Original sentence: Yamaha made the first commercially successful digital synthesizer, the Yamaha DX7, in 1983.Yamaha released the Yamaha CS-80 in 1977
Edited sentence: Yamaha released the Yamaha CS-80, often described as the pre-eminent polyphonic analog synthesizer, in 1977 followed by the first commercially successful digital synthesizer, the Yamaha DX7, in 1983