In 1988 the no date 9581 was Seiko’s first GS after the brand was abandoned in the early seventies, as the Grand Quartz was in the late seventies. Seiko rebranded Grand Quartz into Grand Seiko, with GS still on the dial however. In reviving the GS as a quartz collection it was crucial that they develop a quartz module to live up to the GS name and standard. A bit like the revolutionary Lord Marvel 36000bph. Here too, Seiko did “time only” to get the best results.. A little later in 1988 date was included and the caliber was named 9587, the more practical watch possibly.
The movement is a Seiko Quartz Cal 9587A, with 7 Jewels, 32’768 Hz, Thermal compensation, it is Anti-magnetic, and has an accuracy of +10 sec per year, (with a 3-year battery life). It still is one of the world’s most accurate watches, 20 years onward. It is also one of the cheapest ways to get a GS.
The quartz module is better than previous “thin” Seiko modules. In fact this caliber was later re-designated 9F83. It is equipped with a unique Twin Pulse Control high-torque stepper motor which makes each second hand movement in two fluid pulses to reduce energy consumption. Instantaneous Date change occurs over just 0.5 milliseconds, while a backlash auto-adjustment mechanism eliminates stepper error. Furthermore, the movement module is air-tight, ensuring the stepper rotor and lubricants are protected from particles of dust. This last feature maintains optimal performance for an estimated period of 50 years before requiring a service.
One cannot ignore that the GS Quartz is in fact the ultimate GS, more so than modern mechanical GS. Owning a GS Quartz is wearing a timepiece in which the Grand Seiko ideals of precision have been fully incorporated.
In 1992, the last year of 9581 production - but not the 9587 which was discontinued in 1994 - the GS line not evolved into the 9F movement but was also extended by the caliber 8J. Grand Seiko never held back after that and today even has become a brand name of its own.