On 08/02/2010 16:50, Rob wrote:
I've connected a Cambridge Dacmagic to a Mac Mini via the optical
connection, and I'm not sure which settings to select in the Apple audio
setup, for stereo playback through iTunes. It offers a variety of 2ch
settings with a variety of formats (44.1 - 96) and bits (16 - 24). They
all work, but I'd like the theoretical best setting, if there is one.

Whatever suits the bit rate and depth that is common between the
majority of media files played back. 16bit / 44.1kHz for things sourced
from CD (even as an iTunes download)

Though what happens if you replay audio snatched from a DVD? If you are
met with silence, you may have to occasionally reset output to 48kHz,
and remember to set it back afterwards - or just leave it at 48kHz and
hope that the internal circuits do a decent job of 44.1/48 resampling.

Only your ears can tell ...

--
Adrian C