Fender P-Bass Pickup - Different magnetisation between E+A and D+G sections?

[nilebodgers]

Just got a new P-bass pickup (Fender Original Vintage #0992046000 - alnico 5, "vintage 62" design) and in the process of messing around with it I offered up an allan key to the pole pieces to see how heavily magnetised they were.

It looks to me like the 4 poles in the D+G section of the pickup are more heavily magnetised compared to the 4 poles in the E+A section. (the level of magnetisation appears the same within each section though)

Has anyone else seen this? I've never seen this mentioned before, but it looks like a way of balancing the different string output.

I fitted the pickup today and it works perfectly and is nicely balanced across the strings, so that difference appears intentional.

 

[Killed_by_Death]

Just a guess, but I think what you're experiencing is opposing poles.
One side has the North poles facing up & the other has the South poles facing up.

If the output is balanced across all strings, you're golden.

 

[nilebodgers]

That's a thought - I didn't check that the allan key wasn't already partly magnetised. That would explain an apparent difference in magnet strength if the polarities are flipped between the 2 halves.

I'd need a gauss meter to test properly and I don't have one.

Sounds good and is balanced across the strings though, so it's just my curiosity itching

 

[96tbird]

Mags are magnetized as the last step of the build process before passing along to be installed. They are usually swiped, by hand, by humans, through a magnetic field a couple of times. It is unlikely that each pole is exactly equally magnetized due to many variables. It is just as likely that it doesn’t matter. Why would you get a gauss meter when you can just use your ears?

 

[nilebodgers]

Because I'm an engineer. I want to measure and know the reason behind things, not just a subjective result that can't easily be reproduced.

 

[Killed_by_Death]

The North/South hypothesis is easily testable, just get another magnet & see if it's attracted to the pickup poles in the same way.
If it opposes on one side & attracts on the other, then you know the poles are reversed between the pickups.

Normally a humbucking set of coils are set up Reverse Wound Reverse Polarity.
Well, they actually NEED to be set up this way in order to cancel hum.

 

[96tbird]

Because I'm an engineer. I want to measure and know the reason behind things, not just a subjective result that can't easily be reproduced.

Ahh special needs. Thankfully TB is is fully inclusive.

 

[Keen Amateur]

"It looks to me like the 4 poles in the D+G section of the pickup are more heavily magnetised compared to the 4 poles in the E+A section."
At an older Japanese P-Bass the same found.
Also engineer.