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.

Thursday, November 9, 2017

Skippy Tremolo

This is Moosapotamus' take on the Vox Repeat Percussion tremolo. The Skippy keeps the character of the original, but with more control while covering a much wider range of tones. There's also the option to use the modern 2N6027 instead of the vintage 2N2646. And you can plug in an expression pedal to control the speed of the effect. I've changed the tone switch to a pot for more fine tuning. More info here.


14 comments:

  1. lines A, B and C are to turn on the expression pedal?

    and how to make that connection on the exit Jack for the expression? would have some diagram

    Thank You...

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    1. Take a look at the schematic and build pics on Moosapotamus' site and I'll bet you can figure it out. ;)

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  2. Thanks for this one, I am planning to build it caus I didn't come to solve ticking problems with EQD hummingbird, personally I think that the solution lies in the PCB design and how compounents are laid and grounded.
    I can't find the PCB pdf in the transfert lib, even in Misc folder, would mind uploding it.
    and millions of thanks in advance

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  3. link below the picture, last sentence
    or go here if you still can find https://www.dropbox.com/s/y9f6zt58yswaiev/Skippy%20Tremolo%20Build%20Doc.pdf?dl=0

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    1. thank you, i have already downloded the build doc and believe it or not, it had only 3 pages (pcb transfert missing) but now it has got four pages (hahahaha :D) anyway thanks a lot ;)

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    2. I added that 4th page and forgot to comment that I'd fixed it! haha

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  4. V E R I F I E D !!
    ok then :°) as promised, I ve built it and if you dont wire the expression pedal jack, you need to jumper B and C pads.
    ... :-) it was ticking like crazy ... but I fixed it by soldering the middle wire of the mode switch in the grounded terminal of R10. after doing that it became dead silent (yessss)
    the tone pote doesn't make much difference. needs some tweaking or going back to the original design, or leave juste one capacitor.

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    1. Thanks for verifying and the build report! Try increasing the value of C1 to 470n or higher to give the Tone pot more range.

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  5. don't forget to tag it as verified !

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  6. Where on Earth do you guys find the unijunction transistor???

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  7. Built this twice with two different board. Tried both 2N6027 and 2N2646 (not at the same time, of course) and tried different transistors for Q1 and Q2. Only thing I got was a boosted clean signal. Any tips?

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    1. Same isssue here. No tremolo at all. Pots are reversed in the layout 3 should be 1.

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  8. I build this but the signal isnt shunting to ground at all. LFO is working but i cant make it work. Any ideas ?

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