This is just a copy and paste from Watchtime’s archive and Chinese watch wiki, but I found these articles so interesting that I want to share it with my Chronograph friends:
http://www.watchtime.at/archive/wt_2008_03/WT_2008_03_156.pdf
The fall and rise of the Valjoux 7750 (June 2008)
The Valjoux 7750, the most famous chronograph movement there is, would be just a dim memory if not for the insubordination of the farsighted watchmaker who developed it. This mutinous savior was named Edmond Capt. Capt is an academically trained horological engineer, a native of the Vallée de Joux. In 1970, after studying at the Geneva Technicum and working for a year at Rolex, he returned to the valley of his birth and took a job with Valjoux SA, in Les Bioux, which had long supplied Rolex with chronograph movements. (Valjoux, as you probably guessed, is a contraction of Vallée de Joux.) Soon after hiring him, his new employer presented him with a challenge: Valjoux wanted Capt to develop, as soon as humanly possible, a sturdy, reliable, affordable automatic chronograph with a quick-set day-date calendar. Watch companies had already succeeded in incorporating a self-winding mechanism into a chronograph. Heuer, Breitling, Dubois Dépraz, Buren and Hamilton had joined forces to develop the Chronomatic, and Zenith-Movado had come up with the El Primero. Both movements appeared in 1969. Now the pressure was on Valjoux to introduce its own automatic chronograph. That pressure was made greater by the debut of the first quartz watch, made by Seiko, at the end of 1969. Mechanical-watch firms knew they would need to launch some dazzling technological innovations to keep from being entirely upstaged.
Capt chose as his point of departure the Valjoux 7733, a hand-wound chronograph movement introduced in 1969. The 7733 was a descendant of the Venus 188 (the movement-maker Venus SA had gone out of business in 1966 and Valjoux had acquired its assets). At first, Capt worked on the project alone, but was later joined by Gérald Gander, who had been a student of Capt at the watchmaking school in Le Sentier, and by Donald Rochat. The youthful cadre, which also included another watchmaker and a draftswoman, had one advantage: they were able to use a computer to help them design the 7550. In those days, computers were rare and extremely expensive. Valjoux’s technical director was the only person within reach who had one. He worked in Neuchâtel, about an hour’s drive from the Vallée de Joux, and Capt had to travel there regularly throughout the project in order to digitize his technical sketches and simulate the movement’s kinetic sequences and functions.
The Valjoux 7750 was among the first watch movements developed with the help of a computer. The result was an unorthodox, but durable, precise and reasonably priced device. Instead of incorporating a column wheel, the traditional mechanism for controlling the chronograph stop, start, and return-to-zero functions, the 7750 had a cam system (also known as a coulisse lever system). The coulisse was cheaper to manufacture than a column wheel because its parts were manufactured by stamping. The 7750 had another notable feature: the coupling took place by means of a “rocking pinion†rather than a conventional geared coupling system. When the chronograph button is pushed to start the chronograph, the pinion meshes with the chronograph’s center wheel. When it is pushed again to stop the chronograph, the pinion disengages from the wheel and the chronograph hand stops. This system is not only simpler, but sturdier, than the traditional coupling method.
The 7750’s specs, largely unchanged to this day, included:
• Integrated construction with plated switching cam
• Blocking lever, originally made of plastic, but now made of metal
• Two push-pieces for starting, stopping and returning to zero
• 30-minute and 12-hour counters positioned, for structural reasons, at 12 o’clock and 6 o’clock, respectively
• Running seconds subdial at 9 o’clock
• Date and day displayed in apertures and adjusted via the crown
• Unidirectional winding by means of a central, ball-borne rotor
• Self-winding subassembly that can be removed by unscrewing three screws
• Power reserve of about 42 hours
• Frequency of 28,800 vph, allowing measurements to the nearest eighth of a second
• Etachron regulator-pointer system to alter the active length of the balance spring
• Stop-seconds function
• Diameter of 13 ¼ lignes
• Height of 7.9 mm
• About 250 components
• Weight of 29 grams
The first Valjoux 7750 movements began ticking in 1972 and Valjoux began deliveries in 1973. Production reached 100,000 units per year. In 1975, the Valjoux 7750 fell victim to growing demand for quartz watches and was assigned to the scrap heap. The management of Valjoux ordered the destruction of all 7750 movements in stock and, worse yet, the tools to make them. Capt protested. When his arguments fell on deaf ears, he took matters into his own hands. Capt carefully packed up the tools and movements for safekeeping, and hoped for a brighter future.
THAT FUTURE TOOK EIGHT long years to arrive. It wasn’t until 1983, when mechanical watches had begun their dramatic comeback, that the Valjoux 7750 returned to the scene, thanks to Capt’s foresight in rescuing the tools used to make it. He had left Valjoux SA in 1978, moving to Frédéric Piguet, and Valjoux SA itself had become part of the movement maker ETA, owned by what is now the Swatch Group. (Capt is now a consultant for the Swatch Group’s Frédéric Piguet subsidiary.)
The relaunch was a success, and modifications of the 7750 soon began to appear. In 1985, when moon-phase displays had become popular, the 7750 CCL (con cours de lune) was introduced. In addition to a moon-phase, it also had a datedisplay consisting of a center-mounted hand moving around the dial. The 7751, which was considerably more complex, followed in 1986. It had a full calendar, with a center-mounted hand for the date, apertures for the day of the week and the month, and a moon-phase at 6 o’clock.
In 2002, ETA’s technicians developed another 7750 offshoot, the 7753, with the classic configuration of subdials used in Universal Genève’s famous Tri-Compax from 1942, i.e., the 30-minute counter at 3 o’clock, the 12-hour counter at 6 o’clock, and the running seconds at 9 o’clock. According to ETA, the change was made so that ETA customers would have room at 12 o’clock to place their brand name. Caliber 7753 also has a calendar, shown in an aperture between the 4 o’clock and 5 o’clock positions, and set by a small push-piece on the leftof the case.
(7753: Unidirectional rotor winding, coulisse-lever switching, oscillating pinion, counters for 30 elapsed minutes at the “3†and for 12 elapsed hours at the “6,†date in a window at “4:30,†rapid adjustment of date display via push-piece at 10 o’clock, 28,800 vph, stop-seconds function, 27 jewels, 42-hour power reserve)
The same year, ETA introduced a rattrapante, or split seconds model, the 7770. The rattrapante mechanism is located on the front of the movement beneath an additional plate. ETA eliminated the date display in this model, making it possible to increase the power reserve to 48 hours. Like the 7750, the 7770 has its 30-minute counter at 12 o’clock. One year later, the company released Caliber 7754, which can display the time in a second time zone by means of a 24-hour hand.
The 7750 is also the base for a whole new family of calibers, the Valgranges line, which debuted in 2004. These movements are notable for their size, a remarkable 16 ½ lignes (37.2 mm) in diameter.The lineage of the Valgranges can be traced back to the Panerai brand, which had needed a big, workhorse, self-winding movement with a running-seconds subdial at 9 o’clock and a window-type date display. ETA responded with several large movements: an automatic with date window (the Caliber OP III); a power-reserve model (the A07.161); a GMT model (the A07.171), and a chronograph (A07.211), this last being a conspicuously enlarged 7750.
THERE IS MUCH to admire about the 7750 and its offspring. These movements are famously precise and reliable. In fact, after they’ve been given careful fine tuning, the 7750 and its derivatives breeze through official chronometer tests. Furthermore, the 7750 offers designers many options. They can choose to leave out the running seconds hand, the date display and/or the day indicator. The designer can also dispense with the 12-hour counter or the self-winding subassembly.
Critics do cite some drawbacks. Some watchmakers note the 7750’s relative thickness and large diameter, but these attributes are less problematic in this era of jumbo watches. And, in a watch with a transparent back, the 7750’s size is actually an asset. In addition, some wearers are conscious of the sound the rotor makes. It occurs because the large oscillating weight with its heavy metal segment can reach very high speeds when rotating in its non-winding direction. The sound is unavoidable, however, and shouldn’t be considered a defect. Others complain about the movement’s lack of exclusivity: about 200,000 units of the 7750 are made each year. Big as that number is, though, it isn’t high enough to satisfy demand. The shortage is likely to get worse this year (2008) because, in accord with its agreement with the Swiss Competition Commission, ETA will start to reduce its deliveries of all of its movement kits, including those for the 7750, in preparation for a total cutoff in 2010. (ETA will continue to sell only complete movements.) About 75 percent of all mechanical movements in Switzerland are based on ETA movement kits, so this step will be a painful one for the firm’s customers.
Movement makers are developing substitutes for the 7750. The simplest is an exact replica. Since the patent for the 7750 has expired, nothing stands in the way of this project. Sellita is now hard at work on a clone of the 7750. It hasn’t been born yet, but it has been named: it will be called the SW 500. (edit: Was released in 2011).
In the meantime, ingenious manufacturers in China are producing large numbers of rather coarse copies of the 7750 in various versions. :thumbsup: (see below for more info)
Other 7750 alternatives are more loosely based on the original. La JouxPerret has developed a column-wheel version. Hublot has come up with a highend variation on the 7750, the HUB44, which has components made from an alloy containing magnesium, manganese and aluminum. The movement weighs just 3.7 grams but is very sturdy. Despite the HUB44, Hublot will continue to buy 7750s from ETA. Hublot CEO JeanClaude Biver says, “We’ll continue to purchase from ETA because calibers like the 7750 offer not only reliability and precision, but also a truly outstanding cost-benefit ratio. We surely couldn’t achieve that on our own.†Over the decades, many companies have used the 7750 as a base for more complicated movements.
As early as 1985, IWC Schaffhausen augmented the 7750 with an under-the-dial perpetual calendar mechanism. Components of the 7750 are incorporated in the company’s Grande Complication, with chronograph, perpetual calendar and minute repeater, as well as in the extremely complicated Il Destriero Scafusia. Franck Muller, too, has been very creative in devising attractive modifications of the 7750. Eterna uses the 7750 as a base for the highly complex Porsche Design Indicator, which has four barrels and shows elapsed time via numerals.
The list goes on and on: Alfred Rochat has skeletonized and otherwise modified versions of the 7750; La Joux-Perret, along with other companies, has variations with big date and flyback function. Soprod has modified the 7750 in several ways. In 2001, Paul Gerber, at the request of Fortis, equipped the 7750 with an alarm mechanism. This resulting caliber is the F 2001. From the most humble to the most elaborate, they all owe their existence to one man, the forward-looking Capt, who not only designed the 7550, but saved it from extinction.
Why is the Valjoux so popular
“The Valjoux 7750 is characterized, on the one hand, by its extraordinary toughness and its very good, nearly indestructible self-winding mechanism. On the other hand, it also represents a good cost-benefit ratio. And it’s very easy to service, as long as no work is needed on the mechanism for tallying the elapsed hours, which is a difficult item to service on any chronograph. Some improvements have been made since the 7750 was designed. For example, in the early 1990s, Chronoswiss was the first company to produce and insert a blocking-lever (component no. 8200) made of metal. ETA later adopted this change and incorporated it into its movements.
We therefore regard this caliber as a very contemporary device. Of course, we have no other option, since there’s no other model with a built in chronograph. We would like to see a reduction in the overall height, and would welcome versions with a big date display and power-reserve indicator. But most important of all, we hope that this model will continue to be manufactured for a long time.â€
Gerd-Rüdiger Lang, founder and owner of Chronoswiss Uhren GmbH “
Oris uses the Valjoux caliber in the basic version and in several variations. Its architecture is straightforward, with a clearly defined timekeeping movement and a separate chronograph assembly. The caliber delivers good rate performance and supports numerous options. Other companies also modify and equip it with other features, underscoring the fact that the 7750 provides a solid base for additional functions.
Its service-friendliness also deserves mention: after disassembly, this caliber can be readily reassembled and set into motion again. This movement remains very much abreast of the latest horological developments. We would welcome a version with a power-reserve display or a big date. Delivery delays are quite long, too. Possible improvements could include reducing its height, enabling the rotor to wind the mainspring in both directions, and giving the movement a longer power reserve. But all in all, the 7750 gives us enough latitude for innovations.â€
Hanspeter Schneider, director of production, and Ralf Hilbich, director of product development, Oris SA “
The 7750 is a tried and tested movement without any negative surprises. It’s outstandingly well suited for alterations and additions, such as depicting the time in a second time zone, as Sinn does. Furthermore, it provides many options for technological developments, for example, Diapal technology, where we select special duos of materials that can work together without friction and thus require no lubrication. We’re also satisfied with the range of variations, which leaves plenty of room for us to augment this caliber with our own additions.
One example is Sinn’s SZ02, where we’ve rebuilt the caliber so that it can now tally 60 rather than 30 elapsed minutes. Many watch companies have used the Valjoux 7750, so watchmakers are very familiar with it. This familiarity further enhances its already excellent service-friendliness for retail customers. There’s currently no other movement with a better cost-benefit ratio. This fact makes it all the more important for this caliber to remain available, also because alternatives such as the Lemania 5100 are no longer being made.â€
Lothar Schmidt, CEO of Sinn Spezialuhren
_____________________________________________________________
The A7750 from the Chinese watch wiki:
http://www.tractionink.com/watch_wiki/index.php?title=Mechanical_chronograph
The Liaoning and Shanghai calibres are both automatic and based on the design of the ETA-Valjoux 7750. As far as is known, both were developed in the 21st century.
The first 7750-clones were made by the Liaoning Watch Factory. They have a 21,600 bph escapement, and rotor assembly that differs visually from the ETA. There is a visually impressive, but ineffective micrometer regulator device. Some of the earliest examples of this movement were found in counterfeits of famous Swiss brands and gained a poor reputation for reliability. Later examples of this 21,600bph version seem to be more reliable.
28,800bph versions also believed to be from Liaoning have been seen in some watches. These generally lack the device on the regulator.
The Shanghai 3L chronograph features a 28,800bph escapement, the same as the ETA 7750. It can be visually distinguished from the Liaoning example by a cloverleaf-shaped shockproofing device. Unlike both the Liaoning and ETA movements, the Shanghai features this company's trademark 5 jewel clutch-wheel in the auto-winding module. The cosmetic finish of the plates is more elaborate than on the Liaoning chronographs, and the screws are usually blued. The 3L automatic chronograph is built to a high standard, and has even been adapted for use in space. The movement is a near-clone of the ETA 7750.
Both factories currently offer a variety of sub-dial and calendar layouts mimicking some of the available variants of the ETA 7750. There is also a variant that mimics the layout of the Rolex Daytona, however this is achieved by an aftermarket module that is not from the same source as the base calibre and has extremely poor reliability.
http://www.watchtime.at/archive/wt_2008_03/WT_2008_03_156.pdf
The fall and rise of the Valjoux 7750 (June 2008)
The Valjoux 7750, the most famous chronograph movement there is, would be just a dim memory if not for the insubordination of the farsighted watchmaker who developed it. This mutinous savior was named Edmond Capt. Capt is an academically trained horological engineer, a native of the Vallée de Joux. In 1970, after studying at the Geneva Technicum and working for a year at Rolex, he returned to the valley of his birth and took a job with Valjoux SA, in Les Bioux, which had long supplied Rolex with chronograph movements. (Valjoux, as you probably guessed, is a contraction of Vallée de Joux.) Soon after hiring him, his new employer presented him with a challenge: Valjoux wanted Capt to develop, as soon as humanly possible, a sturdy, reliable, affordable automatic chronograph with a quick-set day-date calendar. Watch companies had already succeeded in incorporating a self-winding mechanism into a chronograph. Heuer, Breitling, Dubois Dépraz, Buren and Hamilton had joined forces to develop the Chronomatic, and Zenith-Movado had come up with the El Primero. Both movements appeared in 1969. Now the pressure was on Valjoux to introduce its own automatic chronograph. That pressure was made greater by the debut of the first quartz watch, made by Seiko, at the end of 1969. Mechanical-watch firms knew they would need to launch some dazzling technological innovations to keep from being entirely upstaged.
Capt chose as his point of departure the Valjoux 7733, a hand-wound chronograph movement introduced in 1969. The 7733 was a descendant of the Venus 188 (the movement-maker Venus SA had gone out of business in 1966 and Valjoux had acquired its assets). At first, Capt worked on the project alone, but was later joined by Gérald Gander, who had been a student of Capt at the watchmaking school in Le Sentier, and by Donald Rochat. The youthful cadre, which also included another watchmaker and a draftswoman, had one advantage: they were able to use a computer to help them design the 7550. In those days, computers were rare and extremely expensive. Valjoux’s technical director was the only person within reach who had one. He worked in Neuchâtel, about an hour’s drive from the Vallée de Joux, and Capt had to travel there regularly throughout the project in order to digitize his technical sketches and simulate the movement’s kinetic sequences and functions.
The Valjoux 7750 was among the first watch movements developed with the help of a computer. The result was an unorthodox, but durable, precise and reasonably priced device. Instead of incorporating a column wheel, the traditional mechanism for controlling the chronograph stop, start, and return-to-zero functions, the 7750 had a cam system (also known as a coulisse lever system). The coulisse was cheaper to manufacture than a column wheel because its parts were manufactured by stamping. The 7750 had another notable feature: the coupling took place by means of a “rocking pinion†rather than a conventional geared coupling system. When the chronograph button is pushed to start the chronograph, the pinion meshes with the chronograph’s center wheel. When it is pushed again to stop the chronograph, the pinion disengages from the wheel and the chronograph hand stops. This system is not only simpler, but sturdier, than the traditional coupling method.
The 7750’s specs, largely unchanged to this day, included:
• Integrated construction with plated switching cam
• Blocking lever, originally made of plastic, but now made of metal
• Two push-pieces for starting, stopping and returning to zero
• 30-minute and 12-hour counters positioned, for structural reasons, at 12 o’clock and 6 o’clock, respectively
• Running seconds subdial at 9 o’clock
• Date and day displayed in apertures and adjusted via the crown
• Unidirectional winding by means of a central, ball-borne rotor
• Self-winding subassembly that can be removed by unscrewing three screws
• Power reserve of about 42 hours
• Frequency of 28,800 vph, allowing measurements to the nearest eighth of a second
• Etachron regulator-pointer system to alter the active length of the balance spring
• Stop-seconds function
• Diameter of 13 ¼ lignes
• Height of 7.9 mm
• About 250 components
• Weight of 29 grams
The first Valjoux 7750 movements began ticking in 1972 and Valjoux began deliveries in 1973. Production reached 100,000 units per year. In 1975, the Valjoux 7750 fell victim to growing demand for quartz watches and was assigned to the scrap heap. The management of Valjoux ordered the destruction of all 7750 movements in stock and, worse yet, the tools to make them. Capt protested. When his arguments fell on deaf ears, he took matters into his own hands. Capt carefully packed up the tools and movements for safekeeping, and hoped for a brighter future.
THAT FUTURE TOOK EIGHT long years to arrive. It wasn’t until 1983, when mechanical watches had begun their dramatic comeback, that the Valjoux 7750 returned to the scene, thanks to Capt’s foresight in rescuing the tools used to make it. He had left Valjoux SA in 1978, moving to Frédéric Piguet, and Valjoux SA itself had become part of the movement maker ETA, owned by what is now the Swatch Group. (Capt is now a consultant for the Swatch Group’s Frédéric Piguet subsidiary.)
The relaunch was a success, and modifications of the 7750 soon began to appear. In 1985, when moon-phase displays had become popular, the 7750 CCL (con cours de lune) was introduced. In addition to a moon-phase, it also had a datedisplay consisting of a center-mounted hand moving around the dial. The 7751, which was considerably more complex, followed in 1986. It had a full calendar, with a center-mounted hand for the date, apertures for the day of the week and the month, and a moon-phase at 6 o’clock.
In 2002, ETA’s technicians developed another 7750 offshoot, the 7753, with the classic configuration of subdials used in Universal Genève’s famous Tri-Compax from 1942, i.e., the 30-minute counter at 3 o’clock, the 12-hour counter at 6 o’clock, and the running seconds at 9 o’clock. According to ETA, the change was made so that ETA customers would have room at 12 o’clock to place their brand name. Caliber 7753 also has a calendar, shown in an aperture between the 4 o’clock and 5 o’clock positions, and set by a small push-piece on the leftof the case.
(7753: Unidirectional rotor winding, coulisse-lever switching, oscillating pinion, counters for 30 elapsed minutes at the “3†and for 12 elapsed hours at the “6,†date in a window at “4:30,†rapid adjustment of date display via push-piece at 10 o’clock, 28,800 vph, stop-seconds function, 27 jewels, 42-hour power reserve)
The same year, ETA introduced a rattrapante, or split seconds model, the 7770. The rattrapante mechanism is located on the front of the movement beneath an additional plate. ETA eliminated the date display in this model, making it possible to increase the power reserve to 48 hours. Like the 7750, the 7770 has its 30-minute counter at 12 o’clock. One year later, the company released Caliber 7754, which can display the time in a second time zone by means of a 24-hour hand.
The 7750 is also the base for a whole new family of calibers, the Valgranges line, which debuted in 2004. These movements are notable for their size, a remarkable 16 ½ lignes (37.2 mm) in diameter.The lineage of the Valgranges can be traced back to the Panerai brand, which had needed a big, workhorse, self-winding movement with a running-seconds subdial at 9 o’clock and a window-type date display. ETA responded with several large movements: an automatic with date window (the Caliber OP III); a power-reserve model (the A07.161); a GMT model (the A07.171), and a chronograph (A07.211), this last being a conspicuously enlarged 7750.
THERE IS MUCH to admire about the 7750 and its offspring. These movements are famously precise and reliable. In fact, after they’ve been given careful fine tuning, the 7750 and its derivatives breeze through official chronometer tests. Furthermore, the 7750 offers designers many options. They can choose to leave out the running seconds hand, the date display and/or the day indicator. The designer can also dispense with the 12-hour counter or the self-winding subassembly.
Critics do cite some drawbacks. Some watchmakers note the 7750’s relative thickness and large diameter, but these attributes are less problematic in this era of jumbo watches. And, in a watch with a transparent back, the 7750’s size is actually an asset. In addition, some wearers are conscious of the sound the rotor makes. It occurs because the large oscillating weight with its heavy metal segment can reach very high speeds when rotating in its non-winding direction. The sound is unavoidable, however, and shouldn’t be considered a defect. Others complain about the movement’s lack of exclusivity: about 200,000 units of the 7750 are made each year. Big as that number is, though, it isn’t high enough to satisfy demand. The shortage is likely to get worse this year (2008) because, in accord with its agreement with the Swiss Competition Commission, ETA will start to reduce its deliveries of all of its movement kits, including those for the 7750, in preparation for a total cutoff in 2010. (ETA will continue to sell only complete movements.) About 75 percent of all mechanical movements in Switzerland are based on ETA movement kits, so this step will be a painful one for the firm’s customers.
Movement makers are developing substitutes for the 7750. The simplest is an exact replica. Since the patent for the 7750 has expired, nothing stands in the way of this project. Sellita is now hard at work on a clone of the 7750. It hasn’t been born yet, but it has been named: it will be called the SW 500. (edit: Was released in 2011).
In the meantime, ingenious manufacturers in China are producing large numbers of rather coarse copies of the 7750 in various versions. :thumbsup: (see below for more info)
Other 7750 alternatives are more loosely based on the original. La JouxPerret has developed a column-wheel version. Hublot has come up with a highend variation on the 7750, the HUB44, which has components made from an alloy containing magnesium, manganese and aluminum. The movement weighs just 3.7 grams but is very sturdy. Despite the HUB44, Hublot will continue to buy 7750s from ETA. Hublot CEO JeanClaude Biver says, “We’ll continue to purchase from ETA because calibers like the 7750 offer not only reliability and precision, but also a truly outstanding cost-benefit ratio. We surely couldn’t achieve that on our own.†Over the decades, many companies have used the 7750 as a base for more complicated movements.
As early as 1985, IWC Schaffhausen augmented the 7750 with an under-the-dial perpetual calendar mechanism. Components of the 7750 are incorporated in the company’s Grande Complication, with chronograph, perpetual calendar and minute repeater, as well as in the extremely complicated Il Destriero Scafusia. Franck Muller, too, has been very creative in devising attractive modifications of the 7750. Eterna uses the 7750 as a base for the highly complex Porsche Design Indicator, which has four barrels and shows elapsed time via numerals.
The list goes on and on: Alfred Rochat has skeletonized and otherwise modified versions of the 7750; La Joux-Perret, along with other companies, has variations with big date and flyback function. Soprod has modified the 7750 in several ways. In 2001, Paul Gerber, at the request of Fortis, equipped the 7750 with an alarm mechanism. This resulting caliber is the F 2001. From the most humble to the most elaborate, they all owe their existence to one man, the forward-looking Capt, who not only designed the 7550, but saved it from extinction.
Why is the Valjoux so popular
“The Valjoux 7750 is characterized, on the one hand, by its extraordinary toughness and its very good, nearly indestructible self-winding mechanism. On the other hand, it also represents a good cost-benefit ratio. And it’s very easy to service, as long as no work is needed on the mechanism for tallying the elapsed hours, which is a difficult item to service on any chronograph. Some improvements have been made since the 7750 was designed. For example, in the early 1990s, Chronoswiss was the first company to produce and insert a blocking-lever (component no. 8200) made of metal. ETA later adopted this change and incorporated it into its movements.
We therefore regard this caliber as a very contemporary device. Of course, we have no other option, since there’s no other model with a built in chronograph. We would like to see a reduction in the overall height, and would welcome versions with a big date display and power-reserve indicator. But most important of all, we hope that this model will continue to be manufactured for a long time.â€
Gerd-Rüdiger Lang, founder and owner of Chronoswiss Uhren GmbH “
Oris uses the Valjoux caliber in the basic version and in several variations. Its architecture is straightforward, with a clearly defined timekeeping movement and a separate chronograph assembly. The caliber delivers good rate performance and supports numerous options. Other companies also modify and equip it with other features, underscoring the fact that the 7750 provides a solid base for additional functions.
Its service-friendliness also deserves mention: after disassembly, this caliber can be readily reassembled and set into motion again. This movement remains very much abreast of the latest horological developments. We would welcome a version with a power-reserve display or a big date. Delivery delays are quite long, too. Possible improvements could include reducing its height, enabling the rotor to wind the mainspring in both directions, and giving the movement a longer power reserve. But all in all, the 7750 gives us enough latitude for innovations.â€
Hanspeter Schneider, director of production, and Ralf Hilbich, director of product development, Oris SA “
The 7750 is a tried and tested movement without any negative surprises. It’s outstandingly well suited for alterations and additions, such as depicting the time in a second time zone, as Sinn does. Furthermore, it provides many options for technological developments, for example, Diapal technology, where we select special duos of materials that can work together without friction and thus require no lubrication. We’re also satisfied with the range of variations, which leaves plenty of room for us to augment this caliber with our own additions.
One example is Sinn’s SZ02, where we’ve rebuilt the caliber so that it can now tally 60 rather than 30 elapsed minutes. Many watch companies have used the Valjoux 7750, so watchmakers are very familiar with it. This familiarity further enhances its already excellent service-friendliness for retail customers. There’s currently no other movement with a better cost-benefit ratio. This fact makes it all the more important for this caliber to remain available, also because alternatives such as the Lemania 5100 are no longer being made.â€
Lothar Schmidt, CEO of Sinn Spezialuhren
_____________________________________________________________
The A7750 from the Chinese watch wiki:
http://www.tractionink.com/watch_wiki/index.php?title=Mechanical_chronograph
The Liaoning and Shanghai calibres are both automatic and based on the design of the ETA-Valjoux 7750. As far as is known, both were developed in the 21st century.
The first 7750-clones were made by the Liaoning Watch Factory. They have a 21,600 bph escapement, and rotor assembly that differs visually from the ETA. There is a visually impressive, but ineffective micrometer regulator device. Some of the earliest examples of this movement were found in counterfeits of famous Swiss brands and gained a poor reputation for reliability. Later examples of this 21,600bph version seem to be more reliable.
28,800bph versions also believed to be from Liaoning have been seen in some watches. These generally lack the device on the regulator.
The Shanghai 3L chronograph features a 28,800bph escapement, the same as the ETA 7750. It can be visually distinguished from the Liaoning example by a cloverleaf-shaped shockproofing device. Unlike both the Liaoning and ETA movements, the Shanghai features this company's trademark 5 jewel clutch-wheel in the auto-winding module. The cosmetic finish of the plates is more elaborate than on the Liaoning chronographs, and the screws are usually blued. The 3L automatic chronograph is built to a high standard, and has even been adapted for use in space. The movement is a near-clone of the ETA 7750.
Both factories currently offer a variety of sub-dial and calendar layouts mimicking some of the available variants of the ETA 7750. There is also a variant that mimics the layout of the Rolex Daytona, however this is achieved by an aftermarket module that is not from the same source as the base calibre and has extremely poor reliability.
