My Latest Les Paul Greco. & an Intonation Question?

[Angry Possum]

The 1976 Greco L/P copy came in from Japan today, and packaged very nicely. Almost mint cond. This guitar has some wonderful Patina going on too. Anyhow when I played it, it had some real real bad intonation issues. So firstly I changed the strings, no real help. After looking at possible fixes I reversed the saddles, and bam it worked. Question is, is this ok. I know I could of adjusted the truss rod, but the neck was straight. So...

 

[Stillhouse]

Yep, no problem reversing a saddle to get that extra little bit of travel. Sweet looking guitar!

 

[Guitarmageddon]

The 1976 Greco L/P copy came in from Japan today, and packaged very nicely. Almost mint cond. This guitar has some wonderful Patina foing on too. Anyhow when I played it, it had some real real bad intonation issues. So firstly I changed the strings, no real help. After looking at possible fixes I reversed the saddles, and bam it worked. Question is, is this ok. I know I could of adjusted the truss rod, but the neck was straight. So...

View attachment 156011 View attachment 156013

Adjusting the truss rod is not how to fix intonation anyway, it's moving of the saddle positions.....

 

[Angry Possum]

The neck could of used a little truss tweaking, but I left it alone. I'm sure if I straightened it up a little I wouldn't have to reverse the saddles. It intonated very nicely with the saddle reversals. So I'm leaving it alone. It plays unreal. I'm so amazed.

 

[jamndad]

That's exactly what I would've done.

 

[John L Rose]

I had to reverse the bridge on my VM Jaguar to increase the length.
Before:

Note also that the tips of the saddle screws almost hit the string, which they would do if the bridge slipped and tilted back.
.
After:

Since then I've flipped it back again, but replaced some screws and springs with shorter ones.

Adjusting the truss rod is not how to fix intonation anyway, it's moving of the saddle positions.....

Well . . . unless the truss rod is way too loose.

 

[ghostwolf]

Well . . . unless the truss rod is way too loose.

Adjusting the truss rod has zero effect on the length of the strings, which is the only factor in setting intonation.

 

[LOSTVENTURE]

Done that more times than I can remember, mostly on Gibsons.

 

[John L Rose]

Oh yeah ... the neck should bow upwards ever so slightly (on the order of 2 mm or so?), and not be perfectly straight.
See http://legacy.gibson.com/Support/Tech-Tips/Basic-Guitar-Setup.aspx
The same goes for Fender/Squier instruments too.
If you change string gauges, you should check the truss rod adjustment again.

 

[Angry Possum]

Adjusting the truss rod has zero effect on the length of the strings, which is the only factor in setting intonation.

I disagree, I had a few guitars that didn't intonate correctly, and the truss rod tweak adjustment made up the difference. I'm serious

 

[John L Rose]

Adjusting the truss rod has zero effect on the length of the strings, which is the only factor in setting intonation.

Yes, but...
If the truss rod is too loose, the neck bows upward, and the action may be too high. Then the additional pressure required to fret a string will raise the frequency.
If you simply lower the bridge to correct the action then you will get fret buzz.

So, I set up truss rod first, bridge height second, and intonation third.
Maybe pickup heights last.

 

[ghostwolf]

Action & intonation are not interchangeable terms. Lowered strings don't pull sharp due to being raised too high, true. Similar to a properly cut nut- Cowboy chords play in tune.
But no matter how high or low your action is, the string will not change length without the saddle being moved forward or back.

 

[so1om]

I had to reverse the bridge on my VM Jaguar to increase the length.
Before:

Note also that the tips of the saddle screws almost hit the string, which they would do if the bridge slipped and tilted back.
.
After:

Since then I've flipped it back again, but replaced some screws and springs with shorter ones.


Well . . . unless the truss rod is way too loose.

The first pic where the intonation screws almost hit the strings? Raise the bridge and lower the pieces.

 

[Gerick Guitars]

Here is a very exaggerated example, but if the top line is the string and the bottom line is the fretboard, and then I straighten the fretboard to be parallel with the string , did the scale slightly grow? yes it did , therefore the intonation would slightly be off. Like I said this is a very exaggerated example
Edit; I mean it did not change the length of the scale, it change the length of the string from saddle to nut therefore it change the intonation slightly

Action & intonation are not interchangeable terms. Lowered strings don't pull sharp due to being raised too high, true. Similar to a properly cut nut- Cowboy chords play in tune.
But no matter how high or low your action is, the string will not change length without the saddle being moved forward or back.

 

[ElRey67]

The 1976 Greco L/P copy came in from Japan today, and packaged very nicely. Almost mint cond. This guitar has some wonderful Patina foing on too. Anyhow when I played it, it had some real real bad intonation issues. So firstly I changed the strings, no real help. After looking at possible fixes I reversed the saddles, and bam it worked. Question is, is this ok. I know I could of adjusted the truss rod, but the neck was straight. So...

View attachment 156011 View attachment 156013

I thought this would be the obvious question, but I haven't seen it posted:
Did you try adjusting the saddles prior to reversing them? I am not trying to sound like an ass, but that's why they are adjustable.

 

[Angry Possum]

I thought this would be the obvious question, but I haven't seen it posted:
Did you try adjusting the saddles prior to reversing them? I am not trying to sound like an ass, but that's why they are adjustable.

Yes. I ran out of room on saddles. Had to reverse them. That helped tremendously. I even took out the saddle springs out to give me more adjustment.

 

[John L Rose]

Action & intonation are not interchangeable terms. Lowered strings don't pull sharp due to being raised too high, true. Similar to a properly cut nut- Cowboy chords play in tune.
But no matter how high or low your action is, the string will not change length without the saddle being moved forward or back.

True.
Getting back to the original problem, the issue is not string length, but pitch change.
Three things affect that:

1. length (factory scale length, fretting, capo, intonation adjustment, pinch harmonics)
   
2. tension (tuners, whammy bar, pressing the string transversely, whether by fretting or bending)
3. string gauge, or mass per unit length (#2 - tuners - compensate for that.)

The first pic where the intonation screws almost hit the strings? Raise the bridge and lower the pieces.

I'll have to get back to you on that.

 

[Guitfiddlist]

Nice Greco!! I love those things!!

 

[ghostwolf]

And yet, the thread title includes the words "Intonation Question".

Been building and repairing guitars for better than 45 years now.
Not a player / hobbyist / tinkerer, but a trained professional. Forgive me for being particular about word choice, communication with customers is improved when both sides of the dynamic are on the same page.
So is my bottom line, financially.

 

[so1om]

True.
Getting back to the original problem, the issue is not string length, but pitch change.
Three things affect that:

1. length (factory scale length, fretting, capo, intonation adjustment, pinch harmonics)
   
2. tension (tuners, whammy bar, pressing the string transversely, whether by fretting or bending)
3. string gauge, or mass per unit length (#2 - tuners - compensate for that.)

I'll have to get back to you on that.

Essentially it’s math and geometry.