I was right. That was a Friedman Brown Eye in Mastodon’s rehearsal studio video, stacked up with the band’s Marshalls and Mesas. It seems that guitarist Bill Kelliher caught Alice in Chains using a Friedman and thought, “I’ll have what he’s having.” For little boutique amps those Brown Eyes are sure gaining mind share with the bigger touring acts. Cynic and Periphery have been using the Brown Eye model in their Axe-FX units.
All this info and more can be found in the video that Dunlop just uploaded, in which Bill is interviewed about his rig and the forthcoming album that it was used to record. I was surprised to hear that he has a T.C. Electronic G-System for his delays, modulation, and channel switching. They’re great pieces of hardware, but Mastodon always struck me more as pedal types than multi-effects users.