Pickups for P + double coil J bass

[Marco Pancaldi]

Hello,
I want to make a P + doubleJ pickup set for my old Yamaha 4 string fretless. I'd wish a transparent, acoustic-like tone, with well matched output between P and doubleJ position. I want no hum in every setting, so the J will be a permanent humbucker.

I'd like to play with AWGs: for example, making the two J coils one AWG42 and the other AWG43, and maybe the P also with 42/43 (to make the G-D coil fatter sounding).
I've noticed that Nordstrand winds his DoubleCoils differently for series OR parallel use: I think in my case series is better - the PU will have more mids to make the fretless notes sings better, and probably this is a better match with the traditional series-connected P.

So, what you think about the AWGs, and have you advices about turns number?
Thanks
m.

[Mike Sulzer]

If you put two coils in series, over the bandwidth of a bass speaker they behave as a single entity. I do not see how making the coil resistances slightly different by using different size wire can have any audible effect at all.

Hello,
I want to make a P + doubleJ pickup set for my old Yamaha 4 string fretless. I'd wish a transparent, acoustic-like tone, with well matched output between P and doubleJ position. I want no hum in every setting, so the J will be a permanent humbucker.

I'd like to play with AWGs: for example, making the two J coils one AWG42 and the other AWG43, and maybe the P also with 42/43 (to make the G-D coil fatter sounding).
I've noticed that Nordstrand winds his DoubleCoils differently for series OR parallel use: I think in my case series is better - the PU will have more mids to make the fretless notes sings better, and probably this is a better match with the traditional series-connected P.

So, what you think about the AWGs, and have you advices about turns number?
Thanks
m.

[David King]

Marco,
For the J halves to match the P halves you need to have equal turns*areas. A p pickup will have 10000 turns and a thinner top to bottom coil so the outer turns will be much larger area than a skinny tall j coil. You might want 43 on P to minimize turns*area and 42 on the J to maximize it so that you don't have to wander too far off into 10000+ turns area. If you do go with say 11000 turns on the J it might balance just fine despite limited string excursion due to longer magnets.

[Marco Pancaldi]

If you put two coils in series, over the bandwidth of a bass speaker they behave as a single entity. I do not see how making the coil resistances slightly different by using different size wire can have any audible effect at all.

Hello Mike,
thanks. If I understand correctly, your opinion is that the coil mismatching sometimes used in guitar humbucker to obtain a more open tone, in a bass context (instrument + amplification) is not really appreciable? Thanks.
m.

[Marco Pancaldi]

Marco,
For the J halves to match the P halves you need to have equal turns*areas. A p pickup will have 10000 turns and a thinner top to bottom coil so the outer turns will be much larger area than a skinny tall j coil. You might want 43 on P to minimize turns*area and 42 on the J to maximize it so that you don't have to wander too far off into 10000+ turns area. If you do go with say 11000 turns on the J it might balance just fine despite limited string excursion due to longer magnets.

Hello David, thanks.
From your answer I understand you think 10k turns of AWG43 (each coil) in the P pickup is well matched from a 11k turns of AWG42 in a single J, correct?
And in case I'd wish to use both jazz coil in series, how much turns in each J coil you think ia a good match with the P pickup?
Thanks,
m.

[David King]

Hi Marco,

I haven't actually done the math but Salvasan's coil estimator (which I found here: http://www.jdguitarworks.com/coil/coil.html) can do that for you once you've chosen the coil geometry and wire gauge/insulation thickness for each pickup.

[Marco Pancaldi]

Hi Marco,

I haven't actually done the math but Salvasan's coil estimator (which I found here: http://www.jdguitarworks.com/coil/coil.html) can do that for you once you've chosen the coil geometry and wire gauge/insulation thickness for each pickup.

Hello David,
the Coil Estimator is very cool, thanks!
I searched the forum about "turns x area" infos but found no right answers, sorry: how you compute the area?
Is it coil lenght x width, but i need to subtract the core (magnets/poles) area in some way? And how to add the coil height to the calculation?
Thanks,
m.p.