An Auto Wah pedal (or Envelope Filter) automatically creates a "wah" sweep by reacting to the input signal's volume, or "envelope," making a manual foot treadle unnecessary. Top pedals like the Boss ...

The wah-wah pedal makes a guitar sound as though it's singing "wah, wah, wah." The effect was a staple of 1960s psychedelic rock: Jimi Hendrix bent reality with it in classics like "Voodoo Child ...

The wah pedal has been responsible for some truly iconic moments in electric guitar; that 'talking' sound you've heard from players including Jimi Hendrix and Richie Sambora on classic songs. Listen ...