Released in 1981, the Elka Synthex was an Italian 8 voice synth that was one of the first synths to feature digitally controlled oscillators (DCO) to ensure stable tuning. Other notable features include a built-in sequencer (but no MIDI), a 4-axis joystick for modulation and an advanced filter section. It's very fat sounding and can sound quite similar to the Jupiter 8 and Prophet 5.
Some famous users include Duran Duran, Jean Michel Jarre and Stevie Wonder
Sound demos by Åke Danielson. All sounds have some Reverb or Delay added.