Pmbuko is right... the HK is playing the stereo compatibility track that comes on many SACDs (eg. DSOTM). Bet it still sounds great though.

As far as I know you can't play "real" SACD through the normal optical or coax digital links.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8