Valjoux 7750

File:Breitling Chronomat Evolution.jpg

Breitling Chronomat Evolution with the 7750's familiar 6:9:12 subdial layout

File:Valjoux 7750 Werkansicht.jpg

Valjoux 7750
Breitling Chronomat Evolution, COSC certified

File:Sinn 6000 Roségold RS.jpg

Sinn 6000 Roségold with refined Valjoux 7750

The Valjoux 7750 is a well-known and widely-used chronograph movement produced by Valjoux (part of ETA in the Swatch Group).

History

The 7750 is derived from the manually-wound Valjoux 7733 chronograph movement, itself a descendent of the Venus 188, a company Valjoux purchased in 1966. It was designed (partially on computer, an industry first) by Edmond Capt.

Introduced on July 1, 1974, at the height of the quartz crisis, the 7750 was released five years after the race to build an automatic chronograph was won by Zenith's El Primero and the Chronomatic consortium. It sold well initially (estimated at 100,000 pieces in 1974) but was doomed the very next year. Production stopped in 1975 but demand was so low that supplies lasted into the 1980's. Local management retained the dies and equipment, allowing them to restart production in 1985 as demand for automatic watches rebounded.

Thanks to a durable and inexpensive design and strong support from Swatch Group, the 7750 has become the most common Swiss automatic chronograph movement. Since the takeover of Valjoux by ETA the movement is also called ETA 7750.

This calibre is still produced and is probably the most successful automatic chronograph movement of all times. It serves as basis for several superstructures or modules, including many from other manufacturers. Due to its accuracy and robustness it can also be certified as chronometer. So the manufacturer Breitling, for example, sends all of its watches, including numerous models with the Valjoux 7750 to the COSC certification.

These movements are currently referred to as "ETA 7750" or "Valjoux 7750", but ETA officially calls them "7750 Valjoux" to differentiate them from the Valgranges line. As of 2019, ETA produces the 7750, 7751, 7753, and 7754 as well as the derived ETA A05 line for Tissot and Rado and the larger Valgranges A07 line.

Features

The 7750 is a self-winding chronograph movement with 25 jewels, ball-bearing rotor, unidirectional winding, 1/8-seconds counter, 30-minutes counter, 12-hours counter, 28.800 A/h, power reserve ca. 44 hours.

The key distinguishing features of the 7750 family are as follows:

• Subdials at 6:00, 9:00, and 12:00 for hours, running seconds, and 30 minute chronograph counter, respectively
• Conventional integrated center-mounted automatic winding in one direction (unlike the barrel-wound Chronomatic)
• Cam-controlled chronograph functions using a "heart piece" (unlike the more complex column or pillar wheel style)
• Simple three-plate brass base (rather than complex bridges)
  • Calendar plate with modular components
  • Main plate with off-center center wheel, hacking lever, and simple bent-spring ratchet
  • Top plate with additional winding bridge
• Etachron regulator and balance spring stud

The initial 7750 movement used 17 jewels, but current versions of the 7750 have 24 or 25. It has been supplied at both 21,600 or 28,800 beats per hour, though the latter is much more common.

ETA produces 7750 movements in three finishes:

1. Elaboré
2. Top
3. Chronomètre

Winding	Model	Year	30 Minute Chrono	12 Hour Chrono	Special Features
Automatic	7750	1973	Yes	Yes
	7751	1986	Yes	Yes	Full calendar with hands date, moon phase, 24-hours indication
	7753	2002	Yes	Yes	Minute counter at the 3 instead of the 12, date change by pushers at the 10
	7754	2003	Yes	Yes	GMT function on additional 24-hour hand
	7757	1985	Yes	Yes	Regatta countdown indication
	7758	1985	Yes	Yes	Moon phase
Manual	7760	1985	Yes	Yes
	7761	1986	Yes	No
	7765	1983	Yes	No	Date
	7768	1985	Yes	No	Moon phase

Movement family

• Valjoux 7750 (1973-present)
  • Valjoux 7750-P1, without chronograph module
  • Valjoux 7751 (1986-present), full calendar with hands date, moon phase, 24-hours indication
  • Valjoux 7753 (2002-present), minute counter at the 3 instead of the 12, date change by pushers at the 10
  • Valjoux 7754 (2003-present), 24-hours indication
  • Valjoux 7757 (1985-2003), regatta-countdown indication
  • Valjoux 7758 or Valjoux 7750 CCL (1985-2003), Moon phase (Valjoux 7750 CCL - "con cours de lune")
  • Valjoux 7760 (1985-2005), Manual winding
    • Valjoux 7761 (1986-1998), Manual winding, without hours and day counter
    • Valjoux 7765 (1983-1998), Manual winding, 30-minutes counter at the 12, date indication
    • Valjoux 7768 (1985-1998), Manual winding, moon phase, without hours and day counter
  • Valjoux 7770 (2002-), Automatic, rattrapante
  • Valgranges A07, 16.5 ligne variant
  • ETA A05, Rado/Tissot variant
• Ebauches
  • Alpina AL-725 - with seconds counter removed for a bi-compax design
  • Alfred Rochat, Chronoswiss (C. 732 or C. 741, C 741 by Rochat)
  • Ball RR1104, RR1105 (7754), RR1301, RR1401, RR1402, RR1403 (7751), RR1404, RR1405
  • Bremont BE-50AE
  • Damasko (fitting a Si main spring to the 7750)
  • Fortis, developed by Paul Gerber featuring an alarm and two springs
  • Franck Muller FM 7850 CC MB
  • IWC Cal. 7922, 79320
  • Jacques Etoile (cal. IV.C4)
  • La Joux-Perret (for Jaquet Droz watches for example)
  • Omega 1155 (17 jewels), 1152/1154/1156/1158/1164 (25 jewels)
  • Paul Picot "Atelier Technikum"
  • Panerai
  • Porsche Design (Eterna 6036)
  • Revue-Thommen ("Airspeed Flyback")
  • Sinn ("Flyback")
  • Soprod
  • TAG Heuer Calibre 16
• Clones
  • Sellita SW500
  • Shanghai 3LZF2
• Column wheel variants
  • Panerai OP XVIII by La Joux-Perret (with rattrapante)
  • Hublot HUB 44 aka La Joux-Perret Cal. 8144 (only later versions have a column wheel)
  • Chronoswiss C.732 by Alfred Rochat (with rattrapante)
  • Graham G 1742 by La Joux-Perret (monopusher)
  • Vulcain V-50 by La Joux-Perret
  • ETA A08.L01/A08.231 for Longines (Cal. 688, 788)
  • Omega 3330 by ETA Valgranges (with Co-Axial escapement)
  • IWC 69000 and similar MB 25.10
  • Sinn 910 Anniversary and 910 SRS rattrapante and flyback

Description: Automatic chronograph Escapement: stone lever Yoke winding system Stop mechanism: Cam switching Glucydur balance wheel Nivaflex mainspring Incabloc shock protection Functions: Hours, minutes Small seconds at the 9 1/8-seconds counter, 30-minutes counter, 12-hours counter Rapid calendar advance Hacking seconds Complications: 12-hours counter, day: quickset date feature Data: 13¼ lignes D 30.0 mm, H 7.9 mm 25 jewels 28,800 A/h Power reserve 44h Production period: Since 1973

External Links

• The Valjoux 7750 Engine
• The Valjoux 7750 Chronograph
• The history of the ETA 7750
• The fall and rise of the Valjoux 7750