Slanski62, try the passive! The complaints about lack of drive, thinness or lack of involvement using a passive are completely system dependent. I am currently using a passive (Audio Synthesis) to Manley tube monos via 5m (!) of Nordost, driving 93db efficiency speakers and the results are fantastic. There will be exceptions to every "rule" proposed in the posts above which will depend on the particular components in your system, the particular passive you use, and your own sonic tastes. For instance, in my system, the passive brought significant improvements in the areas of transparency and tonal refinement with no loss of dynamic verve; there was a reduction in tonal fullness compared to my active pre, but the change was a welcomed change since my system was overly full sounding to begin with. You will never know the real answer to your question until you try it.
Re Nelson Pass and the integrity issue: Isn't it obvious that even if a manufacturer believed that a good passive is potentially superior to any active (I believe it can be) in a specific system, that given the fact that an excellent active will work well in many more systems than a passive will with its much more specific requirements, that this is the reason that a manufacturer such as Pass chooses to offer active preamps?
Slanski62, did I say "try it" :-)
Re Nelson Pass and the integrity issue: Isn't it obvious that even if a manufacturer believed that a good passive is potentially superior to any active (I believe it can be) in a specific system, that given the fact that an excellent active will work well in many more systems than a passive will with its much more specific requirements, that this is the reason that a manufacturer such as Pass chooses to offer active preamps?
Slanski62, did I say "try it" :-)