An analog board was used in which third model of the Macintosh line?
Analog board:  The analog board was one of two circuit boards within many early Macintosh computers, including the Macintosh 128K/512K/Plus, Macintosh SE series, and Macintosh Classic series. Macintosh Plus: The Macintosh Plus computer is the third model in the Macintosh line, introduced on January 16, 1986, two years after the original Macintosh and a little more than a year after the Macintosh 512K, with a price tag of US$2599.
Macintosh Plus