Diagram of normal sinus rhythm as seen on ECG. In atrial fibrillation the P waves, which represent depolarization of the top of the heart, are absent.
The wah-wah pedal is based on a simple concept but its effect is far more dramatic. Using a powerful filter to sweep through a broad frequency spectrum, the wah pedal boosts and exaggerates specific tones. Creating sounds that range from thick, flubbery bass to scratchy, stinging treble.
A footswitch pedal such as the A/B pedal routes a guitar signal to an amplifier or enables a performer to switch between two guitars, or between two amplifiers. This footswitch controls an effect (distortion), but it is not an effects pedal as the case does not contain effects circuitry; it is just a switch.