Wednesday, October 8, 2014

Guitar Necks-what you didn't know.

Been away from blogging for a bit. Sorry about that. Just been extremely busy. Guess that's a good thing.

Today's blog is going to be about guitar necks. That means everything from the machine heads to the material the frets are made up of. Ready?? Okay, here we go:

The most important part of any guitar is the neck. I will repeat that. The most important part of any guitar is the neck. So let's talk about acoustic necks for a bit.

The neck is responsible for a lot of the tone the instrument produces. How does that happen?
Well, it actually starts in the headstock area of the instrument, right at and after the machine heads. (tuners)
When a guitar is strung and the strings are pulled to tension by the machines, there is a lot of tension produced, transferred though the machines and into the headstock. This is coupled with the tension produced at the nut and makes it's way down the neck where again it is coupled with the fret transfer, into the fretboard and then channelled into the dovetail block, or however your guitar neck is fastened to the instrument.

Newer acoustic guitars can also be bolt on necks, where the neck is fastened into a mortise and tenon joint by the means of two machine bolts. Inserts are installed into the neck. These align with holes in the dovetail block, usually 5/16” or 6 mm and two allen head cap screws are countersunk into the block to fasten the neck to the guitar via the neck inserts. This provides a nice tight joint and I believe to be as good as any dovetail joint on the market. The nice thing about this type of joint is that it can be easily dis-assembled so as to reset the neck, or service or change frets without the work required to steam off a dovetailed neck.

The old standard is the dovetail. Gibson, and Martin still use this means of attaching the neck to the instrument. Whereas newcomers like Josh House, Richard Paxton, and most of the Godin line of instruments as well as many others prefer to use the bolt on method.

So why the dovetail? Tradition, basically. Martin have not changed their basic guitar design in over a hundred years. For that matter, Gibson is right behind them. Even though most guitar necks, electric and acoustics are CNC milled these days, there is still a preference by the aforementioned to maintain consistency in their original design. Hence, the dovetail joint. Even the Blueridge guitars, a direct copy of a Martin dreadnaught still utilizes the dovetail. It just works!. Some would argue one over the other, to me I am more preferential to the bolt on. I don't believe there is much difference in tone. If there is any, it is negligible.

If one has ever had to try and remove a dovetailed neck on a guitar in order to do a neck reset, I believe you would agree with me, bolt on is better.
Remember, the more contact with the body, the better the tone.
So how does this change the sound of the guitar?

Well, we talked about how the sound gets to the dovetail block on the guitar. This block is part of the front of the guitar and is what the neck attaches to. Some are larger than others. Some are made of rosewood, while others are birch, maple or just plain spruce. The sound, and mechanics that are transferred into, and through this block, make their way to the sidewalls and soundboards on the instrument. It is this combination of wood, as well as the neck, that give the guitar it's distinct tone.
Remember, tone and volume are two very different entities when you are talking acoustic sound.

Volume is basically what comes out the sound hole, it is what is produced through the bridges plates being sandwiched onto the soundboard. Much like the volume knob on your stereo. You want it louder, you strum louder. Just like turning up the volume.

Tone however is a bit different. Tone encompasses all of the other things I just spoke about, the machine heads, type of neck material, type of nut material, fretboard material, (rosewood, ebony, ???) fret material and makeup. Dovetail attachment, bolt on? Dovetail block material, sidewall material, rear soundboard material, top soundboard material, type of bridge plate material, sub plate material, saddle material, bridge pin material, thickness of the soundboard. This is like the graphic equalizer on your home stereo. It's what makes the bass exactly what bass should sound like and the mid range and high end stand out and take notice as well.

When the tone is married with the volume of the instrument, it is really something beautiful.
The other thing to mention about tone is that as a guitar's tonewoods mature, it only appreciates in tone and in most cases, value as well. There were only three Martin D-45's built in 1933. The first year they were introduced to the market. Why do you think a guitar that was probably built for one hundred dollars back in 1933 would be worth in excess of $500,000.00 now. They still build the D-45. Sure, it's a rare guitar, but why do you think everyone would want to have this instrument? It's the tone!!

On the subject of guitar necks, there are builders who believe a three or four piece laminated neck is as good as a solid one piece.
Well, there's a good argument. I am all for saving the planet and cutting back on waste when it comes to being more resourceful on acoustic building, but I personally believe whenever possible, choose the one piece neck. Again, it's a matter of tonal preference, and it's what your ear hears. Still, I don't believe that when you glue a bunch of pieces of would together, there could possibly be the same tonal frequencies, vibration and transfer as there can be using a one piece neck.

Most neck materials are consistent, and with acoustics the choice is usually select mahogany for the neck and headstock, and rosewood for the fretboard. Why these woods? Tone! Straight and simple. It works, and everybody uses it. Now differing builders of late offer a myriad of differing tonewoods for both neck and fretboards. Personally, I am with Martin and Gibson on this one. If it ain't broke.....
You want to be very cautious using exotic woods for fret boards. Most do not stand up and can't even come close to the old standards. I have seen in my shop, brand new instruments with fret divots and fret wear, and only on their first set of strings. And we are talking some high end instruments here. Stick to what works.
What about an ebony fretboard? Actually, I love ebony. I love the play and feel of it, and seldom do you have a problem with frets popping due to inconsistency with humidity, or dryness. Ebony is a great choice. It wears better than rosewood, requires less maintenance and works well with the frets. The only thing about ebony is, if you are a luthier like me, and you have done a lot of fret jobs, ebony is not the best wood to be working with. It is like glass, and must be treated accordingly. Hard to remove frets without 'galling' and slot damage. In most cases, frets have to be glued back into place because they simply won't hold in the slots. Ebony, not a good friend of guitar builders.

Some necks are finished with either a light wipe on polyurethane, nitro-cellulose, varnish and sometimes paint, and guessed it, affect the tone and playability. I often wondered why some builders would spend so much time building a neck, and then cover it up with paint and clear coat. What are they trying to hide?
What else affects tone? How about the truss rod? The truss rod is an important part of any guitar neck, and it also affects the tone of the instrument based on what it is made out of. Anything that transfers sound and vibration on the instrument, affects tone.
Martin did not even install a truss rod in their guitars before the mid eighties. Now why do you think that is? Well, if you don't have a truss rod, and it's a basic steel re-enforced neck, there would be more room for wood. And more tone. Martin was onto something. Problem was, they couldn't be as selective about their neck woods and the cure factor when their guitars were in such demand. They had to start using woods that were kiln dried and not air seasoned, like they were famous for this wood, though not totally dry, twisted and caused Martin to have to come up with a workable solution to a problem that Gibson was very familiar with. So Martin, like Gibson, started to install truss rods in their guitar necks, so that when a neck adjustment was required, it could be easily made, with little or no consequence to the sound of the guitar.

Now let's move onto two other important neck and tonal variables. #1, nuts. What is the best nut material out there today? Well, there are all kinds of differing materials. There is plastic, steel, brass, TusQ (man made bone) graph tech plastic, porcelain, ebony and other exotic woods, and finally 'bone'. Usually beef shin bone, but I have had great experiences with moose and deer shin bone as well.

Again, there is personal preference here. I would have to say that my favorite is still bone. I am more preferential to composites for some bridge saddles, but I have used bone there as well many times. Just a personal preference. It's easy to work with, consistent and always provides great tone, if you can get past the smell.
#2, Fret Material / size. Gibson uses a jumbo fret on their electrics and has used this same fret on some of their acoustics as well. Fret width, height, tang depth, as well as the material blend makes a big difference in the sound of your instrument. Frets are usually made up of a high grade of stainless steel at gr. 316 or better, but what matters in making them last longer and have increased tone and harmonics, is the alloys that mix with the stainless that provide consistency and long life. Carbide,(carbon) tungsten, bronze and others are just some of those additives.

Still, frets cannot be that hard that they can't wear at all. If they were, your strings would be breaking all the time because of the fret memory on them. Eventually wearing through and breaking the string. Some companies, like MusicMan use a 100% stainless fret, and when coupled with their ebony fret boards, and Ernie Ball 'Cobalt' strings, work very well together. Actually, one of the best combinations I have ever worked with.

So, I guess that will be it for this round. Next time we'll talk about electric guitar necks.
So long for now.
Remember, it's all about the tone baby!!

Brett McNaueal / Luthier
Brett's Guitar Works / Trenton, Ontario / Canada

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