55-01 with OBP3 Pre question

Electrically it doesn't matter what pot the frequency switch is connected to, as the switch works independently from the pot itself, but its not very intuitive from the players perspective to have the mid frequency switch on the bass pot. As far as the active/passive switch doing nothing, it sounds like it just isn't connected, at least not correctly. Someone did a bad job installing your preamp.

 

Usually they're on the same pot so the wiring is local istead of running off to another pot.
Someone may have been tinkering with the wiring.
Best to get the Aguilar wiring diagram and go over things well.

 

The OBP-3 isn't stock so your best bet would be to download a wiring diagram and rewire (or move pots) as necessary.