Optisk Tremolo-pedal baserad på de klassiska Tremolo-effekterna från det sena 60-talet. The history of the Tremolo effect dates back to 1941 and the Tremolo is oftenly referred to as the first real guitar effect ever. The Tremolo circuits of the 50's was relatively simple, using as little as a dozen components and one half of a tube of the preamp circuit. The effect was achieved through "bias wiggle", in which the bias of a tube, in the preamp or output stage, was turned off and on, or partly off and on.By the mid 60's, Tremolo was produced using an optocoupler, a light-dependent resistor whose pulsating signal affects the preamp circuit, generating the signature sound heard on many of the most famous albums in rock/pop music history. This effect is still widely used in many music styles and referred to as an Optical Tremolo. The Black Sheep Trelicopter Tremolo offers the iconic Optical Tremolo sound of yesteryears, with controls for Depth, Speed and Bias, giving you a wide range of the sweetest Tremolo imaginable. Trelicopter Tremolo is a compact, true bypass, sturdy built pedal that delivers the classic, sought after Optical Tremolo at an affordable price.