Three new Audemars Piguet Royal Oak Chronograph 38 mm references in stainless steel and pink gold mark the debut of Calibre 6401, a new selfwinding chronograph movement developed to improve precision, reliability, and chronometric stability.
Designed specifically for the 38 mm Royal Oak Chronograph, the movement introduces a refined architecture and updated finishing while preserving the collection’s characteristic proportions.
These three models are also the first Royal Oak Chronographs of this size to feature a sapphire caseback, offering a clear view of the movement’s construction and decoration.
Developed entirely in-house over a five-year period, Calibre 6401 replaces the long-standing Calibre 2385, introduced in 1997 and a cornerstone of the Manufacture’s chronograph offering for nearly three decades.
Like its predecessor, Calibre 6401 is an integrated column-wheel chronograph equipped with a vertical clutch. Audemars Piguet has nevertheless simplified the architecture through a patented clutch mechanism, reducing the number of components and eliminating unnecessary play.
This technical refinement also translates into everyday use, with push-pieces requiring less pressure to activate the chronograph functions.
Operating at a frequency of 4 Hz (28,800 vibrations per hour), the movement delivers a power reserve of 55 hours and features an instantaneous date. The counter layout has been reworked to enhance legibility, with the minute counter now positioned at 9 o’clock and the hour counter at 3 o’clock.
The date aperture has also been repositioned for improved symmetry, sitting more centrally between the 4 o’clock and 5 o’clock hour markers.
Calibre 6401 will later be introduced into the Royal Oak Offshore collection, ensuring continuity across Audemars Piguet’s chronograph range.
Viewed through the sapphire caseback, the selfwinding movement reveals an openworked monobloc rotor and refined Haute Horlogerie finishing, including Côtes de Genève, alternating satin brushing, and polished chamfers.
Despite the technical updates, the watch retains the same proportions as its predecessor, with a case thickness of 11 mm.
The first of the three new references pairs the iconic “Bleu Nuit, Nuage 50” Grande Tapisserie dial with a stainless-steel case and bracelet, paying tribute to the original aesthetic codes of the Royal Oak (ref. 26450ST.OO.1356ST.01).
A second version in 18-carat pink gold features a dark grey dial with beige counters, introducing a more contemporary and warmer colour palette (ref. 26450OR.OO.1356OR.01).
The third reference combines an 18-carat pink gold case with a sand gold-toned dial, beige counters, and a diamond-set bezel (ref. 26450OR.ZZ.1356OR.01).
Prices start at €39,500 for the stainless steel version. audemarspiguet.com
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