Which is ultimate-er? Leica M (240) and Astell & Kern AK240 June 10, 2014 in digital players The Leica M (model 240) looks nothing like the Astell & Kern AK240, and it appears to lack optical output, not to mention support for DSD audio files. No matter. There must be a connection somewhere. I'm doing my damndest to suss it.