My univox super fuzz pedal kit won't work

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

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eh la bas ma

#80
Did you do something about the possible short I saw on your picture ?

If so, it's time for voltage readings :

"Now, using the original schematic as a reference for which part is which (that is, which transistor is Q1, Q2, etc. and which IC is IC1, IC2, C1, and so on) measure and list the voltage on each pin of every transistor and IC. Just keep the black lead on ground, and touch the pointed end of the red probe to each one in turn. Report the voltages as follows:

Q1
C =
B =
E =

Q2
C=
B=
E= "
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123


snow123

#82
so do i have to solder on the top to test the ground?

snow123

Quote from: eh là bas ma on April 26, 2021, 09:26:04 PM
Did you do something about the possible short I saw on your picture ?

If so, it's time for voltage readings :

"Now, using the original schematic as a reference for which part is which (that is, which transistor is Q1, Q2, etc. and which IC is IC1, IC2, C1, and so on) measure and list the voltage on each pin of every transistor and IC. Just keep the black lead on ground, and touch the pointed end of the red probe to each one in turn. Report the voltages as follows:

Q1
C = 001
B = 001
E = 001

Q2
C= 001
B= 001
E= 001

andy-h-h

#84

eh la bas ma

Quote from: snow123 on April 26, 2021, 10:21:26 PM
so do i have to solder on the top to test the ground?

You don't need to solder anything to take measurements with the multimeter.
You don't need to test the ground : the black lead is always connected to ground, any ground, like jack's GND or DC power jack's GND, without soldering it. The red lead is in contact with one transistor's leg at a time, in order to read its voltage with the multimeter. The circuit should be connected to 9V power supply, to have some voltage in the transistors.

"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123


Q1
C = .947
B = .932
E = .978

Q2
C= .936
B= .937
E= .940

snow123

and some of my readings were quite inconsistent so i checked continuity and the probes are grounded to the pcb

eh la bas ma

#88
I would check if there is 9V coming on the board (black lead on ground and red on 9V pad) :


I don't understand why you left C3 and C15 empty. Your schematics don't mention anything about it.

If you think it's ok to leave them empty, you can try to put a jumper at C3 (connect both empty pads with a short wire that you can easily remove), if there is no change, try to put one at C15, if still nothing changes, try to put jumpers at both C3 and C15.

If it's still doesn't work, I would try to remove Q1 and see if there is some voltage at these pads. If there is, try to turn it around, in case it is oriented the wrong way.

Edit : to test voltage you need to set your multimeter on position marked "6" on this picture (DC voltage)


"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123

#89
GGG said that c3 and c15 arent needed (on the mod info page for the kit:http://generalguitargadgets.com/pdf/ggg_superfuzz_mods.pdfhttp://generalguitargadgets.com/pdf/ggg_superfuzz_mods.pdf) and i didnt have the right cap for c3 so i just removed c15 aswell.

eh la bas ma

#90
Quote from: snow123 on April 27, 2021, 02:59:18 PM
GGG said that c3 and c15 arent needed (on the mod info page for the kit:http://generalguitargadgets.com/pdf/ggg_superfuzz_mods.pdfhttp://generalguitargadgets.com/pdf/ggg_superfuzz_mods.pdf) and i didnt have the right cap for c3 so i just removed c15 aswell.

Sorry but your link gives me a "No Results Found"

Edit: I've found this : http://generalguitargadgets.com/pdf/ggg_superfuzz_mods.pdf

Looks like you are right, and there is no jumper on their picture.
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

antonis

#91
C15 is a Q6 Collector-Base feedback cap (Miller) so better left "open" than shorted via jumper.. :icon_wink:

http://generalguitargadgets.com/pdf/ggg_superfuzz_sc.pdf
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

eh la bas ma

#92
I think i might have spotted something : on the picture in exemple here : http://generalguitargadgets.com/pdf/ggg_superfuzz_mods.pdf

there is a jumper near D2 (marked "a / b "). Looks like on your build these pads are empty... I'm not quite sure about this but it might worth the try.

Edit : I don't see these mysterious pads on the picture shown here, but there is a chart of voltages that you can use, I guess.

http://generalguitargadgets.com/pdf/ggg_superfuzz_instruct.pdf
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123

Quote from: eh là bas ma on April 27, 2021, 03:45:11 PM
I think i might have spotted something : on the picture in exemple here : http://generalguitargadgets.com/pdf/ggg_superfuzz_mods.pdf

there is a jumper near D2 (marked "a / b "). Looks like on your build these pads are empty... I'm not quite sure about this but it might worth the try.
nah i do have the jumper there, its just kinda hard to see


eh la bas ma

Looking at your schematics, at your build and at this picture, considering that you said in reply #68 that you are using p2n2222a :



schems:
http://generalguitargadgets.com/pdf/ggg_superfuzz_lo_mods.pdf





I think your transistors are the wrong  way around...
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123

Quote from: eh là bas ma on April 27, 2021, 05:05:14 PM
Looking at your schematics, at your build and at this picture, considering that you said in reply #68 that you are using p2n2222a :



schems:
http://generalguitargadgets.com/pdf/ggg_superfuzz_lo_mods.pdf





I think your transistors are the wrong  way around...

the kit came with p2n2222a's but im using regular 2n2222a's.

eh la bas ma

#96
Looks like the pcb layout isn't the same as the schematics from your first post. One way to make sure they are oriented right is to test Q1 :

Q1's Collector should ring with R4 with your multimeter on continuity mod. If it does, then there is no doubt about transistors orientation anymore.
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123


eh la bas ma

#98
Do you read 9V with your multimeter on the pcb 9V pad ?
"One Cannot derogate, by particular conventions, from the Laws which relate to public Order and good Morals." Article 6 of the Civil Code.
"We must not confuse what we are and what society has made of us." Theodor W. Adorno.

snow123

i dont think im getting 9v on the Multimeter but the multimeter does make the led and stuff flicker