Pickup pole measurements

[Hneel]

Recently I bought an SH-4 JB pickup for my guitar. But now I noticed that the poles of the magnets don't allign to the strings. (See picture). I knew that some pickups were branded for bridge or neck position, but I always thought that had to do with windings, magnets, sound, etc. Now I googled and learned that the distance of the poles play a role too. It should be 49 mm for the neck and 52.5 for the bridge pickups, if I understand correctly These are more or less the string distances on those positions on my guitar. Which is a Squier Bullet Mustang HH. On my other guitar, a Les Paul clone, the distances are the same. And on both guitars the original bridge pickups had pole distances of 52.5 mm.
Then why does the SH-4 JB have a pole distance of 49 mm? Is it really a neck pickup instead? Or did I somehow end up with a wrong pickup?
I'm confused.

 

[GuitarStv]

It's not a matter of bridge and neck. 49mm is traditional Gibson spacing for both bridge and neck pickups - Gibson used slightly narrower spacing at the bridge than Fender. This won't quite line up on guitars with a fender style trem (or Floyd Rose). 'Trembucker' / 'F-spaced' bridge pickups were designed to be a little bit wider (usually about 52 mm) for this reason.

Your Les Paul clone and Mustang both sound like they've got fender spacing rather than traditional Gibson spacing.

If you play with a lot of gain you might not hear the difference between having the pole pieces lining up exactly - many people don't care at all about this. I play mostly clean, can hear a volume drop off and it bugs me, so I always make sure to measure and order the right spaced pickup for the bridge.

 

[Mr. 80's]

Your bridge pickup is also off center to the right so it looks a little more dramatic than it really is. You can probably shift it to be more center in the hole.

 

[beaubrummels]

Then why does the SH-4 JB have a pole distance of 49 mm? Is it really a neck pickup instead? Or did I somehow end up with a wrong pickup?
I'm confused.

SH model pickups are standard humbucker spacing.
TB model pickups are Trembucker(tm) spacing (Fender spacing)

Original 1950s - 1970s Les Pauls have standard humbucker spacing.
Recent era Les Pauls have a wider spacing at the bridge where either standard or Fender spacing would work. (I don't remember which year they introduced the wider spacing)

If you are installing on a Fender-type instrument or recent era Les Pauls, a TB model bridge might be advisable, though either pickup should work on a Les Paul. Having a standard spacing pickup under Fender spacing strings will work, but in some cases, with certain combinations of strings, string gauge, string material, guitar bodies, bridge type (Floyd vs Strat vs hard tail vs string-through-body, etc.) may have slight issues on the outside E strings, e.g. they might be weaker. (I had this happen on my Jackson and I just raised the outside poles and it evened out.)

 

[Mincer]

Either spacing of JB would work sound-wise, as it is a powerful pickup that 'hears' the strings even if the poles are off. The Trembucker-spaced JB would look better but pretty much sound the same.

 

[Wound_Up]

It's not a matter of bridge and neck. 49mm is traditional Gibson spacing for both bridge and neck pickups - Gibson used slightly narrower spacing at the bridge than Fender. This won't quite line up on guitars with a fender style trem (or Floyd Rose). 'Trembucker' / 'F-spaced' bridge pickups were designed to be a little bit wider (usually about 52 mm) for this reason.

Your Les Paul clone and Mustang both sound like they've got fender spacing rather than traditional Gibson spacing.

If you play with a lot of gain you might not hear the difference between having the pole pieces lining up exactly - many people don't care at all about this. I play mostly clean, can hear a volume drop off and it bugs me, so I always make sure to measure and order the right spaced pickup for the bridge.

I seriously doubt you can hear a difference from a pickup that's moved over 0.020"

Its not like the magnetic field ends directly at the edge of the pickup pole/screw. So these tiny distances won't even make a difference. The strings are still in the magnetic field so there's no way you could hear a difference. There's no difference to be heard when the string never leaves the magnetic field above the pickups.

 

[GuitarDoc]

I think the biggest problem is that your bridge pup is mounted way off center.

 

[GuitarStv]

I seriously doubt you can hear a difference from a pickup that's moved over 0.020"

Its not like the magnetic field ends directly at the edge of the pickup pole/screw. So these tiny distances won't even make a difference.

Not really a tone difference, but for me I was getting a very easy to hear volume drop on the high E string (which was the pole furthest from the string on the guitar that I experienced it) playing clean. With gain it didn't seem to make any difference. I could jack up the screw on that side but by the time it was high enough to help, the tone actually did change for that string a bit. Now granted, the strings were a little bit off-center over the pickup to begin with so the problem was probably exacerbated a bit - but it went away completely switching to an F-spaced pickup.

The strings are still in the magnetic field so there's no way you could hear a difference. There's no difference to be heard when the string never leaves the magnetic field above the pickups.

The strings are still in the magnetic field when a pickup is 1 mm from the string, or when it's 8mm from the string. The tone and attack will be very different though - even though the strings never leave the magnetic field above the pickups. Where in the magnetic field the string is matters and is certainly audible.