The FX Files: Klon Centaur
The original ‘holy grail’ pedal, a perfect condition Klon Centaur could set you back thousands of pounds
The gain control serves a dual purpose on the Klon. As well as increasing the output of the op-amp stage, and thus modifying the clipping behaviour of the pedal, it also has effects on the midrange and bass filtering. As two germanium diodes perform a hard-clip after this stage, feed-forward networks and a summing amplifier follow in the circuit to make sure that the clean signal is preserved, radically changing the character of the pedal and giving it its ‘transparent’ feel.
The treble control is an active high-pass filter, which boosts or cuts frequencies above 400Hz. The counterpart to this is that the clean blend path of the dual-gang gain pot forms a low-pass filter at around 500Hz, substantially pronouncing the mid-hump of the Centaur.
A simple shunt-to-ground, the output control allows you to attenuate the output signal from the pedal. At more extreme settings, the Klon can deliver a lot of output from its amplification stages and needs taming.