Pole piece adjustment on a jazz bass

[walterw]

If the pickup is built with taller poles in the middle, you're not only moving the magnetic field up closer to the higher-up strings, you're also adding a larger/stronger magnetic field and a larger chunk of permeable and conductive material right under those strings. You're going to get more difference output than the height change difference would suggest and also an ever so slightly warmer tone on those two strings.

that's what fralin does, the middle magnets are a little taller so the slightly closer distance plus the slightly bigger magnets combine to get the job done

this also avoids the issue of too-tall J magnets digging into the fingers when you play over them

 

[PawleeP]

that's what fralin does, the middle magnets are a little taller so the slightly closer distance plus the slightly bigger magnets combine to get the job done

this also avoids the issue of too-tall J magnets digging into the fingers when you play over them

i may send my 2 destroyed fender pups to lindy for a 9.5 radius rebuild with the slightly taller 4 middle magnets, when i can afford it. ya'llz have been a big help.

 

[Yahboy]

Thanx ww, Do you know if anyone has successfully adjusted the inner poles on an sjb1. I have already tried it on a few fender jazz pups and ruined them. rekon maybe i should have read more threads first and or tried heating them pup a little with a hair dryer. Not sure if that would have loosened the apparent vulcanizing.

Check my post....

2016 USA fender jazz pickup pole pieces

I did lot pickups pole piece raise on single coil jazz pup/Tele pup and both ceramic and alnico stingray pickup for even string to string output.

But, I not suggest raise the magnet pole on split coil/humcancelling jazz pup. Because those A and D pole piece are easy moveable on single coil which those winding coil just pass around them instead wind around on split jazz EA and DG pole piece individually.

 

[Jefenator]

I tapped up the inner poles on a single coil P-bass pickup once and got away with it. I wouldn't try it on anything rare & expensive (which creates kind of a catch-22 - the tinkering helped some but I ultimately never bonded with that particular bass).
For my J-bass, I just got a set of Lollar pickups (which sound fantastic and have raised inner poles) and called it a day.

 

[PhatBottomBass1]

Just a point regarding radius of poles/magnets in the design of pickups.

Mike Tobias always has Bartolini build his pickups with a curved top of the pickup casing to accommodate the curved blade/bar magnet inside. This is the same idea as raising the A/D string poles on a standard single coil or HC J Bass pickup.

I am putting a DiMarzio Model J in the neck with the adjustable poles and an Ultra Jazz with the raised poles in the bridge of my Fender 74 AVRI with a 7.25" fingerboard radius. Why?

Because it does make a difference!

 

[Nebadon2000]

This is Pickup for D/G on my Ultra P[p/j] split coil [G are raised ones] all others including J are flat.
I don't remember poles being raised when new[12/19]; then I noticed G string being louder and saw poles raised over cover. I can only get G a tad under 4/64ths away from string with last fret fretted pickup all the way down.

I adjusted by ear all other pickup heights to match [G] by ear to my preference; have no 'to close to string' sound problems in fact it sound great; fender recommends 8/64 on Bass and 6/64 on treble and same for Jazz

My final measurements came in 6/64 Bass and 4/64 treble with slight differences for A/D on split coil and 8/64 and 6/64 on J pickup [P pickup seems to have lower output than J when soloed] I got good string balance in P,J and Blend modes.

After I noticed raised poles [few months after purchase] I put piece of foam on far end of treble pickup under cover so now poles are flat with cover like the rest so not to hit actual poles when playing over pickup. But now I am still concerned about resale; it is under warranty but I will need to take it to local GC and you can't by P Ultra pickup as replacement part and there is some concern about it being available for warranty work at this time. Was hoping I could push them down but that ain't happening

 

[mickebas]

The Di Marzio J's are a good solution to this problem... if that's your sound. I like them and use them on some of my J-style 4 stringed instruments. But if you have this balance problem om a vintage rarity that apart form the dynamic unbalance has a perfect sound it's harder. I was lucky, even though probably stupid enough, to physically alter the hight of the poles without damaging them. Nowadays I would not try to do that but depending on the total originality status of your instrument I think I would custom order pickups with different pole piece hight and keep the originals.
Also this is an issue that tends to diminish nowadays since it's mostly the vintage instruments (or new with vintage specs) that uses the more rounded radius. Many players seems to prefer the flatter fingerboard and then it probably isn't that big an issue anymore. But for us vintage nerds that still wants a balanced sound it is.

 

[iiipopes]

Ooops!
Well, everything turned out good this time and the bass is now playable
I can’t help wondering after + 40 years as a J-bass player, why the pole pieces does not follow the radius. I’ve never encountered a jazz bass that doesn’t have a too loud E- string and a weak D-string. This must be well known by now and still I have the same problem every time.

This is exactly why traditional bass string sets have a tight D string and a loose E string: the D string is tighter, meaning more mass, so it produces more output for that string, and likewise for the E string, less mass for slightly less output, with the added bonus that a lesser diameter core string tends to vibrate more freely, which means more overtones, which means more consistency of tone string-to-string and less thump out of the E string.

 

[mickebas]

This is exactly why traditional bass string sets have a tight D string and a loose E string: the D string is tighter, meaning more mass, so it produces more output for that string, and likewise for the E string, less mass for slightly less output, with the added bonus that a lesser diameter core string tends to vibrate more freely, which means more overtones, which means more consistency of tone string-to-string and less thump out of the E string.

Well, according to the logic in my experience it doesn’t work then. Simply because my problem usually is just that of too loud outer (E&G) strings. And Ive been using very normal gauges through the years. Using a heavier D- string (70-75) helps this issue but it’s a bit to heavy a set for playing comfort.
On a P-bass this is not an issue naturally.

 

[iiipopes]

Well, according to the logic in my experience it doesn’t work then. Simply because my problem usually is just that of too loud outer (E&G) strings. And Ive been using very normal gauges through the years. Using a heavier D- string (70-75) helps this issue but it’s a bit to heavy a set for playing comfort.
On a P-bass this is not an issue naturally.

And it is not an issue on many newer basses, especially 5-string basses, which have a 12-15 inch radius instead of the vintage 7 1/2 inch radius, so there is not as much variance of the height of the strings above a flat pickup, like a vintage J-bass or soapbar. I use the D'A XL170BT 45-60-80-107 plus a 130 B string tuned to C and have good even response across the board, fret board, that is, pun intended.

 

[mickebas]

And it is not an issue on many newer basses, especially 5-string basses, which have a 12-15 inch radius instead of the vintage 7 1/2 inch radius, so there is not as much variance of the height of the strings above a flat pickup, like a vintage J-bass or soapbar. I use the D'A XL170BT 45-60-80-107 plus a 130 B string tuned to C and have good even response across the board, fret board, that is, pun intended.

Right! It’s mostly a traditional jazz bass problem and maybe it’s only a problem once you notice it and start to realize the dynamic issue.
I used to have a compressor even out the sound but it’s still not a solution with different compression amount on different strings. Custom ordered pickups or as some companies now have, the option of raised A-D poles, is the way to go if you have a vintage specified Jazz bass.