Jaeger LeCoultre : Master Réserve de Marche Ultra Thin

Regardless of its degree of complexity or the price range where it will fit, each new model presented by Jaeger-LeCoultre is eagerly anticipated by connoisseurs as a new milestone among the broad range of models on offer in this second decade of the 21st century.

While the brand from the Vallée de Joux does not systematically set record prices in auction rooms, it is nonetheless acknowledged by professionals and collectors alike as one of the most solid pillars of Fine Watchmaking. Thanks to its exemplary communication strategy and above all to its history and the infallible quality of its products, Jaeger-LeCoultre has become a brand with a heart that with disconcerting ease manages to combine huge popular success with the unanimous respect shown by the greatest specalists.

The fantastic qualitative unity shown by the Manufacture in its management, communication, the aesthetic of its watches, the intelligence of its innovations, and of course the excellence of its movements, have forged its success – and will thus lead us to be a little more fussy than usual in this Test Bench. The object of this study is the Master Réserve de Marche Ultra Thin presented at the SIHH 2012.



Exterior elements

The now almost 20-year old Master Control collection has established a quality label as well as a classic style that is timeless yet progressive. The case dimensions of this ultra-thin power-reserve seem to hark back to a bygone age when watches could still count off the hours with elegance and discretion, and succeeded in finding their place beneath a shirt sleeve. Such is the first impression felt when actually picking up this timepiece. A soft sense of nostalgia for the heyday of Fine Watchmaking as our parents or even our grandparents knew it, combined with a modern watch that is reassuring in terms of the pleasure to be experienced from wearing it over the coming decades. Once again, its successful design lies more in the proportions of the case rather than in its specific dimensions. 39 mm in diameter and 10 mm thick : measurements that might seem outdated today, since modern watches claiming to be ultra-thin often feature large diameters. The size chosen by Jaeger-LeCoultre makes it an extremely elegant and yet radiantly elegant watch. The pink gold version entrusted to us for the Testing Bench features a lacquered ivory-toned dial enhanced by the collection’s signature hour-markers and dauphine hands. It single-handedly embodies one of Jaeger-LeCoultre’s most remarkable qualities. It is extremely simple, classical and not particularly original in technical or aesthetic terms, and yet whether one is a newcomer to the field or a seasoned specialist, it exudes a sense of quality and success that is immediately and intuitively perceptible.

The strap also radiates quality in the clean-cut edges of its full-grain alligator leather and its supple feel that invites admiration and appreciation. Since this is an ultra-thin model, it is quite naturally fitted with a pin buckle.




You don’t change a winning team, and we would certainly have held it against Jaeger-LeCoultre if were to have done so, since this Manufacture-made movement doubtless represents one of the finest automatic calibres ever produced. So yes, it is well known and has already been used by Jaeger-LeCoultre. It has also appeared in watches by some of the other most prestigious names in Fine Watchmaking – a fact that in itself eloquently confirms the performances of this exceptional calibre. The legendary Calibre 889 served as a basis for this Calibre 938, which appeared right from the early days of this collection. Although very thin, this movement was not referred to at that time as ultra-thin, since the Jaeger-LeCoultre watchmakers were capable of creating and producing automatic watches that were distinctly thinner. The dimensions might even be described as almost standard, except that in this instance there is also an automatic winding system and a module displaying the power reserve, small seconds and a pointer-type date indication. The decoration has remained as standard (Côtes de Genève) at it is perfect. There would be no point in going into further details, since everything essential has already been said about this movement (including in this column).




Our tests seem pretty lightweight compared with those that each Master Control watch has to endure before emerging from the factory. This 1000-hour control conducted with the movement fully cased-up makes it probably one of the finest quality labels to date. We nonetheless verified the performances of this calibre. Firstly, the automatic winding mechanism, which is undoubtedly one of the best ever made (at least in this writer’s opinion). The reduction is perfect so as to ensure that the spring is wound almost effortlessly and as quickly as possible. The 22-carat gold oscillating weight segment and the magnificent reverser enabling winding in both direction definitely play a role. A mere few hours of wear in office-type conditions is enough to make the power-reserve hand display a fully charged 42-hour autonomy level.

The rates achieved could serve as a benchmark for the various precision timing authorities. The amplitudes measured after 0 and 24 hours remained within a range between 268° (vertical position after 24 hours) and 288° (horizontal position 0 hours). The rate results were even more stupendous and quite simply unprecedented in the appraisals described in this column to date. Taking the measurements as a whole, the maximum variation was a mere 4 seconds, and each of the measurements was within the range of +2 to +6 seconds a day. Although we were expecting excellent chronometric precision, yours truly was tempted to doubt his measuring equipment, and from the second day onward, all measurements were backed by another timing machine – leading to the same results. If you’re looking for a watch with a movement that is beautiful, accurate and reliable, the Master Control 1000 Hours label is a genuine guarantee !




As was mentioned in the introduction, when it comes to the best, one is naturally more demanding. Over the ten or so days spent with this watch, every single detail was tirelessly examined. Rarely had a watch as a whole achieved such excellent results and induced such a feeling. So in fact the only slight disappointment is to note that Jaeger-LeCoultre is presenting as a new release a watch that was launched almost 20 years ago in the same collection and which has been revamped – but this is common practice that should not cause offence, even though this miniature marvel is in fact a true classic.

Cet horloger chevronné analyse une montre qu'il porte pendant toute une semaine et en livre son bilan technique et esthétique

Review overview