Thanks Currawong; good idea. Since I was pestering Audio-gd anyway, I asked them about the DAC19; here's Cherry's response:
"Due to large order, DAC-19MK3 can be ship during May,we can't very sure the shipping time."
A later response from Kingwa regarding the C2C:
"You are right, it is effect SQ. Because the C2C design not practicable HP/preamp relay in the PCB, so if you need preamp output, it need add a switch, and this switch must on the panel can let the connect wires short, but the panel not any spare switch can do this function, unless you put the input selector on the rear, then add the HP/preamp switch on that place."
So the C2C can be made to function as a preamp (just not with the type of relay used in the Compass), with a loss in sound quality, but the input selector switch would move to the rear panel in order to keep the connection short (and reduce the effect on sound quality). Now I just have to decide if I'm really ready to make this kind of investment...