Ask the Expert: What Happens When Your Flattop Loses Its Flat Top?

Q: Four years ago I purchased a new guitar by a reputable maker. I love the way it sounds, especially now that it’s really breaking in. I briefly considered purchasing a vintage guitar, but quickly realized that great-sounding, problem-free vintage guitars are well out of my price range. Lately I’ve noticed that my top is no longer flat. In the right light I can see a faint bulge behind the bridge, as well as the outline of x-braces outside the soundhole. I’ve had a couple of minor action adjustments made and suspect these problems are related. Should I be concerned? —Otis Carlson, Shreveport, LA

A: Norman Blake, one of my guitar heroes and a connoisseur of fine vintage instruments, once remarked, “. . . no belly, no tone.” Since overhearing that statement many years ago, I’ve noticed that the correlation between top distortion and truly great vintage tone is . . . well, let’s just say it’s roughly on par with the reliability of Newton’s First Law.

To work efficiently, a guitar top must be built lightly enough to vibrate in complex ways. Wood, the traditional material of choice for guitar tops, distorts when subjected to pressure and heat (this is how we bend sides) and, given enough time, will distort in response to pressure alone. Add 175 pounds or so of string tension and it will eventually distort any top built lightly enough for conventional tastes.

Yes, guitars can be built to stay flat forever. On the extreme end of the durability scale is the Telecaster, which helped create new categories of music, although it never succeeded in eliminating demand for dreadnoughts. Composites, tentatively accepted in the classical guitar world, offer the promise of distortion-free steel string tops but have yet to catch on in a market that overwhelmingly favors traditional sound and appearance and retro, over progressive, trends.

I note that you love the sound of your relatively new guitar; that it is breaking in nicely; that its top shows signs of slight distortion; that your action needed minor adjustment. I am in agreement with your suspicion that these factors are related.

Newton’s apple is clearly headed in the direction of the ground.

I recommend that you enjoy your guitar and stop worrying about changes in its life cycle that are the result of similarities to the great-sounding vintage guitars you wish you could afford. At some point your top will stop stretching, and that point will roughly coincide with when you or your descendants stop wondering when your guitar will be fully “broken in.” In the meanwhile, you will probably need several more action adjustments. Be thankful for your lifetime warranty, because continued top distortion may cause your guitar to eventually need a neck reset, as is the case with an overwhelming majority of vintage guitars.

And please take my advice: Insist on a neck reset, as opposed to a top replacement.