I own the bass and have played it in the past.
as near as I can tell the small toggle switch has 3 positions. Up or down toggle engages the effects knob, lowest rotary knob. Middle position toggle , the effects knob has no effect.
It is possible to get a wah wah effects and weird stuff while rotating the knob but I suspect it was meant to be built in effects and you could pre set 2 different effects (up or down toggle)
I took mine into a repair shop years ago and the technician thought the set up was weird
Now if I could just get some nice tones going.
Bill
Austin, TX
