This version of the EA Tremolo is based on the original circuit with some mods added. This effect pedal is a wonderful sounding tremolo, and while the circuit is relatively simple the EA Tremolo sounds very warm and pleasant to the ear. If you are looking for a more radical sounding tremolo, you should check the Pulsar Tremolo Kit.
As it doesn’t include any kind of optocoupler, the EA Tremolo is quite easy to build. A very rounded modulation wave is generated by the LFO, and that’s why the EA Tremolo sounds so natural.
The EA Tremolo effect pedal has a Speed potentiometer, which sets the frequency of the LFO, and a Depth knob to adjust the intensity of the tremolo.
But, besides being used as a tremolo, the EA Tremolo can also be used as a booster: the Volume knob sets the output volume of the pedal and allows you to get a bit more volume without needing a booster pedal.
Download here the manual for the EA Tremolo Kit: