How would I do a 'loop back' test in Samplitude?The same as any DAW.
Send a signal out on 1 and bring it back on 2.
The two signals should "line up" perfectly.
When using ASIO drivers the host should do this automatically.
With WDM drivers you have to set the "compensation" manually.
This is the "25 words or less" explanation.
There was a very lengthy thread
here years ago.
Be forewarned, it'll take a day or two get thru; IIRC.
T