Blomman Mr Blue offers a detailed comparison of two vintage Girard-Perregaux Damier references, the manual-wind 7427 and the automatic Gyromatic 7838. His post highlights the subtle yet significant differences in dimensions and aesthetics that distinguish these closely related models, providing valuable insights for collectors interested in the nuances of vintage GP design and movement variations.
Friends,
Yes, you read it right – Damier Gyromatic.
The more well-known Damier ref 7427 with with only hour and minute hands, no second’s hand or date is with a manual movement (GP 25-29/GP26-09).
The less known or seen cousin, the Damier ref 7838 has a Gyromatic movement inside!
Let’s start from the beginning and have a look at the 7838:
At first glance the two looks very similar.
The obvious differences being the second’s hand and the date.
But if you have a closer look at the details you will find more –
The basic characters are the same; square case, thin hands, small crown and of course the Damier pattern on the sunburst dial!
Even if the measurements are very close, the look and feel of the 7838 is more “butch” or “beefier”…
The 7838 measures 29 x 29.5 mm while the 7427 is a tad narrower 29 x 29 mm.
The lugs also differ but the other way around, 7838 is 39.5 mm lug to lug, 20 mm apart and the 7427 is 40 mm, 18 mm apart.
But the biggest difference is the thickness.
Due to the automatic movement of the 7838, the case is thicker, 11 mm vs. 7.5 mm.
These small tweaks plus the fact that the bezel is a tad wider on the 7838 makes the watch feel much larger than the 7427.
The 7838 was a huge success – launched in 1962 and in production all the way until 1976!
A total number of 9.150 pieces were made. 6.850 in steel, 1.350 in yellow gold and 950 pieces in rose gold.
Here shown in an Italian ad from 1965:
How many of these with the Damier dial is not known…
That is an impressive number but less than the 7427 (a total of 18.650 pieces, production between 1958 – 1967).
From my observations, you see much more 7427 with the Damier dial than the 7838.
Since the 7838 is not few in number and also a “younger” watch, my conclusion is that not that many 7838 with Damier dial was made as the 7427 with the Damier dial.
Here is a non-Damier version of the 7838 shown in an Italian catalogue from 1968:
In profile, it is hard to see that the 7838 is thicker than the 7427…
But, if we look at the back of the 7838 we find that the case back is raised, almost like a flattened pyramid.
That is to give space for the rotor.
Compared with the 7427, left, which have a more flat case back.
Here you also notice the different lugs.
7427 with straight lugs and angled tips…
While the 7838 have wider, tapered lugs with straight tips.
From this side, it is easier to see.
Inside the 7838 is the Gyromatic movement, GP Calibre 32-09, based on the AS 1652.
39 Jewels and the Gyrotrons!
Side-by-side, the two cousins – the 7427 (left) and the 7838 (right):
Both dandy-esque watches, but I find the 7427 a bit more elegant and delicate while the 7838 with its extra features is more practical for everyday life!
And the wrist test? Jupp, it sits perfect on the wrist!
Thank you for reading, hope you enjoyed this walk down memory lane…
Best
Blomman
