[Ron Ramirez]

The individual capacitors add together as they are switched into the tone control circuit. In the first position (Brilliant), none of the capacitors are in the circuit. In the second or "Bright" position, the .015 uF is switched in. In the third or "Mellow" position, both the .015 and the first .01 are paralleled together (.015 + .01 = .025 uF). And in the fourth or "Deep" position, all three caps are in the circuit, paralleled together (.015 + .01 + .01 = .035 uF).