Cure for wildly imbalanced hums on Burny LP

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by MikeMcK, Jul 26, 2008.

  1. MikeMcK

    MikeMcK Member

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    A couple of months ago I bought a Burny LP from a member here. Love the guitar, but the neck pup seems excessively dark. Of course, if I tweak the amp's settings to compensate, the bridge pickup becomes extra bright.

    It's been a long time since I had an LP-style guitar, but I don't remember that much of a tonal gap. Is this characteristic of Japanese LPs? Any known cure before I start randomly buying caps and pickups? Thanks
     
  2. mike80

    mike80 Member

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    You could try putting lower value pots on the neck pickup. That should let more highs come through.
     
  3. Tone_Terrific

    Tone_Terrific Member

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    Try higher value pots on the neck pup and install a treble byapss cap on the neck vol pot. Try the cap first--easier
     
  4. Dana Olsen

    Dana Olsen Gold Supporting Member

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    Hey MikeMcK -

    Here's a trick: try using an alligator clip to jump from the pickup's output direct to the output jack - completely bypass the vol and tone pot (you don't have to unsolder anything - just clip around the pots).

    If the tone gets noticeably brighter, you can fix it by changing the pot values as mentioned above for the neck pickup. If they're 300K pots, try 500K. If 500K, try 1 meg (1,000K).

    Unsolder and measure the existing pots - see if they actually read the same value as the label says. Don Mare and I found pots labelled 250K that measured out at 220K and 170K - we were wondering why my Tele sounded so dark, and THAT was why.

    If there's no change when jumping direct to the output jack, it's the pickups that sound that way, so you're looking then at replacing them.

    Hope this helps, Dana O.
     
    Last edited: Jul 26, 2008
  5. MikeMcK

    MikeMcK Member

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    Thanks for all the suggestions...
     
  6. mike80

    mike80 Member

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    Oops. :eek: My apologies. I meant higher value pots.

    Thanks for correcting that TT.
     
  7. walterw

    walterw Gold Supporting Member

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    try measuring the dc resistance of each pickup. if (as i suspect) the neck has more wire wound on it than the bridge, then playing around with pots and resistors isn't going to cut it. the thing to do is pull the pickups out and swap them around, so the hotter pickup is in the bridge where it belongs.

    also, adjust your bridge pickup right up close to the strings, then adjust the neck pickup down until it's about the same output as the bridge (use a clean amp sound to determine the balance).
     
  8. thorny64

    thorny64 Supporting Member

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    You can measure the value of the volume pots by checking them with a multimeter set to the right ohm setting and touching the two outer posts on the pot. Similar to what olson said in the previos post, I had a guitar that sounded VERY DEAD. It was a high dollar guitar too, US made, and I measured the pots and they were 50K instead of 500K. It had the wrong pots in there from the factory.

    I had already put two sets of pickups in there before I realized this! :NUTS

    Just don't assume that it is ok, check it! I agree with Walter. Measure the resistance of your pickups. I would expect you would see something around 8K if you are talking a traditional PAF type pickup. If one is wildly off from that it may have been changed or may have a problem with it. I have had pickups that had inner coil problems and would read really high resistance and still work, but sound really muddy. If it is messed up like that you can have it rewound or replaced.

    How close to the strings do you have the pickups set too - that makes a difference. If a neck pickup is similar in resistance to the bridge but is much louder, you can sometimes back the pickup off from the strings a bit to clean it up and lower the output. If it is dark, you can tilt the treble side a little closer to the strings to help balance it (or angle the bass away from the strings more).
     

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