Push/pull options in Les Paul

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by shakti, Feb 20, 2006.


  1. shakti

    shakti Member

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    A little over a year ago I got an RS Guitarworks Premium upgrade set for my '82 LP Standard. It made a huge difference - much fuller and livelier sound with a useable range throughout the pot's travel.

    Anyhow, at the time they didn't offer a push/pull pot with themlong shaft needed for standard production Les Pauls, but they have one now. At the time I put in new PUs (High Order A2), but ordered them standard with two leads each.

    I am wondering if I can use any push/pull functions with these PUs. Obviously I can't split the coils, but that's not much of a priority...but can I somehow do any kind of phase in/out switching? I am about to order an upgrade set for a Strat, and would want to order the push/pull pot at the same time, but only if I can actually do anything useful with it, with those standard two-lead PUs.
     
  2. shakti

    shakti Member

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    bump...anyone in the know?
     
  3. Jim Collins

    Jim Collins Member

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    There isn't much you can do, unless you modify the pickups. You either have to provide an extension to the center join (where the two coils in the humbucker are joined), or provide a seperate ground for the coils and base. Without either of those, a push/pull option isn't going to do anything for you, unless you want to do something like eliminate the tone pot when pulled.
     
  4. shakti

    shakti Member

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    Thanks,

    I'll leave it for now then!
     
  5. Clorenzo

    Clorenzo Member

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    You can use it to connect the pu's in series. It gives a hot and thick tone that, depending on your style/amp/taste/etc., may be interesting. I have it in my Warmoth LP-cloner and use it for a very nice, warm, jazzy tone. Here's a great example courtesy of Harry Jacobson (scroll down to "Neck/Bridge combos"): http://www.harryj.net/audio_clips_of_usacg_tele.htm
     
  6. Jim Collins

    Jim Collins Member

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    He's still going to have to modify at least one of his pickups to put them in series. I believe each of the pickups feature the vintage style shielded lead.
     
  7. Clorenzo

    Clorenzo Member

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    You are right Jim. Sorry Shakti, my mistake!
     
  8. John Phillips

    John Phillips Member

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    One thing you can do is to put a cap in parallel with a resistor, in series with the pickup, before the volume control - this gives almost a pseudo 'single coil' tone - brighter and quieter.

    I did this once, and it did work quite well, but I can't remember the values. Clorenzo might know - or at least be able to work it out! :) From vague memory it's something like a resistor of the same value as the pot, with a .001uF cap in parallel. This should give about half the volume and much brighter (sort-of like a single coil) but still hum cancelling since it's really the same pickup.
     
  9. Clorenzo

    Clorenzo Member

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    Thanks John, perfect excuse for a break from work! ;)

    I've tried several combinations and the one that works best is a 220k resistor and a 180 pF cap. This is the response of a typical PAF (500k pots, 500pF cable capacitance, 1M amp input impedance):

    [​IMG]

    This is the modified response (180pF cap + 220k resistor):

    [​IMG]

    For comparison, this is the response of a typical single coil pu with 250k pots:

    [​IMG]

    Almost dead on! The drop in level would be roughly equivalent to turning the volume down to 7.5-8 or so.

    This one definitely goes in my mods-to-try list!
     
  10. Rock Johnson

    Rock Johnson Member

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  11. tjs

    tjs Senior Member

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    If you try this, would you mind posting clips of the pickup with this mod and in the standard split mode? It would be very interesting to hear the difference. (I'd do it if I had the wiring skills, but unfortunately I don't).
     
  12. shakti

    shakti Member

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    Hmmm..interesting! Please do post clips if you actually do this! I'll leave it on the backburner for now. First thing I'm gonna do is remove the cap and resistors on the neck volume control. This was the premium RS Guitarworks set, which had an additional twist to preserve treble when turning down the neck volume. It works great with a clean amp, but for overdriven amps I thought it sounded a little artificial, and actually made it even harder to get the amp to clean up...

    I have some ideas for the guitar in question - I'm a huge fan of John McLaughlin (hence my screen name), and I'm toying with the thought of turning this LP into a scalloped one like he used in the late 70s (not LP though). Would be cool to have some switching options like on his fabled Double Rainbow doubleneck which he used from 73-75...
     

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