I can run my B+K preamp in passive mode, and I've spent the last couple days messing around with passive vs. active mode. One might think that because it's a decent, but not terrific preamp that passive would sound better. But I've found exactly what jsadurni found--better imaging, brighter and the like with active mode. The voices seem to hang there in the air with the active mode, instruments come from outside the speakers. It does reveal imperfections--some disks are too bright on active mode. I really expected to prefer the preamp in passive mode, but I don't.
Cheers,
Matt
Cheers,
Matt