Kevin,
Without the schematic, it'd be pretty tough to tell you the electrical order of the the tone-shaping circuits without dissecting them. What I can tell you is the tonal possibilities available boggle the mind.
The pan circuit alone is a very effective tone control. Guys like BKBASS Barry use individual P/U vols. and a master vol. for pickup selection...they are very effective tone controls in there own right (Series II elecs. also help, LOL!). In addition, every other control seems to affect every other control. In other words, you really need to be a tweek freak in order to really dig this control layout. While I really apreciate the enormous flexibility with regards to tonal possibilities, I tend to be more of a set it and forget it kind of guy. This set-up makes repeatability of settings VERY difficult. There are no knob/pot detents other than center (vol. excluded) and extreme limits of travel. Luckily, it's hard to get a BAD sound out of this thing. Having bass/treble cut AND boost (even though it functions as a master tone controls) gives you unbelievable piano-like high-end tingle as well as thunder at the same time! As far as preamp overdrive, the active circuitry makes it very easy to overdrive, especially with my Eden WT-550. I, similar to Gary, set my amp basically flat, tweek the amp sweet control and the eq to suit the room, and then shape the tone via the Alembic active stuff. Once you get the room to sound right via the amp, you can dial-in just about anything you can dream up via the controls on the bass itself. I've never seen a passive instrument (or another active system) shape tone with the frequency range that my Alembic does (excepting other Alembics, of course). I can just imagine a Series jobbie...I have all I can do to work one filter, LOL!
One word of advice: Be careful what you wish for! LOL! I wanted an extremely versatile Swiss Army Knife of all basses, and I got it. I tried to duplicate that J-bass vibe and tone(s), but in a lighter, high-end version with premo materials and a verstaile electronics package. I got much more than I bargained for!