Hey guys, I also have the CD6000KI and I installed a pair of silver Audio Consulting transformers in it last year that I bought from Audiocom International.
I currently have the primaries connected directly to the output pins of the post-DAC opamps and the secondaries go straight to the RCA sockets.
The opamps I have installed are two pairs of AD797BRZ's.
A year later, I've been doing more reading about what exactly the opamps are for and I'm struggling to answer the simple question "can I do without them altogether?".
A year ago I was incorrectly under the impression that the opamps were performing I-V conversion...but my player has a V-out DAC I now understand! I've been studying the player's schematic and there seems to be some kind of filtering arrangement prior to the opamps (as mentioned by someone above). Are the opamps just buffering the output? Is this required with the transformers I have?
Because there are two DACs, there are 4 sets of outputs per channel that seem to be combined in to 2 per channel by the opamps? Reading the datasheet for the DAC, it seems that the pairs of PWM outputs are 'quasi-symetrical'...so are the opamps performing a kind of 'superposition' of the signals? Is this an integrator?
So many questions...sorry!