What’s the easiest way to fix a scratchy pot?

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by RedRockRoy, Jan 26, 2005.

  1. RedRockRoy

    RedRockRoy Member

    Dec 27, 2004
    The volume dial on my matchless sc30 makes a terrible scratchy noise when I turn it. I really don’t want to disassemble the amp and replace the pot unless I absolutely have to. Any suggestions?

  2. saros141

    saros141 Guest

    You shouldn't have to replace the pot, all it needs is a shot of contact cleaner. Best done from inside the amp so you can get the little straw right in to where there's an opening in the pot near the lugs. And you can do them all.

    If you are loath to disassemble, you might try taking the knob off and tilting the amp so the pot's bare shaft is pointing up. Pull the shaft up a bit and this should widen the gap between the shaft and the bushing. Spray contact cleaner in there. Actuate the pot (spin it). Spray again, spin it, get it worked in, let gravity take it inside. Might do the trick.
  3. loverocker

    loverocker Member

    Nov 3, 2003
    If that doesn't work, then it's possible that the pot is fine, but the scratchiness is caused by a failing cap (which lets a small DC voltage get on to the pot). If so, that cap would need replacing.
  4. Blue Strat

    Blue Strat Member

    Aug 2, 2002
    Sterling, VA (not far from Washington DC)
  5. Wakarusa

    Wakarusa Member

    May 7, 2004
    Indianapolis, IN
    Highly recommend the combined treatment of Caig DeOxit D5 (red can) and Caig MCL (blue can)

    D5 is a cleaner, MCL is a lubricant (to restore what you stripped away with the cleaner).

    Give a quick shot of D5 into the back of the pot, cycle stop-to-stop five or ten times, let it dry, shot of MCL, cycle again, play.

    In my personal experience spray cleaners don't work well when applied from the front along the pot shaft. You really need to get at the back to be effective. All of the usual caveats about high voltage and death by electrocution apply.

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