Memovox

The Memovox (Latin: memo + vox, 'voice of memory') is Jaeger-LeCoultre's alarm wristwatch, launched in 1950 with the hand-wound caliber 489. The alarm is set with a second crown that drives a central disc; when the disc's marker reaches the hour hand, a hammer is released and strikes a pin riveted to the inside of the caseback. The sound is a low buzz rather than the high chime of a repeater, because the caseback is the soundboard, not a set of tuned gongs.

In 1956, JLC released the caliber 815, the first automatic movement to drive both the timekeeping train and the alarm. It was the world's first self-winding alarm wristwatch. The 815 has two mainsprings in series, one for time, one for the alarm, both wound by the rotor. The architecture sets the template for every Memovox that follows.

The 1959 Deep Sea Alarm was the first true dive watch with an alarm, sold in a small US-market edition (about 1,062 pieces) and a larger European version. Inner rotating bezel, screw-down caseback, 200 m rated. The Polaris in 1968 took the same idea further, with a triple-sealed crown system that kept the alarm reliable past 100 m. Original Polaris alarms now run six figures at auction.

JLC retired and re-launched the Memovox several times. The most consequential modern revival is the Master Memovox on caliber 956, plus the modern Polaris Memovox line on caliber 956/1. Today the Memovox is a quiet hero of JLC's catalogue: the only mass-produced mechanical alarm wristwatch on the market, with no real competitor since Vulcain (which makes the only other alarm wristwatch of note, the Cricket).