192 I/O + HD omni - latency offset

[Matt Hepworth]

1–2 samples is enough to cause comb filtering.

There was a post from AVID quite a wile back that listed the number of samples difference between RTL with HD series vs blue series. The RTL with blue series is 20 samples more at 44.1 and 50 samples more at 96. However, the recorded tracks should align because PT will compensate for it (it knows how much to compensate). The sound during tracking, however, will not be compensated, so the use of an aux master for the Omni channels with a TimeAdjuster plugin will compensate during recording and be bypassed for playback.

Also, you mentioned you'd be using the Omni for another 8 channel preamp. Omni only has 4 ins, unless you're talking about ADAT, but that would be an uncompensated AD from another unit, not the Omni AD.