American doom/drone metal/dark ambient band, formed as a tribute to Earth (2) (and named after this band's amplifier brand of choice). The two members are also active in various other bands (Khanate, Goatsnake, Burning Witch). Sunn O))) have employed a number of high-profile guests along the years such as Attila Csihar, Julian Cope, Malefic (2), Oren Ambarchi and Merzbow.