Ulysse Nardin Blast Hourstriker

Presenting Ulysse Nardin Blast Hourstriker (with technical video interview)

Reading Time: 6 minutes

When we thought we have heard all about the hour striker and the room for innovations is close to an end, Ulysse Nardin launches a visual, technical but also auditive spectacular striking wristwatch – the Ulysse Nardin Blast Hourstriker. Created in collaboration with Devialet, the Blast Hourstriker uses ingenious sound tricks to deliver an astounding and powerful sound – a complete X factor experience.

From the oldest times, humanity used visual and auditive markers to give time measuring a notion. From the sound of the rooster in the morning in ancient times, time telling evolved in the middle ages, when striking hours started to be often met in the tower clocks (usually the appanage of the church clocks but also of the city halls bell towers). The evolution continued with domestic clocks that the wealthy of the time spent a small fortune for. Then the hand-held timepieces appeared that could chime the passing of each and every hour. The apogee was the development of the chiming wristwatches. Even if relatively quiet, the chiming wristwatches represent of revolution of miniaturisation and watchmaking expertise. Ulysse Nardin goes a step further and brings today the time in focus through sound – Ulysse Nardin Blast Hourstriker.

Ulysse Nardin Blast Hourstriker

It has been several years in the making but Ulysse Nardin has found a new way to make sound. Introducing the Blast Hourstriker, an innovative new striking watch that breaks barriers in sound technology. This art of marking the time with music has always been a part of Ulysse Nardin’s technical arsenal. It was revived in the 1980s, under the impetus of Rolf Schnyder and given a new lease of life in 2019 when the Swiss Manufacture collaborated with French audio technology company Devialet on the next level of watchmaking acoustics, which was launched in the Classico Hourstriker Phantom. This year Patrick Pruniaux, Ulysse Nardin’s CEO, has again made the choice to make sound central to the brand’s drive for more futuristic ways to reinterpret traditional watchmaking crafts.

When I’ve heard the news about the Ulysse Nardin Blast Hourstriker, it was mandatory to find out more about it. Jean-Christophe Sabatier, Chief Product Officer at manufacture Ulysse Nardin agreed to tell us more about the development, so we organised a friendly meeting to talk about all the technical details:

Ulysse Nardin Blast Hourstriker

The Blast Hourstriker is part of the recent Blast Collection, integrating technologies of the moment with innovative thinking. Ulysse Nardin collaborated with Devialet for a second time to produce not only a visually distinct, easy recognisable watch but also a loud hour and half hour chime.

Ulysse Nardin Blast Hourstriker
The main elements of the Ulysse Nardin Blast Hourstriker

The titanium and gold Blast case

We are already well familiarised with the Ulysse Nardin direction of Blast. Rose gold is used in combination with black DLC titanium for a powerful contrast on the 45mm case. The rose gold can be found on top and bottom, making a sandwich with the black DLC titanium. The gold components present an alternation of brushing and polishing that highlight, even more, the geometrical construction. Blast was designed to be seen and the alternation of finishes, surfaces and materials makes it well visible on the wrist.

Ulysse Nardin Blast Hourstriker
Ulysse Nardin Blast Hourstriker’s case plays with light

The Ulysse Nardin Blast Hourstriker present us with a rose gold crown with a deep negative engraving with grunge background. I am not really sure if sandblasting was used to create the background finish or a form of mechanical hammering.

Ulysse Nardin Blast Hourstriker
Visually appealing layered construction

On top, fixed in a black DLC titanium bezel, a box crystal sapphire accommodates the new complex mechanism’s need for space. The previous models of Blast have a flat crystal but the addition of the space-consuming complications required a more vertical increased arena. The result is a three-dimensional, multi depths spectacular view.

Ulysse Nardin Blast Hourstriker

Visuals and mechanics in details

At a first glimpse, the eyes run arround the watch’s face to discover all the elements nicely presented. Ulysse Nardin handled admirably the introduction of a visual striker with tourbillon, also keeping the proverbial “X”.

Ulysse Nardin Blast Hourstriker
Using the “X” as part of the design and as indexes

Besides the recognisable case, Ulysse Nardin integrated the “X” as part of the design combining beauty and functionality, the “X” serving as 1, 5, 7 and 11 hour’s indexes. Moreover, the entire dial and movement construction were based on the use of these Blast language elements.

Ulysse Nardin Blast Hourstriker
Flying tourbillon for the best chronometric properties

Ulysse Nardin Blast Hourstriker is powered by a flying tourbillon equipped with a variable-inertia balance wheel, a silicon hairspring, anchor and escape wheel. The chronometric properties of the tourbillon combined with the anti-magnetic properties of silicon will make this piece keep its chime in time regardless of the environmental magnetism or temperature.

Ulysse Nardin Blast Hourstriker
Chiming on top

Ulysse Nardin Blast Hourstriker present its striking mechanism on top. The entire movement was skeletonised and the chiming mechanism pushed to the front. Even the wire gong was pushed higher. Since the sound of the gong is usually muffled by the mechanism itself and case, Ulysse Nardin turned again to Devialet for help and expertise. Using the experience of the Phantom Hourstriker, the watch was fitted with new innovations to further improve the quality/power output ratio.

Ulysse Nardin Blast Hourstriker
The striking mechanism uses an acoustic chamber with a titanium membrane to deliver a powerful sound

When the striker is on, the mechanical ballet that makes the watch’s sound is visible on the hour and half-hour, but even its occasional activation is just as beautiful. By pressing the button located at 10 o’clock, the mechanism, driven by a specially dedicated barrel, is triggered. The hour rack and the inertia regulator start to turn; the hammers, visible in an opening made at 12 o’clock, hit the gong whose shape has been subtly worked to bypass the cage of the flying tourbillon.

Ulysse Nardin Blast Hourstriker
Note the round openings and the lever cut-out used to create the acoustic chamber responsible for the unusually loud sound

Finally, to ensure that the Blast Hourstriker’s striking mechanism acoustic performance is perfectly audible, the movement incorporates a Black DLC titanium membrane. Using black DLC makes the movement well visible due to its contrasting background. The membrane was developed in collaboration with Devialet – the French innovative audio technology company with whom Ulysse Nardin worked on its torsion lever used in 2019’s Classico Hourstriker Phantom (one of whose co-founders is a direct descendant of the Ulysse Nardin family).

Ulysse Nardin Blast Hourstriker
The caseback present the Blast collection “X” with cut-outs for the sound propagation

As in the Classico Hourstriker Phantom, the torsion lever connects the heel of the gong to the fine membrane. In this construction, it is pressed against a grid to prevent it from deforming in the event of extreme external pressure. This diaphragm is 3/10th of a millimetre thick and treated with black DLC, which offers a large deformation area, which, when under load, moves a large volume of air, which improves the audibility of the sound produced. Using the experience from the Phantom Hourstriker, a tunning screw was added for the best sound performance.

Ulysse Nardin Blast Hourstriker
The case back with integrated X and apertures for sound

The Blast line’s signature double X cut into the rose gold caseback, also ensures the security of this sensitive Devialet membrane, which, once in action, basically acts like a hi-fi speaker – releasing and amplifying the gong’s sound. Note the multitude of screws used: 6 screws are holding the caseback and 8 smaller ones are used for the acoustic chamber. The lower middle, round aperture is used for the final tuning of the acoustics.

Ulysse Nardin Blast Hourstriker

Final notes

Ulysse Nardin’s engineers and watchmakers developed the first in-house automatic striking movement, the UN-621 calibre:

  • 330 components automatic flying tourbillon offering 60 hours of power reserve and a manual wound chime
  • It brings a chiming mechanism on the dial side
  • Continues the development of an ingenious vibrating membrane developed with Devialet
  • Offers the possibility to learn and study in details the top chiming mechanism doubled by an excellent sound
  • Uses leading-edge technologies and concepts

Ulysse Nardin Blast Hourstriker integrates the brand’s latest generation of timepieces’s design language elements on the front and on the back of the watch, uses a manufacture calibre and delivers an extended Ulysse Nardin experience. Do I really need to repeat with other words how cool the Ulysse Nardin Blast Hourstriker is?!? Well done #weareulysse!

Ulysse Nardin Blast Hourstriker Technical Specifications


  • 6215-400/02 (Alligator)
  • 6215-400-3B/02 (Velvet)
  • 6215-400-3A/02 (Rubber)


  • UN-621 Manufacture Caliber
  • Automatic tourbillon
  • Automatic Flying Tourbillon for the movement /Manual-winding for the chiming
  • Features:
    • Flying tourbillon, hours, minutes
    • Skeleton movement
    • Hour striker (hours and half hours on demand)
    • Devialet sound amplification system
  • 330 components / 23 jewels
  • 4 Hz / 28,800 V/H
  • Power reserve: 60 hours


  • Rose gold 5N
  • Black DLC titanium
  • Glassbox Sapphire glass
  • Diameter: 45 mm
  • Case-back: Sapphire crystal
  • Water resistance: 30 m


  • Velvet, rubber, alligator


  • 91’100 EUR

Ulysse Nardin Blast Hourstriker Gallery

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