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 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 boutiquebuilders 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.
One of the earliest treble boosters was the Dallas Rangemaster. Unlike most of today's clones, the original Rangemaster was not a pedal, but a box meant to be placed on top of the amplifier. The circuit makes use of a single OC71 or OC44 germanium transistor. The Rangemaster has also been used extensively by Brian May, Tony Iommi, MarcBolan, and Rory Gallagher. Tony Iommi's Rangemaster was modified to be full-range.
Hornby Skewes
Just like the Dallas Rangemaster, the Hornby Skewes treble booster was an amp-top unit. While early Hornby Skewes Treble Booster units used a germanium transistor, the later, better-known version features a silicon transistor. Rumours about a JFET version may source from a misread part number. It's prominently featured on Jethro Tull'sAqualung album. It was also used by Ritchie Blackmore during the 1960s until 1974, when it was replaced by a modified AIWAtape recorder. Hornby Skewes also made a bass booster and a treble and bass booster, the Hornby Selectatone T.B.2.
Vox
made a variety of boosters that were meant to be plugged directly into amps or guitars, including the model V806 Treble Booster. Roger McGuinn installed one into his Rickenbacker guitar in the 1960s.
Electro-Harmonix
Electro-Harmonix used to make treble boosters in two different enclosures. The Screaming Bird was a plug-in device, whereas the Screaming Tree was a foot-pedal. The circuits were supposedly identical. In 2009 the pedal was reissued, bearing the Screaming Bird name.
Colorsound Power Boost
The Colorsound Power Boost is a treble and bass booster that runs on 18 volts, using two nine-volt batteries. David Gilmour used this orange coloured unit, but is often misunderstood to have used an Orange brand Treble Booster. Other notable users include Gary Moore.