Why Does My Guitar Go Sharp?

[Three Eyed Willy]

I'm finding that my guitars are commonly a tiny bit sharp when I start. The "sharpness" is usually fairly consistent - as in, it is reasonably in tune with itself, just sharp. Every once in a while, but far less commonly, a guitar will be a bit flat. My house is pretty well climate controlled - consistent temperature between 70 and 75, and I keep a humidity meter in the room (always between about 42 and 65%). I keep all my guitars on a typical guitar stand. Just curious what makes a guitar go sharp...flat, I understand.

My first question is what you are using as a tuning reference? Are you using a Snark? A Peterson product? The level of quality varies from one brand to another.

Second, how do you judge your intonation? Comparing 12th fret harmonics to 12th fret note is usually pretty good, but you will be listening to sequential notes. It's much easier to calculate correct tuning if you can hear both tones simultaneously. Reading the intonation from a good tuner is probably as good a way as any.

 

[zekester]

How do you tune the guitar? Do you use an electronic tuner? There is the possibility that you're tuning it to a non-standard setting. It is actually quite easy to unset it, inadvertently, or accidentally, from standard A440 to something like A442 or A443. Many electronic tuners have the ability to deviate from A440. You might want to check into that.
If that's not it, you're ****ed.

 

[zekester]

My guitars go flat in fall/ winter then go sharp again in spring.

Is there some way to adjust that?

Yes. You need to stop the Earth's rotation during a season where you don't detect tuning issues.

 

[zekester]

A third factor I can think of is how forcefully you finger the strings. Press too hard, and it'll sound, and read, sharp.

 

[Tmcqtele65]

Thanks everyone for the activity on this thread - it has been a fun discussion for me.

I'm using a Korg chromatic tuner. It does have the ability to calibrate up or down to a different standard - and that button can sometimes get hit by accident - but that is not what is going on here.

As for intonation, the three guitars I have been playing are all fairly new to me. My acoustic is the newest, but it is the least affected. My Tele is a self-assembled partscaster, and I do need to make many adjustments (neck, bridge, truss rod, fret dressing, etc.), just not quite ready for that. The Gretsch hollow body is the most familiar of the three, and I had a lot more intonation "issues" initially until my muscle-memory got used to the finer subtleties of pressure required on this fret or that. The phenomenon I am describing here is an open-string tuning from one day to the next situation. Intonation may have some contribution, but all three guitars are fairly good that way.

Also - I'm asking this question more of a curiosity - this is not a problem. I'm an engineer with a physics proclivity and I have just been surprised that the "movement" of my tuning from one day to the next is most often going sharp, while I would expect either nothing, or the opposite.

 

[jefrs]

Possible causes -
1) It's not a Telecaster. A Telecaster will stay in tune if dropped down a flight of stairs.
2) it was not tuned in the shop (see 1 above)

TBH if I tuned a Tele a month ago, it will still be in tune. And so will be most of the other breeds.
When I put new strings on, which is not that often, I wrap them very neatly and tightly to the posts. I bring them up to roughly concert pitch and then thrash chords for about 10 minutes. This stretches the string and beds them in. Retune roughly to concert and put the guitar down at least overnight before retuning accurately to concert. Then it stays in tune.

 

[scottrandall]

It may be as simple as; If you tune your guitar sitting up straight, with the guitar sitting upright on your knees, then sit back with the guitar laying in your lap (as in a recliner), checking the tuning will reveal that gravity's effect on the neck alone, will make it go sharp - so similar, slight differences in how you tune/check for changes can have a similar result. Just sayin'!

 

[december]

Temperature change. Lower temp makes it sharp, higher temp makes it flat.
All winter, when I first picked it up, it was always sharp. It was 100° the other day and it was almost a full half step flat.
Even if your room is climate controlled, the guitar warms up while you play it, so to just not play it for a few hours is enough for it to cool down and go a little sharp.

 

[dcos]

My guitars infrequently go sharp between playing, but it does happen. I figure it has to be the neck being affected by temperature and humidity. Do your guitars sit in front of a window? Sunlight will be absorbed by the neck and heat it up.

 

[mcStringer]

It's temperature-induced.

When you play, your fingers on the strings warm them up a few degrees; that causes expansion of the metal. You tune the guitar and all is good. When the guitar is hung up or put away in the case, the strings cool off and contract a little bit, making them go sharp. It takes just a few degrees of temperature differential for this to occur.

Next time you pick up your guitar, run the palm of your hand up and down the strings about 10 times to create a little friction and warm the strings, and report back.

+1 I do this all the time. Works like a charm!

 

[SkinnyAss]

I'm finding that my guitars are commonly a tiny bit sharp when I start. The "sharpness" is usually fairly consistent - as in, it is reasonably in tune with itself, just sharp. Every once in a while, but far less commonly, a guitar will be a bit flat. My house is pretty well climate controlled - consistent temperature between 70 and 75, and I keep a humidity meter in the room (always between about 42 and 65%). I keep all my guitars on a typical guitar stand. Just curious what makes a guitar go sharp...flat, I understand.

Y'all folks whinin' 'bout keepin' yore 6 string electrics in tune, need to try playin' a 12 string acoustic for a while. While carryin' on with some other pickers one evenin', I puzzled over my need to down-tune after nearly each song. I asked Bob 'bout the often exasperatin' challenge of keepin' all 12 strings in tune. Bob said, "We 12 string players spend half our time tuning, and the other half playing out of tune."

 

[Tom Grattan]

Lot of talk about the environment, heat, humidity, cold etc. Well, I have to say that every time I pick up a stringed instrument to play I make sure it's in tune. Occasionally it's in tune but usually it's slightly out, at least of a few strings. So I would never pickup a guitar without checking the tuning. It's natural at this point, kind of like putting on your seat belt in the car. When you play the instrument it will go out of tune. Tuning is one key to helping your ear hear pitch.

 

[jdiego]

I had the same problem with a steel strings acoustic I've hanging in the wall. The rest of my guitars are always in tune, but I keep them inside cases. The culprit was seasonal cold weather and nut slots that needed to be polished.

I would recommend to polish those nut slots with 1.000 grit sandpaper.

There's a very easy method for knowing if the nut slots are catching the strings:

- Using a guitar tuner, check the tuning of a specific string
- Stretch the string pulling it up with the picking hand and check the tuning again
- Stretch the string pulling it up behind the nut, in the headstock area, and check the tuning again

If the strings are correctly installed without slack around the tuning machine posts, and the nut slots are not catching the strings, stretching the strings from both sides of the nut shouldn't affect the tuning.

For me, polishing the slots with 1000 grit did the job.

Correctly installing the strings is also very important. It took me 20 years to learn how to do it right, like this:

 

[PHutch]

I'm finding that my guitars are commonly a tiny bit sharp when I start. The "sharpness" is usually fairly consistent - as in, it is reasonably in tune with itself, just sharp. Every once in a while, but far less commonly, a guitar will be a bit flat. My house is pretty well climate controlled - consistent temperature between 70 and 75, and I keep a humidity meter in the room (always between about 42 and 65%). I keep all my guitars on a typical guitar stand. Just curious what makes a guitar go sharp...flat, I understand.

A couple of the guys have it right, the strings have cooled off. Vibrating the string makes it heat up, fretting also induces energy, and there possibly is little heat transfer from your hand. Someone with an accurate No Touch thermometer should check it out.

 

[klasaine]

Thanks everyone for the activity on this thread - it has been a fun discussion for me.
Also - I'm asking this question more of a curiosity - this is not a problem. I'm an engineer with a physics proclivity and I have just been surprised that the "movement" of my tuning from one day to the next is most often going sharp, while I would expect either nothing, or the opposite.

Since you're an engineer, you will LOVE this book ... https://www.google.com/books/editio...J3NxAwAAQBAJ?hl=en&gbpv=1&printsec=frontcover
It has some math in it that is beyond me so you'll probably get more out of it than I did.

 

[Festofish]

Tune it flat.

 

[xtrajerry]

Definitely noticed this much more when I lived in an apartment.. in my house where I control temperature and humidity no so much.

 

[nortally]

It's temperature-induced.

My BS joke answer is that metal shrinks faster than wood, thus over time the tension would increase
But I totally agree with you. Note that the problem can be solved by storing your guitars in the back of an SUV in the sun on a hot day.

 

[NoTeleBob]

Thanks everyone for the activity on this thread - it has been a fun discussion for me.

I'm using a Korg chromatic tuner. It does have the ability to calibrate up or down to a different standard - and that button can sometimes get hit by accident - but that is not what is going on here.

As for intonation, the three guitars I have been playing are all fairly new to me. My acoustic is the newest, but it is the least affected. My Tele is a self-assembled partscaster, and I do need to make many adjustments (neck, bridge, truss rod, fret dressing, etc.), just not quite ready for that. The Gretsch hollow body is the most familiar of the three, and I had a lot more intonation "issues" initially until my muscle-memory got used to the finer subtleties of pressure required on this fret or that. The phenomenon I am describing here is an open-string tuning from one day to the next situation. Intonation may have some contribution, but all three guitars are fairly good that way.

Also - I'm asking this question more of a curiosity - this is not a problem. I'm an engineer with a physics proclivity and I have just been surprised that the "movement" of my tuning from one day to the next is most often going sharp, while I would expect either nothing, or the opposite.

Pick up your guitar. Hold the low E string at the 1st fret with the left hand and the 17th fret with the right hand thumb. Take a look at the relief between the bottom of the string and the 8th fret. Now stretch the right hand so the pinky finger can push it up and down a little while you watch the gap. Get a visual feel for the clearance aka light-space.

You may find it easier to use a capo on the first fret. You might also want to use feeler gauges or old bits of strings to measure if your eye isn't used to this sort of measurement.

The next day before you play, do it again. See it the neck is moving. We're talking tiny amounts here... if you measure .010 one day and .013 the next, that's enough to be way out of tune.

 

[Peegoo]

Note that the problem can be solved by storing your guitars in the back of an SUV in the sun on a hot day.

Yikes! I learned that lesson last week when I left my Les Paul in my car all day.

It melted a little bit, but it still works okay.