Did you know there is a jumper in the 24i that allows you to control the main outputs of the 24i with the volume knob on the front panel? The default is that the volume knob only controls the headphone outputs. There are instructions printed on the circuit board inside of the 24i, right next to the headphone outputs. It only requires powering down the unit, removing the cover, and simply moving a plastic jumper from one set of pins to another.