tube dacs vs solid state dacs

there have been a number of posts extolling the virtues of seceral brands of solid state dacs.

however, it would seem that the flexibility of tube variation, especially in the gain stage , should best the performance of most solid state dacs.

yes , it brings to mind the issue of tubes vs solid state, but i think the particular facility available to tube dac owners vs solid state dacs has not been sufficiently emphasized.