By Geary Yelton

THE FIRST SYNTH I OWNED WAS AN OBERHEIM TVS-1 FROM THE MID ’70s. It housed a pair of monophonic Synthesizer Expander Modules (SEMs), giving it two complete and independent synthesizers as its voices. Because the TVS-1 had no memory, I had to manually dial up new patches on both modules to change sounds. A few years later I got an FVS-1—a large model with four SEMs and partial patch memory. I eventually sold it to buy my dream synth, an Oberheim Matrix-12. After I began using soft synths in the studio more often than hardware, I became frustrated that you could get accurate emulations of practically every classic synth except an Oberheim. Luckily, Arturia—best known for spot-on re-creations of classics such as the Sequential Prophet-5, Roland Jupiter-8, and Yamaha CS-80—recently launched SEM V, which emulates Oberheim’s SEM-based instruments and goes far beyond.

Synth Engine

Tom Oberheim introduced the SEM in 1974 as a monophonic expander for existing synths such as the Minimoog and ARP 2600. Both the original SEM and the new models that appeared in 2010 are freestanding boxes containing two voltagecontrolled oscillators (VCOs), a multimode filter (VCF), a sine wave LFO, and two envelope generators. The oscillators can be synced and generate sawtooth and variable-width pulse waves. The two-pole filter comes in four flavors: lowpass, highpass, bandpass, and notch. The envelopes have attack, decay, and sustain knobs and modulate the amplifier and filter frequency. With only three knobs to control each ADSR envelope, the initial decay and the final release times are identical, and a single knob controls both parameters.

SEM V’s architecture and front-panel layout are faithful to their hardware counterparts, but with significant additions. A second LFO offers sine, sawtooth, or square waves, and you can sync it to your host software’s tempo, as well as determine how quickly its effect fades in. A versatile sub-oscillator generates the same three waveforms, either one or two octaves below the frequency of VCO 1. I was pleased to find you can apply pulse-width modulation to the sub-oscillator’s square wave. You also get a white noise generator and some effects (overdrive, chorus, and delay) as well as a basic arpeggiator that spans up to four octaves. Clicking the Open button at the top of the window reveals Modulations and Effects sections above the front-panel interface.

One of my favorite tricks with my old TVS-1 was to play it monophonically with portamento turned on for only one SEM. However, in SEM V, portamento is applied to all voices.

Extended Programming

On a vintage Oberheim four- or eight-voice synth, you could either layer all the voices at once (unison mode), trigger them one after the other (continuous mode), retrigger the same voices (reset mode), or assign specific SEMs to either half of the keyboard (split mode). SEM V duplicates continuous mode when played either polyphonically or monophonically. Arturia says there’s no unison at this time, but SEM V sounds so fat in mono mode with the sub-oscillator on that I could have sworn there was.

Because a separate SEM generates each voice in a vintage Obie, every voice differs slightly from the others, even when parameter values are identical. This partially accounts for its huge sound, and SEM V’s unique “8-Voice Programmer” section mimics this by letting you off set parameters for each of eight simultaneous timbres. The Programmer displays six modulation routings, each with a pop-up menu for selecting from 24 parameters that include VCO tuning, VCF mode, LFO rate, and the timing of individual envelope segments. To their right is a window that resembles a step sequencer, with graphical blocks you can resize, representing parameter values for each voice.

Although SEM V lacks a sequencer, you can duplicate one by setting one of the Programmer’s modulation routings to affect oscillator pitch, selecting a pitch for each of the eight voices, and turning the arpeggiator on so that it retriggers each note.

SEM V’s Keyboard Follow function is more sophisticated than your average keyboard tracking. Like the Programmer, it can modulate six simultaneous parameters of your choosing. Each of the six assignments has its own response curve controlling how the affected parameter responds to note position. For each curve, you can define as many as 32 breakpoints and specify whether the slopes between breakpoints are linear or exponential. The Keyboard Follow section is where you can make your SEM V patches stand apart from those of other synths.

Another page reveals SEM V’s Modulation Matrix, which lets you define sources, amounts, and destinations for up to eight mod routings. You can choose from eight sources— including either of the envelope generators— and 26 destinations that include vibrato and filter resonance.

Batches of Patches

SEM V is loaded with hundreds of outstanding patches, many created by top synthesists such as Ian Boddy, Drew Neumann, and Erik Norlander. Banks are further divided into types such as Bass, Percussive, Sequence, and so on. Although bread-and-butter-type sounds aren’t especially plentiful, many of them are terrific.

The 8-Voice Programmer mimics the subtle variations between SEMs in a vintage Oberheim by letting you offset parameters of your choosing.

Conclusions

I’m impressed by how well SEM V captures the sound of Oberheim hardware, and its extended features make it more flexible than its namesake. I commend Arturia on reproducing the SEM’s filter characteristics. SEM V is one of the most genuinely analog-sounding soft synths yet. If you love the sound of vintage synths, SEM V should be part of your virtual rig.

Snap Judgment

PROS Sounds like a real Oberheim SEM. Versatile sub-oscillator and second LFO. Unexpectedly deep and subtle programming capabilities.

CONS Portamento can only apply to all voices at once. CPU-intensive.

Key Info

SYNTHESIS TYPE Analog modeling.

POLYPHONY Up to 32 voices, user-adjustable.

FORMATS Mac or Windows. AU (Mac only), RTAS, VST, standalone.

COPY PROTECTION eLicenser Control Center software—Internet connection required for initial authorization.

Bottom Line

If you’ve always wanted the legendary and nearly unattainable Oberheim Eight-Voice, this is the soft synth for you.

$249 list | $199 street
arturia.com