The Sirius is a keyboard "groove-synth," featuring a subtractive hybrid-tone-generation synthesizer referred to as DTE ('Difficult To Explain') synthesis introduced in 1997 by Quasimidi. The unit featured both real-time and step sequencers with pattern- and song-modes, capable of acting basic drum machine, groove-box, or sound-module. The unit is thus 7x multitimbral and has 28-voice polyphony across its 7 tracks, with track selecting a (track-specific) sound within 96 sounds (per bank) of preset- or user-writeable sounds. Track/voice structure was organized as follows: