ge fuzz face problems

[ninjadave7]

Hey all,
I did a vero version of the old fuzz face based on layouts in the gallery, but altered according to amz to be negative ground so I could run it on pedal power.  My trouble is that the volume amplifies just fine, but the fuzz pot does nothing...

Voltages I'm getting are as follows, when on a 1-Spot:
Q1 -
E - 9.4V
B - 4.9V
C - 4.9V

Q2 -
E - 8.9V
B - 4.9V
C - 4.83V

Any suggestions?

[Govmnt_Lacky]

Link to layout?

[Jaicen_solo]

Check the cap to ground from Q2. Did you reverse it for NPN ground?

[LucifersTrip]

Voltages I'm getting are as follows, when on a 1-Spot:
Q1 -
E - 9.4V
B - 4.9V
C - 4.9V

Q2 -
E - 8.9V
B - 4.9V
C - 4.83V

Any suggestions?

you must have something reversed. shouldn't Q1E still be 0v?

[ninjadave7]

http://www.aronnelson.com/gallery/main.php/v/Renegadrian/fuzz+face+7+buchi_+1_1.gif.html

That's the link to the layout.  I know it's for silicon, but it works with all the Ge FuzzFace schematics I could find, including the one on AMZ.  I did switch both caps, as per the schematic on AMZ for switching the to negative ground.  I double, triple, quadruple checked my AC127 pinouts too.

[ninjadave7]

I don't know what i could have reversed, there's only 9 parts, I must be missing something so simple it's stupid!

[LucifersTrip]

I'm slightly confused as to what you're doing....why do you have to convert anything to negative ground when AC127's are NPN, negative ground

link to the AMZ layout you're using

[Jaicen_solo]

I double, triple, quadruple checked my AC127 pinouts too.

And the penny drops...
I have a bunch of these, and they're all mega leaky. Try it with a 2N3906 first and see if it biases up right on its own.

[petemoore]

  IIUC, it's a virtual Gnd. FF which needs debugged, this is only based on vague data...usually the gain knob works but oscillation or other anomolies may be difficult to get rid of.
   The board for a FF is inexpensive and a battery or neg supply coversion is a small deal too. The FF will work if set up right, as will either of the two power solutions. This might simplify matters greatly because there are so many successful debugs using this approach.

[ninjadave7]

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

This was the schematic for the AMZ mod, the 2nd one down on the page, and why he did it.

[ninjadave7]

I've seen lots of boards for the FF, just wanted to do it on vero because that's what I have.

Thanks guys, for all your help so far.

[ninjadave7]

alright guys,
found some 2N3906's, put them in the renegadrian vero layout (http://www.aronnelson.com/gallery/main.php/v/Renegadrian/fuzz+face+7+buchi_+1_1.gif.html) and it's all as shown on the picture.  Checked my pinout and the transistors are oriented correctly.  Here are my voltages:
Q1 -
C - 1.549v
B - .924v
E - Ov (ground)

Q2 -
C - 2.20v
B - 1.548v
E - .818v

still same trouble, volume pot works, but not really any amplification, fuzz pot does nothing.  Measured the pots too and they work.  Double-checked wiring and it seems correct.

[Quackzed]

battery might be dead/dying... re-post voltages with a freshie.

[ninjadave7]

that was with a 1-spot, 9.4v.

[Govmnt_Lacky]

that was with a 1-spot, 9.4v.

Sounds like you have an incorrect resistor value somewhere in the power run 

[ninjadave7]

pulling them now to check...

[Govmnt_Lacky]

pulling them now to check...

PULLING THEM! 

Can't you just verify the color bands are correct first? I would do that before removing them to check. 

[ninjadave7]

By the colors they're fine, by pulling I meant pull one end so i could measure them without anything else in there.  But by the colors there's no issue.  That's my problem, everything measures correctly, is wired correctly that I can tell, and should work.  Maybe I'll post a picture of my build and someone will see what I've missed.

[LucifersTrip]

alright guys,
found some 2N3906's, put them in the renegadrian vero layout (http://www.aronnelson.com/gallery/main.php/v/Renegadrian/fuzz+face+7+buchi_+1_1.gif.html) and it's all as shown on the picture.  Checked my pinout and the transistors are oriented correctly.  Here are my voltages:
Q1 -
C - 1.549v
B - .924v
E - Ov (ground)

Q2 -
C - 2.20v
B - 1.548v
E - .818v

...and now you're putting a PNP transistor in a negative ground layout?  you flipped everything +/-?  after confirming you have all +/-'s correct, adjust the 8.2K to get Q2C voltage to -4.5v and then re-check to see if the fuzz pot does anything

...and you never explained why you had to convert anything to negative ground when you used the AC127's, which are NPN, negative ground

The AC127's should work in the layout you just linked to without alteration

suggestion: use & learn the schematic in conjunction with the layout:
http://fuzzcentral.ssguitar.com/fuzzface.php

[petemoore]

  Those FF resistors measure about the same in or out of the circuit.
   Measureing in-circuit, then if one seems way off from the color code..pull one end and re-measure.
  Otherwise a combined R can be calculated for a resistor in-circuit which has a bypass-R path, as an alternative to pulling the resistor. Pesky off-value resistors...can easily enough be pulled though.
   If the polarized capacitor[s may have seen reverse voltage, they can't be trusted and are probably damaged.