Super late here...first, thanks Bjorn for all the great info and back
stories...great stuff.
Ok we all love Fuzz, and different Fuzz flavors...TB MK I, MK II, 70's 3-knob
TB with the trio of STC transistors(top hat ones), Buzzaround, Big Muff(s), etc
But like the other ubiquitous, in the top 5 vintage effects list, the TS-808, I never
got on the right with a FF, though I tried...had one or two nice silicon examples that
were tighter and brighter and more stable than a few of the germanium versions I had
including a "custom" made one from a then recommended EE designer, I overall
preferred the warmth and vibe of the germ version, though as mentioned previously,
not without want of a tone control for more clarity/bite, especially with humbuckers(which I predominantly play) at higher Fuzz settings...having said that, because of the crudeness and quirkiness inherent in the circuit, it seemed a more "realized" and focused ideal Fuzz sound with single coils because of the difference in load seen at the front end, and that reduced string area/harmonics being sensed...but then it sounds, Bjorn, that you have already accounted for this with the SF;)
I might offer if not a tone control, maybe the addition of a bright switch for any required treble lift above the cable used/humbucker application? Or possibly a properly voiced mids knob for a little extra focus if needed? I do realize that you don't get something for nothing circuit-wise, and maybe then more so with the FF.
Lastly, I might add in that custom germanium version I had, it had a bias trim pot...might there be any tonal benefit to a top mounted bias pot, in a range of course that keeps the circuit functional?
Just some musings from mental notes I made several years back when I had the
last one...I REALLY wanted to bond with it more, because, also as previously mentioned...
Fuzzes ARE our friends
and it's a connection kind of like a sonic military credo, "Leave no fuzz behind"