The Valjoux 7750 & MGJVB
As mentioned in our previous articles it is the Valjoux 7750, an automatic chronograph movement, that lies at the heart of each MGJVB watch, as well as numerous other watches around the globe. The Valjoux 7750 continues to be an extremely popular movement used in the majority of chronograph watches on the market today, albeit with variations to the movement and complications added as seen fit.
For example, in addition to the Valjoux being used as the base movement for a number of brands, including Breitling, Omega, Porsche Design, TAG Heuer, Tissot and Hamilton Watch, there are also a number of derivative movements based on the 7750 to create various alternative chronographs from this highly popular model for a number of other brands.
What is the history of the Valjoux 7750 then, you might ask? Well as alluded to in a previous article the Valjoux 7750 was designed by company Valjoux out of a need to respond to a competitors’ designing of an automatic chronograph in 1969, the first of its kind. Valjoux was placed in something of an awkward spot as they needed to respond to their competitors in order to maintain market share. In order to do this they hired famous horologist, Edmond Capt, who designed the 7750, based on the Valjoux 7733, in 1970.
Due to the Japanese Quartz Crisis (another piece of watch history yet to be delved into here) many companies did not survive the 1970s, and this included Valjoux, who became part of ETA, which in turn became part of the Swatch Group. During this time the popularity of mechanical watches took a large hit and the Valjoux 7750 was all but forgotten, in fact the designs had been ordered destroyed by the company, yet were saved by Edmond Capt instead. Then, luckily for the 7750, in the 1980s the popularity of mechanical watches saw a resurgence and it was the need for mechanical movements that saw the Valjoux 7750, an easy to produce-and-distribute watch movement, catapulted back into the limelight and watchmaking history books.
Things that are special about this movement:
- The movement is an automatic chronograph, and although it wasn’t the first, it was one of the first of its time, and continues to be made in production today.
- It can be fitted with a variety of features including a triple date (date, day, month, and moon phase) or a variety of other counters for minutes, seconds, and hours.
- It is available in three executions or “grades”: Elaborated, Top, and Chronometer, denoting the accuracy garnered by each movement.
- The movement is highly adaptable and has had a number of special additions and complications added to it over the years.
- Rather than a column wheel, the traditional chronograph mechanism, this movement uses a 3 plane cam system, known as the coulisse-lever escapement.
- Seen as the bread and butter of watch movements – capable of being stripped down, or built up, to produce a number of beautiful watches with the Valjoux 7750 at the heart.
- Elaborated grade is adjusted in three positions with an average rate of +/−5 seconds/day with a maximum daily variation of +/−15 seconds;
- Top grade is adjusted in five positions with an average rate of +/−4 seconds/day with a maximum daily variation of +/−15 seconds.
- Chronometer grade must meet strict standards prescribed by the COSC: an average rate of −4/+6 with a maximum daily variation of +/−5 seconds.
The Valjoux 7750 was therefore highly adaptable and due to its capability for high production it became very popular and the blood line for many automatic chronographs today. Here at Boutique Von Burg we use a regular 7750 in the Sport II MGJVB models but adjust them to a tighter tolerance during the final assembly, making them within higher specifications. We also use modified 7750 models in our special limited editions models, such as the Roman Rattrapante double chronograph with split second function. We hope you can enjoy a Valjoux 7750 as much as we do at Boutique Von Burg, thanks for reading.