# Twin Face Fuzz: No Sound



## PedalGuy (Apr 7, 2022)

Hello stranger, this is my first PCB build (and my first forum post as well). I've got no idea why this thing isn't working; I have made sure that the switch is working and have measured all of the resistors. I get the correct voltages on R1, R5 and D100. I get my clean guitar signal when the pedal is bypassed (obviously). When I turn it on the LED turns on and I can hear a noise when toggling between Germanium/Silicon but that's it... No guitar, no fuzz, nothing. I have uploaded a few pictures of the PCB for anyone interested. Should you have any ideas or advice for me on this issue, please let me know. If anyone knows how the 4pdt pins are numbered in the schematic, feel free to share your knowledge with me as well (I'm pretty sure I've figured it out already but "pretty sure" isn't good enough for me).


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## Big Monk (Apr 7, 2022)

PedalGuy said:


> Hello stranger, this is my first PCB build (and my first forum post as well). I've got no idea why this thing isn't working; I have made sure that the switch is working and have measured all of the resistors. I get the correct voltages on R1, R5 and D100. I get my clean guitar signal when the pedal is bypassed (obviously). When I turn it on the LED turns on and I can hear a noise when toggling between Germanium/Silicon but that's it... No guitar, no fuzz, nothing. I have uploaded a few pictures of the PCB for anyone interested. Should you have any ideas or advice for me on this issue, please let me know. If anyone knows how the 4pdt pins are numbered in the schematic, feel free to share your knowledge with me as well (I'm pretty sure I've figured it out already but "pretty sure" isn't good enough for me).



Post pictures of the other side of the board


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## Coda (Apr 7, 2022)

Have you biased the transistors? Also, interesting footswitch arrangement.


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## PedalGuy (Apr 7, 2022)

Big Monk said:


> Post pictures of the other side of the board


Here are some more pictures (the white stuff is kitchen paper).


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## Coda (Apr 7, 2022)

Which transistors did you use?


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## Bio77 (Apr 7, 2022)

Your foot switch is not wired correctly.  You should rotate it 180 degrees the input and output wires go into those holes (the one left of the in, and the one right of the out).


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## Coda (Apr 7, 2022)

Bio77 said:


> Your foot switch is not wired correctly.  You should rotate it 180 degrees the input and output wires go into those holes (the one left of the in, and the one right of the out).



The way he has it wired it should work fine. Those two outer holes link to the outer two lugs of the middle row.


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## Big Monk (Apr 7, 2022)

Coda said:


> The way he has it wired it should work fine. Those two outer holes link to the outer two lugs of the middle row.



I think @Bio77 is onto something.

The board connections are correct but the output jack is actually connected to the input side of the breakout and vice versa.

@PedalGuy As a test, plug the pedal in but swap the cables, i.e. input to the output jacks and output to the input.


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## PedalGuy (Apr 7, 2022)

Coda said:


> Have you biased the transistors? Also, interesting footswitch arrangement.


I have now... Works perfectly fine... I haven't played around with the controls yet but at least I heard a guitar signal.


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## Coda (Apr 7, 2022)

Big Monk said:


> The board connections are correct but the output jack is actually connected to the input side of the breakout and vice versa.



He must be left-handed…


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## PedalGuy (Apr 7, 2022)

It stopped working again... I don't know what happened. This is really strange. I did break and repair the toggle switch but I've checked it multiple times and it seems to work fine...


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## PedalGuy (Apr 7, 2022)

Coda said:


> Which transistors did you use?


AC 125, Ac 122 and 2 x BC 108


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## PedalGuy (Apr 7, 2022)

I have taken it out of the enclosure and now it is working again... Weird!


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## Coda (Apr 7, 2022)

PedalGuy said:


> I have taken it out of the enclosure and now it is working again... Weird!



Sounds like something is grounding out against the enclosure. Question: are you plugging into the same jacks in and out of the enclosure? As you have it wired, the jacks are reversed (they actually follow the layout of the original Fuzz Face). It’s fine, as long as you are aware of it…


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## Dr. Satan (Apr 7, 2022)

PedalGuy said:


> I have taken it out of the enclosure and now it is working again... Weird!


It looks like you input and output jacks connections are probably being shorted when you put the cover on. Rotate them slightly so the tabs aren't so close to the opening, the lip on the cover protrudes into the enclosure about 1/8th of an inch.


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## Coda (Apr 7, 2022)

Dr. Satan said:


> It looks like you input and output jacks connections are probably being shorted when you put the cover on. Rotate them slightly so the tabs aren't so close to the opening, the lip on the cover protrudes into the enclosure about 1/8th of an inch.



He’s got them insulated with tape when installed. Somethings shorting, though.


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## PedalGuy (Apr 8, 2022)

I think it's the switch! When I tighten it too much there is a low-pitched pulsating noise, when it's too loose, there is a loud high-pitched squeal on the Silicon side of the fuzz (Germanium is fine). Sometimes both sides work perfectly fine (but it's not reliable). So I'm going to replace the 4pdt switch. Any advice on how to properly remove the switch? It took me 2 hours to remove it the first time I did it...


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## PedalGuy (Apr 8, 2022)

Dr. Satan said:


> It looks like you input and output jacks connections are probably being shorted when you put the cover on. Rotate them slightly so the tabs aren't so close to the opening, the lip on the cover protrudes into the enclosure about 1/8th of an inch.


Possible, but then I wouldn't get any signal when the pedal is bypassed either, which I did.


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## mdc (Apr 8, 2022)

It looks like pin 1 of the PNP bias trim isn't connected.


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## JamieJ (Apr 8, 2022)

mdc said:


> It looks like pin 1 of the PNP bias trim isn't connected.


Good spot. There are a few spots there that need some more solder too.


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## PedalGuy (Apr 7, 2022)

Hello stranger, this is my first PCB build (and my first forum post as well). I've got no idea why this thing isn't working; I have made sure that the switch is working and have measured all of the resistors. I get the correct voltages on R1, R5 and D100. I get my clean guitar signal when the pedal is bypassed (obviously). When I turn it on the LED turns on and I can hear a noise when toggling between Germanium/Silicon but that's it... No guitar, no fuzz, nothing. I have uploaded a few pictures of the PCB for anyone interested. Should you have any ideas or advice for me on this issue, please let me know. If anyone knows how the 4pdt pins are numbered in the schematic, feel free to share your knowledge with me as well (I'm pretty sure I've figured it out already but "pretty sure" isn't good enough for me).


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## Chuck D. Bones (Apr 11, 2022)

Clean the board, inspect everything.


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