A simple spring reverb guitar effects circuit

This is a simple spring reverb guitar effects circuit that can be built at a low cost, requires only a minimum number of electronic parts and of course the circuit itself requires a minimum of space. The circuit is also easy to build and requires a 9V DC power supply to operate.

The operational amplifier (op-amp) is a quad channel type using the RC4136N IC (datasheet here), the pinout for the 4136 is shown above but can be substituted with other types. The bypass caps C1 and C2 can be 10 to 100 uf. If you experience distortion in your reverb you may want to reduce the resistors marked with an *, lower them to get the maximum signal without distortion. Many spring reverb units can be used with this circuit, the original article suggests using an accutronics model. Many reverb units also use RCA style jacks as inputs and outputs, be prepared for that. De-activating the switch will turn off the reverb effect without any clicks or pops. All resistors are 1/4 or 1/2 watt with a 5% tolerance, all capacitors are rated for 10 volts or more.