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 11, 2015

Dunlop GCB-95 Cry Baby

Here's one of the most classic effects of all time, the Cry Baby wah-wah from Dunlop. The big red thing in the layout is the Fasel inductor, and there's room on the board for a pull down resistor at the input if you need it, I just didn't include it in the drawing. What else is there to say? Just build it!


22 comments:

  1. What is this comp labeled as 500mh? thx!

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  2. has anyone verified or build this? :)

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  3. I hope you considering ibanez wh-10 as next wah pedal project bro.. :-)

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  4. hey man, q2 what transistor is? the image only says q1 - q3
    Thanks :D

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    1. MPSA18s. They're listed just below the underside of the perf. Other high gain NPN silicons should work too (2N5089, BC550C, etc)

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  5. Your layout very very help me. Thanks and I have a question. Can I change pots of wah with LDR? What the LDR value?

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    1. You could replace the pot with a LDR I guess. Value would need to be similar to the pot I would guess. You'll have to do some experimenting there.

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  6. And can I change inductor with another parts? What part is it?

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    1. You're pretty much stuck with an inductor here. Check out the Colorsound Wah that doesn't use an inductor. It's a lot simpler circuit.

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  7. Trying this project, I had all the components here, except for the 3x MPSA18 (that I tried to use 3x BC877 instead, cause i had them here), and still waiting for the Yellow Fasel and another 500mH inductor that i bought. Everything is almost set up, the PCB is done, all the componentes are soldered and I can hear some hissing when i move the 100K pot, so I think this will work. I'll post again when I change the 3x BC877 for 3x MPSA18 and solder the inductor. Things will probably be delivered here in 5/6 days! See ya soon! :D

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  8. Heeeeeey again! I did it and it is working perfectly! :D
    I just had to do some modifications. That 8.2k resistor should be an 82k, and be careful about MPSA18 pins, cause in some manufactures (like the ones i bought haha) Pins 1/2/3 aren't exactly EBC, mine were ECB. And i didn't use the input buffer, for doing the True Bypass mod, i just removed the first transistor (Q1), the 2.2M, 1.8M and 10k(at input buffer) resistors, the 22pF capacitor and the 10nF capacitor (at input buffer). My new input was on "E" leg from Q1, and i used an Yellow Fasel (640mH) as my Inductor.
    Anyway, the only thing i saw as a mistake was the 8.2k resistor that should be an 82k, excpect for that the mods was on my own, not cause it was needed.
    Thank you very much for this layout, i really like the way you made the connection of the 470k resistor to the left side of the inductor without using any jumpers!

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  9. Hey, Could someone help me on the Jacks, 9v and Pot wiring?

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    1. Hi Phillpark. In the General Layout section of this page there's the info you need to do the wiring for the jacks, switch and pot. For example wah 2 and wah 3 are refered to the pin 2 and 3 of the pot.

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  10. This comment has been removed by the author.

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  11. Can i use 2n3904?because i just have it

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  12. Hi there, is it possible to use a different pot for this? I've currently got a 50k ohm linear resistor and was wondering if this would work. Any help would be great

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  13. Hi! I made this project but I have a problem: when the effect is activated, the low signal is working well but the high signal does not work properly, besides the is a drop in volume, any help? Thanks a lot!

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  14. For some reason, I had to switch places between the inductor and the potentiometer? I couldn't get it to work until I put pins two and three of the pot where the inductor goes, and placed the inductor's ends where wah 2 and 3 are. Works fine, now. I kind of discovered this by accident. I had a looper pedal playing through it when I was testing out different inductors, and noticed a difference whenever I'd remove/replace the inductor, but the pot just made the volume go up and down. At first, I tried putting the pot in series with the inductor, which didn't do anything. So, I just randomly decided to put the inductor where the pot goes, and boom—pedal works

    Also, I used 2N 2222 cans, and 5 100mH inductors in series. I also tried it with a single 100mH inductor, which sounded similar, but didn't seem to have the same range. And I reduced the pot value to 50K, which seemed to work better within the ranges of the wah. I found a wah enclosure on thingiverse that I 3d printed, and made some pretty big mods to, but then realized I could put a stereo jack out from where I'd placed pot pins 2 and 3 and use another expression pedal. I also put a 2pdt switch in that inverts pins 1 and three, making the heel/toe movement work in reverse when switched.

    Finally, I put another 2pdt switch in, and built the coloursound wah, and used that switch to go back and forth between wahs with a dual gang 50k pot. Fun times!

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    1. Hey how do you connect the pot and the bypass? Maybe the mistakes that you had is for these connections.
      You can use a transformer with similar 500 mH to use instead a inductor because is the same thing.
      Y will try to see the original pcb for more information. Sorry for my inglish

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  15. Hi folks.

    Is it possible to build this in a fixed way? (like the Q-Zone pedal)

    I want to make this with the "Seagull mod".
    BTW, Does anyone know how to do this?

    Thanks in advance.

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