DiMarzio Dual Sound as a single coil...

[jasyr]

Hi, i love my late 70's DS in single coil mode... and want to buy another & separate the coils to place 1 of them in a P90 cover. And keep the tone of the single coil.

My questions are:
Should i keep the magnet in the same place? Or can i put it under the coil to save room?
Will the tone change from the bottom plate capacitance being connected to only 1 coil?
Can i go without a bottom plate by measuring the capacitance of the-- i think brass alloy-- and compensate that way?
Can i saw the bottom plate in half and double it up to save room? will that change the sound or magnetic field?

Any other tips for this sort of operation?

Thank you much,

jasyr

[David King]

jasyr,
I can't imagine that there would be any significant capacitance from the bottom plate so your main focus should be getting the magnets right. Removing one coil and it's iron core will probably completely change the sound since the magnetic aperture will become much narrower. There's really no knowing what will happen until you try. I'd start by pulling the screws from the inactive coil and see if that changes the sound of the active coil. Since the magnets are ceramic you can change their aspect ratio as needed to accomplish your goal but you shouldn't have any trouble fitting the remaining armature into a P90 cover once the deleted coil is gone. The magnet(s) are generally glued in place so sawing off the extra width of baseplate shouldn't pose a problem. Start with an undrilled p90 cover in case you need to locate the poles off center.

[jasyr]

thank you for the advice!

[Antigua]

When you split a humbucker, the second, unused coil has a minor amount of interaction with the primary coil that is still active, in both the form of capacitive coupling between the two coils, and a little bit of the magnetic field fluctuation over the unused coil makes its way to the primary coil. Removing the second coil removes those small amounts of "interference", but they're so insignificant that they wouldn't change the overall sound you're trying to retain.

Another thing to consider, if this is in the neck position, is that with all twelve pole pieces / screws in place, the pickup dampens the string to a certain degree, for a given height setting. With only one coil, there will be less pull on the string, which might subtly alter the way the string movement decays. If this is a bridge pickup, the magnetic pull is much less of an issue, regardless.

I suspect what you like the most about the single coil sound is the particular resonance curve you get from the individual coils, and that's not likely to change much if saw the pickup in half.

What might also have a noticeable impact is that, when you place the halved pickup under a P-90 cover, the pole pieces might sit in a different location along the length of the string than where it was when situated in the humbucker configuration, and what you like about the sound might have as much to do with where the pickup is positioned as it does with other properties of the pickup. Assuming these P-90's are going into a different guitar, the guitar in general might be different in such a way that you don't get the same tonal results as you did with the guitar with the Dual Sound in it.

For the ceramic magnet, you'd want it to be in the same place. If you move it somewhere else, it might increase or decrease the flux strength at the strings and alter the sound you get. As mentioned, removing one of the coils already changes this, but reorienting the magnet would change the magnetic profile even further.

[David King]

What he said but furthermore disregard what I said above about changing the aperture because the it's not relevant since you are talking about a single coil in either case and the length of string that gets magnetized might change but I don't think you'll hear that through the one coil.

[Jason Rodgers]

So, basically, you want an underwound P-90 (about 6.8k, or half of a Super Distortion) with one ceramic magnet. That doesn't sound unreasonable.

[jasyr]

Interesting... I've never thought of it that way!

I played a Dual Sound all thru the 80's into the 90's then discovered 'normal' PAF-style & Strat pickups. Eventually favoring the P-90. I really like this into a Rangemaster clone... = instant DS in single-coil mode? hah ha. Cheers j.