Oversized Amp knob Trick

Discussion in 'Amp Central Station' started by Intubator, Jan 6, 2021.

  1. Intubator

    Intubator Tele-Holic

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    I just built this amp and when I got to the point of putting on the control knobs I realized that the pot shaft diameter and knob diameter were mismatched to the point that with the knob set screw tightened, turning the pot shaft made the knob rotate in a very noticeable eccentric offset motion. Here's my solution to share with folks who may have run into a similar situation by making a fix with a plastic drinking straw, and it perfectly centers the oversized knobs snugly on the shaft and gave it a little extra grip and the set screw some extra "bite".

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    These were Alpha pots and the straw had to be gradually pushed onto the shaft, it is a snug fit.
     
  2. strat a various

    strat a various Friend of Leo's

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    Good idea.
    I've been using heat-shrink for that.
     
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  3. J-Flanders

    J-Flanders Tele-Meister

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  4. 11 Gauge

    11 Gauge Doctor of Teleocity

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    +1 on the heat-shrink, especially if you can find the stuff that has teflon in it (I think).
     
  5. schmee

    schmee Doctor of Teleocity Ad Free Member

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    Do those knobs have a brass liner or just plastic? I think the brass lined ones are much better, and the plastic ones strip out the set screw super easy. (dont ask how I know!)

    But either way, I use CTS pots and dont have that fit problem at all... Use some Alpha's in certain positions too...? Is that a metric pot or something?
     
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  6. Intubator

    Intubator Tele-Holic

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    Yes these are brass lined knobs from AE supply. Don't think they are metric pots, but the knobs may be... IDK. Either way the straw seems to be a perfect adapter, the knobs are very snug and the spacing is uniform.
     
  7. zombiwoof

    zombiwoof Tele-Afflicted

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    You can get Alpha pots with either metric 6mm shafts or standard 1/4" (6.3mm) shafts. You're putting standard knobs on metric shafts. As long as the fix works, I'd say you're OK.
    Al
     
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  8. StevesBoogie

    StevesBoogie Tele-Afflicted Ad Free Member

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    I saw this trick once in an episode of MacGyver!
     
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  9. craigs63

    craigs63 Tele-Holic

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    What color straw has the best tone, or does it depend on if it's a bass vs. treble control?
     
  10. foundjoe

    foundjoe Tele-Holic

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    And you’re keeping the oceans cleaner and saving fish.
     
  11. Mark the Moose

    Mark the Moose Tele-Afflicted

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    I think that makes it louder...
     
  12. brookdalebill

    brookdalebill Tele Axpert Ad Free Member

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    Brilliant cheap fix!

    I’m a big fan of Fender “cupcake” knobs.
    I have them on one of my amps, and four of my guitars.
    They’re lightweight, and it’s easy to see where they’re set.
    I only recently became aware that some cupcakes have metal inserts, and some don’t.
    Now when I go to guitar shops, I always see if they have the ones with the inserts.
    I ordered a good supply of the brass insert/sleeves from AllParts.
    The OP’s solution is brilliant.
     
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