Why go with active preamp?


I've got 1) source, 15" I/C's, don't need a remote, and my CDP has a buffered output stage. So I've begun to wonder, why do I need an active preamp? Can the sound be tweaked enough with the power amp and source?

Any comments on why you chose an active over passive preamp?
Thanks
cdc
There's a lot of good stuff that's been said here, from seasoned experience. You can pretty much pool what has all been said, and try to get an idea of what may or may not happen in your experiences. I can pretty much look at each post and concure with some point, or all points, and say the scanario's mentioned here would likely be similar to what you might find if you experiement yourself. The key is that you'll HAVE TO TRY YOURSELF TO FIND OUT!
An easy way to compare what a passive preamp would sound like in your sytem would be to just get a good CD/DVD player that sounds very good through the analog out's, and that posseses a "gain control" or "volume control" and connect it dirrectly to your amp!(perhaps some sources have different gain and impedance, so beware) You can compare this passive set up to an active preamp you might be considering, then you can not the differences. You might also try tube preamps and better active SS offerings to compare that as well.
A buddy of mine has a Berning ZH270 with Merlin VSM-M speakers. We listened direct to the Berning through a Bel Canto DAC 1.1 and also through his CAT pre. We both much preferred the sound through the CAT pre. Much more enjoyable to listen to. We didn't feel the sound lacked the detail, etc. It retained the detail but became more musical. That's not to say through the Berning was bad. Hardly. It sounded wonderful. Through the CAT it was more musical and enjoyable.
i have never heard a passive preamp / direct out that had sufficent bass and mid-bass response. the mid bass respsonse is very slow and puddling.

also passive is very lacking in dynamics.

take a listen to a passvie unit / direct out to a nice tube /hybrid preamp and there is no comparson.

Try a bat vk30, audible L1, AR ls2bmkII etc... the soundstage will also snap into focus.

these are decent pre-s that are less than $1000.
With a passive preamp direct you should be looking for an amp with an input sensitivity under 1 volt. I use
a Gamut D200, and a passive preamp with the D200 set at it's .775 volt input sensitivity, with 5 meters of interconnect cable between the preamp & amp. Having just tried a active preamp for comparisons, there's no lack of dynamics, resolution, bass or treble response. As Marakanetz points out the midrange presence is affected.
In my system,the active preamp moves the midrange forward
as the volume is increased. Allowing that the power amp/speaker and impedance interfaces are good, adjustable input sensitivity on the amp and variable gain controls on the preamp would allow a user to dial in the sound they want, but there aren't many products that offer that feature.
i have 2 bel canto evo 200.2 amps bridged in my system
i am thinking of buying cary 306/200 cdp with volume
control and going directly to amps.the specs on amps
are input level for full stereo output is 2 volts,cary output is 3 volts.will i lose dynamics with this setup
thanks