Hi All,
really stuck on this, I'm trying to use my x3 just for effects only and have connected the direct out to the fx return of the x3 and fx send into return I put of the kemper, mix on the loop is 100% but can't get any sound! please guys any ideas? 
i think fx send on x3 is wrong, try main out or similar
fx loop of kemper: direct out = send, return = return 
So you need to connect "direct out" (Kemper) to GUITAR IN of X3 and OUT/MONO of X3 to return (Kemper). Try this first, this way you have all effects in the loop.
If you want to use 4-cable-method, we talk again.
I believe that you need to connect the Direct Out from the KPA into the input of the X3, then connect the output of the X3 to the Return of the KPA.
