Here is a diagram of the controls on my Yamaha TRBX504.
90%+ of the time I play in the Passive mode.
I have a question for you:
Am I correct in thinking that in the passive mode the Mid Boost and Bass Boost knobs are completely inactive and the tone is controlled completely by the position of the Master Tone knob, and if so, does rolling the knob clockwise increase the Bass frequencies response while counter-clockwise cuts them?