Hi. I have the Oppo 203 and just received Arc. Due to DTS issues I previously had a 2x1 Toslink Audio Switch that I could toggle to play DTS movies in Dolby 5.1 from the Oppo.
Other than using the Optical adaptor and manually swapping the HDMI cable everytime I watch a movie in DTS any other suggestions on settings on the Oppo player that will limit output from HDMI cable to Dolby 5.1.....there's no obvious menu selection on the HDMI output settings. TIA