The SA-15S2 has a nice warm tone and is very full sounding. It also has an optical input so it can be used as a standalone DAC. It only has single ended outputs though.
The SA-11S2 is a little more transparent and detailed, does NOT have an optical input, and has balanced outputs.
The SA-11S2 is a little more transparent and detailed, does NOT have an optical input, and has balanced outputs.