Guide / GUITAR LAB
Servicing an acoustic before amplification: frets, nut, saddle and pickup. Thumb LF-20
How should you plan servicing for a guitar you want to amplify? Using the Thumb LF-20 as an example, we show why it is worth discussing the condition of the instrument and your expectations of the pickup separately.
Two goals in one job
Preparing an acoustic for playing amplified is best started with a conversation about the instrument itself. Does it play well? Does it need work on the frets, the nut or the saddle? After that, you can define your expectations of the pickup and how you will use the guitar.
These are two related but separate areas of work. Installing a pickup system is not a refret or a nut and saddle fitting service. A clear plan makes it possible to establish what needs to be corrected on the instrument and what is to be added to its equipment.
A Thumb LF-20 from our workshop
The Thumb LF-20 received new frets, a bone nut, a bone saddle and bone bridge pins. We also presented it with an SVG Sound Research piezo pickup. You can hear this instrument in the recording.
The Thumb is a good illustration of what should be covered in the conversation before the job: the condition of the playing surface, the parts that support the strings and the amplification method. Each of these points is worth agreeing on separately.
A new nut has to be fitted
With the nut, we check how it seats in its slot, the string spacing and the dimensions of the string slots. The final height check is done on the instrument in tune. A ready-made part of a similar shape will not necessarily suit a particular neck.
That is why, when describing the service, it is better to talk about making or fitting the part rather than simply swapping one material for another. This makes it easier to understand what the luthier's work actually covers.
The pickup and the input you plug it into
With a passive piezo pickup, it is also worth checking how well it matches the input of your amplification. A suitable preamp can provide the right conditions for working with this type of pickup. That is why the whole signal chain matters when choosing a solution, not just the part installed in the guitar.
Before buying or installing, check the documentation for the system you have chosen: whether it includes a preamp and what kind of input it is designed to work with. Individual systems differ in design; the term "piezo" alone does not describe everything they include.
How to prepare for a conversation about amplification
Tell us whether you plan to play on stage, record at home or use amplification only occasionally. Describe the gear you have and what you expect in terms of ease of use. The installation method and any modifications to the guitar should be agreed for the chosen solution, not assumed to be the same for all piezo pickups.
Three bone parts, three separate jobs
On this Thumb, the nut, saddle and bridge pins are all bone. Using one material for all three was a choice for this guitar, not a rule.
Each part has a different role. The nut guides the strings at the headstock end, while the saddle supports them at the bridge. The pins help position the strings so their ball ends seat against the bridge plate inside the body. The fit of each part must suit the instrument.
New frets and the saddle in one setup
New frets change the playing surface. As a general rule, the action is then finalised at both ends of the string: at the nut and at the saddle.
The LF-20 project combined fret replacement with work on the nut, saddle and bridge pins. Considering these elements together gives the final setup a consistent starting point. If one of them is changed later, its effect on the setup should be checked again.
How to listen to sound samples
A recording lets you get to know how an instrument is presented, but it is also worth paying attention to how it was recorded and the settings used. A before-and-after comparison is most useful when the conditions are described and as similar as possible.
We treat our Thumb reel as a presentation of the finished guitar. We do not attribute everything you hear to any single replaced part. When choosing a solution for your own instrument, what matters most is still how you will use it and the agreed scope of the service.
Further reading
If you are interested in how a well-fitted nut is made, the StewMac material shows how the part is prepared, how the string spacing is laid out and how the slots are checked. Fishman's description of its AG series, in turn, illustrates why it matters to match the preamp to a passive piezo.