The vintage Seiko offering crazy accuracy that’s still flying under the radar

Jason Marsden

Whilst many will argue as to what exactly constitutes a vintage watch, more and more collectors are looking to include quartz, from analogue to classic LED and LCD models. For myself the pinnacle, and one that remains constantly on my watch list, is the Seiko Twin Quartz.  These watches offer outstanding accuracy, far surpassing most quartz watches produced today, equalled only by high-end Grand Seiko quartz and beaten only by the limited production Citizen Caliber 0100.

For some, an old quartz is an old quartz, and this has kept these very special watches under many people’s radar.  A twin quartz watch is most easily spotted by the double quartz logo on the dial, this graphic doubling up on the common single quartz tuning fork logo used by Seiko.

Introduced in 1978, the twin quartz overcame the main accuracy issue that faces quartz watches: temperature.  Movement, shock and orientation have no effect on quartz accuracy unlike mechanical watches, but they are affected by changes in temperature.  The twin quartz movements overcame this by having one quartz crystal handle the normal oscillation for the time circuit, while the second crystal is dedicated to measuring the temperature and compensating for changes.  This results in a staggering accuracy of around +/- 10 seconds per year.  Yes, you read that right, per year.  The Seiko Twin Quartz Superior range brings this down to +/- 5 seconds per year!  By comparison a modern quartz watch will typically be around +/- 15 seconds per month.

At the high-end of the modern quartz market, the Grand Seiko 9F achieves +/- 10 seconds per year and the Citizen Caliber 0100 +/- 1 second per year.  Grand Seiko achieve their accuracy by specially treating and aging crystals for three months, then custom matching the timing circuit programme with a temperature reading taken every 160 seconds, 540 times a day.  Citizen took a radically different approach replacing the traditional tuning fork shaped crystal with a solid cushion shape (known as an AT cut) that vibrates at over eight million hertz, 256 times faster than a normal quartz oscillator.

I don’t obsess over accuracy in my watches, I know I have many vintage mechanical watches that are running well out of specification.  Most likely some of my modern mechanical watches will be losing or gaining  tens of seconds per day.  For me improving their accuracy significantly would be very frustrating, and lead to a large expenditure of dollars and effort on calibration above normal servicing.  However, there is something to be said for knowing that a 40-year-old watch is today still more accurate than the vast majority of modern watches.  For anyone who does chase ultimate accuracy outside of connected watches, then Seiko Twin Quartz would be the ideal foray into the vintage scene.

These watches have a timeless elegance and designs that are very wearable today.  Some feature textured dials and finishes that Seiko has become well known for.  It is worth remembering that these watches were created as the top tier, and the refinement was not just on the external visible portions of the watches, the jeweled movements incorporate metal base plates and other parts.  A small word of warning, you may find some Twin Quartz watches have a burnished integrated bracelet- if you are looking to purchase one just confirm that this bracelet has not been cut too short as they cannot be extended once cut.

Today a Twin Quartz watch can still be found for under a couple of hundred US Dollars.  You may even strike someone selling a Superior at a great price. Keep you eyes peeled if you want to stay right on time.