Dave Rossum is an American engineer and founder of E-mu Systems, one of the most innovative synthesizer and sampling companies of the 1970s and 1980s. His work spans modular analog design, digital sampling, and the custom chips that powered classic instruments.

Before founding E-mu in 1971, Rossum collaborated with Tom Oberheim on the SEM (Synthesizer Expander Module), designing the filter and oscillator circuits that became the voice of Oberheim polyphonic systems. At E-mu he created the E-mu Modular System and, with Scott Wedge and others, the Emulator — the first affordable digital sampler, which revolutionized production by making recorded sounds playable from a keyboard.

Rossum also developed the SP-1200 sampling drum machine and the E-mu Proteus and Morpheus sample-playback synthesizers. After E-mu was acquired by Creative Technology, Rossum founded Rossum Electro-Music, reviving his modular designs for the Eurorack era.

His 2021 return to designing the SP-1200 filter chip and continued Eurorack modules cement his status as a living legend of synthesis technology.

Notable products: Oberheim SEM, E-mu Modular, Emulator, SP-1200, Morpheus.