Intonation issue ~ string gauge related, or what else ¿?¿

ChrisMusic

Scale length is a nominal 25.25" according to our dodgy old tape measure @earwighoney .

There are some more accurate measurements for nut >12th > bridge, and also nut > 5th > 12th, for harmonic nodes, in my last post above this one, if that helps your inner Sherlock Holmes.  Any and all help is welcome.  

Saddle and nut look to be original, and don't appear to be worn.  Oversize replacements would give scope for cutting to compensate, if that is whats needed, so thanks for the pointer.  Fitting a compensated nut sounds like a good idea, as long as the current positioning is correct.

How would I contact Chris Alsop, should I need to ?  

I know precious little about acoustics, so new learning curve for me on this, so much easier sorting intonation on an electric, or is that just my naivety ?

As to acclimatisation, it has moved from Kent to Wiltshire to Shropshire in the last few weeks, and probably been case bound for much of it's life, judging by the lack of fret wear.  So that may be an issue, but probably nowhere near enough to cause the intonation problems I've mentioned.

I have no idea what the finish is, very thin, no grain filler, and matt / satin.  The mahogany sides look like striped silk, quite beautiful  

earwighoney

ChrisMusic said:

As to acclimatisation, it has moved from Kent to Wiltshire to Shropshire in the last few weeks, and probably been case bound for much of it's life, judging by the lack of fret wear.  So that may be an issue, but probably nowhere near enough to cause the intonation problems I've mentioned.

I have no idea what the finish is, very thin, no grain filler, and matt / satin.  The mahogany sides look like striped silk, quite beautiful  

12-53's should be fine without any problem for a 25.25" guitar, I'd recommend trying a few different sets of strings first to see if that would provide the intonation remedy. 

Do you have access to a decent headstock clip on tuner?  If you have access to one, I'd recommend trying to find exactly how much the intonation is out at the 12th fret (percentage of a semi tone).  If you've got a problem with the pickup output of the guitar then using a stomp box tuner might not give the most accurate readings.

Also, how wide (thick) is your saddle?  Depending on the how wide the saddle is (e.g. 2mm or 4mm), a decent luthier could compensate a new saddle depending on how much the intonation is out (no need for a overhang saddle).  That could potentially prevent the need for a new nut as well if the current one is fine.  

Here are the links for Chris Alsop's overhang saddle, and compensated nut. 

Do you have a humidity meter for you store your acoustic guitar?  Soundboards of really lightly built guitars are notorious for moving for changes to humidity issues.  I presume is it a very light acoustic guitar?  In the first post, the slight belly up issue could be the sign of a slightly over damp soundboard, which could be the problem there and letting the guitar 'dry' could sort it out.  Or it could be the saddle needs to come down a bit.

ChrisMusic

Cheers for the website details @earwighoney , that looks just like a potential solution  

The Intonation Modeller page/app he has looks interesting too.  I had a feeling that there would be something like the string end effect meaning that straight mathematical measurements would be a little misleading.  I'm not sure if that's the case here.  Now I just have to get my head around that effect's affect.  Some great resources surfacing in this thread, thanks chaps !

The saddle looks to be about 3mm0.  The nut looks and sounds fine, it is just intonation issues which are plaguing me right now.  What is it the Paul Reed Smith does to compensate with the nut ?  Move it forward or back ?

A deeply compensated saddle like the one you linked too will offset the string in relation to the slot in the bridge, do you think that will have any noticeable tonal affect ?  It will also change the break angle, especially as the pins are quite close by.  I am not sure if that would be detrimental ?  I think that the slight belly is probably just the moment of torque.

I may need to add a clip on tuner to by buy list, any recommendations ?  Although right now it would be solely for this task, I guess it wouldn't hurt to have one around.

And that's another no to the hygrometer, I always looked on guitars as tools, but maybe it's time to take a bit more care of them.  I take the basic view if it is too hot, cold, wet or dry for me, I wouldn't want my guitar going there either, maybe with the exception of the shower

As to weight, I thought my Blueridge 000 was pretty light when I got it, and it is, but that weighs more than the Dred, and the neck wood on this is a bit dense, so I guess the body must be lightly constructed.  I need to get out more ~ at least to play more guitars !  Comparison is probably a good thing, except it will probably lead down the garden path to the lair of the GAS monster, I have seen Lowdens skulking there    :o3

ChrisMusic

Any more answers or insights to any of the points / questions raised ?

Also while I am here, is there a simple resource for checking the fretting ?

ICBM

If you've got new strings on, the relief is OK, the nut height is OK and the bridge height is OK then it's really a certainty that it's the bridge position that's the problem. Why doesn't even matter than much, you just have to find a way to fix it if the problem is big enough that it can't be ignored.

The first thing I would try is a saddle with a compensated top edge, which is fairly easy to make yourself, or you can use the existing saddle if it's slightly too high anyway. You need to cut the top edge into two angled ridges, one running from front to back from the treble end of the saddle to the back halfway between the B and G strings, and the other running from the front at that point to the back at the bass end, like this:

http://www.strangeguitarworks.com/wp-content/uploads/2013/02/IMG_1220.jpg

Although I tend to make the top E position a bit further forward. The more complicated shape you sometimes see on factory-made versions isn't necessary.

(You'd think he could have found some nicer bridge pins!)

If that doesn't do enough you will need to look at the overhang saddle, or widening/moving the existing saddle slot.

ChrisMusic

Cheers ICBM,  I may just get a blank and some tools and give that a try  

I'm not too sure about the two bridge pins being half buried either !   I thought that the ball end was supposed to locate under the bridge, it looks more like it is on the end of the pins from that photo.

The break angle looks rather shallow too, but nicely shaped saddle, so a good illustration from that point of view.

** The reason I am asking about the nut**,  if I forgot to mention, is that the intonation across the first few frets is a bit (!) iffy too.  Nut groove height is fine though, leading me to think that it may well be contributing to the overall issue, and hence the question about checking the fretting distances and whether the nut is indeed in the optimal place.

ICBM

ChrisMusic said:

Cheers ICBM,  I may just get a blank and some tools and give that a try  

I'm not too sure about the two bridge pins being half buried either !   I thought that the ball end was supposed to locate under the bridge, it looks more like it is on the end of the pins from that photo.

The break angle looks rather shallow too, but nicely shaped saddle, so a good illustration from that point of view.

** The reason I am asking about the nut**,  if I forgot to mention, is that the intonation across the first few frets is a bit (!) iffy too.  Nut groove height is fine though, leading me to think that it may well be contributing to the overall issue, and hence the question about checking the fretting distances and whether the nut is indeed in the optimal place.

Yes, everything about that pic is a bit dodgy, except for the very nicely shaped saddle .


What happens to the overall intonation if you capo it at the first fret, tune it accurately (F-F) and then check the intonation at the 13th fret?

That would eliminate (or confirm) the nut as part of the problem, even if there is another problem at that end.

ChrisMusic

Capo ~ wazzat ???

I thought that was what my index finger was for !

Of course you are right, another thing for my to buy list then, and probably will only be used for this one task.

So is there another simple (& quicker) solution to save buying one ?  (apart from the maths that is)

Thanks for your help once again, much appreciated.  

ToneControl

ChrisMusic said:

Capo ~ wazzat ???

I thought that was what my index finger was for !

Of course you are right, another thing for my to buy list then, and probably will only be used for this one task.

So is there another simple (& quicker) solution to save buying one ?  (apart from the maths that is)

Thanks for your help once again, much appreciated.  

try this:
tune the strings open
check the tuning for the first 1-3 frets on each string
I think this should tell you if the nut  is cut badly

ICBM

ChrisMusic said:

Capo ~ wazzat ???

I thought that was what my index finger was for !

Of course you are right, another thing for my to buy list then, and probably will only be used for this one task.

So is there another simple (& quicker) solution to save buying one ?

A pencil and an elastic band .

You will need to double (or triple etc) the band to get enough tension, loop it round the pencil about halfway along, put the pencil across the neck with the end only just overhanging on the other side, and then hook the band on. A faff but it can be done. Worked for me at a gig when I forgot my capo!

It will cause much more serious tuning problems than a proper capo, but that isn't actually an issue for this purpose since you'll be retuning as precisely as possible anyway.

ToneControl

ICBM said:

ChrisMusic said:

Capo ~ wazzat ???

I thought that was what my index finger was for !

Of course you are right, another thing for my to buy list then, and probably will only be used for this one task.

So is there another simple (& quicker) solution to save buying one ?

A pencil and an elastic band .

You will need to double (or triple etc) the band to get enough tension, loop it round the pencil about halfway along, put the pencil across the neck with the end only just overhanging on the other side, and then hook the band on. A faff but it can be done. Worked for me at a gig when I forgot my capo!

It will cause much more serious tuning problems than a proper capo, but that isn't actually an issue for this purpose since you'll be retuning as precisely as possible anyway.

or get someone else to fret the first fret

ChrisMusic

ICBM said:

ChrisMusic said:

Capo ~ wazzat ???

I thought that was what my index finger was for !

Of course you are right, another thing for my to buy list then, and probably will only be used for this one task.

So is there another simple (& quicker) solution to save buying one ?

A pencil and an elastic band .

You will need to double (or triple etc) the band to get enough tension, loop it round the pencil about halfway along, put the pencil across the neck with the end only just overhanging on the other side, and then hook the band on. A faff but it can be done. Worked for me at a gig when I forgot my capo!

It will cause much more serious tuning problems than a proper capo, but that isn't actually an issue for this purpose since you'll be retuning as precisely as possible anyway.

Simple brilliance @ICBM , and so obvious once you pointed it out.  So, done with a permanent marker pen and a lot of elastic bands discarded by the local postman (why do they do that!).

Contrary to my old prejudices, I actually quite enjoyed playing using this makeshift contraption, so I may actually get a proper one eventually.  The old ones used to be little more than this, a piece of elastic and a rubber covered metal "nail".  And, yes, they did cause all sorts of tuning issues, awful things.  It is different when you do it yourself though I guess....  anyway...

~ ~ ~
All the intonation issues remained.

Measurements are a little inconclusive, probably down to ruler operator error !

Against the theoretical fretting measurements, the nut to 12th are pretty much correct for each fret, the 12th fret is at the halfway point along the 1st string, suggesting that there is no compensation applied to the bridge on the 1st string.  My measurements are not 100% conclusive on this, but with a foot rule calibrated in 10ths and dodgy eyesight (I really must get some new glasses) I think are pretty damn close.

The distance from the 12th to bridge along the bass string is 2mm longer, suggesting 2mm compensation built in.

The figures suggested by @AliGorie 's web link were 2mm75 for 1st up to 6mm6 for the 6th string, so this guitar could easily be out by around 2mm75 or so on the 1st string and 4mm6 out on the 6th, which is quite a bit.  The current distance from bridge crown to string pin hole is only about 7mm.  (I am not sure the 1st string is that far out though)

~ ~ ~
A good candidate for the compensated overhang bridge in @earwighoney 's web link.
Is there any tonal downside to using one with this severe an overhang ?

That's going to be some break angle though !
Will it cause other problems ?

~ ~ ~
Thanks also to @ToneControl , good suggestion, I really need to borrow, or even buy (!) a tuner with a cent readout.

On the subject of tuners, the piezo transducer is stuck on the underside of the top just behind the bridge, and out to a strap thingy jack.  Is there any simple way of getting it to interface better with my ST200 ?  I assume it is an impedance issue ?

I also still need to get my head around the compensated nut thing too.

So does all this make sense ?   Anything I missed, or messed up.  What is the best advise about what to do next ?
Oh, and thanks for all your help so far  

Lewy

Have you put fresh strings on this guitar yet?

ChrisMusic

OK @Lewy , full disclosure, I cheated !

I've replaced the 6th string, as that is the worst culprit, and I have a spare knocking around.  Slightly lighter gauge, so small but subtle change ~ intonation is still way out ~ so the maths is in the right ball-park IMO.

The intonation is especially interesting when you try the harmonic on the 7th, 12th and 19th frets, you get a real progression to an exotic microtonal scale !!!

So to my mind that's nailed the problem, it is just a matter of working out the best solution, and adjustment, from here.

I'm saving the whole set of new strings for a celebration of solving this dilemma.

Am I right to gather that strings are a whole new rabbit hole too  

Lewy

ChrisMusic said:

Am I right to gather that strings are a whole new rabbit hole too  

Only if you want to go down it. You could just as easily put the appropriate gauge of D'Addario EJ's on and never think about it again. It sounds like the finer points of acoustic timbre aren't the closest crocodile to the canoe in the case of this guitar.

ChrisMusic

Crocodiles ?    Canoes ?     :-O

 When I signed up for this, nobody told me this journey was going to be a wildlife adventure, where something could have my leg off at a moments notice !

 ~ but if I incapacitate the nearest croc...
     ( movie running in my mind... ChrisMusic, the new Crocodile Dundee ! )
Then the next one waiting to take my leg off immediately after, is probably named "tonal grail quest" !

...at least as far as this guitar goes, and I think it has the potential to be a very nice guitar once this is sorted. I am still "getting my ears in" on this current acoustic journey, but it does have a lovely complex sound and sustain.  Although it is a very early one, the maker is quite sought after and highly regarded, I just wish he would answer my eMails...

Having said that, it is a lovely challenge to solve this between us here IMO.  I have learnt a lot so far, knowledge and understanding are always valuable, and sharing is what makes this place so great.  It will all stand me in good stead for the next guitar(s) too...   "the safari must go on"

Just as long as the crocodiles don't get an early dinner, and I have a leg (or two) to stand on !  

ToneControl

is the bridge saddle inserted the wrong way round?

Lewy

ChrisMusic said:

Although it is a very early one, the maker is quite sought after and highly regarded, I just wish he would answer my eMails...

Is it a dreadnought by someone beginning with A by any chance?

Because if it is (an early build from a british luthier sold on here a while back) it means there are pictures and a video on this very board which would be useful to the folks trying to help you out.....

Lewy

And if it IS that guitar I think I can see your problem....the saddle isn't the original (there's a gap in the slot at each end), and looks like it's got a forward lean on it (it's supposed to be perpendicular to the top) - probably because it's not well fitted to the slot.

Obviously if it's not that guitar, please ignore!

ChrisMusic

Top marks for your sleuthing skills @Lewy , yes it is indeed.

I didn't want to name the maker publicly if there were any issues which would cast any shadow on his name, for obvious reasons, but your last post suggests that the intonation issue is a simple matter of someone else's inappropriate changes, which sits fine with me, and is easier to address.

As to photos, I didn't realise any were available.  I couldn't access the goo.gl link.  I don't know why I always get a blank page with no content ?

How did you access the video, I would love to take a look (maybe PM me?).

I have only just collected it, although the deal was done some time ago, a house move and transfer via a local family member kept the anticipation building.  Nice easy transaction and lovely chap to deal with.

I thought that I saw a similar "forward leaning saddle on a Lowden, or am I mistaken, so I thought that it was correct, my bad.  You are right about it being a later change, not only does it not fit right across, but the finish is non consistent with the guitar's build quality.

Why do you think someone would have done this ?