Guitar wiring

Pickups convert the mechanical energy of a vibrating string to an electrical signal, allowing it to be amplified, processed and reproduced.

[1] Pickups vary greatly in construction, size, types of materials used, as well as various electrical properties, but are generally divided into two categories – single-coil and double-coil (also known as humbucker).

The Varitone is actually a variable notch filter consisting of one of several capacitors (selected with a rotary switch) in series with an inductor, forming an LC circuit.

Some manufacturers have used a pot to vary the amount of signal shorted to ground from one coil, thus producing a range of tones between a humbucker and a single-coil.

This modification requires the start and end of both coils to be exposed, which is more commonly available on aftermarket than stock pickups.

In case of a humbucker this results in a sound that is so weak as to be almost unusable, as well as the loss of the pickup's hum-cancelling properties (due to the coils being magnetically out-of-phase, but electrically in-phase with each other).

Compared to coil split the sound is usually a bit fuller and the pickup's hum-cancelling properties are retained.

The operation is the same as in a balance control found in stereo equipment – in the middle position (often marked with a detent) both pickups supply their full output, and turning the pot in either direction gradually attenuates one of the pickups while leaving the other at full output.

While the modifications described above have all been passive (i.e. they don't require an external power source), active electronics considerably increase the number of possible wiring options.

These can range from simple preamps that offer a volume boost and buffer the instrument's signal (to prevent loss of higher frequencies in longer cable runs), to multi-band equalisers and more.

[30][31] Enterprising guitarists have even built entire effects processors into guitars, such as the Korg Kaoss Pad.

A diagram showing the wiring of a Gibson Les Paul electric guitar. Shown are the humbucker pickups with individual tone and volume controls ( T and V , respectively), 3-way pickup selector switch, tone capacitors that form a passive low-pass filter, the output jack and connections between those components. The top right shows a modification that allows both pickups to have their volumes adjusted independently when the selector switch is in the middle position: the two bottom connections are simply swapped on each volume potentiometer.
Underside of a 1981 Fender Lead I pickguard, showing the wiring.
A diagram showing a wiring modification for a Les Paul or a similar electric guitar with two humbuckers. Wiring schemes using four push-pull pots for additional pickup combinations were made popular by Led Zeppelin guitarist Jimmy Page and later produced as a signature model by Gibson . The modification shown in this diagram is an evolution of the original concept combining coil splitting, phase cancellation and parallel/series switching for a total of 22 different pickup combinations.