produces a magnetic field around itself and the wire coil.
The magic bit is this: If you wiggle certain metallic objects (like a guitar string, for example) in this magnetic field, a small electrical current gets generated in the wire coil.
That’s it. Really. You can think of a pickup as being, essentially, a tiny electrical generator* and, when you strum a chord, you are providing the vibrating-string energy which is converted into electrical energy, sent to your amp and made bigger (technical term).
Of course, things can always be made a little more complicated and our magnet and coil can be modified to achieve different tonal aims. First, though, let’s expand a little on our very basic pickup principal.
A Fender-style single-coil pickup is a good place to start examining these things. Like most things that Leo Fender had a hand in, it’s designed to do a good job with the minimum of fuss.
In this pickup we have six individual magnets, one for each string. Here, the magnets are narrow cylinders with one end being the north pole and the other being the south. We usually refer to these magnets as poles, pole-pieces or slugs.
The six magnets are held in place by a fibre or plastic plate at the top and bottom. The same pole (north, for instance) must face up for each magnet in the pickup.
A thin wire is wrapped directly around the row of magnets and, after about eight thousand wraps or so, you have your pickup coil.
Because the coil wire is incredibly delicate, the beginning and end—or in pickup lingo, the start and finish—of the coil are connected to heavier hook-up wires to be wired into the guitar.
For the curious, the finish wire of the coil usually becomes the hot wire which carries the signal. The start is generally the ground wire, mainly because those first wraps contact directly with the pole pieces. Of course, since all of the start/finish thing is effectively ‘internal’ to the pickup, you don’t really need to worry about it.)
The single-coil pickup: Simple, straightforward and they sound great.
*SUPER GEEKY NOTE: Strictly speaking, a pickup is a ’transducer’ which actually converts one sort of energy (vibrating string) to another (electrical). Of course, strictly speaking, a generator is actually a transducer too but that’s probably an argument for someone else
COMPLETE GUITAR WIRING
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