Stacked P90

[Lyrebird Steve]

Here you can see the bottom of the top coil shield.

The bottom coil is wound to 2.45k, and has no magnets. Instead, it has ten steel slugs, and it has no shielding. The slugs increase the inductance in the coil.

The two coils are wired in series.

SO ... in theory, you can stick one of these to the bottom of any existing single coil and get Hum Cancelling ??

[Bill Scheltema]

Hi guys,

I did a test P90 with an inner and outer coil. Inner wound to 5000 @ 3.78, Outer wound to 5080 @4.65.
Overall DCR was 8.43.
It was hum cancelling but weak and I think due to the magnet polarity.
Should there be a barrier between the coils instead of just tape, would that help at all.
I know that dean markley's acoustic soundhole pickups have an inner and outer coil so I guess its an issue with deciding how to arrange the mags.

[big_teee]

Hi guys,

I did a test P90 with an inner and outer coil. Inner wound to 5000 @ 3.78, Outer wound to 5080 @4.65.
Overall DCR was 8.43.
It was hum cancelling but weak and I think due to the magnet polarity.
Should there be a barrier between the coils instead of just tape, would that help at all.
I know that dean markley's acoustic soundhole pickups have an inner and outer coil so I guess its an issue with deciding how to arrange the mags.

[ATTACH=CONFIG]22684[/ATTACH]

Thanks for posting the info and the pics.
Did You try playing in a split mode?
Just one coil, the inside coil, and then just the outside coil?
Comparing the sound and volume in split to the humbucking mode.
I would think just the outside coil by itself would be weak.
Also I would think you would want to feed the start lead of the inside coil, for maximum volume.

[Bill Scheltema]

Big Tee
I didn't a/b each coil but I will.
I did use the inner coil as the start lead.
I was talking to a pup guy and he suggested 42Ga for inner coil with more windings, then 42Ga for outer with less winds.
Now to figure out just how many for the inner and the outer.
If I use 43 for the inner I can get more winds for sure.

Any thoughts

Bill

[big_teee]

Big Tee
I didn't a/b each coil but I will.
I did use the inner coil as the start lead.
I was talking to a pup guy and he suggested 42Ga for inner coil with more windings, then 42Ga for outer with less winds.
Now to figure out just how many for the inner and the outer.
If I use 43 for the inner I can get more winds for sure.
Any thoughts

Bill

Interesting.
How is it tied together.
feed the inside start lead, then tie the inside finish to what?
Where does it ground?
+inside start------------inside finish-outside finish--------------outside start to Ground?
Is it anything like that?

[BillScheltema]

Interesting.
How is it tied together.
feed the inside start lead, then tie the inside finish to what?
Where does it ground?
+inside start------------inside finish-outside finish--------------outside start to Ground?
Is it anything like that?

Inner coil start to ground, finish to outer start, outer finish hot/live. Both coils CW wound.
So then the outer coil should be wound larger than the inner?

Bill

[Lyrebird Steve]

Both coils CW wound.

Hmmm ... I've never done one like that but wouldn't you need CCW on one of them ?

[Bill Scheltema]

The inner coil finish end attaches to the finish end of the outer coil which makes it go CCW to its start lead.

Bill

[big_teee]

The inner coil finish end attaches to the finish end of the outer coil which makes it go CCW to its start lead.

Bill

For grins and giggles, I would want to try feeding the start lead of the inner coil.
If you feed the outer coil and the inner is in reverse, seems the signal is far from the magnets.
Especially if they are trying to cancel each other out.
So be sure and try and experiment with all options.
Sometimes things don't react like you think they should.
T