Guitar pickup pole pieceUnited States Patent 4624172 from 1956..
A pickup assembly for stringed instruments such as guitars or the like, consists of a hollow cylindrical tube of magnetizable material in contact with a permanent magnet to produce an electro-magnetic field, one upon each side of one free end of the cylinder and a resistive field coil in operative connection with the cylinder in a conventional manner. The vibrating string of the instrument passes diametrically over the open end of the pole piece cylinder spaced slightly above the surface there of and between the two magnetic fields which are situated one upon each side of the longitudinal axis of the string. This permits free vibration of the string at all frequencies without any dampening or attenuation occurring. End…
Let’s be realistic here. . . MOST pickups are manufactured in the same way. They use a pole piece generally a magnet of an alnico alloy. These pole pieces are inserted in a bobbin to ensure exact center to center spacing of the pole pieces and proper alignment with the strings. Around this bobbin is wrapped a tiny copper wire approximately the thickness of a human hair. Usually from 40 to 44 gauge wire is used. The wire is coated with varnish to prevent it from grounding itself out during the winding process. The thinner the wire gauge used the greater the number of turns around the bobbin that can be effected. . . resulting typically in a higher output, but yielding a muddier sound. If thicker wire is used less windings are possible but the pickup will have a brighter sound. Also the distance between pickups and the exact position of the pole relative to the string length also effects tone (You know. . . if you strum near the neck you get one sort of sound. . . and picking in close proximity to the bridge yields a brighter, more brittle sound, right?).
This is an oversimplification, but I suspect you’re getting the point, that is, that wire gauge, magnet alloy, number of windings, shape of the polepiece, pick up aperture and focal point . . . all of these things must work together to create a great sounding pickup.
See our article on 22 fret or 24 fret guitars, perhaps it will make more sense. Enjoy