I am in the process of buying an HD500, have question before I do that though. The physical (drive, bass, presence, master, etc...) all control the amp of the individual preset that you have (I believe). When you are editing an amp in your preset, do you change these parameters for the preset or do the knobs apply to every amp within every preset? Example, preset 1 uses amp A with the physical bass knob at +6. Will preset 2 with amp B also have the bass set to +6? And when it's changed to +4, will that also affect all the other amps within presets? Thanks in advance!