Monochrome Watches
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Armin Strom Minute Repeater Resonance – Step 2 in the Masterpiece Collection

Armin Strom celebrates its 10th anniversary with a spectacular minute repeater regulated by resonant oscillators.

| By Xavier Markl | 4 min read |
Armin Strom Minute Repeater Resonance Masterpiece 2

If you are a recurring reader of MONOCHROME or simply into independent watchmaking, you are probably familiar with Armin Strom and their innovative Resonance concept. Launched with the Mirrored Force Resonance in 2016, later used to regulate a dual-time watch, the brand’s first “Masterpiece”, the second chapter in this ultra-complex series of watches has just been presented… And here, resonance is used on two levels, as you’ll see below. Meet the impressive Armin Strom Minute Repeater Resonance.

Armin Strom Minute Repeater Resonance Masterpiece 2

The concept of Resonance

Resonance is one of the most outstanding phenomena in all physics: two oscillating bodies in proximity influence each other and eventually synchronize. Back in the 17th century, Christian Huygens observed the phenomenon with two of his recently invented pendulums (read our introductory article on the Armin Strom Mirrored Force Resonance here). Since then, resonance has fascinated many watchmakers but few worked on this concept, and even fewer mastered it. In 2016, Armin Strom propelled the application of resonance in watchmaking to an unprecedented level with their caliber ARF15.

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Armin Strom Minute Repeater Resonance Masterpiece 2

The novel idea of Armin Strom has been to connect the two oscillators by a spring. The two balance wheels therefore get coupled by the tiny vibrations in the spring, getting them to synchronize faster. Finding a concurrent rhythm, they continuously average out errors for maximum accuracy. Armin Strom states again inprecision of about 15% to 20%.

Armin Strom Minute Repeater Resonance Masterpiece 2

Full Resonance in Chronometry… and Sound

Beyond this odd physic phenomenon, resonance is also a concept used in sound to describe its quality as deep, full and reverberating. From there came the idea of creating a minute repeater (which strikes the time) regulated by resonant oscillators. Embarking on this ambitious project, Claude Greisler (co-founder and technical director of Armin Strom) contacted long-time friend Alain Schiesser from Le Cercle des Horlogers. The two men used to work together at Claret in the early 2000s. Le Cercle des Horlogers is one of the industry rising movement-makers, the motorist of several independent watchmakers and a company working behind the scene for several big names in the industry. Furthermore, Le Cercle des Horlogers is specialized in striking watches.

Armin Strom Minute Repeater Resonance Masterpiece 2

The development of the Armin Strom Minute Repeater Resonance is thus a joint-venture, each party contributing its expertise. The same goes for the manufacturing and assembly of the watch and its movement. For instance, if the vast majority of the movement components are manufactured at Armin Strom, the gongs are crafted by Le Cercle des Horlogers. The result of this work in tandem is rather impressive, to say the least!

Armin Strom Minute Repeater Resonance Masterpiece 2

The first thing to catch your eye with the Armin Strom Minute Repeater Resonance is its architectural, open-worked design, focusing all the attention on depth, contrast and movement. The hand-wound calibre ARR18 creates a compelling animated mechanical sculpture. The upper part of the watch features the chiming mechanism: the black-polished hammers strike on a pair of three-dimensionally curved gongs framing the off-centered hours and minutes indication on a transparent sapphire dial. The lower part shows the twin oscillators beating in sympathy. When activating the chime, the spectacle of the hammers, governor and oscillators is truly captivating, as you can see in the short video below:

Comprising no fewer than 408 parts, the movement of the Armin Strom Minute Repeater Resonance is in fact made of two vertically stacked movements with two independent mainsprings in one barrel. The twin-balance wheels operate at 3.5Hz and the power reserve is of 96 hours (or 4 days). Turning the watch over, the exhibition case back offers an unimpeded view on the barrel and the intricate striking mechanism.

Armin Strom Minute Repeater Resonance Masterpiece 2

A specially developed security system maximizes ease-of-use by protecting the minute repeater from accidental damage by blocking operation during time-setting and winding. As you would expect for such a marvel of mechanical engineering, the finishing is top-notch with superbly polished surfaces contrasting on dark grey ruthenium-coated bridges and plates, and tremblage for the barrel and balance bridges.

Measuring 47.7mm in diameter, this Armin Strom Minute Repeater Resonance is fashioned out of grade 5 titanium for optimal sound propagation and wearing comfort. The chime is enhanced by attaching the gongs directly to the case. It is water resistant to 30m and the chime is nonetheless loud and clear.

Armin Strom Minute Repeater Resonance Masterpiece 2

Price and Availability

The Armin Strom Minute Repeater Resonance is worn on a dark grey alligator strap secured by a double folding buckle. A limited edition of 10 pieces only, this watch retails for CHF 380,000. For more information, please visit

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