Perhaps Geoffcin would back me up on this. Anyway, I'm getting on very well with my Adcom GFP-750 used in passive mode in combination with a pair of Monarchy SM-70 Pro's.

The viability of a passive preamp / power amp comb depends on the preamp output power amp input impedances -- or so I' given to believe. Short interconnects are desireable, though in my case I'm using 6 foot, balanced interconnects with no problems I can hear. (The Monarchys used as monoblocks prefer balanced inputs for optimal operation; there again I can't say I understand the techincal explaination).

How other than the impedance thing, my question is: how could a tube preamp be better than "no" preamp? My pet theory is that tubes added enough pleasant, low-order harmonic distortion to mask the unpleasant, high-order harmonic distortion that S/S cause, especially those that use a lot of feedback. This means that the tubes are actually adding distortion to produce their euphonic effect.