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.

Saturday, June 6, 2015

One-Knob Fat Fuzz

Here's another quicky for your weekend. This is based on Tim Escobedo's LoFoMoFo, but tweaked for more bass frequencies. This circuit was actually my first build and it sounds great. Although, I made the n00b mistake of using a 10n cap on the input instead of the 100n because I misread the capacitor code. So I guess I should say it sounds good with a 10n input cap. Can't really speak to the stock sound, but it's apparently very fat. Should fit easily in a 1590a.


23 comments:

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    1. I haven't tried it on bass, but I don't see why it wouldn't work just fine on it.

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  2. Just little n00b question bro, why the volume doesnt mute when the knob is turn all the way down?
    Its just like it in nature?
    Great fuzz for bass anyway, fat and growly.
    Cheers mate.

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    1. It should mute when it's turned all the way down. Lug 1 of the volume pot goes to ground. You could have a bad pot, or maybe you wired it incorrectly?

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  3. If I want to control the "fuzz gain"? Just change the 100k resistor in the base of transistor to pot? Or the 100k resistor in the collector? Sorry for bad english

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    1. You could try making the 100k resistor from 9v to the collector a pot, but a more effective gain control might be putting a pot before the input. In wire to lug 3 and lugs 2-1 go to the input pad of the circuit board.

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  4. Thanks bro.., built this for my bass and i like the sound.
    I built with the gain control as you said

    "... but a more effective gain control might be putting a pot before the input. In wire to lug 3 and lugs 2-1 go to the input pad of the circuit board."

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  5. This sounds good qith a big muff tone stack as well

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  6. Hi, i'm from Argentina and this one is my first build, but i have a problem, when i play a string, a fart-like noise come out of the speaker for a few seconds and then it disappears (with the pedal connected) and i don't know why, it should work, maybe a bad diode or transistor?. thanks

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    1. Sounds like it could be mis-biased. Make sure you've got a 100k resistor going from the power line to the collector. Or that value may need to be adjusted. If so, grab a 250k or 500k potentiometer and wire lugs 1 and 2 to either side of where that 100k resistor would go. Adjust the pot till it sounds right. Then measure the resistance across those two lugs of the pot and replace it with a similar value resistor. Good luck

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    2. i've made the 500k pot wiring but it didn't work, it changes a little bit but almost the same sound as before, i think that the pedal is working but with no sustain at all, i hit the string, the sound comes out and immediately stops tracking the note, and i have to hit the string very hard to make the pedal sound that way, if i strum normally it's almost inaudible, i'm currently using used capacitors, and a 1n4007 diode, maybe it's that?, thanks in advance :)

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    3. That diode shouldn't matter. Double check the pinout of your transistor and double check the values.

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  7. Finally! it's working perfect, i made a n00b mistake (connected the 9v the wrong way. Positive where the negative goes xd). Thanks for the fast response i really like the sound of this tiny pedal, very big sound, now it's time to keep trying new pedals ;), again thanks.

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  9. I checked all and everything is connected good, but it makes fart like distortion, very annoying tone..not sure is it bcoz I use S8050 transistor (npn ebc), it's even higher hfe than original, but who knows..I'm not sure where to connect pot at input, is it instead of 1m resistor or before it, and how exactly to connect it anyway, it's not clear for me?

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    1. It could be the transistor hfe. To connect a pot as a pre/gain control, wire the input to lug 3, 2 to the input pad on the board, and 1 to ground. And you can remove the 1M pulldown resistor at input.

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  10. I wonder is it possible that problem is in wrong resistors wattage, for example, if circuit requires 1 or 2W res. and I maybe use just 1/4W ??

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    1. Wattage shouldn't matter. 1/4 watt is sufficient for everything on the blog unless otherwise noted.

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  11. I solve it, not sure what exactly was problem, because I replaced transistor with better onr with very high hfe, and also put that pot at input, and now is very decent sound, especially is awesome if I put booster in front of it, I cannot resist not to use them in front of anything, thank you :-)

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  12. Hi, i made this one and i want to add a simple tone pots ... how can i do ? i tried a pot with 0.0047uf cap on the lug 2 of volume pot but don't work ... (Sorry for my bad english )

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  13. Hi. I did this, but soud like overdrive. What's hfe for Q1?

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