Scarlett 18i20 3rd Gen specifications – Focusrite User Guides

Performance Specifications

Where possible, we measure all performance figures following AES17.

Configuration
Inputs	18: analogue (8), ADAT (8), S/PDIF (2)
Outputs	20: analogue (10), ADAT (8), S/PDIF (2)
Mixer	Fully assignable 18-in/10-out software mixer (Focusrite Control)
Custom Mixes	12 mono
Maximum custom mix inputs	24 mono
Supported sample rates	44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz
Microphone Inputs
Dynamic Range (A-weighted)	111 dB
Frequency Response	20 Hz to 20 kHz ±0.1 dB
THD+N	< 0.0012% (minimum gain, -1 dBFS input with 22 Hz/22 kHz bandpass filter)
Noise EIN (A-Weighted)	–128 dB
Maximum Input Level (at minimum gain)	+9 dBu (no PAD); +16 dBu (PAD selected)
Gain Range	56 dB
Input Impedance	3 kΩ
Line Inputs 1 to 8
Dynamic Range (A-weighted)	110.5 dB
Frequency Response	20 Hz to 20 kHz ±0.1 dB
THD+N	< 0.002% (minimum gain, -1 dBFS input with 22 Hz/22 kHz bandpass filter)
Maximum Input Level (at minimum gain)	+22 dBu (no PAD); +29.5 dBu (PAD selected)
Gain Range	56 dB
Input Impedance	60 kΩ

Instrument Inputs 1 and 2
Dynamic Range (A-weighted) Dynamic Range	110 dB
Frequency Response Frequency Response	20 Hz to 20 kHz ±0.1 dB
THD+N THD+N	< 0.03% (minimum gain, -1 dBFS input with 22 Hz/22 kHz bandpass filter)
Maximum Input Level (at minimum gain) Maximum Input Level	+12.5 dBu (no PAD); +14 dBu (PAD selected); measured at minimum gain
Gain Range Gain Range	56 dB
Input Impedance Input Impedance	1.5 MΩ
Line Outputs 1 to 10
Frequency Response	20 Hz to 20 kHz ±0.1 dB
Dynamic Range (A-weighted)	108.5 dB
Maximum Output Level	+15.5 dBu (balanced)
THD+N	< 0.002% (-1 dBFS input with 22 Hz/22 kHz bandpass filter)
Output impedance	430 Ω
Headphone Outputs
Dynamic Range (A-weighted) Dynamic Range	104 dB
Maximum Output Level	+7 dBu
Frequency Response	20 Hz to 20 kHz ±0.1 dB
THD+N	< 0.002% (measured at +6 dBu with 22 Hz/22 kHz bandpass filter)
Output impedance	< 1 Ω

Analogue Inputs 1 & 2
Connectors	XLR Combo type: Mic/Line/Inst, on front panel
Mic/Line switching	Automatic
Line/Instrument switching	2 x front panel switches or via Focusrite Control
Pad	10 dB attenuation, selected per channel from Focusrite Control
Phantom power	Shared +48 V phantom power switch for inputs 1 to 4
AIR function	Selected per channel from Focusrite Control
Analogue Inputs 3 to 8
Connectors	XLR Combo: Mic/Line, on rear panel
Mic/Line switching	Automatic
Pad	10 dB attenuation, selected per channel from Focusrite Control
Phantom power	Shared +48 V phantom power switches for inputs 1 to 4 and 5 to 8
AIR function	Selected per channel from Focusrite Control
Analogue Outputs
Main outputs	10 x balanced ¼” TRS jacks on rear panel
Stereo headphone outputs	2 x ¼” TRS jack on front panel
Main monitor output level control	On front panel
Headphones level controls
Other I/O
Optical I/O	4 x TOSLINK optical connectors; 8 channels @ 44.1/48 kHz or 4 @ 88.2/96 kHz
S/PDIF I/O	2 x phono (RCA) or via Optical I/O (selected via Focusrite Control)
Word clock output	BNC connector
USB	1 x USB 2.0 Type C connector
MIDI I/O	2 x 5-pin DIN sockets