Help needed! Tonepad Fuzz Face build

[andopando]

Hello Everyone!

I am a beginner when it comes to building DIY pedals, and as such I thought I would begin with an easy Fuzz Face build. However, it didn't prove as easy as I had hoped, and now I am at a loss in regards what to try next. I have tried building this circuit a couple of times on my breadboard, all with the same result, namely no output what so ever.

Attached you will see my current layout which I have tried to make as close to the circuit diagram as possible. I also tried building this circuit exactly like the PCB board, but that also did not produce any sound!! The Fuzz Face I would like to build is the negative ground one.

Now, a few things to note, is that some of the components I use are not the same as the ones listed on the parts list. Instead of a 33k resistor, I am using a 36k one. And instead of germanium transistors I am using some PNP silicone ones(can't remember the model at the moment). As far as I know, this should only change the output of the circuit. It should not have such a huge impact that the circuit has no output. Or am I wrong? Could these alternative components be the reason why I have no sound? Or is there something fundamentally wrong with my layout that I am missing? I don't know. That is why I am in desperate need of some input. Any help would be much appreciated! Thank you!

[andopando]

Hmmm....

OK. This is rather embarrassing, but I can't seem to find a way to upload personal files to this forum. Could anyone give me any tips on how to do this???

[LucifersTrip]

Hello Everyone!

welcome

The Fuzz Face I would like to build is the negative ground one.

And instead of germanium transistors I am using some PNP silicone ones Could these alternative components be the reason why I have no sound?

you need npn transistors for the negative ground one

best to keep this on the breadboard, take a closeup pic (your attachment didn't show up) and most importantly give voltages described in:

[andopando]

Hello! Thank you very much for your input. I have some NPN germanium transistors. Will try to swap these for the PNP's and see if I get any output.

In the meantime, here is the current layout on my breadboard and the schematic. I will go and get a new meter so that I can also post the voltages later.

[andopando]

http://www.flickr.com/photos/90029134@N04/8182551527/in/photostream/

http://www.flickr.com/photos/90029134@N04/8182572405/in/photostream/

[LucifersTrip]

http://www.flickr.com/photos/90029134@N04/8182551527/in/photostream/

http://www.flickr.com/photos/90029134@N04/8182572405/in/photostream/

breadboard's not the clearest...but on quick scan, looks like 100K is going from b to c instead of b to e

and here's a cleaner schematic (change 330 to 470 for ge)


edit:
https://www.smallbearelec.com/HowTos/BreadboardSiFF/BreadboardSiFF.htm

good voltages for ge:
q1e: 0
q1b: 0.1    
q1c: 0.578  

q2e: 0.447
q2b: 0.578  
q2c: 4.51

[deadastronaut]

this comes up so often i decided to do a diagram....  (NPN)



have fun!.


adjust to taste...


swap the 8.2k for a 10k pot to adjust bias...

[andopando]

Thank you both for your help and excellent info!!

I will re-visit my design on the breadboard and go through the guide to build the cleaner schematic layout you posted. Thanks!

[deadastronaut]

cool. persevere, you'll get it..

[andopando]

Hello

Thank you both again for your input and advises!

I have got the circuit working and have been tweaking it to get the desired sound I want, and I must say it sounds really good now!

The circuit is very nice and quiet, no unwanted humming. Except for the last little turn on the fuzz gain pot. I am using a 1KB logarithmic pot, and I think this might be the reason why suddenly a lot of hiss and humming is introduced on the output when you turn it that last little turn all the way up. Since it is a logarithmic pot, the gain is increased exponentially, which again would mean that that little final turn will produce a huge gain to the circuit output. 

I was wondering if simply switching to a 1KA, linear pot, will solve this issue? Or is there perhaps a mod that can be incorporated? Tried looking around the forum a bit, but could not find exactly what I was looking for.

Any help would be much appreciated as always!

[LucifersTrip]

I was wondering if simply switching to a 1KA, linear pot, will solve this issue?

no, 1K is 1K at 100% no matter what type of pot it is....

you have to expect some hum with a high gain, non gating distortion when fuzz is maxed...you could, of course, put a limiting resistor in there so you can't get max fuzz, but that's sacrilege

there's other taming techniques, but again, sacrilege