Although I'm not sure of the history before that, Ampeg's generally favorable resurgence in the 90's was after it was acquired by St. Louis Music, one of the big behind the scenes wholesalers who had been around forever, known by most for their partnership / import relationship with Kazuo Yairi and the Alvarez and Alvarez-Yairi brands. The Kornblum family had re-established production through facilities in Arkansas and had really done a good job of re-introducing and re-establishing Ampeg.
Following the passing of the elder Mr. Kornblum, Ampeg was sold to Loud Technologies (based in Washington State, they also own EAW, Mackie, and Martin Audio), another one of these big conglomerates, who promptly shuttered the Arkansas production facilities, canned the production employees, and established production in Viet Nam.
Taking a play from the Henry Juciewicz Method, despite ostensibly lower production costs, they halved the product line and kept prices the same and/or raised them somewhat, forever endearing themselves to most of their dealers. I keep waiting for a YouTube vid of Vic Wooten or Steve Bailey on a factory tour . . . . . lately they've been trumpeting that some items are NOW produced once more in the US of A. Yippeee ! !
J o e y