51 style p bass wiring

Discussion in 'Pickups & Electronics [BG]' started by The Wiz, Mar 20, 2014.


  1. The Wiz

    The Wiz

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    Hey all, i just got a fretless parts 51 style p bass and im having some trouble with the electronics. When it got to me, the volume and tone were bypasses and the pickup went straight to the output jack. It sounded great but i like having the volume and tone controls for obvious reasons. So i decided to wire them all together and since this is my first experience with bass electronics. I usually have had my tech do this type stuff but moneys tight right now so im doing it myself. I found a seymour duncan wiring diagram on the internet and i used that as my template. I got it all wired up and it worked, meaning i got a signal through my amp and the volume and tone worked, but the hum is insane! To the point of which hum is innacurate and its best described as an ear splitting buzz. Not to mention every time i touch a metal part of the bass it makes a very loud clicking. Despite how sloppy my soldering was, all the connections seem to be good and solid. Theres a ground wire that leads to the bridge, the control cavity has some shielding in there but its not entirely covered. Please tell me where i went wrong! Thanks. P.S. Sorry the pics are a bit hard to see.
    ImageUploadedByTalkBass1395371523.454454.jpg ImageUploadedByTalkBass1395371568.370699.jpg
    ImageUploadedByTalkBass1395371620.703546.jpg
     
  2. walterw

    walterw Supportive Fender Gold Supporting Member

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    check that you didn't wire the jack itself backwards, which would make all the metal parts "hot" and everything hideously noisy.

    also, did you run a wire under the bridge to ground? it's not in that diagram but you always need to have that.
     
  3. The Wiz

    The Wiz

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    I did run a wire to the bridge as my ground (the huge wire coming off of the tone pot). And the wires from the jack could be backward. The diagram i used referred to black and white wires but mine are the thick red and black ones. Im going to switch them and see what happens. Thanks!
     
  4. walterw

    walterw Supportive Fender Gold Supporting Member

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    instead of just blindly switching, look at the jack: the lug that's part of the "body" of the jack, including the threaded part, is "ground"; the lug that just connects to that prong that sticks up and contacts the tip of the cable plug is "hot".
     
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  6. Hopkins

    Hopkins Supporting Member

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    No offense man, but those solder joints are pretty rough. Bad connections can introduce a lot of noise into the circuit
     
  7. walterw

    walterw Supportive Fender Gold Supporting Member

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    agreed, but honestly i've never noticed a noise problem; with bad joints you get intermittent signal, and (rarely) a dull, weak signal, but i've never noticed a noisy signal (as in hum or buzz) from bad solder joints.

    OK yeah, if a ground is not really grounded that could make more noise.
     
  8. Hopkins

    Hopkins Supporting Member

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    Yeah, the grounds on the back of the pots don't really look as though they are making a very good connection. You very well may be right about the jack being wired backwards. Also that braided ground strap (Im assuming is the bridge ground) is totally unnecessary, a 24 awg wire would work just as well.
     
  9. The Wiz

    The Wiz

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    I switched the output wires and the hum is MUCH better, but im still getting a loud clicking noise when i touch metal parts of the bass. And no offense taken hopkins, i agree that my solder joints are pretty rough, but im pretty new at this and still learning. Im going to try and clean them up and see if that helps at all. Also, i know the braided wire isnt necessary but it was already grounded to the bridge when i got the bass so i just kept it. Thanks for the help and for dealing with my electronic inexperience haha!
     
  10. The Wiz

    The Wiz

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    Turns out im not a terrible solder-er, the tip of my soldering iron wasnt heating enough so i switched them and now it works waaaay better. I unsoldered all the old joints and redid them with the hotter tip so theyre much cleaner. Also switched out the braided ground wire for a standard one, and after all that, nothing changed and im still getting that awful clicking upon touching the bridge and control plate! I dont know where to go from here
     
  11. Hopkins

    Hopkins Supporting Member

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    Does it still make the clicking noise if you touch the control plate while you are touching the strings?
     
  12. yodedude2

    yodedude2 Supporting Member

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    i'm no expert, and it's hard to tell from the pictures, but i can't see that the tone pot is grounded to anything other than the bridge. it looks like you have the pickup, cap, and jack grounded to the volume pot, and the bridge/string path grounded to the tone pot. i believe you should have all grounds interconnected.

    try adding a grounding wire from the tone pot to the volume pot as well.
     
  13. Hopkins

    Hopkins Supporting Member

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    Its not necessary, as long as one pot is grounded, the control plate will ground the other one.
     
  14. yodedude2

    yodedude2 Supporting Member

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    excellent point. forget what i said. :atoz:
     
  15. The Wiz

    The Wiz

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    Im not sure hopkins, i havent bothered restringing it yet, but i would imagine not because if im touching the control plate i can touch the bridge and theres no clicking and vice versa. And i know the pictures are hard to see, but there is a connection between the volume and tone pots
     
  16. Meyatch

    Meyatch Supporting Member

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    When I bought the bass the controls weren't working, so I wired the pickup to the jack. I never bothered investigating, but there is a real possibility that one or both of the pots are bad.

    The pictures are pretty hard to make out, but it looks like the cap might be going to the wrong lug on the volume pot? The diagram calls for it to go to the top lug and it looks like it might be going to the middle lug. Its very hard to see in the pictures, especially with the reflection from the control plate.
     
  17. The Wiz

    The Wiz

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    Hey mitch! Ya the picture quality is pretty terrible but the cap is indeed going to the top lug not the middle one. Im starting to think youre correct about the pots. Especially the tone pot. It looks very small and doesnt even have the value listed on it... Seems odd.
     
  18. yodedude2

    yodedude2 Supporting Member

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    just for grins, try running the bridge ground to a different ground point, like the volume pot.
     
  19. The Wiz

    The Wiz

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    Already tried that as well. Tried the tone and volume pot. Im thinking one of the pots might just be bad. Going to replace them with cts pots and see what happens
     
  20. Scotty DelMar

    Scotty DelMar Supporting Member

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    Pot replacement would be a good idea. After checking all the leads for breaks in the wire and cleaning up [buy a solder sucker and use it] and re soldering everthing make sure the ground to bridge is actually making contact with the bridge. Sometimes the wire gets pushed down into the wood of the body and contact is lost. Those 5 bridge screws exert a lot of pressure. Let us know how you make out with this.
     

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