The 568 does not have any analog pre-amp capabilities. It digitizes all of the analog inputs. Therefore, a high end CD player (via its analog outputs) would be a waste with a Meridian 568. The 568 only supports single ended analog inputs anyway.
On the flip side, the 568 is a pretty decent DAC. Feeding the 568 with a good digital signal, either via SPDIF, or via proprietary Meridian Link, is the way to go.
It's not really possible to make direct comparisons between the 568 and the 861. They are different architectures, at different price points, with different functional capabilities. They are both excellent performers.
On the flip side, the 568 is a pretty decent DAC. Feeding the 568 with a good digital signal, either via SPDIF, or via proprietary Meridian Link, is the way to go.
It's not really possible to make direct comparisons between the 568 and the 861. They are different architectures, at different price points, with different functional capabilities. They are both excellent performers.