Did a quick search, there is this thread which is not really OT enough for me: https://www.head-fi.org/threads/macos-users-what-player-with-eq-and-flac-do-you-recommend.869534/ https://www.head-fi.org/threads/roon-vs-amarra-vs-audirvana-on-mac.879439/ <neither are specific to what I'm looking...

Just bought a E11, was said they could drive a HD800 as well as the HE-500 as said on headfonia, and I think my searches of head-fi turned up some mixed opinions on whether or not the E11 could drive the HD600/650   http://www.headfonia.com/fiio-e11-portable-amplifier/    ...