Credibility. I suppose I could attempt to nail down DAC's only in even my many system evolution's.
Being fairly rooted in Analog, I started small in digital. Turntables, with a good needle, good phono preamp, have a magical way of making most all systems engaging. Never heard a CD player do this, or a DAC for that matter.
I will just say, I played around in allot of under $5K territory in DAC's. Tried a couple DAC's in the $10-15K range. Then I got my first taste of Totaldac. Got in with the D1 Dual. First DAC I heard with no color to the sound. It sounded like neutral music, and everything around it mattered more. Microscope to the rest of the system if you will. NOS DAC then meant to me, "no color". Discrete DAC then meant to me "no annoying artifacts". I can now hear, the rest of my system.
This was the bait that got me hooked. I knew then, given my systems capabilities at the time, I had to have the best one of these to build around.
Hope this helps.