Having trouble getting Fuzz Face clone to work

[doschman]

Hi, I'm rather new to circuit building.  I started out by making a few of my pedals I own true bypass and then moved into making simplistic bypass switching pedals and thought I'd try out a fuzz face clone.

I've been using the fuzz face schematic loosely based on Jack Orman's design (http://www.muzique.com/schem/fuzzface.gif) with some other ideas from www.tonepad.com, also.  I've put together the circuit on a bread board and I've checked the circuit flow numerous times to make sure it's right, but I just cannot get the circuit to output anything more than a buzz similiar when you touch the other end of a live instrument jack that is plugged into an amp.  I even printed off the PDF schematic from tonepad.com for the Fuzz Face and copied their layout and I still have no success.

As far as the types of components I'm using:  various 1/4 watt resistors, electrolytic caps and one ceramic cap, two matched AC128 transistors.

If there is anything I can post (e.g. pictures of my breadboard) that would be helpful, please let me know.  Again, I'm new to this.

Any suggestions would be greatly appreciated!

-doschman

[b_rogers]

post your voltages for both trannies c,b,e and supply voltage. make sure you reversed your caps and power supply. a pic of the breadboard would be cool also...

Brent

[doschman]

post your voltages for both trannies c,b,e and supply voltage. make sure you reversed your caps and power supply. a pic of the breadboard would be cool also...

Brent

Brent,

I'll have to ask you your help on how to measure the voltage for those AC128 transistors?  Would I just do a diode test from the base to the collector on each?  As for the supply voltage, it's a 9v battery.  I've switched the caps around having the positive end in the forward part of the circuit and then turned them around to have the negative end in the forward line also and that didnt do me much justice either.  And as far as the caps go, they are all electrolytic caps; maybe those are the right ones to use.

Here's a pic of the breadboard, hopefully it's easy to see: 



Thanks for helping me out.

-Adam Dosch

[alteredsounds]

Hiya,

For the trannie voltages put the negative lead of your meter to the negative part of the board and put the positve lead to each of the legs of the transistor. Triple check the pinouts, this is easy done if you have a hfe option on your meter.  If you have no joy, maybe try a straight forward fuzzface build and try both of the ac128's in it in turn to see which you prefer.

Hope thats some help,  I'm fairly new myself but picked up so much from this site.

Cheers,
Nick,

[doschman]

Nick,

Alright, that's good to know how to measure that.  I'll go over the schematic again this evening and see what I'm doing wrong.  I think that I might be messing up that AC128 darlington pair as far as knowing which leg on the transistor is the base and which is the emitter.  Do you know of any good way to determine that?  I assumed that when looking at the part from the bottom up that the middle was obviously the base, the left was the collector and the right was the emitter.  I couldnt really find a data sheet on it to tell for sure.

I think I might try an easier schematic to dink around with to boost my confidence in actually getting a pedal circuit to work ;-) 

Thanks alot for your input.

-Adam Dosch

[alteredsounds]

Hiya,

Your right about the base but off the top of my head I really cant remember the pinout.  If you have a DMM which will do hfe reading you can pop it in there and you will know you have the pinout right when you get a reading.  I know this is not that important but I find it much easier overall not to socket the trannies when breadboarding.  Just as quick, more flexability and you can see exactly where the pins are going.

Take Care,
Nick,

[petemoore]

  You probably got it right...
  From the info in the threads, I can't quite tell whether you're doing a PNP Pos Gnd schematic for sure.

[petemoore]

  ONe way is to use the DMM's diode checker. And try it between the Base/emitter until you get readings like you would from a regular diode anode/cathode, the mark on the regular diode will follow to it's schematic mark and that should be the same as your transistors diode mark, in the transistor 'circle' on the schematic.
  The other, easier DMM way is if you have a DMM Hfe checker...just set the dial to Hfe, and stick your tranny's leads in every which way until you see a 'typical' number for the Hfe...your transistor pinout is indicated by the permanent print [C/B/E] on the DMM now.
  I start with grab bag junk PNP Si's until the circuit 'fires'.

[doschman]

petemoore,

My fault for the vagueness.  I'm following the PNP Fuzz Face Negative Gnd schematic directly from Tonepad, which is in PDF format by following this link. http://www.tonepad.com/getFileInfo.asp?id=82

It's pretty much an exact copy of the example on Jack Orman's site anout PNP Fuzz Face and using Pos or Neg Grnd http://www.muzique.com/lab/fuzzface.htm.

I'll try out those tips you posted about measuring those transistors.  I do have a much of misc 2N-types lying around.

Thanks for the help so far.

-Adam Dosch

[petemoore]

  There's about one thread a week or so on this subject.
   I'm following the PNP Fuzz Face Negative Gnd schematic
  You can look through and see if there were any resolutions, I think some of them are a page or two down now, I don't remember reading any sure fire fixes.
  I'm more help tho with a FF schematic, NPN for Neg Gnd, and PNP for pos gnd., maybe somebody posted on the other recent thread on this exact subject and I missed it, you'll have to know more than I to understand the schematic you're working from.
  I'd try a Pos Gnd schematic with other ROTM PNP transistors, then the ones you want in your FF after you get it 'firing'...that's just me.
  Hope this helps !!