We first brought your attention to the then-in-development Redux in 207's Renoise 3 review, and we've been looking forward to its release ever since.
Of all the features introduced in version 3 of Renoise, the one that most impressed us was the redesigned sample engine with its Effects Chains, Phrase Editor and per-sample Modulation - and it's essentially this element of the tracker that's been distilled in Redux as a plugin (VST/AU, and SO for Linux).
In a nutshell, Redux is a tool for creating complex sample-based phrases using a tracker- style sequencer, complete with effects and a powerful modulation system. In addition to the samples bundled with Redux, you can load your own (in various formats including WAV, AIF, FLAC and SFZ) via the sample browser or by dragging and dropping from your OS, and even record sounds in directly.
The main area of the interface switches between five tabbed pages: Keyzone, Samples, Waveform, Modulations and Effects. The Keyzone page is where samples are layered and split by assigning them to note and velocity ranges. Samples can also be set to play monophonically with glide in the main options at the top of the interface.
The Waveform page is an audio editor, enabling manipulation of sounds (reverse, cross-fading, rendering with effects, etc) and even drawing waveforms from scratch. As with any wave editor worth its salt, a transient- detecting beat-slicer is incorporated, too, for hacking up loops and assigning the resultant slices to keyzones.
In the Modulations Page, per-note modulation of parameters such as volume, pan and filter cutoff can be applied to each sample on an individual basis or by chaining LFOs, envelopes and other devices together to create modulations far more complex than the sum of their parts.
In the Effects page, each sample or set of samples is assigned its own Effects chain, hosting one or more of the 28 built-in effects modules (reverbs, delays, filters, distortions, etc) and routed to any one of up to 12 stereo outputs in the host DAW. Effects parameters can be automated using Meta devices, which are essentially audio effect equivalents of Modulators, including an LFO, envelope follower and pitch tracker. Eight MIDI-assignable macros also enable automation of individual or multiple Modulation and Effects parameters via a knob.
Phrase sequences in Redux are programmed in the classic 'spreadsheet'-style tracker sequencer, by entering alphanumeric data with the QWERTY keyboard or Redux's context- sensitive virtual keyboard. A Phrase can be anything from a single note/hit or chord to a melodic line, chord sequence, rhythmic pattern - or indeed, a full-on polyphonic, multi- instrument musical passage - complete with special effects commands to define various aspects of sample playback, from the essentials such as volume and pan, through to more unusual functions such as reverse playback and the probability of any particular note playing.
Phrases are then triggered by MIDI, be it live from your keyboard (or other MIDI device) or programmed in the host DAW. In Keymap mode, up to 126 phrases are assigned to individual MIDI notes or mapped across multiple keys, while in Program mode, the selected phrase is mapped across the whole keyboard, with Program Change messages used to switch between phrases. For phrases mapped across multiple keys, MIDI note input can be set to control the phrase start point, transposition, or which sample in a multisample set the phrase will play.
To give a couple of examples: with a kick drum pattern on one phrase assigned to C4 and a hi-hat rhythm on another phrase assigned to D4, pressing C4 and D4 simultaneously triggers them together. By mapping one polyphonic melody phrase across the entire MIDI note range, on the other hand, triggering C4 plays it back at the original pitch, while C5 plays it back an octave higher, and pressing C4 and C5 together would do both.
Redux comes with a good number of preset patches, from glitchy beats and sound effects to atmospheric drones and melodic phrases. The presets are inventive and inspiring, so it's well worth fully exploring their sounds and how they're designed.
While you can, of course, save your entire Redux session as a preset, each tab also has its own preset list, so you could, for example, reuse a lovingly created modulation combo on any set of samples. Renoise instrument presets can also be loaded back into Redux, and this is scheduled to be enabled in the other direction with the next update to Renoise.
For those coming to Redux without prior tracker experience, the Renoise team has done a good job of making the interface intuitive, but it's still a comparatively complex beast, so don't expect an entirely easy ride. There's a lot of fun to be had just using the per-note modulations and effects, but the greatest creative rewards of Redux come from unlocking the potential of Phrases - once you get into that side of its operation, Redux can take you into whole new dimensions of composition and production that you might never have reached in any other way.
Those raised on trackers and already familiar with the Renoise way of doing things, on the other hand, will appreciate the ability to bring that awesome tracker functionality and workflow to their 'conventional' DAW.