The Scarlett 3rd Gen Solo and 2i2 interfaces have just a few buttons to control the Air, Line, Phantom Power, and Direct Monitor settings. Mostly nothing that you can’t access from the front panel anyway.
Enabling Air will transform your recordings and inspire you while making music.
The Inst buttons are used to select between Mic/Line and Instrument level/impedance. When plugging in microphones or line-level equipment (such as a synthesizer, external preamp, or effects processor) to the input, set it to “Line”. The “Inst” setting is for instruments with pickups such as guitars.
Turning the “48V” switch on sends “Phantom Power” to the XLR microphone input(s). This is required for some microphones (such as condensor microphones), and damaging to some microphones (particularly vintage ribbon microphones).
Direct Monitor sends the analogue input signals to the analogue outputs for zero-latency monitoring.
On the 2i2, you have the choice of Mono or Stereo monitoring when you click the button. Mono sends both inputs to the left and right outputs. Stereo sends input 1 to the left, and input 2 to the right output.
By default, phantom power is turned off when the interface is turned on. This can be changed in the startup configuration (menu option View → Startup).
The one control not accessible from the front panel is “Phantom Power Persistence” (menu option View → Startup) which controls the Phantom Power state when the interface is powered on.