Hey all.  My first post here but glad to have stumbled on this place.

So I just built one of these (my first foray into effects building) And its quite cool I must say.  I'm sure many of you are familiar with this project - its basically a fuzz face circuit that uses one silicon and one germanium transistor. There is an added blend knob that I guess you can blend between the two -  I think - Mine doesn't seem to work.   I get a great variety of tones out of it by adjusting the volume and fuzz knobs but I'm wondering if there is even more mojo I'm missing with this apparent blend knob. I also think its weird that except for this blend pot, the pedal seems to work great.   Has anyone built one of these puppies?  is that third knob just really subtle or am i missing something.  I checked and double checked my layout,  I have strong continuity across all solder points.  There is that .01uf ceramic disc cap just before where the wire comes off the pcb and I'm wondering if I may have mistakenly put it in backwards,  (do these disc caps have positive/negative leads like their cylindrical cousins?) 

I'm pretty green when it comes to electronics, where does one start to trouble shoot something like this?

Cheers, I apologize in advance if I'm posting this in the wrong place or transcending some forum etiquette

the blend knob is a tone control that gives you a fatter sound in one direction and a thinner sound in the other.swithes emphasis on the .01 and the 3.3uf caps...it is kind of subtle.with single coils you may want a fatter sound..with humbuckers it is the opposite.you dont have to worry about polarity with ceramic or poly caps..just the electrolytics(aluminum/tantalum)if you socketed the transistors then you can try different ones to see what you like best

hmm, interesting.  I guess i assumed it would be a lot more obvious.  I do play either a tele or a casino, so single coils.
Thanks for the reply.

cheers

very glad to hear you built it!

this input cap blend can be pretty subtle. for more drastic effect, try a .005 where you have the .01, you should be able to hear that pretty well.

also, the rest of the circuit needs to be biased well with a good gainy ( 110 or better is my recommendation ) ge trans for Q2 to bring out what this control has to offer.

I've been building an all-silicon easy-face variant with BC108C transistors and find the blend control really effective with a fair bit of variation.  It goes from a pretty standard fuzz tone to a nice juicy bass boost.  I dropped the .01 to a .0047 for bit more thinness at the one end (kept the 3.3 at the other end).  I tried going even lower but beyond .0047 things got too thin sounding.