A few words, as requested...
The real old shit, I would image, would be a little more raspy and not as smoothed out as some of the later units. The more original units that I hand through my hands the better a understanding I had about how the pedals were produced so as time passed I was more able to set-up circuits in certain ways to achieve the set sonic goals.
Transistor section isn't about the device type as such. I'll use a certain transistor for a certain task as the gain will fall into a certain brackets. As in, I could use an AC125 or an OC75 in the first position and they'll yield the same result when combined with say an OC76 in the second stage.
Without over complicating things I tend to set-up the 1966 in two certain ways, the original units will display these characteristics also. Its very basically either smooth or raspy and then branches that extend from that. As in, a unit packing an OC71 will be smooth but alot smoother than a unit with a AC125 under the hood.
I believe Philips clip would have been my old unit, that had dual SFT's. That tone is at the extreme end of raspiness for this circuit type. I dig that sound a lot. Reminds me a lot of the fuzz tone on some of the early Grand Funk tunes.
http://stompboxes.co.uk/downloads/1966% ... %20mp3.mp3
The 1966's I send over to Japan on a whole are a lot smoother. Compare the tone of Philips clip above with Yasushis clip below. Same pedal type, different set-up.
http://stompboxes.co.uk/downloads/DAM_c ... uehara.mp3
All the new units have been pretty smoothed out, tone wise. I guess if you are after either one of the extremes you want either a dual SFT unit, mucho raspy torn speaker big hair tones, or anything packing a OC71, crispy fresh smooth as boobs tone.
Dunno if that helps any. It's always odd with this shit as sound is very subjective so better or worse is kinda in the ears of the beholder. I really like the extreme rasp killer bee kinda sounds some of the originals spew forth, but as an example of the subjectiveness I have been sent vintage pedals that sound like that and the owner may hate the shit out of it and want it re-biasing. Each to their own, ay.