Cal. 7760 is a hand-winding cam-switching chronograph movement with day and date wheels. Closely related to the popular Cal. 7750, Cal. 7760 is somewhat thinner at 7.00 mm thanks to the elimination of the automatic winding rotor. It retains the familiar 6-9-12 subdial layout. It is also closely related to Cal. 7765, which lacks the day wheel and hour counter.
Note that a version of Cal. 7750 with registers at 3 and 9 was commonly called “Cal. 7760” prior to the introduction of this hand-winding 6-9-12 version.
ETA Cal. 7760 Variants and Ebauches
IWC uses the 7760 ebauche for their Cal. 76xxx movements, including Cal. 76061 (with a perpetual calendar module and tourbillon) and 76240 (with a rattrapante and small seconds module). The third digit “2” indicates that the movement uses a TRIOVIS regulator rather than the familiar Valjoux regulator.
Tutima uses a modified 7760 (without the hour counter) in their Classic Flieger model.
ETA 7750 Family Overview
The ETA (formerly Valjoux) 7750 is a robust and reliable automatic movement with an integrated cam-operated chronograph function. It has spawned a family of chronograph and time-only movements and is used as a base for many complications and third-party watch movements.
Introduced in 1974, the Valjoux 7750 was soon retired but returned in the 1980s. It has come to dominate the industry and remains popular today. Most versions of Cal. 7750 feature small seconds at 9:00 and chronograph hours and minutes subdials at 12:00 and 6:00, respectively. This “6-9-12” subdial arrangement is instantly recognizable to watch enthusiasts.
Distinguishing features of the ETA 7750 family include a smaller balance wheel than many historic movements and a small rotor hub with a slotted screw and five visible bearings. The balance is located at 1:30 when viewed from the back with the crown at 9:00, and is located by a clockwise cock. The distinctive Valjoux regulator was used on most 7750 variants until the 2010s, with a clamp-shaped arm and “dagger” pointer. The chronograph functions use cams rather than the levers and column wheel found on many other movements.