peter hook yamaha basses

Those are all gorgeous. I love the body shape. Very distinctive, and serve a purpose of sustain.
What is the extra knob on the 2nd P bass ? It looks like a blend knob, but there's only one pickup. The 3rd bass is obvious.

@mb94952 2nd bass from left controls are:
Big knobs: vol, passive tone
Switch: passive/active
Small knobs: bass, mid, treble active eq

@hypercarrots OOooohh that is so cool.