The tone and gain comes from the dual-cascading tube preamp!
The Marshall AVT150 4-Channel Combo Amp with DFX is one loaded combo: 4 channels; 150 watts of power; and 2 separate, 16 digital effects sections! The tube preamp drives the Clean, Overdrive 1 and Overdrive 2 channels with an added acoustic simulator channel (makes any electric sound like an acoustic). Because all 4 channels are footswitchable (switch included), this Marshall amp gives guitarists ample versatility on stage. 2 digital effects sections enhance this flexibility. One section is dedicated to the clean and simulator channels, the other to the overdrive channels. All effects are tweakable via mix, adjust, and select knobs; and are on/off footswitchable. With 150W driving a Celestion 12" (custom-designed for the AVT series), this amp cranks without losing focus.