We have an Onkyo TX-NR676E AV receiver and have recently signed up to Amazon Music HD. Using the integrated Amazon app, we tried playing songs that we know should be available in Ultra HD, however they're playing AAC files at 44.1kHz 16bit. I believe Amazon HD should play FLAC files at higher rates. I read on the Amazon website that it will always plays the best available audio quality that your device and network supports and that the Onkyo does support these higher rates. We tried changing the Listening modes but none of them appear to change the types of files played. Does anyone know if there are any settings we need to change in order for the built in Amazon app to play higher quality files?