Dana Bourgeois contributes the monthly Guitar Guru column to Acoustic Guitar Magazine. If you a question you’d like Dana to address in an upcoming article, please submit it to firstname.lastname@example.org.
Talking Torquing – Should I reset the neck on my vintage guitar?
Q: I recently purchased a 50-year-old Martin D-21. When it arrived, I instantly noticed that the action was really high. Unfortunately, there’s almost no saddle left, and the bridge may also have been lowered. The seller disclosed its condition, though remarked that he was almost always against neck resets because the guitar never sounds the same afterward. I used to assume that every old Martin would need a neck reset, but do admit that my ’64 D-35 never sounded as good after getting one. Any advice about what I ought to do next? Gordon Parris Boston, Massachusetts
A: The seller is right that a neck reset can change the tone of a vintage guitar. Neck angle not only regulates action but also affects mechanical forces that load and drive a top. Together, the bridge and saddle act as a lever, transferring string tension to the top in a torquing, twisting motion. A longer lever delivers greater torque load than a shorter one. By the same principle, a top is subjected to different torquing forces when its bridge/saddle assembly is pulled from different angles.
Guitars sound best when string load and top resistance are in relative balance. An underloaded top cannot drive enough air to achieve optimum volume, power, and presence; an overloaded top is unable to generate higher overtones and lacks sustain. One key to optimizing the mechanical efficiency of an individual top is knowing, with some precision, how it wants to be loaded.
It’s well known that ’30s-era Martins and Gibsons sometimes lose tone after neck resetting. These guitars are braced fairly lightly, and after decades of wear, tear, and adverse environmental exposure, many are at least somewhat structurally compromised. In some cases, particularly when bridge and saddle are restored to original height or higher, resetting the neck of an elderly guitar can push its top beyond the zone of just enough loading into the Qzone of too much. You may be surprised to learn that your mid-’60s D-35 is braced more delicately than D-18s, D-21s, and D-28s from the same period. Depending on the individual properties of its soundboard and the specifics of the reset, it’s possible that the loss of tone may be attributable to an overloaded top.
At face value, I wouldn’t be too worried about resetting a mid-‘60s D-21, especially if you can live with a chopped bridge and relatively low saddle. Compared to a ‘30s D-28 or a mid-‘60s D-35, that guitar is robustly braced, and the top of a guitar in “excellent” visual condition probably isn’t “tired out” or otherwise structurally degraded.
But it all comes down to the individual instrument and, specifically, how its top flexes. The question is: How much reset can your D-21 handle, and will it end up sounding the way you want? I recommend soliciting opinions from a variety of experienced repairmen and builders before deciding whether or not to reset; the more information, the better. And don’t be tempted to act until a solid consensus emerges from multiple credible sources.
If you do decide to commission a neck reset, expect to pay a price commensurate with quality of service. As the saying goes, “cheap is expensive”—you may only get one shot at doing this right. Also, understand that a neck reset can be as traumatic for the guitar as it is for the owner—a break-in period will therefore be required.
Lastly, be prepared for the probability of at least minor tonal change. Professional opinions should address the most likely possibilities. These can differ from one guitar to the next and between different reset scenarios on the same guitar. If your guitar already sounds fantastic and the reset is minimal, I wouldn’t be particularly concerned. If no amount of tonal change is allowable, then learn to put up with “really high” action, accept that your guitar may remain largely underplayed, or consider finding it a new home.