that petrucci rig is pretty ridiculous... there are 5 amps in there, all of which are capable of making at least 2 separate sounds each. i've heard DT's live cds and seen them live 2 times back in 2000, and all of his lead sounds sound alike to me, sounds like he's just going for the saturated boogie lead sound, which he could get just from the mark IIc+ in his rack. he should take everything out ampwise except for the triaxis and the dual recto. (of course that pic is from an old rig ... god knows what hes using now)