This will be the third occasion I have gone to the well of Jaeger-LeCoultre to cover watches for DreamChrono, and while it might appear to be showing bias, this is not the case. JLC rather forced my hand with the release of the Jaeger-LeCoultre Master Ultra-Thin Minute Repeater Flying Tourbillon. It’s the first the maison has produced such a piece and it creates a new record for being the slimmest watch to contain a tourbillon a minute repeater and at the same time to be powered by an automatic movement. Of many fine pieces that will be on display at SIHH 2014 this month, this could prove to be the shapely, sweet chiming show stealer. It certainly has all the right credentials.

This is the eleventh timepiece to be produced in what Jaeger-LeCoultre call their Hybris Mechanica collection. Its simple appearance belies its innate complexity. The elegant case is a compact 7.9mm thick with a sensible 41mm diameter. The dial is clean and white, only a cut away at 6 o’clock gives a glimpse of the tourbillon. Impeccably contained within the case is a 471 component in-house movement which powers both the tourbillon and a minute repeater; two of the most important complications known to watchmakers, and both of which JLC is admirably equipped to show off their skill and expertise.

The ultra-trim flying tourbillon has no bridge and no cage to obstruct the view. This required the development of a new larger than usual balance spring which has had the added bonus of actually improving precision and accuracy. Most balance wheels feature a hairspring placed under the oscillating wheel but JLC have placed the hairspring on top. While there is no genuine advantage to this, it does display to those in the know what a very clever and visually appealing flying tourbillon it is.

The minute repeater is made of white gold apparently for extra resonance; like the tourbillon it is ultra-thin, which required a complete reworking and rethinking of how things are normally done.

First of all, JLC did away with quarter hour chimes. If no quarter hours are being struck, there would usually be a pause between the chimes for the hours and the chimes for the single minutes. However with this minute repeater it compensates for the lack of quarter hour chimes so that there is much less of a gap throughout the chiming sequence.

Keen observers of minute repeaters will also be searching for a traditional long slide along the caseband, but Hybris Mechanica Eleven is an ultra slim watch this was considered too clunky, so instead there is a push button neatly recessed into the case at 10 o’clock. It’s easy to control too at the musical cleft positioned at 8 o’clock there is a smaller than normal slide which can be activated.

JLC has also incorporated their innovation for the hammers that they first introduced some years ago. The hammers made not of steel but sapphire mounted to the back crystal. Classical in appearance, there are two of these gongs and they are said to produce a stronger clarity of chime.

Just for extra ingenious fun, because SIHH is really all about showing off to the cognoscenti of the watch world, JLC opted not for a manual wind movement but an automatic, and they fitted the watch with a platinum rotor to enable smooth wrist propelled automatic winding. The rotor can be observed spinning through the cut-away slots on the dial.

There is so much reinvention and rethinking happening within the slim confines of this supremely elegant high-end dress watch, that six of the eight patents it has for its various mechanisms are new to this piece.

Unpretentious and simple in its appearance, under the hood this slim, sober timepiece is a trailblazing technological triumph which no doubt caused many a sleepless night its wonders to achieve. The chances of getting your hands on one are, like the watch itself, ultra slim. The Master Ultra-Thin Minute Repeater Flying Tourbillon is limited to just 75 pieces.

Jaeger-LeCoultre Master Ultra Thin Minute Repeater Flying Tourbillon
Technicals Specifications

Movement:

•  Mechanical automatic movement, Jaeger-LeCoultre Calibre 362, crafted, assembled and decorated by hand
• 45-hour power reserve
• 21,600 vibrations per hour
• 471 parts
• 4.8 mm thick
• 33.3 mm in diameter

Dial:

• Silver-toned, grained
• Traditional baton-type (transferred)
• Hands: Dauphine type

Functions:

• Hours, minutes
• Minute repeater equipped with silent-timelapse reduction function
• Flying tourbillon with flying balance-wheel
• Automatic winding via a peripheral oscillating weight

Case:

• 18-carat extra-white gold
• 7.9 mm thick
• 41 mm in diameter
• Polished lugs, entirely polished caseband and bezel
• Water resistance: 3 bar

Strap: Black high-end Jaeger-LeCoultre alligator leather, white gold high-end pin buckle
Reference: 131 35 20, 75-piece limited series

More resources about this watch available on Watch Insider, and Hodinkee.