FUZZ FACE "Boutique" 1969 diagram changes?

[half_smith]

Hey gang! I found this FUZZ FACE diagram floating around,
It's a NEGATIVE GND PNP version that apparently used to be available on GGG until they discontinued it because it was giving so many people problems.
Well, I have a bunch of PNP GE and want to try it anyway.

Anyone verify this diagram?

Someone on the Strat_Talk forum changed the jumper on column15 to rows 2,3 (instead of 3,4)?
I feel like 22uf should be moved down a row?


Thanks!

[half_smith]

I'm so confused by the NPN/PNP +GND/-GND stuff!

I built a vero with this exact diagram and my voltage on Q1E is 9V, I mean, it's directly jumpered to the 9v rail.
known voltages for Q1 should be >1v

I've gone and tried swapping the rails (so the 9v is dropped by the 33k) this gives me 0v on Q1E and a "lower" Q1C but still like 8V

What gives?

[antonis]

I built a vero with this exact diagram and my voltage on Q1E is 9V, I mean, it's directly jumpered to the 9v rail.
known voltages for Q1 should be >1v

http://www.muzique.com/lab/fuzzface.htm

It's plain enough, if you consider current flow from Emitter to Collector for p-n-ps and form Collector to Emitter for n-p-ns..
Current flows (conventionally) from a higher voltage level to a lower one..
(EMF from +9V to +5V is absolutely the same with the one from 0V to -4V or from -5V to -9V)

[duck_arse]

as antonis says - name your ground, either positive or negative. connect all your audio/signal grounds and all your supply grounds together.  connect the black probe to ground. leave it there. take measures around the circuit with the red probe. IF the meter reads minus volts, WRITE THAT DOWN. that's the voltage relative to ground, which is how we know what you are doing.

[half_smith]

well guys, I'm learning the hard way again. But I will eventually get it.

In the meantime, I've gone nuclear and pulled everything off the board - why not breadboard first you ask? BECAUSE THAT's FOR SMART PATIENT PEOPLE!

I'm switching to this diagram and gonna have better luck this time around...

Can anyone confirm this layout, or see any corrections?
If it works I will try adding a pull down resistor, filter caps, "contour" and "bias" trim pots - which I hope will only help my biasing without making problems-

[Locrian99]

The pot labeled bias there would be what a bias trim pot would do.   So no reason to try to add one.   I'd watch out on that layout as it's got the transistor pins twisted as well. 

[antonis]

Don't get me wrong but I'd suggest to start building a Si n-p-n Fuzz Face, then pass to Si p-n-p one, then pass to Ge p-n-p one and THEN pass to Ge p-n-p with bipolar supply..

P.S.1
A Fuzz Face can be "noisy" enough by itself so by also using a switched-capacitor voltage converter (like MAX1044) might drive you nuts..

P.S.2 (IMHO)
FFs are FFs mainly due to their brutal simplicity..
By adding various "improvements"/"refinements" you might result into some kind of sissy ODs..

[half_smith]

P.S.2 (IMHO)
FFs are FFs mainly due to their brutal simplicity..
By adding various "improvements"/"refinements" you might result into some kind of sissy ODs..

I can see what you mean. I hate 1044's always give me problems, that's why I have a bunch sitting around, because I forgot that I always end up taking them out.
The only refinements I'm interested in is more biasing control, because I only have access to random Ge Transistors so I gotta make them work. Hoping to get one good circuit for my board

I built a Si ColorSound no problems, just kinda boring - not enough tweakability...

GE Fuzz Face is my goal, and as you know Antonis, I am very slow and yet determined!

[Rob Strand]

I built a Si ColorSound no problems, just kinda boring - not enough tweakability...

GE Fuzz Face is my goal, and as you know Antonis, I am very slow and yet determined!

Try Q1 = silicon and Q2 = Germanium.   Then perhaps tweak the Q2 resistor to get the sound you like (can start with Q2 collector voltage at 4.5V).  This configuration is easy to get to work.   Maybe use this build as a stepping stone.

[duck_arse]

don't build anything that you don't have a complete correct circuit diagram for, especially if it has an added charge pump, even if it is only a fuzzface.