Inspired by Aaron's newly-aquired Ref. 6782 Thunderbird, and knowing the collective fondness for V&C's vintage caliber 107x family of automatic movements, I'd like to share some interesting observations regarding one Ref. 6694 which may be viewed as a transitional piece.
This particular white gold 6694 has been presented here before so I'll jump straight to discussions regarding the movement. Manufactured in 1963, as attested by the Certificate of Authenticity, it features the expected K1072 29-jewel automatic movement with date wheel. However, reference in the Certificate is also made to a Gyromax balance! Well, now I have a mystery!
Indeed, upon removing the caseback and examining this oddity, I find it does indeed sport a K1072 and feature the wonderfully ingenious Gyromax balance wheel adjustment mechanism rather than the usual screw-balance with swan-neck fine regulator!
What's up? Well, the Gyromax balance was not new technology when Vacheron decided to license it's use. In fact, Patek Philippe patented the little gizmo back in 1949 and began to install like-fitted movements by 1952 (in combination with a swan-neck regulator during the early years).
So, while it is commonly accepted that the Gyromax was the exclusive privilege of the caliber 1072/1 that became available in 1966, it seems reasonable that earlier experiments were undertaken to prove the worth of this marriage. And what finer showcase for the leading-edge of Vacheron & Constantin haute horologie than the Chronometre Royal Ref. 6694 in elegant (and rarely used) white gold?
My communication with the Heritage Department confirmed that this, indeed, was the configuration upon manufacture. As always, just when you think you have an understanding of things V&C...