Has anyone tried using the USB input as a remote speaker from I-Tunes on a Mac. I am considering purchasing a 990, but have a lot of music on my mac and would like to know if this would work as it is much better solution than the audio out cable from a computer.

I haven't heard of anybody trying it. Would you be tying it to an Airport Express? If so, I don't think that the USB connection will work - the best bet with an Airport Express would be an optical digital audio cable (the little analog audio output also has a mini-optical connection hiding in there).

If you were talking about just connecting from the computer to the 990, it'd work just fine on a PC but I don't recall if folks have been able to connect with a Mac or not. I suspect that somebody around here has tried that, at least, and while firmware updates can't be done that way (unless you run something like Boot Camp to get into Windows) I guess it's pretty likely that a Mac would recognize the USB connection as an external audio device.

I've used the 990 with my mini via USB. It works just fine, but the optical cable has at least one advantage. Dolby Digital and DTS will NOT be passed over the USB cable. So if you use your Mac as a DVD player/media center then the optical cable is a better choice.

I know for a fact that Linux recognizes it as a sound device. Tested it with my laptop running Mandriva, kernel version 2.6.11-6mdk, and KDE 3.3. I 'd have to agree with gonk that it should work on a Mac as well.

Thanks! Sounds like the consensus is that it will work fine.