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.
The effect is called flange because before the advent of flanger pedals, sound engineers and musicians would press the inside of the thumb (the flange) onto the tape reel to slow it down and speed it up to achieve the desired effect.