The analog is important in this case because of the audio formats supported by the BDP-83 that cannot be output over coaxial or optical. In addition to DVD-Audio (which gets downmixed to stereo) and SACD (which is restricted from any digital output over coaxial and optical), there are three lossless audio formats available on Blu-ray (uncompressed PCM, Dolby TrueHD, and DTS-HD Master Audio) that require more bandwidth than coaxial and optical provide. Multichannel PCM gets downmixed to stereo for coaxial, while TrueHD and DTS-HD MA either get downmixed to stereo or use a lossy (Dolby Digital or DTS) "core" track depending on how the player is configured. For those five formats, the multichannel analog is the "purest" option.