The TOFUzz - Octave Down Fuzz

8/28/2014

A new original design named after my favourite food. :)

Silken sounds! Get you chops(sticks) ready! :P

After experimenting with CMOS chips and combinations of fuzz and oscillators I wanted to see if I could achieve something similar with using only regular op amps. This is the result - a fuzz that creates synthy pseudo octave down notes on certain frets on the guitar. Enjoy :)

In the sound sample I'm using the neck pickup with the tone rolled off and i'm playing mostly around the 12th fret. The balance (blend between fuzz/octave down) is at 50%.

I think what pleases me the most with this circuit is the small size. I managed to keep it very simple, just one dual op amp and a handful of components. With that said, I'm already working on a "deluxe" version with a front end gainstage (to keep it from getting too gated) and some filtering (to improve tracking) and that will probably end up twice the size. But for this version I wanted to keep it as barebones as possible.

tofuzz_pcb.pdf
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tofuzz.gif
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14 Comments

Echo

8/30/2014 10:27:51 pm

sounds good!
can't wait for the Deluxe version ;)

Fredrik Lyxzén link

8/31/2014 07:09:06 am

Thanks! :)

Alex

5/7/2016 03:13:48 pm

So, I made this one, and works.
But there's an unbearable humming, do you have any idea what could it be?

5/8/2016 02:32:54 am

Hi Alex,
A loud humming sounds like it could be a grounding issue. Make sure your ground is connected between DC jack negative - output jack - input jack - board. You may have a jold joint in the offboard wiring. Sometimes it helps to just reflow the solder. If it doesn't help, maybe it's the circuit that is oscillating. Check the diode orientation and try replacing the IC (which must be a LM358, a TL072 will oscillate).

I hope that helps
Best regards / Fredrik

5/8/2016 03:55:11 pm

Thanks a lot man, apparently it was a cold soldering.

dale

10/7/2018 08:19:09 am

thanks a bunch for schematics and facs on effects i built the tofo fuzz and put a 100k pot in place of 10k resister from pin 6 to 7 does a lot of cool things .

Terry

2/2/2019 05:14:17 pm

This may be a dumb question but where’s the output? It’s not on your diagram.

2/3/2019 01:05:18 am

Hi Terry,
The output is taken from the volume pot, pin 2.
cheers / Fredrik

2/5/2019 02:44:37 am

Ah great, thank you! Apologies, I’m new to this 😂 - I made the pedal but the led flashes in time with the guitar and there’s a loud buzzing oscillation. Have I maybe got the polarity of the electrolytics wrong? Looks to me like the bottom two have the negative side pointing up and the other one has it the other way around?

2/5/2019 09:36:55 am

You are correct about the electrolytic orientations. A loud buzzing sound usually means a grounding issue. Make sure that your ground points are all connected: input and output jack sleeve, DC jack negative lug and the board GND.

nico

10/24/2019 09:48:10 am

buenas hice este diseño y funciona bien pero al terminar de pulsar una nota suena una nota decallendo como un boooooooooooouuuuuuuuu. largo aun no encuentro que sera . puse un pote de 250 k en lugar de 200 k poruqe no consegui. sabes que podria ser??

MrJosh69

4/4/2020 07:20:04 am

Tiene pinta de que has elegido la capacitancia de algun condensador demasiado grande, o te has equivocado en alguna resistencia. fijate bien en que algunos son nanoFaradios y otros MicroFaradios

casino utan licens link

1/31/2022 09:44:58 pm

His team does a top-notch job, in a reasonable amount of time

mjv913

2/26/2022 08:41:20 pm

Hey! Built it, love it! Way more useful than i was expecting it to be. Going to have a tinker and see if i can make it a little less gated.

Anyway heres some demos:
Short: https://youtube.com/shirts/wcEvPHgKAkU?feature=share

Long: https://youtu.be/xTWdqmkmv7Q

The TOFUzz - Octave Down Fuzz

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