I built this last night on stipboard (a nice quick easy build!) and amazingly A/B'd it sounds almost the same as my NPN Ge Axis Fuzz. The Ge version has a bit more 'fizz' but to the listener the two are very obviously very similar. The only problem I have noticed is an oscillation which comes in when the controls are all on full. I know this has happened to other people who have built fuzz face type circuits.
In my case it may be due to the BC109C high gain transistors I put in or the fact that I have not put it in a box yet but just connected it to my test rig so it isn't shielded. I will try some different transistors tonight as they are socketed so that won't be much of a problem.
I would like to thank you for posting this new design and for all the effort you have put in to make it avilable.
I had the same oscillation problem on the Ge' Axisface I built. This was bacause I used negative ground wiring - I prefer to use a mains power supply. I cured the problem by putting a 10k resistor in series with the input. Of course this also served to clean up the fuzz a bit, but not drastically, and I don't like to use maximum fuzz anyway.
The Axis Face Silicon Rev. 3 has a regular 50KB (linear) pot on the input...the "Smooth" control. It serves several different purposes in the circuit. First, it will reduce the "fizziness" of the fuzz and smooth it out (hence the name). Second, it will help to prevent RF interference in the circuit. It will also help a wah pedal work better if you put the Axis Face in the signal chain after the wah pedal. I still recommend that the output of the wah pedal be buffered, but sometimes even that doesn't seem to have a whole lot of effects for some reason
