My Blu-Ray HDMI conundrum

A few months ago replaced my analog multi channel preamp (McCormack MAP-1) with an upgraded Onkyo 855, and went all multi channel digital. I did so because the Onkyo produded glorious multi channel SACD sound with my Sony XA 5400 CD/SACD player over HDMI (far better than what I was used to using the McCormack). However, for some reason, using the Onkyo with my Denon 2500 Blu Ray transport over HDMI is a big dissapointment on the audio side of things (video is stellar). Although I cannot do an A/B (Denon has no analog outs), I suspect the analog route would sound better on Blu-Ray. I could ditch my Denon 2500, get a player with multi channel analog outs and run multi channel analog through the Onkyo. I could get a Denon Pre/Pro and run high rez digital through the proprietary Denon Link (an expensive proposition). I could get my Denon 2500 upgraded. I am looking for any advise on how to get better audio out of blu ray.