Yes, this could go in any one of several forums, but the amp/preamp choice is probably the heart of the matter, so here it is.
I find I do almost all of my listening -- headphone and speaker -- at my desk now, so I'd like to upgrade my current (and, I admit, quite adequate) setup to something with a little more polish. I'm very happy with the Duet and the Senns, so those probably stay. Source is Apple Lossless from the iMac -- secondary goals are simplicity, reasonable component footprint and (again, I admit) good looks.
So far I've looked at:
-- SE tube head/power amp (Cary SLI-80) to passive monitors (Dynaudio Audience, Totem Rainmaker or similar)
-- SE tube head/pre amp (Zana, ??) to active monitors (Dynaudio BM6, Quad 12L etc.)
-- New balanced firewire DAC (Mini-DAC) to balanced SS head/pre amp (GS-X, B22, ??) to active monitors.
Would be buying used as much as possible for budgetary reasons, which obviously limits choice somewhat. Any thoughts appreciated.