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Jazz Bass wiring - V + T + T

Discussion in 'Pickups & Electronics [BG]' started by braud357, Dec 25, 2012.

  1. braud357


    Jul 1, 2010
    Gonzales, LA
    I am helping a friend modify his Jazz bass, and he is wondering if you can wire a Jazz bass with a master volume and individual tone controls for each pickup. Do any of you know where I can get a wiring diagram to do this ?? -- THANKS !
  2. Yes and no.
    Tone controls run parallel to the signal path, which means that they work as masters. There are two ways around this. One is to run resistors in series with each pickup so that the pickups will not be directly parallel. This will kill output, however. The other way is to actively buffer the signal paths. This will change the way the pickups behave when mixed, as they will no longer load against each other, and instead see a constant input impedance from the buffer.
  3. Stealth

    Stealth Supporting Member

    Feb 5, 2008
    Zagreb, Croatia
    Here you go. Instead of the drawn blend pot, just join the "red" and "blue" together towards the volume pot. The resistors between the tone and volume pots are mandatory, they provide isolation between the tone controls so each only affects its own pickup. You can use any value from 94 to 220 kΩ for the tone pots - the higher the value, the better the isolation - but you'll have to turn up the gain on the amplifier a bit as the bass will be somewhat quieter because of those same resistors.


    Edit: curse you, line6man, for beating me to it. :p
  4. braud357


    Jul 1, 2010
    Gonzales, LA
    Thanks fellows !!
  5. Sponsored by:

  6. Waste of time. You'll see.
  7. Ric5

    Ric5 Supporting Member

    Jan 29, 2008
    Either go with stacked pots or go active.
  8. FrenchBassQC

    FrenchBassQC Supporting Member

    Jul 13, 2011
    Gatineau QC CA
    I agree with you, I don't see the value of doing this... :meh:
  9. +2. Pretty much useless.
  10. countbassiedad


    Apr 29, 2010
    No affiliations
    I've been wondering this too. I have considered doing tone switches using a push pull on multiple pickup basses (one volume per pickup with pull for high cut).

    Never pursued it because it seems logical to me that any line from hot to ground would affect all pickups.

    But I do wonder how they do it on a Strat guitar (most have VTT).
  11. They don't. There is a switch for pickup selection, but if you select neck and middle, both tone controls do the same thing, and even share the same capacitor.
  12. walterw

    walterw Supportive Fender Gold Supporting Member

    Feb 20, 2009

    a routine mod for strats is to move the second tone to hit the bridge pickup instead of the middle, both to avoid doubling up on the neck+middle settings and to tame a bright bridge pickup.
  13. walterw

    walterw Supportive Fender Gold Supporting Member

    Feb 20, 2009
    now you could wire these pickups in series (yielding a very different tone, much louder and bassier) and then wire a tone to each pickup.

    at that point, the tones would be independent, and would also give you a neat side effect: by turning one tone off, the two pickups would still add their low end together for the series bass boost, but you'd only have the high end of the other pickup. single coil high end and humbucker low end at the same time!

    it sounds like one pickup, but with a big bass boost.
  14. braud357


    Jul 1, 2010
    Gonzales, LA
    Some of you must have misunderstood my question - I was asking if it could be done - not for opinions as to the value of doing so --- JEEZ !! I had told him that installing stacked pots would probably be his best option.
  15. JTE

    JTE Supporting Member

    Mar 12, 2008
    Central Illinois, USA
    On a Strat, one of the controls is wired to the output of the switch for the neck PUP, and the other to the midlle. Because the switch takes the other PUPs out of the circuit, they don't interact- until you set the switch to select two pickups. Even though there's no tone control on the bridge PUP, if you select M/B the tone control cuts the highs on BOTH pickups.

  16. Stealth

    Stealth Supporting Member

    Feb 5, 2008
    Zagreb, Croatia
    I hadn't tried that one, yet. How would that be different from having a single tone pot with half the resistance and a cap with twice the capacity?
  17. How so? I answered your question.

    That being said, it would be wise to consider the conventional wisdom when considering unorthodox options. Weigh the advantages against the compromises and decide accordingly.
  18. walterw

    walterw Supportive Fender Gold Supporting Member

    Feb 20, 2009

    utterly different!

    a lower-value pot and a higher-value cap just means more loss of highs, even with the tone on "10". not even remotely like series-wiring.
  19. Stealth

    Stealth Supporting Member

    Feb 5, 2008
    Zagreb, Croatia
    I'm sorry, I should've specified - I know the series/parallel modes are vastly different. My question should've been "in series mode with the layout pickup-tone-pickup-tone-volume-jack, wouldn't you essentially have both tone pots and caps in parallel to the entire circuit thereby getting the effect of half a pot and twice the cap?"

    Also, what would provide isolation for the two adjacent pickups so each tone control would only be affected by its own pickup? Would the tones be wired like volume pots (as voltage dividers) with the cap on the grounding lug to provide isolation?
  20. willbassyeah


    Oct 9, 2011
    The only time when using a filter as preamp is to run it active like wal, alembic or
  21. braud357


    Jul 1, 2010
    Gonzales, LA
    Thanks for the information and comments - he has decided to leave it "standard"

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