Minor 12 string issue - take to tech or DIY?
 

I have a brand new (to me) Taylor LKSM-12 that I absolutely love. It plays like absolute butter with the light strings it came with, and to my surprise the light strings still sound pretty good tuned down. However, I am still tempted to put heavy stings on it (tuned down) as the design intended.

Now to the problems: Guitar plays beautifully with crazy low action everywhere except it buzzes and splats out on the 3rd fret of the high E. Obviously this is an important note and very inconvenient. Do you experts think that putting heavier strings (.012-.054) will put just enough more tension on the neck to lift the strings by a hair and potentially solve this buzzing issue? Also, do you think a full tech setup is necessary to redo the nuts slots to accommodate heavier strings?

I'm only hesitant to take it to a pro bc I really don't want the action to change at all besides the string gauge and the buzzing on one fret. Feels like I'm basically just asking for a string change.

it would seem, based on your assessment, you have a high fret there.

if you have a fret rocker, (found on Amazon for cheap ones) you would be able to detect that for sure.

There are a few ways to fix this, but you'd need at minimum a BUZZ OFF kit to knock that fret down and still ensure the fret's crown is not compromised.

easy fix for a good repair tech.

and.. I would not put heavier strings on that myself..

If the fret is high, I would let a tech look at it. If it's a relief issue, just loosen the truss rod a 1/8 turn or so and see if it is gone. The heavier strings tuned down will be close in tension to the light sets tuned to pitch. If you are using light strings tuned down then you probably need to add a little relief to the neck (loosen) because the relief was likely set when the guitar was at concert pitch.

Agree with Steve…
 

If it’s just one string at one fret the most likely cause is a slightly high section of fret under the string.

I’d check with a fret rocker (very short straight edge). If the fret is high then the first step would be to check it’s seated properly, sometimes the fret just needs reseating across its length, or at a specific point or points.

Knocking down and re-crowing a fret, or small section is a quick job but requires some skill and specialist tools.

My suggestion would be to take it to a good tech/luthier armed with the above information and discuss options. Any self-respecting luthier should be able to resolve this issue for you without affecting overall playability and feel.

Depending on whether the nut is original, the string slots will have been cut at the factory to accommodate the heavier gauge strings that came with this model. Once you’ve resolved the buzzing issue you could try swapping the strings out and see how the heavier gauges work. It will be immediately apparent whether the nut slots are suitable and once strung up whether any truss rod adjustment is needed.