Linn AV Loudspeaker - Manual (Page 38)

Varying the gain
Switch 8 allows the gain to be varied with the control above the switches,
or bypassed if the preamp has a variable bass output level. Use this to set
the bass level for the system. Don’t be tempted to turn it up until it hurts!
Leave it fairly subtle. It is easy for the bass level to become overpowering.
Gain control Setting
Variable
1 2 3 4 5 6 7 8
Fixed
1 2 3 4 5 6 7 8
30
setting up the A
V
5150