Treble booster

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. Today, overdriving the input is considered one of the key features of a treble booster.