Altering the tone?
 

Here's a good question for debate. Does adding a switch alter the tone of the pickup? I don't mean does the switch give you more tonal options (of course it does). I mean, if the PUP was wired in parallel before the switch, does the addition of the switch alter the parallel tone?

If so, is this change purely subjective, or would there be an objective way to prove it?

The additional resistance provided by the conductors in the switch is so small, any perceived difference would be purely in the mind of person who's listening. Objectively, there would be difference, yes, but as far as the human ear's resolution of such details goes, there's be no perceptual difference at all.

+1 :cool: