The idea is that you use your Blu-ray player just like a CD player. No need for a screen. So far, so good. You select the type of output with the coloured buttons on the remote control. Trouble is that my Sony BDP-S350 blu-ray player (or the disc) defaults to the DTS 5.1 soundtrack and I get a frighteningly loud buzz, followed by silence. Selecting the PCM output gives great quality sound, so I am happy with that.
I am listening in stereo, so don't need the DTS track. I will have to investigate if it is possible to set the Sony default to PCM and to somehow prevent the loud buzz from the DTS output.
Please note, that this problem may be due to my player, rather than the disc. Trying to play the audio from normal Blu-ray discs is a nightmare with this Sony player (and probably with most others), as the Sony's home screen interface looks like a 5-year old kid designed it after looking at a 1980's ping-pong tennis screen. Pitiful is the only way to describe it.
The Pure Audio concept works! There is still the usual long delay whilst my Sony Blu-ray player gets itself ready to play the disc, but this is the fault of the player rather than the disc.