Chuck and I have redesigned the control setup for the humbucker-equipped Fusions. The new Fusions are shipping with a push-pull pot instead of a blend pot.
Instead of being a blend pot, the fourth pot is now a separate tone pot for the Humbucker. Pulling this up adds an additional pickup to each switch position except the center (No. 3) position.
I have posted the new control setup in a graphic on a new tab on the Fusion page (I have also created similar diagrams for the various archtop models).
There are several reasons for this change. First, the push-pull allows us to include a larger number of different pickup combinations than the blend. Second, feedback has been that most players either turn the blend pot all the way up or down. The push-pull is quicker and simpler to use. Finally, since our volume controls are independent, users can duplicate all the effects of the blend pot in a simpler, more intuitive, way.
Rich