From my limited experience with Pass product (ran a X-250 with X-2 pre and many other pre's) for about 5-weeks, Pass pre and power (or run seperately)are highly resolving, focused, fast, detailed and "clean" sounding whereas Classe 201/301/401 I found to be more organic in its palpability, soundstage dimensionality and sheer musicality.
peter jasz
peter jasz