Those things are called pickups, and it is well known that pickups have nothing to do with tone, it's all in the wood. My guess is that when the switch is forward, you are getting more maple ( from the neck ) and when it is back, you get less maple. That's the only scientific explanation I can come up with.
The effect is most pronounced when the guitar is plugged in, but my sensitive ears can hear the effect of the switch even when it is not ( plugged in. ) Everyone knows that the true tone of a guitar only comes out when it is not plugged in. Amplification of the electronic metal parts debases the pure tone of the wood.
This wood has also been strangled with grain filler and polyurethane. All the resonance of the pores has been clogged up for the sake of a smooth shiny finish. Sometimes, I like to imagine being very tiny and sitting inside the enormous unfilled, unclogged, practically unfinished pores of a Les Paul Studio, totally surrounded by tone. Gibson is uncompromising in their pursuit of tone, and refuses to ruin the wood by applying an attractive finish. Gibson is a company that is steeped in luthier tradition - pickled in it, if you will. They charge a premium for toneful extras like a sh!tty finish, but it is worth it to the true artist. Rickenbacker is also pickled in tradition.
