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Dimarzio J / Bart NTBT grounding Q

Discussion in 'Pickups & Electronics [BG]' started by epoxo57, Sep 1, 2005.


  1. epoxo57

    epoxo57

    Feb 17, 2005
    Perrysburg, Ohio
    Hey all,

    I just installed the DP123's in my Warwick Corvette Std w/ a Bart NTBT pre (master vol, blend, stkd bass/treble) yesterday and just got around to really analyzing the sound today. So far, great punch and tone as raved by many on TB (my reason for the investment), and a great improvement over the MEC's. Thing is, I think I have a ground problem since it buzzes when I do not touch the strings, bridge, or control knobs. I installed the pups just as the instructions say (red wires to middle lugs of blend pot, black wire soldered to white wire for each pup, and green ground wires to a central ground on the output jack). As far as I can see, the soldering seems good and everything in place. Battery is new and my other basses do not do the same.

    It's ok to ground all grounds to one connection, correct? Another wire at the ground goes to the bridge.

    Again, the sound is there, I just wouldn't think there should be a 'click' noice when I tap the knobs or bridge.

    Thanks in advance!!
    Scott
     
  2. DavePlaysBass

    DavePlaysBass

    Mar 31, 2004
    CO
    I would start by measuring with an ohm-meter between your star grounding point and all the other ground points in your wiring to make sure they are all hooked up as you think they are. The Bridge and the strings should be grounded.

    Dave
     
  3. scoote3639

    scoote3639

    Mar 16, 2004
    34952
    i have a set of dimmarzio model j and i cant use them anyehere with any preamp (i tried them all)! buzz,buzz unless i touch metal.very dissapointing but i have no solution as i have tried everything.maybe someone has a solution.....
     
  4. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    Epoxo,

    Is the cavity of your Corvette shielded with conductive paint? When you measure resistance between all the pot cases, does every pot case read 0 ohms potential to every other pot case and to the output jack ground?

    If the output jack ground isn't tied to all the controls via a wire or foil/paint shielding, you'll get exactly the kind of noise you describe.
     
  5. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    Scoote,
    Have you tried shielding the bass?
     
  6. scoote3639

    scoote3639

    Mar 16, 2004
    34952
    thanks for your reply but, yes everything is shielded with results as in previous thread...star grounding...etc.ive been a warmoth parts assembler for 10 years,built dozens of basses,with all p/up- preamp combos imaginable,encountered many unique, but solvable, buzz..noise...hum issues and have tried,unsuccesfully,to get either the model-j or the ultrajazz to quit buzzing.apparantley, as near as i can make out,the poles under the e and a strings are just not grounded.how difficult should that be to research and fix by DIMARZIO? until that gets resolved and dimarzio does a recall, mine will be paperweights.oh but im not bitter......
     
  7. epoxo57

    epoxo57

    Feb 17, 2005
    Perrysburg, Ohio

    Lyle:

    I was hoping you would chime since I came across your extensive shielding thread from an earlier post. I don't believe the cavity is shieled with paint, unless its a very dull finish. The NTBT controls have a wire that starts at the volume (soldered directly to the case) pot and is soldered to a washer that touches the reamining two pots....and ultimately the wire goes to the output jack ground lug. I haven't taken any readings, but today I resoldered my grounds and trimmed excessive wire and the buzz is still there slightly, but only mostly noticable if the treble pot is cranked which I never do anyway. If I tap on the knobs, it still does "click" tho. I just don't remember this happening before with the stock MEC's and Bart pre. The plus is is that the pickups do sound great and do not hum or buzz when each is soloed. Of course, I don't know how stage lights would effect the noise.

    This may not be a big issue when playing out, but I just got a Lexicon Omega and Cubase recording software and would like to record....quietly of course :D I've also considered reinstalling the old passive electronics since I have some good schematics to go by.

    scoote3639: I hope that this is not a typical issue with Dimarzio. I don't recall others talking about these issues, only good things...hence my investment.

    Thanks guys for the help or more if you can!!