Traditional steel-string guitars have always suffered from problems with maintaining optimal playing action. The stress of nearly 190 lbs of medium-gauge string tension deforms the top over time, causing the action to slowly rise and therefore requiring repeated action adjustments. This is particularly true of lightly braced handmade instruments, guitars braced for tone. Also, the effects of seasonal humidity changes make the action rise and fall throughout the year.
The traditional methods to adjust action have always been to first change the saddle height (or "shave the saddle"), and if that was not enough, to reset the neck angle. Both of these methods have serious drawbacks. Changing the saddle height is relatively easy to accomplish, but offers a limited range of adjustment. Moreover, changing the saddle height also affects the tone of the instrument since it changes the amount of leverage the strings have for driving the top. Resetting the neck angle on a traditional guitar is much more involved. Until recently, most steel-string guitars had necks attached by way of a glued dovetail joint. This method of neck attachment is quite permanent, and resetting the neck angle is a major repair job involving steaming the dovetail joint to loosen the glue, removing the neck, shaving away wood to change the angle, and gluing the neck back on. The advent of bolt-on necks made this operation much easier, but it's still work for a highly skilled luthier.
Doolin Guitars feature an Adjustable Neck Angle System. This system allows the guitar's action to be adjusted without changing the height of the saddle or removing the neck. The saddle stays at the optimum height for tone, while the neck angle sets the height of the strings over the frets. The available range of adjustment is wide enough to accommodate changes in string gauge, top deformation due to string tension over time, and seasonal humidity changes, for the life of the instrument. The adjustment is accomplished using a 5/32" Allen wrench.
Tone quality of the instrument is in no way compromised. Just as the bolt-on neck has proven to be the equal of the glued dovetail joint, the Doolin Adjustable Neck Angle System is the equal of either, providing a strong, stable attachment of the neck to the body. No sound energy is lost due to the close-tolerance fit of the joint and the strength of the hardware.
Adjusting the action couldn't be simpler: insert the supplied 5/32" Allen wrench, turn clockwise to lower the action, counter-clockwise to raise it. No need to loosen the strings.