1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

How badly can you screw this up?

Discussion in 'Pickups & Electronics [BG]' started by anonymous278347457, Dec 31, 2005.

  1. anonymous278347457

    anonymous278347457 Guest

    Feb 12, 2005
    I was thinking of changing some pickups on my bass. But im being put off by all this Polarity and grounding stuff.

    I was wondering if i put my pickups in backwards or something will it damage anything? eg. pots, pickups etc
  2. fretlessrock

    fretlessrock Supporting Member

    Aug 8, 2002
    If it is a passive setup then you won't damage anything, but it might not sound right. Regardless of what they know *now* most folks started by incorrectly wiring a passive bass or guitar, then fixing it.

    In an active setup where you have active pickups or a preamp, you can damage the electronics by incorrectly wiring the power supply. I can't think of a way that you would damage any outboard gear, but maybe someone else can. I'm sure that wiring 9vdc to the output would be interesting...
  3. anonymous278347457

    anonymous278347457 Guest

    Feb 12, 2005
    On an active setup is the power supply just + and -? or is there something else. Im assuming that pickups and preamps are all labeled right?
  4. fretlessrock

    fretlessrock Supporting Member

    Aug 8, 2002
    There are no rules on this. If there is a single 9v then it is usually straightforward 9v with the ground side switched on the rig and sleeve of a trs output jack. 18v systems can be +18v or +/- 9v.

    Some preamps like the East units have some markings on the pc board, and many like the Aguilar don't have ny markings. The aggie is just an epoxy-sealed black box with about a dozen wires poking out of it.

    the best advice I can give is to draw diagrams of the current setup before hacking on it, label wires, take pics if you can, get the docs for any pickups or preamps, and read up on the type of bass you are working on. Fender has a lot of great wiring diagrams on the mr. gearhead website.

  5. luknfur


    Jan 14, 2004

    I've done everything wrong more than once and I doubt I've missed anything. A 50/50 probability shot for me I've learned from experience is 33/66. The 33 being the chance of getting it right. I've never smoked anything in installing dozens of preamps, although I've heard it can be done. For sure don't try sticking pickup leads directly to a 9v battery though.

    Just don't expect anything to be a drop in and go smooth and you'll be fine. The polarity thing is no big deal and affects nothing and in fact is the means for getting an out of phase tone - very popular for blues guitar but not generally a sought out bass tone.

    Definetly KNOW the measurements of any pups before you buy so you KNOW they will drop in without routing - J's for example can vary 1/8" in length (not considering bridge/neck variations).

    If your staying passive with passive, you can use the existing harness in the bass and won't have to touch the pots or the grounding. Soldering grounds pot backs to me is the most challenging soldering job in harness wiring. That and the close quarters wiring required for a mini-switch loaded with wires maybe. Even that you can skip by clipping the existing pup ground leads an inch or so back from the pots, getting some shrinkwrap cheap (Home Depot carries it of all places), and just soldering the pup lead to that and heating the shrinkwrap with the solder iron barrel till it's snug. Don't forget to thread the shrinkwrap onto the lead before soldering. Basically a 15 minute job from start to playing.

    You may need to play around with pup height a bit but if you measure the difference in thickness between the two different sets of pups and allow padding for the difference, the new pups will be the same height. If you use something firm but with some give for padding (some of the common packing materials work well), you won't have to spend an our jacking around with various pad heights if it needs to be altered.