Audemars Piguet Tourbillon Automatique 25643BA

Audemars Piguet Ultra-Thin 25643BA World's First Automatic Tourbillon 18k YG

Launched in 1986 just as the Quartz Crisis was beginning to peak and Swiss watchmakers were continuing to go defunct, the Audemars Piguet Tourbillon Automatique ref. 25643BA was debuted as the world’s first automatic tourbillon in an effort from AP to continue pushing high horology. Powered by the ultra-thin cal. 2870 movement, which uses the ref. 25643BA’s caseback as its movement baseplate – as evidenced by the visible presence of six rubies on the caseback, the ref. 25643BA stands an incredibly thin 5.5mm tall – impressive even by today’s standards for an automatic tourbillon. Offered in a rounded rectangular 18kt yellow gold case, the ref. 25643BA features a stunning golden champagne dial whereby its tourbillon aperture, placed at 11 o’clock, serves as the central point of its display with an Art-Deco-inspired sunray pattern radiating across the rest of the dial. Featuring a blued steel hammer weight with applied ‘AP’ initials that swings back and forth like a pendulum in a crescent-shaped aperture at 6 o’clock, the ref. 25643BA is a stunning expression of how unique 1980s high-end watchmaking could be outside of the scope of quartz watches. Brand : Audemars Piguet Dimensions : 28.5mm x 32.5 mm x 5.5mm Model : Tourbillon Automatique Movement : Automatic cal. 2870 Reference : 25643BA Bracelet : Leather strap Year : Circa late 1980s Condition : Excellent Material : 18kt yellow gold Included : Watch only Dial Color : Champagne THE DIAL Serving as the epicenter of the ref. 25643BA's dial, the Tourbillon Automatique's champagne dial features art-deco-inspired rays of sunshine that shine down from its tourbillon cage at 11 o'clock. THE CONSTRUCTION Using its caseback as the baseplate of its movement, as evidenced by the six visible rubies set into the caseback, the ref. 25643BA's automatic cal. 2870 allows the watch to stand just 5.5mm tall, an incredible feat for an automatic tourbillon, even by today's standards. TIMING MACHINE READOUT This reading was taken (crown down) with a ONEOF Accuracy Boutique Edition timing machine at time of cataloging. It is provided as a courtesy only, and shall not be construed as a warranty or guarantee of any kind. Please refer to our terms and conditions of sale for more information.