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.

Wednesday, July 15, 2015

ColorSound Wah-Wah

Here's the ColorSound Wah-Wah. I hadn't laid out a wah before, probably because I haven't built one myself before, and I don't use one much when I play. Anyway, the ColorSound Wah-Wah is pretty simple and sounds very good. What makes it unique is that it doesn't use an inductor like most wah circuits. This might be a good candidate to throw a buffer in front, but it's not necessary. There is a volume pot which you could omit if you want (in which case the Volume 3 pad becomes the output). You could also throw this in a 1590a if you wanted a non-treadle/fixed wah pedal. Or if you're really brave, you could mod a 1590a into a treadle pedal like Thomas Hafemann did.



7 comments:

  1. Effective and simple! thank you! I am about to end, the Overdriver colorsound, hot silicon, Galileo, morpheus distortion,

    I finally the shin ei, nice sound! :D

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    1. It means "thanks bro!" I though that was the unique brazilian visiting your page, i'll try this pedal too.

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  2. Just found this site and have made my first 2 PCBs,many thanks for your efforts, however I have just built this wah as I once borrowed an original and really liked it and have a shell I bought in the 80s that is identical to the colorsound one including the operating lever and it isn't working. I am getting a self oscillation that changes in pitch as the pedal is rocked. I looked at a schematic on line and it doesn't seem to match your layout - can you tell me which schematic you used?
    Thanks

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  3. OK, I have spotted a couple of issues, firstly there should be a 33k resistor in series with the 15nF cap going to ground this is what causes the oscillation since the size of this resistor affects the resonance of the filter. I have put a 47k pot in there and as I turn it towards zero the oscillation starts.
    The other problem is a missing 100n cap which goes from the collector to the 6n8 cap and the 100n output cap - the existing caps need to be disconnected from the collector. Having made the changes the circuit works but I have also changed the input and output caps to 10n as shown elsewhere to brighten it up -may go lower still as it is a little dark. Have also removed the 47k to ground and not used the output pot as unity was not achievable without, may add a 150k as I seem to be getting some distortion now.
    Thanks,
    Dave

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    1. Thanks for catching those mistakes. I must have been asleep when I laid this out. I've updated the layout with the changes. Once you get the distortion issue sorted out, if you still have a volume drop issue (which is pretty common with some of these older effects) you might want to put a booster after this circuit. The LPB-1 would be a good candidate. You could either include the volume pot after it, or use a 100k trimmer to set it to unity.

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  4. I have built it but the wah effect is low, it does not vary so much, what can I do? (I replaced the 2n5088 by bc549, because here is so difficult to find it)

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