Sorry Mac my bad. What I should have said is that not all active splits have full gain control on the pre-amps, so they aren't as adjustable as a mic-pre on a desk, other than the XTA model most of the others offer switching between line/mic level eg the Klark Teknik DN1248 ( the one that seems to crop up most often in the UK, in my experience anyway), so the mic-pre is just to accept and distribute a mic level signal not to change its gain level, so in effect you set the incoming level to the splitter and thats that you aren't relying solely on it for your gain as you can still adjust independently at each end of the multi.
That'll teach me to post when I get in from a long long gig with a horrid load in and out, and a 6 am curfew for a student ball.
Regards
Charlie