My Oppo was reset to factory (somehow) just before I got my M80s and I couldn't figure out why there wasn't any sound coming from the surrounds on a DVDA. Turns out the Downsampling was set to stereo (and the sub to No). The music still sounded great.

I gather the Hitachi DS is for 96khz material. I'd set it to off. Also, leave the default bitstream for DD and turn on bitstream for DTS.

M80s/VP160/QS8s/EP350; M22s; M3s.