There is NO player out there that can pass SACD over optical; you are getting sound because it is being passed as PCM and via optical you will only get 2 of the 6 channels. In the PS3 there should be a setting for SACD priority: CD, 2CH, or Multichannel. If you don't set it to multichannel, it won't play multichannel.
The PS3 can pass it via analog (stereo only also) and HDMI, and only certain models can play SACDs.