Dynaco was an American manufacturer of hi-fi audio systems popular in the 1960s and 1970s for its wide range of affordable but high quality audio components.
Its best known product was the ST-70 tube stereo amplifier. It also manufactured other tube and solid-state amplifiers, preamplifiers, radio tuners and bookshelf speakers.

Founded by David Hafler and Ed Laurent in Philadelphia, Pennsylvania, in 1955, it originally sold tube amplifier kits under the name DynaKIT in 1955.
David Hafler sold Dynaco in 1968 to Tyco Inc. but remained a consultant until 1971. He then worked at Ortofon for a while and then founded the Hafler company, which was basically the same as Dynaco from the beginning. The Hafler company still exists and manufactures unique power amplifiers.

Dynaco was liquidated in 1980, and today the brand is owned by Radial Engineering Ltd.