Debug Fuzz Face Help!

[Ag_Nathus]

Hi all,

I am working on a arbiter fuzz clone using the pnp negative ground schematic at generalguitargadgets. (http://www.generalguitargadgets.com/index.php?%20option=content&task=view&id=154&Itemid=18354)

I made the circuit board using their template. Right now the bypass switch works so I can hear the guitar when the effect is off. When the effect is on, I can see the LED but the effect makes no noise. The only thing I did differently from the site was to use a lower resistor for the LED. (220 ohm) I have checked the battery, it is reading 9.3 V. I have also checked the pinouts on the transistors and the orientation of the caps and that seems fine. All the wires seem to be going to the right place and I can't find any visible bridges but I am not sure how to go through and check every connection. Does the multimeter ground lead go to the ground terminal of the battery, the ground lead on the board, does it even matter? Any advice on an obvious mistake or how to test further would be helpful!


Thanks!

James

One other thing... does the stomp switch have an orientation? As a three by three grid, I pretty much picked a random orientation and hoped that it was symmetrical and didn't matter.

[petemoore]

  Perhaps someone can help you with a PNP Neg Gnd FF
  This one works:
  http://www.generalguitargadgets.com/diagrams/fuzzface_sc_pp.gif
  or for another possible neg gnd FF, NPN Ge's on an NPN neg Gnd. FF...
  does the stomp switch have an orientation? As a three by three grid,
  Yes, looking from the side, and turning the switch, you can sight through the lugholes, oriented this way, then I use the right side middle lug for input, the left side middle lug for output.
  I just don't know about PNP _Gnd. ff's..
 

[Ag_Nathus]

Ok, thanks for the tip....that is the exact same design I used. So you are saying hold the switch so that if you look at it from the left or right side you will see throught the lugs and the top or bottom you will see the edge of the lugs? Mine is oriented the other way. Does this mean I have to undo all 9 connections? Since it works as a bypass switch now, do I have some of them right?

Thanks for the help!

James

[GibsonGM]

Some may or may not be right...I done this before, lol!  You should remove all connections, clean up the lugs, and start over.  Use a meter to check continuity and define which side is which once and for all.  I've had very similar results (it was even a pnp fuzz I did this with), getting the switch right is probably the major issue here.   

[Ag_Nathus]

Thanks for the help guys! I'll try that in the morning.

James

[R.G.]

You may be fine, as many people are, but doing a "negative ground" conversion of a PNP Fuzz Face is often an exercise in futility. Sometimes it simply can't be made to work, oscillating for inscrutable reasons. I advice people to do these things either NPN negative ground or PNP positive ground.

[petemoore]

Ok, thanks for the tip....that is the exact same design I used. So you are saying hold the switch so that if you look at it from the left or right side you will see throught the lugs and the top or bottom you will see the edge of the lugs? Mine is oriented the other way. Does this mean I have to undo all 9 connections? Since it works as a bypass switch now, do I have some of them right?
  There is a hole in each lug of the switch to aid in aligning the wire like a needle's threadhole. If you can see a lug through a lughole, or see through three lugholes, your eye is aligned with the switch so that the *right/middle lug can be input jack, left/middle can be output jack, the rest of the switch wiring will follow suit.
  ////If you're looking at the bottom of the switch, each time you turn it 1/4 turn it goes from 'correct' [like schematic] to needs to be turned 1/4 turn to be correct.
  Verify correct switch orientation for wiring by lughole sighting to find right/middle, then...right/middle should connect to right/top-not right/bottom, [hit switch one time] and it'll connect right/bottom-not right top.
  Make right middle the output jack, one lug up should connect/not connect when you test/switch/test. If no connection between right top and right middle is found, turn switch 1/4 turn-repeat test.
    See GEO for lotsa cool stuff and how the insides of switches work/look.
 
 

[Ag_Nathus]

Ok, I tried resoldering with the switch rotated 180 degrees and got the same thing, LED works, bypass works, no sound when engaged though. I then resoldered with it rotated 90 degrees and nothing worked, no sound, no LED... of course, when I unsoldered this time, one of the lugs fell off so I may have already fried my switch. I am going to try to pick up one at Fry's tommorrow. I think I will undo everything and try again. Anyone have any other suggestions before I start

The switch that I had had an 8 next to one of the corner lugs, but all the switch schematics I have seen show the 8 lug being in between 7 and 9, not on the corner; are there any other switch layouts? I want to try to get this one right as these switches are expensive :p