No volume boost on GGG Maestro Super Fuzz-Tone (1st post!)

[snushsnush]

Hello everyone!
I'm new to the board and this is my first post. Hurray!
Anyway here's my trouble (following the Debugging FAQ very closely):
GGG Maestro FZ-1S Super Fuzz-Tone
I got the ready-to-solder PCB because this is my first from-scratch project! I also followed the circuit exactly: I had to go out and get an extra 1.5M ohm resistor because the parts list said I only needed one while the schematic called for two.

What it does: The maximum volume is pretty even with the bypassed signal. There are certain contacts that when I touch them the volume increases to a reasonable level. Those contacts change depending on the status of the "fuzz" switch but both seemed to point to the 470k ohm resistor on the bottom left. If I jump it the effected signal is good and loud. So I changed it but it doesn't seem to matter.

I thought about just taking it out and jumping across but the other thing is with the "blend" pot turned all the way to "clean" the clean signal is also equivalent to bypass. No amount of poking around has changed that yet.

I measured the voltages at my battery terminal and for each of the pins on each of the transistors and they are all within acceptable parameters (I'm at work at the moment, but when I measured them I checked them all off) as defined here: http://www.generalguitargadgets.com/index.php?option=content&task=view&id=40&Itemid=93

Alright I think that does it. Thanks a lot in advance!

[snushsnush]

Bump.

Do I smell or something?

[GibsonGM]

Welcome to the forum, Snush!  So, your first big debug...here goes!

First, it's helpful if you post what info you do have in a format such as:
Q1  <<<first transistor
E  < emitter voltage
B  <base voltage
C <collector voltage
And so on for each transistor, left to right....this is in the Debugging thread.

That way we can see what your transistors are doing.  What transistors did you use? Are you sure they are oriented in the right way? (check the data sheet pinout)

"Certain contacts" that you touch doesn't say enough to know what to tell you to do!

If the voltages check out with those posted, the most likely culprits are:
-A solder bridge connecting parts that shouldn't be connected...99% of the time, this is the one
-a part in backwards...transistor or electrolytic cap, maybe?  A pot or part not connected to ground?
-if things change when you move them, a bad pot? A loose connection? A missing ground?
- if you have low volume but good fuzz, maybe one of your feedback resistors isn't connected properly or was switched for the wrong value...same goes for the emitter resistors, which set gain.  Alternatively, your switching might not be connected properly. 

Generally, the debugging thing involves going over your work..and over it, again and again! Even with a magnifying glass and a DMM to test continuity.   A great help is to make an audio probe, listen to the circuit and see what section is buggy...this will narrow your search down considerably!  Probably info on how to make one in Debugging, or search for 'audio probe'. 10 minute build, don't forget the cap to block DC from your amp!

At this point, it could be ANY of the transistors giving you grief.   Make a quick probe, listen to the bases of each stage....the quiet base will tell you the stage before it has a problem.  Remember that going thru tone stacks will make volume lower, but by the last transistor the volume should be up.   Shouldn't be a huge thing, if you used a ready-made PCB.

This should get you started, hope it helps, and post back with more info if not!

~Mike )

[Dan N]

I had one of those and it was not a wall burner as far as volume. Maybe you have a problem, or maybe you have a succesful build...

[smnm]

Do you smell? It's hard to tell, but 45 minutes is not a long time to wait for a reply...

There's a sound sample on Tone Frenzy - does yours sound anythhing like it?
http://www.tonefrenzy.com/sound_files/maestro-fz1s-fuzztone.mp3

plus the GG build instructions doc gives these guide voltage for the transistors

Component Location    Voltage

Q1   Collector   8.8
   Base   2.8
   Emitter   2.2
Q2   Collector   5.2
   Base   1.1
   Emitter   0.5
Q3   Collector   1.0
   Base   0.6
   Emitter   0.02
Q4   Collector   8.6
   Base   0.4
   Emitter   0
Q5   Collector   0
   Base   0
   Emitter   0
Q6   Collector   0
   Base   0
   Emitter   0

[snushsnush]

Thank you all for replying!
Gibson, I think you're right that it might be one of the feedback resistors from that last transistor. I'll check into it.
Man, debugging. The Fun Part.

I've heard people say that other versions of this circuit were very low volume but I was kinda hoping that JD had worked that out. It might just be the way it is. If that's the case then I'll just cross that one 470k resistor and ditch the "blend" pot. It is a fuzz pedal after all.

(smnm: 12hrs,45min. Still not a long time, but I saw all the threads around me getting replies.)

[Dan N]

If that's the case then I'll just cross that one 470k resistor and ditch the "blend" pot. It is a fuzz pedal after all.

I bet it will jump without that resistor!

[snushsnush]

Hopefully! I'll try it out today and totally let you know how it goes.