I'm looking for any good older amplifier that adjusts with sensitivity. In other words, 1 unlike my father's old amp which works but adjusts more like a manual transmission than an amplifier. The knobs go from 1 to 5 or 10 or whatever it is, and they go like "click" to the next number. They don't operate like the volume knob which can be set anywhere in between mute and wide open. Does this make any sense lol!