Pickup theory question

[Jeff Callahan]

Merry Christmas and happy holidays,

Assuming all else is constant, how much more would one have to wind on an A2 pickup to match the same output (voltage) as an A5 pickup. Fully charged magnets and same bobbin, wire, etc. Let me know if I'm missing something here, I know this oversimplifies things, but I'm hoping for some kind of equation, or rule of thumb.

Thanks,
Jeff

[Rick Turner]

I don't think you'll find it quite that easy. There will be a different kind of geometry to the magnetic field, too, and distance of string to pickup will be a factor as well.

I'd suggest that you simply wind and test, wind and test. That's how research is done.

[Jeff Callahan]

Damn, thought I'd get lucky!

I'll be winding soon, but wanted a jump start. Different grades of Alnico have different geometry? Didn't see that one coming. As for the pickups height, and string vibration (neck vs. bridge), that can be controlled.

Thanks,
Jeff

[Rick Turner]

The shape and density of the field will be different when you go from one type of magnet to another. Therefore the interaction with the strings will be different and the induced magnetism in the strings will also be different.

There are few short cuts in all of this. You've just got to make, wind, and listen. Then try to document and learn how each change affects what you hear.

[David Schwab]

Turns equals output. I've never heard a volume difference between A2 and A5, but the A5 is brighter so it might sound louder.

[FunkyKikuchiyo]

"output" tends to be a more emotional, personal description than an empirical one despite what some major manufacturers may offer as data, and if in the process you can find a good quantitative way to measure output then I think you'll win lots of respect!

I usually "measure" output of a pickup by approximating an ideal height (a "high output" pickup that you can't get close to the strings won't really be high output, will it?) and a/b-ing it with some known stock pickups of another instrument, or on the same instrument with the flip of a switch. For my purposes this works just fine. For my porpoises, typically a bucket of chum. Okay, too late at night to be posting this stuff, methinks...

[Mike Sulzer]

Turns equals output. I've never heard a volume difference between A2 and A5, but the A5 is brighter so it might sound louder.

Turns equals output. I've never heard a volume difference between A2 and A5, but the A5 is brighter so it might sound louder.

No, turns does not equal output; it is one factor. Magnetic field strength at the string is another. A stronger magnetic field magnetizes the string more strongly and results in a higher output. This holds up to saturation, and it would take very strong magnet indeed to saturate the cores or the string. For example, using large neodymium magnets on the cores results in very high output, but terrible string pull.

How does changing the type of Alnico change the field geometry significantly? This is a subject for simulation with FEMM. But even if it did, so what? It is only the field strength at the string that matters.

[copperheadroads]

Turns equals output. I've never heard a volume difference between A2 and A5, but the A5 is brighter so it might sound louder.

I agree
I don't think you can say one magnet type has more output than others ,But they do have qualities that can give you a bigger & or brighter & or bassier sound
You can adjust an alnico 2 pickup a little closer to the strings compared to an A5

[Peter Naglitsch]

Turns equals output. I've never heard a volume difference between A2 and A5, but the A5 is brighter so it might sound louder.

No, turns does not equal output; it is one factor.

C’mon Mike, you know what David means. If everything else is kept as is and you just add turns there is a linear correlation between turn count and output.

[Mike Sulzer]

C’mon Mike, you know what David means. If everything else is kept as is and you just add turns there is a linear correlation between turn count and output.

Peter, I did read, and still read, both David and copperheads saying that different magnets make a qualitative difference in the sound, but do not affect the out level.

[Peter Naglitsch]

Mike, there is no reason to always get into petty debates over details. My over all message was; you know David didn’t mean that turn count was everything, still you needed to push things into a debate. You did even quote him on “I've never heard a volume difference between A2 and A5, but the A5 is brighter so it might sound louder” Re-read that and you might see the word “heard” and that’s the key point here. You can debate as much as you will but you cannot push an opinion on anyone and if someone hears a difference that difference is true to that person and he/she will use that information to build pickups.

[Mike Sulzer]

Mike, there is no reason to always get into petty debates over details. My over all message was; you know David didn’t mean that turn count was everything, still you needed to push things into a debate. You did even quote him on “I've never heard a volume difference between A2 and A5, but the A5 is brighter so it might sound louder” Re-read that and you might see the word “heard” and that’s the key point here. You can debate as much as you will but you cannot push an opinion on anyone and if someone hears a difference that difference is true to that person and he/she will use that information to build pickups.

There are plenty of petty debates on this forum. You rarely comment on them unless I am involved in what you consider a petty debate. Why?

But this is not a petty debate, and there are facts involved here, not just opinions. JC asked a question and he deserves answers. If one answer gets the facts wrong or over simplifies things so it the wrong conclusion appears correct, then there is nothing wrong with correctling that.

These things matter. For example, suppose you use a much stronger magnet in a humbucker than a standard one. The pickup gets louder if you keep everything else the same. This is an observed fact, and it is consistent with the theory of how magnetic pickups work. This is the kind of thing that serves as a mental "anchor" in designing pickups: when theory and observation agree, you should believe the result and use it. If they do not agree, then you have to resolve the contradiction.

Now suppose when you used the much stronger magnet and kept everything else the same, but you have introduced unsatisfactory "string pull" or stratitis. Now lower the pickup until that disappears. Does the original pickup or the one with the stronger magnet have the higher output level now? Why?

[Joe Gwinn]

I would suggest that because there is a limit to how strong the magnetic field can be without causing undue string pull and thus stratitis, that magnet size and so on have evolved such that the field at the strings is more or less constant, whatever the magnetic material being used.

That said, there are some pickup designs with notable weaker fields, by intent, so this is a different evolution.

[Mike Sulzer]

I would suggest that because there is a limit to how strong the magnetic field can be without causing undue string pull and thus stratitis, that magnet size and so on have evolved such that the field at the strings is more or less constant, whatever the magnetic material being used.

That said, there are some pickup designs with notable weaker fields, by intent, so this is a different evolution.

Humbucker magnets come in pretty much a standard size, but made of different materials (different alnico grades, ceramic). It would be interesting to know how much difference this really does make in field strength at approximately the string height.

[Peter Naglitsch]

There are plenty of petty debates on this forum. You rarely comment on them unless I am involved in what you consider a petty debate. Why?

Yes I generally stays out of silly debates. I should have stayed out of this one too as I had a feeling were it is heading...

And don't imply that I'm out for you personally. That suggestion is just daft. Check my posts to see if I'm a troll or not

I'm out of here. Have guitars to build and pickups to wind. IRL