Arturia Oberheim SEM V Review
Tom Oberheim is one of the big names in the analog synth world. He’s been creating awesome synths since the 70s. His first success was the SEM (Synthesizer Expander Module), which also, is probably one of the most cloned vintage synths out there in the hardware world. In the software world, Arturia has managed to create a very faithful recreation of this iconic synth, with, as usual, lots of extras. Let’s check it out!
The module looks almost identical to the original, with an added keyboard and left-hand controllers pretty much like the ones found in the Oberheim Two Voice (which was in fact two attached SEMs, with keyboard, left-hand controls, and sequencer).
This thing has two VCOs that are identical, both can output Saw or Pulse waves, and anything in between due to its continuous rotary encoder. They can be tuned individually and there’s a hard sync switch right between each VCO, Pulse Width can be adjusted manually from 10% to 90% width, or modulated via Envelope or LFO 1 or 2.
Speaking of modulation here’s another continuous rotary controller ranging from frequency modulation to PWM, and each VCO has its own modulation encoder.
Also, there’s a sub-oscillator that can run 1 or 2 octaves below VCO 1, and can output Sine wave, Ramp or variable Pulse -there’s a PW knob for this-. There’s a continuous knob for outputting sub, external input or noise, and when this is set to 100% sub, things get very fat!
Next is the famous state variable VCF from Oberheim. This is a 2-pole 12dB per octave resonant filter which can be set to anything from LPF to HPF with a Notch in the center position of the encoder and a separate BPF position. Modulation for the VCF can be set both positive and negative amounts, and sources for this, are Envelope 2, LFO 1 or LFO 2.
Speaking of envelope generators and LFOs, there are two sets of ADS EGs and two LFOs. LFO 1 will output just a Triangle wave, and you can set its speed from 0.01 Hz to 13 Hz, so, no audio rate in here, the same happens to LFO 2, but, this, can output Sine, Ramp or Square, also, it can fade in and be retriggered by key. Both LFOs can be synced to the clock for musical values.
This unit has some nice extras on the VCA, like an Overdrive circuit, as well as Chorus and Delay, also, you will find a soft clip switch below the output knob for some extra meat.
Controllers and arpeggiator.
Left-hand controllers include portamento on/off and time, a master tune, and an arpeggiator, which can of course sync to the external clock. This has four modes, as well as four octaves range; modes are up, down, up and down, and random, there’s a hold function for latching notes, but it won’t add new notes, instead, it will release previous notes.
As usual in Arturia’s V emulations, there’s an OPEN button, which indeed opens a whole new world. You will find six extra modules here which are Keyboard Follow, this will make us change how some parameters react to different notes, parameters here are VCO2 Fine-tune, VCF resonance, ENV 2 decay, ENV 2 attack, and LFO 1 frequency.
Next is the 8 voice programmer, and this is only useful if you are using the synth in poly mode: here, you can set each of the 8 voices to be slightly different in terms of VCF, Reso, VCF mode, VCO tune, ENV 1 decay, and VCA Pan. It works like a sequencer, and is especially great if you are playing less than 8 voices because it will cycle through the 8 voices, no matter if you are playing triads or just one note, so, for example, if you set a different VCF cutoff level for each of the voices, and you play just one note, it will cycle each of the 8 voices, creating an amazing effect.
Below this, we find an 8 slots Modulation Matrix with 8 sources being Mod Wheel, Aftertouch, Velocity, Pitch Bend, both envelopes and both LFOs, and 25+ destinations. Amounts can be set either in positive or negative values.
On the right side, we have controls for each of the effects, for overdrive, there’s a drive and a damping knob, for Chorus, two shapes to choose from – sine and noise – rate, depth, feedback, spread and delay, and a button for tempo sync. Finally, for Delay, you can control left and right individual times and feedbacks, as well as buttons for linking both channels, and ping pong, finally, there’s a damping knob and tempo sync button.
This is one of those synths you can recognize by its filter. VCF in Oberheim’s synths is beautiful, very musical, and creamy, and Arturia has done a great job in this department. The filter sounds very close to the original with almost no stepping, and when you hear this synth in action, you know it’s the sound of an SEM, and with the extras, it is not only an SEM, it is also a Two Voice and a SOFV, but, actually, you can play up to 32 voices, so, it’s a beast. As always, MIDI implementation is as easy as it can be, and presets are very well organized and useful.