Saving the best for last, Patek Philippe has just announced the Ref. 6301P-001 Grande Sonnerie. Powered by a movement derived from that in the Grandmaster Chime ref. 6300G uber-complication, the new Grande Sonnerie is impressively complicated – which is why Patek Philippe set up a dedicated workshop for its assembly – yet surprisingly thin.

Unlike the Grandmaster Chime that was a multi-complication, the ref. 6301P is a focused mechanical masterpiece: a grande and petite sonnerie, striking the time en passant, or as it passes. But it is also a carillon, striking on three pairs of hammers and gongs, instead of the usual two.

All its mechanical accomplishment is dressed in classical style, with an aesthetic reminiscent of the ref. 5370P split-seconds chronograph – a black enamel dial with Breguet numerals and a recessed case band.

Initial thoughts

With a movement derived from the Calibre 300 found in the Grandmaster Chime, the Grande Sonnerie is almost as large, a necessity due to the size of the movement. At 44.8 mm in diameter, the Grande Sonnerie is a large watch, but it is surprisingly thin at just 12 mm high, which is perhaps unsurprising given Patek Philippe’s traditional inclination towards thin watches.

Unlike the brand’s other extra-large grand complications, like the Grandmaster Chime or Sky Moon Tourbillon, the Grande Sonnerie has a more restrained, traditional design. Though imposing, it looks reasonably elegant due to the pared-back styling and subtle details.

Fans of the brand’s mid-20th century style will no doubt appreciate the design of the Grande Sonnerie, which manages to include many of the elements favoured in vintage Patek Philippe watches, like Breguet numerals. The luminous paint on the hands is curious, but not intrusive, although I am certain some clients will be able to specify hands without “lume”.

The hour and minute hands are luminous

But the crucial bit of the Grande Sonnerie is what’s inside, and here Patek Philippe has done well. Although not a developed-from-scratch calibre, the GS 36-750 PS IRM is still a modern movement, with all of the conveniences and innovations expected, including a silicon hairspring. While that might be controversial with traditionally-minded collectors, the engineers at Patek Philippe clearly believe in the material. And more importantly, come what may, Patek Philippe will be around to repair or replace everything in the calibre, which addresses the widely-held concern about the longevity of silicon parts.

At the same time, the movement appears to be finely decorated in a more traditional style than the average Patek Philippe complication. Most of the bridges feature sharp, acute angles on their outlines – the balance cock has two for instance – which require the polishing of the bevels to be done by hand. While certainly not done to the same artisanal standard as Philippe Dufour, the decoration on this movement appears to be as good as the best of the mainstream brands like Chopard or Vacheron Constantin.

Notably, the new Grande Sonnerie is the second such complication launched this year. In fact, Audemars Piguet unveiled its Code 11.59 Grande Sonnerie just a month ago. While the Code 11.59 costs a third less than the ref. 6301P, it is less accomplished technically. The Code 11.59 is equipped with a movement that’s based on a calibre from the 1990s, and a good part of its technical innovation lies in the patented, double-backed Supersonnerie watch case.

Priced at a bit over one million Swiss francs, Patek Philippe’s Grande Sonnerie is expensive in nominal terms, but par for the course relative to what such watches cost. It’s in the same ballpark as the grande sonnerie wristwatches made by Greubel Forsey and Vacheron Constantin (which share the same base movement), which makes it a reasonable proposition as such things go.

GS 36-750 PS IRM

A watch that was first mooted in 2007, the Grande Sonnerie is powered by the GS 36-750 PS IRM, a movement derived from the Calibre 300 GS AL 36‑750 QIS FUS IRM of the Grandmaster Chime uber-complication.

Impressively complicated, the movement is composed of 703 parts. It is clearly a 21st century construction, incorporating three patents – including for an isolator that disengages the strikework in silent mode – as well as silicon, which is used for the hairspring as well as the jumping seconds mechanism.

Visually, the movement is also clearly modern. Instead of a cock, it has a full bridge for the balance wheel – which is more stable. And the twin barrels sit under a large barrel bridge, going without the old-school exposed winding clicks typically found on grande sonnerie pocket watches.

But the fundamental set up of the movement is familiar: twin barrels, each with two mainsprings – the pair closer to the balance wheel driving the going train for the time, while the other two are for the striking mechanism.

The back of the movement is identical to Calibre 300 of the Grandmaster Chime, but it does away with the calendar mechanism (as the Grandmaster Chime has the perpetual calendar display on the case back.

Similarly, the dial layout echoes that of the Grandmaster Chime, with both power reserve indicators in the same positions, as does the pusher co-axial with the crown to activate the minute repeater.

But while the Grandmaster Chime has a moon phase display at six, the Grande Sonnerie has a deadbeat seconds driven by a silicon wheel and lever, a feature taken from the Chiming Jump Hour “175th Anniversary” ref. 5275P, which had jumping hours, minutes, and seconds.

Reminiscent of the dial on the ref. 5370P split-seconds chronograph, the Grand Sonnerie dial is enamel – a disc of 18k white gold covered in black vitreous enamel. All of the hour markers are Breguet numerals that are also 18k white gold, as are the hands.

And the platinum case is also similar to that of the ref. 5370P, having the same distinctive brushed, recessed case band with round platinum inserts at the end of each lug.

The slide at six o’clock selects the striking mode, either full- or quarter-strike, or silent

Key Facts and Price

Patek Philippe Grande Sonnerie
Ref. 6301P-001

Diameter: 44.8 mm
Height: 12 mm
Material: Platinum
Crystal: Sapphire
Water resistance: Moisture- and dust-resistant; not water resistant
Dial: Black enamel

Movement: GS 36-750 PS IRM
Functions: Hours, minutes, jumping seconds, power reserve indicators for both strikework and timekeeping barrels, grande and petite sonnerie carillon on three pairs gongs and hammers
Winding: Manual wind
Frequency:  25,200 beats per hour (3.5 Hz)
Power reserve: 72 hours for time, 24 hours for strikework

Strap: Alligator leather with folding clasp

Availability: From Patek Philippe Salons and authorised retailers
Price: 1.15 million Swiss francs including taxes, and 1.06 million francs without

For more information, visit Patek.com.