Yet another fretbuzz question

TheOtherDennis

Having not played my guitars for weeks, I got them out for a quick strum last night.

Oddly, they were all out of tune. Now, I know that's not particularly odd, but they were all seriously sharp. Never had that before, but whatever.

Anyway, I thought, maybe they're all like that. So I went through my acoustics - the two I'd made and my two Avalons. All the same. Never mind, quick work through with the tuner and they're all fine.

Except...

I bought an Avalon L2-20 off a member of this forum a couple of years ago. It's a fabulous guitar. I played that a lot, up until the lockdown earlier this year.

Never had a problem with it, at all. Changed strings a few times, nothing but beauty.

But last night, once I'd tuned up (or down, to be precise, given it was sharp), it buzzed like a pissed off wasp. The B, G, A and low E strings all suffer pretty bad fret buzz for the first three or four frets, the B string worst of all.

Eh? How can that happen? It's kept on a stand, in the middle of the room, a good 7 feet from the nearest radiator, a similar distance from the nearest window or door. I've adjusted precisely nothing since I bought it, and as I said, right up until I'd not played anything a couple of months ago, it was completely fine.

Is it the strings? Is it possible they've stretched out of their natural best, and detuning them from being sharp has loosened them to a point that they now buzz when they shouldn't if they were new? If so, why hasn't that happened with the other guitars, because they're strung up with the same brand (Newtone)?

Or something else I'm not aware of? 

BahHumbug

Check the neck bow.  You'd get fretbuzz and hence low action if the neck had bowed backwards.  Don't ask how, but wood does move.

The first time I tried a Brook acoustic.....the shop assistant took down from the wall hanger where I think it had been for a while.  The neck was bowed backwards.  Cue frantic search for the correct truss rod tool.....

GTC

Guitar necks can move in mysterious ways left alone - and can usually easily be corrected with adjustment of the truss rod (although, in the case of Avalons, Lowdens and Larrivees, that isn't quite so easy unless you have the correct tool)

TheOtherDennis

But, and excuse my ignorance if I'm wrong, surely if a neck is going to bow under the pressure of the strings, it'll bow upwards, increasing the action, rather than backwards, to lower the strings and create buzz?

BahHumbug

A neck doesn’t bow only under the tension of the strings.  There is also the tension of the truss rod, and whatever shape the neck wood wants to adopt.  That shape will be influenced by temperature and humidity changes.  If the guitar has been hung up unplayed for a while then the change in the equilibrium of the three forces can result in random changes in the neck bow.  Could be backwards, could forwards.

FelineGuitars

No this time of year is very common for guitars that were fine all spring and summer to get backbow and fret buzz.

The change to colder weather seems to cause contraction in the rod & neck and you end up with needing the truss rod loosening a bit to get the back back to where it was .

If strings have been on a long while it may also be a chance to put fresh ones on, but it is mainly a truss rod adjustment that is needed.

We have already seen plenty of guitars needing this in the last couple of weeks

TheOtherDennis

Ah ok, thanks for that. I'll do both - change the strings and tweak the truss rod while I'm at it, if I can (given what @GTC said).

ICBM

It's the combination of colder temperatures causing the metal truss rod to shrink, and the higher humidity causing the wooden neck to expand, which results in the truss rod effectively being tightened significantly, causing a back-bow and fret buzz. This will pull all the strings sharp, and if the guitar is then tuned back down as well, even more buzz.

GTC

TheOtherDennis said:

Ah ok, thanks for that. I'll do both - change the strings and tweak the truss rod while I'm at it, if I can (given what @GTC said).

It's the position of the hex socket at the end of the fretboard under the brace just above the soundhole that makes it difficult to get at. You can get a shaped Larrivee tool (old style 5mm, new style 4mm) that makes it easier - but they are quite expensive. Otherwise it is a case of loosening the strings and reaching into the soundhole under the brace with a short Allen key.

GTC

I should add that the Avalon care booklet that came with my S7-OAK lefty stated that the truss adjustment was via a 5mm hex key. When carrying an adjustment I found it was actually 4mm.  

Mark1960

And the central heating thrown in for good measure

ToneControl

it's the humidity affecting the neck (and the top sometimes)

if you don't have the tool, tune down 2 semi tones and see if the problem goes away.
If it does, you need to buy the tool. Send Avalon your serial number and they will tell you the allen key size needed

ToneControl

GTC said:

I should add that the Avalon care booklet that came with my S7-OAK lefty stated that the truss adjustment was via a 5mm hex key. When carrying an adjustment I found it was actually 4mm.  

they used a different size for a while, I keep both sizes of tools

ToneControl

I bought 4mm and 5mm for £3.16 from ebay, free postage


I have an old Larrivee one anyway, those are a better shape, but cost a lot

GTC

You can find a cheaper (than Larrivee) shaped 4mm one here. Thais is the one I ended up using on my Avalon https://www.ebay.co.uk/itm/Acoustic-4mm-allen-key-wrench-truss-rod-adjustment-TO37/143644816874?hash=item2171e5f5ea:g:184AAOSwvYJe-fgI - £9.

The Larrivee 5mm one is available here https://www.ebay.co.uk/itm/Larrivee-truss-rod-wrench-S-N-4001-39999-3-16ths-or-5mm-UK-stock/192895838220?hash=item2ce97ce80c:g:NBwAAOSwL7VWrdil - £23 - I used this on my old Lowden

You can see that it is shaped to go around the brace at the top of the soundhole.

I can't see how the standard Martin-style ones would work comfortably.

Devil#20

Also why you should tune your strings down if you're going to store it for a while. In a worst case scenario it can pull the bridge off, or split the soundboard. 

sunshinewelly

I bought an allen key for my martin from amazon and someone must have had a bad day at the office as they sent me a bag of 10 indivdual ones . 

ToneControl

Devil#20 said:

Also why you should tune your strings down if you're going to store it for a while. In a worst case scenario it can pull the bridge off, or split the soundboard. 

not sure what this means

ICBM

Devil#20 said:

Also why you should tune your strings down if you're going to store it for a while. In a worst case scenario it can pull the bridge off, or split the soundboard. 

No, you shouldn’t - only if it’s going to be stored somewhere the temperature and humidity is likely to be unsuitable for storing a guitar, and then you should really think about whether that’s a good idea at all - and if you do, you should also fully slacken the truss rod. But it should only ever be a last resort if you have nowhere else - if it’s stored anywhere normal, it should be left tuned normally.

The only time you should normally detune a guitar for safety is for shipping, so the tension doesn’t cause or increase the damage if it’s dropped or cracked.

ToneControl

ICBM said:

Devil#20 said:

Also why you should tune your strings down if you're going to store it for a while. In a worst case scenario it can pull the bridge off, or split the soundboard. 

No, you shouldn’t - only if it’s going to be stored somewhere the temperature and humidity is likely to be unsuitable for storing a guitar, and then you should really think about whether that’s a good idea at all - and if you do, you should also fully slacken the truss rod. But it should only ever be a last resort if you have nowhere else - if it’s stored anywhere normal, it should be left tuned normally.

The only time you should normally detune a guitar for safety is for shipping, so the tension doesn’t cause or increase the damage if it’s dropped or cracked.

I've seen opposite advice on this from different sources. Is there any agreement out there on this one?

ICBM

ToneControl said:

I've seen opposite advice on this from different sources. Is there any agreement out there on this one?

Probably not - the ‘evidence’ usually quoted for not detuning is that most guitar manufacturers and dealers ship guitars at full tension. On the other hand, they can afford to replace them...

Dan Erlewine says to detune, which would be good enough for me even if I didn’t have personal experience as a repairer with shipping damage caused or worsened by full string tension - Gibson headstocks being the most common, but acoustic body damage too.