Agree with Rewiiki ("there is more to a good DAC than a good DAC chip")--most manufacturers pay about $5 for a Burr-Brown chip after their quantity discounts (that is, most digital audio manufacturers realize superb economies of scale with chip manufacturers, maybe the reason for the CD revolution int he first place). I have found the most important parts of a DAC to reside in the analog output stages and the power supplies. I prefer DACs with tube output stages (esp. Manley, Audio Note) and stay away from the op amp output solution. The numbers game (16bit/20bit/24bit) has not been as crucial and I--like Redwiki--find 20 bits adequate. Have experimented with D-to-D Bit conversion and it has resulted in lowering the noise-floor, through dither and noise-shaping, but not enough to the point that it makes digital much less fatiguing to listen to.
