i checked with a dealer of concert fidelity, who described the dac as a component which disappears. if this is so, it represents the modern tube sound.
the original zanden, sounds more like the classic tube sound.
so, unless one specifies a criterion for best, there are probably many fine dacs which sound different from each other, which would be recommended by their owners.
it seems that the question of best raises the fundamental question among audiophiles, namely, to color or try to be colorless, or the modern tube sound vs the sound of tube gear from the 60's.
the original zanden, sounds more like the classic tube sound.
so, unless one specifies a criterion for best, there are probably many fine dacs which sound different from each other, which would be recommended by their owners.
it seems that the question of best raises the fundamental question among audiophiles, namely, to color or try to be colorless, or the modern tube sound vs the sound of tube gear from the 60's.