The Fuzz Face series: 1-The Original (?)

A couple of years ago I got a blue Fuzz Face with the original Dallas-Arbiter England logo and I was under the impression that it was one of the 1970's silicon varieties.

For a long time, it's been a bit of a mixed bag sound-wise. I mean, the sound is really impressive, but I guess I just wasn't a good enough guitar player to get all the nuances of it. Also, it seemed to have a hard time cutting through the mix, either because of lack of boost or the muffled tone I got with my sloppy playing style. So it spent some time on my FX board, but in the end I had to come to terms with the fact that I just wasn't good enough to get it to work for me..

But, since I was building Bazz Fusses and had some good results with those, I decided to give the old Fuzz Face design another try, and I thought it would be easy to come up with a better sounding device than my supposed old original unit. (spoiler: that turned out to be harder than I thought)
I'll be looking at that attempt in the next blog post, but when I got a working unit and compared it to the sound of the original Fuzz Face I found that I was not even close to getting a box that sounded better to that one..

In the process of trying to build a nice Fuzz Face I read a lot about the unit and saw some pictures of the original Dallas Arbiter units (Technology of the Fuzz Face, Fuzz Central and the story of Dave Fox on Analog Man and the pictures of his Fuzz Face prototypes on the FoxRox website)

So when I consistently got results that weren't as good as the blue Fuzz Face, I opened up that one to look at that board once more to see if it would give up its secrets and I realized my unit wasn't an original one, but very probably a Dave Fox/Crest Audio early '80s reissue. From what I can tell, Dave Fox spent a lot of time tweaking the original schematic so I wasn't competing with a "run of the mill" Fuzz Face, but with a thought-out tuned box.. That certainly set the bar a bit higher..

Transistors are BC109C, input capacitor is a 1uF Philips, output cap is a 47nF film cap. The Q2 collector bias resistor is 6k2, setting Vce for Q2 at 4.3V, which looks good!

I'm not entirely sure where the 68nF film cap goes (it's no doubt there to tame some of the high frequency oscillations), it might also be between the +9V rails and Q1's base. What's surprising is that even though the BC109C's are high gain transistors, the unit sounds surprisingly open and without any low end choking. After having built a couple of Fuzz Faces myself, I know this is one of the more challenging parts of the Fuzz Face design.