How can an active preamp possibly help?

Are you saying you're going straight line level to your amp? Does your cd player have a digital volume control for varying the gain output? Or does your amp have volume control capability?
Either way, I'VE NEVER heard ANY DIGITAL VOLULME CONTROL, or passive set up, which has proper dynamic capabilities! The sound is always less dynamic, and seems flatter over all! If you're listening to Rock, heavy dynamics, Home Theater, or other, the sound is always not as strong!
Anyone who thinks this isn't correct, needs to just hook the 6 channel out of their DVD player dirrectly into their 6 channel amp(or whatever) and process the sound in their DVD player, with no preamp/processor involved!!! You'll get WIMPY, LACKLUSTER, DYNAMICLESS soundquality everytime!..NEVER SOUNDS AS GOOD!
I've come across a ton of audiophiles that are two channel buffs, who insist on just going ANALOG out of their dvd, and into their fav 2 channel preamp! Or guy's who go out of their CD player with volume control, dirrect into their amps! This has it's drawbacks in the form of weak dyanamics and bass comparatively. You couple that with the fact that the vast majority of guy's like this use speakers that are very polite, laid back, and dynamically challenged passive auiphile speakers, and you get anything but dynamic transparancy!...EGAD!
So, if you do have some sort of volume control from either your cd player or your amp, you're still not getting the dynamic capabilities you're intitled to, I find.
Good luck

I like to simplify the ACTIVE VS PASSIVE (or dirrect source to amp) scenario like this:
...with out being technical, it's usually like the difference between a HONDA Civic that can over rev it's engine and RPMs while going 120mph, vs a Turbo Porche that has much more snap,torque, overall power, response, and performance at the same 120mph!!!
In the case of most passive set ups(or no-preamp set ups), sure you can get the overall volume level up. But what seems to happen is a lack of overall dynamic control and body to the sound, which an Active preamp set up can overcome by proper amplification of it's signal! Even weaker amplifiers with higher wattage ratings can push the volume level higher, but it's also flat and 2 dimmenstional, and strained as well! (i.e, cheap reveiver amps). I'm also not so sure that just having PROPER IMPEDANCE MATCHING is the key. I think you can still get a good impedence matcy between CD player and amp, and still not get the dynamics you would from a properly designed active preamp! Hum....
Also, for the record, I've talked to PLENTY of aduio engineers and speaker/equipment designers over the years, and they often think things are a matter of simple mathematical and physics equasions! What I find is that usally these are the guys that don't have the best sound from their systems also! There's an old saying.."if it ain't broke, don't fix it!" And the quality active preamp works for all practical purposes!
Anyway, I've yet to hear even the expensive Wadia's sound as good dirrect to an amp, as they do with a good preamp infront of it! That's what I find anyway. And I've heard a lot of passive set ups!...a lot!
THE ONLY way you'll find out the differnce, is to try both, experiment, and then you'll know!
good luck