# Pyrocumulus Fuzz Schematic



## Flying (Apr 19, 2019)

Hello,

I'm trying to decide on which fuzz to build next, I'm interested in the pyrocumulus fuzz but would like to see a schematic in case it's similar to one I've already built, but the schematic is missing from the build doc.

Any help would be great.


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## HamishR (Apr 20, 2019)

It's a big muff with a bass control.  You won't find a schematic online but there are loads of big muff schematics online.


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## Flying (Apr 20, 2019)

Thank you Hamish.


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## Chuck D. Bones (Apr 26, 2019)

Flying said:


> Hello,
> 
> I'm trying to decide on which fuzz to build next, I'm interested in the pyrocumulus fuzz but would like to see a schematic in case it's similar to one I've already built, but the schematic is missing from the build doc.
> 
> Any help would be great.


If you're looking for a good fuzz, check out the Aldrin (Skreddy Lunar Module).  I built mine as Skreddy Screwdriver.  Same schematic, except it uses a MOSFET for Q1 and a Germanium for Q3.  A few Rs & Cs are slightly different.  Schematics are not hard to find.  It is a fantastic distortion/overdrive/fuzz pedal.  Can even do plain old treble boost with the Pregain & Fuzz controls dialed down.


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## Flying (Apr 26, 2019)

Thanks Chuck, this one is totally new to me, but has already made it to the list, having had a listen to a demo.

I built a Big Muff pedal many years ago, but have never really connected with it, recently I decided to bread board a Fuzz Face out of curiosity and discovered it was a fuzz i enjoyed playing... but that, inevitably, has put me on the a path of discovery into other fuzz pedals.


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## Chuck D. Bones (Apr 26, 2019)

You came to the right place for dirt pedals.  Try feeding your BM with treble booster or EQ pedal so you can reign-in the bass, you might like it better.


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## Chuck D. Bones (May 16, 2019)

Flying said:


> Hello,
> 
> I'm trying to decide on which fuzz to build next, I'm interested in the pyrocumulus fuzz but would like to see a schematic in case it's similar to one I've already built, but the schematic is missing from the build doc.
> 
> Any help would be great.


I too would like to see the schematic.  Does PedalPCB plan on including it in the build docs any time soon?


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## K Pedals (May 18, 2019)

Chuck D. Bones said:


> If you're looking for a good fuzz, check out the Aldrin (Skreddy Lunar Module).  I built mine as Skreddy Screwdriver.  Same schematic, except it uses a MOSFET for Q1 and a Germanium for Q3.  A few Rs & Cs are slightly different.  Schematics are not hard to find.  It is a fantastic distortion/overdrive/fuzz pedal.  Can even do plain old treble boost with the Pregain & Fuzz controls dialed down.


Any chance you could help me out with making one?¿ I’m not very good with schematics...


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## Iceman53 (Dec 23, 2019)

I am troubleshooting a Pyrocumulus build for a friend, as the EQ sections are not working.  Since there is no schematic in the Build Documents, I have a few questions:
How was the circuit board etched without a schematic?
How does one troubleshoot problems without a schematic to follow the signal?
thanks...


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## Chuck D. Bones (Dec 23, 2019)

Did you inspect all of the components and solder joints?


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## Nostradoomus (Dec 23, 2019)

One thing to check...in the baxandall tonestack there is usually a resistor coming from lug 2 of the bass pot to lug 2 of the treble pot...if this resistor is not installed correctly or is way off value you’d definitely have a neutered tone section. Follow the traces on the PCB carefully.




Picture is from the fuzzdog BMP with Bax tonestack here http://pedalparts.co.uk/docs/BaxMuff.pdf, I’m sure the fallout cloud isn’t too far off.


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## Chuck D. Bones (Dec 24, 2019)

That is a James tone control; similar to, but not the same as a Baxandall.  Baxandall tone controls are in a feedback loop and (usually) have symmetric component values.  The EQD Talons (Chela) has a 3-band Baxandall EQ.


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## Iceman53 (Dec 24, 2019)

Thanks for the replies gentlemen.  I will continue to 'poke around' the tone control components. Enjoy your Holiday.


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## Iceman53 (Dec 26, 2019)

Iceman53 said:


> Thanks for the replies gentlemen.  I will continue to 'poke around' the tone control components. Enjoy your Holiday.


Fixed it.  When my friend built the board, he installed spring sockets for the LED resistor so he could change values until he got the intensity that he wanted without re-soldering resistors. That resistor was missing from the board when he gave it to me to troubleshoot.  I remember him saying that it was for the LED, so I didn't give it a second thought.  I'm not sure how he decided that resistor was for the LED, but it wasn't.  It was in the tone control section...causing the tone controls to not work. I plugged in the right value and we now have a fully working Pyrocumulus.     

Thanks again for the suggestions and help


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