[quote name='zero9' timestamp='1419937140' post='2644043'] 
Surely, the line and inst switches don't apply to a microphone, when using an xlr. 
[/quote] 
 
No, the switch doesn't affect the mic inputs. From the manual: 
 
"Note the Scarlett 2i2 has no “Mic/line” switch – the Focusrite preamplifier stage is automatically configured 
for a microphone when you plug an XLR into the input, and for a line or instrument when you connect 
a jack plug" 
 
The mic channel max gain is shown as 46dB. 
 
I sympathise as I have a Lexicon Lambda with 44dB of mic gain