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Tone and Volume pots

Discussion in 'Hardware, Setup & Repair [BG]' started by boogiedown, Nov 2, 2004.


  1. boogiedown

    boogiedown

    Nov 1, 2004
    The tone and volume pots on my bass suck, they keep cutting out on me and they seem to work mainly like an on off switch rather than actual volume control, i was thinking about replacing them and i was wondering if there is a difference between guitar and bass pots and if so where can i buy bass pots. also is there a difference between volume and tone pots?
     
  2. Bass

    Bass

    Nov 10, 2003
    Canada
    There is no difference in bass / guitar / volume / tone. The difference is in how they are wired. A capacitor separates the volume / tone potentiometers (pots). The pots are rated in "k"'s example 500 k vs 250 k. My pickups specify 250k pots so sometimes this is important.

    Someone correct me if I'm wrong: I'm no expert.
     
  3. If your bass has passive pickups the pots are probably 250K, but not always. You can look at the pot to see what value it is.
    I always use CTS pots when I re-pot a bass or guitar. They are USA made, butter smooth and great quality.
    You can get there here pretty easy, they even sell complete rewire kits.
    http://www.basspartsresource.com/electrical_pots.htm

    Scott
     
  4. Did you get this bass second hand? Sounds like someone did a crappy job of installing the wrong type of pot. The cutting out seems like a bad solder job and the "on off switch" sounds like you got a linear taper pot instead of an audio taper pot.
     
  5. boogiedown

    boogiedown

    Nov 1, 2004
    it was a cheap bass to start with so thats why the crappy pots are in there and i was the one who messed up the wiring. I installed new pickups and i guess i didnt do a very good job soldering them.
    The new pickups i added are humbuckers so does this mean i need a higher rated pot? like 500k?
    thanks for your help
     
  6. White_Knuckles

    White_Knuckles

    Oct 6, 2004
    First make a current wiring diagram.

    You can use a ohm meter across the two outer-most posts on the pot after desoldering other wires, capacitors on the tone etc. to get the total resistive value of the factory pots. Often they are stamped or labled with their value.

    There are cleaning slots cut into the pot body usually large enough for a spray can extended straw to enter. They are serviceable by removing the pot, place it on a rag (all wires still attached). Spray a shot of contact cleaner, potentiometer cleaner, tuner cleaner and in a pinch WD-40. Rotate the pot sweep through lock to lock several times after a few cleaner shots. I've refurbed many-o-noisy pots this way and had 'em last for years. When they're really dirty they can cut out like discribed as an on/off switch effect.
     
  7. White_Knuckles

    White_Knuckles

    Oct 6, 2004
    As far as the ohm value 250 vs. 500K, there is no effect to the overall output of the newer humbucker pickups. The resistance is added to the audio circuit to "roll off" pickup output. The volumn pot shorted or adding no resistance when wide open. Total pickup output is sent straight to the jack. Now as you rotate the control increasing resistance the output goes down up to 250-500k of rolled off total resistance. The tone and vol controls are an "audio taper" design to make a very slow change at first and get more rapid past the center point of rotation. Does it turn down properly?

    You can check with the pickup company to see what they recommend for typical values and diagrams of popular configurations. The tone circuit may have the wrong value of capacitor or pot if the tone doesn't shape properly as rolled down. Again, when the tone is maxed it bypasses the capacitor and pot value. basically if both controls are wide open you're straight through - pickup(s) to intrument out jack.

    This may not apply to battery powered active circuits which shape the vol and tone differently with more circuitry.