In a perfect world I'd like a completely passive option.....eliminating the electronic tone shaping from the circuit but that isn't available with this unit but there is a passive tone control on the 4/5 knob configurations. Am I correct in assuming that this is simply an active tone version of the normal tone on a passive system? If it's different, how so?

Normally I'd just go for the 4/5 knob version just to have all of the bells and whistles but the bass it's going in is a Ric 4004 Laredo that currently has volume, tone and a pickup selector toggle so the 3 knob configuration would be a more direct and aesthetically pleasing swap but I'm willing to break out the drill if it's worth it.

http://www.bestbassgear.com/acg-eq-02-two-pu.htm

If you find the tone knob on your bass is important for you to have than you may want to consider getting one with the ACG preamp. Without it you'll still get more tones than you know what to do with out of the preamp. For what it's worth though, the tone knob on the ACG pre is the best tone knob that I've come across, hands down.

Thank you, that's helpful!