eleven, believing that this numbering increases the highest volume of the amp. He explains, "It's one louder, isn't it?" This misunderstanding of the underlying operating principles led to the idiom "Up to eleven", also phrased as "These go to eleven". As a consequence of the film, real bands and musicians started buying equipment whose knobs went up to eleven. See also :Category:Guitar amplifier manufacturers Vintage musical equipment Tube sound Bass amplifier References Further reading Fliegler, Ritchie. The Complete Guide to Guitar and Amp Maintenance. Hal Leonard Corporation, 1994. Fliegler, Ritchie and Eiche, Jon F. Amps!: The Other Half of Rock 'n' Roll. Hal Leonard Corporation, 1993. Hunter, Dave. Amped: The Illustrated History of the World's Greatest Amplifiers. Voyageur Press, 2012. Pittman, Aspen. The Tube Amp Book. Backbeat, 2003. Tarquin, Brian. Guitar Amplifier Encyclopedia. Skyhorse Publishing, Inc., 2016. Weber, Gerald, "A Desktop Reference of Hip Vintage Guitar Amps", Hal Leonard Corporation, 1994. External links Lenard Audio History of Guitar Amplifiers (non-profit educational website) Amplifiers: What do all the controls do? Vintage Guitar magazine article on vintage amps Instrument amplifiers 01 Electric guitars Blues instruments Rock music instruments Folk music instruments Jazz instruments