 Treble booster

A treble booster is an effects unit used by guitarists to boost volume and especially the high end of their tonal spectrum, and was popular mostly during the 1960s.Popularized by guitarists such as Tony Iommi, Ritchie Blackmore, Rory Gallagher, Brian May, and Marc Bolan, 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.