I have a reference line preeminence 1 series 2 that I am extremly happy with. It's a $1500 preamp that I got for $425. I will never ever go back to a powered preamp again. And what is cool is I will never have to upgrade it. No powersupply or circuits that could be improved in a newer model because it doesn't have any. No power to be corrupted. And the dynamics are amazing with so much air around instruments and a very dark and quiet background. But don't ever put line conditioning on your amp for the best dynamics. I think sometimes people confuse the cleaner sound, quieter background, and a pushed back soundstage for a loss of dynamics. I don't know maybe they just got a week frontend or a bad combo or something. All I know is I got way better dynamics since the signal is kept very pure. Hope this helps.
Passive Preamps
I have the EVS "Nude Attenuator" RCA version which costs $225. I didn't evaluate others such as the Placette Audio, Art Audio, etc. My preference is the type that eliminated one interconnect and mounts directly to the back of the amp's RCA. Has anyone done cross comparisons between passive preamps? I have seen passive preamps as high as $1000. My system - Sony SACD player, Harmonic ProSilway II interconnects and a Bel Canto EVo 200.2 Digital amp.