Conference napalm::guitar

    Rich
    
      The switch was probably added for the purpose of coil switching as
      you stated. Since the hole and switch is there you might as well
      make it functional. I have a "69" LP standard maple top that I
      had considered doing the same thing to. But due to the age and
      condition of the guitar I was advised not to by just about every
      one I talked to. They felt it would devaluate the resale value
      cosiderably. But' as you stated I thought it a inexpensive way
      of getting two sounds from one guitar (Gibson/Fender) type sounds.
      I did not do it and have since bought a Fender strat and tele.
      But' if my guitar had already been altered such as yours I would
      have made the switch a coil cutter. 
      Just about any service person could do this for you. And the work
      would not be expensive. I have had very good work done on my guitar
      from Wurlitzers in Boston. They are located near Berkley 180 Mass.Ave
      (617)738-7001. I know someone out there is going to come back with
      a THEIR BUTCHERS reply. But I have always had good luck with them.
      By the way they were the one's that finally convinced me not to add
      the switch to mine. The guy said he could do it, but even though it
      meant lost work to him he recomended I not alter my guitar.
       Good Luck
         Bob
    

    When replacement pickups starting getting popular in the mid seventies
    "coil taps" were all the rage.  They came in two flavors:
    
    1. Simply turn off one coil of the humbucker to get a single coil
    sound, but lose hum rejection.
    
    2. Have a tap partway down the winding of the pickup.  This retains hum
    rejection, but since there is a smaller number of turns of wire, the
    sound is brighter, although of lower volume.  This setup is preferable
    as it is less noisy.
    
    In either case, the pickup will have four (or more) leads coming from it
    if it is designed for coil tapping.  The DiMarzio Dual Sound Humbucker
    is such a pickup.
    
     						Brian
    

    Re: .1
    
    One way to add a switch without defacing your guitar is to use
    push-pull pots.  You can always hang onto the stock pots if you're
    concerned about being able to "restore" the guitar in the future.
    
    							Brian

    Rich,
    
    It should be pretty easy to hook up.  Dimarzio includes switch wiring
    configurations with thier pickups.  The basic idea is that you can
    either wire it so that the switch kills the output from one of the
    coils in the pickup, changes the phase between the coils, makes them in
    series or in parallel, there's a buncha options.  
    
    I'm not very knowledgable on electronics myself, so I don't really
    remember how you connect the switch for each of those combinations, but
    you might call up Dimarzio, I bet they'd send you one of the pamplets
    that comes with the pickups.  The instructions they give are very
    clear, even for someone with no electronics background. 
    
    Bob,
    
    If you wanted switches but didn't want to drill a hole in your guitar
    (I wouldn't), you could replace one (or both) of the tone (or volume)
    control pots with a pull-switch pot.  Easy and reversable with no
    changes outside of the guitar.
    
    Greg
                                                            

    Woop...notes collision...

    
     All,
    
     Wow, thanks for all the great information. One thought. Since the
     Dimarzio is already pre-wired, it might make sense to just wire that
     one up and see what it sounds like. The Dimarzio is the "treble" PU (that
     is the bridge PU, right?), giving that one more of a STRAT sound while
     leaving the other original "Rhythm" PU alone, might make for an
     interesing sound effect, yes?. 
    
     Any other tidbits would be appreciated. BTW, I would NEVER have
     drilled a hole in this thing. It's an otherwise gorgeous natural maple
     top Custom. Oh well, since it's there.......
    
     Thanks again,
    
     Rich 
                                  

 I made a better modif. on my LP. I hate Push-Pull pots, you never know in which
 position you are and their position can change when you pick a wild chord....

 I used the tone pot (who use it anymore !??!) to provide an 'analog' switch from
 Humbucker to Single coil sound. See the following drawing.

     P.U.
   ---+---
   |  |  |
   |  |  |
   |  |  |
   |  |  |
   |  |  |
   ---+---
   |  |  |
   |  |  ----------------------------------- to Volume Pot.
   |  --------------------------------
   |                                 |
 -----                               \
 /////                               /<- Tone Pot (stock 250k)
                                     \ |
                                     / |
                                     |-
                                     |
                                     = 10nF cap
                                     |
                                   -----
                                   /////

 It sounds really great !. It also provide unusual sounds when the Humbucker/SIngleCoil
 pot is in middle position. It is a mix between Humbucking/SingleCoil sound.

 The other advantage is that the 10nF cap makes a Low pass filter. The bass response of
 the 'grounded' pickup is kept, giving a softer/wramer sound in SingleCoil position. 
 
 I use Seymour APH1 (Alnico Pro) pickups and my Lespaul sounds amazing with infinite
 sounds possibilities. I also own a Strat but the singlecoil sound is MUCH better
 (no hum..) on the LP.

 More, this modification can be done without new hole in your guitar, only
 electric modif..

 Regards
 J.P.

    Re: .7
    
    That wiring setup is similar to a patented circuit Peavey used on their
    T-series guitars and basses.  It was dropped in later models, but had
    the advantage of giving you continuous adjustment from the "woman
    tone" to a cutting full-on single coil sound with no switches.
    
    							Hartley
    

    re: .7
    
    J.P. (or anyone),
    
    I know next to nothing about electronics, but I do know which end of a
    soldering iron to hold, so I thought I'd try your mod on my SG.  But
    tell me, what is "10 nF" expressed in uF (microfarads)?  I'm thinking a 
    nF is a nanofarad, which would make it .001 uF, so 10 nF would be .01 uF.
    Is that right?
    
    Also, don't capacitors have a "+" and a "-" side?  Which side goes to
    ground in your diagram, or doesn't it matter?  Thanks.
    
    Tom Not-so-swift

 re:-1

 1) The right end of a soldering iron is the COLD one.....

 2) 10nF is 10 nanofarad = .010uF (you win !)

 3) This cap has no polarity. Buy a .01uF/63V plastic dielectric cap
    (avoid ceramic, they sound like b*llsh*t to me...).

 Hope you will enjoy this mod. Believe me, it sounds great !!!!


 Regards
 J.P.

    re: .-1
    
    Thanks!  Now if I only knew which end of a guitar to hold...
    
    Dave

    J.P.,

       OK, I took the cover plate off the back last night, and the tone pot
    says "500K" on it, not 250K.  Does this mean I need a different value 
    cap, or will this just give me more (or less) flexibility?

    Also, the wire comes from the pickup to the volume pot, then one wire
    goes to the tone pot.  The tone pot already has a cap wired as in 
    your diagram, but its value is unmarked; it's unlikely to be .01 uF, 
    right?  If the wiring is as I've drawn below, do I just replace the
    cap with a .01 uF one?

    Sorry about the dumb questions; someday I have to learn to read 
    schematics.

    Gunga Dim


    Wiring for one pickup (from memory - pot terminals may be mixed up):

        ----------       volume          tone
        | pickup |      /\/\/\/\       /\/\/\/\   <- both 500K
        ----------      |   |  |       |  |   |
          |    |        o   o  o       o  o   o
        -----  +--------(---+  |          |   |
        /////           |    -----        |  ===  <- unmarked cap
                        |    /////        |   |
                        |                 |   |
              jack      +-----------------+ -----
          | +-------/\  |                   /////
          | |           |
          | o-----------+
          o
          |
        -----
        /////

 There is a problem, and a major one !
 If you look at my first drawing, you will see that the tone pot+cap 
 are connected to the TAP point of the humbucker....

 In your description, there is no TAP connexion coming from the pickup.
 This is a 'classic' Gibson electronic.
 The tone pot is connected to the Hot point
 of the volume pot. This is a simple tone control but no Single Coil/Humbucker
 control...

 You have to modify you pickup itself before. You will have a problem because
 many of the stock SG pickup are filled with epoxy, with NO WAY to extract a 
 TAP wire...
 
 You have to change the stock pickup for a 4 wires cable one or modify the stock one.
 I already did it on a 2 wires Seymour SH1 (The 59'). You have to change the
 shielded cable to a 2 wires + shield one. Connect shield to the pickup case and
 the cold point, connect 1 wire to the 'central' point of the pickup (where the 2
 pickup's wires are soldered together), and one wire to the Hot point.
 Take care of the windings !

 Hope you understood my description (Please be lenient to my english...)

 J.P.

 P.S.: The 500K pot doesn't matter and the stock cap value is generally 0.020uF.

    J.P.,
    
       I see, your modification doesn't just filter out some frequencies -
    it actually does change the pickups' output from humbucker to single
    coil.  Hmmm...  Maybe that's what Brian was saying a few replies back.
    
       Well, I guess I shouldn't be surprised that I don't have the right
    pickups; my SG is an Epiphone copy, and who knows what sort of 
    humbuckers it has?  I may poke around inside the pickup mounting rings 
    to see if there's an extra wire in there, but it sounds as if, as you 
    say, I have to replace the pickups with more modern ones to do this 
    modification.  %^(
    
       So I think I'll just stick with the stock setup.  New pickups would
    cost a significant fraction of what I paid for the whole guitar, so
    I'll probably wait until I buy a "real" Gibson before I do that.
    
       And don't worry - your English is far better than my electronics.
    Thanks for your help.
                                                                          
       Dave

    My experience with those Epi gibbo copies is that the pickups they put
    in 'em suck anyway.  You're probably better off getting a nice SD or
    Dimarzio with 4 wires to replace it.
    
    Greg

    re: Greg
    
    Well, I bought the thing because I like the way it sounds (you know,
    when someone else plays it), so I guess that means I like the pickups.
    They look a little crude, with no covers and all, but they sound like
    humbuckers to my untrained ear.  What should I be hearing that I'm not?
    
    Just curious.  And of course, if I can improve the thing a lot by 
    replacing the pickups I'll certainly consider it.  Thanks.
    
    Dave

    Dave,
    
    Don't let us talk you out of something you like!!!  If they sound good
    to your ears, then they're right for you.  I didn't like the ones I
    heard, I thought they were thinner sounding and "clankier" then other
    humbuckers.  No biggie, everyone has different tastes in what's good.
    
    Also remember that some pickups sound different with different amps. 
    For instance, I'd put a Dimarzio MegaDrive into one of my guitars a
    long time ago and it always sounded harsh to me though most of my amps
    until I got my Marshall and it really sounds great through there.
    
    Greg
    
    

    One question, how do the pickups cut through in band situations?
    The thing I've often found in the hummers on Gibson clones is that
    they sound ok in your bedroom but don't cut through as well with
    other instruments around.  If you like the sound AND they cut, then
    stay with em.

    re: Greg
    
    Well, they sound good to me right now, so I'll keep them until I think
    otherwise.  One nice thing about this axe is that I don't have worry
    about keeping it stock, or unscratched, or even unstolen, 'cuz it's not
    worth much except as a "player".  And it plays better than *I* do right
    now.  %^)
    
    As far as amps go, I've been playing it mostly through a headphone amp,
    once in a while through this 4-tube Rex practice amp (a refugee from
    the 1950's), and very occasionally through this bastardized twin a
    friend loaned me - actually a beat-up silverface Quad Reverb with two 
    speakers removed; I call it the Quadraplegic.  The guitar sounds best
    through the Quad, but my mistakes are more obvious and it's real
    discouraging, so I usually stick to the Rex.
    
    So I'm not at the point where I can accurately isolate the pickups'
    contribution to my, uh, unique sound.  Maybe I can convince my wife
    I need a Marshall, waddya think?

    re: Rick
    
    Uh, "band situations"?  Well, thanks for the assumption of competence,
    but I've only been playing guitar since September, and the issue of
    band situations hasn't come up yet.  If you know what I mean.  So far
    my hummers (the Gibson clone ones) don't even sound good in the
    bedroom.  But I'll try to remember to see how they cut through the mix
    when I finally play with someone (you know, in the nursing home).
    
    Dave
    

    Quadrplegic...haha!!    
    
>    So I'm not at the point where I can accurately isolate the pickups'
>    contribution to my, uh, unique sound.  Maybe I can convince my wife
>    I need a Marshall, waddya think?
    
    Clearly you do, I'm convinced...
                           
    Greg

>    Clearly you do, I'm convinced...
    
    Thanks, Greg, I'll tell her you agree with me.  %^)
    
    Dave

    I'm certain that'll take care of it, dude.  You might as well just go
    buy one on the way home, it's a sure thing!
    
    Greg

    Geez, don't even say that...  Just this morning we closed on a home
    improvement loan, and I've got this checkbook...
    
    Dave

    Having a Marshall at my place definitely improved my home!

    My Marshall is a handy dandy about house multi use combo.Only last
    night after having a wee jam in the house I sat down with a coffee and 
    rested my cup on it............voila,a coffee table!And,earlier this
    year I decorated my house and the Marshall was used again.I couldn't
    reach the top of the wall so I got out my Marshall............voila,a 
    step ladder!
       Won't you be surpirsed when the guy's come to work on your house and
    they have a big stack o' Marshalls to aid them in their construction??
    
    
                                                  staynz
    
    
    ps........I'm bored!