I'd help on that if I could, but (1) I haven't had any gear with Burr-Brown DAC's and (2) I haven't gotten to hear the 990 yet. Since there's going to be more to how the unit sounds than the DAC that is used (we need to draw out control volume a bit farther out to encompass the entire signal path inside the unit), the best test - some might say the only test - is to wait until we have a number of them in people's hands and have a chance to listen to them.

For CD playback, the 990 does appear to have an analog bypass option similar to that offered on the 950 - which allows you to readily choose which DAC you listen to for CD's. Not only does that give you the flexibility to use the best DAC in your equipment rack, but it also lets you compare the two pretty readily.