Wal style pickups AND question about winders

[Triad]

Hello! I have a doubt...
I know for sure that Wal basses have special pickups... every pole magnet has its own bobbin so for a 4 strings pickup there are 8 bobbins (I guess they're wired in series).

I've owned several Wals and didn't notice a very particular sound without the preamp tweaked. So the question is (for the ones who tried this solution): more smaller bobbins give a darker sound? What's the difference for the ear?
I'm asking 'cause I have to wire a couple of huge humbuckers and I'm looking for a solution. The bobbins would be very long and I'm worried... too much weight could damage my winder AND I don't know if I'd be able to keep the wire with the right tension without breaking it (every turn would take a lot of wire so I'd have to feed the bobbin very fast). Thanx in advance!

[belwar]

Hello! I have a doubt...
I know for sure that Wal basses have special pickups... every pole magnet has its own bobbin so for a 4 strings pickup there are 8 bobbins (I guess they're wired in series).

Correct... On the older Wal (The Pro basses) the top row of coils were wired together in series, then the bottom row were wired in series, then the two rows were connected together in series as well (End lead to End lead). The Modern ones such as the MKII and MKIII have the two coils for EACH STRING in series, and they are then added at the pre-amp.

I've owned several Wals and didn't notice a very particular sound without the preamp tweaked. So the question is (for the ones who tried this solution): more smaller bobbins give a darker sound? What's the difference for the ear?

Thats the million dollar question. I'm building a Wal based pickup right now.. I cant comment on what the changes would be, because frankly I lack the skill to determine that without testing.. However I have some opinions..

- Having individual coils, puts more wire closer to the pole piece and the magnetic field. This should in theory increase the treble.

- If I understand it correctly, one of the factors that alters Inductance is increasing the number of turns of wire around an inductor. The wal pickup has very high inductance. Of course it also has 80,000 turns of wire. Altering the inductance is going to alter the tone. Though im still experimenting to determin its effect.

I'm asking 'cause I have to wire a couple of huge humbuckers and I'm looking for a solution. The bobbins would be very long and I'm worried... too much weight could damage my winder AND I don't know if I'd be able to keep the wire with the right tension without breaking it (every turn would take a lot of wire so I'd have to feed the bobbin very fast). Thanx in advance!

Individual coils would certainly be a solution, and probably a good one too. I assuming your winding some something like an 8 string bass? If you wind slow you shouldn't have a problem with weight. You're still probably talking no more than a 1/4 pound. You could also create a split coil bucker, a-la P-Bass, but makybe with 4 coils. You could also increase the wire gauge to 43 or 44 and wind less. When you wind you could use multiple pieces of felt for tension.. each one with just a tinch of tension on it. that should smooth out the whiplash of the wire... and again wind slooooww.

[Triad]

I have to build two... well... two ELEVEN STRINGS basses
They're ready for the pickups and I'm trying to find the best solution.
With individual string humbuckers (two poles for each strings) I was thinking to wire them all in series (the basses will be passive), 5 pairs with North Up and 6 pairs with South up - to achieve hum cancelling.
Wasn't series wiring END to START? END to END wasn't for parallel?

[belwar]

Here i'll try to explain it this way.In the case of the Wal Pro Bass, the top four coils were put in series together.. For the sake of expediancy I'll refer to the Start Wire as "S" and the End Wire as "E".. If I say "E2" I mean the "End Wire of Coil 2"

The rows are wired like this... a Dash represents a soldered connection

S1 E1-S2 E2-S3 E3-S4 E4

S5 E5-S6 E6-S7 E7-S8 E8

That effectively makes two coils wound in series. They are then connected in series again with a connection between E4 and E8. Making the coils reverse wound.

Does that help?

[Triad]

Sure... thanx
So you think that two huge bobbins with 11 magnets could be wound without destroying my small Schatten winder?
Soundwise... I guess 11 small bobbins in series are gonna sound pretty different from two large bobbins... but I'd use the same number of turns. Example? 11 bobbins with 6000 turns each or two large bobbins with 11 magnets and 6000 turns each.

[belwar]

Can you post a picture of your winder?

Can you wind the pickup WITHOUT the magnet in?

[David King]

I have to build two... well... two ELEVEN STRINGS basses
They're ready for the pickups and I'm trying to find the best solution.
5 pairs with North Up and 6 pairs with South up - to achieve hum canceling.

That won't do it but you can just add a dummy coil with an un-magnetized magnet inside the bass that's aligned in the same orientation so you have 6 + 6.

For the long bobbins, just remove the pulley on the Schatten motor and let the belt run right on the motor shaft, that will slow it down and give it more torque.

I guess I can't see why the length of wire is going to be that different whether you wind 11 individual coils vs one long one.I also don't see how the inductance is going to change substantially since the same quantity of magnetic material is enclosed within the same number of turns. (Joe?)

I agree that more of the wire will be closer to the magnets in the single string version and that should make them brighter over all but with only 6 K turns you might not hear the difference.

[Triad]

The winder is pretty close to the one actually sold by Stewmac... but it's older.
How could I wind the bobbin without the magnets in? I guess that, if I found a way to do it, puttin the magnets inside could be challenging.

[Triad]

They must always be in pairs (one North and one South) for hum cancelling?

[David King]

They must always be in pairs (one North and one South) for hum cancelling?

Well not strictly;
A) You could wind 18% more turns on the 5 North than on the 6 South.

B) The 5 North could use larger magnets (perhaps best for larger strings anyway) and the coils could then cover 18% more area than the 6 South coils. (I think you'd want the 5 large magnets to weigh in about as much as the 6 smaller magnets.)

[David King]

The winder is pretty close to the one actually sold by Stewmac... but it's older.
How could I wind the bobbin without the magnets in? I guess that, if I found a way to do it, puttin the magnets inside could be challenging.

You could find some rigid thin-walled tubing that the magnets fit perfectly into. Build your bobbin around the tubing as spacers between the flatwork. And then insert the magnets in after you've wound the coils.

Alternatively you could make dummy slugs out of acetal (delrin)® and then pop them out one at a time and replace them with the magnet.

[Triad]

Understood... but this is for a 5+6 configuration, right?
If I'm going to use 11 bobbins, one for string, and want to wire them in series and achieve hum cancelling... can I put (for example) 5 pairs with North up and 5 pairs with South up?

[David Schwab]

There are very simple ways to make the bobbins using off the shelf parts. Here's one way. Hint, think nylon.



Regarding smaller coils. In the Bartolini patent #3983778, he states:

Above the resonant frequency, the impedance is influenced by the capacitive effects between turns of the coil and between layers in the coil winding. Specifically, the changing current in one turn of the coil influences the current in the neighboring turns of the coil. This effect becomes larger with increasing frequency such that the coil behaves as a capacitive reactance with turn-to-turn capacitive leakage to ground. Accordingly, the output signal from the sensing coils falls off rapidly above the self-resonant frequency.

Since both the inductance and capacitance of a sensing coil vary linearly with its mean radius, replacing one coil by multiple small coils can reduce the impedance of the pickup system by a factor equal to the number of coils and raise the self-resonant frequency by a factor equal to the square root of the number of coils.

He wasn't the first to use this either. For bass pickups, Gibson had this:



And Ovation had the Magnum. That bass was way ahead of its time.

[Triad]

Nice!
So if I don't want to use full lenght bobbins I guess I could definitely use smaller solutions.

Is this solution ok? 11 bobbins, 2 magnets each, 1 bobbin for string. 5 North and 6 south. Would they cancel hum?
Alternatively I could use bigger magnets using the same layout of the Ovation, more or less. But should I have the same number of magnets North and South to cancel hum? I guess not... but not sure.

[mkat]

And Ovation had the Magnum. That bass was way ahead of its time.

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.