The original humbucking pickups designed by Seth Lover in the 1950s were elegantly simple. By combining two pickup coils instead of simply using one (with pole piece magnets of one coil oriented in the opposite direction to the other), Lover’s design cancelled out the buzz and hum that plagued existing single coil designs, leaving in its place a fuller, rounder tone which changed the future of guitar.
For many years, the humbucker sound suited players just fine. You were either a humbucker player or a single coil player, and if you wanted to switch from a humbucker sound on one song to a single coil sound on another you needed to pick up another guitar. And this is where the four-conductor cable humbucker comes in. By including ‘start’ and ‘finish’ wires for each individual pickup coil of a humbucker, these coils can be combined or separated by a switch or pot.
There are many reasons to do this: to access single coil sounds by sending the output of one coil to ground (effectively turning it off); or to connect the pickups in parallel instead of series (similar to having two single coils very close together); some players even have one of the two coils wired to a potentiometer so that they can blend as much or as little of it with the other as they like. There are plenty of wiring diagrams for different options here.
Many Seymour Duncan humbuckers (such as the APH-1 and TBAPH-1 Alnico II Pro) feature four-conductor cable as standard, but many others can be ordered with this feature even if their spec sheet calls for two-conductor cable. Examples include the SH-55 Seth Lover and the SH-1 and TB59 ’59 model, each of which offer vintage-inspired tones. Pair these pickups with elaborate switching, as Joe Gore does in the ‘Pagey Project’ video below using a set of ’59s, and you can access a range of series, parallel, single coil and out-of-phase tones.
If you’re ordering a new pickup, it’s worth it if a four-conductor version can be made, even if you have no current plans to implement these mods; you never know what you’ll feel like doing in the future!