If you set the 1070 to 7.1 Direct and the mains and center were silent, I'd double-check the multichannel analog cables and make sure they're all plugged into the right places.

For SACD and DVD-A, you of course need the 7.1 Direct input. SACD in particular will send no audio via digital connection; DVD-A will send a downmixed stereo signal.

For DVD's and CD's, you are probably best off using the digital connection. If you are having any problems there, you need to make sure that the DVD player's digital output is set to "bitstream" (sometimes called "raw") and not "PCM."