Hi, I have a late 2013 27" iMac with a fusion drive. Every time I connect a USB audio device the iMac ends up freezing after a few minutes. It seems to be a problem for all 2013 27" imacs with fusion drives and some people also experience crackling sounds. I used to follow a discussion on the apple support communities but that page hasn't been updated in a long time: https://discussions.apple.com/thread/5479208?tstart=0 So would like to ask if anyone who has experienced this issue knows if Yosemite has fixed the problem. I can't find any comments on the internet that mention anything. Thanks!