Charlie Christian Pickup Rattle

[Iced Tea]

Hey,

Just wondering if anyone had any good tips on eliminating rattle on the original style Charlie Christian pickup? I've seen some examples where a small felt washer has been placed in between the screws and the mounting rings on top of the soundboard.

Reason I ask is that I have a Gibson L-50 conversion with one of Colin Cosmini's replica pickups and along with this rattles which can make a few notes sound like they are going through a fuzz box, I also wonder if having a big metal block directly under an older thin soundboard may affect the guitar due to the metal being a very efficient heat conductor, as it heats and cool depending on ambient temperature it could affect playability.

In addition to that, the volume pot is also a bit finicky, I'm not sure what the value is but what happens is that there is basically very little to no output up to about 70% but then all the volume comes in that last 30% so you have to be very careful to make adjustments using the volume control.

One last thing is pickup height, I've tried to set the pickup housing just slightly above the soundboard, about 1.5mm, I felt that having it any higher resulted in the bass strings being too boomy and the overall tone being a bit harsh. Just wondering if anyone had any experience with this? I also wonder if that type pickup has an effect on pulling the strings closer to the fretboard given its size.

Apologies for this slightly rambling post, I've got to say the sound of the guitar is amazing but the idiosyncrasies and quirks of this type of guitar can be quite distracting, any good pointers or advice would be extremely welcome!

[icr]

If you are hearing buzzing, that could indicate the pickup is not installed correctly with all 3 springs. Or, maybe a screw came out, I used Loctite on mine to keep it from coming apart.
I put linear pot on mine, you could try that.
If you play with the tone knob turned down, you could try a different size capacitor. Do you know what capacitor you have in there now?
If it has "Modern" wiring, you could change that to "Vintage", that is with the capacitor on the middle lug of the volume pot.
All parts of the guitar should be the same temperature irrespective on the heat transfer characteristics of the various components.

[Cunamara]

For the rattling, I'd suggest trying some small o-rings between the top and the screws, available in most any hardware store. Cheap, easy experiment. You might even be able to cut them and slide them under without having to remove the screw fully. As with other rattling pickups with springs, the real solution is to replace the springs with surgical rubber tubing. That may have some impact on tone.

For the volume pot taper, I'd suggest trying a vintage taper pot.

As for thermal expansion differences, those are negligible. They'd be ten-thousandths of an inch if that given the narrow range of ambient temperature in which humans can survive.

There is some microscopic pulling of the strings towards the magnet, but it's not visible and is negligible. The magnets in a CC pickup are large but fairly low gauss, so they don't pull that hard. It's an interesting pickup that flies in the face of most common beliefs about pickups: low DC resistance, not a lot of winds, weak magnets and yet pretty hot output.

[Iced Tea]

Thanks to both of you, that's great advice! I'm most likely going to take it to a local tech but it's good to know what kind of troubleshooting to do.

On the question of volume pots and capacitors do you have any good tips on replacements? What the values should be?

[wintermoon]

Barney Kessel had a folded up piece of paper or matchbook jammed under the corner of his, not that I recommend it.