I was trying to do a test with an 88/24 audio file, but realized that my Early-2009 Mac Mini doesn't offer that as one of the audio output options, while my 2011 MBP does. So, since my mini is hooked to my Onkyo via a (relatively long) Blue Jeans Cable optical cable (and running fabulously), I decided I'd just unhook it and plug it into my MBP to test. Nothing--no sound, no response from the receiver. I started thinking that my MBP's optical out was broken (I've never tried it before), so I did a bunch of testing: Hooked to the Mini, with audio set to 48/16 or 48/24, it works just fine. Hooked to my MBP or my iMac (I drug it over to test), no sound, even with the audio set identically, and playing the same file. The optical outputs were definitely doing something, because if I disconnected the Toslink cable from the 3.5mm adapter, I could see red light coming out of the port, and the light went away when the sound was "sleeping" as well as when I pulled it out. So definitely doing something. Then I tried a crappy, ancient, 12-foot-long RadioShack cable I had laying around... and it worked properly. From both the iMac and MBP (couldn't quite reach the mini, and didn't want to extract it from the closet to test). Now, there's obviously a different chipset in the Mini compared to the other two, newer Macs, but I confess to being moderately shocked that a decent-quality cable that has worked well for two years completely fails when hooked to a newer Mac (only slightly newer in the case of the Late-2009 iMac). Is there something I'm missing here, or is the cable just of marginal length and the Mini has a stronger optical transmitter?