Solder/ground Dual-concentric Potentiometer Case?

Discussion in 'Hardware, Electronics & Parts' started by az2000, Aug 12, 2018.

  1. az2000

    az2000 New Member

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    I have a 2013 Epiphone Les Paul Special-II (1 tone, 1 volume). I thought it would be fun to replace the two pots with dual-concentric so I could have a tone/volume control on each pickup.

    I bought an Alps 500k dual concentric (audio taper on both pots). However, it doesn't look like a traditional pot:

    [​IMG] [​IMG]

    Question: Is it necessary to solder ground wire(s) to the case?

    I'm nervous about doing that because there's not much space to do that on the traditional location (a shaft and circ-clip are there). And the open-side design reveals white plastic blocks. I'm nervous if I solder to the side it might harm that plastic?

    Is there a sound benefit to putting the common connection on the case? Can I just connect grounds to a common wire? Maybe a ring-connector between the pot and wood, to ground the case (if it needs to be grounded)?

    I haven't had good experiences soldering things like this (a destroy them with heat). But, that's probably the cheap 20w iron. (Doesn't heat fast enough, so I heat the whole device?). I have a variable 60w coming. Hopefully my paranoia is misplaced?

    Thanks!
     
  2. GuitarBuilder

    GuitarBuilder Member

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    You can use the side of the pot for a ground connection.
     
    az2000 likes this.
  3. az2000

    az2000 New Member

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    Thank you for your reply. I ended up using a wire-connector ring:

    [​IMG]

    I'm going to use a bare solid 14ga(?) wire between the pots, and solder ground wires to that bus wire.

    Hopefully that's equivalent to soldering directly to the pot. When I posted, I was nervous that there could be some tonal difference between those two ground methods. (But, it's definitely good to know that an experienced person would have soldered to the side. I feel better about trying that eventually.).

    FWIW: what I'm doing is documented in this thread: Epiphone Special-II LTD mod: 2-vol, 2-tone, dual-concentric pots . Originally I thought this would be a simple project. Just put it all together. But, it's been more complicated. (I like it though.).
     
    Last edited: Aug 22, 2018
  4. GuitarBuilder

    GuitarBuilder Member

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    There's as much tonal difference between ground connections as with different pick guards! Just use a multimeter to ensure you have a low-resistance connections and you're fine!
     
  5. rgraf

    rgraf New Member

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    If you're worried about heat, then use eutectic alloy solder (63/37, rather than the usual 60/40. The eutectic alloy has the lowest melting point, and also the lowest glass transition temperature, meaning that it melts and crystallizes the fastest, rather than softening slowly. Having enough heat is also important, as you mention. As for the spade lug you are using, get some contact enhancer, like Cramolin, to ensure a good contact and minimizing oxidation potential anomalies.
     

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