Alto Watches Caliber A01

ALTO Caliber A01

Alto Watches Caliber A01

Brand ALTO
Caliber Number A01
Cercle des Horlogers
Movement Type Automatic, self-winding mechanical, micro-rotor
37.5mm x 33.15mm
Jewel Count
Beat Rate
28,800 vph, 4 Hz
Lift Angle
Power Reserve
48 hours
Rotor Style
Anti-Shock Device
Hand Count 3
Functions Central hours; central minutes; central sweeping “countdown” seconds
Microblasted grade 5 titanium mainplate
Country of Manufacture Switzerland, Swiss made (La Chaux-de-Fonds, Neuchâtel)
Known Models

The ALTO caliber A01 is a micro-rotor automatic watch movement with 32 jewels and a power reserve of up to 48 hours.

This calibre is found in the brand’s debut piece: ALTO ART 01 First Edition. It is a limited edition with only 25 pieces available.

ALTO first published images of the ART 01 on April 29, 2024 on their official Instagram account, as well as a video (see below) on their official YouTube channel.

In ALTO’s own words:

“The micro-rotor movement, custom designed for the ART 01, showcases an architecture that’s as much a piece of art as it is a feat of engineering. This commitment to both form and function exemplifies ALTO’s ethos of melding art thoroughly with watchmaking, setting a new benchmark in the world of horology.” –@altowatch on Instagram, April 29, 2024

Alto Cal A01

Noteworthy Complication:

Aside from its unique bridge design, the cal. A01 features a counterclockwise seconds hand aka anti-clockwise seconds. The hours and minutes advance in normal clockwise fashion, while the seconds hand sweeps in reverse.

While it’s interesting to see all of the hands moving backwards to tell the time in reverse order, counterclockwise watches and clocks aren’t always practical or easy to read. The mixture of rotational direction allows for normal time-telling via the hour and minute hand, making the ART 01 legible with a special novelty “trick” to show off.

The moment the seconds hand sweeps past the 12 in reverse direction, while the minutes hand advances forward to mark the start of a new hour, will likely put a smile on the wearers face each time.

Alto Caliber A01 Hands On

Manufacturered by Cercle des Horlogers for ALTO Watch:

While the brand refers to the A01 as an in-house movement in their marketing copy (at least in the translated version), it is technically a manufacture movement, produced by Le Cercle des Horologers.

The ART 01 has its own in-house movement, a micro-rotor self-winding caliber with “counter-clockwise” hours, minutes and seconds function.” –Source (translated from French, the only language provided on ALTO’s site at this time)

And also this:

“The A01 caliber was imagined by designer Barth Nussbaumer, and entirely developed by the Cercle des Horlogers manufacture in Neuchâtel.” -Source same as above

This “Circle of Watchmakers” is the movement manufacturing house behind some other haute offerings such as the Trilobe X-Centric, and the basis of various Speake Marin calibers – some sharing similar architecture, materials, and the micro-rotor winding system.

While not exactly “in-house” as Caliber Corner would define it, the A01 is exclusive to ALTO and stands out with its unique modifications including the square form-factor, skeletonized design of the bridges, and the counterclockwise sweeping seconds.

Alto Caliber A01 Prototype


From the ALTO “Entourage” page, here are some of the folks that were involved with the ART 01 project.

Replacement Price:

The ALTO caliber A01 obviously does not have a replacement price for the movement since the caliber is exclusive to ALTO. The retail price for an ALTO ART 01 with the cal. A01 is CHF 18,450 (about $20,300 USD).

Video: Meet the ART 01

Watches with this movement:

Additional Resources:

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