Weird tuning problem

[sterlingsilver]

Hi everyone,

I have a PRS SE Custom 22 with a weird tuning problem.

Basically, all the notes above the 12th fret are sharp. And all the notes below the 12th fret are flat. The problem gets increasingly bad the farther you get away from the 12th fret.The guitar is basically intonated as far as my own abilities go (open-string to 12th fret and harmonic), so this issue seems quite baffling.

 

I've searched online for awhile and can't find anything on this. Here are my best guesses and the reasons why I doubt them:

 

Some might say neck/body/mechanical trouble, but the guitar has been basically taken care of and is a PRS. Plus the strings are consistently out of tune in an increasing way up and down the fretboard. On each string, the tuning is playable from say the 7th to 15th frets, but is clearly out of whack by the 3rd or 19th each way.

 

My best guess is that recently I went up from .009s to .010 guage strings. Still, I can't believe that every string would be equally affected by a not-quite-matching nut. I really don't know enough about neck/body/vibrato mechanics to know how this would affect things. I would try to adjust to the neck or bridge-heigth but I'm not even sure which direction I should go with it.

 

I can probably look up proper string height/distance, etc. across the fretboard, but so far I haven't come across this particular case in my research so I just wondered if any of you have encountered this before or can guess better than I can.

 

I have changed the strings and the problem persists. I believe the guitar was fine before I changed string sizes, but I can't say for sure if it was an immediate/cause-effect thing.

 

Thanks for any ideas.

[Caevan O’Shite]

Hmn; how long have you had this guitar? Did you buy it brand-new? Is it still under a valid warranty? If so- let PRS and/or the dealer you purchased the guitar from help you with this. DO NOT VOID YOUR WARRANTY.

 

 

If NOT still under warranty:

 

 

Have you adjusted the truss-rod since changing up to the 10s from the 9s? (Chances are, it would have needed to be tightened just a little, for a little less relief bow, as the heavier strings will have pulled harder on the neck than the previous lighter gauge set.)

 

 

Try using a very accurate tuner, such as a true strobe-tuner, a Peterson StroboStomp (use the Strobo's the EQU equal-temperament setting to initially tune and set intonation, and then try tuning-up with its GTR preset), a Sonic Research Turbo Tuner, etc. to tune and set the intonation. Or, take the guitar to a qualified, experienced repairer/luthier who has and uses such a tuner, and explain the problem to them.

 

 

Be sure that the pickups aren't too close to the strings, particularly the neck-pickup; if too close, pickup-magnets can sometimes pull strings out of tune, especially the wound-strings. This usually isn't a problem with humbuckers, more often occurring with Fender Strat-style single-coils, but I suppose it's possible.

 

 

Be sure to let us know how you make out with this; keep us posted!

[The Geoff]

Mmmm. That's an interesting one.

 

The only scientific reason I could think of for that one is that if a a long-scale neck was mounted on a body intended for a shorter scale. This would give the 'sharp above octave & flat below' effect, but I've never heard of it before.

 

Do what Caevan suggests. And hope.

 

G.

[Caevan O’Shite]

Come to think of it, you do have that trem-bridge on there...

 

I think that a total set-up using the exact same brand, type, and gauges of strings that you intend to stick with (and DO stick with one exact same brand, type, and gauge!), tuned exactly the way you intend to generally use this guitar (I assume it's Standard/A=440hz), will run off your intonation gremlins, at least for the most part...

 

 

Besides the truss-rod usually needing a little tightening-up when switching from lighter to heavier strings, the screws that hold the spring-claw in the back of the body will usually need at least a little tightening, as well- just enough to compensate for the increased tension of the strings pulling forward on the trem.

 

If this type of Fender Strat-based fulcrum-trem is pulled a little more forward by the heavier strings, all six saddles will also be raised UP in height for a slightly higher action, as well. This could exacerbate intonation issues in a way like you describe...

 

If the guitar played and intonated satisfactorily when you had the 9's on there, now that you have switched to 10's, don't adjust the action by adjusting the individual saddles- instead, adjust the truss-rod in the neck accordingly for proper relief, and then block the trem in place with the overall bridge-height where you want it, tune-up, remove the blocks, and adjust the spring-claw until the bridge is balanced at a zero-point that is the same as where you had it blocked-in at. THEN adjust the intonation, preferably with the most accurate tuner (using equal-temperament) that you can get your hands on.

 

 

I have found that, when under the effective 'microscope' of a strobe-tuner or virtual/digital strobe type like the Peterson StroboStomp, MANY guitars show what seems to be dodgy, questionable intonation over much of the fretboard, including many pricey big name-brand axes. This is due in part to the fact that there really is no such thing as "perfect" intonation; it's all a game of compromise and compensation with MANY variables, and the ear won't and can't always hear the difference- which is often a blessing in disguise.

 

 

Again, keep us posted on how things go for you here, and best of luck!

[Scott Fraser]

The only scientific reason I could think of for that one is that if a a long-scale neck was mounted on a body intended for a shorter scale. This would give the 'sharp above octave & flat below' effect, but I've never heard of it before.

 

In this case, though, the PRS SE Custom is a set neck, so, as a client's daughter often says, "Science can't explain it!"

 

 

[The Geoff]

The only scientific reason I could think of for that one is that if a a long-scale neck was mounted on a body intended for a shorter scale. This would give the 'sharp above octave & flat below' effect, but I've never heard of it before.

 

In this case, though, the PRS SE Custom is a set neck, so, as a client's daughter often says, "Science can't explain it!"

 

 

Fair 'Nuff!!

 

G.

[sterlingsilver]

Thanks a ton! I'll look into that. It's probably the first thing I've come across that made some sense.

I may be looking into getting a new tuner anyway soon, but I don't think that's to blame here at all because I can hear the difference myself (and I don't have great ears!). So thanks again.

[sterlingsilver]

So anyway, here's an update with good news...

I did what you said and tightened the claw and voila! Sounds perfect.

Now, I'm not so precise/professional just yet: no strobe tuner, etc. but it actually sounds fine, and that's all that matters right?

To be more informative, I got the brilliant idea to look up the specs on the PRS website. And it said that the bridge should float parallel to the body and about 1/16" above it. It took some trial and error (and I had to go buy a ruler, Hah!), but it worked out fine. So thanks again!

[Caevan O’Shite]

You're not kidding, "trial and error"- been there, tediously done that!

 

Glad that things worked out for you; don't be a stranger...

[Larryz]

Glad you got her working...

[Scott Fraser]

So anyway, here's an update with good news...

I did what you said and tightened the claw and voila! Sounds perfect.

Now, I'm not so precise/professional just yet: no strobe tuner, etc. but it actually sounds fine, and that's all that matters right?

To be more informative, I got the brilliant idea to look up the specs on the PRS website. And it said that the bridge should float parallel to the body and about 1/16" above it. It took some trial and error (and I had to go buy a ruler, Hah!), but it worked out fine. So thanks again!

 

Glad that worked. On a whim, because I just ran across the spring in a drawer, I decided to try adding the 5th spring to the whammy bridge on my PRS SE to see if a tighter feel would make it more controllable, less wild. It threw things so far out of wack I didn't even bother to retune it. I couldn't pull up more than about a quarter tone, instead of the usual whole tone. So, right back to 4 springs, as it had been delivered. I'd never experienced before the dramatic effect that tremolo tension can have on things. It's pretty important to get it right.