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 along with two ECC83S's with one being current balanced for the phase inverter in V3 and an EZ81 rectifier tube. The default power tubes are a matched pair of the JJ EL84's but you can configure this kit to use the JJ EL844's to drop the power output a couple decibels by clicking on the "Customize" button!