My univox super fuzz pedal kit won't work

Started by snow123, March 09, 2021, 04:57:33 PM

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snow123

ok i dont know if my audio probe was doing anything but while i was testing stuff, the signal just popped, and cut in and out depending on what parts of the circuit and stuff i touched and depending on where i moved things i guess. and now my ears hurt 'cause of the loud popping noises

snow123

and i dont have any alligator clips so i tried just soldering a 10nf ceramic cap to a metal alligator clip (that came off of some helping hand thingys) and a breadboard jumper wire to the capacitor

andy-h-h

Test your audio probe on something that you know works.  Photos of the probe set-up?

snow123

Well I just built a new one and here it is






andy-h-h

So yellow to ground and red to test.  Looks fine to me.

snow123

ok, when i put the probe on the tip of the input jack the dry signal gets through

snow123

and when i probe r3, r5, and r2 my standard dry signal gets through, but when i probe r6 and r7 the gain goes up alot.

snow123

and probing r17 gets most of the effect through, i get nothing on r11, r18, and r13, i get a thin sounding signal on r8, and i just get a heavy gain boost on r16

snow123

my dry signal gets through on only 1 side of c2. dry signal gets through on c1. c6, c5, c9, and c7 get a minor super fuzz sound, c8 gets most of the effect. c11 got a very loud super fuzz sound through. c10 is very low volume dry signal, and c14 is a very low volume wet signal. and i get nothing when probing c17 and c16.

snow123

c13 on one side i get a very loud super fuzz sound but on the other side of it is very low volume

snow123

Q1
C= very high gain dry signal
B= very low volume dry signal
E= standard dry signal

Q2
C= nothing
B= higher gain dry signal
E= a little bit of a high octave dry signal

Q3
C= lower gain octave fuzz
B= slightly higher octave dry sig
E= half of the effect

Q4
C= low volume effect
B= lower treble octave fuzz
E= full volume octave fuzz

Q5
C= same as q4
B= same as q4
E= same as q4

Q6
C= nothing
B= low volume super fuzz
E= low volume super fuzz

snow123


snow123

i got the full effect on d1's cathode and d2's anode but not on the other sides

snow123

low gain dry gets through on r1, i get something on 1 side of r33 and nothing on the other side, i get nothing on 1 side of c4 and nothing on the other, i get the full effect on c12, i get the full effect on r24 and r25. i get nothing from r32, r21 makes a low volume effect, probing 1 side of r29 and r31 make a popping sound and the other side just made a low volume octave fuzz go through. i got nothing out of G, 0, 9v, and L and got something from b2, b3, t3, e2, and I. and i got something out of 1 side of r14, r15, and r19 and got nothing out of the other side, and got something from both sides of r20.

snow123

FYI while i was moving things around and trying to probe things on the TOP of the PCB the LED turned on and off rapidly and made VERY LOUD popping noises. my ears hurt now

snow123


andy-h-h

#196
Quote from: snow123 on May 03, 2021, 06:41:06 PM
FYI while i was moving things around and trying to probe things on the TOP of the PCB the LED turned on and off rapidly and made VERY LOUD popping noises. my ears hurt now

This sounds like you have an intermittent short somewhere - which is the worst kind of short....   


andy-h-h

Quote from: snow123 on May 03, 2021, 06:19:42 PM
i got the full effect on d1's cathode and d2's anode but not on the other sides

The diodes go to ground - this is called hard clipping, and there should not be any signal on one side (the ground side).   That's normal. 

andy-h-h

#198
Post removed - I'm hitting eject on this one.   :icon_confused:

andy-h-h

Quote from: snow123 on May 03, 2021, 07:52:43 PM
that might be it for the pcb tho

Yeah - how long do you want to keep working on this?   If you can afford to start fresh, start fresh.  I would order two kits, one being really easy to have a win and get some skills and confidence.   The other being another Super Fuzz.