Hi, I have the above amp/receiver, great for the office running Dali Zensor Pico's. I want to get the best sound out of it, I am just confused at the Hi-Res status. I am presuming inputing a Hi-Res feed means digital and the only digital input is Bluetooth. Is Bluetooth the best way to go? My main listening is through Spotify, and I have an old iPhone which I use on Very High Quality setting which I believe is better than through my Mac Mini which is only High Quality. Would an external DAC to analogue phono input be better? Cheers!