Potentiometers that are close to spec

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by Matt Gordon, Mar 24, 2006.


  1. Matt Gordon

    Matt Gordon Senior Member

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    I've had horrible luck with so-called CTS. 270K-350K actual for 300K spec, anywhere from 470K to 550K for 500K spec. Any online dealer screen them? I haven't had one single order get close and I tried almost every single online vendor. I'll accept 490/510 for 500K, or 290/310 for 300K. Any of you guys have a source? Thanks for any link/info!
     
  2. John Phillips

    John Phillips Member

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    That's not particularly 'horrible' luck... those variances are completely normal for electronics parts. None is outside +/- 10% from the specified value except for the 300Ks at up to 350K. Since pots are commonly specified at +/-20%, they're actually all within the correct range, from a manufacturing point of view. To do better than that you're going to need to pay more money for more carefully-selected ones, or simply to buy more than you need and screen them yourself.

    Normally, pot values aren't particularly critical in electronics because the circuits are designed to avoid placing too much reliance on them, exactly because they are not a high-precision part. But a passive electric guitar is much more sensitive to minor changes... and even at that, I'm not totally sure you'd be able to hear a 10K (2%) error on a 500K pot. And I do certainly think you can hear differences in pots (mostly to do with construction) as you'll know if you've read the 'guitar myths' thread ;). Of course if you can hear it in a listening test then it is significant.

    The real question is, does it matter? Have you tried the higher or lower value pots, and do they make the guitar sound worse? You might actually find you like the tone better at one end of the range or the other. 'Spec' values are not always the best.

    IMO.
     
  3. K-man

    K-man Member

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    Good luck. Even RS aren't that accurate. I just got a strat kit from them, and the 300k pots were between 250K and 280K.
     
  4. RL in Fla

    RL in Fla Member

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    What they said . If I need 4 then I buy 6 and pair up the closest matches
     
  5. Lex Luthier

    Lex Luthier Member

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    You close to any repair shops that buy CTS pots in bulk? I usually hit a shop here that stocks them in large numbers, and I bring my Fluke along and measure a bunch to find the ones I want.
     
  6. hipfan

    hipfan Member

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    I'm actually happy about the +/- 10% spec. It gives me more options when fine-tuning volume and tone pot values. Like John said, sometimes the out-of-spec pot can be just what the doctor ordered for a certain application.

    If you do want to pinpoint a little more though, BlackRose Customs is a great resource.
     

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