The Seymour Duncan Vise Grip is a studio-grade compressor designed for guitarists who want to take control of the dynamics of their sound, from a subtle smoothing-out of peaks and valleys to the most squished and pinched extremes and everywhere in between. The Blend knob lets you add as much or as little of the original signal as you like to the compressed sound, while the Mid/Full/High lets you choose the character of the blended signal. The Sustain knob determines how long your notes will ring out and the Attack control regulates how quickly the compressor reacts to your initial pick attack. Higher settings give you a late attack that lets your picking dynamics come through before the compression kicks in. And the Volume control does more than just let you match the output with your bypassed sound: you can also use it as a boost while taking advantage of the Blend and Mid/Full/High controls.