So all pedals were tested at 12v using a Yamaha Lord Player(les paul) and a Philip Kubicki Telecaster. The pedals were run through a variety of settings on both guitars starting with nature and drive knobs full ccw, incrementally increasing volume, then nature, then gain at a wide variety of settings.
We began with the bf #483. This pedal had the most gain and brightest(still warm)eq of them all. Considering the trim pot on the deluxe was only tested in the full ccw position, the bearfoot was the rockiest standing on its own. From there the Deluxe next had more clean head room, thicker bass eq and smoother od. The BPB was never engaged but the wonderful buffer probably contributed to the overall smooth increased clarity. Next came bjfe #173. Really the middle of the road all the way. Warm bass thump, moderate but gain starting clean to pleasingly aggressive and nice headroom. Classic hbod v1 tones here. That brings me to my, from memory, recollection of the first hb I owned #133. I remember this one having slightly less gain than the previous 3 and a touch more bass. My favorite sound/feel out of those tested to this point by subtle shades. Ultimately we tested #93. This is the warmest, darkest and least gainy/grainy bee I have played. Probably a touch more cleanish headroom. The biggest difference is the overall eq range of the nature knob. It starts with a lower overall bass mids ccw and progresses to the lower part of the upper mids cw. Although it is not as wide, I prefer the ability to adjust this sweet part of the eq range. This early one has a special mid low punch not found in the latter ones. I suppose I will consider this one (as well as the rest of 6-99) part of v.75 and the first 5 v.5. I am especially interested in checking out one of the first 5.
Not sure still if there were specific #s where circuit changes were made, but my experience of generalization is as the #s increase so does the gain , ,brightness and upper range of the nature knob. I hope this helps anyone interested in these pedals. You cannot go wrong with any of them. They all sound great! It is only a matter of how you want to use them and what your tonal preferences are.