Following the success of the Master Grande Tradition Gyrotourbillon Westminster Perpétuel at the Salon International de la Haute Horlogerie (SIHH), Jaeger-LeCoultre debuts a timepiece that once again brings new levels of excellence to its mastery of chiming watches.
New chime
Innovation in the domain of chiming watches has been one of the foundation stones of mechanical expertise at Jaeger-LeCoultre since 1895, when the company was awarded a patent for the world’s first silent strike regulator. In the 21st century, Jaeger-LeCoultre channelled its creativity in sonnerie watches towards producing the most energy-efficient and volume-optimised chime possible.
The Master Grande Tradition Répétition Minutes Perpétuelle represents the next generation of chime-related innovation at La Grande Maison. Its Calibre 950 unites the two apex values of chime quality that were previously thought to be incompatible — power and beauty.
The research and innovation team of Jaeger-LeCoultre have achieved this idealised chime by creating an entirely novel gong configuration. Instead of lying flat in overlapping coils like the most commonly seen minute repeater gongs, the gongs of the Master Grande Tradition Répétition Minutes Perpétuelle depart radically from convention by incorporating unprecedented height and space. Two gongs, welded together at their base, travel in the same direction around the periphery of the movement, making one near-complete tour before dramatically arching upwards, traversing the entire height of the movement. They then diverge and take a terminal semi-arc around the other side of the movement, stopping just before their ends meet.
By maximising the space occupied by the gongs, the Calibre 950 boosts its capacity for sound transmission. Further increasing this capacity is the proximity of the gongs to a larger proportion of the watch case, according to the acoustic principles that instinctively guide us where to position a relatively weak audio source in relation to an resonator.
Signature chime innovations of Jaeger-LeCoultre, such as the square gong cross-sections and the articulated “trebuchet” hammers, ensure that the gongs are struck with the greatest possible impact and the least interference from hammer recoil. These set the stage for the meticulously engineered acoustic profile of the Master Grande Tradition Répétition Minutes Perpétuelle chime.
The lower-pitched gong takes a helical path from gong heel to tip. Though irregular in shape, its unidirectional flow allows it to vibrate in a way that creates the harmonic overtones giving fullness and balance to bass notes.
The higher-pitched gong switches direction, effectively folding back on itself like the tines of a tuning fork. This configuration emphasises the fundamental vibration of the gong, producing a purer tone that imparts the clarity and brilliance prized in treble notes.
Automatic calibre
The ability of perpetual calendars to display the correct calendar information, taking into consideration the varying lengths of the months — even during leap years — provides everyday convenience for the wearer, especially when combined with an automatic winding system.
Traditional-style perpetual calendars are mostly hand-wound, as the prestige of a high complication generally demands that the finely finished movement should be fully visible for admiration. Automatic minute repeaters are even rarer, with occasional exceptions such as the Jaeger-LeCoultre Master Ultra Thin Minute Repeater Flying Tourbillon and the JaegerLeCoultre Rendez-Vous Ivy Minute Repeater.
The winding rotor of the calibre 950 is hidden within the movement, positioned between the perpetual calendar and minute repeater mechanisms, in order to a have full view on the mechanism at the back of the watch. The Master Grande Tradition Répétition Minutes Perpétuelle is thus continuously supplied with energy without the need to obscure a single finely finished component, whether chamfered, satin-finished, decorated with côtes de Genève, or any combination of the above.
Another feature of the watch that puts the needs of the wearer foremost is the intuitive Security zone that appears in a dial aperture near the axis of the hour and minute hands. This indication appears between the hours of 10pm and 1am, when adjusting the time or calendar is not advised due to the possibility of stressing or even damaging the movement.
Despite the multiple complications and the automatic winding system, the Master Grande Tradition Répétition Minutes Perpétuelle is highly compact, with a diameter of 43mm and a height of 13.72mm.
Design evolution
The Master Grande Tradition collection has always been a platform for high watchmaking at Jaeger-LeCoultre, emphasising classic design in order to let the sophisticated mechanisms take centre stage. A new case, comprising more than 80 separate hand-finished parts, was created for the Master Grande Tradition Répétition Minutes Perpétuelle. Particular attention was paid to the ergonomics of the case, from the deeply convex bezel and broad bevels on the lugs to the smoothly tapered minute repeater slide. Parts are alternately polished, satin-finished or sandblasted.
The Master Grande Tradition Répétition Minutes Perpétuelle comes in two dial variations, a neoclassical silver-grained dial and a deep blue translucent guilloche enamel dial that is produced by hand in the Atelier des Métiers Rares. Each model is a 30-piece limited edition.
A dial of solid white gold is first decorated with guillochage on century-old rose engines, each round of guilloché work repeated several times in order to achieve the correct depth of engraving. The perpetual calendar counters are then precision laser-welded onto the dial, before the remaining spaces are filled with translucent enamel in another multi-stage process. The enamel is then polished, resulting in the final dial of shimmering vitreous blue that changes in hue with the light and angle.
