The GB2 is an addition to the Soundcraft GB Series, featuring 4 group busses configured as 2 stereo subgroups and an integral 6 x 2 matrix.
The GB2 features two stereo input channels, with separate mic and line inputs. In normal use, the mic inputs are routed to the local channel and the line inputs act as a stereo return to the mix bus. Selecting the LINE input to the local channel overrides the Mic inputs.