Using HDMI output on Sony 5400ES and OPPO BDP-95

I own both of these coveted players and recently acquired a NAD M51 DAC to be used more for music played thru my laptop. I noticed both players are equipped with HDMI outputs (and the NAD has HDMI inputs) and figured let's see what happens if we try to play SACD's thru the DAC. Both worked. However the OPPO was only able to play at 88.2khz no matter how I configured it from the onscreen menu. I'm pleased to say that the Sony was able to output SACD at 176.4khz (which I think is pretty close to full DSD). I'm also pleased to say the Sony needs no onscreen menu. Although the OPPO is an outstanding piece of equipment it is most definitely not designed to be used as a standalone audio piece. To get the most out the OPPO it has to be setup to a monitor. I still can't figure out how to get it to play DVD Audio in stereo. Anybody out there tinkering with the same kinda stuff? Would be curious to hear your results.