Fuzz Face volume!!

[elfito]

i had spare caps and resistors so i went ahead and got a pair of silicon transistors (2N2222A can), i followed the instructions on this page http://www.diystompboxes.com/analogalchemy/emh/emh.html  and also use that schematic and it worked fine ,the only issue is that if a roll back the volume on the guitar by the smallest notch it muted the signal
what can i do here?


also how can i stop the pedal from being an AM radio receiver?

[GibsonGM]

The FF might need to be in a metal enclosure to stop picking up RF noise (radio frequency interference).   Try adding a 1k resistor to the input, that might help, and will also raise the input impedance a tad (but will also attenuate the input signal a little). 

You're probably losing signal when you turn down because the input to the FF is "LOW IMPEDANCE".  And so are your guitar's pickups.   When you turn the vol down, you're actually making a voltage divider.  That, and input capacitance, are 'robbing away' the signal, and the high frequencies go first.  It's a troublesome problem with fuzz's, some are better than others about this.   

What values did you use for your resistors?  That can make a difference....

[23]

Ive built si FF and in the sake of trying to make the wiring as pretty as possible got RF problems, when I shortened up my grounds it stopped the radio stations, plus putting it in a metal enclosure....

[Speeddemon]

Could it also had to do with proper biasing (around 4,5-5V) of Q2?
I remember that mis-biasing can lead to gated, stuttery sound (a 'feature' in certain fuzz pedals these days...  )

[GibsonGM]

Originally, misbiasing was just a characteristic of the early germanium transistors.  They would drift with temperature and go out, giving you the splatty sound.  That's why the Dunlop FF case is so damn heavy!! Keeps the temp stable.  Plus, there are other components that can be added to help out the bias, like thermistors etc etc.      That's not gonna have much to do with radio pickup UNLESS you go into class B, maybe!!  But it will affect the 'quality' of sound you get.

The RF pretty much has to do with lead dress around a high gain transistor (that is why the FF calls for medium, rather than the 'highest' gain you can get), and shielding.  And input capacitance working with your volume pot to create a filter, rolling off very high freq's where the RF lives.    Try some series resistance, see what that does, but first I would get it into an enclosure - you can't tell much with it out in the open, it might go away completely once it's in the metal box!!   

[elfito]

you guys where right, Q2 was not getting bias, so i lowered the R3 to 200 ohms and used to trimpot for R2 and i was able to fix it.
the RF got away too,i can only hear it with the volume up but its to mild and i know that i can get rid of it by putting the effect in a enclosure

thanks for the help guy!!