Wal style pickups AND question about winders

[David Schwab]

I bought an Ovation Magnum bass many moons ago and could never get a sound I liked out it, it was terrible IMO. I remember the neck felt ok but the thing just sounded bad. I ended up selling to help fund a 67 pbass.

Well it certainly didn't sound like a P bass. It was more in the Rick camp.

I tried out a Magnum II with the EQ circuit when they first came out. I was very impressed with it... it sounded like a piano. I didn't realize it at the time, but that was my first experience with a graphite reinforced neck.

[Triad]

You guys are leaving me aloooooone with my problem!

[David Schwab]

No, we are giving you ideas to solve the problem.

If you have an odd number of strings, and you are only doing one coil per string, then you need to add an extra coil. The magnet is not important, because there is no string over that coil. A steel core would suffice.

You can also split up the pickup into two units like a long P bass pickup.

[Triad]

So the options are:

11 coils wired around 11 magnets + a dummy coil to cancel hum (so the coils must be in pair, as I thought)

two coils, one with 6 and one with 5 magnets... and I'd put more wire on the smaller one to achieve a similar value

two coils with 11 magnets (hoping my winder doesn't die)

11 coils with 2 magnets each (but I'd need a dummy coil anyway)

Right?

[David Schwab]

11 coils with 2 magnets each (but I'd need a dummy coil anyway)

You can't have two different polarity magnets in one coil.

Your winder should be fine with long coils. I have the same winder.

[Triad]

Sure, I didn't plan to put N and S magnets in the same coil... I wanted to put 5 pairs N and 6 pairs S PLUS a dummy coil. But if you think the winder won't break I'll make two long bobbins and solve the problem

[David King]

Triad,
I think there is another option which I described above..
As long as the 5 coils match the 6 other coils in area inside the coils and match the mass of magnetic material inside the coils you *might* be OK. This is purely theoretical...

[Triad]

Thanx David. By the way, I've always loved your basses
I'll see what tomorrow will bring... maybe I'll simply wind two huge bobbins.

[Joe Gwinn]

Triad,
I think there is another option which I described above..
As long as the 5 coils match the 6 other coils in area inside the coils and match the mass of magnetic material inside the coils you *might* be OK. This is purely theoretical...

I would modify this a bit. What one must match is the sum of the area-turns products of the 5 coils to that of the 6 coils. If a coil has a slug core, its area-turns product is increased by a factor of about three. If a coil has a magnet core, the effect on area turns product will be small. In both cases, experimentation is needed, as the exact area-turns products and increase factors are hard to predict from theory.

[Triad]

Uhm... I use magnets poles, not bars and slugs.

[mkat]

Well it certainly didn't sound like a P bass. It was more in the Rick camp.

Yeah, sure was. I was much more comfortable with the pbass sound at the time, but I did like the Rick sound better than the Magnum.

I tried out a Magnum II with the EQ circuit when they first came out. I was very impressed with it... it sounded like a piano. I didn't realize it at the time, but that was my first experience with a graphite reinforced neck.

That's interesting, I think the active eq on this would be more to my liking. The documentation states that the bridge pickup in both I and II produces a piano like tone, but I didn't hear that in the one I had (Magnum I).

[Triad]

I ended up making the pickups in the good ol' way: two bobbins. They turned out huge but they work and even if they were a bit hard to wound now they're ok and ready to pot

[Mike Sulzer]

Resonance Frequency of single coil vs. multiple pickups

If you replace a single coil pickup with n coils, putting the same number of turns on each coil, you can expect the inductance of each of the n coils to be about 1/n times the inductance of the single coil. So if you put the n coils in series you get the same inductance as the single coil.

The capacitance of each of the n coils is lower than that of the single coil as well. So the resonance frequency with the n coils is higher than for the single coil. But this ignores the cable capacitance, which is larger than the the capacitance of the single coil pickup. So if you use the pickup without a preamp, using the n coils makes some, but not a lot, of difference to the resonant frequency of the system with the cable. This is because the the cable capacitance is larger, and therefore more important, than the pickup capacitance.

If you use a preamp, thus unloading the cable capacitance from the coils, then the resonant frequencies of both systems are increased, and that of the n coil pickup is very high. But the resonance of the single coil might be as high as you need in this case.

[Triad]

Both basses are passive...
I would have liked to try to make more smaller coils but I did fear to do something wrong about hum cancelling so I went for the "standard" pair of huge singles.