Fuzz Face Problems

[petemoore]

ep start there...
 If youre measuring voltage between Q1 emittter and ground you WILL read 0.0v should be exactly the same voltage reading as touching the DMM leads together.
 If Emitter is connected to ground then E: IS ground. If you're measurements [reading voltage] are correct there's something wrong with the connection of Q1's emitter to ground !!!

[petemoore]

I've been known to use a wire with alligator clips on it to make connection from emitter to ground.
 First debug task for me is check everything marked ground is at ground using the DMM set to 'beep'.

[saxtim]

sorry - I meant to say I'm using a negative ground!  So the emitter of Q1 is tied not to ground, but to [+9v].  Therefore, I have to read 9volts here, as there isn't anything between the emitter and the 9v supply to take voltage off.

So to restate, I'm using negative ground, not positive.  I should measure +9volts at q1's emitter yes?  (I'm currently measuring 8.95 which is being supplied by a voltage regulator, so that should be correct)

thanks

tim

[petemoore]

Q1 should read Ground as stated on schematics...O.OOOOOv
 positive or negative
 You're measuring between points in the ckt and ground.
 All the points above ground [North on the schem] should read + for neg ground
 Of - for pos ground efkts.
 Gets confusing...as long as you have the black DMM lead to ground and write down your readings, and they all have the same sign [+ or -] the pos and neg don't really matter in this case.
 Figure for regular efkts [neg ground[ ya got a black wire coming from the batt [neg] and a black wire from the DMM to ground...all you readings should be V+
 Pos ground efkts should read v-.
 +9v/ ckt ground/ -9v is for another post...

[Steve C]

sorry - I meant to say I'm using a negative ground!  So the emitter of Q1 is tied not to ground, but to [+9v].

So to restate, I'm using negative ground, not positive.  I should measure +9volts at q1's emitter yes?  (I'm currently measuring 8.95 which is being supplied by a voltage regulator, so that should be correct)

tim

Actually this is the problem,  if you're using PNP Germanium trannys from smallbear, your ground should be + not -   So all of the points on the schematic that are connected to ground should be connected to the + terminal of the battery.  and the only point that should be connected to the - terminal of the battery is the junction where the 33K resister and the 470 ohm (or 330 ohm which ever you used) resistors meet.  

You're measuring 8.95v because you have the - as your ground and the emitter of Q1 connected to + .  Both of these points should be connected to the + .  Then when you make a measurement this point will read 0v.

You shouldn't be reading 8v at the collector of Q1 or the Base of Q1.  They should be much lower.  Hope this helps!

[brett]

Perhaps you should confirm...
I believe that you are building a
-ve to earth
PNP
fuzzface.  Right?  So it is ok for the emitter of q1 to be at the +ve supply rail (~9V).

These posts have become quite confused concerning -ve or +ve to earth and NPN vs PNP.

Anyhow, back to the problems...
One piece of evidence seemed strange to me, and that was that when you disconnected the collector resistor from q2 the voltage drifted up from almost 0V to 9V.  I think that you should check the value of that resistor (R5?).  Is it too small?  Usually, there would be a voltage drop of about 3V to 6V across this resistor.  In you case it seems to be almost 0.  Why?
(ie If q2 is turned on (indicated by a base-emitter difference of about 0.3V) and R5 has an appropriate value (somewhere around 5k to 15k) I think that the voltage at the collector of q2 should be between 3 and 6 volts).