Tune – Relief – Action – Intonation – Nut (?)

The traditional T.R.A.I.N. sequence—Tune, Relief, Action, Intonation, Nut—sounds logical on paper, but it breaks down in real-world execution. The problem isn’t the individual steps; it’s the order. By placing the nut last, you’re making a critical height adjustment after you’ve already finalized two other height-dependent systems: action and intonation. That guarantees rework.

According to Pythagoras (the father of geometry)

Here’s the mechanical reality: the string is a straight line between two endpoints—the nut and the saddle. Change either endpoint, and you change the geometry of the entire string path. The 12th fret (where action is typically measured) sits at the midpoint, so any height change at either end affects that midpoint by roughly half the amount. It doesn’t matter whether you call one end the saddle and the other the nut—physics doesn’t care. Raise or lower either one, and the action at the 12th fret moves accordingly.

T.R.A.I.N. Is a Train Wreck for Your Business!

So when you follow T.R.A.I.N. and leave the nut for last, you’re introducing a variable that directly alters the action you just set at the saddles. Lowering nut slots will reduce overall string height, especially in the lower positions, but it also pulls the entire string line downward—changing the 12th fret action and, in turn, affecting intonation. Now your previously “finished” setup isn’t finished anymore.

This is why high-level setup work requires a different order of operations—one that respects dependency. The nut is not a final touch; it’s a foundational height reference. If you don’t establish it early, and independent of action, every downstream adjustment becomes unstable. A proper sequence eliminates rework by locking in the fixed geometry first, then refining from there.

Old Wives Tales

Due to the lack of standardized guitar setup processes, for decades techs have been trained by other experienced, but also untrained techs, who were taught from others. The cycle continues with misinformation being handed down from well-meaning instructors.

My uncle tells the story about my aunt cutting off one end of the holiday ham each year.  When asked “Why?”, her response was “That’s the way my mother always did it.”.  Curious, my uncle asked his mother-in-law, who gave the same response.  Fortunately, my aunt’s grand mother was still alive, so he asked her.  Her response? “Our oven was too small for the ham, so I’d always have to trim the end off.”

The MasterPro Guitar Setup™ system may not be too different from what you’re currently doing. Most experienced techs will find they already follow many of these principles—this simply formalizes, sequences and verifies them.