Red Sound Darkstar

Ins & outs: the dark side of the Darkstar. (click for a close-up)

The Darkstar's synth engine is divided into four main parts: oscillators, envelopes, LFOs, and the filter. Most key parameters are editable by the front-panel knobs, though the frequent necessity to use the Shift buttons can be stifling. To assign special routings, you must venture into the menu, which is accessible by the same buttons used to select the 64 preset sound programs.

If you're the type who hates reading manuals, you'd better get over it if you want to use the Darkstar. (Hey, they're just bleached sheets of wood pulp; they won't bite.) Though the Darkstar's menu is not that deep and shouldn't be too intimidating to beginners, some functions, particularly saving edited sounds, require a look at the manual, and even then it's a little tricky the first few times.

Oscillators

Sawtooth and square waves are available for each of the two oscillators, but oscillator two can also be set to a formant oscillator with a limited band of frequencies, white, pink, or blue noise, or one of the external inputs. For each oscillator, pitch and pulse width can be modulated by either one of the envelopes or LFOs, and oscillator two can be offset by as much as 24 semitones (two octaves). The oscillators can also be synced together or detuned by +/-2 semitones. The joystick mixes the levels of the oscillators and also the degree of ring modulation applied to each one. It's a nice feature, but the ring mod is nowhere near the shrieky metallic quality of classic ring modulation. But with no effects onboard, it is still a welcome addition.

The modulation routings of the oscillators are what make this section most exciting, but note that the Pulse Width control, and hence Pulse Width Modulation, will only affect the width of square wave oscillators.

Envelopes

Four ADSR knobs control the two envelopes, the first of which is hard-wired to amplitude, and the second is assignable to the filter, pulse width, or oscillator pitch. These four knobs also control the level, panning, tremolo, and portamento of each of the five synth parts. There are also eight levels of velocity sensitivity for the envelopes, so that notes played hard on the MIDI keyboard will open the envelopes more than softly struck notes.

Low-Frequency Oscillators

Kudos goes to the Darkstar's LFOs. Seven shapes -- sawtooth, triangle, square, sine, pulse, sample & hold, and random -- are available for each LFO, and they can be synced to incoming MIDI Clock at 15 different trigger rates, from thirty-second note to four bars. Three knobs control speed, delay time, and shape of the selected LFO. In all, one or both of the LFOs can modulate panning, tremolo, oscillator pitch, pulse width, filter resonance, or filter amount.

A Darkstar's Vocoda option ($49) includes a front-panel overlay like this. (click for a close-up)

Filter

The filter is also nicely spec'ed, but unfortunately its sound is a little weak. The 12dB per octave filter can be set to lowpass, bandpass, or highpass, or turned off. The resonance can be modulated by the LFOs or envelopes, and a knob controls the level of modulation. Additionally, the filter amount can be modulated by LFO2. External audio can pass through the filter, but only from a MIDI instrument … too bad. The word from Red Sound is that with the Vocoda vocoder upgrade ($49), non-MIDI sources can go through the audio inputs.

As a bonus, you can set the filter to open more for low notes than high notes and vice versa at several levels of intensity. Filter cutoff and resonance can also be assigned to the joystick for extra expressiveness.

Results from the filter were a mixed bag. It can execute some nice sweeps and squelchy resonance, and it should do the trick for many applications. But sometimes when I wanted severely earth-shaking low end or ear-piercing highs, the filter didn't always come through. A toggle between a 12dB and 24dB filter slope would also be nice.

MIDI and Beyond

The five parts of the Darkstar can be all be played on the same MIDI channel by assigning different note values to each part, or each part can be assigned to its own channel. You can also stack oscillators to fatten the sound by copying parts and assigning them to the same notes and same MIDI channel. Through the menu, settings can be made for the pitch-bend, mod wheel, and aftertouch of the MIDI controller. Should the 64 program memories not be enough, you can do a sys-ex dump of the memories into a MIDI sequencer and start over.

Many corners were evidently cut to make the Darkstar the most affordable analog emulation synth on the market. As a result, the interface is not luxurious, nor can it match the sheer scope of analog sounds you'll get with a Novation Supernova, Access Virus, etc. Yet despite this, the Darkstar delivers a lot of very cool sounds -- punchy basses; sharp synth leads; an array of swirling, burbling, and drippy noises -- and a lot of fun.

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