Fuzz Face - HELP!!!

[HeaD]

Hi all, I have a problem with this Fuzz Face http://66.226.81.4/diagrams/fuzzface_sc_pn.gif . the Layout I have followed is this: http://66.226.81.4/diagrams/fuzzface_lo_pn_3pdt.gif , and I used 2 AC128 (hfe 50-60).
The Bypass is perfect, but unfortunately when I activate the pedal, it does not work.
I've tried to do a test with the audio-probe and have noticed that in a point of the circuit ( the marked point in green here http://img112.echo.cx/img112/6029/fuzzfacelopn3pdt9ii.gif ) there is a signal loss (signal loses volume). Can the problem be this?

What can it be? thanks for the help, and sorry for my english!  :wink:

[Karmasound]

Have you checked to make sure the caps are the right polarity.

Check that the transistors are in right.

Are you sure the transistors are good?


You are doing the negative ground version so there is going to be extra problems.

Do you have the positive and negative battery connections hooked up right?


Personally if i'm using pnp transistors I just use positive grounds. The batteries last a long time, or you can get an adaptor to power it.

Every FF i've built using negative ground versions have had problems. When I use + grouns they all fire right up.

[HeaD]

Have you checked to make sure the caps are the right polarity.

Yes :/

Check that the transistors are in right.

yes...

Are you sure the transistors are good?

yes, I've tested them...

You are doing the negative ground version so there is going to be extra problems.

Do you have the positive and negative battery connections hooked up right?

they would seem exact... :/

other ideas? :wink:

[Karmasound]

Maybe try using positive ground.

Flip the electrolytic caps around and put the red battery wire in the spot where the neg goes.

[HeaD]

thanks, but I don't understand why he doesn't work with negative ground.   :?

[Karmasound]

I don't know either. But a pnp transistor isn't really supposed to be run negative ground.


Try using + and at least you will know if it works. Then if you want neg ground you can always work from the point of knowing it works one way.

[petemoore]

thanks, but I don't understand why he doesn't work with negative ground.   :?

>>>Me neither, but I do understand [enough for the intended purposes] how PNP Pos Gnd works...

[HeaD]

ok... How can I modify this layout for the positive ground? http://www.generalguitargadgets.com/diagrams/fuzzface_lo_pn_3pdt.gif

[petemoore]

Start with a certain FF schematic, make the appropriate connections.
 Realy all you need to do is:
 orient the battery clip - and + to match your scheme
 orient the polarized caps so + is to the most + side of where it connects...
 and orient the reverse protection diode [if used].
 I recommend Pos Gnd scheme for PNP Ge's
 Alternatively I recommend Neg Gnd Supply for NPN Si.
 I've been using the Axis Face with 2n2369 Q1 alot lately.

[Karmasound]

All you have to do is wire it up this way.


http://66.226.81.4/diagrams/fuzzface_lo_pp.gif

[HeaD]

All you have to do is wire it up this way.


http://66.226.81.4/diagrams/fuzzface_lo_pp.gif

Yes I've tried so but I had some problems with led indicator because I use a 3Pdt switch... how to wire with 3pdt? Thanks again.. :?

[Karmasound]

don't worry about the led and switch.

just look at the board and make the changes on the board.


The positive power wire will go where the negative is now and the neg. where the positive is.

take out the jumper at the top and put it in the bottom, and flip around the cap at the base of q1 like in the diagram.

[HeaD]

don't worry about the led and switch.

just look at the board and make the changes on the board.


The positive power wire will go where the negative is now and the neg. where the positive is.

take out the jumper at the top and put it in the bottom, and flip around the cap at the base of q1 like in the diagram.

really? just change the Jumper and reverse C1?! it's simpler than what seems!  I try

[Karmasound]

and switch + 9v wire so it is in the ground spot.

just look at the boards and you will see the difference between them



http://66.226.81.4/diagrams/fuzzface_lo_pn_3pdt.gif


http://66.226.81.4/diagrams/fuzzface_lo_pp.gif


You might want to place a trimmer pot or a regular pot in place of the 8.2 R  so you can adjust the bias for 4.5v on the collector of Q2.


You will want .5v on the collector of Q1 for best sound.

[HeaD]

http://img18.echo.cx/img18/4369/fuzzfacelopn3pdt9uc.gif

is this ok?  :?

[Karmasound]

yes, but one more thing, look at the battery wires. Notice how they need to be switched?

[HeaD]

yes, but one more thing, look at the battery wires. Notice how they need to be switched?

I'm sorry... I've to reverse battery wires?

[petemoore]

I think you got most of the questions right so far.
 Starting A new thread would probably neaten things up a bit, there's a long list of things in this one to have to read through. Include only the info needed like what transistors and schematic.
 start with PNP transistors and use Pos Gnd suppply???< or...
 thats input or output caps + facing toward the circuit >< as this is the most positive side. If you not use polarized capacitors then, polarity is not an issue/either way.
 the 22uf cap on the gain knob, if Gnd is V+ then gets its + sign going to ground also.
 We just said V+ is Gnd so the red battery clip lead goes to Gnd. the black one to 33k 470R [or whatever that small resistor is youre using] junction.
 That's why it's easier if we're all looking at the one schematic...most of the connections are shown.
 I never blew a 3906 [wish I would have instead of the Ge's I damaged/blew].

[HeaD]

We just said V+ is Gnd so the red battery clip lead goes to Gnd. the black one to 33k 470R [or whatever that small resistor is youre using] junction.

And this is my problem... how to connect the 9V-jack? I've some problems with the led indicator in 3pdt.....

[petemoore]

9V jack? on a FF? I see reasons why not to...
 So still I THINK
 you have transistors for this
 and you have a schematic you've chosen?
 I not reading through 20 posts to sort this out again.