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 tone knobs on your guitar act as a built-in equalizer on your guitar, which control high and low frequencies produced by your guitar's pick-ups. Some guitars have only one tone knob next to the volume knob. Other guitars have as many as three or four tone knobs.