Applies to: all products
When selecting a Focusrite interface as the input and output device in System Preferences > Sound on Mac OS X, a message stating 'This device has no input/output controls' will be displayed at the bottom of the screen. In addition to this, the speaker icon in the Menu Bar will be greyed out.
This is normal behaviour - it's not possible to control the input gain or output volume from the Mac. Instead, the input gain must be adjusted from the gain dials and the output volume adjusted using the Monitor/Volume dial on the front of the interface.