I have a client who wants to sell one of these two guitars and I want to help him.
https://www.guitarristas.info/anuncios/gibson-byrdland/941285
https://www.guitarristas.info/anuncios/gibson-l5-lee-ritenour/899888
You can follow the links above or you can leave me a contact number or email address and I will pass it on to the seller. johnguitar(at)johnguitar.com
Hello again. First I want to clarify something I said in the previous letter. A guitar’s reaction to the strings being played is a a reaction of the whole system and so it must work together. However, the most important subsystem is the top and its bracing. I am not suggesting that you mix and match body styles with top bracing but whatever you do, don’t change the top construction until you have made a few that sound pretty good. And only change little things from there in subsequent guitars. The plan you have of Hauser is from 1943 and I want to remind you that it used thicknesses in line with 20th century spanish guitars while Courtnall’s model may be considerably thicker. When you choose the model keep in mind that small templates work very well. This allows you to leave the top a little thinner while a larger template causes the top to yield more if it has that same thickness. In answer to your question about the width of the sides, 85-90 is very narrow and the reaction of the guitarists to a thinner body is not always positive. However I have made most of my instruments with those measurements and have found some who prefer it. I use a reinforcement under the bridge on the classical guitars I make but it is very narrow and triangular in section. I don’t think it makes much of a difference whether it is flat and wide or long and narrow though. In the historical copies I don’t use reinforcement because the old guys didn’t use it. I think the bridge glueing system you are going to use is important. If you use a countermold inside to glue the bridge on try it with no reinforcement but if you are going to glue with pressure or weight, the reinforcement facilitates everything.
One of the aspects of the guitar where I am very clear that there is only one good way to do it and I am not interested in the blueprints is in the shape of the neck. The first guitar I made has a non-round neck profile – what they call D instead of C. As much as this shape seems comfortable at first due to the good support that the thumb has, as soon as you play for a while the hand gets tired because it is only comfortable with the thumb on the flat part. However, for certain positions the thumb is usually moved to other angles of the neck. The neck should have a round section so that the thumb doesn’t register changes as it moves.
Regarding the construction of the neck, I use the integral neck with cuts to insert the sides, I no longer make the neck separately to fit the body as I did with the first ones. Another thing that I stopped doing after the first guitar is reinforcing the neck. There are two ways to make a neck: We can make the neck straight and allow for it to yield minimally to give us a very slight curve or we can reinforce the neck and fret it in such a way that it has a minimal curve once finished and that nothing yields. I do the former and instead of reinforcing I choose the cedar very well. Neck stock thickness is important too. When you prepare the neck blank you have to give it the right thickness so that you do not have to work too much with the spokeshave, knife and rasp but at the same time that the head and heel joints do not fall close to the plane on the back of the finished neck. We don’t want the joints to be long and ugly. I have seen guitar makers who prepare the neck with a different thickness in the head joint compared to the heel joint so that very little thickness has to be removed from the neck. I don’t do it like that. What I do is, once the head is cut, I thin it so that it has the final thickness before gluing it. If you have the tuners, you can now measure the plate to calculate the desired head thickness, but it is convenient to make the head for a final thickness of at least 20 mm including the headplate so that the plates of the tuners are not very close to the edges. The head angle on my guitars is 14º but on some of the older ones I have examined and copied it is 18. For the neck itself 20mm is more than enough.
If we talked about design the other day today we can talk about the architecture of the guitar. My first teacher used to say that acoustics is the resolution of the structural problems of the instrument. I would add three ideas to this theory. First, the good guitar maker tests changes in construction on a very small scale to try to get the sound or other characteristic that he is looking for. Modify a thickness or reinforcement and once its effect has been verified, decide to incorporate the change or reject it. It is important to only make one change at a time. If the guitar maker does not have enough experience, he must have musicians willing to give their honest and reasoned opinion. It is not easy to find this “advisor” as we may run into someone who leads us down the wrong path and does not help to improve the guitars. Not all guitarrists know what they are looking for in an instrument and can be completely objective. Don’t forget that precisely because the guitar market is small, you have to fit in with what a majority of guitarists are looking for. You might need more than one player to advise you. Second: the evolution of the guitar and its result is a good path, we have come to this because it works well as an instrument. For this reason, I always recommend that the personal evolution of a guitar maker begins with a consolidated model. If you do not have available a well-recognized guitar as a reference to copy at least you can resort to using the measurements of those guitars. Torres and Santos Hernández are good references. At the beginning I used Hauser and Fleta plans and discarded the Fleta. The heavy bracing of that particular guitar didn’t work for me at least with a spruce top. The personal path of the guitar maker is long but having a base that we know can work allows us to make the changes little by little that makes your sound your own and corrects the mistakes that you yourself have introduced when interpreting the master guitar-maker. Third: We have arrived at this guitar model by relying on those who came before; centuries of evolution. We cannot discount all that they learned and the knowledge they left behind. The same happens with those who study today. More and more guitar-makers offer their experience of how changes in the structure affect the guitar’s sound and playability. If we can judge for ourselves the reliability of this information and rule out the bad, what remains can be a great help. Jeffrey Elliot, Trevor Gore, David Hurd and Alan Carruth spring to mind as makers who have done a lot of research and shared it in different ways.
As may be obvious from reading these articles I am trying to include advice for beginners along the lines of “how to build your first guitar without getting it wrong”. Regarding the thickness of the back and sides, stick with the measurements of the original, there will be time to try other things. It matters much less than other things like bracing, doming, and of course the quality and thickness of the top. I do usually stay at 1.8 for the sides and 2.2 for the back. When I make copies of historical guitars I measure the guitar and use the original measurements.
A friend called me up yesterday for some advice on guitar-making: both specific and general. I don’t know if I will publish everything I write for him but it might be a good idea to post here what I have to offer him as I go along. The first thing I want to comment on is how little I like modern guitar trends. This might keep me from being very useful when talking about soundports and alternative soundholes which is a pity because this is what he first asked me about. However, I can talk a little about design and the limitations that tradition imposes. Design is the most difficult thing there is and the bad design of many guitars is very noticeable. Traditionally, we are only free to choose the woods, the purfling, the rosette and the headstock. Logically there are a finite number of headstock designs if we respect the tradition of symmetry and the fragility of wood. Inlays and carvings greatly expand those possibilities. However, the big problem is to make something not only original but also harmonious and aesthetically pleasing. A good option is to copy the headstock of some old and famous guitar maker. Of course as soon as you feel like you can design something yourself you should go ahead and do so.
Rosette design has the same problem in that it can be screwed up in many ways. Using bright colors is very dangerous; large tiles can look very rough, and very fine tiles can lose their definition at a distance. A great rosette looks good up close but also makes an aesthetic statement a few metres away. Here there are also some modern trends that seem very ugly to me, such as man-made materials and large pieces of wood. We can use a rosette from the old guitar makers but another good option is simple purfling strips. Do you remember Antonio de Lorca?
As for the design of the guitar in general, the closer you stay to tradition the less design work you have to do. For me design is a real struggle so there is no way I would try to change the shape of the bridge, the soundhole or the guitar itself in any major way. Besides, if what you want is to design a new instrument you’ve come to the wrong place.
I am thrilled to hear that korean guitarist Honam Ji has recorded an album using a guitar made by me. I don’t think it is available outside of Korea just yet but this video sounds great. 
