im unfamiliar with ibanez amps, i didnt know they made amps...:confused:, but anyways, im guessing by "boost" that is ibanez' way of saying "Distortion" or "gain", and of course its going to sound less plunky when you have distortion on, its because the distortion covers alot of the plunk up. thats one reason why there are so many crappy punk/metal guitarists.