If you are playing bass sample loops, you should go through your amp or split off to a separate amp. Trying to go straight to the PA sounds like a nightmare. We have enough trouble with sound guys just getting our bass to sound right
The fuzzy/noise sounds like a gain issue. I would try lowering the input gain and raising the master volume to get to unity gain (or vice versa, not sure how the XL gain staging is structured). Just to double check, you're using the Instrument input? And going from the output jack to the next pedal?