I read a couple of things from their website that all seemed to indicate that two-wire was the only way, like this on the product page:
The DAC1-MK2
The DAC1-MK2 is similar to the DAC1 except for the sampling frequency range it can accept. The DAC1 works at 44.1 / 48 / 88.2 and 96kHz, while the DAC1-MK2 can handle 176.4 and 192kHz in addition.
176.4 or 192kHz signals must be connected to inputs 1 and 2 of the DAC1-MK2 in the two wire AES/EBU format. (The left channel goes to input 1, the right channel to input 2). If a valid two wire 176.4 or 192kHz signal is connected to the DAC1-MK2 and input number 1 is selected, then the unit will automatically detect such a signal and will light both input 1 and input 2 selection switches.
DAC1 units can be upgraded to DAC1-MK2 by swapping two chips inside the unit.
And then I saw this from the same manual you quoted (even though I missed the part in your post):
For dual wire scheme signals (88.2 up to 192
kHz) the two channels are connected as follows:
Left channel to input 1, Right channel to input 2.
To activate, press the input 1 key. If such a signal
is present at the input of the DAC1-MK2, the
software automatically detects that and switches
the D/A accordingly. Also both input 1 and input 2
keys are lit. If you press the input 2 key with such
a two wire signal present at inputs 1 and 2, the
DAC1-MK2 interprets the signal at input 2 as a
normal two channel AES/EBU signal. I.e. do not
select input 2 when feeding a two wire signal.
That one portion of the manual would seem to contradict the product description, which seems odd but is preferable of course. How much is thie mk2?