Some advice as I use a hd500x live to a desk. Firstly test it out in the rehearsal space if possible just to make sure you cut through the mix in a live situation against the gear the rest of your band is using. Another thing (I do this) is set up dual amps. One is (L) to the desk with the full amp, the other ® is the preamp version into a poweramp pedal (ehx 44 magnum) then to a quad box on stage. This is just used as my own monitor and not mic'd. Can't always trust you will have a decent foldback. I don't bring a quad box but if there is one on stage, it's some extra insurance :-)