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EMG / grounding question

Discussion in 'Pickups & Electronics [BG]' started by cdb, Apr 12, 2005.


  1. cdb

    cdb

    Jan 12, 2004
    phila, pa area
    How bad is this?

    I have 2 EMG DC pups and a BQC system. I soldered everything together and went downstairs in the basement to test it. Since I was working on a body only, no bridge, no neck, I held another bass over the pups to test if there was a signal. And plugged the whole mess int an amp ...In my barefeet.

    I touched some solder joints. There were crackling noises. I got a signal, but it was faint, and sounded out of phase. I still get microphonic noises when I tap on the pups.

    Questions:
    1. Did I completely fry the whole deal by stupidly not wearing shoes and inadvertantly grounding out on the basement floor when I touched wires?

    2.I cannot tell from the schematic where to plug in the e-z connect on the bottom of the pups. White wire to the left or right?

    Thanks in advance for your help.
     
  2. adam on bass

    adam on bass Supporting Member

    Feb 4, 2002
    New Braunfels, Texas
    Endorsing Artist: Spector, GK, EMG and D'Addario
    there is a little arrow on the connector that lines up with another on the pickup. that is how you know what goes with what. i would check your white wire connections to the board. sounds like they might be going the wrong way.
     
  3. cdb

    cdb

    Jan 12, 2004
    phila, pa area
    Thank you sir. I did not notice an arrow... but I am old and half blind anyhow....
     
  4. adam on bass

    adam on bass Supporting Member

    Feb 4, 2002
    New Braunfels, Texas
    Endorsing Artist: Spector, GK, EMG and D'Addario
    It's not really an arrow, more of a diamond.
     
  5. cdb

    cdb

    Jan 12, 2004
    phila, pa area
    i will look for it tonight when i get home...
     
  6. I think you just didn't have enough ground on the instrument. Most guitar electronics have a ground wire that goes to the bridge (yours was removed) and uses the strings and your body to help with grounding noise. Your pickups are grounded to the volume and tone pots, and this usually always ties together to the wire that goes to the bridge.
    That crackle noise you were mentioning sounds much like ground problems on basses were the bridge wire wasn't making good contact under the bridge. Some manufacturers simply stick a bare end of a wire under the bridge, and the force of tightening the bridge down makes contact. Sometimes this force presses those bare wires down into the bass's finish just enough to prevent good contact. I prefer to at least lightly-tin that bare wire with a touch of solder before tightening it under the bridge. Not absolutely necessary, but I've had good luck isolating ground problems that way.

    If you haven't yet, you should try assembling the bass with strings on it, making sure you have a good ground under the bridge.

    It's a good idea not to play barefoot on a concrete floor. If your electrical wiring is not grounded properly, you could be in for a nasty shock. I had a few of those..

    Mag...
     
  7. alibloke

    alibloke

    Dec 17, 2004
    Bristol, England
    Luckily active EMGs like the DCs don't require a bridge ground to stay quiet, which is one of their main selling points. The Bridge ground itself can present a shock hazard, (if you are connected to an old dodgy amp) for instance....

    They are also sealed under vacuum to eliminate microphonics, and are also low impedance and shielded so don't pick up radio signals from your hardware or strings.

    To be honest I'm not sure whats wrong. Sounds like you've got something wired backwards maybe? :confused:
     
  8. cdb

    cdb

    Jan 12, 2004
    phila, pa area
    One of the quick connects had a diamond, the other didn't, but I simply hooked it up the same way... and it seemed to help the out of phase problem, thanks for the tip...
     
  9. adam on bass

    adam on bass Supporting Member

    Feb 4, 2002
    New Braunfels, Texas
    Endorsing Artist: Spector, GK, EMG and D'Addario
    You got it. Don't ground it as previously mentioned. No need to Ground Active EMG's as previously mentioned. We are glad to help.
     
  10. cdb

    cdb

    Jan 12, 2004
    phila, pa area
    The pup instructions clearly say "Caution-- do not ground to bridge" which was why I got all panicky about grounding to the basement floor in the first place. This my first active bass I have built, all my others have been passive 1 or 2 pup models...

    thanks for your help
     
  11. alibloke

    alibloke

    Dec 17, 2004
    Bristol, England
    LOL!! Now I have a question! :D

    I just took the EMG P5J set out of my Yamaha, to check which way they were wired up.....

    Looks like I have an older version of the EZ plugs which only have three pins and no arrow to indicate which way to connect the pickups!

    Okay question is, if I have the pickups in front of me, sensing side face down so that the 3-pin EZ connector faces me, does the 'hot' wire go on the left or the right? Guess it would be the same as for yours? :confused:

    At the moment the red wire is on the left....
     
  12. cdb

    cdb

    Jan 12, 2004
    phila, pa area

    Well, I am at work now, with no pup in front of me... as I remember, the white wire was to the left....but my memory has its faults
     
  13. alibloke

    alibloke

    Dec 17, 2004
    Bristol, England
    Okay, thanks cdb I'll give it a go.... :)
     
  14. alibloke

    alibloke

    Dec 17, 2004
    Bristol, England
    Okay, tried swapping the polarity round, but the output went dead, so guess I had them round the right way in the first place!!

    Took the opportunity to raise the pickups closer to the strings though, and things are sounding sweet! :bassist: