String spacing and effect on pups picking up

Gearhead

I don't seem to be able to find any info on this, so maybe the resident tech heads can clarify:
I would like to know what the tolerance is one has if the string spacing does not match the pickup. Example: on a 56mm spaced Strat there's a 50mm humbucker pickup (not the low-gauss type). Would this be able to properly pick up tone from the outer strings? What is the limit?

AlanRatcliffe

As a problem string spacing is greatly overrated. IMO the biggest problem is cosmetic rather than sonic.

Firstly, the diameter of the pickup spacing is from centre to centre and the polepiece has a larger diameter itself (usually about 4mm with a humbucking pickup), so each outside polepiece extends 2mm beyond the centre of the polepiece, adding a total of 4mm to the string spacing of the pickup. So in your example of a 50mm pickup, the total pole spacing is actually 54mm - which leaves only 1mm on either side - and that's with the very wide vintage string spacing of 56mm - the modern 1-1/8" (54mm) and 1-1/16" (52.4mm) string spacings are even closer.

Secondly, the pickup is slightly forward of the bridge, so the strings are slightly closer together than the at the saddles, where the spacing is measured.

Finally, the magnetic field of most polepieces extends beyond the diameter of the polepiece (exception given to some designed specifically with narrow magnetic fields such as Lace Sensors).

So all-in-all, you're covered. The only time it becomes a problem is when the bridge pickup is both Gibson-spaced and misaligned.

Gearhead

Yeah, along the lines I supposed; thanks a lot for the confirmation.
The problem is with a certain Casio guitar (http://www.guitarforum.co.za/your-gear/my-casio-has-some-street-cred/) that at some point had a Gibson spaced neck humbucker installed in the bridge position. It also has had an upgrade of the tremolo which makes it 56mm spaced over 47mm pole piece spread. We'll have to see what we can do here; I was proposing something along the lines of a DiMarzio Virtual Vintage '54 Pro Noiseless Single-coil now that this one comes with black cover ? but the owner of the guitar should decide.

AlanRatcliffe

The big question would be: is it affecting the volume of the outer strings?

Gearhead

It does, but it seems to affect the highs more? Sending PM...