Another scenario here that would be helpful with stereo in, dual stereo output routing would be to feed your stereo source into inputs 1/2 and have outputs 1/2 be a pass-through of your dry signal with outputs 3/4 being the output signal of a program. There would need to be delay compensation on the dry outputs of 1/2 of course, as to not introduce any phase issues seeing as there are often programs/algorithms-within-programs that are not 100% wet, and the dry signal within the “effected” path would be out of phase with the pass through on outputs 1/2 due to latency introduced by the processing of the effects.
