Tuning Variation Between 2 Guitars Overnight.

[Brucebubs]

2 Guitars on stands in my living room.
Next to each other.
Both tuned and played around the same time on the previous day.
Both exposed to the same overnight temperature and humidity conditions.

- The Epiphone has laminated back and sides, Grover Rotomatic tuners and is currently fitted with DR Sunbeam round core strings.

- The H&D is solid woods, Gotoh tuners and fitted with John Pearse Pure Nickels hex core strings.



This morning the H&D tuning is all slightly sharp - the Epiphone is still in perfect tune.
Even more surprising, The Epiphone has been in tune like this now for several weeks.

[Tico]

Perhaps this explains it:

On those guitars the strings have 3 sections.
1. The speaking length, nut to saddle.
2. The length at the head, from nut to tuning gear.
3. That short length from the saddle down to each string's ball.

After turning the tuning gear to the correct pitch the 3 sections are likely to be under different tension.
Why?
The two friction points, the nut and the saddle.
If the tension is left uneven it will equalize over time or during a hard strum.

That's why I strum the guitar hard after tuning, then recheck the tuning.
Then strum hard again.
Lather, rinse, repeat.

When all 6 strings are in tune after the hard strum the tension in the 3 sections has been equalized and the tuning will be more stable.

BTW, if you do this it doesn't matter whether you tune up to pitch or down to pitch.

I learned this principle from piano tuners.

[CASD57]

All solid
Solid top laminate back and side plus Epiphones/Fenders/Corts are overbuilt somewhat,

Thats the reason

[CASD57]

Oh yea..You gotta cat?

[MikeBmusic]

The humidity in the room changed enough that the solid wood guitar 'grew' (expanded) just a bit in length.

The Epiphone has been in tune like this now for several weeks.

Are you saying the guitar hasn't needed to be tuned in weeks - assuming you are actually playing it regularly? How are you judging this, by a tuner or ear?

[nedray]

Not very surprising at all. Solid woods expand and contract with relative humidity, which directly affects string length and intonation. My guitars are all solid woods and I live in a climate with fairly wide swings in humidity conditions at times. More humidity, guitars go sharp--sometimes as much as a quartertone in a day's time. Even the solid body electrics do it. Laminated wood is less susceptible to moisture in the air.

[Goodallboy]

I’ve never had, nor ever seen, any guitar that stayed in tune for several songs, much less several weeks.

[chippygreen]

Originally Posted by CASD57

Oh yea..You gotta cat?

This is definitely the reason. My cats actually open cases and fiddle with the tuning while I sleep just to mess with me.

[M Sarad]

I have similar problems with my solid body electrics.

[mischultz]

Metal composition and core geometry will also impact the strings’ response to atmospheric changes (temp, humidity, etc).

[vindibona1]

Two cannibals sitting at the dinner table eating a clown. One cannibal says to the other "Does this taste funny to you?".

Sorry Bruce... Your opening sounded like it had that sort of rhythm. Had to do it.

Someone else answered the question. But in general terms it has to do with the build of the guitar, the wood, possibly the metal composite of the strings and the way it all reacts to temperature and humidity variations. It's hard to say specifically.

You have round core strings on the Epi and hex core on the H&D. Could the grip of the winds on the JP strings be a- or the contributing factor while the round core allow a little more give?

Or could it be the truss rod? As I think about that, my basis for comparison is my '72 D35 with a solid unadjustable beam through the neck, while all my other guitars have adjustable truss rods. The Martin's relief hardly changes, even as we go through huge temp and humidity changes throughtout the year while my adjustables require relief tweaks 3 or 4 (or more) times per year. Perhaps as an experiment, if you have gap gauges you can measure and track relief between these two guitars? A change in relief will certainly translate to a change in tuning.

Or... Is it all or none of the above or something else entirely?

[CASD57]

Originally Posted by chippygreen

This is definitely the reason. My cats actually open cases and fiddle with the tuning while I sleep just to mess with me.

Yep, dang cats always looking for trouble

[JayBee1404]

Originally Posted by Goodallboy

I’ve never had, nor ever seen, any guitar that stayed in tune for several songs, much less several weeks.

Neither have I.

[Brucebubs]

Originally Posted by MikeBmusic

The humidity in the room changed enough that the solid wood guitar 'grew' (expanded) just a bit in length.


Are you saying the guitar hasn't needed to be tuned in weeks - assuming you are actually playing it regularly? How are you judging this, by a tuner or ear?

Clip on tuner.
I experienced very similar stability the 1st time I tried Martin Titanium strings - on a different guitar than these 2 mentioned.
At 10 months the Titaniums were starting to get harder to tune so I took them off.

I've had the DR Sunbeams on the Epiphone for about 4 weeks now - I play it every day - the strings are actually discoloring and look worn but still sound great - in the whole time they've been on the guitar they have only need minor tweaking 4 or 5 times in the first week.

It's 9.00am here - just checked them again this morning and today the H & D and Epiphone are both in perfect tune!

[AcousticDreams]

In general, I have found that when I put on a new set of Round cores, they stabilize quicker than my previous hexcore strings. Actually, I do not even stretch the roundcores.

However, some of the comments about laminates verses solid also make some good sense. The acoustic guitar's character, is always a bit of a mystery. And that is part of the fun of it.