The sound of a classical or flamenco guitar is the result of an extremely delicate physical system: the string tension, the neck vibration, the transmission of that vibration through the heel into the body, the resonance of the soundboard, the response of the back and sides. Everything is connected. Everything communicates. And when someone tells me they want to separate the neck from the body of their instrument, the inevitable question is: can that be done without breaking the chain?
The short answer is yes. But it deserves a long explanation, because a short answer is not enough to convince a serious guitarist to trust their instrument to a process they do not fully understand. So let us go to the long explanation.
What people think will happen (and what actually happens)
Before getting into the physics and the lutherie, it is useful to lay out the most common preconceptions about detachable necks and contrast them with the reality of the Pullaway system:
- The sound loses body or projection
- The guitar goes out of tune constantly with assembly and disassembly
- The joint vibrates or produces strange resonances
- Over time the assembly will loosen and the sound will worsen
- The neck shifts and affects the action
- Heat or humidity loosen the joint
- The sound is identical to that of a one-piece guitar
- Tuning stabilises within minutes after assembly
- The solid-wood joint produces no parasitic resonances
- The dovetail assembly does not wear with normal use
- The action remains stable between disassemblies
- The wood responds just like any glued joint in lutherie
That said: the fact that this is what happens with the Pullaway system does not mean it happens with every detachable neck system. The result depends entirely on how the assembly is designed and executed. And that is precisely the difference that matters.
The physics behind the sound: why the joint matters so much
To understand why the Pullaway system does not affect the sound, one must first understand how sound travels in a classical guitar.
How vibration travels in a guitar
When you pluck a string, the vibration travels from the string to the saddle, from there to the bridge, from the bridge to the soundboard, and from the soundboard to the entire body (back and sides), which acts as a resonance chamber and acoustic amplifier.
The neck, in this system, plays a dual role: on the one hand, it maintains the geometry of the instrument under string tension. On the other, it transmits part of the vibration to the body through the heel, the block of wood that connects both pieces. This transmission has particular influence on the harmonics and sustain of the instrument.
For that transmission to be complete and without losses, the joint between the neck and the body must be solid, precise, and without gaps. Any micro-gap between the two pieces acts as a vibration damper, reducing the transfer of acoustic energy and thus impoverishing the sound.
This is exactly the problem that the Pullaway system solves through its solid-wood dovetail assembly, hand-fitted with millimetre precision to eliminate any gap between the neck and the body.
The technical conclusion is clear: what determines whether a detachable neck affects the sound is not the fact that it is detachable, but the quality and precision of the assembly. A perfectly fitted joint in solid wood transmits vibration exactly like a permanently glued joint. A poorly fitted joint, with play or inadequate materials, can affect the sound.
Why the Pullaway system uses only wood (and why that makes all the difference)
One of the most important design decisions of the Pullaway system — and, in my view, the most sound from an acoustic standpoint — is the complete absence of metal elements in the assembly. No screws, no bolts, no steel inserts. Only hand-worked wood.
This is not aesthetic whim or marketing. It has a concrete acoustic reason: metal and wood have completely different vibration transmission properties. When you introduce a metal element into the acoustic transmission chain of a wooden guitar, you also introduce a discontinuity in that chain. Metal can dampen certain frequencies, create its own resonances, or simply interrupt the energy transfer in a way that wood does not.
Detachable neck systems that use screws or metal inserts — common in mass-produced electric guitars, and in some entry-level acoustics — have this problem. They work well for what they are designed for, but they are not comparable in acoustic terms to a purely wood joint.
A perfectly fitted solid-wood joint transmits vibration the way silence transmits sound: without interfering.
The Pullaway system uses an artisanal variant of the dovetail — a geometric wood-on-wood joint, without adhesives and without metal — that has proven over centuries in traditional cabinetmaking to be one of the most solid and durable joints that exist. Adapted to guitar lutherie, with the precision fit that the acoustics of the instrument require, it is the system that most closely approximates a permanent joint without being one.
Traditional guitar vs. Pullaway guitar: acoustic comparison
To make it easy to visualise, here is a comparison of the main acoustic parameters between a traditionally built classical guitar and a guitar with the Pullaway system:
| Acoustic parameter | Traditional guitar | Pullaway system |
|---|---|---|
| Neck–body vibration transmission | Permanent glued joint | Solid-wood dovetail — Equivalent |
| Presence of metal elements in the assembly | None (Spanish construction) | None — Identical |
| Projection and volume | 100% based on the woods | 100% based on the woods — No difference |
| Sustain and harmonic response | Depends on construction | Identical when the fit is perfect — No loss |
| Tuning stability | Permanent | Stabilises within minutes — Very slight adjustment |
| Action stability | Permanent | Permanent between disassemblies — No difference |
| Parasitic resonances | None (if well built) | None (if the fit is precise) — Equivalent |
| Assembly durability | Permanent (glued) | Thousands of cycles without wear — Lifetime guarantee |
The only aspect in which there is a minimal difference compared to a conventional guitar is tuning stability immediately after assembly. The strings may need a few minutes to settle after assembly, especially if there have been temperature or humidity changes during transport. It is comparable to what happens with any guitar that has been in its case for a while: a few minutes and it is ready.
Concert musicians who use the Pullaway system confirm this: they assemble the guitar, tune it once, and are ready to play. That is all there is to it.
Tuning: the other great fear
Along with sound, tuning is the second most common concern. And it is perfectly understandable: a guitarist stepping onto the stage cannot afford to waste time tuning or face surprises in the middle of a concert.
What happens in practice, with the Pullaway system, is the following:
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You assemble the neck — the guitar is almost in tune Thanks to the precision of the assembly, the neck always sits in exactly the same position. The geometry of the instrument does not change, and the strings maintain tension very close to the last tuning.
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You tune normally — in one or two minutes As with any guitar that has travelled or been stored, the strings need a small tuning adjustment. It is no different from what you would do when taking your guitar out of its case after a flight.
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The guitar is ready — and the tuning is stable Once tuned after assembly, the guitar holds its tuning exactly like a conventional guitar. There is no tendency to go out of tune because of the detachable neck. The joint is so solid that no movement is possible.
Quim Ramos, a Cirque du Soleil musician who changes country every two months, uses the Pullaway system on every trip. Christopher Avilez used it throughout an entire tour of Mexico. Neither has reported tuning stability problems. Coming from musicians who perform under real stage conditions, that is the most reliable proof there is.
What guitarists who have already tried it say
Technical explanations are useful, but in the end what convinces a guitarist most is other guitarists. These are the words of some of the musicians who take the Pullaway system to their concerts:
The most remarkable thing is that this detachable system in no way compromises the tonal quality of the instrument, nor does it present any issues regarding tuning. I recommend it without reservations, convinced that its qualities will satisfy the highest demands of any guitarist.
— Jaume Torrent, guitarist and academician of the Royal Academy of Fine Arts of Sant JordiThe Pullaway detachable system demonstrated impeccable stability before, during and after my tour of Mexico. Tuning, precision and the stability of the instrument were maintained at 100% at all times.
— Christopher Avilez, classical guitar concert performerAn incredible and very practical system. I was impressed that, as well as being very easy to assemble, it does not alter the tuning or the sound of the guitar.
— Jurandir Da Silva, guitaristThe Pullaway system is a necessary advance for guitarists who travel and do not want to spend a fortune on extra seats. Totally impressed: we applied it to one of my guitars, which I take everywhere. I carry it in a backpack!
— Paco Seco, concert guitaristThe luthier's honesty: is there any case where there is a difference?
I promised at the outset an honest answer, and an honest answer also includes the less comfortable nuances.
The Pullaway system, properly executed, does not affect the sound. That is true. But "properly executed" is an indispensable condition. If the assembly is not perfectly fitted — if there is even a tenth of a millimetre of play, if the contact surfaces are not perfectly flat, if the geometry does not exactly reproduce the original neck position — then there can indeed be acoustic consequences.
That is why every installation of the Pullaway system is adjusted individually, by hand, for each guitar. It is not a serial process. There is no standard piece that installs in ten minutes. The time the process takes is precisely the time it requires to do it properly.
That is also why I do not accept conversions on guitars that do not meet the necessary structural conditions. A guitar with a weakened heel, with low-density woods, or with a construction that does not offer the minimum rigidity cannot guarantee the same result as a well-built luthier guitar. In those cases, I prefer to say no rather than deliver work for which I cannot stand behind with a lifetime guarantee.
The factor that most determines the acoustic result of a Pullaway guitar is not the system itself: it is the quality of the original guitar. An instrument with well-selected solid woods, built with artisanal criteria, responds to the Pullaway system with its full potential. A low-quality instrument with the Pullaway system is still a low-quality instrument. The system does not make anything worse, but it does not perform miracles either.
Want to hear it for yourself?
On the NRG Luthier YouTube channel you can watch demonstrations of the Pullaway system in action — with the guitar's sound as the centrepiece. And if you have specific questions about your instrument, write to me directly.
Watch video demonstrations →The final answer: no, if it is done properly
A detachable neck affects the sound if the assembly is not precise, if there are inadequate materials in the joint, if there is play or discontinuity in the vibration transmission chain. That is true of any detachable neck system, just as it is true that a poorly executed glued joint also affects the sound of a conventional guitar.
The Pullaway system, with its solid-wood dovetail assembly individually adjusted for each instrument, solves those problems with the same logic that has guided traditional lutherie for centuries: precision in the work, respect for the properties of the wood, and no compromise on quality.
The result is a guitar that you can disassemble, put in a carry-on bag, fly to any destination in the world, assemble on arrival and play. Without anyone who hears you — or yourself while playing — noticing any difference.
That is the honest answer from a luthier.