Hey, I do not notice any difference between the inputs... Can you tell me what the polarity switch is for? I think that might only be useful for people in the states because we have different sockets here... I haven't tried a bass but since the sound of the amp without the "treble switch" is pretty bassy, I imagine that also a bass sounds quite good. The inbuilt Tremolo makes a constant sound, a rhythmic chk-chk-chk even if you turn speed and intensity of the Tremolo down... Do you know how to fix this?