Blender is a flexible mixer module with 3 crossfaders. There are AB (X-Fade) crossfaders that can control the fade with CV, and 1-2 and 3-4 crossfaders that can be controlled only by the knob. Each of these has two inputs and one output,The outputs of the 1-2 crossfader and 3-4 crossfader are internally connected to the two inputs of the AB crossfader.. In this state it can be used as a nested crossfader. This internal connection will be cut if you patch the A or B input jacks.