string buzz

[stewart]

Hi, I've just finished building my LP-1M, everything seems good except I have a lot of string buzz mostly on the lower strings (E A D).
I've let all the tension out of the truss rod but am still getting buzz. Any advice will be appreciated.
Stewart.

[Thigg88]

How is your action and string height?

[Andy40]

Hey Stuart.

I wouldn't be making huge changes with the truss rod, only small bits at a time.

The type of saddles on the LP models are uniform in height, which doesn't compensate for the thicker string gauges. (the EAD strings need more height to oscillate over the frets without buzzing). As Thigg said I'd probably try adjusting your string height first before attacking the truss rod.

Now that you've adjusted the truss rod dramatically, you may need to check that the neck is straight. You can do this by looking down the neck, if there is back bow or up bow you should be able to see it.

I would invest some money in two tools, a notched straight edge and a set of Stanley blades. the notched straight edge will show if there is back bow or up bow, then you can adjust with the truss rod.

The Stanley blades can be used as a fret rocker to indicate whether any of the frets are sticking up too high or lying low. If you get this far, post again and I'll let you know what to do.

[Simon Barden]

What Andy said. The truss rod should only be used to set the relief in the neck with the strings at normal tension. Though it does play a part in the overall action you get, it's the first thing to set up and after that you can normally forget about it. After that it's setting the bridge height, then the nut slot depth and then the intonation (saddle position).

It may be that some of the frets are higher then the others, but take things one step at a time. A notched edge has cut-outs for the frets, so that you can gauge the straightness of the fingerboard itself, without having to take into consideration any high (or low) frets. It's not 100% necessary to have one, but if you want to build or work on more guitars in the future, then its a great investment.

The neck should be slightly concave, just off flat. Hold the top and bottom E strings down in turn at the first and last frets, and you should just about be able to see a gap between the tops of the 7th and 8th frets and the string. The size of the gap can come down to personal preference, but around 0.5mm should be sufficient. Much above 1mm and there's a bigger gap than necessary, which will give you a higher overall action.

The next step is to adjust the bridge height. Always adjust it with the strings slackened, but always test it with the strings at normal pitch. You need to adjust it so that you lower it as much as you can and still have all the strings playing cleanly, without any buzz. You haven't done anything with the nut at this point, so the overall action will probably come down when you do, but you should be able to achieve a gap between string and 12th fret of around 1.0-1.5mm on the top E and 2.0-2.5mm on the bottom E.

If the gap has to be much larger than this, then there is probably an issue with one or two proud frets. You should be able to check by lowering the bridge height a bit until you get most of the frets sounding cleanly, but there are one or two places where the strings buzz against the next fret (or two) up.

If the strings are buzzing on the first one or two frets, then the nut slots for those strings are probably cut too low.

This is where the notched edge and the Stanley blade rockers come in, as you really need to confirm which frets are causing the problem.

But get this far and get back to us with measurements and/or photos if there are any of the issues listed above.

[dave.king1]

Wot Simon and Andy said.

If you set your bridge height to get around fret height / buzz issues you will almost certainly have intonation problems as you play up the neck.

The neck and frets may be good but you need to sort any issues here first otherwise you will be chasing your tail and finish up with a guitar that you are never going to be happy with.

[Simon Barden]

Going back to what Andy said - truss rod adjustments should be made slowly - never more than 1/4 turn at a time. Looking down the neck from the headstock, turn the truss rod to the right/clockwise to tighten the truss rod to reduce the amount of concave bow in the neck, and to the left/anticlockwise to loosen the truss rod and increase the amount of bow in the neck.

Too much tightening and you can put a convex curve into the neck, so that it's higher in the middle than at the ends. You don't want this, so be careful.

After any truss rod adjustment, make sure the strings are in tune and then check the result. If it looks good, then don't do anything else but wait for several hours - overnight if possible. The neck can take a while to settle down under a different truss rod tension, and may move a bit more over time. Once its steady and you have a good shallow curve, then proceed with the rest of the set-up.