The 9S5x family of high-end watch movements was the flagship mechanical watch product of Seiko from 1998 until the introduction of the “3 Days” power reserve 9S6x movements after 2006. This range also includes the 8L family of movements, which are used in Seiko Credor, Prospex, Brightz, and Galante models.
The 8L/9S family is intended to compete with limited-production Swiss movements from companies like Rolex. Most are automatic, unlike the ultra-thin Seiko 6800 family, though there are manually-wound versions. The 9S family are carefully finished with Tokyo Stripes and rhodium plating and are adjusted to six positions, while the 8L family has a brushed and gilt finish, with colimaconnage on the rotor and is unadjusted. “9S” models are only used in Grand Seiko watches, while “8L” models are used in other ranges.
The 9S5x family includes many notable Seiko movements
The Calibre 8L and 9S families are assembled at Seiko's Shizukuishi Watch Studio in Morioka, Iwate prefecture, Japan, along with other high-end Seiko movements.
The first members of this family were introduced in 1998. Although fairly basic in terms of complications, they demonstrated Seiko's manufacturing capability and suggested that the company was committed to the high-end watch market once again.
The basic movements in this initial series are as follows
|Automatic||28,800||Hour, minute, seconds||None||None||24||Grand Seiko, decorated with Tokyo stripes, rhodium plated
8L21 is the less-decorated and unadjusted Brightz version from 2005
|Automatic||28,800||Hour, minute, seconds||Date window||None||26||Grand Seiko, decorated with Tokyo stripes, rhodium plated
8L35 and 8L75 are the less decorated and unadjusted Prospex/Brightz versions
|2001||9S54||Manual||28,800||Hour, minute, seconds||None||None||20||Grand Seiko, Tokyo stripes, rhodium plated|
|2001||8L34||Manual||28,800||Hour, minute||None||Small seconds||20||"Railway" pocket watch|
|Automatic||28,800||Hour, minute, second, GMT||None||None||27||Grand Seiko
8L36 was a rare Credor Signo version
|2012?||8L38||Automatic||28,800||Hour, minute, seconds||None||Open heart||26||Galante SBLL017 "Rolling Stones", rhodium plated, fausses cotes decoration|