On October 30, 2025 I was among the first small group of watch journalists visiting the Valleé de Joux, more specifically the Blancpain farmhouse in Le Brassus, for the presentation of a new creation. Greeted by Marc A. Hayek and other senior representatives of Blancpain we were eager to find out more, but little did we know that we were about to see a milestone in watch making, artisan craft and innovation. This was not the presentation of a new watch, it was an exceptional horological experience. So let me now take you on the journey of exploring the Blancpain Grande Double Sonnerie reference 15GSQ for yourself.
.
Foreword
This article contains more than 130 photos, with slightly more than half provided by Blancpain, the remainder taken by me during the presentation. Most photos are shown in galleries, so you can click on the pictures to enlarge them and read the description. For the embedded videos you may have to adjust the settings to higher resolution for maximum quality when playing.
As part of the press material Blancpain have also shared a special edition of the Lettres du Brassus dedicated to the Grande Double Sonnerie, masterfully written by Jeffrey S. Kingston. This special LdB edition is way more comprehensive than what I can contribute and is linked at the end of this article for your reading pleasure.
.
Before we take a close look at the new creation it is important to understand the context in terms of Blancpain’s deeply rooted emphasis on and ability of making very complicated timepieces.
.
A heritage of Haute Horlogerie watchmaking
Blancpain was essential in reviving the world of mechanical watches following the Quartz crisis in the 1980s. The introduction of the six Masterpieces in and the at the time most complicated wristwatch in the world, named 1735, were an impressive proof that Blancpain was not only about the love for mechanical timepieces but also the full depth of crafting those in house.
.
The list of highly complicated Blancpain creations is long: the flying Tourbillon, Minute Repeaters ( also paired with automatons), the Carrousel, the Équation du Temps Marchante and the Traditional Chinese Calendar are impressive Grande Complications. In addition the Blancpain Metiers d‘Arts workshop showcases the highest level of creativity and masterful execution, often for bespoke unique pieces.
.
So we do know what Blancpain is capable of, or do we really?
A new frontier
It takes time to finalize the result of an idea, even more so when the idea evolves and expands over time. Getting to the desired results involves a lot of planning, adjusting, testing and refining. Tools and techniques have to be developed, parts have to be made and tested, new solutions for maybe unforeseen challenges have to be found. With a very ambitious goal in mind, the road to realization of the Blancpain Grande Double Sonnerie was a long one. The introduction to this amazing creation will be long as well… so I’ll better not overstress your patience and show some first impressions of the final timepiece:
.
It started in 2013 with Marc A. Hayek’s wish to create a Grande et Petite Sonnerie, something Blancpain has not built yet. Other than a Minute Repeater a Grande Sonnerie sounds the time in passage (without being specifically triggered through a slider or pusher) every hour and in addition the following quarter of an hour at 15, 30 and 45 minutes. A Petite Sonnerie usually sounds only full hours, sometimes also the quarters but without the preceding hour.
This mechanism in itself is considered one of, if not the highest level of complications, especially when you want to execute it with perfect clarity and rhythm in sound. So we can imagine that creating a perfectly working Blancpain Grande et Petite Sonnerie (of course including the Minute Repeater function) is quite a task… but what if you add not one but multiple challenges never been realized before?
Marc A. Hayek had some of those in mind: he wanted more than the two tones typical for Sonneries and Minute Repeaters, a high and a low note. Actually he envisioned the sound of time being a melody, for which 4 different tones/notes are required. Four different notes obviously need more than two hammers and more than two gongs, operating in perfect harmony.
.
Based on the task of realizing a true melody chime, the next layer of challenge was born: why not create a timepiece with two melodies to choose from? And, other than usual for Grande and Petite Sonneries, Marc A. Hayek wanted the mechanism to sound all 4 quarters on the full hour for maximum experience.
This already starts to sound very difficult to realize in a wristwatch, but there’s more to add to the task. A perpetual calendar shall be part of the timepiece, and not as a typical module but fully integrated. The Grande Double Sonnerie has to be as transparent as possible for the beholder to fully appreciate and enjoy it. The challenge of finding the space for this complication in an already highly complex movement cannot be overestimated.
And since we are in the process of adding complexity, Marc A. Hayek wanted the famous Flying Tourbillon to be part of the watch, too.
.
To conclude defining the scope of this new frontier all the above had to be realized in a wearable wristwatch and in a secure way, so that damage through accidental misuse is avoided. No question this movement has to be finished to the highest level for a masterpiece of that magnitude.
Suddenly a timeframe of roughly a decade between idea and finalization sounds quite reasonable, doesn’t it? Next let us take a look how the goal was accomplished, no doubt with many prototypes and different evolution stages to be mastered.
.
New solutions
During the presentation in Le Brassus we were invited into a „secret laboratory“ in the farmhouse, where the watchmakers involved in the development shared insights into various challenges and solutions step by step. It was evident to us visitors how much skill, knowledge, creativity and passion went into this endeavor.
.
The first step of realization had to be the Grande et Petite Sonnerie and the melody. The starting point was the famous Westminster chime and the notes required for that, Mi/Sol/Fa/Si.
.
To achieve best possible audibility, clarity and richness the hammers and sounding rings (or gongs) have to be carefully chosen in terms of material, profile and length. This is a very elaborate process during which the watchmakers at Blancpain discovered 4 hammers striking on three gongs (with one gong being struck in two places for two different notes) to be the ideal solution.
To give you an idea of how detailed the process of fine adjustment is: all gongs have to be at the correct length for meeting the desired frequency, and this length is adjusted to micron (!) level by hand.
.
In addition you want the strikes of the gongs meeting the correct tempo. Ideally without disturbing sounds from the Grande Sonnerie typical regulator (or governor) which is meant even out adverse influence from varying torque. So Blancpain opted for a completely silent and very precise magnetic regulator which maintains a constant rate despite the change in torque from the unwinding barrel.
.
The gongs are crafted from gold, as transmission of sound is better when the watch case and the gongs are made of the same material. To further enhance audibility and clarity, Blancpain developed a gold membrane, attached to the crystal and hidden under the bezel. This membrane in connection with glass and bezel emphasizes the desired lower and filters the less desirable higher frequencies to improve the sound performance.
.
Now to the centerpiece of playing a melody, the „pièce des quarts“ or quarter hour element. With its fine teeth it corresponds with the „levée“, meeting its tip, bringing it to rotation and activating the attached hammer. For this mechanism to work perfectly and meet the tempo tolerance of one tenth of a second (!), the watchmaker has to fine adjust the teeth of the pièce des quarts and the levée, again on micron level.
.
Double that effort since we are talking about not one but two melodies. This means the mechanism features two pièces des quarts, firmly attached to each other. That requires the 4 levées, each attached to one of the four hammers, to have arms at two different levels, corresponding with the two piéces des quarts.
.
The selection of the melody happens through a button in the case flank at 8 o‘clock, the second pusher at 10 is for activation of the Minute Repeater function.
.
Now it’s time to talk about the second melody. We have found out that the first is the Westminster chime, and the second melody has been created by a long time friend of Marc A. Hayek, rock musician and KISS drummer Eric Singer.
.
The task of creating a melody may sound rather straightforward, but actually it was the contrary. Eric Singer had to use the same notes and the same tempo defined by the Westminster chime, and he could not use the same note twice in direct sequence. He succeeded in creating 10 options, of which Marc A. Hayek and himself chose one to be the second melody, called Blancpain.
….
To give a Grande Double Sonnerie an adequate environment, Blancpain has created a sound chamber in the Le Brassus farmhouse. It was exactly here when during the visit we heard and saw the Grande Double Sonnerie as a completed timepiece for the first time.
.
Now let us listen to both melodies in comparison, first the Westminster, then the Blancpain chime.
.
We now move on to the perpetual calendar. Since a module construction, even in a skeletonized execution, was not an option, the watchmakers started more or less from scratch.
I mentioned before that the perpetual calendar had to comply with the open architecture of the movement and find its space, on top of that the calendar indications for day, date, month and leap year had to respect the desired transparency of the Sonnerie and the Tourbillon. Given this environment, it was decided to have a retrograde date indication with the Perpetual Calendar.
.
For quite some years now, Blancpain watches feature „secure movements“ to avoid potential damage to (not only) calendar functions through accidental misuse, e.g. setting the calendar at the wrong time (during its change process) or if time was adjusted backwards. It was considered absolutely necessary to have the same protection in this new construction, too.
It also had to utilize another patented Blancpain specialty, the under-lug-correctors. These are an easy, comfortable and aesthetically superior way to set the calendar. With a retrograde date and an entirely new compact perpetual calendar construction embedded on the right side of the movement, this system had to be practically re-designed.
.
Also the Flying Tourbillon as one of Blancpain’s signature complications received changes. The frequency has been increased from 3Hz to 4Hz and it now features a silicon spiral resulting in improved chronometric performance.
.
So is there anything left to do? Sure there is: the timepiece has to not only function perfectly when assembled, but also after years when used (hopefully frequently) by its future owner. Wearability does not only refer to the size, shape and weight of a timepiece, it also means every component must stand the test of time. With the help of special machines aging is simulated and tested until you have the desired results.
.
To summarize what it meant to find all these new solutions, here’s an impressive number: for the development of the Grande Double Sonnerie Blancpain has developed 21 patents, of which 13 are embedded in the movement of this timepiece.
.
Finishing
So far we have looked at the technical aspects of the Grande Double Sonnerie, now we pay attention to the aesthetic virtues, primarily the artisan movement decoration.
By now it is evident that we talk about a very important timepiece, the most complicated Blancpain to date. Obviously this level of sophistication has to extend to the movement finishing and the craft skills behind it.
.
Blancpain traditionally finishes not only those movement parts visible to the beholder of the cased up watch, but all of them, front and back. This means that some decorations are only to be seen by the watchmaker during assembly or service, but nonetheless this is an essential part of Blancpain’s approach to fine watchmaking.
For a piece like the Grande Double Sonnerie this approach is taken to the maximum. Responsible for the finishing of all parts is the dedicated workshop in the Le Brassus farmhouse with its experienced and skillful artists.
.
With the movement of the Grande Double Sonnerie we talk about anglage, perlage, Côte de Geneve, mirror and fine polishing, fine brushing as the main techniques, all by hand with specially designed tools. One mistake and (in the best case) the artisan starts anew or (in the worst case) the part is destroyed.
.
I want to show only one example at length, since Jeff Kingston elaborates much more on the topic in the Lettres du Brassus Special Edition, which is linked at the end of this article.
So let‘s talk about anglage and interior angles. Like the mainplate, the bridges of the Grande Double Sonnerie are made from red gold, offering more brilliance when finished. One example is the open worked bridge for the perpetual calendar with 42 sharp interior angles, carved by hand with the visual aid of microscopes.
.
Upon inspection of earlier prototypes, Marc A. Hayek decided against the usual 45 degree bevels. Instead the Grande Double Sonnerie received a 30 degree beveling, which is less steep and more exposed to light reflections and therefore visible to the beholder.
.
The polishing of the bevels and interior angles is done in multiple steps by progressively finer polishing compounds affixed to various wood tools, with the final step using a 1 micron polishing powder, which feels perfectly smooth to the human fingertip.
.
Now contemplate this: the movement of the Grande Double Sonnerie features 135 interior angles, all carved and finished by hand to the highest degree.
.
The finished parts the leave the Atelier for the assembly of the movement, which is done not once but twice. When everything is perfect it will be encased and a finalized Grande Double Sonnerie is born.
.
The finalized watch
Two specimen of the Grande Double Sonnerie were present at the presentation, reference 15GSQ 1513 55B in white gold and reference 15GSQ 3613 55B in red gold. Both are suggestions how the watch looks since each customer can specify his preferences in terms of case material and other aesthetic choices like the dial. In the end each Grande Double Sonnerie may very well be a piece unique.
.
The case measures 47mm in diameter at a height of 14.5mm. The lug to lug is 54.6mm and the lug width 23mm. The dial is made from 5N gold, in these two examples featuring applied Roman numerals. On the left side we find the 5N gold ring for the retrograde date display.
.
The movement caliber 15GSQ has 1053 parts including 67 jewels, is manually wound with a power reserve of 96 hours and operating at 4Hz. The striking power reserve in Grande Sonnerie mode is 12 hours.
.
The annual production of the Grande Double Sonnerie is limited to two pieces. Only two watchmakers at Blancpain are dedicated to this timepiece, each working on his own piece until finalized. The personal signature of the watchmaker will be engraved on the backside of a gold plaque fitted to the movement, the visible side of it shows the engraving of the Blancpain signature. The new owner receives the watch in a special presentation box, which acts as a natural soundboard by amplifying the chime.
.
Conclusions and thoughts
I was lucky enough to hold the 1980s Blancpain 1735 in my hands during a manufacture visit in 2018. Now I had the honor to be among the first few outside people to see and hear the Blancpain Grande Double Sonnerie, learn about its creation and even meet the watchmakers and artisans behind it. What more could you possibly ask for?
The Grande Double Sonnerie is not only Haute Horlogerie at its finest, I think it actually is a piece of art. It took 12 years from the first idea to the finalized watch, one can only imagine how proud all involved individuals must rightfully be.
.
From conceptualization through tools and parts design, prototype production, testing, refinement and finishing… everything has happened internally creating this exceptional timepiece. So in essence this watch tells us everything about Blancpain, their spirit, passion, dedication and capabilities. This is at every level a Manufacture de Haute Horlogerie.
To conclude our little journey, what could be more appropriate than looking at and listening to the Grande Double Sonnerie chiming all four quarters and therefore the full Blancpain melody:
.
This visit to Le Brassus will stay very vital in my memory, it was no less than the highlight of my personal horological journey so far. I can’t thank Blancpain enough for this experience.
As promised above, here’s the link to the Lettres du Brassus Special Edition with comprehensive articles on every aspect written by Jeffrey S. Kingston. I am sure you will enjoy it massively.
You also find the Grande Double Sonnerie here on the Blancpain website and the official press release here.
I hope you enjoyed this introduction to this new horological milestone. As mentioned above, many photos are credit Blancpain, the first three melody videos were done by myself using the provided official material, the final video is also credit Blancpain.
Cheers
Henrik