Translate 4-String J Bass Recipe to 6-String

[KindlyKiller]

Other than starting over from scratch with a sound in mind, are there any general guidelines/rules of thumb for translating a 4-string bass pickup's voice to a 5- or 6-string pickup? I can use that resistance calculator softare to figure out how many turns I need to get the same amount of wire, but I suspect that other things will change in the process. Any pointers?

[David Schwab]

Originally Posted by KindlyKiller

Other than starting over from scratch with a sound in mind, are there any general guidelines/rules of thumb for translating a 4-string bass pickup's voice to a 5- or 6-string pickup? I can use that resistance calculator softare to figure out how many turns I need to get the same amount of wire, but I suspect that other things will change in the process. Any pointers?

Well just the fact that the coil has a different dimension is going to change things, all other things being constant.

I wouldn't sweat it... wind the same number of turns and see what you get.

If you want the same resistance, I'd wind some and check it as you go... but I never check resistance until I finish anymore.

[Zhangliqun]

Don't you need the same number of turns which would mean a higher DCR to get the same results tonally and output-wise?

I've been wondering this in calculating for F-spaced humbuckers.

[David Schwab]

Well you know the length and diameter of a conductor effect the inductance... there's a formula for it, which I forgot a while ago!

I bet Joe Gwinn could chime in with some useful info.

[Joe Gwinn]

Originally Posted by David Schwab

Well you know the length and diameter of a conductor affect the inductance... there's a formula for it, which I forgot a while ago!

I bet Joe Gwinn could chime in with some useful info.

There are many formulas, but I don't understand the question well enough to decide which formula is most useful.

[Arthur B.]

Here's some http://en.wikipedia.org/wiki/Inductance for inductance. Pick which one you need.

[David Schwab]

Originally Posted by Joe Gwinn

There are many formulas, but I don't understand the question well enough to decide which formula is most useful.

What he wants to do is make 5 and 6 string Jazz Bass pickups, and have them sound the same as the smaller 4 string version. He made a point that counting turns will give you different results, since 1 turn around a 4.5" long bobbin will be more wire than 1 turn around a 3" bobbin.

Then you have a different number of magnets... that surely must do something to the overall tone of the pickup.

I'm not so sure that you can even made the two pickups sound exactly alike, and at the very same time I don't think they will sound different enough to matter.

Also, I have heard many bass players and builders who think that a 5 sting bass just doesn't sound like a 4 string... they seem to feel that the low E on a 5'er is not as punchy as on a 4 string bass.

I don't know if I agree, but I haven't played a 4 string bass in about 10 years. So my point being that even if you can make the pickups sound exactly the same, the basses probably won't. I even have two of the same model bass that I built, and they sound quite different. The main difference is the top wood.

Ah, the subtleties of building stringed instruments! Is it science or art, and is science and art truly different?

[Joe Gwinn]

Originally Posted by David Schwab

What he wants to do is make 5 and 6 string Jazz Bass pickups, and have them sound the same as the smaller 4 string version. He made a point that counting turns will give you different results, since 1 turn around a 4.5" long bobbin will be more wire than 1 turn around a 3" bobbin.

The same number of turns on a larger form will increase the inductance. The following standard formula isn't exactly right for pickup coils, being for long coils (length at least ten times the diameter of the core) with a single-layer winding, but it is simple and will give us the general behavior:

L = (4 Pi) N^2 A/l 10^-9

This yields henrys given the turns count N, coil length in centimeters l, and coil (well, core) area A in square centimeters.

Note that for constant turns count and coil length, the inductance is proportional to the enclosed coil core area. So, if one went from four strings to six strings by making the bobbin wider, going from 3" to 4.5", the inductance would increase by a ratio of about 4.5/3= 1.5 to 1.

The above analysis is an example of the use of "scaling laws" to estimate the effect of changes in situations where computing exact values is far too complex to be useful for understanding the general lay of the land.

Then you have a different number of magnets... that surely must do something to the overall tone of the pickup.

I would assume so, as there is added magnetic material and scope for eddy currents.

I'm not so sure that you can even make the two pickups sound exactly alike, and at the very same time I don't think they will sound different enough to matter.

I think one can get very close, but will soon run into diminishing returns.

Also, I have heard many bass players and builders who think that a 5 sting bass just doesn't sound like a 4 string... they seem to feel that the low E on a 5'er is not as punchy as on a 4 string bass.

I don't know if I agree, but I haven't played a 4 string bass in about 10 years. So my point being that even if you can make the pickups sound exactly the same, the basses probably won't. I even have two of the same model bass that I built, and they sound quite different. The main difference is the top wood.

Another cause of diminishing returns.

Ah, the subtleties of building stringed instruments! Is it science or art, and are science and art truly different?

Science and art are quite different, and one needs a bit of both to build a musical instrument.

[KindlyKiller]

Originally Posted by David Schwab

What he wants to do is make 5 and 6 string Jazz Bass pickups, and have them sound the same as the smaller 4 string version.

Yes.

I'll be making these tommorow. Thanks for the input. I knew it wouldn't be a simple answer.

[David Schwab]

Originally Posted by KindlyKiller

Yes.

I'll be making these tommorow. Thanks for the input. I knew it wouldn't be a simple answer.

Just try some things out. Go with your gut feeling! I wound a stacked Jazz pickup not long ago, and I just picked a number to wind to out of the air. Seemed like a good number at the time!

The pickup sounds good. I wasn't going for a particular tone, but I like the tone it gets just fine, so the point is you never know.

Another thing to ponder is you really want a pickup to reproduce the bass. I'm making some pickups with little coloration, and a wider response. They sound great with little to no EQ, and go much deeper than a usual pickup you would hear on a Fender.

So sometimes different can be better.