Got some news about 2.0 audio decoding you folks might find interesting.
I've got a Japanese HD DVD which has four audio tracks: PCM stereo, DTS 5.1 (96k/24bit), Dolby TrueHD 5.1 (96k/24bit) and DTS-HD Master Audio 5.1 (96k/24bit).
My XA1 is connected to a Pioneer VSA-AX10 receiver with both 5.1 analog and an optical cable. Did some testing, and here are the results:
PCM Stereo - sound from 2 speakers
DTS 5.1 - sound from all speakers
Dolby TrueHD - sound from all speakers
DTS-HD Master Audio - sound from all speakers
PCM Stereo - amp enters DPL II decoding mode (i.e. receives stereo audio)
DTS 5.1 - amp enters DTS decoding mode for 5.1ch output
Dolby TrueHD - amp enters DPL II decoding mode (i.e. receives stereo audio)
DTS-HD Master Audio - amp enters DTS decoding mode for 5.1ch output
Note: it clearly states DTS-HD Master Audio 5.1ch (96kHz/24bit) in the rear cover infobox.
I won't pay a cent for UHD Blu-rays made from 2K masters by upscaling.