Focusrite Scarlett 18i20 User Manual page 22

Instrument Inputs
Frequency .Response
Dynamic .Range
THD+N
Maximum .Input .Level
Gain .Range
Line Outputs 1 to 10
Frequency .Response
Dynamic .Range
THD+N
Maximum .Output .Level .(0 .dBFS)
Headphone Outputs
Frequency .Response
Dynamic .Range
THD+N
Maximum .Output .Level .(0 .dBFS)
22
20 .Hz .to .20 .kHz, .+0.5/-1.5 .dB
109 .dB .('A'-weighted)
< 0.003%
+12 .dBu
50 .dB
20 .Hz .to .20 .kHz, .+/-0.5 .dB
108 .dB .('A'-weighted)
< 0.001%
+16 .dBu, .balanced
20 .Hz .to .20 .kHz, .+/-0.5 .dB
108 .dB .('A'-weighted)
< 0.001%
+13 .dBu