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: Kick drum - 1 voice sample through synthesis chain Snare drum - 1 voice sample through synthesis chain Hi-Hat - 2 voice samples (open/closed) through synthesis chain Percussion drum kit - 12 samples through common synthesis chain (chromatic) Synth 1 (chromatic) Synth 2 (chromatic) Synth 3 ...where the first 4 tracks can only load patches from 2 banks (1 ROM and 1 User) of 96 User patches of that instrument, but all 3 (chromatic) synth parts can load from a common pool of 4 banks (3 ROM and 1 User) of 96 keyboard patches.
The onboard pattern sequencer allows for storage of 1600 motifs (MIDI sequence only) to freely assign to sound within Patterns, holding 142 ROM and 100 User Patterns (assignments between motif and Program). The Sirius can store holds 16 Songs, where each Song assigns 8 patterns 4 breaks (fills pattern to change all parts) 4 special loop tracks (momentary-action fill for single Part) settings for 2 bus effect settings for vocoder
User Interfacing
A distinct layout of front-panel buttons allow for quick and direct selection assignment of tracks to specific voice-patches (within each back of 96), by pressing the Part Select button for the track desired selecting one of 6 Categories button for drum/synth types pressing of 16 buttons in the Sound Select mode. ...with categories of: Natural Drums / Bass-Sounds Dirty Natural / Dirty Bass 909-type / Plucked-Sounds 808-type / Solo-Sounds Drum-SFX / Effects-Sounds
While the "genre" buttons remain fixed to a single purpose, the 7 Track buttons allow for per-track Part Select, Part Mute, and MIDI sequence routing. The 16 buttons perform multiple duties, including: selecting 1 of 16 Songs when running patterns w/in a Song, selecting 1 of 8 Patterns , and triggering 1 of 4 Breaks (triggered fills) and/or 1 of 4 Special Loop tracks (momentary pattern variations). Sound Selection
Sound Synthesis and Control
In addition to level and pan controls, each track could also be routed to 2 effects engines; 1 for reverb/delay, 1 for modulation delays (delay/chorus/flanger). It also features an 11-band vocoder with flexible track routing to its carrier and/or modulator, and an advanced/programmable arpeggiator/gate-sequencer for automatic rhythms controlled by its 49-note keyboard.