Hi, I recently purchased a Radial X-Amp with high hopes on reamping.

I connect my X-Amp to the guitar amp and no noise... all is good,
then when I plug into the X-Amp's input from the Fireface's out (TRS>XLR) I get huge hum noise.
Thats when the ground lift is engaged, when its not it sounds like a jet engine.

I am interested in this for re-amping jazz guitar (archtop). I DI with an Avalon U5 and use a reflexion filter with mic to mic up the guitar acoustically. I like the idea of not having an amp in the same room so I can record the pure sound of my archtop although would like to add my Polytone miced up into the mix.