Focusrite Scarlett 18i20 USB-C Audio/MIDI Interface (3rd Generation) - Manual (Page 11)

11
HARDWARE FEATURES
Front Panel
9 16 10 11 18 13
1 8 12 15 17 7 3
4 6 5 14
2
The front panel includes all the input gain and monitoring controls as well as two of the input
connectors for Mic, Line and Instrument signals.
1. Inputs 1 and 2 – Combo” type input sockets - connect microphones, instruments (e.g.,
guitar), or line level signals here. Combo sockets accept both XLR and ¼” (6.35 mm) jacks.
Microphones will normally be connected using XLR plugs: instruments and line level signals
should be connected via ¼” (6.35 mm) jack plugs of either TS or TRS type. The preamp gain is
appropriate for microphones when an XLR plug is inserted, and for higher level signals when
a jack plug is inserted. Do not connect anything other than a microphone - e.g., the output
of a sound module or FX unit - via an XLR plug, as the signal level will overload the preamp,
resulting in distortion; also, if phantom power is enabled, the equipment may be damaged.
2. 48V – two switches (1-4, 5-8) enabling 48 V phantom power at the XLR contacts of the Combo
connectors for mic inputs 1-4 and 5-8 respectively. (Note that inputs 3 to 8 are on the rear
panel.) The switches each have an associated red LED indicating that phantom power is
selected.
3. Gain 1 & 2 – adjust the input gain for the signals at Inputs 1 and 2 respectively.
4. INST – two switches changing the input configuration for the jack contacts at Inputs 1 and
2. When INST is selected, the gain range and input impedance are altered (relative to LINE),
and the input is made unbalanced. This optimises it for the direct connection of instruments
(usually via a 2-pole (TS) jack plug). When INST is off, the inputs are suitable for the connection
of line level signals. Line level signals may be connected either in balanced form via a 3-pole
(TRS) jack or unbalanced via a 2-pole (TS) jack. ‘INST’ illuminates red when Instrument mode
is selected. Note that INST may also be selected from Focusrite Control.
5. AIR – eight yellow LEDs indicating selection of AIR mode for each channel. AIR mode, selected
from Focusrite Control, modifies the frequency response of the input stage to model the
classic, transformer-based Focusrite ISA microphone preamps.
6. PAD – eight switches selecting the PAD function for each channel. PAD decreases the signal
level going to your DAW by 10 dB; use when the input source has a particularly high level.
‘PAD’ illuminates red when active. Note that PAD may also be selected from Focusrite Control.
7. Gain 3 to 8 – adjust the input gain for the signals at Inputs 3 to 8 respectively. (Note that the
connectors for these inputs are on the rear panel.)