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Magnetic pickups and license plate conflict? Advice needed.

I have arrived at the electrics stage of my second CBG build, a 4 string license plate guitar.

I want to keep the front of the plate as clean as possible. I have neck and bridge pickups, two P90's. I would ideally like to mount them under the plate and run the screws up though the plate (though some rubber grommets). Will the screws going up through the steel license plate or the pick ups being right under the plate cause me problems with distortion or interference? If so is there any kind of shielding I can use to isolate them?

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Permalink Reply by Dan Sleep on July 22, 2013 at 11:44am

You can also just put the mag pup up to the underside of the license plate, and if the strings are close enough, the pickup will still work because there will be a magnetic field for the strings to interact with. Try it out!

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Permalink Reply by Piht Bull (Delta Dawg Guitars) on July 22, 2013 at 11:56am

Dan you just got my head spinning . i wonder how much magnetic field is too much ?

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Permalink Reply by Dan Sleep on July 22, 2013 at 12:01pm

Only one way to find out!

I would just take a license plate and stick a wired up pup to the bottom of it, then hold it next to an existing guitar with electric strings on it and see how it goes.

As far as too much, you want the strings to be close enough to the magnet, yet not so close that the pull of the magnets dampens the vibrations of the strings.

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Permalink Reply by Piht Bull (Delta Dawg Guitars) on July 22, 2013 at 12:10pm

wonder if you could turn the plate itself into a pup . ive never done any magnetic reserch but im on a mission now ,

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Permalink Reply by Randy S. Bretz on July 22, 2013 at 1:00pm

That's what happened when I mounted the pup against the washboard metal, the whole thing became active....lol, You can see the 2 screws holding it place in front of the bridge. The metal on the washboard is galvanize. So the high spots on it are like pickups...a lot of them...lol

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Permalink Reply by Piht Bull (Delta Dawg Guitars) on July 22, 2013 at 1:37pm

lol thats awesome !

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Permalink Reply by The Phrygian Kid on July 22, 2013 at 6:35pm

This does work great altho you don't 'pick up' the strings singing so much as you'll 'pick up' the licence plate itself singing. Which is great.

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Permalink Reply by Ron "Oily" Sprague on July 22, 2013 at 12:33pm

Tom,

Take your P90s, and see if they stick to your license plate (if the plate is steel, they should). Now, your plate should be within the overall magnetic field generated by the magnets imbedded in the two pups, and will itself have become temporarily weakly magnetized. Connect your pup wiring to a jack, plug into an amp, and string up your guit (temporarily). See if you get any amplification. If you do, forget about the screws and rubber grommets.

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Permalink Reply by The Phrygian Kid on July 22, 2013 at 6:33pm

Yes this works great I've been doing it for years on cookie tins ;)

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Permalink Reply by Tom Lauten on July 22, 2013 at 7:57pm

Wow...ok, thanks guys! I guess I have a lot of experimenting to do. I'm hoping that if the whole plate become active I can still get the benefit of both a bridge and neck pup placement in terms of sound. I also hope I don't create a pup so large that it picks up every stray bit of EM noise like transformers and fluorescent lights!! Only one way to find out. I,will you all know. Thanks again!

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Permalink Reply by The Phrygian Kid on July 22, 2013 at 9:13pm

Make sure you earth the licence plate. Put a layer or two of tape over the pole pieces before you snap the pickup on. Because I do this on cookie tins it's entirely shielded ie silent. With what you're doing you'll have that only on one surface but it'll still certainly help. It wouldn't be too difficult to extend the shielding entirely around the pup using foil or copper tape, just take care not to short out the hot side of the coil. ( Tape again..) Have fun, it's a great sound grab a delay pedal and try drumming on it ;)