Concepto Caliber C99001

The Concepto caliber C99001 is an automatic chronograph movement with 25 jewels and a frequency of 4 Hz (28,800 beats per hour).

Movement Framework:

The C99001 is basically an ETA 7750 clone movement. Not only is it based on the legendary 7750 architecture, but even the finishing is similar. To the untrained eye, it would be difficult to tell the two movements apart.

The easiest way to tell which movement is in your watch is to look for the logo engraving under the balance wheel. The Concepto C99001 will have a “C” logo, whereas the 7750 will have the ETA shield logo.

Another difference between the C99001 and the 7750 is the fine-tuning device on the regulator.  The C99001 has a unique design which follows the curves of the balance cock.

Watches with this Caliber:

The C99001 is most commonly associated with Sinn watches, and Sinn is completely transparent about using the C99001 their product descriptions.

Interesting Aside: the user manual Sinn links to on some C99001 powered watches actually mentions the ETA 7750, not the Concepto C99001. This is not a big deal in terms of functionality and usage of the features based on the instructions, especially since they are so similar (it also reinforces the information in the section above). However, it could cause caliber confusion to owners of C99001 powered watches and 7750 instructions. Newer C99001 powered models link to an updated user manual which has been written to be more generic without mentioning C99001 or 7750.

The C99001 does not appear to be exclusive to Sinn and may be found in other watch brands. For example, Speake-Marin introduced a Spirit Seafire watch at Baselworld 2014 with a calibre C99001-D (date only, without the day of the week). Caliber Corner could not find any sources of Speake-Marin being as transparent about the use of a Concepto caliber, but the 6-9-12 chronograph layout and caliber number suggest that this movement has been available since at least the launch of that model in 2014.

Maurice de Mauriac has also mentioned using the Concepto C99001 in their L3 DLC watches – albeit without the automatic winding unit attached.

In their own words:

“L3 DLC movement Caliber C99001 – Our see-through cases, a blue, anti-reflective sapphire crystal reveals the vibrant caliber. You have the feeling of being able to see and feel the soul of the mechanical automatic movement. The watch is alive. This movement is specially made to our quality standards by Concepto. It is a manual wind movement with hours, minutes and sweep second. Second stop device, eccentric fine adjustment Etachron, 28,800 vibrations per hour, 4 Hz, 25 jewels” –Source

Caliber Corner could not find any examples of the C99001 being used in the current Maurice de Mauriac lineup, but they are using a similar Concepto C8100 manual wind chronograph with a 3-6-9 layout.

Additional Resources:

• Sinn 103 St user manual (pdf)