The Patek Philippe Advanced Research 5750 Minute Repeater

Founded in 2005, Patek Philippe‘s “Advanced Research” department aims at improving mechanical movements and bringing innovative solutions in the fields of materials (silicon, for instance) and technologies for watchmaking. This goes for the introduction of Silinvar (2005), the Spiromax balance spring (2006), the Pulsomax escapement (2008), the Oscillomax ensemble (2011), and a further optimized version of the Spiromax balance spring (2017). In 2017, the brand will look at something different, and that is a compliant mechanism for the dual-time function, in an Aquanaut. Today, following a year with already a grande sonnerie watch, the brand continues its researches in the field of chiming watch, with major improvements on the minute repeating watch, with the new Patek Philippe Advanced Research 5750 Minute Repeater. 

The technical solutions

The goal of the Advanced Research department is to bring new solutions in order to innovate, or in the present case to improve existing mechanisms. For this new introduction, the team in charge has been working on the chiming watch, a speciality of the brand that counts multiple repeating watches in its collection. The base for this watch is existing, as the movement takes on the classic Calibre R 27 that the brand introduced in 1989. The idea with this new Advanced Research 5750 Minute Repeater was “to amplify the volume of the time strike in a purely mechanical manner while preserving the excellent acoustic quality as well as the smallest possible dimensions.” Keeping the base of the existing calibre, the watchmakers of Patek created a new module that works like a mechanical loudspeaker.

Usually, amplification of the sound does rely on a flexible diaphragm which like the skin of a drum is attached along its periphery. But here, Patek Philippe created something different… Instead of a membrane, the system for which Patek Philippe registered three patents has an oscillating wafer made of synthetic sapphire with a thickness of 0.2 mm. Thanks to its angular motion, this rigid and freely movable wafer provides clearly better sound propagation for the confined volume of a wristwatch. Plus, this allows to retain the sapphire caseback and thus the possibility to admire the movement.

To achieve sound transmission from the gongs of the minute repeater to the sapphire-glass oscillating wafer, the engineers developed a system with a steel sound lever that is attached in the middle of the oscillating wafer. “The other end of this sound lever that resembles a tuning fork features a flexible attachment with a thickness of 0.08 mm. When the hammers strike the gongs, their oscillations are transmitted to the sound lever which in a first phase amplifies them and transmits them to the rigid oscillating wafer where they are further amplified. The angular motion of the oscillating wafer excites the air layers above and beneath the sapphire glass, producing a noticeably louder sound,” explains the brand about this so-called fortissimo “ff” amplifier module.

With the Patek Philippe Advanced Research 5750 Minute Repeater, the brand also worked on the propagation of the sound, in addition to amplifying it. Classically in a repeater watch, the sound of the hammer striking the gongs is propagated through the entire watch – on all sides of the case, on the back and through the crystals. It’s why the material chosen for the case is of great importance – and titanium and steel are known to provide better sound than gold or platinum, due to lower density. Specifically, the latter is the most challenging for a minute repeater. In the minute repeater with the fortissimo module, an insulation rim made of a high-tech composite material acoustically uncouples the amplifier from the movement. The sound is first routed to the sound lever and then to the oscillating wafer and subsequently propagated through four openings at 12, 3, 6, and 9 o’clock in a titanium ring. The sound waves exit through a narrow slot between the caseback and the caseband – there’s a dust filter to protect the movement. Thus, the case material has no more influence on the sound of the watch. So, even if this watch would later come in yellow, white or rose gold, its sound will be identical.

Some work has also been done by the Patek Philippe Advanced Research team on the loudness of the sound, but also on the quality, richness and musicality of the minute repeater. For instance, the length of the strike has been increased in order for the gongs to fade somewhat longer. Some evolutions have been done on materials too. Classically, hammers are made of steel but in this Advanced Research 5750 Minute Repeater, they are made of platinum – a patented solution that improves the quality of the strike. Also, a minirotor in platinum replaces the eccentrically recessed minirotor in 22K gold. Thanks to the greater material density, it delivers the same winding power with a thinner design.

The Patek Philippe 5750P Minute Repeater

The new Calibre R 27 PS and its four patents are housed in a watch that shows novel design elements, yet a typical Patek shape and feel. A limited edition of only 15 pieces, the 5750P is a classic model, with a 40mm diameter, a shape that recalls previous repeater models from the brand – specifically the 5178 minute repeater with cathedral gongs – with its rounded casebands and stepped lugs. It’s a fairly thin watch, with a height of 11.1mm. And if these elements are classic, the dial is far bolder but no less impressive.

The design of the dial is a 5-part element with “an openworked motif inspired by the spoked wheels of vintage automobiles” that stands out against a black background with a snailed pattern. Intricate and complex, the same motif is repeated on the small seconds, which is a rotating disc with a small marker that serves as a hand – which creates a dynamic effect on the watch. Time is indicated by flat Dauphine hands in white gold and applied kite-type hour markers in blackened white gold.

The back reveals the in-house Calibre R 27 PS, with its classic (understand not cathedral) gongs and, of course right in the middle, the sound lever in the shape of a tuning fork that carries the transparent oscillating wafer of the fortissimo amplifier system. This 3Hz, automatic movement is equipped with all of the brand’s technologies, including the Gyromax balance spring in Silinvar launched in 2006. All the parts are finely decorated, with Geneva stripes, bevels and a platinum micro-rotor with a ray pattern in the style of the dial, created with a laser-based light-absorbing surface texturing technique that allows certain segments to appear black.

Availability & Price

The Patek Philippe Advanced Research 5750 Minute Repeater is worn on a bold, shiny orange alligator strap with contrasting black stitching, closed by a platinum fold-over clasp. It is a limited edition of 15 pieces only, priced at CHF 590,000 – obviously not cheap for a minute repeater, but far more accessible than a Tiffany-blue Nautilus 5711… and far more complex!

For more details, please visit patek.com.