Valjoux Cal. 7733 is a cam-switching chronograph movement based on the Venus 188. After Valjoux acquired Venus in 1966, the company took the affordable Venus Cal. 188 architecture and launched a new Valjoux-branded movement, Cal. 7730. The only notable change was the use of a mobile stud carrier. Cal. 7731 followed with a different balance cock.
The movement was thoroughly redesigned by Valjoux as the Cal. 7733, launched in 1969. The original excenter adjustable hammer was replaced by a rocker design in 1971. The shape of the hammer was modified again in 1974.
Three related movements were also created: Cal. 7734 added a date function, Cal. 7736 had an hour counter, and Cal. 7737 was a regatta timer. These complications added to the height of the movement: 7733 was 6.00 mm, 7734 was 6.65 mm, and 7736 was 7.40 mm.
Cal. 7733 was the forerunner for the automatic Valjoux 7750, one of the most famous and successful watch movements of all time.