The Bryston, at its best, is very similar sounding to the Concero. The catch is that it takes very careful transport matching to get to that level - when using a mediocre source, it sounds merely good but not great. My Cambridge 840C is a prime example - using it as a transport, the BDA-1 doesn't really sound much better than the Cambridge's internal DAC. Different, yes, but not decisively better. Using my JF Digital HDM-03S music server brings things up several notches and shows the Bryston as having some real potential. The absolute best I've heard from it? Being fed by the Concero as DDC using the apodizing filter. "
That bit from the review hit me like a brick, a sort of "Ah Ha!, something really important being said here about selecting a DAC!", namely it seems to imply that given a "mediocre source" the result (sound quality) will be to a great degree depend upon the DAC selected. One particular DAC might perform up to, or close to, its best even with the "mediocre source", another DAC might not even hint at its potential.
That seems like a huge differentiating factor for DACs in general. Say I'm considering getting a DAC and planing to use my existing CD Player as transport. I have no idea if the CD Player as transport makes for a mediocre source or an excellent source. Or maybe I was planning on selling a pricey CD Player (to help purchase the DAC) and replacing it with a cheap second hand CD (or DVD, or DB) player as transport.
Problem is, in general, how would you know? ... how to qualify a DAC as a design that doesn't (v. does) require a high quality transport.