Humbucker Output Question

[PoorMan]

So...Relating to coils only and all things being equal...output is determined primarily by the number of winds. (Forget magnets and such for a minute).

I've wound many humbuckers with "x" number of winds and 42AWG SPN. I decided to experiment with Single Build PE and Heavy Formvar (still 42AWG) and did the same number of winds, but the DC Resistance was 0.61 higher. (Oddly, the PE coils and Formvar coils came out with the exact same resistance. Coincidence? I found that interesting, but it's not the point of my post so...)

My question is this: since the number of winds is the same as my SPN humbuckers, should I expect the output to be the same regardless of the fact the DC resistance is so much higher? Or does the DC resistance somehow indicate more output? I think not...but it was a big difference so I thought I'd ask the question.

[Joe Gwinn]

So...Relating to coils only and all things being equal...output is determined primarily by the number of winds. (Forget magnets and such for a minute).

I've wound many humbuckers with "x" number of winds and 42AWG SPN. I decided to experiment with Single Build PE and Heavy Formvar (still 42AWG) and did the same number of winds, but the DC Resistance was 0.61 higher. (Oddly, the PE coils and Formvar coils came out with the exact same resistance. Coincidence? I found that interesting, but it's not the point of my post so...)

My question is this: since the number of winds is the same as my SPN humbuckers, should I expect the output to be the same regardless of the fact the DC resistance is so much higher? Or does the DC resistance somehow indicate more output? I think not...but it was a big difference so I thought I'd ask the question.

DC resistance has little effect on output voltage, unless the coil is loaded too heavily by the volume and tone control pots. If two coils have the same number of turns, but the wire on one has heavier insulation (so the coil takes more space), both coils will have approximately the same DC resistance, the more tightly wound coil may have greater output (and slightly larger DC resistance because average turn is longer), but I don't know how big an effect this is in practice.

[Ruel]

The diameter of the wires will also affect the DCR readings but I don't think they will be enough to affect the outputs.

[Robert M. Martinelli]

So...Relating to coils only and all things being equal...output is determined primarily by the number of winds. (Forget magnets and such for a minute).

I've wound many humbuckers with "x" number of winds and 42AWG SPN. I decided to experiment with Single Build PE and Heavy Formvar (still 42AWG) and did the same number of winds, but the DC Resistance was 0.61 higher. (Oddly, the PE coils and Formvar coils came out with the exact same resistance. Coincidence? I found that interesting, but it's not the point of my post so...)

My question is this: since the number of winds is the same as my SPN humbuckers, should I expect the output to be the same regardless of the fact the DC resistance is so much higher? Or does the DC resistance somehow indicate more output? I think not...but it was a big difference so I thought I'd ask the question.

The main factor in pickups' windings is always inductance, and all other factors being equal, it grows with the winding number squared. If other factors differ, you' ll have different behaviors, e.g. if the coating has a different dielectric constant, and a different thickness, the overall parasitic capacitance will change, together with inductance shifting the resonant peak consequently. With loose windings, or with a wire of same AWG but thicker insulation, you' ll have a lower inductance and parasitic capacitance, so, even if the number of windings stays the same, your resonant peak will be higher, the output lower, and the Q factor worse ( due to smaller inductance - smaller capacitance and a somewhat higher DC resistance due to the fact that the winding will be longer, as Joe said ).

All the above neglecting - as per your post - the effect magnets have, which is twofold - first of all they' re the "motor" that makes pickups work, so, all other factors kept equal, the stronger the magnets, the higher the output.
(e.g. a standard Fender pickup, which has a coil in the range of 7800 windings, 2,2 H, 6 KOhm and 100 pF, which makes for a high resonant peak, a high Q, a sparky and glassy sound, due to low inductance, capacitance and DC resistance, has pretty strong magnets to bring the output to a decent level ).

secondly, since magnetic permeability varies with magnets' material, they tend to behave differently with respect to frequency ( e.g. - to my knowledge, ceramic magnets have a very high permeability at higher frequencies, boosting highs, and this could be the reason someone says they tend to sound "harsh", especially with "short" windings, this is why they' re best suited for high output pickups with a much bigger number of turns - e.g. Duncan Dimebucker - the bigger number of turns brings down the resonant peak to lower freqs and increases output ).

Hope this helps

Best regards

Bob

[kevinT]

Great post Bob!

Thanks!!!

[Robert M. Martinelli]

Great post Bob!

Thanks!!!

Hi Kev,
I try to share the little I know, for me this is difficult for two reasons: First of all it' s always hard to "squeeze" a lot of info in a reasonably short post; second, English is not my native language. So, it' s me thanking YOU for your kind reply, and, please, feel free to correct my mistakes, to help me keep improving my English.
Best regards
Bob