Turn down the volume settings on the Casio CTK-451 keyboard and the keyboard amplifier to about half of the desired sound level. Turn off the keyboard and amplifier. Plug one end of the instrument cable into the "Phones/OUTPUT" terminal jack on the rear panel of the keyboard. Plug the other end of the instrument cable into the "INPUT" jack on the reverb pedal.
Plug one end of the second instrument cable into the "OUPUT" jack on the reverb pedal. Plug the other end of the second instrument cable into the "IN" jack on the keyboard amplifier.
Turn on the keyboard, amplifier and reverb pedal. Play the keyboard and adjust the volume on the amplifier as desired.
Adjust the balance knob or dial on the reverb pedal to gain the desired effect. When the balance knob is on the center position, the direct sound and reverb effect sound will be equal, in a one-to-one ratio. Turn to the left to make the direct sound (the sound from the keyboard) more prominent. Turn to the right to make the reverb effect sound more prominent.
Turn the mode dial to the desired setting. Experiment with different sound combinations, such as delay lengths and reverb sounds, to come up with your own musical style.
Adjust the feedback dial, which may be marked "F. Back," on the reverb pedal to change the number of repetitions of the sound delay. Adjust the "D. Time," or delay time, dial to change the length of the delay time as desired. Sound delay is generally set in increments of microseconds.
Adjust the tonal color or timbre of the reverb sound by turning the tone dial.