PAF (and repro) magnets - an observation and questions I've always wondered about.

[real59er]

Hi folks,

I have read with great interest about the Joe Bonamassa custom shop pickups, and, in particular, that fact that they have alnico III (bridge) and II (neck) magnets. The Gibson CS Beanoburst "reissue" also has A3s, and so does the Kossoff model. The latter two guitars, to me, produced among the best classic LP tones ever.

My question is this. How did they all decide on A3s? Coincidence?

And I have two related questions:

When Seymour Duncan "recreates" a pickup, does he put in the same magnet as the original? And - this I've always wondered - How can anyone tell what kind of magnet is in an old PAF? AFAIK, there are no markings to tell.

I eagerly await anyone's insights as I have been pondering this for some time!

 

[Zhangliqun]

Re: PAF (and repro) magnets - an observation and questions I've always wondered about

In Seymour's view, at least last I checked, you can duplicate the sounds of A4 and A3 by various levels of aging/degaussing A5's or A2's. Thus to my knowledge he doesn't make an A4 or A3 humbucker, at least not outside the Custom Shop. (Evan -- or anyone else in the know -- naturally feel free to correct me.) To my ear FWIW, A3 and A4 tones can't be duplicated by aging either 5 or 2.

As for why did they all suddenly decide on A3, if you're thinking that A3 has this magic elixir that will solve most PAF-clone tone problems, it's just not so. They chose A3 as just one of many aspects of the overall design of their pickups. Apparently they felt that combined with their choice of wind pattern, tension, wire gauge and insulation, materials (especially the particular alloy of the steel parts), whether it will have a cover, and many other factors, the drier, chimier quality of A3 (relative to A2 and A4) would work best. In another PAF clone, even made by the same manufacturer, A3 might well be the worst choice in their view. The magnet is important but it's still just one of many ingredients.

As for how to tell the Alnico grades apart without markings, A5 is pretty easy to tell from 2, 3 and 4. Fully or nearly fully charged it will be very noticeably harder to pull off of your refrigerator. How to tell 2, 3 or 4 apart visually or with the ol' fridge test, you tell me. They look exactly alike to me (maybe some with a supertrained eye can tell), and they're close enough in tone that you could easily mistake one for the other sonically because one might be charged less, or in a pickup that inherently accents the tonal qualities of the other. They also all feel about the same to me on the fridge test.

In other words, if you have a bunch of A2's, 3's and 4's and drop them all in a pile together, you have a big problem...

 

[jeremy]

Re: PAF (and repro) magnets - an observation and questions I've always wondered about

To my ear FWIW, A3 and A4 tones can't be duplicated by aging either 5 or 2.

i very much agree with this.

im an alnico II junky but i use a2, a3, a4, and a5 in humbuckers depending on what tones the customer wants

 

[blueman335]

Re: PAF (and repro) magnets - an observation and questions I've always wondered about

My question is this. How did they all decide on A3s? Coincidence?

Certainly seems like more than a coincidence. A3's have been a very under-utilized magnet, and it's odd to see them in anything, let alone several in a relatively short time period. Like any magnet, it has it's uses, and A3's evidently have some untapped potential. I had ruled it out as a bridge magnet, but in seeing these new introductions it has me thinking; those mids and softer high-end make sense for the bridge slot, especially in a PAF. Going to have to that try that...

 

[real59er]

Re: PAF (and repro) magnets - an observation and questions I've always wondered about

Thanks for the replies. Interesting. I am well aware that the overall sound of any given pickup is the result of a complex interaction of many elements, including the magnet. Here's what I understand from your posts:

In an old PAF, the only way to tell Alnico grades is by magnet strength, A5 being clearly stronger than A2, 3 or 4 , the latter three being essentially similar in that regard. So noone can really tell if a pickup has an a2 3 or 4.

However, we know that each grade has certain tonal properties. One could train oneself to identify these differences by, say, taking one pup, and switching magnets and listening to any differences through the same setup. Any differences in tone would be attributable to the mag, since no other factors are changed. Bear with me here. Just trying to sort out things I've been thinking about for a while.

Now, from Zhang and Jeremy's posts, and what I've read elsewere, there appear to be two schools of thought. One, reportedly held by Seymour, is that differences in magnet response or tone can be simulated or compensated by other construction factors. DiMarzion evidently also holds this view (airbuckers etc).

Others, such as Zhang and Jeremy, appear to disagree. What I conclude from this is that if certain tonal properties are associated with a mag, and one hears those properties, we know that:

A. That pickup either has that magnet in it, or the combination of structural elements create that sound (Seymour school of thought) or;

B. If one hears the tonal properties of a given magnet in a pickup and this cannot be recreated through other factors such as winding, degaussing etc. (Zhang and Jeremy school of thought) then we can logically assume we are hearing that mag.

Which brings me back to my "coincidence" question. Could it be that the experts at Duncan and Gibson chose that mag (A3) because they heard that magnet's tonal properties in the source guitars?

And exactly how are pups reverse-engineered. Do designers mostly use their ears? For example, we know that Seymour examined Pearly Gates the guitar in great detail to come up with the namesake pups. How far do they go in the analysis. They can't take the pups apart, can they? Sorry if this is a bit tedious, I'm just trying to get clear objective info to sort out the facts and understand how this all works in a bit more detail!

Cheers!

 

[LtKojak]

Re: PAF (and repro) magnets - an observation and questions I've always wondered about

Could it be that the experts at Duncan and Gibson chose that mag (A3) because they heard that magnet's tonal properties in the source guitars?

The magnet is one of the variables, although one of the most important, if you ask me.

And exactly how are pups reverse-engineered. Do designers mostly use their ears? For example, we know that Seymour examined Pearly Gates the guitar in great detail to come up with the namesake pups. How far do they go in the analysis.

This is a trade secret. Anyway, Duncan and Kevin Beller have developed a process that can take a "tone imprint" from any p'up, so it's feasible to accurately reproduce it even with slightly different materials, compensating with coil geometry and TPL.

But the "fine-tuning" is always made by ear. Search for the "Joe Bonamassa" p'up set, there's a lot of good info about the process.

HTH,