Thanks that makes sense now, but I still don’t get why you need bitperfect output, especially as you say most of the music you’ve been listening to has been through iTunes and therefore I assume compressed (although you say you’re moving to flac now). So do you perceive an actual quality difference between bitperfect playback and resampled/upsampled playback? Also, are you sure that just because the R6 Pro/DX220 support ‘system wide bitperfect’ that the apps you mention are actually delivering bitperfect output? I’m not so sure that’s the case, especially if you’re sideloading APKs. I’m not at all convinced that an app - mediamonkey for example - will sound any better on the iBasso or R6 Pro than it does on the M11 just because of bitperfect output.