Use the Allen Wrench to adjust the truss rod according to the warp of the neck.

For a forward or “U-shaped” bow, turn the truss rod counterclockwise. For a backward bow adjustment, adjust the truss rod clockwise.

A “U-shaped” bow is too tight; it has extra space toward the center of the neck, and bows outward and toward the strings. A backward bow is too loose; it arches inward and away from the strings.