Bobbin rigidity and it's impact on tone

[verhoevenc]

I recently had a conversation with a guy that builds pickups that I admire. He seemed to stress bobbin, pole, coil, everything rigidity unlike I've read anywhere else. Anyone else have comments on this. By this I mean stiffer material for the flatwork, harder material for saturating the coils than wax, etc. etc.
Any thoughts from you guys?
Regards,
Chris

[big_teee]

I recently had a conversation with a guy that builds pickups that I admire. He seemed to stress bobbin, pole, coil, everything rigidity unlike I've read anywhere else. Anyone else have comments on this. By this I mean stiffer material for the flatwork, harder material for saturating the coils than wax, etc. etc.
Any thoughts from you guys?
Regards,
Chris

If you really want things rigid I guess he can encapsulate in Epoxy.
I don't want anything flopping around, but don't see any need to be any stiffer than normal parts allow.
Maybe David, Rick and some others can elaborate on this!
Good Luck,
Terry

[David Schwab]

I can't see the rigidity of the bobbin mattering much if the pickup is wax potted. Once the thing is wound and assembled the whole unit is pretty rigid. Were it might matter is in undesirable feedback. Some of the Gibson mini humbuckers had pretty flimsy bobbins.

I've made bobbins from a number of different materials, from printed circuit boards, to thin cardboard. They all sounded the same to me, even before I encapsulated them in epoxy.

The bobbin is just a coil former. Some pickups don't even use bobbins. Modern examples of these would be the hand wound Kent Armstrong pickups, and Q-Tuners. Both of those are epoxy encapsulated, but older pickups like the Burns Tri-Sonic was not.

[Rick Turner]

I, for one, have gone back to wax for potting...paraffin is almost as good an insulator as Teflon. So in potting a coil, you're both solidifying it as well as changing the insulating quality of the space between the copper turns.

This kind of question shows what happens when you zoom in so narrowly on one aspect of a pickup (or guitar design, or whatever) that you totally ignore other perhaps equally or greater issues.

This also my verge on the smoke and mirrors bullshit that becomes something to tell your customers that sounds like deep science and could be utter nonsense. There is so much quasi-science in lutherie it's just ridiculous.

[Peter Naglitsch]

On the other hand some people hear a difference between potted and unpotted pickups. Adna an unpotted coil could easily be said to be quite "flimsy". So if that makes a difference maybe a sturdy coil former (bobbin) will have an impact. Hmmm, need to experiment with this.

[JGundry]

If the pickup is potted the mechanical frequency of the pickup is basically a dull thud no matter what the bobbins are made of. If a pickup like a humbucker is unpotted then I think the mechanical resonance of the entire assembly does have some impact on the tone. The hardness of the bobbins would have some impact in that circumstance. Harder or softer might sound a little different but which is better?

[verhoevenc]

It's interesting that you say that, cause they mentioned a varnish-as-you-go method of sealing up the coil to avoid microphonics, instead of later wax potting. Both do the same thing in terms of dealing with microphonics, however the wax I'm sure adds more weight, not to mention different physical characteristics than varnish, which like you said may be impacting tone through mechanical resonance. I'd hazard to say wax is a more cushioning/absorptive substance substance than varnish.
Chris

[David Schwab]

If the pickup is potted the mechanical frequency of the pickup is basically a dull thud no matter what the bobbins are made of. If a pickup like a humbucker is unpotted then I think the mechanical resonance of the entire assembly does have some impact on the tone. The hardness of the bobbins would have some impact in that circumstance. Harder or softer might sound a little different but which is better?

I tried tapping a few epoxy encapsulated pickups (mine and EMG), and a few standard humbuckers (Duncan and DiMarzio) and they both sound like a thud. The encapsulated pickup makes a higher pitched thud.

If the standard humbucker bobbins had a resonance, which they don't, it's lost once you wind wire on them. Now you are hearing the mass of wire, which sounds like a thud. And that doesn't even bridge the baseplate, etc., into it. A softer material for a bobbin would have even less of a resonance when tapped.

[David Schwab]

It's interesting that you say that, cause they mentioned a varnish-as-you-go method of sealing up the coil to avoid microphonics, instead of later wax potting. Both do the same thing in terms of dealing with microphonics, however the wax I'm sure adds more weight, not to mention different physical characteristics than varnish, which like you said may be impacting tone through mechanical resonance. I'd hazard to say wax is a more cushioning/absorptive substance substance than varnish.
Chris

No, wax does not add more weight. They are about the same, and the vanish might be heavier. The varnish also does not dry well most of the time on the inside of the coil. That's why I stopped using varnish.

However they sound exactly the same in the context of a pickup, which is to say they add nothing to the sound. They just secure the wires from vibrating.

[big_teee]

There's so many more things that effect tone than stiffness or potting.
I never heard or thought of using stiffness or potting as a big selling point to sell pickups.
"Like mine sound better than yours because they are stiffer and waxier, or have more varnish"!
Like I said There are a lot better selling points, I would think than Stiffness.
Like the kind of wire, the amount of wire, the height of bobbins, the Magnets, and gauss used to name a few. etc.
Rick Nailed it, more Smoke and Mirrors!
Terry

[verhoevenc]

Well the reason I took heed of the advice was cause they don't use it as a selling point... this is merely something they told me when I drilled them about their processes so that I could replicate something similar.
Chris

[Rick Turner]

I did hear a difference when I went from superglue potting coils to shellac...which, as has been implied here in reference to varnish, dries too slowly. Then I went back to good old (and easy) wax. There are little mechanical resonances that can affect tone. Anything that couples motion to coil turns and lets them vibrate relative to the magnetic field makes a pickup microphonic...part of it becomes a moving coil pickup. Paraffin and bees wax have good vibration damping characteristics, so I consider that a good thing. If you know your turns count accurately and can hold DCR to a good tight spec, then you know that your coils are wound under consistent tension. If you then pot them, they should sound incredibly alike.

[big_teee]

If you really want to hear Microphonics at its best put a steel baseplate on the bottom of a strat or tele pickup, and not have it potted, or come loose.
I did that yesterday, my wax came loose, and you could touch the guitar anywhere and it made racket.
I could flip the selector switch and it made lots of noise.
Still I had to crank up the gain and volume and get fairly close to the speaker to make it squeal.
I heated up the baseplate so the wax restuck, and all was quiet.
Terry

[David Schwab]

One thing I want to add is I think the individual parts' resonance isn't as important as vibrations coupling into the pickup as a whole. Also I wonder if the coil vibrating vs. the poles/magnet vibrating can be differentiated. So even if the coil is rock hard, vibrations coupled into the steel parts might have the same affect.

But these are just my thoughts on it.

You also have to wonder if super glue sounded different from wax because of the dielectric properties of each, or the amount of padding and thus distance between the wire strands. Waxed coils seem fatter than CA, which I tried once or twice.