PRS CE 24 - Note turns into harmonic

[Juan Luis Vidal]

After more than 25 years playing guitar I have never been this baffled with an instrument's issue: my brand new PRS CE 24, tuned in D standard, has a note that turns into a harmonic after a second. It's specially noticeable on the second string 12th fret but also on the first string 7th fret (same note).

It's been on the hands of a couple of seasoned luthiers who have checked frets, bridge, pickup height and whatnot...but the problem remains. It seems that the guitar itself is resonating in those particular frequencies.

Has anyone ever found a similar problem and, hopefully, a solution?

 

[JasonE]

If you tune the guitar to standard 440, does the problem move to a different fret? Meaning it is still the same note?

 

[ElrytNamrogo]

On my HBII, I've noticed that the 7th fret on the third string, after a second or two, will produce a harmonic of that note. I noticed that, for whatever reason, that note (D), once played fretted on the third string, will cause the open fourth string (open-D) to start to vibrate. Dampening that open string removes the harmonic note.

Strangely, it really doesn't do it with any other note. Playing the 10th fret on the first string (high-E), also a "D" note, will cause the fourth string to vibrate, just not as much as the 7th-fretted third string.

Very peculiar, for sure....my HBII is the only guitar that does this. I will say, all of my guitars have different ways of resonating and sustaining, some more so than others on specific notes. They all, simply put, have their own voice and way of vocalizing that voice.

 

[Simon Says]

I would start by checking if there is no loose hardware on a guitar; this may create wolf notes. Screw in all the bolts and nuts, including the block to the base of the bridge, and re-asses

 

[DISTORT6]

Put a piece of foam between the springs and cover of the trem.
Vibrating springs can do strange things especially since you said it’s the same note. The frequency might be doing it.
Worth a shot.

 

[Simon Says]

Put a piece of foam between the springs and cover of the trem.
Vibrating springs can do strange things especially since you said it’s the same note. The frequency might be doing it.
Worth a shot.

Totally this too.

 

[TFC]

Agreed on the trem thing. I put a single wrap of electrical tape on each spring to prevent what I always characterized as the guitar's "reverb".

 

[Juan Luis Vidal]

Thanks for all the tips and suggestions

- Tuned to standard E and the problem moved from second string 12th fret to second string 10th fret, which seems to suggest that there is no problem in the neck or frets but just with that very specific frequency.
- Just put tape on the bridge springs, used foam and screw everything I could see but the harmonic keeps being produced

Frankly, I am clueless what else to try

 

[MohnJayer]

It’s actually a kind of dead spot, a frequency which gets absorbed by the guitar to a greater extent than others.

 

[DISTORT6]

Thanks for all the tips and suggestions

- Tuned to standard E and the problem moved from second string 12th fret to second string 10th fret, which seems to suggest that there is no problem in the neck or frets but just with that very specific frequency.
- Just put tape on the bridge springs, used foam and screw everything I could see but the harmonic keeps being produced

Frankly, I am clueless what else to try

It’s possessed.
Exorcism.

 

[Simon Says]

It’s actually a kind of dead spot, a frequency which gets absorbed by the guitar to a greater extent than others.

Dead spots are muting the notes, not sustaining them into harmonics.

 

[AP515]

Dead spots are muting the notes, not sustaining them into harmonics.

I agree, but I still think what he is describing is a dead spot. If it is a true harmonic it's the opposite of dead spots, called wolf tones. But those are usually considered really cool and people don't want to get rid of them.

Dead spots happen more on 24 fretters than 22. Put a weight like a small C clamp on the headstock (put a cloth on first to keep from damaging the finish and see if it moves the spot. There really is nothing you can do about them, but you can minimize them by a number of tricks that have been mentioned on this site (search dead spots).

 

[Dirty_Boogie]

I agree, but I still think what he is describing is a dead spot. If it is a true harmonic it's the opposite of dead spots, called wolf tones. But those are usually considered really cool and people don't want to get rid of them.

Dead spots happen more on 24 fretters than 22. Put a weight like a small C clamp on the headstock (put a cloth on first to keep from damaging the finish and see if it moves the spot. There really is nothing you can do about them, but you can minimize them by a number of tricks that have been mentioned on this site (search dead spots).

I hate dead spots. All of my PRS electrics have one (22 and 24 fretters) - all in the 10-12 fret range on the B string. :-( I'd take a harmonic over a dead spot any day!

 

[Juan Luis Vidal]

Since I have never experienced them before I'm not really sure whether this a dead spot or not...looks to me more like a wolf note: it produces a loud squeal / harmonic and the note seems to keep sounding (not quickly dying away). I guess it could have some creative uses, but it usually annoys the hell out of me because it's located in some of the frets I visit the most when soloing.

Is it considered a manufacturing defect? Would it be worth to contact PTC?

 

[AP515]

Since I have never experienced them before I'm not really sure whether this a dead spot or not...looks to me more like a wolf note: it produces a loud squeal / harmonic and the note seems to keep sounding (not quickly dying away). I guess it could have some creative uses, but it usually annoys the hell out of me because it's located in some of the frets I visit the most when soloing.

Is it considered a manufacturing defect? Would it be worth to contact PTC?

Yeah, yours sounds more like a wolf tone. Dead spots fade away really quickly. It is not a defect. It happens because the resonant frequency of the neck happens to coincide with the location of the fret. when the two frequencies meet just right it's like touching the strings at the 12th fret, the dominant frequency is muted, and the harmonic comes out. When they oppose each other one frequency kills the other (like in a humbucker), and the note just dies. It happens on all makes of guitar, but the 24 freters (so PRS more than others) have a reputation of being worse for dead spots. Wolf tones are usually considered a benefit.

Here's a song from before the PRS era and it has about the longest wolf tone I know of, from about 3:20 to 3:38.

 

[JasonE]

@AP515 is on the right track and has provided you some good information. Try what he suggested in post 12. This is the reason I asked the question of whether the problem moved to a different fret with a different tuning. I didn't want to throw a ton of information at you in one post and took more of a troubleshooting approach by asking one question at a time.

The issue is due to the resonant frequency of the guitar overall. The only way to address that is to add or remove mass somewhere. That is why the approach of putting a small C clamp on the headstock is a good test. It should move the issue to a different spot or reduce it since there is more mass on the headstock with the clamp on it. If that works you could look into ways to add the mass the clamp is adding. There are a few ways to go about that.

 

[Juan Luis Vidal]

Surely playing live with a C Clamp on the headstock will move my looks into industrial metal or goofy territory, but I'll give it a try as soon as I can get hold of one.
Thanks everybody for all the useful info and tips.

PS: I always thought that sound in the BOC song was produced by good ol' feedback...the things you learn!

 

[MohnJayer]

Just hold the neck to a wall and anchor it there while plucking the string. No need to get a clamp for the test.

This is a nice clamp, the Fender Fat Finger: https://www.fender.com/en-US/access...tar-sustain-enhancer/0992180100.html?rdl=true

 

[show_a_little_faith]

Lots of good info/suggestions mentioned already. I'll add one other possibility - I had a slightly slack ground wire resonating in the pickup cavity, small piece of tape to secure it against the wood solved it

 

[AP515]

Surely playing live with a C Clamp on the headstock will move my looks into industrial metal or goofy territory, but I'll give it a try as soon as I can get hold of one.
Thanks everybody for all the useful info and tips.

PS: I always thought that sound in the BOC song was produced by good ol' feedback...the things you learn!

You are correct, the note is definitely being fed back into the amp, but if you listen at the beginning of the note the fundamental fades and the harmonic is what is driven into feedback.