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Only one side of the pickup is active?? Help :)

Discussion in 'Pickups & Electronics [BG]' started by Jeffrey A-Bomb, Nov 1, 2002.


  1. Jeffrey A-Bomb

    Jeffrey A-Bomb Drink Coffee & Destroy Supporting Member

    Oct 14, 2000
    Silver Spring, MD
    I've got a fully functional bartolini mk-1 active soapbar pickup that I'm trying to run to straight to the jack (no knobs). This is in a 6 string project fretless bass of mine and it's the only pickup that is on it. The problem is that when it's hooked up, powered, and grounded properly, only the low notes work (this is a 6 string fretless.. so b-e-a) and the d-g-c don't have any output. I'm not sure how to fix this.. I've tried a few combinations of wiring on the output jack but with little luck. Any help? Do I have to have tone/volume knobs? This will sound really nice once I get it working and i'm curious as to what the problem is.. Thanks.
     
  2. Jeffrey A-Bomb

    Jeffrey A-Bomb Drink Coffee & Destroy Supporting Member

    Oct 14, 2000
    Silver Spring, MD
    *Bump* Somebody has to has some sorta suggestion ;)
     
  3. Bonafide

    Bonafide

    Oct 15, 2002
    The magnets inside a soapbar type pickup (Especially one as long as a 6 string) are staggered like a P-bass pickup (Sometimes like a reverse P).
    It is very possible and mostly probable that the magnet that is meant for the higher 3 strings has been deguassed.
    The pickup works so you know it isn't anything to do with the electronics.

    You do not need a volume control or tone control to have your pickup working correctly. In fact I would have suggested you take them out of the scenario if you had brought this problem up with them in it.

    If the pickup is epoxxy potted, which It most likely is, then there is no way to fix it.

    Another POSSIBLE scenario is that there are poles under the epoxy and not bar magnets. The string alignment with the higher strings is 'off' to the point that the strings themselves are in between the poles and not under them. I have seen this happen alot when people try to use 5 string pickups on a six string. Truth is that is rare considering most active bass SOAPBAR pickups use bar magnets in a stagger pattern.

    Reverse the pickup and see if you get the same results.

    Best of luck.
     
  4. Carey

    Carey

    Jan 18, 2002
    Redlands, CA
    Bartolini pickups sometimes have pins and stuff sticking out the bottom. If your pickup cavity is shielded you may be shorting some of these pins against the shielding. It could also be a loose wire on the bottom of the pickup. IMO, it would be highly unlikely that there would be a problem internally.
    Good Luck
     
  5. Bonafide

    Bonafide

    Oct 15, 2002
    I agree that there is nothing wrong with the internal pre-amp, if there was the pickup wouldn't be working at all. As for shorting out on 'pins and stuff', that is a possibility though it would be shorting out the whole pickup and not just 1/2. The pre-amp powers the pickup as a whole. The only 'seperating' factor (Which seems to be his problem, since only 1/2 of the pickup works) are the magnets. Magnets can go bad easier than most people think. Thats is what led me to that conclusion.
     
  6. Showdown

    Showdown Supporting Member

    Jan 21, 2002
    Honolulu, Hawaii
    Bartolini MK-1 pickups are passive - there is no preamp in the pickup itself. It is normally used with the MK-1 preamp (which is external to the pickup), like in the Lakland Skyline 55-01, but it has no preamp of its own.
     
  7. Bonafide

    Bonafide

    Oct 15, 2002
    Cool. That makes it even less complicated. Does it have 2 coils or one? If it is passive then my guess is that one of the coils is broken (If it has 2). That or one of the magnets is dead.
     
  8. Showdown

    Showdown Supporting Member

    Jan 21, 2002
    Honolulu, Hawaii
    It has 2. The Lakland web site calls it a "split-coil soapbar", which would make it like a P pickup. There are two wires coming off of the pickup (on my Lakland, I assume that they are all the same), a shielded "hot", and a ground, with both the shield and the ground wire attached to ground. This indicates that the 2 coils are wired in series, so if one had a break in the wiring then neither coil would work. That tells me it is probably the magnet.