Wiring mess in my 2007 Les Paul & capacitor tone question

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by JohnK24, Feb 18, 2008.

  1. JohnK24

    JohnK24 Supporting Member

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    I got the guitar in Sept, it was from the Guitar of the Week #14 issue. Playing tonight I notice the tone of the neck pup got really dark. The guitar was H90 pickups, double stacked P90s with a push/pull tone knob to tap or untap the coils. I opened the control panel and saw this mess !!!

    [​IMG]

    I noticed a tiny set of twisted wires loose from the terminals on the neck pup tone pot. Using a magnifying glass I saw that there was NO solder on that terminal, apparently the electronics were done around Friday quiting time at the Gibby plant ?:puh:puh Some of the other solder points are thin and suspect too. I'm going to take it to a local Gibson service center for warranty repair.

    I'm also going to see about having them brighten up the tone a bit. In the P90 mod the neck pup just doesn't have the snap of other P90s I've played. There is a capacitor/resistor couple soldered to the terminals of the volume pot, could this be a treble bleed, here's a pic:
    [​IMG]

    ? There is a capacitor on the push/pull tone pots, they are labeled 223, orange, ceramic disc caps. How would you "liven" this guitar up by changing the caps ? I've emailed Gibson for a wiring diagram, but heard nothing
     
  2. cacibi

    cacibi Member

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    So looks to me like - as you said - the tone pots are push-pull for your coil taps using .022 caps for the tone roll-off. Treble bleed networks on both your volume pots.

    By changing the cap value on the tone pots - you change the frequency roll-off characteristics. A higher value will get darker as you turn the knob - and a lower value will have a less drastic effect. Try .05 if you want the knobs to go darker and .01 if you want them to be less dark/have less effect on the overall tone.

    I'm not a Gibby guy - so, I don't know what pot values are standard to use with P-90's, 250 or 500k; but changing the pot value will affect the high end. 250k pots are used with teles to tame the brightness whereas 500k pots are usually used with humbuckers so they don't get too dark. So - as you can see, increase the pot value if you want a brighter tone. Some tele freaks will even use 1meg pots for ultra treble!!! Craziness!!!! But may not be too outlandish to help a really dark pickup.
     
  3. JohnK24

    JohnK24 Supporting Member

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    Well, after a little web surfin' I found a good push/pull coil tap diagram and using my needle nose plyers and a forehead LED spot lamp I was able to re-solder the wire. She sounds better now too.

    J
     
  4. skylabfilmpop

    skylabfilmpop Silver Supporting Member

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    John since you are handy with a soldering Iron.....Try removing the treble bleed circuit (the 103 cap and resistor on the volume pots) and relocating the brown wire that links the tone and volume pots to the center lug of the volume pot. In the current configuration the tone cap shunts a little treble to ground even when on 10, making a few adjustments will give you more high end all around and still maintain highs as you roll yur volume up and down. It may be less work to replace the volume pots all together, and for the few bucks some new pots (rs superpots or others) might cost there will be a bit of tonal improvement as well. BTW its not a mess. It actually looks pretty neat considering all the extra solder points and wire a coil tapped pickup requires. It could be cleaner if the coil taps were n the volume pots, but I think that would be a hassel to use without inadvertently bumping the knob.
     
  5. JohnK24

    JohnK24 Supporting Member

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    Thanks for the advice and information. For now I'm happy the original coils tapping is working. I plan to replace all the pots/caps in the future when I put Lollar's "Sean Costello" wind P90s in the guitar.
     

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