My testing showed using the “Dir” option in the mixer does not add any latency, but does cause about +30º phase shift at 12kHz… Which is odd because if it’s not adding latency it must be before the converter… possibly some sort of aliasing filter on the input?
Also even going via “Direct”, if you turn on Trk 8 as “Master” latency increases by about 0.75ms.
EDIT: Sorry, I just went back and checked my measurements. My mistake. latency on the “DIR” mixer was +1.29ms compared to the cable loop, so yes DIR must be on the other side of the converter. (Phase shift and additional latency from Trk 8 Master still appears to be correct though)
Thanks Avantronica for making me second guess that.