I have a Carvin DC127fa with the active electrics only. I believe the DC 400W has a push pull pot for active/passive on the volume knob.
Also look at maybe getting a DC127 and optioning it up to a 400, that is what I did. For example a dc127 with a walnut top and 5 peice neck at 50% off the option would be cheaper.
Mine is the base 127 model with a flamed top, abalone blocks, fishman bridge, coil splitters, swamp ash body and such. Mine is an early 2003 model. It plays very easily.
Things I wish I had gotten. An engraved truss rod cover, I could still do it myself if I was careful. A Hotter bridge Pickup, I have the old C22t, the dont come with that anymore they have the hotter C22B, I got to get one of those. It is a great guitar, but I dont know so much, it is my only electric at the moment nuthing to compare it to.
Here is a wonderful resource. .http://forums.carvinmuseum.com/
The people are most friendly for being a non Deadhead community
;), ask any question. They have more info than I could provide. And you will get honest advice uncensored advide. A great many of the members are giging players. FWIW, there is a good mix of guitarists there from more metal or shreder types to blues and classic rock types. For example, the guitarist from Barefoot Sunrise is a member and plays a DC145 a hum single Hum setup. they are from Delhi, NY and play a bunch of GD.
Lemme know if I can answer any question.