Patek Philippe Introduces the “Advanced Research” Minute Repeater Ref. 5750P

Amplified by the patented "fortissimo" mechanism.

Just days after the inaugural Nautilus ref. 5711/1A Tiffany & Co. 170th Anniversary sold for just over US$6.5 million, Patek Philippe has announced a wristwatch at the other end of the watchmaking spectrum.

The latest in a series of watches focused on experimental new technologies, the “Advanced Research” Minute Repeater ref. 5750P-001 is the ultimate Patek Philippe minute repeater in terms of acoustics. Equipped with a patented amplification device named ‘fortissimo “ff”‘, the ref. 5750P strikes chimes that are so loud they are audible 60 m away according to Patek Philippe.

Initial thoughts

The ref. 5750P is interesting both mechanically and aesthetically. The R 27 PS movement certainly lives up to the “Advanced Research” label with its amplification mechanism, while the design is practically radical, at least in terms of Patek Philippe grand complications.

While the “fortissimo” device relies on a few familiar principles, including a crystal soundboard and perforated case back, it is still novel enough to make it interesting. While other watchmakers have built repeating movements based on the same concepts, including Audemars Piguet with its Supersonnerie, Patek Philippe has done it in a classical fashion with an impressively thin movement that is very much typical of the brand.

Visually, the ref. 5750P is radically different from any Patek Philippe repeater. Even the most contemporary of the brand’s striking watches are conventionally classical in style.

This divergence in design is good thing; I like this design. While the case is clearly vintage-inspired with its Vichet-esque lugs, the open-worked dial is different, interesting, and original. Granted legibility is poor since the hands are lost in the spoked pattern, but that’s arguably moot in a striking watch.

Given the ref. 5750P is limited to just 15 watches, it doesn’t indicate a new direction for the brand’s house style, though it would be a positive development to see more stylistic boldness in other new models.

Perhaps most intriguing is the fact that during the introductory presentation, Patek Philippe president Thierry Stern noted that the ref. 5750P is “50%” of what he considers the perfect repeater, which implies there’s a lot more to come. Given that the last all-new repeating calibre introduced by Patek Philippe was some decades ago, it sounds like there are great things in store at Patek Philippe.


The first four Advanced Research models were all about silicon for the escapement and oscillator – which culminated in the ref. 5550P perpetual calendar – and then followed by the complaint mechanism for the dual time zone mechanism of the Aquanaut ref. 5650G.

Now Patek Philippe has turned to an entirely different aspect of watchmaking for the sixth instalment in the Advanced Research series. Based on the self-winding minute repeater movement introduced in 1989, the R 27 PS in the ref. 5750P boasts four patents relating to the amplification mechanism for the repeater.

According to Patek Philippe, the “fortissimo” mechanism was inspired by a gramophone, resulting in modifications and additions to the traditional repeater construction. But the basics of the repeater mechanism were also upgraded for optimal sound, including the pace of the striking. The hours, quarters, and minutes have been adjusted so they are struck slightly further apart. As a result, the chiming sequence for “11:59” takes about three second longer than usual.

The movement still relies on hammers and gongs, but the hammers are platinum instead of hardened steel as is the norm. According to Philippe Barat, the brand’s head of technical development, several materials were experimented with, but platinum gongs offered the longest-resonating chimes, perhaps because of the metal’s high density.

The set up of the gongs is key to the “fortissimo” mechanism. They are mounted to a base that incorporates a transmission lever. The lever in turn is secured to a clear sapphire disc positioned right above the movement, while the base is attached to a titanium ring that nestles against the inside of the case back. Put simply, the chiming bits are mounted to the ring, while the movement itself is secured to the case middle.

The case of the ref. 5750P is further isolated from the striking mechanism with a polymer isolation ring, basically a soft, plastic-like buffer, that encircles the movement, preventing stray vibrations from reaching the striking mechanism.

When the gongs vibrate, the sound waves generated are transmitted via the arm to the sapphire disc, which Patek Philippe calls an “oscillating wafer”. The disc amplifies the sound, which transmitted further outwards thanks to four apertures in the titanium ring.

And there is a narrow gap between the case back and case middle – with a silicon-mesh filter to protect the movement from dust and moisture – allowing the sound to leave the case. Like conventional minute repeaters, the ref. 5750P has no water-proofing gasket around the minute repeater slide, rendering the case not water resistance.

According to Patek Philippe, the maximum distance at which a conventional repeating wristwatch can be heard is 10 m. With the “fortissimo” mechanism, the ref. 5750P is audible at 60 m, a six-fold increase in volume.

Interestingly, Mr Stern also noted during his presentation that the ref. 5750P sounds best when it is activated on the wrist, as the chimes can be transmitted out of the case and onto the wrist, which further amplifies the sound.

R 27 PS

Beyond the acoustic innovations, the calibre was tweaked to accommodate the “fortissimo” mechanism. The rotor as well as repeater bridge directly under the transmission arm were made thinner in order to accommodate the mechanism. With the addition of the mechanism, the movement is 6.05 mm, one millimetre taller than the standard R 27 PS.

Because the rotor has been reduced in height, it is made of platinum, which is denser than gold, the alloy used for the rotor of the standard movement. And the movement is decorated with a laser-etched motif that echoes the pattern of the open-worked dial – a laser precisely scorches the surface of the rotor to create black segments against the concentric brushing.

The under-dial view of the movement with the strikework visible on the left

The calibre with the amplification mechanism removed

And some stylistic novelty

The dial of the ref. 5750P is inspired by the wheels of classic cars of the 1920s and 1930s, which were usually distinguished by their wire spokes in an interlaced pattern. Made of 18k gold, the dial is comprised of several components to create the open-worked motif.

Coated in black nickel plating, the dial base has a concentric pattern. Above it are the open-worked spokes that are framed by a brushed chapter ring.

The hour markers are black-coated white gold in a “kite” shape. And the hands are a modern take on the dauphine shape, accented with glossy black lacquer printed lengthwise.

Most unusual, at least in Patek Philippe terms, is the seconds wheel. In a first for the brand, an open-worked wheel replaces the seconds hand. The wheel echoes the dial motif and incorporates a tiny pointer on its rim to indicate the passing seconds.

The only evidently classical element of the design is the case. Though it is seemingly identical to the case of the ref. 5178G minute repeater, it is actually entirely different.

For one, the construction is new, since changes were required to accommodate the thicker movement and “fortissimo” mechanism. As a result, the case is 11.1 mm high, thicker than the typical Patek Philippe repeater, but not by much (the ref. 5178G is 10.53 mm).

At the same time, because the case is platinum, the case middle is a one-piece construction that was milled in its entirety, before being refined and polished by hand – a process that takes six hours. In contrast, the white gold case of the ref. 5178G has individually soldered lugs, which is not viable for platinum according to Patek Philippe.

The brand indicates that platinum was chosen as the case material to emphasise the point that the “fortissimo” mechanism functions entirely independently of the case. Despite being substantially denser than gold, making it a less ideal choice for ordinary striking watches, platinum has no impact on the chimes of the ref. 5750P since the sound is transmitted from movement to oscillating wafer and out of the case.

Key facts and price

Patek Philippe “Advanced Research” Minute Repeater
Ref. 5750P-001

Diameter: 40 mm
Height: 11.1 mm
Material: Platinum
Crystal: Sapphire
Water resistance: Dust and moisture resistant (not water resistant)

Movement: R 27 PS
Functions: Hours, minutes, seconds, and minute repeater
Frequency: 21,600 beats per hour (3 Hz)
Winding: Automatic
Power reserve: 43-48 hours

Strap: Orange alligator with folding clasp

Limited edition: 15 pieces
 At both retailers and boutiques
Price: CHF590,000

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