Slugs not touching the bar magnet

[foonting]

Just had a new batch of baseplates and made a couple of humbuckers up for clients ... I was slightly disturbed to see daylight on assembly between the slugs and the magnet with the coils butted up together. Not much daylight but certainly a bit ... but has anyone else encountered this and does it make a profound difference?

[SkinnyWire]

This is not at all uncommon with the readily available parts, and I've seen gaps in vintage pickups too. There are tolerances to all parts ... sometimes the magnet is ground slightly on the plus side of tolerance, sometimes on the negative. Keeper bars may vary slightly in width, in the way the holes are drilled (dead center, offset, etc.). Never really experimented to see if the tonal difference between a tight fit and some "air" gaps is "profound". Obviously, all else held equal the field strength at the poles (ergo the strings) will be less than if the magnet was in direct contact with the slugs, but profound? Probably in the ears of the beholder. Should be an interesting conversation though.

[SonnyW]

FWIW, DiMarzio purposely adds spacers to create an air gap in their Air Norton and Air Zone models, and has a patent on it. It is supposed to reduce string pull, thus adding sustain. Patent: 4,501,185 & 5,908,998 I don't think it would make a profound difference though.

[JGundry]

Vintage P.A.F.'s often have a little gap between the magnet and the slugs. I think it is just a result of the assembly sequence used for vintage P.A.F.'s. A gap does have does have a tonal impact. Just think of it as another tonal tweak that you can manipulate.

[foonting]

FWIW, DiMarzio purposely adds spacers to create an air gap in their Air Norton and Air Zone models, and has a patent on it. It is supposed to reduce string pull, thus adding sustain. Patent: 4,501,185 & 5,908,998 I don't think it would make a profound difference though.

Hummm methinks DiMarzio would patent the sunrise if they thought they could get away with it! Yay, I could be accidentally infringing one of Larry's patents ... I knew there was a reason I got up this morning!
Having pulled up both these patents it appears that DiMarzio have been granted a patent on ferrous base plates ... as used on Tele bridge pickups ... and the 'reflector' plates used in the Wide Range. Better watch out guys, Larry'll get ya!

[David Schwab]

Having pulled up both these patents it appears that DiMarzio have been granted a patent on ferrous base plates ... as used on Tele bridge pickups ... and the 'reflector' plates used in the Wide Range. Better watch out guys, Larry'll get ya!

I don't see a patent for either of those things. What I do see is the steel plate between the top and bottom of a particular stacked pickup design. That's totally different.

I once examined a DiMarzio 36th Anniversary PAF. It was actually very interesting. The slugs were shaped just like the screws with a wide head and skinny shaft, so the two coils were balanced. They had small nylon washers around the outer four screws/slugs to act as a spacer for the magnet. Then they had additional steel slugs inserted between the screws/slugs from the bottom so you couldn't see them from the top. I thought it was quite an elaborate way to tune the pickup to the tone they wanted while looking like a stock PAF style humbucker.

[SonnyW]

I just quoted the patents listed on Larry's website without even researching them, but I believe the key word in those patents is "selectively positioned". Based on past info, I wouldn't want to take the bet that someone could get away with marketing a humbucker with a purposeful "air gap" to reduce string pull without getting flack of some variety from his lawyers. Just my opinion.

[David Schwab]

I just quoted the patents listed on Larry's website without even researching them, but I believe the key word in those patents is "selectively positioned". Based on past info, I wouldn't want to take the bet that someone could get away with marketing a humbucker with a purposeful "air gap" to reduce string pull without getting flack of some variety from his lawyers. Just my opinion.

I agree. I was commenting on the steel baseplate thing. You can certainly make a pickup with a gap between the magnet and poles, but I wouldn't try and do one that looks like a PAF and try and market it. The Q-Tuner pickup had a gap between its neo magnets and the poles.

That magnet gap patent was issued in 1995, so there's three more years before it expires.

One thought about this. I think it was DiMarzio's way of getting a softer magnetic field without going to an A2 magnet.