I have had 4 passive preamps and many active ones, the passive line goes from First Sound to Axiom, I am currently using a Monolithic Passive in the meantime I receive my new preamp (active again).
Passive preamps (as noted above from others) are very transparent, fast and revealing units, only top-end preamps (Metaxas, ML or Gryphon) come close in those regards, unfortunatly for me my new systems need of the work of an active preamp to bring more roundness, dynamics and soundstaging (yes - sonic artifcats at the end).
Good luck
Fernando
Passive preamps (as noted above from others) are very transparent, fast and revealing units, only top-end preamps (Metaxas, ML or Gryphon) come close in those regards, unfortunatly for me my new systems need of the work of an active preamp to bring more roundness, dynamics and soundstaging (yes - sonic artifcats at the end).
Good luck
Fernando