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.

Tuesday, August 4, 2015

Dunlop Fuzz Face - Eric Johnson

Here's a layout for the Eric Johnson Fuzz Face. Had someone ask if they could build it on the basic Fuzz Face layout from last year. Since there's a few extra components in the EJ version, I thought I'd make a specific layout for it. Should still fit in a 1590a though. Q1 is a BC183 (hfe ~250), and Q2 is a BC183C (hfe ~650). Use the trimmer to bias Q2 to 3v.



9 comments:

  1. Hi man, the diode protection this backwards in the layout.wrong polarity.And the 1uf cap in others layout is NP, not electrolitic.Tomorrow say if it works.thanks!

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  2. Replies
    1. Thanks for verifying. Fixed the diode polarity. The polarized cap shouldn't matter much at all tonally. And it's oriented the right way if you do use a polarized cap. I'm just assuming most people have more polarized electros than non-polarized ones.

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  3. I'm new to this forum
    I built this fuzz, when I plug it in , bypass works fine but when I click on effect I get a drop in volume and barely any fuzz .. can only get trimpot voltage down to 4.75v
    Can anyone suggest what may be going wrong.
    I'm a complete Nube

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    Replies
    1. Trying using a larger value trimmer. You may also need to adjust the 39k resistor going to the collector of Q1/base of Q2.

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  4. Yeah cheers I fixed that problem. Q1 transistor needed to be
    Rotated..
    now everything working however I’m now getting a
    Reading of 8+ v at Q2 c .. I did adjust the trimmer to 3v
    Earlier. I’ve only changed the fuzz pot ( only have 10kB )
    And now can only get 8+v .. what have I done ???
    It all still works I just want correct voltages..
    Q1 - 2N3904
    Q2- 2N5089
    Awesome site
    Thanks for your help

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    Replies
    1. I suspect using the wrong pot value is throwing your voltages off. If it works and sounds good why worry about the voltages?

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