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Wire Jazz & P Bass Pups for Volume only?

Discussion in 'Pickups & Electronics [BG]' started by bizzaro, Jul 31, 2002.


  1. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    I am hot rodding a P bass. I will add a Jazz pup in the bridge position. Can I use the tone pot as a Volume knop for the Jazz pup? My plan is to not have any tone controll other than the volume of each pickup/set? Will This work? Recommended??? I have read that when you lower the tone on passive pots it is really just taking out the higher frequencies or something relative to that. Also what is the recomended placement of the jazz bridge pup in a P Bass:confused:
    Thanks
     
  2. There is absolutely no reason why your bass wouldn't work without a tone control.
    I have even heard that it would sound better in a passive system. (because of the frequency cutting you mentioned)
    Anyway, most manufacturers normally use the same pots for the volume and tone control (the tone control will have a capacitor attached), if this is the case with your bass, then I don't see a problem. (you can always replace the pots when you're not sure)
    Check out the Gearhead site, click the guitar/bass schematics and wiring diagrams link. (I think the Stu Hamm bass has both P and J PU's)
    http://www.mrgearhead.net/
    And while you're working on your bass, I would shield it too (if you haven't done that already), it makes a huge difference ! (no more noise or hum)
    Check out the guitarnuts site, you'll find everything you need to know about shielding, it also has an article on volume and tone controls.
    http://www.guitarnuts.com/wiring/menu.html

    I hope some of this helps, good luck and go for it !
     
  3. jankjo

    jankjo

    May 22, 2002
    You may want to replace the pot, but they are cheap. You can get a new one for well under $10. Volume pots are linear and most of the time (some of the time?) tone pots are tapered. Which means that you turn a volume pot halfway, and the resistance cuts in half. If you turn a tone pot halfway, the resitance changes logrithmically. This is because the frequencies roll off log, not linear.
     
  4. Paul A

    Paul A

    Dec 13, 1999
    Hertfordshire U.K!
    Both pots are the same value i.e. 250k so you should not get any problems.
     
  5. Since you are going to the trouble to remove the tone pots to improve tone, consider installing a 3-way pickup selector switch such as found on the Fender RB5.

    Bridge-only, Both, Neck-only

    This will go a long way toward keeping the passive tone purity you desire. Anytime a passive pickup has another component in parallel in the circuit (another pickup, tone pot, volume pot, blend pot), the impedance and tone drops.

    An active preamp such as a U-Retro will let you isolate each pickup into its own high-impedance channel, and still provide full +/- EQ controls.

    Balance is another problem. Typically, most P pickups have significantly more output than a typical J type. The Retro active preamps have balance pots so you can match pickups with different levels.
     
  6. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Thanks for all the posts guys and the sites George. I will check them out later tonight. Bruce, why would I want a three way switch if I hook each pickup to it's own volume controll I can boost, mix, or cut each any way I want? I will have a volume knob for each. The tone will not be adjustable other than how I boost each pup. Am I missing something?
     
  7. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Replacing the pots is not a problem. I already have way more into this bass than I can ever get out of it so I am going to "play" my money out of it:eek: It was formerly a Fender P "foto lame" from Japan. I defretted it and sanded off that ridiculous FAKE finish. I am going to finish it in Cream White with a red tortise shell pickgard. SWWEEEEEEET:cool: With all this work into it I decided to add the Jazz pup in the bridge position. And, of course, I want to get it right;) Any suggestions on where exactly to put the pup?? And I am still cyphering the controls for the pups. All help/opinions here welcome. I am not electronically inclined but like the idea of seperate volume controls, plain and simple, for each pup. And I do have shielding for it. I will post pics when it is complete unless I totally blow it:( Not likely:rolleyes:
     
  8. Because passive pickups are very impedance sensitive. When you have two pickups in the circuit they are parallel and this reduces the impedance. Even with the pot turned all the way down the impedance drops considerably.

    Either use a 3-way switch to physically isolate each pickup (when solo'ed), or install an active preamp that connects each pickup to its own, high-impedance channel. This gives the best possible tone the pickup can provide. This is the reason guys remove the volume/tone pots and go direct from pickup to jack.
     
  9. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Thanks Bruce. It makes sense in that perspective.


    So from what I understand: I should go with a three way switch and a volume control for each pup? Then when I am using both pups I can adjust the output of each for the mix? Or Add a pre amp which will in effect give each volume control a more isolated control independent of the other pups output? Thanks Again Bruce. I appreciate your time and input. :confused:
     
  10. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    And this would be used usually for a bass with "one pickup"?
     
  11. You can remove tone and volume pots with multiple pickups. This requires the installation of a 3-position N|N+B|B switch like my RB5 uses. The switch physically isolates each pickup from the other in solo mode.

    I'm not familiar with a P+J tone, so I don't know if this is a useful combination or not. For me, a J+J (neck+bridge), and Bridge-solo are what I use on my J fretless. I never use Neck-solo.

    A two channel preamp such as a J-Retro will isolate each pickup, and give you internal balance pots to match the loudness of each pickup.

    Another thing to consider... is a P+J something you are actually going to use? That combination isn't for me. I run TI flats on my P and rounds on my J. I want massive percussive thump from my fretted P, and the bright fretless mwah from the fretless J. These tones are mutually exclusive, so I use two basses.
     
  12. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    That is why I chose to use a Jazz pup in the bridge position. It is deemed the most desirable there generally speaking. I have seen this set up on many basses and I "think" it will be killer on my fretless. I will use the P for blues/rock and the jazz when I want more definition and or punch. The jazz pup is a Basslines and is pretty hot. While the P pups are stock from Japanese P and are warm and pretty mellow.

    As usual I still don't quite get pup hook up. Know of any good sites off hand? What is the difference between a volume knob for each pickup and having a pan and volume knob?

    I am thinking now to go with converting the tone pot to a pan pot and then I will have a Pan and a volume. If I go with a three way switch, I won't be able to adjust the volume to balance the pups when both are on(center). Am I making any sense?