A treble booster is an effects unit used by guitarists to increase the high end of their tonal spectrum. Many units boost the overall volume as well. Treble boosters were commonly used by guitarists in the 1960s and 1970s. During the last couple of decades, their popularity has increased again and many clones and reissues of the classic circuits have become available.
Many treble boosters made in the 1960s were designed to not boost the signal much. Vox even decreased the output of the American made version of their treble booster because they were afraid that the signal would overload the amplifier's input stage.[1] Today, overdriving the input is considered one of the key features of a treble booster.
Popularized by guitarists such as Tony Iommi,[2] Ritchie Blackmore, Rory Gallagher, Brian May, and Marc Bolan,[3][4] treble boosters were used to overdrive amplifiers (mostly dark sounding, British tube models such as Marshall Bluesbreakers and Vox AC30s) in order to create a more distorted yet focused sound. They came up in the mid-1960s. By the 1980s they had fallen out of use. Guitarists used overdrive pedals instead, in a similar fashion. But the circuit and its derivatives have experienced a great revival in the 21st century, thanks to the many boutique builders who have rediscovered the circuit. While IC-based overdrive pedals remain far more popular than treble boosters, some players prefer the less compressed and more dynamic response of Rangemaster-family boosters.