Yes - instead of the output going to the jack socket it goes via the preamp so whatever is selected on the 5 way (neck/neck + bridge/bridge/bridge+piezo disc/piezo disc) goes through the preamp unless bypass is selected.
Thank you Keith for the kind words - decent cigar boxes are hard to find in the UK so it is a 35mm photoslide box - if you want to hear how it sounds there is a video showing the difference between the passive and active output http://www.cigarboxnation.com/video/comparing-cbg-pickups (ignore my bad playing:o))
Comments
So are you running passive electric PU's thru an acoustic pre-amp?