584.4 USING THE GRAPHICAL INTERFACEVOLUME CONTROLThe following volume control options are available within the graphical user interface.A Mute button also allows you to mute all audio outputs of the SDP-75.A Dim button also allows you to decrease the volume by 20dB.NOTE: By default the last used volume is recalled at start-up.SOURCE SELECTIONSources can be selected through the graphical user interface by clicking on the icon:Figure 38: The source selection page in the graphical user interface