Jim Rolph, of J.M. Rolph Pickups in Highland Heights, Kentucky, specializes in building and rewinding pickups. Jim introduced us to the benefits of a magnet polarity tester.
"This is the most frequently used tool in my shop, and it's something that repairmen, dealers, collectors, players—anyone who deals with pickups—needs."
"Once a pickup leaves the original owner's hands, and it's not marked, how else are you going to know the magnet polarity? How many times have you wired a pickup and found that it's magnetically out of phase, even though the white and black leads looked right? You end up with the same thin, low-powered, tinny sound as a pickup that's wired out of phase. The tester eliminates that problem. I don't see how a shop working on electric guitars could operate without a tool like this. There's no money in doing a job the second time!"
"When you're at a show looking to buy a guitar, knowing the polarity of the pickups can mean the difference between buying an untouched piece or one which looks right, but has had a pickup or two replaced. For your records, here are the usual magnet polarities on some of the most common vintage pickups":
- Tele bridge pickups remained south-up from the start, and the neck pickups were north-up. Later, probably in the mid 50s, the neck became south-up.
- Strats were always north-up until 1960 when they became south-up, and have remained so except for some of their newer products such as their ‘Texas Specials.'
- The Jazzmaster came along in ‘57 with a north and a south to make them hum-cancelling in the middle position (as did the Jaguar, Mustang, and Jazz Bass-paralleling Gibson's new humbucking pickup, which debuted with the Les Paul that same year).
- The P-Bass has one part of the pickup north and one part south, also making it hum-cancelling. Early P-Basses with the Tele-style headstock had a Strat-shaped single coil pickup.
- Gibson P-90s are always south-up, and their P.A.F. humbuckers were south-up on the screw side, and north-up on the slug side (hidden under the covers). The later patent number humbuckers remained the same.