6 string bass

[bassystem]

Hi

I want to make pickups for my 6 string custom made bass. String spacing will be 19mm on the bridge, I consider making j and p configuration. I manage to buy only 41awg, so I'll try with that. Can someone tell me with what measurement should I start to experiment? Height of magnets and dimension of bobin? Number of winds? I'll try to make j bridge single coil and also j bridge split coil...p neck will be split coil of course. I have enough room for custom pickups any measures.

Thanks

[Antigua]

You get more output for less wire if the pickup is shorter and wider (like a P-90), especially if the pole pieces are AlNiCo, because the portion of coil that is further from the strings is less productive that the portion that is closer to the strings. It's easier to arrange for more of the coil to be closer to the strings if the wire is very fine, it will be harder with 41 AWG. No matter the gauge, the number of turns would be the same for a given overall inductance. Most Fender type single coils appear to be 7,000 to 8,000 turns and end up with an inductance between 2 and 3 henries for a given coil.

The available P-Bass pickups are a lot more random, because the coils are in series, and so the inductance of the two coils adds together, so if both coils have 8,000 turns of wire, then each might have an inductance of 2.5 henries, and the final inductance would be 5 henries. I've measures some P-Bass pickups as low as 3 henries and some as high as 6. It's a matter of preference, but if you want maximum treble available to then be attenuated with the tone control, it's better to aim for the lower inductance figure, so I'd shoot for maybe 4,000 turns per P-Bass coil and 7,000 for a Jazz Bass type, even if they're sized for a six string bass.

[bassystem]

ok, thank you for your answer...but what you think about size and position of alnico magnets (regardles bobin)? So I read that larger pieces will deliver higher output. But what about their position, would it sound better if they are close to strings, or in the middle of coil....or? And what is best, is it wrong if coil and magnets are not simetrical?

[Antigua]

ok, thank you for your answer...but what you think about size and position of alnico magnets (regardles bobin)? So I read that larger pieces will deliver higher output. But what about their position, would it sound better if they are close to strings, or in the middle of coil....or? And what is best, is it wrong if coil and magnets are not simetrical?

Larger, stronger magnets will get you more output. Just keep in mind that sometimes AlNiCo pole pieces are wider, but not taller, and what happens is if you make AlNiCo wider without also making it taller, it will generally become weaker, too, because, unlike most modern magnets, AlNiCo is dimension dependent, and it needs to be three to four times as tall as it is wide. So if you order wider diameter pole pieces, but they're the same height, they won't be that much stronger. Especially in the context of a bass guitar, the aperture of quarter inch or eight inch pole pieces doesn't differ enough to affect the sound, both are very "focused".

Symmetry doesn't matter much in and of itself, but depending on the context, it might matter. You want the coil to be fairly tight to the pole pieces so that the magnet field of the pole pieces and the coil will overlap. They less they overlap, the less efficient the pickup will be. If the coil's magnetic field intersects perfectly with both the primary and the return magnetic path of the pole piece, then you will have an efficient magnetic connection between the coil, pole pieces and the strings. The less they intersect, more magnetic cancellation you get, and so less voltage. The magnetic can technically be in a lot of places in or around the coil and still have good overlap, so long as the polarity of the magnet aligns with the field of the coil at that point in space (such as how a P-90's magnets are under the coil), but the classic Fender layout with the coil wrapped around the pole pieces is nearly ideal.

The end result will depend mostly on the inductance you end up with, and the value of the tone and volume pots. You can't really go wrong with the pickups so long as they're loosely based on the tried and true vintage layout. If you post a diagram of what you have in mind, its easier to comment on.

[bassystem]

I will, thanks