Saw a blog today by the demo dude Andy on Proguitarshop on this topic that was interesting enough that I figured I'd share here. Enjoy!

ProGuitarShop.com
5/3/2011
Andy's Corner (blog)

Neck Construction

Hello folks. Welcome back to the Corner. This week we’re going to look at necks. How is a neck built? Why do some guitars have string trees and some don’t? Set neck or bolt-on? These are some of the questions we hope to answer in this installment as we explore the variety of construction techniques used for creating a functional neck for a guitar.

When building a guitar neck there are several factors a builder takes into consideration. One of the first is quarter sawn or flat (slab) sawn wood. If you’re unfamiliar with the difference in these two cuts we’ll explain. A flat-sawn neck has the grain of the wood running mostly parallel with the fretboard while a quarter-sawn neck grain is running perpendicular to the fretboard. Here’s a great photo of the difference:

Grain Types
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So how does this affect the guitar? Well, a quarter-sawn neck ends up being a stiffer cut so the neck can withstand more tension and tends to stay more stable. This results in a neck that once set up will usually require less maintenance and fewer periodic truss rod adjustments as it will hold the neck angle better under changing conditions. A slab-sawn neck has more flex in the direction of the string pull and therefore may require adjustment more often under changing conditions. Now, that being said, most problems that may be found with slab-sawn neck conditions have been counteracted with the use of an adjustable truss rod. As you know the truss rod adds stability to the neck as well as the ability to adjust the neck to counteract string tension. Aside from stability, most people will agree the direction the wood is sawn also adds some tonal color. From what I’ve learned and read, most people feel that a flat-sawn neck has a mellower tone with a “looser” low end whereas a quarter-sawn neck tends to be brighter and more articulate with a tighter low end.

Quarter-sawn wood tends to be pricier than flat-sawn due to the nature of the cut. More flat-sawn necks can be cut from a tree than quarter-sawn since more of the actual log can be used and cut. Since the expense can be fairly large, another way to add more stability to necks and get that rock solid feel and tone is to use multiple laminates. In this case a builder might take two or three thinly cut, slab-sawn blanks, stand them on end and glue them together. This creates more stiffness than a traditional slab-sawn neck by changing the grain angle to perpendicular and uses less specialized wood cuts since regular slab-sawn pieces can be used. This also allows the builder to add different woods to the mix for stability and tonal changes. For example, this Alembic neck pictured below features Western Maple outsides, Purpleheart laminates, and a Cherry center piece. This adds not only stiffness and stability but possibly adds some unique tone as well.

Laminates
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Glue or Screw?

So another hotly debated topic in guitar construction is the neck joint. There are three main types of neck joints, set-neck, bolt-on, or neck-through body. Each has its own contributions to tone and playability.

Bolt-On Necks

A bolt-on neck design is exactly what it sounds like; the neck sits in a “pocket” routed out of the guitar body and is held in place using bolts or wood screws. Bolt-on necks were introduced in electric guitars by Leo Fender with the Telecaster. A lot of people believe the bolt-on neck of the Telecaster was introduced to make mass manufacturing easier and to save on cost, the truth of the matter is much more utilitarian. Leo was a practical man and as such wanted his instruments to be practical as well. His thinking was if there is a problem with one part of the guitar (such as the neck) it could easily be taken off and replaced by the musician without the need for expensive professional repair.

When built properly this method produces a solid “wood-to-wood” point of contact between the neck and body. While a lot of people seem to think of this as the “cheaper” option, a properly designed bolt-on guitar is as difficult if not more difficult to build than a mediocre set-neck guitar. A very important aspect of the bolt-on design is the fit of the neck in the neck pocket. A loosely fitted neck pocket can yield undesirable results such as poor sustain, lack of overtones, and unstable tuning and intonation. A nice, tight neck pocket will keep the vibration transference from neck to body smooth with less decoupling as well as keeping the guitar stable.

Bolt-on necks tend to produce a snappy tone with a quick attack and a slightly delayed note bloom. This is because the neck joint actually decouples the strings from the body and the neck resulting in slower acoustic transference. This is the snappy “twangy” tone so often referred to in a Telecaster or Stratocaster. The attack tends to jump out of the instrument quickly while the note blossoms behind it resulting in the poppy type of sound one might get from the neck pickup in a Strat. While more attention to the neck pocket can result in quicker transference, this is not always desirable for some people.

Set Necks

A set-neck design employs the use of glue to make the contact between body and neck. Different build methods are used for this depending on the age, builder, and type of instrument. Gibson used to employ what is referred to as a long tenon neck joint where a long extension came out from the neck that sat tightly in a pocket in the body where it was glued. This allowed for lots of surface contact and a very solid joint. Another popular joint is a dovetail joint. This is a block of wood extending from the neck and fanning out that sits into a pocket in the body that has angled sides. This method also allows for maximum wood-to-wood surface area and is also a strong connection between body and neck.

Set neck guitars in general (and again, this refers to a good quality build) have a faster transference than a bolt-on joint. While this yields more sustain and resonance, the note attack suffers resulting in a warmer, smoother overall sound with quick note bloom and great sustain. This type of neck joint is great for chunky rhythm sounds, fluid leads, and big round jazz tones.

Neck-Through-Body

A neck-through design is when the neck extends through the bridge. This is accomplished by cutting the neck and middle portion of the body out of one piece of wood or wood laminates. The remaining body “wings” are then glued to the outside of the body. The neck through design yields the maximum transference and acoustic coupling of the strings to the instrument resulting in nice sustain and lots of woody resonance in the sound. Many builders feel that this is the best possible way to maximize tone and sustain. A guitar of this design will usually also have easier upper fret access due to the lack of a neck joint. The downside to neck-through design is that it is much more time consuming and expensive to build and is therefore mostly only found on high-end instruments.

These three designs, while differing greatly, have their own advantages and disadvantages but also each have their own unique sound and playability factors. The best bet when choosing between them is to once again trust your ears of course but also trust your hands and fingers. Find and play a few of each style and once you find one you’re comfortable holding and playing, listen to it and see if you hear what you want to hear. As always your best guide is yourself.

Headstock Angle

Now a very common question we get around the shop is regarding string trees. Why are they there? Why do some guitars not have them? The string tree was introduced to increase string angle or “break” angle on the nut in order to keep the string from coming out of the nut slot. These were needed on guitars that had a flat headstock (in relation to the neck) like a Stratocaster or Telecaster. Some guitars manufacturers like Gibson angle the headstock in order to give enough of an angle to keep the string from slipping thus avoiding the need for a string tree. Another way to increase the break angle on guitars with a flat headstock is by using staggered tuning machines. Starting with the low E string, the height of the tuning machine reduces until by the high E, the hole for the string is right above the wood of the headstock thus increasing the angle of the string as the tuners move further from the nut. This avoids the necessity of having a string tree. Most guitars with a flat headstock will have a string tree or sometimes two installed.

Example of a flat headstock with string trees.
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Example of an angled headstock without string trees.
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So there’s a nutshell full of neck info. As always we believe that a guitarist should have working knowledge of his/her gear in order to make good choices when purchasing, replacing, or having it repaired/modified. Knowing a bit about the neck of a guitar is a must when faced with all the options available out there. As GI Joe says, “Knowing is half the battle.” Thanks for reading folks and we’ll see you next time, in the Corner.

Fady

El Mirage @ ReverbNation