Plex Media Server version?
Plex Android TV app version?
There was an issue with audio transcoding to stereo when the app was set to Optical. It was addressed in 8.25.0. The current version is 8.25.1.
Check the version installed on your Shield and update if necessary.
See Authorized Devices for a list of servers, clients, and their respective versions.
There is no need to do this. The Shield and Sony receiver exchange capabilities via the HDMI interface.
The Optical setting is meant to emulate a connection via an optical cable. It is useful when the Shield is connected to a TV input via HDMI and the TV is connected to a receiver/soundbar via an optical or coax cable.
When set to Optical, the output will behave as an optical output. The supported audio formats are AC3 & dts at 5.1 or fewer channels and PCM 2.0. Other formats will be transcoded.
- Set the Shield audio back to Auto.
- Update the Plex app to 8.25.1 if on an earlier version
- Set the Plex app to Passthrough = HDMI.
AC3/EAC3/dts/dts-HD should direct play and passthrough to your receiver.
AAC 5.1 (or fewer channels) should pass to your receiver as multi-channel PCM.
The specifications I see online do not list TrueHD as a supported audio format for the STR-DN840 (Sony website).
If TrueHD is not supported by the receiver, it will be transcoded by the Plex Media Server to a supported format. At one time TrueHD was transcoded to EAC3. However, it may now be transcoded to OPUS. I do not know what format will be passed from the Shield to the Sony receiver.
In any event, you should receive multi-channel audio for both AAC 5.1 and TrueHD 7.1/5.1.
