Like what James has said above. But spec wise the PCM5121 is very similar to PCM5101 (the stepdown version of PCM5121, also hardware control only). I'll venture a guess that they both share a large part of the internal circuit except for the hardware vs. software control portion, so there is a good chance they will share similar sound as well. That is also the part on TI tends to have a similar flavour of their own in all their PCM series of DAC chip.
Nice to hear this move, I am appreciated that. :D
But power gain opamp still have not decided yet..