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Bart NTMB install help

Discussion in 'Pickups & Electronics [BG]' started by Edwcdc, Nov 21, 2003.


  1. Edwcdc

    Edwcdc I call shotgun!

    Jul 21, 2003
    Columbia MD USA
    Hey Guys,
    I am installing a Bartolini NTMB 3 way preamp in my Toby Pro 6. It is the prewired harness. I will be keeping the stock pickups. The pickups have three wires. One wire is heavy and has yellow braided insulation. I'm pretty sure I traced it to ground. The white wires currently go to seperate places on the circuit marked input front, and input rear. I'm pretty sure that the white wires go to the upper and lower of the middle lugs of the blend pot on the new preamp. The red wires are currently soldered together to a common location on the board. What do I do with these two red wires? Do they go to the red wires on the battery? Will these pickups work with this new preamp?
    The soldering iron is on, and I have a gig tomorrow night. :D

    Thanks in advance
    Ed
     
  2. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    OK, I don't know the Toby Pro basses, and the musicyo.com website doesn't give too much information.

    It sounds like these are active pickups, given the red wire. If you're keeping these pickups, you'll need to splice those red wires in with the red battery wire. You might start to run into headroom issues running both pickups and preamp off of 9v.

    you'll run into some impedance issues with the Bart blend pot - that's probably 250k or 500k, look at your existing blend and volume pots and see what impedance it is - it should be written on the side or back of the pot. It might have a number in front of it or something at the end, but the number (the impedance) is important i.e. A250, A25. You should look into using pots with appropriate impedances - guitarelectronics.com sells 25K blend / master volume pots.

    White wires: yup, sounds right - they should be the hot signals.

    Braided wire: ground sounds right.
     
  3. Edwcdc

    Edwcdc I call shotgun!

    Jul 21, 2003
    Columbia MD USA
    Thanks for getting back so quick. The blend pot is 250k. I guess instead of messing with the harness, I should just tell my wife it won't work with what I have. I will have to spring for the new Bart pickups.:D I think it will be way better in the long run. You are the man davidmwilson, thanks for lending your know how.
     
  4. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    that sounds like a good excuse for a pickup upgrade :)

    No problem, you're welcome. I learned what I know from hanging round Talkbass (that and my natural geek curiousity), so I'm glad to return the favor for someone.
     
  5. Edwcdc

    Edwcdc I call shotgun!

    Jul 21, 2003
    Columbia MD USA
    you'll run into some impedance issues with the Bart blend pot - that's probably 250k or 500k, look at your existing blend and volume pots and see what impedance it is - it should be written on the side or back of the pot. It might have a number in front of it or something at the end, but the number (the impedance) is important i.e. A250, A25. You should look into using pots with appropriate impedances - guitarelectronics.com sells 25K blend / master volume pots.

    Are you saying that there is no way it will work with the current blend pot. I keep reading posts where guys are saying this preamp just drops right in. They never mention anything in regards to this. I can solder my a** off but I don't know much about why things work. David? sorry to bother you again :meh: I'm just getting itchy to do some modifications:)
     
  6. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    You should get a blend pot of an impedance matching that on your current preamp, or instead of a V/B setup solder a V/V setup - this can be easier to do sometimes, as it can be difficult to get (for example) 100k blend pots. guitarelectronics.com sell a 25K blend pot, if that helps.
     
  7. Moo

    Moo Banned

    Dec 14, 2002
    Oakland, CA
    Have you pulled these out the front of the bass? I'd be surprised if they were active pups in a bass that cheap, er, inexpensive ;)

    The yellow could be sheilding or ground of some kind with white hot leads and red pickup grounds. Either way it should work at center detent with the Bart and if you find the pan pot works way whacky, like the pickups roll off real quick when you leave center, then get a new pot.

    I would make sure they are passive or active before you wire the red wires to a battery.
     
  8. Edwcdc

    Edwcdc I call shotgun!

    Jul 21, 2003
    Columbia MD USA
    Ok I got bored Wednesday night and plugged the soldering iron in. I wired in the new preamp with existing pickups. No hums buzzes or other strange sounds. The red wires are power wires and I hooked them up to the battery. The bass sounds good and all of the controls seem to work. It is a little hot so I have the trim pot backed all the way down. The blend knob could be a little smoother. I am ordering pickups and will replace them as soon as I can find some that will fit.
     
  9. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    Yup, that's the issue you'll have with the blending. If you always leave it at center, you may not have a problem but may have an issue if you ever sell it and have to explain the issue.

    As to the previous poster, I based my assumptions on the control cavity photo of the Toby from the musicyo site.

    [​IMG]
     
  10. Edwcdc

    Edwcdc I call shotgun!

    Jul 21, 2003
    Columbia MD USA
    Thanks David I guess I got a little too bored for my own good and couldn't leave the thing alone. The pic you posted looks like the same preamp that was in the bass. The only difference is that my pickups have a third wire for power because they are cheap but active;) Will I damage the preamp or anything else running it this way? I can always put the old preamp back in if that is the case.
     
  11. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    No, you won't damage the preamp so don't worry.
     
  12. Edwcdc

    Edwcdc I call shotgun!

    Jul 21, 2003
    Columbia MD USA
    I played two gigs this weekend with the new preamp. I can't get over how much of an improvement this has made in my tone. Every time I would play a little run or anything else interesting the guitar player would look over at me and ask me if I am playing a new part. I told him that he is finally hearing what I'm playing. The first night he said I was too loud.:D
    I just ordered some Bart's. I can't wait.