Alexander Matveevich Poniatoff (Russian: Александр Матвеевич Понятов, 25 March 1892 - 24 October 1980) was a Russian-American electrical engineer.
Poniatoff was born 25 March 1892 in Aisha, Zelenodolsky District, Tatarstan, Russian Empire. He emigrated from Russia to China, where he worked for the Shanghai Power Company until he emigrated to the United States in 1927. He founded, in 1944, the Ampex company, using his initials, A.M.P., plus "ex" for "excellence" to create the name. The high-frequency bias technique, which made quality recording possible, was invented by Telefunken engineers and put in to practical use by Poniatoff. Danish engineer Valdemar Poulsen's original magnetic recorder was previously only usable for telephony recording. In 1956, engineers of Ampex created the world's first rotary head recorder, the VR-1000 videotape recorder. Poniatoff served as president of Ampex until 1955 when he was elected chairman of the board. He died in 1980.