Reference 1663406 is the Master Grand Tourbillon, a Master Grande Tradition piece rather than a Master Control one, and the JLC Master Grand Tourbillon 1663406 makes no attempt at Master Control restraint. The bezel is set all the way round with baguette-cut stones, the hour markers are baguette gems laid straight into a deep blue aventurine dial flecked white like a night sky, and an open tourbillon fills a wide aperture at six o’clock. The cage turns once a minute inside a graduated pink gold flange, read by a dark pointer, so the tourbillon doubles as the only running indication on the dial. It is a fundamentally different proposition from the simpler time-and-date pieces in this range, and it sits in haute horlogerie territory rather than in the dress-watch bracket the rest of this category occupies.

Build Details

• Case diameter: 43mm
• Case material: pink gold finish, bezel fully set with baguette-cut stones
• Dial: deep blue aventurine with baguette gem hour markers and the tourbillon aperture at 6 o’clock
• Crystal: sapphire front with anti-reflective coating and exhibition caseback
• Strap: black alligator leather with folding buckle
• Movement: clone Cal. 978, automatic tourbillon, 28,800 vph
• Functions: hours, minutes, tourbillon visible at 6

The 43 mm case gives the tourbillon cage room to be read at arm’s length, and the aventurine around it is doing just as much work: the white flecks shift as the wrist turns, so the dial never sits still. Through the exhibition caseback the finishing of the bridges, beveling, and rotor decoration is fully exposed, adding visual interest from both sides of the wrist. The dual-side sapphire crystal approach means the movement is never hidden.

What Collectors Notice

Tourbillons in this segment separate the display pieces from the daily wearers. The 1663406 leans toward the former, though the 43 mm pink gold case and automatic winding keep it practical enough for regular rotation rather than permanent safe storage. Jaeger-LeCoultre has historically produced its tourbillon cages and escapements in-house, a distinction that collectors value when comparing across different manufactures. For the other mechanical showpiece on this shelf, look at the Geophysic True Second 8018120, which puts its argument into a seconds hand that jumps once per second instead of a rotating cage. Both are listed in the Master Control category here, though the 1663406 belongs to Master Grande Tradition and the 8018120 to Geophysic.

This vs Other Versions

Master Control references are built around restraint. The 1663406 is not one of them, and it does not pretend to be: Master Grande Tradition is where Jaeger-LeCoultre puts the movement on the dial and the stones on the bezel. At 43 mm it also wears larger than every 39 mm reference shelved beside it, and it keeps only hours and minutes, with no date and no central seconds to share the space. The JLC Master Grand Tourbillon 1663406 presents the complication on its own terms, in a case sized and dressed for it rather than for the rest of the collection.

Nothing else in the category this listing is filed under runs a tourbillon or a 43 mm bezel set with baguette stones, which is the clearest sign that the 1663406 is shelved here for convenience rather than lineage. How a clone tourbillon compares with the brand’s simpler automatics is covered in our full JLC super clone verdict.

Specifications

• Model: JLC Master Grand Tourbillon 1663406 (Master Grande Tradition)
• Reference: 1663406 (Q1663406)
• Case: pink gold finish, bezel fully set with baguette-cut stones, 13.3 mm thick
• Case size: 43 mm
• Dial: deep blue aventurine, baguette gem hour markers, polished pink gold rail around the centre
• Complications: open-worked tourbillon at 6 o’clock with a graduated flange, no date, no central seconds
• Movement: clone Cal. 978, automatic tourbillon, 28,800 vph
• Power reserve: 44 hours (genuine Cal. 978: 48 hours)
• Water resistance: 50 m (same as genuine)
• Crystal: sapphire
• Strap: black alligator leather with folding buckle