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, two standard ECC83S's for V2 and V3, a balanced ECC83S for the phase inverter in V4 and a matched quad in a warmer grade of JJ EL84's for the power section.