Old CTS Potentiometer's How Do You Tell??

Discussion in 'Tube Audio' started by tube-a-lou, Jan 13, 2018.

  1. tube-a-lou

    tube-a-lou Super Member

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    On the older CTS pot's how do you tell if there audio or linear?
     

     

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  2. BinaryMike

    BinaryMike Pelagic EE Subscriber

    Adjust the shaft to mid-rotation and measure DC resistance between the wiper and each end. If the resistances are near equal, then it's a linear pot.
     
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  3. gadget73

    gadget73 junk junkie Subscriber

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    As a corollary, if its roughly 90% to one end and 10% to the other, its log / audio taper. A 100K audio taper pot will give about 10K to one end and about 90K to the other when set to mid rotation.
     
  4. tube-a-lou

    tube-a-lou Super Member

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    Thanks guy's, I tested a few and found one I thought was good was a reverse and a
    linear.
     
  5. tube-a-lou

    tube-a-lou Super Member

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    4,424
    Could you hear any difference in sound with a CTS pot if I measure one at 1.012meg and
    another around .867meg?
     
    Last edited: Jan 15, 2018
  6. BinaryMike

    BinaryMike Pelagic EE Subscriber

    It's very unlikely that you would ever hear any difference between channels due to this amount of difference in total end-to-end resistance. The main problem with economy dual volume control pots is poor tracking at low volume settings, which is an unrelated type of imperfection.
     
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  7. gadget73

    gadget73 junk junkie Subscriber

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    For volume on a single channel amp, not likely. As a 2 channel amp for volume, maybe, tone control, probably.

    Honestly its one of the things I hate about old pots. Not sure if they were that bad about tracking when new or if they got worse with time but either way its crap. Modern pots that work right are way more better.
     
  8. tube-a-lou

    tube-a-lou Super Member

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    I want to use it in the tone control in my Fender Deluxe amp.
     

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