1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
     
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

Harmony P/MM frankenbass "build"

Discussion in 'Luthier's Corner' started by tdogg, Apr 8, 2009.


  1. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    *mods; if this should be in a different column, please move it. thanks!

    ok so here it is, i have an old harmony p-bass that my mom found at a garage sale for ike $10. it plays great but the elctronics are in horrible shape. i realized that i have the spare parts laying around to really hot rod this thing so here goes. heres some pics of the bass as is:
    100_1928.
    100_1929.
    100_1931.
    100_1936.
    100_1933.

    *question... does anyone know if this is some rare antiquity that i shouldnt be messing with? i doubt it but you never know.

    heres some pics of the disassembly:
    100_1942.
    100_1946.
    100_1948.

    heres the plan:
    -route a hole for a MM pickup
    -clean the electrical tape gunk off the body (what should i use?)
    -sheild the cavities
    -install 2 band active eq that i took out of an old yamaha BBG5S
    -install Bartolini MMC (yes i actually hadd one of these in the toolbox. it was for another project but i like this one better)
    -install series/ parallel switch for the MMC pup
    -install a resistor inline with the MMC to balance the output of the pickups. (is this necessary? what size resistor should i use?)
    -play it really loud!:bassist:

    im thinking this will be my new rock-out-with-my-(rooster)-out bass.
    suggestions are welcome (i already thought about a trem... but i dont have the cash right now:()
     
  2. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    oh and i forgot... im going to install a momentary cut-off switch also
     
  3. LCW

    LCW Banned

    Mar 2, 2009
    OREGON!
    dude i wanted to do that to my old ion p bass , but i plan on using 2 stingray pick ups

    sweet!
     
  4. Are you going to install the MM pup between the P pickup and the bridge or, are you eliminating the Precision pup?
     
  5. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    im planning on installing it in between the p pickup and the bridge. i know it wont be the perfect "musicman sweetspot" but i think it will sound good. thats why i was curious if this bass is worth anything, but i highly doubt it. so by tommorow i should have the routing done and i'll take some more pics. the only thing i had to buy for this was some pickguard screws, sheilding tape and knobs.
     
  6. are you routing yourself? very interested - want to do this at some point.

    Want to see how close you get it to the P!
     
  7. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    yeah im routing it myself, but i have had some practice at this and have the right tools. if you want to do this yourself, definitely practice on some scrapwood first!!!!!
     
  8. LCW

    LCW Banned

    Mar 2, 2009
    OREGON!
    Take lots of pics !:)
     
  9. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    o i will, could anyone let me know if i need to put a resistor inline with the MM pickup to equal the out put of the old p-pickup? or will the blend knob take care of this?
     
  10. wd-40 or goo-gone/goof-off will get the tape residue off.

    where are all these switches and knobs going? 2 or 3 volumes, 2 band pre, series/parallel switch, and a kill switch. thats a lot of stuff for a p bass.. especially if you're trying to fit it all on the PG.. unless you're going to route to move them further up the body. even in concentric/blend/push-pull pot calculations, thats a LOT of ****, and a LOT of wires.
     
  11. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    yeah its going to be tight. someone did a little extra routing before me (im assuming this because the cavity was pretty ugly and hacked up) so i cleaned that up and made some extra room for the battery. i have a 2 band eq with 1 volume and 1 blend. i'll see how that fits before i add the other stuff. and im not worried about drilling holes in the PG, it already has been broken and glued together so im sure ill replace it eventually.
     
  12. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    100_1951.
    centerline drawn and pickup traced
    100_1953.
    hole routed and ready to drill hole for the pickup lead
    100_1954.
    checking for alignment
    100_1956.
    battery pocket added

    well now all the routing is done (i hope) and ill sheild it today, and then wait for UPS to bring my pickup screws and pickguard screws
     
  13. vbasscustom

    vbasscustom

    Sep 8, 2008
    well done, thats lookin good.
     
  14. LCW

    LCW Banned

    Mar 2, 2009
    OREGON!
    Nice routing job!
     
  15. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    heres some updates. i finished sheilding the bass and wiring in the pre-amp. wiring was really tricky because i didnt label ANYTHING when i tore the pre-amp out of the previous bass. but i did get it figured out and put on 1 string just to make sure that it made sound. then i realized that my series/parelell switch wasnt working. the MM pup was fine in paralell mode but didnt make any sound in series mode. i had another switch of another brand so i wired that in, same result. so i wired the pickup in series, straight to the jack, no sound. so i pulled the pickup out to switch it with another bart MM pup i have in another bass, and realized that a wire on the back of the pickup itself was loose. so i resoldered that and commenced stuffing all the electronics into the cavity. the wiring was tight, and probably would have fit, if the circut board attached to the treble pot wasnt 3/16" too loong to fit in the cavity. :bawl: the cavity just isnt deep enough for this preamp. so now the bass is MM -> DPDT switch -> jack. and it will stay this way for now.
    100_1965.
    beleive it or not, it was going to fit untill that stupid circuit board bottomed out. and yeah i did decide to leave out the momentary cutoff switch.
    100_1972.
    100_1978.
    so the bass is playable, but i dont quite have the tonal diversity that i was aiming for. if anyone has a suggestion on an electronics setup that will fit in here (besides the standard P-bass setup) please let me know. ill have to keep my eye on the evil-bay
     
  16. stevetx19

    stevetx19

    Sep 28, 2006
    Denton, Texas
    can you try routing the control cavity a bit deeper where the circuit board is?
     
  17. tdogg

    tdogg

    Jan 17, 2001
    Brooklyn Park, MN
    i thought about that, but its kinda thin already. im gonna get a caliper and do some careful measuring before i do that. my other thought is to go passive as it originaly was. does anyone know where i can get a wiring diagram for: blend-volume-1 or 2 band eq (passive) ?
     

Share This Page