Patek Philippe Minute Repeater Advanced Research Fortissimo

Patek Philippe 5750P-001 has been hard at work redesigning the minute repeater, revealing its new fortissimo “ff” module in a new 15-piece limited edition platinum watch.

Patek’s Advanced Research series, which has been heading up the brand’s watchmaking innovation since 2005, set itself the task of reworking the fundamentals of the chiming watch to improve on the achievable volume and tone.

The team decided to create a module that “works like a mechanical loudspeaker,” enhancing the traditional hammer and gongs of a chiming watch. They developed an entirely new “mechanical sound amplifying system” consisting of a “flexibly suspended sound lever and an oscillating wafer made of transparent sapphire crystal.”

The steel lever – which is shaped like a tuning fork at one end – essentially serves as a stylus, transferring the sound to the wafer which acts as a sounding board.

And whereas a traditional minute repeater uses its case and sapphire crystals to resonate and transmit the sound of the hammer and gongs – meaning the case material has a strong influence on the sound – Patek’s new fortissimo “ff” system decouples the case from the module, propagating the sound through four openings at the cardinal points, with the sound waves exiting through a “narrow slot between the case back and the case band” with a dust filter protecting the movement.

The approach means that case material no longer has any bearing on the quality of the sound produced and that the watch is not water resistant but rather dust and moisture proof.

Patek states that the new module allows the sound of their new minute repeater to be heard at “a six-fold larger distance” and that the sound created also differs from that of traditional minute repeaters, with a longer resonant fade-out.

Patek is not the first manufacture to attempt to improve the sound output of striking watches. In recent years, Audemars Piguet developed its Supersonnerie, Chopard invented the L.U.C. Full Strike and Ulysse Nardin collaborated on the Hourstriker Phantom with Devialet.
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. Patek Philippe 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.
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. Patek Philippe 5750P-001 is audible at 60 m, a six-fold increase in volume.

Interestingly, Mr Stern also noted during his presentation that the ref. Patek Philippe 5750P-001 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.