How it Works Welcome to the world of Direct String Synthesisœ. The principle is simple: a focused feedback loop directed at a single string. This produces a powerful, infinite sustain, rich in harmonics for incredible guitar sounds. It´s like amplifier feedback with greater control and predictability, at any volume, even through headphones. This handheld synthesizer provides an amazing variety of textures and tonal slurs — virtually an instrument in itself! Direct String Synthesis Ebow is a synthesizer in the palm of your hand. Complete control over attack, decay, and dynamics, as well as a whole new range of tones and textures, makes the EBow one of the most expressive tools ever designed for guitar. Whether sweeping smoothly from voice to voice or jumping from sound to sound, this device is responsive and personal enough to reflect your playing style.