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Saturday, November 22, 2014

JFET Boost

Here's a quicky. It's an old Dragonfly design and was my first perf build.



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22 comments:

  1. fredSeptember 22, 2015 at 10:30 PM

    Hi, this is a clean booster?

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  2. UnknownSeptember 28, 2016 at 5:01 AM

    Yes clean booster ,very very perfect

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  3. SkaybluesDecember 21, 2016 at 8:35 AM


    I built this pedal with mpf102 and it sounds ugly, is it possible that the replacement you use is not the right one?
    The transfer image lacks a hole for a resistance of 2.2k?

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  4. DarkanumFebruary 6, 2017 at 3:13 PM

    What is a replacement for J201?

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    Replies
    1. IvMFebruary 7, 2017 at 11:56 AM

      Try 2N5457, or F245A. I used both, and works great.

      Delete
  5. ThaipedalstompboxJuly 15, 2017 at 11:55 PM

    https://www.youtube.com/edit?o=U&video_id=EITs60ZwEUI

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  6. UnknownOctober 11, 2017 at 11:08 AM

    Does this scheme work or do I need to change something in the leyout ?

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  7. UnknownJanuary 25, 2018 at 1:39 PM

    To whom it may concern you can use a j113 if you change the 22k from 9v to a 10k just make sure to check pinout on transistor.

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  8. ZeDJuly 3, 2018 at 9:33 AM

    So, if you use a, say, 50k trimmer in place of the 22k bias resistor, you should be able to use other jfets and bias accordingly, right?

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  9. Effects LayoutsJanuary 27, 2020 at 7:53 AM

    The pot is wired off board. The pads labeled "Boost 1" and "Boost 3" tell you which lugs to connect. Boost 2 is the circuit output, and the pot is a 100k audio/log taper. See the General Layout Notes tab for offboard wiring info.

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  10. JohnJanuary 31, 2020 at 5:31 AM

    For caps, use caps polar or non polar?

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  11. Effects LayoutsJanuary 31, 2020 at 12:13 PM

    Polarized

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  12. JohnJanuary 31, 2020 at 12:30 PM

    This comment has been removed by the author.

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  13. JohnFebruary 3, 2020 at 4:34 PM

    Still not work, i try with J201 and the same value of resistor an caps , but didnt work.

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  14. UnknownMay 18, 2020 at 3:13 AM

    Does anyone know if this would work off 12v.building it into preamp section of a micro amp project. If not I can add another stepdown

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    Replies
    1. Effects LayoutsMay 18, 2020 at 9:56 AM

      You might need to adjust the 22k resistor going from voltage to drain, but I would think it'd work fine on 12v

      Delete
  15. UnknownJuly 15, 2021 at 5:12 PM

    few questions:

    can i use this with a dynamic mic without distortion? or there's some kind of problem in impedance or smthing?

    can i replace this with a 2sk170bl? any ultra low noise replacement with the same pinouts as j201?

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  16. Ayah akmalMay 16, 2022 at 11:27 AM

    Permisi saya membuat ini dengan 2n5458 dengan potensio B100K suara terdengar kecil...
    Ada yang dapat membantu saya

    ReplyDelete
  17. EMedlinAugust 22, 2023 at 4:14 PM

    Just completed this. My first attempt at using non strip perf board. I think i like it better. I get more of a sense of what is actually happening this way. It worked by the way. Although it sounds bad at low volume. Crackly. Im sure its my soldering though.

    ReplyDelete