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. For V2 we use a current balanced ECC83S for the phase inverter. The default power tubes are a matched pair of the JJ EL84's.