Kensetsu - I'm by no means an expert, but I would say that it definitely depends on your CD player. I have gone back & forth between passive and active more times than i would care to admit, and finally determined that there are no hard fast rules when it comes to this whole question.
Ironically, when I had CDP's with variable output/volume (Opera Droplet, Audio Aero Capitole II) they BOTH sounded better going through my then BAT VK3ixSE, as opposed to going "straight" direct to amps. (Seems like it should have been the other way around as these are both designed to run "direct").
Now, with my Esoteric UX-3SE, it was actually a tie between the BAT and my Reference Line Preeminence 2b, with some splitting of hairs in these two areas - the bass is slightly tighter and more authoritative with the active, but overall transparency and soundstage is better with the passive.
I am not parked in one camp or the other (passive vs. active) but I've always felt that the absolute BEST that an active preamp can do is leave the signal unscathed, and that this just seems impossible given the amount of circuitry the signal has to pass through from beginning to end. Unless you can afford the absolute BEST active preamp, in most cases a passive seems a slightly better alternative, IMO (and again, if your system is strictly CD based).
So again, what have I taken from all this so far?? It all depends on SO many variables - output impedence of source device, output voltage, interplay between source and amp, interconnect type and length, speaker sensitivity, etc., etc. (Also, BTW, I have found much better results using XLR balanced throughout).
I guess experimentation is always the key - good luck!