Probably an easy question to answer. I'm running 5 analog cables from my Oppo CD player to my Emotiva processor for CD play. Is there a certain mode to use-PLXII or DD or will it automatically choose? I want to hear the full range of my SACDs. I don't even understand the difference between running these cables or running an optical cable for the sound.

Not sure about your SACD player. Mine (a Denone 3930CI) does not output multichannel through HDMI or optical cable. To play multichannel SACDs, I have to switch to "Multi Channel" of my receiver which in effect takes all those PLXII or DD out of play. The best is ask Oppo or it's users of help.

I've got the Oppo 980 and SN R-771 Rx and am running 6 analog RCA (incl sub). You have to set up the Oppo to default to multichannel output for SACD or DVD-A play in the menu. Then you set the Rx to the External input. It does no processing at all, just a straight feed from the source.

You can't run through optical due to piracy paranoia (optical has no HDCP capability, and taping from analog is seen as less devastating to the industry).

You won't be using PLII or DD when you're listening to SACD or DVD-A, unless your processor does bass management and expands the channels out to 7.1 using PLII.

In order to use the audio processor’s bass management or Matrix to the surround back channels from a 5.1 source, the audio data stream needs to be digital. When you use the source analogue outputs, the audio processor is receiving analogue data, not digital. HK is the only manufacture I am aware of that will convert analogue to digital and then back to analogue. Unless you have an HK that will do this back to front to back conversion, you will have to use the source bass management functions. You should then be able to apply whatever bass management and channel levels that the 980 allows.

There is another option, but only if you have an audio processor that is HDMI 1.1 spec or higher. You output to the audio processor as multi channel digital PCM via HDMI from the source. The audio processor will then recognize a multi channel digital input and you will be able to apply bass management to that data stream. If you have an audio processor that has HDMI 1.2, and it accepts and recognizes the SACD compressed DSD format, you select an output of Bitstream via HMDI and audio processor will unpack the compressed DSD digital data stream, allow you to apply bass management to it, and then convert it to analogue.

Clear as mud??

The Dolby modes are a compression scheme (sort of like MP3) to allow the space for the 6 channels (5.1) of audio to fit on a DVD. With SACD or DVD-A the audio isn't competing with the disc space for video; compression is not used and so there is no need to set your receiver to these modes.

Each of the six audio channels is outputed from your players analog 5.1 outputs as un-compressed PCM audio. So you can set your receiver to 5.1 analog or bypass mode to hear the audio as it was recorded, without further processing or changes necessary.

As Mike pointed out, with this setup your receiver typically does no bass management so you will need to setup your speaker sizes (Large vs. Small) and crossover for the sub in the player.

Just make sure to set your player for multichannel out (SACDs can also output as a standard 2 channel CD), and that your receiver is using the multichannel input as well. If you aren't sure the sound is coming through the 5.1 cables vs. the optical, you can temporarily disconnect the optical to ensure you are using the signal path you want.