Please help with Axis Face problem

Started by Greg M., May 17, 2008, 10:09:07 PM

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Greg M.

I've made the Axis Face silicon fuzz from fuzz central and can't get it to work.  Using this layout http://fuzzcentral.ssguitar.com/axisface/axisfacesi3layout.gif I'm getting no reading from #1 or #2.  On one side of the 1M resistor and 0.22uF cap, I get a reading, but then nothing on the other side, which lead to the Bias pot lugs 2 and 1. 

Here are some other readings from a 9.08v battery to go on:

Q1 E=1.36 B=2.03 C=2.94
Q2 E=2.35 B=2.95 C=2.43

From the pcb layout, I have these readings:
1=zilch
2=zilch
3=2.5
4=1.5 (yes, this is the ground.  Should be zero, right?)
5=9.0
6=1.5
7=2.5

Thanks for any advice you can give me.  This thing really has me at a loss.

Pushtone

Quote from: Greg M. on May 17, 2008, 10:09:07 PM

Here are some other readings from a 9.08v battery to go on:

Q1 E=1.36 B=2.03 C=2.94
Q2 E=2.35 B=2.95 C=2.43



These don't look at all right. I'll go meter mine for ya, gimme a few.
In the mean time you should check the pin outs of the transistors your using against the layout.
I think you have the transistor in wrong.

The layout offers four pads for the transistors to accommodate different pin outs.
The flexibility of the layout also creates a potential pothole.
Make sure you know what pin out your transistors are and that its in the right three pads on the layout.



Quote from: Greg M. on May 17, 2008, 10:09:07 PM

From the pcb layout, I have these readings:
1=zilch
2=zilch
3=2.5
4=1.5 (yes, this is the ground.  Should be zero, right?)
5=9.0
6=1.5
7=2.5


Other than #4 & 5 these are not useful points to meter.

The bias voltage is metered at the collector of Q2.




It's time to buy a gun. That's what I've been thinking.
Maybe I can afford one, if I do a little less drinking. - Fred Eaglesmith

Greg M.

Thanks for the reply Dave.  I will check those pinouts again.

Something I forgot to mention:  when I pushed Q1 into the socket, my finger was on top of it and it squealed.  Is this normal or a sign of something specific like the wrong pinout?

petemoore

my finger was on top of it and it squealed.  Is this normal or a sign of something specific like the wrong pinout?
  'squeal' = oscillation, and the FF is capable of oscillating, high gain or some wierd thing can have it producing osci-type tones.
Convention creates following, following creates convention.

Greg M.

I checked the pinouts again, and unfortunately they're right.  All three legs of both Q1 and Q2 basically read full battery power or close to it.  Obviously something is very wrong. 

Shouldn't all ground points have no reading?  I'm pretty sure that's supposed to be the case, but I'm getting readings at the grounds.  Dang, this is a headache. :icon_mad: