By the late 1960s, as electric guitarists in rock bands began using powerful amplifiers to play large venues, bassists needed to keep up. The Acoustic 360 was a "200-watt, solid state head designed to drive the 361 cabinet, a rear-firing 18” speaker enclosure". The engineers who designed the amp and cabinet in 1967, Harvey Gerst and Russ Allee, mounted the 18" speaker in a folded horn enclosure; the 360 amp had a built-in fuzz bass effects unit. The Acoustic 360 and its 361 cabinet "...got the bass world ready for the Woodstocks, Altamonts and giant festival concerts" and it was used by notable players such as funk bassist Larry Graham, Led Zeppelin's bassist John Paul Jones and jazz fusion player Jaco Pastorius. John Paul Jones used two of the amp/cabs in Led Zeppelin; Dave Brown used them with Santana; John McVie played with the amp/cab in the beginning years of Fleetwood Mac. In December 1967, the loud sound of the Acoustic 360 led to The Doors getting "...arrested for noise violations".