The Ibanez Tube Screamer (TS808/TS9) is a guitar overdrive pedal, made by Ibanez. The pedal has a characteristic mid-boosted tone popular with blues, rock and metal players. The Tube Screamer has been used by many guitarists to create their signature sound, and is one of the most successful, widely copied, and custom-modified ("modded") overdrive pedals in the history of the electric guitar. Description The Tube Screamer has a drive knob, a tone knob, and a level knob. The drive knob adjusts gain (which can affect the amount of distortion), the tone knob adjusts treble and the level knob adjusts the output volume of the pedal. The Tube Screamer name refers to the pedal's ability to drive the preamp section of a tube amplifier, resulting in more gain from the amp itself. The pedal also provides a slight boost to mid-range frequencies, helping to reduce muddiness by cutting bass frequencies when used in this way. Some guitarists prefer this sort of equalization, as it helps to keep their sound from getting lost in the overall audio mix of the band. This, along with its versatility as a simple distortion, has made the pedal very popular for a wide variety of styles and situations. Variations The pedal was produced with many variants: The Tube Screamer pedal was preceded by the orange "Overdrive" (OD) and green "Overdrive-II" (OD-II). These came in narrower boxes without battery covers. There was also a reddish "Overdrive-II" which had a housing very similar to the TS-808/TS808. The green OD-II had a circuit similar to the TS808; however, the OD and OD-II had a more distorted circuit. TS-808/TS808: The first Tube Screamer, the TS808, was released in the late 1970s. It was equipped with the Japanese JRC-4558 chip. Some units however had the Malaysian-manufactured Texas Instruments RC4558P chip. TS9: From 1981 to 1985, Ibanez produced the "9-series" of overdrive pedals. The TS9 Tube Screamer is almost the same internally as the TS808 but the TS9 had a different output, which caused the pedal to sound brighter and less smooth. In later years, TS9s were assembled with a wide variety of op-amps, instead of the sought-after JRC-4558. Once Ibanez discontinued the 9 series pedals, they introduced the "Master" or "L" series. These were only made in 1985, and did not have the Tube Screamer in the line-up. A rare and valuable version of the Tube Screamer was the ST9 Super