How to produce a strong, clear sound from a wristwatch equipped with a minute repeater mechanism only too often continues to be a stumbling-block for many watchmakers. Scores, if not hundreds, of different solutions have been proposed in order to perceptibly improve the volume of sound produced by these timepieces, the principle of which first emerged at the turn of the 17th century. However, Girard-Perregaux purposely chose not to implement any of the previously existing solutions. None of these succeeds in both beguiling the ear by diffusing a powerful melody and delighting the eye by giving the wearer the opportunity to observe the components of the striking-mechanism during the course of their movements.
The Minute Repeater Tourbillon with Gold Bridges is a classic watch that displays on its front side not only a Tourbillon with Gold Bridges, but also the majority of the components that enable the minute repeater complication to produce a strong, clear sound.
The approach adopted here, which is as complex as it is original, perceptibly improves acoustic performance while offering observers the opportunity to appreciate the subtle mechanism of the minute repeater complication not only with their ears but also with their eyes. It should be noted that this is set in motion by sliding a bolt traditionally placed at 8 o'clock on the left-hand side of the case-band. Sliding this trigger-piece rewinds the spring contained in the minute repeater barrel. Once the maximum limit has been attained, this minute repeater winding mechanism releases the "on-off" control - an organ designed to prevent the striking-mechanism from starting if the winding of the trigger is not fully completed, thus preventing an incorrect acoustic indication of the time. Of all the minute repeater components, the only one that remains both invisible to the eye and almost undetectable by the ear is the complex organ known as the flywheel. Designed to regulate the hammers' striking speed, it operates on the case-back side so as to limit any sound emissions, however feeble they may be, and thus guarantees this watchmaking musical instrument's acoustic qualities.
In these enhanced conditions, the components of the striking-mechanism wind up and then release the hammers so as to strike with absolute consistency first the hours (in a low tone), then the quarter-hours (in a combination of high and low tones), and finally the minutes (in a high tone).
The decision to position the two gongs facing the inner side of the hour circle crafted in 18K gold, and to also place here the hammers (the shape of which is inspired by the Gold Bridges first patented in 1884) enables the acoustic wave, duly regulated at a carefully calibrated frequency, to reverberate harmoniously and not, as is only too often the case, to be confined by the excessive proximity of surfaces such as the skin. In addition to this, the relationship between the size of the case and that of the caliber has been carefully studied so as to offer the best possible volumetric arrangement, as in the case of musical string instruments. Even better, the inside of the case has been specially crTAnd since there is no room for false notes in a musical performance, the sapphire crystal case-back has also been crafted to give it the curvature found in the majority of musical instruments equipped with a sounding-box.
To house this exceptional mechanism, Girard-Perregaux has chosen a round case with a domed case-band prolonged by the slender lugs that are characteristic of models in the Haute Horlogerie collections. Its inclined bezel allows for a wide opening out over the movement and facilitates the spectacle of the minute repeater mechanism, of the hammers, gongs and Tourbillon. The emblematic arrow-shaped gold Girard-Perregaux Bridges and marking-plates identify the pedigree of this mechanism, with its finishes, crafted in accordance with the long traditions of the Manufacture. The caliber is also revealed on the case-back side with a third Gold Bridge and the Girard-Perregaux logo engraved on the main plate.
A black alligator strap with a pink gold triple folding clasp adds the finishing touch to this timepiece, a limited edition of 10 pieces.