PROBLEM with DIY Fuzz Factory. What's my mistake?

[MateuszKaczmarczyk]

Hi,
I have a DIY Fuzz Factory made out of a DIY kit http://www.efekty-diy.pl/pdf/FUZZ%20FACTORY.pdf with mods I found on this forum http://www.diystompboxes.com/smfforum/index.php?topic=59846.0
Enter/exit cups from 10uf to 22uf and 47uf, and a 2,2nf cap under R2 for less highs.

BUT it doesn't work. True Bypass is working, when I turn it on the LED diod is lighting up as it supposed to, but there is no sound. Nothing. Empty. I thing I messed up some wiring at the end. This is how I wired ground and 9V cables

What have I done with this thing for god's sake?
Thanks for any help, cause I'm hopeless.

[GibsonGM]

Without a real schematic it is very hard to give you advice!  Read this and try to fill it out:  http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

It is most likely and error with your switch wiring, or a 'solder bridge' on the PCB, so look VERY VERY closely at both!  Also, very often the DC jack is not connected properly!  Test the voltage right at the board!

Welcome to the forum!   Get started, look at the wiring, fill out the information, and come back - we'll try to help!

[PRR]

> Without a real schematic

In the PDF he linked; snipped here.

This does not show switching or jacks, popular places to make mistakes.

[GibsonGM]

LOL, ya.  I just can't read the pic of the PCB he posted, ha ha!  Gettin' old I suppose.

Most likely there is a wiring error at the switch/jacks, or a solder bridge, but I don't hafta tell you that, Paul.

Here, Mateusz....look at how they wired the 9V jack...look at yours to be sure you did it correctly:  http://www.generalguitargadgets.com/pdf/ggg_sw_3pdt_tb_gi_dcj.pdf

I think perhaps you do not have it wired correctly?  Again, testing for 9V at the board will help.

[MateuszKaczmarczyk]

All that looks extremely confusing, but I will try : ).

[GibsonGM]

#1.....plug it all in, take a meter, and assure that you have 9V going to the board!     If you don't have a meter, borrow or buy one...if you don't know how to use it, come back and ask...

When you are new, trouble shooting is confusing, but it gets MUCH easier in time! 

[antonis]

As far as I can see in your scheme, IN & R1 are connected by the green wire..

If their connection is right (upper leg of anti-pop resistor), it's OK..

If it's on the lower leg of resistor, you've grounded your Inpout.. !!!
(which is most possible considering R1's placement on your PCB..) 

[slashandburn]

Eagle eyes Antonis! 

I'd have thought the input to r1 connection would just be a trace on the PCB, if thats the case just connect the input to the input pad, dont also link the input wire with r1.

If there's no trace, going by the board layout I'd say Antonis is right, you want the other side of the resistor, not the side that (from what we can see) seems to go to ground.

[MateuszKaczmarczyk]

I'm in the middle of borrowing a meter.

About the input into the R1. I think everything is right.

Hope it looks clear.

[slashandburn]

Yeah okay sorry my bad! That part of the board looks like it checks out.

[induction]

Looks like the pad is broken off where you connected R2 to the added 2n2 cap. If so, R2 is no longer connected to the base of Q1.

FWIW, the link to the mod you provided seems to suggest putting that cap across B and C of Q3, not Q1.

[MateuszKaczmarczyk]

It may, but from what I see with my eyes the connection is strong and shiny. The legs from both R2 and the 2,2 cap are strong too. It doesn't move nor nothing. It only looks like that on the photo (if I correctly understand your words). The Q1 mistake MAY BE the reason. I figured out it supposed to be Q1 on my board, because FF has only three transistors, two germanium AC128, and the silicon 2N3904. I thought that It can't be an AC128 because they are only there for the squarewave effect, not the tone (my amateurish me). SOOOO... THIS version of the circuit (which is fan made, and not exactly like the ZVEX's) name Q1 as the oryginal fuzz factory Q3. Reading the mod thread I assumed they are taking about modding the orginal FF, and the original has 2N3904 as the Q3, where on THIS PCB it's Q1. That was my reasoning, but MAYBEEEEE I made a mistake taking a photo of a schematics from the Internet, as a legit one. Maybe the real fuzz factory Q3 IS the AC128, the same as mine.

[induction]

You're probably right. I can see in the photo that what appears to be an unfilled hole in the pcb might just be reflection from the shiny solder joint. Regarding Q1 vs. Q3, the discussion you linked to doesn't specify a schematic, so you may be correct about the numbering as well. Usually we number transistors from input to output, but there's no guarantee without a specific schematic.

It was worth a try. Best of luck.

[antonis]

I can't see color bands on R1 but, perhaps it hasn't the proper value...
(sometimes it's easy to get confused with the multiplier band..)

While you're waiting for a meter, try to desolder and raise up one leg of R1...

[slashandburn]

I'm clutching at straws here but you might also want to check over the trace I've circled.  At a glance it's not obviously scratched deep enough to break the copper trace, but it does appear to have been scratched or scored.



You could also audio probe while you wait for a meter if you're in a rush to get this done.

[MateuszKaczmarczyk]

I will.
BTW R1 is the 1M. As it supposed to be, so that's unfortunately not it.

[antonis]

BTW R1 is the 1M. As it supposed to be, so that's unfortunately not it.

You can still check for some "silly" mistakes, like TOO low R7 value, Q1 Emitter and/or Gate/Volume pots not grounded, "open" C5 e.t.c.

[MateuszKaczmarczyk]

O.K. I did the audio probe test and those are results:
THE RED RINGS indicate pins that have a guitar signal (more, or less fuzzy, but there is one)



Is it me? Or there is something with C5???

[vigilante397]

You have guitar signal on pin 3 of the volume pot but not on pin 2?

[MateuszKaczmarczyk]

Let me check.......
Nope. No sound in pin 2 of RV5. Not even buzzing. Only pin 1 give the signal