did not find anything on the mcr510. I can only guess that it may be a cirrus logic.
which is the best of them all ? I have read that the DAC chip is only part of it, there is an analog section, power and how they are implemented to consider and that specifications are not the only way to evaluate a DAC (important but not only)
1) from the article sidvee posted "Enjoy what you want however you want to enjoy it, and dont worry about how others do it. Just dont say your system is better than mine"
2) having said (1) IMHO the PM6005 (which I have, same DAC) sounded very good to me. Till I found something that *I* liked better. But the CDP6005 is the best, the internet says so. No idea don't know