ImhoIndeed. That is certainly the way I am leaning, whether or not tubes are involved. Though I recently have started getting back into tube gear after a long absence.
I'm not sure of how much of a gap can be bridged by using a high-quality preamp between DAC and power amp but I can say that my recent comparison of using a D'Agostino Momentum HD preamp vs what I'm listening to temporarily -- my dCS Vivaldi APEX directly into my power amp -- has reinforced my early experiments when the Vivaldi was new, although the Vivaldi direct sounds very transparent and has wonderful clarity and low-level natural detail, when I had the D'Agostino preamp in the system the sound was all of that plus much more weighty and vivid and more 3D as well. So the virtues of a preamp, at least in my system, are pretty clear.
Steve Z
The pre is the soul of the system..
Mn