It's no secret that Stevie played his amps cranked and preferred a little cleaner sound from the front end allowing you to hear more power tube breakup. This kit uses a JJ 5751 for V1 which is in-between an ECC81 and an ECC83S in gain, a balanced ECC83S for V2 and a warmer grade of JJ EL84's for the power section. A real nice combination!