The LED at the bottom of the module indicates the mode that the AUX1 is in. Internally, there are headers that allow you to switch the jacks from the MX2 Stereo Mixer's busses to the MX5.1 Surround Mixer's busses, since any combination of modules can be used at the same time in the rack.
Product DescriptionThe Tonelux AUX1 is a simple BUS access module that allows the user to insert an additional mixer, mic pre, etc. into the Tonelux MIX BUS. Each input is BALANCED and is calibrated for a level of +4 dBu