This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Saturday, May 16, 2015

Simple JFET Buffer

Here's a simple one for your Saturday. As the name implies, this is a simple buffer based around a JFET transistor. This layout follows the schematic from Jack Orman's great article on Basic Buffers. Thought this would be useful if you want to add an input buffer to an existing pedal or to a project that doesn't have one.


22 comments:

  1. Works like a charm! thank You for layout.

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  2. it not working, but it work if connected after other pedal. for example if is connect it after comp, works but with a under volume and warmmy tone, without treble. and if is connected before comp (1st on the chain after guitar) do a breakdown voltage sound. imposible to hear de guitar sound, because guitar sound... not sound hahaha
    the sound when is 1st on the chain is like these... prr prr prr prr nnhh nh nh nh... understand?
    thanks so much for your time!!

    PD: im use J201 and 2N5457 and have the same problem

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  3. Will this work as a stand alone? I'm looking to build a stand alone buffer and I'm torn between this, the cornish, and the stupidly awesome buffer

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    Replies
    1. It will work by itself, but the Stupidly Awesome or Cornish are probably better (I'd lean towards the Stupidly Awesome one personally).

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    2. Out of curiosity why do you prefer that one? I plan on building both the cornifh the stupidly awesome but the more info I have going in the better :)

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    3. It really all comes down to personal preference. You're approaching it the right way by building both and seeing which one you like. I've not built either one, so take what I saw with a grain of salt. I've read that the Cornish buffer colors your tone a little bit. Not necessarily a bad thing, but the Stupidly Awesome buffer is pretty similar to the Klon buffer (which I have built and like and it doesn't color my tone from what I can tell) and so I'm guessing is more likely to be more transparent. Just my 2¢.

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  4. Where I can tweak or put a trimpot to adjust output?
    I'll try this one in front of a Silicon Fuzz Face.

    Thanks!

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    Replies
    1. You could wire a 100k trim pot like a volume pot off the output I guess. (Out to lug 3, lug 2 to out, lug 1 to ground.) This thing should output at about unity though.

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    2. Thanks... I'll see how it goes.

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    3. Does this buffer work to solve the problem with using fuzz face and wah wah?

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  5. Hello, after a long time I return to resume this project.
    I will print the pcb and start over.
    But I have a question. What will happen if I place this circuit inside a volume pedal.
    The order (inside the ordinary volume pedal) Imput VP -> JFET Bufffer -> Potentiometer -> output vp
    Should I try?
    Thanks for everything!

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  6. Gonna try this weekend. wish me luck, lol

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  7. And thanks for that one too! I put one at the input of a deluxe pitch pirate that really needed it. Nice tiny layout!

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  8. i did not find pcb in image library, please help

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  9. Replies
    1. No, el BC 549 es un BJT y este buffer usa JFETs. Probá con J201 o 2N5457. Se pueden conseguir SMD y fabricar un adaptador (para no tener que modificar el layout o recurrir a los encapsulados tradicionales porque vienen truchos)

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  10. what i have to do to turn the phase 180 ° so that i have a buffer that inverts the phase?

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  11. Please give parts/components list...ty

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  12. which resistor must be replaced to get volume above the unit? hey man, very good project. thanks!

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  13. Hello, can this buffer be used in the output of the effect as well? I had a very loud 3pdt pop in a Clone from ISP decimator, and the idea came to me to put this buffer on the input of the isp, but it ended up working perfectly on the output of the effect, now smooth without pop! Thanks

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