Based on Klon® Centaur
The Klon Centaur is a guitar overdrive pedal developed by Bill Finnegan between 1990 and 1994. The pedals were made manually by Finnegan. The Centaur is characterized as a “transparent” overdrive, meaning it adds gain to the signal without significantly altering the tone of the guitar.
About 8,000 units were built between 1994 and 2000. Guitarists praised the clear, uncolored tone of the boosted signal. The circuit had unique characteristics, most noticeably the use of an IC MAX1044 voltage converter. The voltage converter drives 18 volts to the operational amplifier which is the core of the circuit; at this voltage the response of the amplifier is different than at 9 volt, since its slew rate depends on the voltage supply. Higher the voltage supply, higher the order of harmonics the operational amplifier will generate, and more metallic the sound. Depending on the position of the knobs, the overdrive effect could be created in the amplifier instead by the circuit itself. The circuit had two germanium diodes to perform clipping. The “gain” knob is a double potentiometer (a “dual-ganged gain pot”), which controls bass and middle frequencies. Other knobs are treble and volume.
Nowadays, original units cost upwards of $1500 and are considered collector’s items. The Klon centaur is often used as a standard to compare new distortion pedal designs.
In 2014, Finnegan sold the same effect under the name “KTR”. The KTR features the same circuit, but uses surface-mount technology to make the pedal smaller than the original, and to make it compatible with mass production. The diodes, however, are still the same as the original pedal. Screen printed on the front of the KTR are the words “kindly remember that the ridiculous hype that offends so many is not of my making”, in response to the cult following garnered by the original Centaur.
Among the guitarists who use the Klon Centaur are Jeff Beck, Robert Friedrich and Jason Lamont, as well as Warren Haynes, Britt Daniel (Spoon), Nick Valensi (The Strokes; CRX) and John Mayer. Nels Cline of Wilco once said, describing his Klon “…It’s an amp in a box. No more worries in the world of ‘amp du jour’ about overdrive tone. It will be OK. The Centaur will take care of it…” Thaddeus Hogarth, a guitar professor at Berklee College of Music, describes the tone of the Klon as “dynamic…[it] works in combination with your guitar sound…