Der verzerrt mit der Zerre von seinem Amp. Zu seinen Amps findet man folgende Information (irgendwo auf greenday.net):
Mainly plays through a modified Marshall amp. On Nimrod he used a Fender Bassman, a Hiwatt, and a Leslie. The amp he uses on Dookie is most commenly reffered to as the 'pete' amp and can be seen most noticably at the Woodstock concert, it has 'pete' written across it.
Billie say's a lot of his sound comes from strumming. "I use my thumb. It's that half-pick and half-thumb that gives it that thwack. Also, I don't play with my wrist, I play with my shoulder and hit it really hard."