Looking to change my Geddy Lee-Jazz Bass wiring from VVT to VPT

Discussion in 'Pickups & Electronics [BG]' started by chuckyboy12001, Aug 14, 2018.

  1. Volume/Volume/Tone

    42.9%
  2. Volume/Pan/Tone

    57.1%
Multiple votes are allowed.
  1. chuckyboy12001

    chuckyboy12001

    Mar 2, 2010
    Looking for advice and any links on how to change my wiring on my Jazz from Volume/Volume/Tone to Pan/Volume/Tone?? I am inexperienced in adjusting electronics but wondered what I should know or if there are any videos, sites I should check out?
     
  2. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    Here's a wiring diagram. The cap is shown in the wrong place, it should connect to the middle tab not the outside.
    JazzBass_1V_1Bld_1T.jpg
     
    Last edited: Aug 14, 2018
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  3. 96tbird

    96tbird PLEASE STAND BY

    Last edited: Aug 14, 2018
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  4. lz4005

    lz4005

    Oct 22, 2013
    One thing you should know is that you'll be running each pickup through two volume pots with VPT, and that will bleed off additional highs and some signal level in a passive system. That's why VVT is normally used with passive wiring. With VVT the signal from each pickup only passes through one volume pot. Depending on how bright and loud a sound you want, it's something to consider.
     
  5. Slater

    Slater Leave that thing alone.

    Apr 17, 2000
    The Great Lakes State
    I don’t care for limiting my tonal options with a blend (pan) control pot. I can get any blend of the two Jazz pickups with two volume pots. Through playing experience, I have acquired the ability to grab both volume knobs at the same time and make my desired adjustments.
     
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  6. 96tbird

    96tbird PLEASE STAND BY

    Works great on mine. Didn't notice loss of highs, just convenience. I think that’s the upshot of leaving the ground wire off the blend pot: you arent dumping signal to ground, rather, using the resistance the other pickup to dim the one being cut indtead of grounding it’s signal.
     
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  7. lz4005

    lz4005

    Oct 22, 2013
    What blend of the two pickups isn't possible with a pan?
     
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  8. SteveCS

    SteveCS

    Nov 19, 2014
    Hampshire, UK
    Anything that involves both being less than 100%
     
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  9. bigtone23

    bigtone23

    Dec 10, 2014
    Denver, CO
    At the end of the day, I prefer a master volume.
    My pickup selection tends to focus on both pickups up full or just the neck pickup. A 3-way switch would work fine, but I wired a bass with the ungrounded 250K m/n pot and really like how it works.
     
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  10. lz4005

    lz4005

    Oct 22, 2013
    You set the ratio between the two with the pan and then the overall volume with the volume.

    You can literally achieve any mix that way. For example, to get the front pickup at 50% and the back at 25%, you roll the pan forward half way and dial back the master by half.

    Math.
     
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  11. Slater

    Slater Leave that thing alone.

    Apr 17, 2000
    The Great Lakes State
    Actually, you can’t have one pickup at 100% and the other at < 100% with a blend pot.
     
  12. SteveCS

    SteveCS

    Nov 19, 2014
    Hampshire, UK
    Actually, with an M/N pot thats all you can do. With an A/C pot, equality is at around 70/70.
     
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  13. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    The math behind it is this:
    in a V/B situation you're using 3 gangs of resistance for volume
    if each one is 500K Ohms & they're all in parallel, that gives you only 167K Ohms of resistance to ground

    in a V/V situation you're using 2 gangs of resistance & the parallel resistance equals 250K Ohms to ground
    one bleeds more signal to ground, & it's not the V/V

    Also, A/C blend pots are the pits!
     
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  14. SteveCS

    SteveCS

    Nov 19, 2014
    Hampshire, UK
    QFT, at least IMHO!
     
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  15. 96tbird

    96tbird PLEASE STAND BY

    So don't ground the Blend pot.
     
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  16. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    If it's not grounded it can't completely silence a pickup.
    In other words you could not truly solo one pickup.
     
  17. 96tbird

    96tbird PLEASE STAND BY

    Yes but you don’t notice it. Walterw also mods his by severing lugs creating no loads which disconnect the dimmed pickup when the pot is at 100% either way solving the issue. Ultimate No-load Ungrounded Blend Pot (Pics!)
     
    ELynx likes this.
  18. That. Did it to replace 3-way pickup switch and don't want anything else for passive. I use master volume knob to silence bass down without reaching to pedal / amp / anything, then tune with clip tuner or find "start position" for a next song (yes I can get that lost on-stage), then dial volume right back. No tone change, no excess movement.
     
  19. Skybone

    Skybone

    Jun 20, 2016
    Scotland
    Why bother with a Pan knob, you already have 2 Volume knobs where you can pan each pickup to your hearts content.

    Leave as is.
     
  20. SteveCS

    SteveCS

    Nov 19, 2014
    Hampshire, UK
    If you actually do the math(s) you will see that it is not as you say...