An adjustable neck system for ease of action adjustment within a wide range of possible string heights and vibrating string lengths while not impeding on the vibrating area of the soundboard and adding minimal mass to the headblock assembly and allowing for significant rigidity to allow for greatly improved tuning stability is described. The system includes a neck joint utilizing a neck that pivots into a slightly mortised headblock with a floating, cantilevered fingerboard that does not contact the surface of the soundboard. The neck heel features extensive reinforcement in conjunction with headblock reinforcement to allow for increased torque on between the captive bolts and pivot points for greater rigidity and stability without the need for locking screws. By laminating the headblock and cantilevering the fingerboard, mass and soundboard contact area is not significantly greater than with traditional assemblies for minimal effect on weight balance and tone.