If I remember rightly there have been others with McIntosh Amps having similar issues with its usb dac and Roon. I have to say this is the first one to say Qobuz app sounds better though. Personally always found the apps from Qobuz and Tidal to be quite poor in comparison. I wonder if the differences.come from a different route for flac to pcm conversion? Roon will.onky forward on pcm direct, whilst Qobuz app will output flac and the amp has to do the decode.?