Weiss's Medea+ flagship DAC's main changes are the new 32-bit ESS SABRE32 DAC chip, new output stage, integrated firewire input option, and glass fiber input option. Weiss says existing Medea DAC can be upgraded to plus status.
The new OP1-BP output stage is interesting. There is a general disapproval of operation amplifiers ("opamps"), but we just want to highlight that each integrated circuit ("IC") opamps out there are different, and then there are also discrete (non-IC) opamps. In the Medea+, eight bi-polar discrete opamps are used for current to voltage function in the DAC's output stage.
For those interested to tweak your own existing CD/DAC units, there is another discrete opamps that is available as after market direct replacements for IC opamps, the highly regarded Burson Audio's HD audio opamps.