You can set the EXP jack on Iridium to accept an expression pedal to act as a volume pedal that is placed either right before the amp modeling, or right after the IR cabinet, but before the ROOM ambience in the pedal’s internal signal routing.
***By default, Iridium’s EXP jack is set to Volume PRE mode from the factory.
To set the EXP jack to Volume PRE mode:
To set the EXP jack to Volume POST mode:
NOTE: EXP jack assignment persists through power cycles.