He used to use 5150's. Has used a pod before. I think he is using mesa boogie and the moment. Think it is a roadking.
Not sure what else he uses.
By virtue of their electrical properties, tubes generate a special waveform when they're saturated, which is why tube engineering has tremendous tonal advantages over solid state or DSP solutions, particularly for crunch and lead sounds. Tubes enter the saturation zone gradually or softly, which lends tube-driven tone its trademark yet totally unique character.