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replacement for 2N3819 transistor?

Discussion in 'Effects, Pedals, Strings & Things' started by Carstens, May 21, 2011.

  1. Carstens

    Carstens Member

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    Chicago, IL
    Anyone familiar with these JFET transistors. They are 10mA 25v.

    I was wondering whether there is another similar JFET that would have a higher output to use in a distortion pedal that seems to be low in overall volume?
     
  2. jdel77

    jdel77 Silver Supporting Member

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    Just google the equivalent, or the datasheet, which will tell you the gain and pinout. J201's get a lot of love for boost/clipping applications in dirt pedals.
     
  3. 8len8

    8len8 Member

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    The transistor itself is not likely to be directly impacting the volume. The feedback network (resistors) around the transistor set to final volume. You'll need to tweak them.
     
  4. Carstens

    Carstens Member

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    i'll take a look. not necessarily the transistor bias resistors to ground, but others around that circuit?

    thanks for the input.
     
  5. CodeMonk

    CodeMonk Member

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    Go here: http://www.datasheetarchive.com/
    Enter the part, then scroll to the bottom of the page where it says "Cross Reference".
    Might be a good idea to get the datasheet as well.
    With VERY FEW exceptions, I won't use a part if I can't find a datasheet for it.

    BTW...if anyone can find a datasheet for a 2N440, I would appreciate it. And no, I didn't miss a number there.
     
  6. 8len8

    8len8 Member

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    It might not be that simple. If it was a simple "common source" FET amp then I'd say look for one or more resistors between the FET drain and the gate. There's only 2 issues:

    1- Most pedals have multi-stage complex circuits with more than 1 feedback loop.
    2- The stuff I talk about will likely change the distortion, maybe not just the volume.

    You should really take the pedal to a tech who knows that pedal...
     

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