Minute repeater technique is the peak in wristwatch complex functions. And that is the reason behind a minute repeater that sounds like a weak cricket in late autumn may ask for more than 500,000RMB. Those large complications just aim to combine minute repeater with other complex functions and have given birth to minute repeater perpetual calendar, minute repeater split second and the Petek Philippe Ref.3939H- minute repeater tourbillon which is really impressive. However I never saw a factory that combined minute repeater with hour jumping structure till 2007 Basel Fair-Audemars Piguet made a bold try and developed the Cal. 2907 manual wound minute repeat hour jumping movement:
This movement has a surprising diameter of 37mm. You know, even IWC who is the grandfather of big watches has very few bare movements of such large size. Maybe the numeral is not enough to make you feel how big it is. Here comes a comparison: Another Audemars Piguet movement that has the same functions as Cal.2907 except minute repeater is only 22.6mm at diameter. That is to say Cal.2907 is longer by 50% ! Large movement, certainly, offers bright and clear reading for the hour jumping window. In addition, large movement can contain bigger barrel, which provides more development space for power reserve.
The Cal. 2907 is 7.6mm thick, very reasonable. Compared with those 10mm+ movements on the market, this thickness is much more suitable and comfortable to wear. It smartly uses bearing of 35 stones and beats at 21,600 VPH. It is true that it may look more attractive if upgrade the frequency to 28,800 VPH but it will definitely influence the precision. As we all know, the minute repeater will consume extra barrel power when working. Then high frequency will not take any advantage in time travel because more power consumption does influence the time travel of the whole watch. Sure enough, the medium frequency design brings 72 hour power reserve to Cal. 2907.
The minute repeater part adopts double-spring and double-hammer design which ensures sonorous sounds. The design of the splints is very classic. It is believed to the the fruit of mechanical CAD and brain aesthetic sense. It totally adopts string upper splints. What is more, from barrel, balance to escapement plate, no even one straight line is adopted. Big polished screws are used to fixed upper plates. The counter bores of stone bearing also receives refined polished treatment. As for the design of balance , Audemars Piguet, for the first time, adopt double-arm eight weight GYROMAX balance which of similar feeling as Petek Philippe.
The diameter of whole watch reaches 43mm. Thanks to large movement, the dial is considerably nice designed: the small seconds subdial is perfectly located with a reasonable size that meets aesthetic requirements. The improved willow-leaf-shape hand keeps the track of time while the hour jumping window under 12 o’clock position tells hours. Minute hand and Arabic numerals are made of blued steel. Everything comes so perfect. The only problem maybe the price.
