Posted by So, last week we looked at three generations of Jaeger-LeCoultre Chronometers, this week I thought we would have a closer look at three generations of Jaeger-LeCoultre Black Memovox!
Of course there are several combinations of Black Memovox to choose from but I opted for the following three:
E 855 Memovox, E 877 Memovox Snowdrop and 140.97/1 Master Compressor Memovox
Why these three?
Because all three are Black Memovox with automatic movements, date and alarm but with three different Calibres from three different decades!
The Classic – 1960’s
E 855 Memovox, to my knowlage, the very first Jaeger-LeCoultre black dial Memovox with date.
Inside the E 855 is the Calibre 825 which is based on the Calibre 815. The difference between the two is the date complication. To be fair, the Calibre 815 was already in production during the 1950’s, but to my understanding the E 855 and Calibre 825 was only introduced to the market in 1960.
But this document from 1963 indicates that the Calibre 825 movement existed already in 1959.
The Calibre 825 is a bumper movement where the rotor do not swing a full circle which allow a pin on the inside of the case back to be located off centre for the hammer to strike on, see the red marking, showing the hammer located under the bumper rotor.
The Funky – 1970’s
E 877 Memovox Snowdrop was the last of the Funky 70’s Memovox Jaeger-LeCoultre made during the 1970’s housing the Calibre 916 also the only black Jaeger-LeCoultre Memovox with Calibre 916.
Same here, borderline if the Calibre 916 belongs to the 1960’s or 1970’s.
Either way, the big difference between the Calibre 825 and the Calibre 916 is that the later is a full circle automatic movement beating at rate of 28.800 vph (4 Hz), while the older movement beats in a rate of 18.000 vph (2.5 Hz).
Since the rotor swings in a full circle, the alarm pin in the case back can’t be off centre because it would interfere with the rotor. Jaeger-LeCoultre solved this with placing the alarm pin in the centre of the case back. The rotor have a opening in the centre allowing the pin to reach the hammer which is located under the rotor, see the red marking, showing the hammer located under the rotor.
The Beater – 1990’s
140.97/1 Master Compressor Memovox was the first Polaris inspired watch from Le Grand Maison. Not the first nor the last watch using the Calibre 918 but the only real tool watch with this Calibre.
If I remember correctly, the Calibre 918 was introduced in 1994, used all the way to and including the AMVOX I and in 2008 to be replaced with the Calibre 956.
The big difference between the Calibre 916 and Calibre 918 is the alarm complication. From previous “cricket” sound, to “school bell” sound.
The new sound was achieved by a gong attached to the inside of the case back instead of a pin, with a softer, more musical sound. This construction is inspired by the Minute Repeater complication.
Same base: automatic movements, date and alarm – Three very different executions of Black Memovox!
The Classic, the Beater and the Funky one…
A BIG thank you goes out to @jaegerlecoultre_aficionado proposing these stories and for posting them on Instagram!
The Blomman Watch Report 