300k Audio Pots

Discussion in 'Pickup Forum' started by zozoe, Jul 31, 2020 at 10:01 PM.

  1. zozoe

    zozoe Strat-Talker

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    Hi all & hope you are well~~ I'm having an impossible time finding some 300k's, or darn close to it. I read that if you put a 1meg resistor across a 500k pot, you end up with 333k,,, Any thruth to this &:if so, exactly where would this resistor go?
    Many thanks in advance.
    Kenny
     
  2. sjtalon

    sjtalon Senior Stratmaster

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  3. zozoe

    zozoe Strat-Talker

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    Yeah, I've contacted them all in the past & recently, & they all say the same thing, that there's a 20% tolerance & they can't measure them. ONLY Guitarelectronics.com have done it in the past, and will hopefully do it again. They were all in the mid 290's. So, I'd like to also try the resistor trick & see what happens. What would be the formula for figuring out what values get you where? I'm shooting between 300 & 330K.
    Many thnx, & be well~
    Kenny
     
  4. JB74

    JB74 Senior Stratmaster

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    The 20% tolerance is the standard tolerance in most carbon track rotary pots. If you want something more precise you will pay through the nose for it.

    Emerson will likely have their own spec CTS pots (around 8%) and they are pretty pricey.

    Alternative is try Bourns PDB241-GTR01-304B0

    I find them usually to be pretty close to ± 8-10% despite the 20% claim. If you want to take the chance, just select the best one from the batch you buy.

    Not sure if you have 18 or 24 knurl knobs, but that is always a consideration to be considered.

    Try farnell/element14/mouser/RS or Digikey or octopart etc.
     
  5. sjtalon

    sjtalon Senior Stratmaster

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    If you want to worry about tolerance, what about the 500KΩ pot you use :D

    Then there is resistor tolerance........................:eek:

    as JB said:>I find them usually to be pretty close to ± 8-10% despite the 20% claim. If you want to take the chance, just select the best one from the batch you buy.<

    A person isn't really going to hear jack diff in 10%.

    In answer to your question, 750K I believe is the animal.

    Happy pikcin'
     
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  6. PCollen

    PCollen Senior Stratmaster

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    " What would be the formula for figuring out what values get you where? I'm shooting between 300 & 330K."

    Rt = R1 x R2 / (R1 + R2)

    Rt = 1M x 500K / (1M + 500K ) = 333 K (approx)
     
  7. jvin248

    jvin248 Senior Stratmaster

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    .

    Resistors in parallel calculator
    https://www.1728.org/resistrs.htm

    Getting a tighter than 20% tolerance is not important .. a 1% tolerance pot won't sound better to you if you like your guitar brighter or darker sounding than the average guitar of that model/pickup.

    Best way you can find what you want ... get a multi-meter (Harbor Freight has some for $7 that work fine) and order a box of five or ten volume pots for your guitar. Then use the meter to measure them all and select the highest or lowest in the group. One batch of five pots I ordered last had 485k to 550k actual measurements of pots marked "500k" to select from.

    Higher kohm is brighter, lower is darker.

    Don't forget you can do the same when selecting tone capacitors. Lower uF lets more highs/sparkle/presence through.

    .
     
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  8. tinkertoy

    tinkertoy Strat-Talker

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    1/r1 + 1/r2 = 1/rt

    1/1,000 + 1/500 = 1/rt

    .001 + .002 = .003

    1/.003 = 333k
     
  9. Believer7713

    Believer7713 The Pink Bunny Frankenstein Strat-Talk Supporter

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