What is the best DAC under $500?

I am looking for a DAC that I can use with my CD player and also computer. I have been looking at the following 3 DAC's:

- Grant Fidelity Tube DAC-11
- Shiit Bifrost DAC
- Emotive DAC

I would appreciate Audiogon members thoughts on these and other DAC's they would recommend as the best DAC in this price range.