It was five years ago in 2015 that independent watch brand MB&F introduced the Legacy Machine Perpetual — reinventing the perpetual calendar system and wowing watch collectors globally. In fact, it won the GPHG Best Calendar award in 2016. Since then, the watch has been created in 18-karat 5N rose gold, platinum, 18-karat white gold and even titanium. Now, however, the brand really steps out on a limb — releasing the beloved watch in 18-karat yellow gold with bright blue movement parts visible from the front. This also marks only the second time in its 15 years that MB&F has created a watch in yellow gold and the first time was a frosted gold, LM101 Frost YG.
Built in a limited edition of just 25 pieces, the LM Perpetual Yellow Gold is equipped with the same revolutionary movement as its siblings. That movement was developed in cooperation with Irish watchmaker Stephen McDonnell, who opted to use a 28-day concept for the perpetual calendar watch instead of the more traditional 31-day system. In the LM Perpetual, thanks to a patent-pending mechanical processor that controls the date (instead of the usual grand levier system), at the end of every month (except February on a non-leap year), days are added so that the count can reach 29, 30 or 31 as needed. In traditional perpetual calendar watches, the 31-day method eliminates days (by fast-forwarding though the extra dates) to achieve 30-, 29-, and 28-day months. This can sometimes result in skipping dates.
The complex 581-part caliber, with no module and no base movement, reinterprets the look of the calendar because the enter complication, along with its suspended balance, can be seen via the dial-free watch front. Because there are no modules, the entire caliber is fully integrated and offers a nice safety feature: the adjuster pushers automatically deactivate when the calendar changes, so there is no fear of damaging the movement. Additionally, the retrograde leap year indicator has a dedicated pusher to quickly adjust the year, while on most perpetual calendar watches, leap year can only be set by scrolling though the 47 months between leap years.
Not only is the dramatic balance and movement (connected to the escapement on the back side of the movement) eye-catching, but also the entire architecture of this piece is breathtaking. The subsidiary dials that display the calendar information seem to float above the movement thanks to hidden studs.
Details of the Mechanical processor
For those mechanically minded collectors who really want to understand the movement, MB&F offers great detail. “Legacy Machine Perpetual uses a patent-pending “mechanical processor” consisting of a series of superimposed disks. This revolutionary processor takes the default number of days in the month at 28 – because, logically, all months have at least 28 days – and then adds the extra days as required by each individual month. This ensures that each month has exactly the right number of days. There is no “skipping over” redundant days, so there is no possibility of the date jumping incorrectly.
Using a planetary cam, the mechanical processor also enables quicksetting of the year so that it displays correctly in the four-year leap year cycle, whereas traditional perpetual calendar mechanisms require the user to scroll through up to 47 months to arrive at the right month and year.The mechanical processor also enables an inbuilt safety feature that disconnects the quickset pushers during the date changeover, eliminating any risk of damage while the date is changing. While the conception and development of this mechanical processor-controlled perpetual calendar complication is a noteworthy achievement in itself, Stephen McDonnell went even further by managing to place all 581 components of the movement in virtually the same-sized case as LM1.”
Technical Specs: MB&F Legacy Machine Perpetual Yellow Gold
Engine: Fully integrated perpetual calendar developed for MB&F by Stephen McDonnell, featuring dial-side complication and mechanical processor system architecture with inbuilt safety mechanism. Manual winding with double mainspring barrels. Bespoke 14 mm balance wheel with traditional regulating screws visible on top of the movement. Superlative hand finishing throughout respecting 19th century style; internal bevel angles highlighting hand craft; polished bevels; Geneva waves; hand-made engravings.
Power reserve: 72 hours
Balance frequency: 18,000bph / 2.5Hz
Number of components: 581
Number of jewels: 41
Functions/indications: Hours, minutes, day, date, month, retrograde leap year and power reserve indicators
Case: 18k 3N yellow gold
Dimensions: 44 mm x 17.5 mm
Number of components: 69 components
Water resistance: 30 m / 90′ / 3 atm
Sapphire crystals: top and display back treated with anti-reflective coating on both faces
Strap & buckle: Black, grey, brown or blue hand-stitched alligator strap with gold / platinum / titanium folding buckle matching case material.
Retail Price: $167,000
– in platinum 950 with blue face (limited to 25 pieces);
– in 18k red gold with grey face (limited to 25 pieces);
– in 18k white gold with purple face (limited to 25 pieces);
– in 18k white gold with dark grey face;
– in grade 5 titanium with green face (limited to 50 pieces);
– and now in 18k yellow gold with blue face (limited to 25 pieces)