3940J, First Series, Perpetual Calendar, Yellow Gold

Amongst the most attractive complications to ever leave Patek Philippe, the 3940 was an audacious project from the start. Debuting in 1985 still amidst much uncertainty in Switzerland, alongside the 3970, this was the return of high mechanical watchmaking complication to its home. But where the 3970 continued to evolve prior PCC designs, the 3940 revolutionized the QP. This was accomplished via the ultra-thin micro-rotor calibre 240Q, just 3.75mm tall while retaining chronometric specification and a 48 hour power reserve; a 36mm micro-engineering masterpiece. Fewer than 1,000 examples are widely estimated to have been made in this First Series configuration, with what is one of the most attractive dials Patek Philippe have made. 

With total production of the 3940 widely estimated near 7500 examples, the First Series is by some margin the rarest (accounting for roughly 10% of all production). But it is not scarcity which makes the First Series stand out. Dials of these early productions retain some of the cues of true vintage production. Stern Frére’s difficulty of manufacturing these dials was the overall bottleneck of 3940 production, hence the scale of production growing afterwards. The subdial apertures with their dramatic step were hand-finished, indices hand-applied. First Series production lasted only the initial two years, until 1987. Other identifying traits are the surviving grave accent over the second ‘E’ of Genève. Subdial fonts also include serifs. Here, hallmarks flank the correcting pusher at 9 instead of lug backs. While they’re lost totally with the lightest polish, this example retains them in full relief. First Series mark the handoff from manual production techniques to the later series’ scaled contemporary techniques. 

While First Series are widely considered one type of dial production, this isn’t quite accurate. Stern created two different types named, A and B generally. Type A features a shorter middle branch of the ‘E’, while Type B features equal length bars. Later Singer dials have both a rounded subdial junction and dots in the Swiss & Sigma signature that aren’t on Stern dials (and no Grave accent). This 1987 (sold) example features the second 'Type B' Stern dial.

Recent years have seen the Philippe Stern era of Patek Philippe and its associated austere designs as some of the manufacture’s very best work. On the verge of being considered vintage, these references offer the reliability of modern watchmaking with the tighter proportions and restrained design of vintage production. In early series, these encompass some manual technique as well. While there are many Perpetual Calendars, the 3940 is one which helped the complication rise to fame and desirability. Its role in creating desire for complication cannot be overstated. 

The 3940 has become the defining perpetual calendar of the last half-century. While that’s up for debate, there is no debating that it introduced the world to complicated Swiss mechanical watchmaking at scale and re-established Patek Philippe's prowess in micro-engineering, proportions, and design. Alongside the 3970, this is the very best of complicated Patek Philippe from Philippe Stern’s reign.

This 3940 presents in exceptional overall condition. Its case is very well-preserved, with excellent hallmarks at 9 and only light signs of wear including light surface marks. The dial, comparably, is excellent with no signs of damage and only very light patina starting to develop in the 24-hour counter. The calibre 240Q is running well in specification on our timing equipment. It comes with its original set as well as the then-optional ellipse-style Patek Philippe deployant clasp.

This example is modelled on an average-sized 7-inch wrist.