UPDATED! Rack Extension Roundup for Propellerhead Reason

Image placeholder title


For years, one of the biggest frustrations faced by loyal Reason users has been that Reason doesn’t host third-party plug-ins. So the fact that, as of version 6.5, Reason’s software device rack has finally been opened up to third-party instrument and effects developers has been greeted with shouts of joy. As of this writing, more than a dozen reasonably priced Rack Extensions from various companies are in the Propellerhead shop, and more are on the way. As we get our hands on them, we'll update this roundup, and send out a Tweet and a Facebook post to let you know.

UPDATE: January 9, 2013: Propellerhead PX7 and Synapse Antidote synths now added!

Reason still doesn’t support VST or AU plug-ins, but if you have a favorite that you’d like to use in a Reason project, you now have a second option: Instead of running it in a DAW and using ReWire to connect the DAW to Reason, you can pester the plug-in manufacturer to develop a Rack Extension version.

The Rack Extensions (REs for short) all use Reason’s familiar user interface, with control and audio jacks on the “rear panel,” realistic knobs and switches on the front, and a bare minimum of pop-up menus. As a result, they’re easy to learn and use. The RE downloads don’t include manuals for the devices, but the manuals seem mostly to be available on the manufacturers’ websites.

On the Shop page of the Propellerhead website, you can buy an RE or download a 30-day trial version. Using the trial version requires an Internet connection, as the 30-day license is stored only on the Propellerhead site, not on a hardware key.

In this roundup we’ll take a look at several of the first instrument REs to be released, and also a selection of RE effects.

Propellerhead PX7

If the 1970s was the decade of the Minimoog and Prophet-5, the 1980s was surely the decade of sampling and the Yamaha DX7. I can still remember the excitement when a DX7 arrived in the Keyboard office for the first time: None of us had ever heard a synthesizer with that kind of crisp, detailed sound.

Image placeholder title

The secret (well, not so secret) ingredient was FM synthesis. The fresh sound of FM wasn’t the DX7’s only selling point — it also had 16 voices of polyphony (unheard of in that era), a velocity-sensitive keyboard, and a phenomenally low price ($1,995) that left the competition in the dust. Also, it was one of the first instruments (though not the first) to hit the street that had MIDI.

Today we have lots of ways to make amazing sounds, but the magic of FM hasn’t faded. In the past decade several software synthesizers have bundled FM with other technologies. Native Instruments FM8, Rob Papen Blue, and Image-Line Sytrus all adopt the DX’s six-operator architecture while adding resonant filters, built-in effects, and palettes of waveforms, none of which were to be found on the original DX7.

Rather than try to rival those do-everything models, Propellerhead (typically for them) chose a slightly different path. Their new PX7 software synth, which is available as an optional Rack Extension for Reason 6.5, aims to be an entirely authentic model of the DX7 itself, from the rate/level envelopes right down to the mud-brown front panel and its graphic stylings. If you were around in 1983, the PX7 will trigger waves of nostalgia. More to the point, the sound of the PX7 is shorn of fancy modern gew-gaws and doodads. You know, like filters and effects. As a result, it’s vintage and yet fresh at the same time.

As if to underscore the point, PX7 ships (or rather, downloads) with banks of presets taken directly from Yamaha’s original voice library for the DX7. Marimba, electric piano, brass, harpsichord, and more—it’s all here. Fortunately, they didn’t try to emulate the DX’s nightmarishly constricted user interface. PX7’s controls are laid out in standard Reason fashion, with one knob or slider for each function and an absolute minimum of hidden features.

In order to talk about the features of PX7, we’ll need to do a brief recap of the original instrument — a quick refresher course for those who weren’t around in 1983. First, though, for those who were around, we should note that while PX7 is 99 percent authentic, there are a couple of significant differences.

First, PX7 is stereo. (The DX7 had a single monaural audio output.) Each operator has a pan control, though naturally the pan pots of the modulators have no effect on the output sound. By panning one carrier hard left and another hard right, you can create various kinds of stereo imaging that were not possible on the original instrument.

Second, and more frustrating, PX7 lacks the DX7’s EG bias implementation. EG bias was a way of controlling the amplitude of any operator directly from the mod wheel, aftertouch, or a breath controller. The most common usage was to program the FM equivalent of a filter sweep when you moved the mod wheel. To do that, PX7 needs a little help.

Here’s the workaround. If you need this type of performance control (and it’s hard to see why anybody wouldn’t), simply park the PX7 in a Reason Combinator module, and then use the Combinator’s Programmer panel to route mod wheel moves to operator amplitudes. Problem solved.

Third, the front panel adds macro sliders for brightness, touch (velocity sensitivity), and attack and decay time. These controls are applied across all six operators. The brightness slider boosts or cuts the amplitude of modulators, not carriers, and it won’t boost any of them past their maximum level, so if a modulator’s level knob is already up all the way, boosting the brightness slider won’t push it any further. Likewise, the touch slider only addresses the levels of modulators in response to velocity, not the levels of carriers.

Fourth — and this is getting really tweaky — if a modulator envelope’s level 4 is non-zero while level 1 is zero, on the original DX the operator’s amplitude would start at the non-zero level and fall back to zero during the time of rate 1. This is not how PX7’s envelopes work. Each modulator always starts a new note with an amplitude of zero. As on the DX, however, a non-zero level 4 for a carrier will cause the notes you play to sustain forever.

DX-style FM synthesis makes use of six operators. An operator combines a sine wave oscillator, a four-stage envelope generator, and a keyboard scaling curve—plus, of course, several controls for frequency. The six operators are laid out on the PX7 panel as horizontal rows of controls. Each operator can be tuned across a wide range, and can either track the pitch of the keyboard or be set to a fixed frequency.

The other key concept is the algorithm. An algorithm is a configuration of the six operators. Each operator can be a carrier (meaning we hear it) or a modulator (in which case its output modulates the frequency and thereby changes the sonic character of a carrier). PX7 duplicates DX7’s original 32 algorithms, including the positioning of the feedback loop. Thanks to an interactive graphic along the right edge of the panel, you can see at a glance which operators are carriers and which are modulators.

By modulating the frequency of one audio-range sine wave with another, you can produce an incredible variety of tone colors, ranging from subtle attack transients, beautiful chimes, and fat basses to nasty grinding noises. Programming good sounds using FM, however, has never been a stroll in the park, because of the sheer complexity of the possible interactions among the operators. As with a box of chocolates, you never know quite what you’re going to get.

Each operator has controls for modulating the amplitude from velocity (with a range of 0 to 7) and LFO (range 0 to 3). The depth of LFO pitch modulation is global, not per operator — but when you set an operator to the fixed low-frequency mode it can be used as a separate vibrato LFO, so more complex pitch wobbles are possible.

All of the parameter ranges of PX7 correspond to their original DX7 counterparts. Keyboard rate scaling of envelope speed, for instance, is 0 to 7 for each operator. In a nod to modern synth design, however, the envelope rate sliders have 99 (rapid) at the bottom of their travel and 0 (slow) at the top, so they operate the way we intuitively expect them to.

Rate/level envelopes are somewhat more flexible than ADSR envelopes. An an envelope can, for instance, have an instant attack, fall quickly to zero, and then rise again toward the sustain point. Level 4 does not have to be zero — and if it’s not zero for a carrier, the notes you play will never die away. It’s also possible to program transients that are heard when a key is released.

The keyboard scaling curves of PX7 operators are exactly like those on the original, with parameters for break point, left and right curve type (plus or minus linear or exponential), and left and right depth. These controls affect the loudness of the operator. They’re extremely useful for avoiding aliasing in the upper range of the keyboard and massive clangorous overtones in the low range.

There are on/off switches for each operator (useful while programming), a single rate/level envelope for global pitch, pitch-bend range and global transpose parameters, and a mono voice mode with legato and portamento.

AS to integration with your Reason rack, PX7’s rear-panel CV inputs are somewhat spartan. It sports the standard CV inputs for sequencer gate and note pitch, inputs that duplicate the mod wheel and pitch-bend controls, and inputs for the four macro sliders (brightness, touch, attack, and decay).

The good news is, each operator has its own CV input for amplitude. This adds a lot to the possibilities for programming new sounds. (Note, however, that when an operator’s envelope goes to zero, the rear-panel input won’t boost it up again.) From the Programmer panel in a Combinator, you also get access to the algorithm choice and the operator feedback amount. The former could be interesting as a way of letting you switch between two rather different sounds from a Combinator button.

The other reason to install PX7 in a Combinator is to add effects and then save your sound with effects as a preset. A chorus or delay would be my first choice, and indeed many of the DX7 factory patches benefit from a bit of chorus. When exploring the factory patches, don’t neglect to do so from the Combinator. You’ll find dozens of rich sounds, some with layered PX7s and some that layer it with other Reason instruments.

Reason users can already use basic FM synthesis, thanks to the FM Pair oscillator type in Thor. But Thor’s implementation doesn’t even begin to touch what you can do with PX7. Well, okay, Thor has per-voice filters, and there’s no way to do that with PX7, so there are pros and cons on each side. Even so, if you’re looking for an entirely new palette of tone colors to add to your Reason arsenal, you should definitely download the 30-day trial version of PX7 and check it out.

Synapse Antidote

First impressions can be deceiving. When I downloaded the trial version of Antidote and took a look at it in the Reason rack, I was thinking, “Two oscillators, ADSR envelopes, two LFOs, a multimode filter, effects, an arpeggiator—ho-hum. Seen it all before.” But when I started checking out the presets, my ears perked up. Especially in the dance/trance realm, Antidote kicks some serious butt. And the deeper I got into the feature set, the more impressed I became.

Image placeholder title

The oscillators each have 15 waveforms and a modifier knob. This knob (which can be modulated, naturally) sweeps through a variety of tones, and not always with the expected result. With the Lofi Chords “wave,” the modifier dials in major, minor, or a blend, with either a saw or a square wave. One of the waveforms is noise, and the modifier is a highpass filter. Another wave is a ring modulator, and the modifier adjusts the pitch of the modulating oscillator up or down. Then again, sometimes it gives you pulse width mod.

But that’s only the start of the fun. Each oscillator is actually a complete oscillator bank of up to 24 oscillators, which can be detuned in small increments and spread across the stereo field for massive fatness, or set to an interval (minor or major third, fourth, fifth, etc.) so you can play up to four-note chords from a single key. Each of the oscillator banks also includes a sawtooth sub-oscillator.

The arpeggiator has 20 preset rhythm patterns, and one of its modes is a gate. By sending the gate through the modulation matrix to control volume, you can set up some infectious grooves. The gate pattern has a separate accent output, which you might use to modulate the oscillator modifier or filter cutoff. Or both.

The modulation matrix has five general-purpose routings, plus three more that are dedicated to LFO 1, LFO 2, and the mod envelope as sources. The list of modulation destinations is long, and includes both individual envelope segment times and a number of effect parameters. Antidote boasts seven simultaneous effects, including EQ and compression. The panel is so packed with knobs that they had to hide the three velocity response knobs on the rear panel. There you’ll also find the external audio input (stereo) for using the effects with other signals.

The factory presets include a complete set of TR-style analog drum sounds, not to mention dozens of basses, leads, keys, chord stabs, pads, a decent TB-303, and so on. If you’re doing any kind of music where the word “analog” means something, you won’t want to miss Antidote.

Propellerhead Radical Piano

Image placeholder title

Reason’s stock NN-XT sampler module has a very decent grand piano multisample. What you get with Radical Piano is a lot more control over piano-specific tone tweaks. Radical Piano is not as pristine as some high-end sampled pianos I’ve played, and in fact I actually prefer the NN-XT piano for standard piano tracks, but Radical Piano opens up a lot of new possibilities.

You get three complete sampled pianos: Upright, Home Grand, and Deluxe Grand. (The latter is a Steinway D.) After choosing a piano, you choose a mic setup. Jazz and Close-Mic setups are available for all three, and the Upright and Deluxe also have Floor, Ambience, and Vintage Mono mic modes. Using the Microphone Blend knob, you can crossfade between any two of the above. For example, you can have mostly a close-miked Deluxe Grand with a hint of vintage-mono-miked upright.

The Character knob lets you switch among two dozen timbre-shifted keyboard maps. If you dial toward the “Subdued” end of Character, you’ll get the muffled sound of higher-pitched samples that have been mapped downward, while the “Agitated” settings do the opposite, shifting lower-pitched samples up so they’re bright and brittle. This knob doesn’t affect concert pitch—in fact, there’s no octave or half-step transpose parameter, though there is a fine-tune knob.

Radical Piano has knobs for attack time, decay curve, and release time. It also has three knobs for controlling velocity response. Low and high velocity response are separate, giving you a very good range of ways to tailor the response to your playing style. When the low knob is turned down low, low-velocity notes produce no sound at all. This turns out to be a feature, not a defect: You can depress keys silently (as on a real piano) and then play other keys. When you do this, you’ll hear a very reasonable simulation of an acoustic piano’s sympathetic resonance.

Even when you’re not using this trick, the Resonance level and release time knobs add the sympathetic resonances produced by the body of the piano, its duplex string segments, and the undamped high strings. The resonance release tone needs more highs—there’s too much fundamental and not enough shimmer in the release when you strike a low note hard.

Three knobs in the Mechanics section control the level of the sounds produced by key down (the hammer), key up, and the damper pedal mechanism. The key up sound is realistic—I checked by comparing it with the mechanical sound produced by the action of my Yamaha C3 grand—but it doesn’t respond realistically to performance. On a real piano, if you let the key up gently there is no mechanical sound, but in Radical Piano the sound is the same on every note. Fortunately, this parameter (like everything in Reason) can be automated, so you can turn it down except when you want an excited, percussive performance.

The other knobs are tone controls. A three-band EQ controls lows, mids, and highs. An Ambience section has four reverb choices: small room, large room, hall, and theater. In the Output section are a one-knob compressor and a stereo width control.

Radical Piano responds in a continuous manner to the level of the damper pedal, an excellent feature (and again, one that can be automated). There’s no timbral change when the damper pedal is down: It’s strictly for sustain. But half-pedaling causes the fundamental to roll off, leaving the highs, which is fairly realistic.

A “rear panel” audio input allows a signal to be sent through the resonance, EQ, ambience, and compression stages, so Radical Piano can work as an odd but interesting effects device.

Rob Papen PredatorRE

Though it was beaten to the starting gate by a couple of retro instruments, PredatorRE is the first current-generation soft synth to pop up as a Rack Extension. It’s a sweet addition to the Reason lineup. A bit slimmed down from the VST version of Predator, it’s still a feature-rich instrument, offering three oscillators, dual multimode filters, four LFOs (not including the three dedicated to pulse width modulation), four envelopes, and a 16-step arpeggiator/sequencer. The modulation routings are a bit simpler than in the VSTi, there’s no patch morphing, and the ability to load microtuning scales has been omitted.

Image placeholder title

Comparisons with Reason’s equally powerful Thor synth are inevitable, but PredatorRE and Thor are simply different beasts. The oscillator and filter count is the same, and both have a healthy array of rear-panel I/O. PredatorRE has much more capable effects, more LFOs, and more envelopes, but Thor has the edge in modulation routings, oscillator types, and arpeggiator design. Thor also has a bigger variety of LFO waveforms.

PredatorRE’s oscillators may be analog-style, but they have about a hundred waveforms, all of which respond to pulse width modulation. The waveform selection can even be modulated or automated for PPG-type wave-stepping. The envelopes have a fade tilt control for the sustain segment, and the amp envelope has knobs for attack shape and decay shape. Fade tilt can be positive or negative, so after reaching the sustain point the envelope can either fall to zero or rise back to full-on. Also featured are a vocoder, a 16-step trance gate effect, a nine-note one-finger chord mode with strumming, several portamento modes, and a huge, well-organized, great-sounding preset library.

Around on the back panel are four general-purpose CV inputs; six gate inputs for triggering various things; four CV outputs from the arpeggiator; and left and right audio inputs, which can be fed to the filter, to the effects, or to the vocoder. The gate inputs to the arpeggiator and trance gate work in an odd but useful way: An incoming gate signal restarts the device to step 1. By pairing PredatorRE with a Matrix Pattern Sequencer, I was able to set up longer and more interesting rhythmic cycles than either device can do on its own.

As you gaze upon the mouth-watering front panel, here’s a cautionary note: The knobs in the upper area can be automated, but in the lower (white) area, only LFO 1 and 2 rate can be. Even with this limitation, you won’t run out of sonic treats anytime soon. PredatorRE is truly a monster. 

Korg Polysix

The hardware Korg Polysix synth was widely embraced when it first appeared in 1981, as a lower-cost alternative to the immensely popular Sequential Circuits Prophet-5. There was even a built-in chorus effect, which helped compensate for the Polysix having only one oscillator. It also had an arpeggiator, but only one ADSR envelope, which had to do double duty on amplitude and/or filter cutoff.

Image placeholder title

Most of these features are faithfully reproduced in the Polysix RE (and also in Korg’s VST/AU version, which has been available for several years). The software Polysix has a few extra features compared to the original hardware, including 32-note polyphony, a multi-voice unison mode with detuning, and MIDI velocity response (of course).

The Polysix RE has rear-panel inputs for Reason’s Matrix step sequencer, and also a pair of assignable CV inputs, which can be selected as the source for either of the front-panel External Modulation inputs. These inputs can modulate pulse width, filter cutoff, VCA gain (loudness), or LFO amount. As on the original, the LFO can modulate VCO pitch, filter cutoff, or VCA gain, but only one of the three.

The blue panel of the Polysix is great for provoking an attack of nostalgia among older musicians and vintage synth buffs, but it’s not entirely clear what functionality you’d gain by buying this RE. The Subtractor synth module that’s part of Reason uses the same analog subtractive synthesis method, and it boasts three ADSRs, two LFOs, two oscillators, a multimode filter, and a lot more rear-panel patching possibilities. The vintage sound of the Polysix may be slightly more authentic, though. I’d love to see Korg do a Wavestation RE, as there’s nothing like it in Reason.

GForce Re-Tron

The Re-Tron is a fairly faithful recreation of the fabled Mellotron. According to GForce, Re-Tron reproduces the original tape recordings from the Mellotron library, including a few that have never before been available in digital form. The 25 “tape” banks include the expected classics (such as flute, violin section, and female choir) and a few that may be less familiar (such as French horn and wine glass).

Image placeholder title

Many of the limitations of the original instrument have been preserved. After eight seconds or so, the sustaining notes stop, because that’s how long the original tape segments were. The key range is less than three octaves, from G up to F. And of course the sound quality of the tapes is dreadful. For devotees of vintage 1960s rock, these sounds will fill a real need, but to be honest, I didn’t like the Moody Blues the first time around, and that was 45 years ago.

GForce has added features that expand the sonic range of the Re-Tron without deviating too far from its authentic vibe. The two channels can play separate “tape” banks for layered textures. Each channel has a resonant multimode filter, two ADSR envelopes, an LFO, and an attack start offset knob. With the latter, you can start the note at a point shortly after the recorded beginning of the tone. In the global area are a stereo delay, an ensemble effect, and velocity amount control for the volume and filter cutoff.

The rear-panel features are basic but useful. Each channel has its own CV inputs for pan, level, filter cutoff, filter resonance, and filter envelope amount. There are also outputs from the filter envelopes for both channels. 

FXpansion Etch Red

How could anybody not love a dual filter with overdrive and tons of modulation routings? Whether you’re doing electronic dance tracks or just need a little shimmering stereo animation for a synth pad, Etch Red will take good care of you.

Image placeholder title

Its dual filters can run in series or parallel, and each has selectors for Type and Mode. The four types are Japan, Fatty, S.V.F. (state-variable filter), and Comb. Filter modes include the expected lowpass, bandpass, highpass, two-pole, four-pole, and so forth, the mode choices depending on the selected type. Filter modes are chosen from a knob rather than a menu, an unfortunate design choice that was probably dictated by the limited panel space, but at least the pop-up ToolTip text tells you what mode you’ve dialed up.

Each filter has knobs for input level, cutoff or center frequency, frequency modulation (switchable to LFO 1 or LFO 2), resonance, and output panning. At high resonance settings, the filters will self-oscillate—and that’s just the start of the fun. Each of these parameters can then be modulated by as many as ten different modulation sources, all at once.

The modulation sources are an AHD envelope (attack/hold/decay—gated from a sequencer track or rear-panel gate input), two LFOs, an envelope follower, a variable-speed sample-and-hold, two rear-panel CV ins, a random value triggered from the rear-panel gate, and rear-panel/MIDI inputs for pitch and velocity. The gain for the main modulation sources (envelope, envelope follower, LFOs, and sample-and-hold) can also be modulated, as can the rates of the LFOs. One limitation should be noted: Unlike Propellerhead’s own LFOs, which tend to have lots of interesting waveforms, these are limited to sawtooth, square, sine, and triangle waves. However, the waveshape can be biased using a Morph slider, which adds to the possibilities.

Seven different overdrive algorithms are included, and the drive amount can be modulated using the same modulation sources. The drive can be switched so it’s post-filter if desired. To tame unruly resonant peaks, the output has a compressor knob.

The rear-panel inputs expand the options still further. The envelope follower can track an external (sidechain) audio input instead of the main input signal, for example. Plus, CV outputs from the LFOs, envelope, follower, and sample-and-hold are provided. Etch Red is a versatile module with plenty of sonic power.

Sugar Bytes Filter Pattern

A simple but useful effect module, Filter Pattern does programmed filter sweeps in various rhythms. The rhythm patterns are preset, with no user input, but there are a lot of them, and they can be varied using the Resonance, Sweep Speed, and Sweep Range knobs, each of which is associated with a pop-up menu giving some options.

Image placeholder title

The start of a Filter Pattern pattern is synced to the first moment when its dry/wet knob is non-zero. Once that knob moves, the module free-runs at the current tempo, whether the transport is running or stopped. You can automate the knob move, snapping it to a bar line — but if you start song playback at a later point (while working on your song), Filter Pattern will produce a different sound on each run-through, because it isn’t syncing to the bar lines. This is different from how Reason’s stock pattern-based devices work, and in my opinion it’s not as desirable.

Filter Pattern has a somewhat different sound than Reason’s stock Alligator module, and has a CV input for resonance, which Alligator lacks. If you can deal with the lack of bar line sync, you may love it.

Sugar Bytes Slice Arranger

Feed a boring drum loop into Slice Arranger and it will get sliced up and rearranged, possibly with some notes shifted up or down in pitch and others repeated in a rapid buzz or played backwards. Some of its preset slicing patterns impart swing or triplet rhythms to a straight beat.

Image placeholder title

Like Filter Pattern, Slice Arranger has bar line sync issues. If you start song playback from a bar line each time, you’ll get the same pattern each time. If you start at some other point in the bar, Slice Arranger won’t know it, and the sound of the beat will change dramatically. This is not a good thing.

The knobs are Pattern, Fill 1, Fill 2, and Decay. Each is associated with a pop-up menu; for the Fills, your choices are repeat, up/down, hard, soft, and pong—just twiddle the knobs until you hear something you like. All of the knobs can be controlled from rear-panel inputs, so you can use the Curve output on Reason’s Matrix sequencer to produce different kinds of fills at different parts of the phrase.

Given the bar line sync issue, I’d suggest using Slice Arranger and Filter Pattern (possibly together) to create new audio tracks. Find a pattern or sound texture that you like, bounce it as audio, and then go on developing your song using your new, creative audio loop.

Peff Buffre Beat Repeater

My brother-in-law never reads an owner’s manual. He gets along somehow, but Buffre would defeat him utterly. When I first tried this extremely cool module, it baffled me. It didn’t seem to be doing anything, and clicking on the buttons and knobs didn’t get me anywhere.

Image placeholder title

The key concept is that Buffre is an interactive effect processor. It sends its input audio passively to the output, until it receives a signal telling it to wake up and do something else. When the signal stops, it goes back to being passive.

When you play a MIDI key between D1 and F3, Buffre grabs a short segment of audio from its input and starts looping it, which produces a stuttering or scrubbing effect. Unlike most Reason effects, Buffre is created with its own sequencer track, so you can record your keyboard performance. Or you can send Buffre the note output from a Matrix module to lay down a groove that does things in sync with the transport. I found this a great way to work with it.

Low keys grab longer segments of audio; higher keys grab shorter segments. The pitch-bend wheel shortens or lengthens the segment being looped, and the mod wheel introduces a bit reduction grunge effect. While looping a segment, you can tap the Advance or Backward button (not mapped, unfortunately, to MIDI keys, though they have rear panel gate inputs) to shift the source audio for the loop forward or back in the source audio buffer.

Three stereo sends can transmit the sound of Buffre’s active output (but not the passive signal) to other devices. By automating the on/off buttons for the sends, you can turn Buffre into a complex, interactive signal gate. There’s a lot more to Buffre, but you’ll have to read the manual (downloadable from peff.com) to learn about it. Definitely download the trial version and spend a little time with it. Buffre will wake you up better than a double espresso.

Sonic Charge Bitspeek LPC Vocoder

Reason’s rack already includes a vocoder, which uses banks of bandpass filters in the familiar way. Bitspeek does vocoding using a different technology, called linear predictive coding (hence the LPC in the name). It slices incoming audio up into frames, quickly analyzes the frequency content of each frame, and then creates control signals and a new output audio signal based on its analysis. The audio output can come either from a simple internal synthesizer or from an external input, as on a standard vocoder.

Image placeholder title

You can shift the analyzed data up or down in pitch, adjust the amount of noise (useful for consonants) in the synthesized output, increase or decrease the amount of pitch tracking of the fundamental, and increase or decrease the frame rate. Unlike a bandpass vocoder, however, Bitspeek doesn’t let you map frequency bands in the modulator input onto different output bands.

With low frame rates, Bitspeek has a stepped sound, somewhat like a sample-and-hold. The frame rate can be synced to the transport clock if desired. The maximum frame rate (80Hz) produces a smooth, easily understandable speech output.

Bitspeek has CV outputs for pitch and the volumes of its voiced and noise channels Using these, you can use the analysis data to drive a synthesizer for drone or burbling effects that synchronize in various ways with the source audio. By holding down a four-note sus chord on the keyboard while playing a Subtractor whose pitch and amplifier level were being controlled from Bitspeek, I got a moving chord pattern that reminded me of tracks Joe Zawinul played with Weather Report.

Bitspeek is a fairly specialized module, but it has some real potential for creative sound design.

Polar Dual Pitch Shifter

Doubling a recorded vocal or guitar with a pitch shifter can be an effective way to fatten it up. Polar has more exotic uses, too. It can turn a simple drum loop into a thick texture of unearthly squeals.

Image placeholder title

Pitch shifting requires that the input signal be delayed slightly, so Polar starts with a delay line whose speed can be modulated by an internal LFO or ADSR envelope or a rear-panel CV input. The delay output feeds the first shifter stage, which has pitch shift controls and a feedback knob for sending its output back into the delay. Level, pan, and auto-pan amount knobs control the output. The second shifter stage is identical, except that it also has its own internal delay (not syncable), so that it can echo the first stage. The dry signal also has its own delay, which is handy for lining up the dry signal with the shifted signals so as to avoid flamming.

The pitch-shifted outputs pass through a simple resonant multimode filter, which has LFO and envelope modulation inputs for cutoff frequency. By creating a sequencer track for Polar, you can trigger its envelope and filter key following from a keyboard.

Turning up the feedback on the shifter sections creates upward- or downward-spiraling pitch sweeps. Runaway feedback is both possible and very effective for special effects. The main delay buffer can be locked, either from a front-panel toggle switch or from a CV gate input, which produces a drone tone.

Polar has four shifting algorithms and several CV inputs to play with, and responds to MIDI pitch-bend. There are no aux audio outs from the shifter stages.

Pulsar Dual LFO

Pulsar is a fairly simple utility module, although less simple than it may seem at first glance. It has two LFOs and an AR envelope generator. Each LFO has its own waveform selector and knobs for phase, shuffle, and lag. If you’re in the habit of using a Subtractor as an LFO, you’ll find that Pulsar gives you more options.

Image placeholder title

On the rear panel, each LFO has outputs for both CV and audio signals — four of each, for convenience, two of them inverted. Yes, these LFOs will run at audio rate, so the “low” in “low-frequency oscillator” is something of a misnomer. You can feed the oscillators’ outputs to Thor for FM sounds or to a BV512 Vocoder as a carrier signal. By creating a sequencer track for Pulsar, you can control oscillator pitch (monophonically).

When an LFO is set to its sub-audio range, the shuffle knob biases the output so that alternating wave cycles are longer and shorter. If you sync the LFO to eighths or sixteenths, for instance, this knob will produce a variable amount of swing rhythm feel. When the LFO is running at audio rate, the shuffle knob becomes a waveshaper, introducing new harmonics to the tone. The lag knob smooths out the waveform, eliminating the sharp clicks in sawtooth and square wave shapes; at audio rate, it functions as a simple lowpass filter.

Naturally, LFO 2 can modulate the rate or level of LFO 1. LFO 1’s cycle can also be synced to LFO 2. The AR envelope can be triggered from LFO 2, and can modulate the rate and level of each LFO. On the back panel are CV inputs for each LFO, governing rate, phase, shuffle, and level. Maybe it’s not a ground-breaking module, but you’ll be glad you have it.


If you thought Reason 6.0 was already an amazing platform for creative sound design ... well, you were right, but even so, you ain’t seen nothin’ yet. Rob Papen PredatorRE, PX7, Synapse Antidote, Etch Red, Buffre, Pulsar, and Polar are in the gotta-have-it category. Bitspeek, Filter Pattern, and Slice Arranger, while more modest, are also very cool. But don’t take my word for it: Download the 30-day free trial versions and find out for yourself.

Radical Piano is a very welcome addition to a platform that up to now hasn’t had a dedicated piano module, though the Reason Pianos ReFill (which is both larger and, at $129, a bit more expensive) has been available for a few years. The Korg Polysix, while hardly a breakthrough, is sure to be welcomed by vintage synth buffs.

In this review we’ve tackled only a few of the more provocative Rack Extensions. Others, such as the AudioRealism ABL2, which faithfully emulates the classic Roland TB-303 analog bass, not to mention a handful of cool CV processing modules (ReVolt, the CV Suite Line Mixer, and others) and a raft of studio effects, are waiting for you to discover on the Propellerhead Shop page. Personally, I’m still hoping for a complex CV data processor and a couple of synths that can play microtonal tunings, as these are both long-standing gaps in the Reason feature set. But now that more developers are standing in line to do Reason modules, the future looks brighter than ever.