DO-IN AWA-1 AUTO WAH

"What is an auto-wah? Auto-wah is a device that translates the envelope or "volume profile" of every musical passage automatically, into an easily-controlled, vowel-like sound, as you play. AWA-1 is a dynamic envelope follower commonly known as an Auto Wah. This effect gives you a "wah" sound that is dependent on how hard you pick the string. The harder you play the more intense the effect. It can be quite useful and dramatic when used tastefully.