Tuning pegs, machineheads, tuners, tuning machines, those turny things at the top of the guitar. Machineheads are referred to as many different things, and for all the names that people call them there are just as many different types on the market today. Many machineheads have variations in their appearance and how they function so deciding on which set is right for you can be quite baffling if you’re not quite sure what you’re looking for. Changing your guitar’s tuners is a popular modification many players often make due to damage to their current set or due to wear and tear over time.
Many of the replacement machineheads on the market retain vintage aesthetics but often make improvements on the humble machineheads shortcomings in functionality and durability. For instance, over time many older tuners can suffer from gearing issues. The gearing on vintage tuners were made of lesser wearing metals such as brass (instead of steel) and not machined as well as they are today either. The quality of gearing of your tuners plays a huge role in how well they operate and worn out gears can struggle to hold a string’s pitch. String slipping is another issue that can occur and modern improvements on the humble tuner such as locking tuners can help alleviate this issue.
String posts can become wobbly over time as can the knob shaft. Backlash is another common ailment of older tuners. This term refers to the amount of free play felt when a button is turned from one direction to the other before the tuning post begins to turn again. Backlash is especially noticeable for players that use the tremolo and bend their strings a lot. These two aspects of playing create greater movement at the tuning post and doesn’t always result in the string returning back to its original pitch.
Unless you have your heart set on a completely new design of machinehead, it’s recommended to source a set of tuners that are similar in design to your current set. There are a few reasons for this; firstly, if you are replacing tuners that have been on a guitar for a long time, once removed, there may be some discolouration between the lacquer which has been exposed and the lacquer that had been covered by the tuner. If you opted for completely different shaped machineheads, you may find that the new sets’ footprint won’t necessarily cover the discolouration, so it may look a little odd.
Secondly, when you buy new tuners, making existing holes larger for new tuners can be a necessary evil. For most people drilling new holes in their guitar isn’t the most desirable thing to do unless it’s necessary. Choosing a similar design will help keep this to a minimum. This is especially important for vintage instruments. Replacing a vintage guitar’s tuners with a different design may not necessarily be in keeping with the guitar’s original ‘vibe’ and if the guitar is worth some decent money, it could harm its market value if you chose to sell the guitar on at a later date.
One of the first things to bear in mind when buying a new set of tuners is the layout of the tuners on the headstock. The most common types are 3-a-side and 6-in-line configurations. For example, Fender Stratocasters or Telecasters adopt a 6-in-line configuration as all six machineheads are mounted on one side of the headstock, whereas for a guitar like a Gibson Les Paul, it has 3 tuners mounted on each side, which is commonly referred to as a 3 + 3 configuration, or 3-a-side set.
Furthermore, some guitars have different layouts to the standard 6-in line or 3-a-side configurations. For example, some have four tuners on one side with two on the other such as the Sterling Stringray by Music Man pictured to the right. As you can see the E, A, D and G string tuners are mounted on the bass side of the headstock, whereas, the B and high E tuners are mounted on the treble side.
This may see like an obvious point, but it’s worth noting that there is a difference between machineheads made for right-handed and left-handed guitars. This is primarily applicable for guitars that have a 6-in-line configuration. The design is mirrored between right-handed and left-handed machineheads as these are mounted on a different side of the headstock. This point is also applicable to guitars with reverse-headstocks too.
One other element to consider is how the tuners are mounted to the headstock. The main body of a machinehead needs to be secured in position at the back of the headstock to prevent it from moving around. Depending on the manufacturer’s design, they can be mounted in different ways. Most commonly machineheads are fixed to the headstock using a small screw which is supplied when you buy them. It’s important to be aware of where the mounting screw flange is located on your current set as there are variations in it’s positioning. This can be straight underneath the tuner, but some sit at a 45 degree angle and some can be off to one side at a right angle.
Some tuners don’t make use of a screw to fix the tuner to the headstock at all, instead, they use a pin that is located on the machinehead casing (see image below). This pin braces the tuner as it sits in the headstock and prevents it from moving about. Most commonly, machineheads that adopt the pin design will use one pin, however, some tuners do have two pins such as the Fender Deluxe Machineheads.
On some guitars with a 3 + 3 configuration, the tuners may be mounted individually or they can be mounted on a rail with 3 of the machineheads fixed to a plate sitting on each side of the headstock. This design was particularly popular on (early Gibson guitars) but they’re still available today. Each plate is held in place with several screws and if you are looking to replace your current rail tuners, it’s worth bearing in mind the distance between the screw holes. You’ll find most reproduction tuners will use the same screw spacing but it’s just something to be aware of.
If you are able to find tuners that are direct replacements for your current set and utilise the current holes in the rear of the headstock, if possible, it’s a good idea to mount the new set using the screws and bushings from your old tuners. This will help prevent any cross threading occurring or having to potentially make adjustments to the current holes.
The bore hole refers to the size of the six large holes in the headstock which allow the tuning posts to pass through. The bore hole’s size will usually depend on the type of bushings used to hold the machinehead in place from the font of the headstock.
Machinehead’s bushings secure the tuner in place from the front of the headstock. There are commonly two types of bushings; push- in (or press-in) and bolt threaded bushings. The press in style bushings are more commonly seen on vintage style tuners and require a smaller bore hole in the headstock. Bolt style bushings are seen on modern style machineheads and were introduced to maintain better support for the tuner shaft. The threaded bolt bushings are often larger than the push-in type and consequently require a bigger bore hole to accommodate them. If your guitar has had tuners with bolt bushings on and you are looking to return to using vintage style tuners, you can source conversion bushings to make the bore hole smaller, thus stopping the vintage sized tuners moving about excessively in the larger holes.
As well as improvements to functionality, retrofit tuners on the market offer a variety of finishes such as nickel, chrome, satin chrome, black and gold. Generally speaking, nickel and chrome finishes tend to be more popular and also cheaper than black and gold designs. If you have a vintage guitar it’s worth being mindful that the finish on a new set of tuners will be a lot brighter and could look a little ‘out-of-place’ but there are methods out there to age your guitar parts to give them the more vintage vibe if you felt the need. In the image to the right, although both finishes are similar, you can see the slight variation between the vintage (slightly duller) nickel finish on the left and the brighter 'mirror-like' chrome finished machinehead on the right.
Many tuners’ specifications will include a tuning (or gearing) ratio. This figure usually ranges between 14:1 and 18:1 and is based on the tuner’s two gears. The ratio represents how many turns of the smaller (worm) gear it takes to turn the larger crown gear (tuning post) by one complete revolution. The higher the ratio, the more turns of the button are needed, however this does provide greater tuning accuracy. Bass tuners will typically have a higher ratio as standard of around 20:1 to 24:1.
On older tuners, the gears are exposed and do not have a casing around them, whereas nowadays, unless tuners are designed to replicate this vintage look, they are usually enclosed. This can give a sleeker look but also prevents dust and debris collecting around the gearing which can be detrimental to the tuner in the long run. Most modern tuners are die cast and their gearing is completely sealed which avoids any lubrication issues for their entire lifetime.
The purpose of a locking tuner is to aid tuning stability by preventing the string from slipping. They also make restringing a doddle as you don’t have to wind the string all the way round the post like you do with non-locking tuners. Locking tuners are becoming more popular nowadays but tend to be more expensive than the non-locking counterparts.
One of the most popular types of locking machinehead use a locking wheel mechanism on the back of the tuner. This wheel controls a small retractable post that sits within the main tuning post. When a string is threaded through the post, turning the rear wheel causes the internal post to rise up and effectively ‘pinch’ the string and lock it in position. From there it’s a simple case of tuning up. You can see how this mechanism works in the image on the right hand side. Notice the hole in the shaft when the wheel has retracted the inner post down the shaft.
Other manufacturers such as Gotoh and Tonepros use different methods to lock the string. Some will use a top locking method where the string is pinched using a cap that screws in the top of the post.
One other aspect of machineheads you may need to consider is whether or not you would want (or need) vintage or modern style posts. The original Kluson machineheads used on Fender Stratocasters had a slot in the top of the post with a hole running down the centre of the shaft. The string is placed down this hole before winding, whereas, what is more commonplace with modern post is threading the string through the post. The slotted vintage style is still popular today and many players prefer the design for their vintage aesthetics but also because they can make restringing easier. They are a little neater (not to mention safer) as the trimmed end of the string is hidden from view and doesn’t stick out so won’t catch your fingers (or tear up the inside of your gig bag).
Staggered tuning posts graduate in height between the low E and the high E. Machineheads with staggered post heights are typically found on guitars that without a pitched (angled) headstock and don’t make use of string trees. Their main purpose is to help create a good break angle for the string between the nut and the tuning post. Without a suitable break angle, the string won’t have enough downward pressure on the nut which can result in a loss of sustain and sometimes fret buzz. The string may also be prone to popping out of it’s slot too.
There are as many different button shapes and sizes on the market as there are designs of tuners nowadays.
Variations come in colour, the material of the button (usually steel or plastic) and how they are fixed to the main body of the tuner. The steel buttons are usually screwed in whereas the plastic buttons are often simply pushed on. Plastic buttons that were used on older guitars can rot and split over time. Whilst these can be difficult to remove they can be replaced if the machineheads mechanics are still intact.
Certain buttons are solely used on specific machinehead designs in order to maintain and replicate older designs. For example, the plastic tulip button design is still used on many Les Pauls to replicate the appearance of older style machineheads.