The Excalibur Diabolus in Machina is equipped with a minute repeater mechanism, a flying tourbillon and an automatic double micro-rotor system. In addition, this watch also has a disc indicator for repeating the melody and an 'all or nothing' safety device. The minute repeater, invented to read the time at night before the advent of electric light, is considered one of the most challenging watchmaking complications. In particular, it is the only one that requires the watchmaker to make so many manual adjustments throughout the assembly process in order to achieve the ideal tune. It is also the only one that requires genuine musical talent on the part of its creator, who tunes it with great precision, almost as if it were a musical instrument. The melody of the Excalibur Diabolus in Machina is activated at the push of a button: the information on each cam is mechanically read by the minute repeater's pivot-probe system, which transmits it to the racks which, in turn, allow the hammers to strike the gongs. The latter emit a low tone for the hours, a high tone for the minutes and two tones for the quarter-hours. Consisting of three tones or six semitones, the tritone sound - also known as the triad or waning fifth - has an astonishing rhythm for the listener, as it does not respect musical conventions. This particular dissonance was called 'the devil's chord' or 'diabolus in music' and was absolutely forbidden in medieval religious compositions. Roger Dubuis chose the tritone sound as the chime for the minute repeater of his Diabolus in Machina to give his own unprecedented interpretation of this particular complication. Among the various technical advances that characterise the Excalibur Diabolus in Machina is the repeating disc indicator at 11 o'clock. Activating the minute repeater triggers the rotation of this disc, which crosses one of the Roman numerals on the dial and bears the inscriptions Hours, Quarters and Minutes. Operation is further simplified by another function indicator showing whether the watch is in the 'manual winding' or 'time setting' position. In addition to enhancing the design of the timepiece with its ingenious integration at 4 o'clock, it plays a useful safety role by preventing potential damage that could be caused by adjusting the watch when the minute repeater is in operation. The watch, powered by the calibre RD 107 (mechanical self-winding, 452 parts, 54 jewels, 21,600 vibrations per hour, 72-hour power reserve), which has been awarded the Geneva Seal of Approval), sports an imposing 45 mm case in pink gold or DLC titanium and is fitted with a calfskin strap.
