Rob Papen Blade

IN MUSIC, YOU NEED TO CHOOSE THE RIGHT TOOL FOR THE JOB. FM SYNTHESIS is great at crisp detail, samples are great for realism, analog is great for fatness, and additive synthesis is great at swirling animation.
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IN MUSIC, YOU NEED TO CHOOSE THE RIGHT TOOL FOR THE JOB. FM SYNTHESIS is great at crisp detail, samples are great for realism, analog is great for fatness, and additive synthesis is great at swirling animation. Sure, you can do “fat” with an FM synth or “animated” with analog, but that’s the big picture. Rob Papen’s Blade does additive. It completes the lineup next to Predator (virtual analog), Blue (FM), and Punch (modeled and sampled drums and percussion). Blade has plenty of supporting features, including a multimode filter, effects, and a flexible arpeggiator, but its additive engine is where the action is.


Additive synthesis is a powerful technique. Ultimately, you get individual control over each partial in the frequency spectrum of the sound. Trouble is, that’s a lot of partials. Nobody wants to go crazy adjusting hundreds of envelope parameters. So the folks who design additive instruments always give the user high-level “macro” controls. These controls shape the sound in useful ways, without inducing tweakaholic paralysis.

Blade’s oscillator is called the Harmolator. It’s ridiculously powerful, as you’re about to discover— but to get the bad news out of the way, there’s only one. Some other synths, such as Camel Audio Alchemy (which costs about twice as much) let you crossfade between two or more additive sound sources in a single preset.

Blade’s resonant filter has 14 possible modes, including various rolloff slopes. Stationed before the filter is a per-voice distortion stage for beefing up the tone. The distortion has 20 different modes and a couple of knobs. The filter output is stereo, with a separation knob that off sets the left-side cutoff frequency from the right, again for a richer sound.

Blade has five envelope generators, each with an extra sustain fade time knob. There are four LFOs: one for the Harmolator, one for vibrato, and two general-purpose. Four general-purpose modulation routings are available, plus two more just for the Harmolator, plus two more for the effects. The two effect processors have a choice of 25 algorithms, each with its own set of controls.

Fig. 1. The Harmolator produces up to 96 harmonics, which can be displayed in the Spectrum panel. Other panes show realtime results of modulating the Harmolator, and the waveform produced by the current harmonic spectrum.The most important and interesting feature of Blade is the X/Y Pad. By clicking and dragging, you can record a two-dimensional modulation curve. This curve has separate X (horizontal) and Y (vertical) outputs, each of which can control numerous parameters in the Harmolator and filter. X/Y pads that record mouse moves aren’t exactly new—Native Instruments Reaktor has had them for years. What’s unusual about Blade’s pad is that you can edit your curves (graphically, of course) after recording them. Each sound preset stores only one curve, but if you need more kinds of control over the Harmolator, MIDI controller data can fill the gap.

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Blade’s user interface is easy to work with. Hovering the mouse over any knob displays its current value in an info bar near the top of the panel, and double-clicking a knob centers it. Single knobs or entire modules can be switched on or off with a single click. There’s room for a bit of improvement in the preset manager, which has no way to mark favorites, and organizes the banks of presets by the author of the sounds rather than by type (bass, arpeggio, etc.), thus making it needlessly difficult to find what you’re looking for.


If you’re new to the theory of harmonics, you may find the Harmolator tough to grasp. Briefly, anything our ears hear as a single sound can be analyzed as a stack of sine waves, each with its own frequency and amplitude envelope. There’s a basic pitch, and other sine waves in the stack are called partials. When the frequencies of the partials are whole-number multiples of the basic pitch (the fundamental), we call them harmonics. [A sine wave is a pure tone with no harmonics of its own, and sounds like an oversimplified flute. In fact, the drawbars of a Hammond B-3 organ do very basic additive synthesis, with each controlling the volume of a sine wave. —Ed.]

Yes, the Harmolator produces harmonics, and no, you can’t detune the partials to dissonant, non-whole-number multiples, but there is a Spread knob that creates two or three identical Harmolators and detunes them from one another. A “Sub” knob can introduce a sine or sawtooth sub-octave, which you can also tune up or down by a perfect fourth or fifth. Blade also has chord memory, which is perfect for those techno-trance minor-seventh chord stabs.

The Base knob chooses the loudest harmonic, and the Range knob controls the width of the spread around the base. You can think of these two knobs as operating like a bandpass filter, with the Base controlling the center frequency and the Range the bandwidth of the filter. The Symmetry knob “tilts” the range toward the higher or lower harmonics.

The Timbre knob works with the Timbre Type menu. The menu has 78 types (frequency spectra) that boost or cut various combinations of harmonics. The higher the knob, the more the sound will change when you choose a different type from the menu. The Even/Odd knob is a similar but more basic control, attenuating either the even-numbered or odd-numbered harmonics.

The Harmonic Shift knob introduces a secondary portion of the spectrum, which can be shifted up or down from the Base frequency. There’s a knob for the volume of this secondary spectrum. Just before press time, I got a sneak peek at the Spectrum display (see Figure 1) that’s being added to the 1.0 release. This gives immediate graphic feedback on what happens to the harmonics when you twiddle the knobs, which is extremely helpful.

The X/Y Pad

The idea of the X/Y Pad is simple, but the feature list is long. Until you understand the Harmolator, the controls in the pad won’t make a lot of sense, though you may discover cool sounds just by twiddling knobs.

The central area is a record/playback surface for a two-dimensional modulation shape. You can record this shape by clicking the record button and dragging with the mouse, or by choosing a shape (circle, square, line, or spiral) from the right-click menu. If you use the mouse, Blade will record not only the shape of your moves, but the speed changes, so you can mix fast, jittery movements with long smooth ones in a single curve. As the sound plays, an animated blob on the X/Y surface will move around, showing you the current position.

For both the X and Y outputs, you can modulate up to 12 different sound parameters in various positive or negative amounts. Nine of the parameters are on the Harmolator: Base, Range, Timbre, Even/ Odd, and so on. The other three are filter cutoff, filter resonance, and output volume.

The X/Y shape can play back once per note or looped (with either one-way or back-and-forth looping). Each note can have its own instance of the shape playing back, in which case you’ll see as many animated blobs as the notes in the chord you’re playing, all chasing one another across the surface. Or, the X/Y pad can operate monophonically, so that all of the voices in a chord share a single X/Y output. In the latter scenario, the shape can start over with each new note, or it can free-run. If it’s free-running, you can play a line and get a different tone on each note, which is cool for adding nuance.

The playback speed can be synced to your host sequencer, and can go as long as 16 or 24 bars per loop, so a free-running curve can generate those long modulation curves familiar from electronica. The Speed knob is independent of the sync setting, so the actual speed can be faster or slower than the nominal length of the sync rate. The speed can also be modulated in real time.

Want more? How about editing? The modulation curve can be displayed on the X/Y surface, and you can click and drag to add new bits to it. There’s room for improvement here, though. For instance, graphic editing doesn’t add time to the length of the shape—there doesn’t seem to be any way to do this—so if you add, say, a couple of new peaks or dips to the shape, the sound will zip through them quite rapidly. But most sound designers will probably get along fine using either manual recording or the preset circle and spiral shapes.

In Use

To see if Blade could cut it, I recorded a sketch in Image-Line FL Studio using 11 Blades, plus one Punch for the drums, and you can hear it online. The factory sound set is large and inspiring, but it doesn’t have as many lead sounds as I’d like. A smooth chorused lead tone complemented my groove, so I settled for it. By layering two or three arpeggio patterns or shimmering pads, I got a couple of rich, animated soundscapes.

Adding a complex mod wheel response to the bass tone was easy, but doing a long, smooth fadeout to the final bass note using Blade’s own envelope generator proved difficult, as its envelope times seem to be biased toward tight control of short times. I ended up using FL Studio’s mixer automation for the fadeout.

Programming a few new presets was great fun, and I’m sure I’ve barely touched the surface of what Blade can do. I’ll need a little more time to understand exactly how the controls in the Harmolator interact with one another, or how best to use the X/Y pad in sound design, but I’m sure it will be fun finding out.

I encountered only one minor bug in the version 1.0 release: Occasionally, when I exited the preset manager, the front panel wasn’t redrawn properly. Going back to the preset manager and then exiting it again got rid of the glitch.


Blade is a deep and well-designed synthesizer, with more features than we’ve had space to cover in this review. Its sound palette has a wonderful and sometimes surprising character. The Harmolator additive oscillator can’t detune individual harmonics, and that’s a limitation, but the features in the Harmolator are both extensive and useful—and the modulation possibilities of the X/Y pad invite you to discover new kinds of sound.

No matter how you slice it, Blade is a worthy addition to Rob Papen’s already impressive set of software instruments.

Snap Judgment

PROS Amazing range of tone modulation, including recordable mouse moves. Excellent arpeggiator.

CONS Only one additive oscillator. Harmonics can’t be detuned.

Bottom Line

Powerful tools for making rich sounds with additive synthesis.

$139 list | $119 street