Fuzz Face sounds...dead

[spargo]

I'm bread boarding a silicon fuzz face and trying a variety of transistors.  It sounds dead.  With the volume and fuzz cranked I just barely get a weak flail of distortion - it sounds like roadkill.  Back off a bit on the fuzz and it turns pretty clean, but still weaker.

I've triple checked the schematic and the transistor pinouts.  Gains are all below 150hfe.  Voltages are:

Q1
C: 1.6v
B: .6v
E: 0v

Q2
C: 4.5v
B: 1.6v
E: 1v

[Joe Hart]

Those look very close the the "ideal" numbers. Hmmm. Did you check all your solder joints?
-Joe Hart

[MrTonesNZ]

Sounds to me like you and I have the exact same problem. See my thread :
http://www.diystompboxes.com/smfforum/index.php?topic=93216.0

Do me a favor, is your problem fixed when you put something infront of it in the chain? I don't know if all pedals do the job, but so far with me, the problem gets fixed when i put a boss od, or my whammy in front of it. Does't even need turning on.

Try that and let me know, we may be in the same boat..

[spargo]

Those look very close the the "ideal" numbers. Hmmm. Did you check all your solder joints?
-Joe Hart

It's on a breadboard...

Sounds to me like you and I have the exact same problem. See my thread :
http://www.diystompboxes.com/smfforum/index.php?topic=93216.0

Do me a favor, is your problem fixed when you put something infront of it in the chain? I don't know if all pedals do the job, but so far with me, the problem gets fixed when i put a boss od, or my whammy in front of it. Does't even need turning on.

Try that and let me know, we may be in the same boat..

I'll have to check and get back to you.  If that's the case, it is probably due to some kind of buffer in those pedals.  But your voltages are very different from mine - they are very high.

[MrTonesNZ]

I'll have to check and get back to you.  If that's the case, it is probably due to some kind of buffer in those pedals.  But your voltages are very different from mine - they are very high.
[/quote]


No if you read on you'll see i was measuring wrong lol. Yea i assume the same thing regarding the buffer, in any case, it sounds fantastic this way. I figure if you get the same result i do, then we may have the same circuit problem

[Joe Hart]

Have you tried a different guitar? You shouldn't need a buffer to make the Fuzz Face work. Are you both going from guitar to Fuzz Face to amp or is there anything else in the chain?
-Joe Hart

[LucifersTrip]

since your voltages are correct, I'm going to guess there's a bad connection or mis-wiring in the off-board wiring...or possibly a bad connection near the in or output

did you double-check your jack & pot hookups?

[MrTonesNZ]

Have you tried a different guitar? You shouldn't need a buffer to make the Fuzz Face work. Are you both going from guitar to Fuzz Face to amp or is there anything else in the chain?
-Joe Hart

I know I am. And yea, it shouldn't need a buffer, but mine seems to

[Govmnt_Lacky]

Volume pot wired backwards or wrong taper  

EDIT: Sorry! Posted in wrong thread 

[MrTonesNZ]

How're you getting on?

[spargo]

Will be working on it over the next few hours and let you know.

The confusing thing for me was I had one bread boarded a few weeks ago with a couple mods and it was rockin'.  Then for some reason (can't remember why) I decided to start over, and now it won't work at all... I mean, it's not like it's a complicated circuit.

[spargo]

Latest report:

- Tried removing the power filtering section that I added: no change.
- Replaced all the caps: no change.
- Replaced the pots: no change.
- Shortened I/O wires on the breadboard and separated them more from one another: no change.

If the fuzz pot is in about the first 80% of rotation there is little to no volume (with the volume at max).  The last 20 percent the volume jumps up to be very audible, but there is zero fuzz when using a bridge humbucker, and very little fuzz when using a neck humbucker.

[MrTonesNZ]

Latest report:

- Tried removing the power filtering section that I added: no change.
- Replaced all the caps: no change.
- Replaced the pots: no change.
- Shortened I/O wires on the breadboard and separated them more from one another: no change.

If the fuzz pot is in about the first 80% of rotation there is little to no volume (with the volume at max).  The last 20 percent the volume jumps up to be very audible, but there is zero fuzz when using a bridge humbucker, and very little fuzz when using a neck humbucker.

I have similar results. Giving mine a rest. Are you 100% sure the transistors are orientated correctly? Thats what people keep suggesting to me, and i'm starting to second guess myself. The other thing, maybe you managed to fry your transistors when poking arround. I did that a copuple of weeks ago, don't quite get how it happened but it did. Was using silcon too.

Did you try plugging another pedal in front of it?

[spargo]

No pedal in front of it yet, but I've tried lots of transistors so if that's the problem I must have fried them all.    Is there a good test for that?  I also put them in backwards, and that gives me no sound at all.

I put a 10k trimpot in for the resistor to Q2 C, which varies the voltage from about 3.9v to 9v.  It does almost nothing now.  I thought it used to do something... Setting it to its lowest value (3.9v) gives the best results, which is the slightest bit of fuzz.

[MrTonesNZ]

hmm, thats weird. I've been doing the same, but mine likes it round 6. What voltages are you getting now?

[petemoore]

  It doesn't look complicated but it is 'twisty', crossing wires and such, count the number of connections at each node at schematic and build, make sure the same number applies to both, then check values and polarities as related to that node, then the next node.
   ...Kind of like the 'long way around the circle' but it does give very high resolution to the circuit.
   Might seem like a time-killer but so is repeating the same 'didn't yet debug routine'.

[MrTonesNZ]

You 100% that the transistors are in the right way? Mine wern't

[spargo]

Double checked the entire layout again. No visible problems.

Quadruple checked the transistor pinouts against their data sheets again. They're in correctly and connected to everything they should be.  I'm at a total loss...I guess I'll tear everything off the breadboard, start over and hope for the best?

I'll remind you I'm getting the correct voltages everywhere...

[spargo]

Also, there is now oddly a loud, odd type of hum (not a normal hum) that comes if the volume pot is in specific places.  It's greatly increased when you touch the guitar strings.

[spargo]

Just tore it all off the breadboard and redid everything.  Exact same problems.  Excellent voltages, almost no fuzz with the fuzz knob at full.  Back the fuzz knob off from full just slightly and everything gets muted.