Have hooked up my 2105 with HDMI directly to TV; perfect performance.
Additionally, have hooked up audio coax output from Bluray to an (AC/DC powered) audio converter with RCA outputs to a Sony DAV-DX355 home theater system (circa 2007). Only sound output when playing DVD audio through the home theater is a distorted "motorboating" sound that will respond to volume control only. Have cycled through all of the audio formats on the 2105 with no change in sound effect.
Thanks for your help.