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.
By function, there are some types of guitar pedals: Dirt pedals: all kind of overdrives, distortions and fuzzes that pushed the signal to break up, from light to extreme. Boosters and preamps (which add character) could be included in this type of pedals.