MB&F – three colourful new LM Perpetual editions

Key Highlights

• Three new LM Perpetual Chromatic editions, each limited to 8 pieces — among the rarest Legacy Machine Perpetuals ever made
• Bezels set with 48 baguette-cut gemstones: red rubies (Mozambique), blue sapphires (Madagascar & Sri Lanka), purple sapphires (Madagascar)
• Two editions in 18k white gold; one in 18k red gold — with PVD-treated hands matched to each gemstone or case colour
• All stones set by hand by STG Création in Geneva, without increasing the 44 mm case diameter
• Powered by the same 581-component fully integrated calibre designed by Stephen McDonnell, winner of the GPHG Best Calendar Watch Prize in 2016

Colour as Conviction

Since its debut in 2015, the Legacy Machine Perpetual has occupied a singular position in independent horology — a perpetual calendar architecture so thoroughly reconceived that it won the Grand Prix d’Horlogerie de Genève’s Best Calendar Watch award the following year. For 2026, MB&F adds chromatic conviction to that technical identity. The three new LM Perpetual Chromatic editions introduce coloured gemstone bezels that do not merely ornament the watch; they reframe its entire visual proposition.

Each bezel carries 48 baguette-cut stones set by hand by STG Création, MB&F‘s long-term Geneva partner. The ruby edition — 1.95 carats of Mozambican red stones — is mounted on an 18k red gold case, its hands finished in 5N PVD to echo the warmth of the gold. The two sapphire editions occupy 18k white gold cases: the blue variant uses stones from Madagascar and Sri Lanka (1.95 cts), while the purple uses Madagascan sapphires (1.93 cts), each with correspondingly tinted PVD hands. The colour coding is total and considered, not decorative afterthought.

Production Scarcity

Eight pieces per edition. The figure is not a marketing construct — it reflects the hand-labour intensity of the setting process and MB&F’s consistent preference for small series over broad distribution. These are, by production volume, the rarest LM Perpetuals the atelier has released.

The Mechanical Processor — Still the Point

The gemstone bezels are the new element; the movement beneath them is the permanent one. Stephen McDonnell’s fully integrated 581-component calibre dispenses with the traditional grand levier in favour of a mechanical processor — a stack of superimposed disks that defaults to a 28-day month and adds the correct number of days for each calendar month rather than fast-forwarding past redundant ones. Date-jumping, the chronic liability of conventional perpetual calendars, is structurally eliminated. So is the risk of damaging the mechanism during adjustment: the quickset pushers automatically deactivate as the date changes.

The movement also features a dedicated pusher to set the leap year directly — bypassing the laborious process of scrolling through up to 47 months required by traditional architectures. The 72-hour power reserve is delivered by double mainspring barrels; the balance oscillates at 18,000 bph and is visible suspended above the dial, connected to the escapement on the caseback via what MB&F describes as likely the world’s longest balance staff.

Dial Architecture

Legibility across six indications — hours, minutes, day, date, month, retrograde leap year, and power reserve — is achieved through skeletonised subdials that appear to float with no visible support. This is technically possible only because the absence of the grand levier frees the centre of the movement for the balance staff, and the subdials can rest on hidden studs rather than blocking a lever mechanism. The result is a dial that reads as open space punctuated by information, rather than a crowded surface of apertures. Collectors familiar with the LM Sequential Flyback EVO will recognise the same commitment to architectural legibility across the Legacy Machine line.

Context Within the Legacy Machine Lineage

MB&F, founded in Geneva in 2005 as a horological concept laboratory, has accumulated ten GPHG awards across its two decades — including the ultimate Aiguille d’Or in 2022 for the LM Sequential EVO. The Legacy Machine collection, launched in 2011, has always used the format of the round-cased wristwatch to reinterpret the complications of 19th-century masters through contemporary engineering. The Chromatic editions sit at the confluence of that heritage mandate and a newer ambition: placing gemstone craft at the same level of precision and intentionality as the movement it surrounds. For collectors in the GCC, where coloured stone watchmaking commands serious attention at auction and in private sales, the combination of a GPHG-awarded movement with rigorously sourced baguette stones at this edition size represents a precise and credible proposition. Those interested in MB&F’s broader release calendar can follow new announcements through Watches and Wonders coverage on Watchespedia.

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