pickup construction

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pickup construction

Postby pbman1953 » Wed Jun 23, 2010 6:58 pm

I have a pair of jazz bass pickups that the magnet is on the bottom . Why would it have a magnet on the bottom when there are already the pole peices?

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Location: Boston

Re: pickup construction

Postby Rodent » Tue Apr 29, 2014 2:31 pm

Zombie thread alert!!!

There are multiple ways to get the pole pieces magnetically charged.

One design method is to use pole pieces made from magnetic material like some formula of AlNiCo (2, 3, and 5 are the most common we see in pickup building) Cut open an old P-bass or J-bass coil and you'll find it's thin copper wire wrapped around magnets that are held in position by some type of material that is stable with heat and humidity changes. The magnets in this design are charged sometime during the pickup build process, typically near the end, and can slowly lose their charge over time - but they can be recharged quite easily at any time.

Another method is to use ferrous metal slugs for pole pieces, and then place a bar shaped magnet (most commonly a much cheaper ceramic magnet) across their bottom side to effectively build the magnetic field that the string interrupt to make your signal. If you take apart an early G&L MFD pickup this is exactly what you'll find - thin wire wrapped around ferrous metal slugs (that are drilled/tapped internally so a screw can be adjusted up/down to fine tune the magnetic field) with a bar magnet across their bottom side. The magnets in this design are charged before leaving the place where they are made, so it removes a step in the pickup building process.

Each design style has its advantages and drawbacks, and each has a subtly distinct sound.


The pickup noted by the OP is most likely the latter design style. I have seen this type of J pickup on many of the cheap import Fender basses, and swapping the pickup set out for a more vintage design yields a more familiar tone.

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Re: pickup construction

Postby Rob Francis » Tue Apr 29, 2014 5:42 pm

Thanks Rod!
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