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Monday, January 19, 2015

Fairfield Circuitry Barbershop Overdrive


This one was a request. Two pots onboard and one offboard. The Barbershop Overdrive is a transparent overdrive/booster with medium gain. It has the expected Volume and Drive controls, but also has a Sag control which alters the voltage the pedal is running at. This can change the color and compression of the tone.




UPDATE:

I did a little research, and found out Q4 is just a fancy way of doing polarity protection and can be omitted if you want. Here's a layout without it.



6 comments:

  1. Working!
    Jfets need's to be biased to 6/6,5v at D :-)

    David; possible to add trimmers instead 8k2 and 9k1 resistors?
    Thanks..! as always

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    Replies
    1. Nice! I added trimmers to the 1590A layout I did of this one.

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    2. Saw them! Just don't want to lose the board mounted pots :D
      Thanks again!

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  2. This comment has been removed by the author.

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  3. I have done the layout, works perfectly with SMD J201, biasing is much easier and better, Sag is 10kb working from min to max.

    Through hole J201 doesn't let the Sag work halfway. So annoying to bias as well.

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  4. Here is mine, took me a lot of time biasing the lousy TH J201. Now I've got the SMD, everything works great, bias is around 6-6.5v on Q1 and Q2. Sag with 10kb works fine in the entire sweep.

    shorturl.at/cgmyW
    shorturl.at/jmpB8

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