The bassier of the 2 positions sounded to me like what I would expect to hear from an unaltered pickup located so far from the bridge. The other position certainly sounded like a bass cut, if not a mid boost as well. It was a tone unlike any sound I've heard on any other bass.
That's how mine sounded as well, except that the bassier position was distorted, until I took out the coil. I can't say what went on in any other basses beside my own, but one thing I know for sure is that in my bass it was a bass cut and not a treble cut. And yes, Guild said it was a bass boost but as we all know for it to be a true bass boost it would have to be active.
That said: In general, if I take the output from a PU and run it through a resistor, does that cut any frequencies? If I take the output from a PU and run it through a capacitor, does that cut any frequencies? I would say the answers are No and Treble. If someone else has different answers then we have found a fundamental source of my confusion.
That's what I've always thought, as well. But at least on my bass, it's not a resistor or a capacitor that it was running through; it was a coil, and my understanding has always been that coils cut low end.
Not sure I want to believe the blond but the black, pre-Dark Star is definitive. One of the tricks I use to tell whether a SF I was converted to a SF II is the thumb and finger rests. I have never seen a SF II that left the factory with rests, but I have seen several conversions where the rests were reused.
Fair enough, but the Black one had finger rests as well. It's kind of hard to see in the photo, but they were there - I saw it in person. To me it seems like too much of a coincidence that two basses, both with 1970 serial numbers, the year that they transitioned to the humbucker, would have the exact same configuration (pickups, selector switch in a different place, no master volume) and not come out of the factory that way.
But maybe they didn't?!