Question Can the ADAT input of the BMC-2 be used as a second TOS input, or do I need to use an upstream switcher  Answer This is unfortunately not possible: the ADAT input can only receive ADAT signals and cannot be switched into a TOS input.  On the other hand, the ADAT input can be fed with 2 stereo signals, and you can select between channels 1-2 and 3-4.