From the manual
MAIN OUTPUT (1)
These are your main stereo outputs. Use these outputs to connect to a mixing desk in a recording studio, or to the front-of-house mixer in a live situation. These outputs deliver the entire Rig: Amp, Cabinet, and all Effects. You have a choice of XLR (balanced) or quarter-inch TS-jacks (unbalanced). The XLR outputs are protected against 48V phantom power fed by a mixing desk. However, you should avoid feeding phantom power into the PROFILER if you want the best audio quality. Like all inputs and outputs, it offers a ground lift to prevent a loop hum.
MONITOR OUTPUT (2)
Use this mono output to connect the PROFILER to a stage monitor with its own level controls. This output also has its own ground lift.
You can also connect this output to a power amp and a regular guitar cabinet. In this case, you need to switch the cabinet simulation off, using the soft button “Monitor Cab Off” in the Output Section, to prevent the unwanted coloration that would result from running a speaker emulation through a guitar cabinet.
Bypassing the cabinet module can also be done by simply pressing the CABINET button. However, there are two differences compared to enabling “Monitor Cab Off”:
• Bypassing cabinet is an individual setting to each Rig, unless you lock the cabinet module in its “off” state. Monitor
Cab. Off is a global setting. • It will bypass the cabinet module for all outputs, whereas "Monitor Cab Off" will only affect the signal routed to the MONITOR OUTPUT (and the built-in power amp of PowerHead and PowerRack).
✓ If you select the option “Monitor Stereo”, MONITOR OUTPUT and DIRECT OUTPUT become one logical pair of stereo outputs. Functions like Monitor Output Source, Monitor Output Volume, Monitor Volume Pedal, Monitor Output Link, Monitor Cab. Off, Monitor Output EQ, and Aux In > Monitor are applied to both outputs automatically.
so that said......because your running into a real cab (with its own flavor) you can disable the cab that is designated in a specific profile so you don't get the stacking of two cabs...one simulated and one real..... cool