A single coil pickup, which I have shown on the other pages, is where there is a single coil of wire around a single pole (under each string). This magnetic system also, in addition to producing an electric current, acts as a very efficient antenna. This coil of wire takes radiation out of the air. Radiation is always around us all the time, be it from the 60 cycle AC current in the building wiring, or the noise from fluorescent lights. The single coil pickup will therefor pickup this noise and produce a nasty little hum along with the vibration of the string.

In 1955 a Gibson engineer, Seth Lover, invented the Humbucker pickup. The pickup actually cancels out the hum picked up by single coils. The humbucker has 2 coils and has an additional magnet or set of magnets, or even magnetically charged poles, on opposite ends of a single magnet. The two coils are wound with opposite electrical polarity and the magnetic polarity is also reversed. Each of these coils carries two electric signals, the intentional vibration signal, and the unintentional noise thats picked up. The polarity of the wanted signal is dependent on both the polarity of the magnet and the direction of the winding, whereas the unwanted noise is independent of the magnets and depends only on the direction of the winding. Therefore, the noise signal is cancelled, eliminating the hum.

Most humbuckers are wider than single coils, although there are stacked humbuckers available which look similar to single coil pickups, only taller.

Most fender guitars that come with 3 pickups, actually use the middle pickup as an effective humbucker. The polarity of this middle pickup is opposite that of the neck and bridge pickups.

The most recent development in pickups are the new optical pickups. They actually use a laser that is directed onto the string. When the string moves, the laser can detect the amount of movement and translate it to a current. This completely eliminates all unwanted noise that even magnets have.