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SOLVED Pyrocumulus Fuzz

Bobbyd67

Active member
Hi y'all !! I got a pyrocumulus fuzz that ain't working :( I have checked the resistors and reflowed all the pads numerous times ! Gotta clean the back of the pcb real soon... When everything is turn to full I do hear a fuzz from far away but with no sustain. The bass and treble do change the tone and migth be ok but not sure. The sustain knob when turned halfway down kills the little bit of fuzz there is.

Here are the voltages
Ccw. And cw readings are the same
Q1
E:4.38v
B:0.74v
C:0.16v

Q2
E:8.90
B:2.08
C:1.4

Q3
E:5.60
B:0.68
C:0.11

Q4 ccw
E:2-2.5v
B:2.00
C1.35

Cw
E:6.90-7.10
B:1.80
C:1.25

The transistors are from mouser. Tried 2n5088 both directions and pretty much the same thing ..., Here is a pic IMG_20200516_161923.jpgIMG_20200516_161937.jpgmaybe you guys can catch something I missed ! Thanks !!!
 

Bobbyd67

Active member
Thanks so much ! Good catch !... The thing that's scary is that I technically do not own 27r resistors :/ I will have to check my 12k bag ! I took some notes from when I did some mesurements r13 was on it. I gotta check my 2m2 one and the 3 390k ones but I will start by changing r13 tonight !
 
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Bobbyd67

Active member
Well found the culprit.... 18 are accounted for Wich means I got 12 other in various projects :/.... It's time to get in some old projects build docs !!
IMG_20200517_100549.jpg

Well I know what ii am gonna do all night long ... Checking every resistor bag I got !!! 7 years I have been doing this and I am still learning valuable lessons everyday !!!!

Just changed the resistor and it works perfectly !! I got a mini-me chorus from guitarpcb that wasn't working and looking at the schematic I am 75% sure it's that resistor that is screwing up my voltages !
 
Wow... and this is why I read each resistor with a DMM as I install them. I've found a few bad ones, I even found a 1M resistor once that "dissipated"... it would jump to close to the correct value and then the resistance would "drain off" slowly as I held the probes on it. Manufacturing and quality control isn't spot on for these mass-produced components! In your case it was quality control at the packaging stage!! A bag of 27Ohm resistors in a package marked 12K. Ha
 

Bobbyd67

Active member
Well I am happy to say that other pedals that I have made that uses 12k resistors are ok... They were 12k. So it wasn't a error from tayda xD but from me :/ ... The 270r must have come from a old eBay transistor kit that I bought a long ass time ago .... How they got in the tayda bag I have nooooo clue oO. Well now I will have to check every resistor value when populating !!!
 
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