Hi Damien, I appreciate your effort to solve this problem and I will be happy to contribute with information that might be useful to you since I prefer the sound of Audirvana compared to other players.
I also do think there is a SQ improvement with upsampling in Audirvana so the option with deactivation is not an alternative for me.
I’ve hade the same issue with two different MacBook Pro (Late 2008) 8 GB running 10.11.6. Both used exclusively for playing music with no other applications open.
I’ve tried both USB ports.
I’ve had the same problem with two different USB Dacs
Audirvana upgrade from 3 to 3.5 didn’t make any difference.
I’ve tried different settings with Max. memory allocated…
I’ve tried Direct Mode disabled, Integer Mode disabled and Exclusive Access disabled
So far the only thing that stops this issue is keeping upsampling Deactivated.
Anyone else having the same experience?
Roon with corresponding upsampling: No problems at all.