Arturia's name is synonymous with bringing hardware back to life in software form. Take a browse through its titles and you'll see a growing number of the leading names in synthesizer history, which have been painstakingly recreated to offer the sound of yesteryear through our productions. The reason some synthesizer titles become legends is due to their richness of their sound, their unique and intuitive interfaces and often their slightly quirky nature. With second-hand prices for original synth classics often sky-rocketing beyond their launch prices, we owe a debt of gratitude to those companies who specialize in the development of their plug-in rebirths.
Arturia's latest soft synth is a recreation of Oberheim's legendary Expander, or Synthesizer Expander Module to provide its full title. Famed for its lush sound, it became a popular choice for synth players throughout the '70s and '80s before Oberheim folded in the middle of that decade.
In keeping with the other titles in Arturia's synth range, the heart of this instrument is a faithful recreation of the Expander. Around this core, Arturia have dragged it into the here-and-now, as we'll see, but the voice architecture remains faithful. This is formed from a twin oscillator design, both of which feature sawtooth and variable-width pulse waveforms which can be independently tuned and modulated. Coarse tuning features its own per-oscillator dial, while control-clicking toggles the dial into fine tuning mode, allowing you to create thick detuned voices.
The original Expander's resonant filter was perhaps its most remarkable feature with multimode functionality providing Low-pass, High-pass, Band-pass and Notch options, all of which employ a 12dB/octave slope. While this might sound tame by the 36 or 48dB/octave standards set by so many synths today, the tonal sound-shaping here still offers enormous amounts of flavour. Also in keeping with the original's feature-set are twin envelopes offering Attack, Decay and Sustain parameters. Envelope 1 can be used as a control source for Oscillator 1, with Envelope 2 providing corresponding modulation into Oscillator 2. The new LFO section offers two modules, each offering sine, sawtooth and square waves, both of which can be fed into either oscillator or the filter section.
Arturia's bespoke additions to the original's control set continue with three onboard effects processors, with Overdrive, Chorus and Delay algorithms. Although these can be dialed in and out with Dry/Wet rotary dials, the best way to tailor effects settings to your mix is to click the Open button in the GUI's top right-hand corner, which launches an extension window, the right-hand section of which lets you focus on the parameters of each effect in turn. Overdrive provides Drive and Damping rotaries, while Chorus offers two shapes, plus Rate, Feedback, Depth, Spread and Delay controls, plus the option to sync the effect to tempo. This function is also offered by the Delay module which provides full stereo operation with Time and Feedback controls for each side of the stereo image plus a Ping-Pong delay option and a global Damping control.
This additional window also provides access to Arturia's most significant additions to the sonic potential of their SEM recreation, via three windows labeled Keyboard Follow, 8-Voice Programmer and Modulation Matrix. Keyboard Follow allows you to select up to six parameters and set "offsets" for them across the keyboard range. Suppose, for instance, you wanted Cutoff to be set wide open at the bass and treble extremes but wanted a more muted sound in the centre around C3? No problem; simply draw the break-point envelope shape in this parameter's dedicated lane.
Other parameters on offer are Resonance, filter Mode, VCO2 coarse and fine-tuning parameters and the frequency of LFO1. Used carefully, you can apply different filter types to different areas of the keyboard, for instance, which is a powerful feature. If you're playing an Arpeggiated or Sequenced sound triggering one of the in-built patterns, the 8-voice Programmer will help bring your sounds further to life. This features an 8-stage step-sequencer which lists six parameters (Cutoff, Resonance, Filter Mode, Oscillator Coarse Tuning, Envelope 1's Decay and Pan) and allows you to create "offsets" per note as the sequence plays through.
As with the Keyboard Follow options, all of these parameters can be activated with offsets at once, so generating a pattern which bubbles with resonance, pans from side-to-side and offers different notes and pitches from one step to the next is powerful. Lastly, if the original's Expander's Modulation routings seem too limiting, the Modulation Matrix should supply the control you need with eight Sources, 26 Destinations and Amounts, controllable with either positive or negative offsets. The Matrix offers eight locations so, once again, it shouldn't prove tricky to add wizardry to the sounds you build.
On the subject of sounds, presets are organized into banks of sound types but the aspect they have in common is their sheer richness. Choose a lead, a bassline and a pad and your mix will be full and deep, with the warmth and power of the original Expander pouring out of your speakers. Hearing faithful recreations of classic Expander patches is wonderful enough but with Arturia's extras, this really does feel like a classic pimped-up for a whole new generation of devotees. Ready to roll within 32- or 64-bit projects, there's little doubt that if you're looking for classic analogue sounds to enrich your 21st century productions, SEM has them by the truckload.
