Dave Smith won a Grammy for his technical achievements. Aside from being the primary inventor of MIDI, Dave is the brains behind milestone technologies like the first programmable analog polyphonic synth (the Sequential Circuits Prophet-5), digital vector synthesis (the Prophet-VS), wave sequencing (the Korg Wavestation) and the first soft synth (Seer Systems Reality). With a résumé like that, what do you do for an encore? Release the Prophet 12, of course. Dave calls it the finest synth he’s ever designed. After spending some quality time using it, we think he’s being modest.



Four oscillators that include virtual analog, wavetable, FM, AM, and multiple hard sync options—plus sub-oscillator. Dual resonant lowpass and highpass analog filters. Extremely comprehensive modulation routing. Tons of realtime performance features. Dual stereo outputs. Two simultaneous synths can be layered or split. Sounds tremendous.


Not everyone can afford three grand for this experience. Unlike Poly Evolver, no step sequencers onboard.

Bottom Line

Not only is the Prophet-12 the finest synth Dave Smith has yet designed; it’s also the finest hardware synth for synth geeks currently on the market.

$3,299 list | $2,999 street



First off, the Prophet 12 (P12 for short from here on) is not a workstation. It’s a synthesizer for players who love synthesis. While its oscillators are digital, its filters and amplifiers are analog. While some purists might pause at the oscillators not being real analog, I think they’re missing out in this case. For one, the oscillators’ virtual analog waveforms are rendered so smoothly that even diehards will quickly forget that they’re listening to digital. Second, the P12 goes so far beyond analog capabilities that everyone will be too busy creating and playing amazing sounds.

The high-level architecture of the P12 is as follows: There are two supremely capable synths running simultaneously. You can layer them, split them, or have both play the same sound, either in monophonic unison or with 12-voice polyphony. Dual stereo outs let you process each synth differently and MIDI over USB lets the P12 quickly fit into studio rigs. There’s also a plethora of performance tools like two touch-strip sliders for realtime modulation, aftertouch as well as velocity sensitivity, and a pair of arpeggiators waiting to percolate as you play. As to factory presets, there are 792 to be exact.

But other synths can say a lot of the same things, so why’s the Prophet 12 so special? Because of its synthesis engine. As synthesizers go, this one is a Pacific Rim-sized sea monster. So let’s rip it open and dive inside the innards.


The Prophet 12’s digital oscillator section is the deepest and most flexible I’ve ever seen in a hardware synth. Even more impressively, its knobs are laid out in a way that makes it extremely accessible to new users. In addition to the de rigueur coarse and fine tuning knobs, there’s a clever array of parameters that all affect the sound in dramatic ways, regardless of the selected waveform. The sonic variety available in the oscillator section alone is so broad that I got lost in it for several hours before remembering that I hadn’t yet touched the analog filters.

Skating across the surface of the oscillator section, you’ve got 19 waveforms to choose from: Four classic analog waves (sine, triangle, square and sawtooth), 12 digital wavetable options, and three noise generators. Each waveform is affected by the Shape Mod knob in a pronounced manner. For the analog waves, this knob adjusts the duty cycle of each waveform. On a square wave, this knob adjusts the pulse width in classic fashion. On a sawtooth or triangle wave, it does a similar trick, but with vastly different sonic results. In simplest terms, the Shape Mod knob functions as a way to manipulate the structure of each waveform without getting all mathematical ’n’ stuff.

The digital waveforms are a brilliant implementation of Dave Smith’s revolutionary work on the Prophet-VS and the Korg Wavestation. When one of these waves is selected, the “Wave Right” and “Wave Left” options on the P12’s OLED display become active. From there, you can select two different digital waveforms. Then, using the shape mod knob, you can smoothly morph between the three waveforms’ harmonic spectra, yielding thousands of waveform permutations, depending on what you’ve selected.

The three noise waveforms are red, white, and violet. Here the Shape Mod works a bit like an EQ, allowing you to “tilt” the frequency spectrum of each. For newcomers, red noise has emphasized lower frequencies, violet noise emphasizes highs, and the classic white noise is more balanced. In practice, the Shape Mod knob can blur those lines considerably.

Remember, we’re still only talking about one oscillator here. There are four of these babies in the P12, plus a sine wave sub-oscillator that tracks the first oscillator. Taking everything up a notch, you can do much more than simply mix the oscillators. The P12’s oscillator bank also includes FM, AM and sync tools for all four oscillators.

In a manner that reminded me of Rob Papen’s brilliant soft synth Blue, the P12’s oscillators can do all kinds of sideband tricks that you just don’t see in hardware synths. Better still, despite the underlying complexity of the technology, the default implementation is pretty straightforward once you learn the basics.

With hard sync, the oscillators are all connected to each other in a cascading manner. That is, oscillator 1 slaves to oscillator 2, oscillator 2 slaves to oscillator 3, and so on, with oscillator 4 slaving to oscillator 1. The whole concept flows like a big circle, which is why Dave designed the front panel with a big silkscreened circle around the oscillator select buttons.

Frequency Modulation and Amplitude Modulation synthesis tools are configured in a very similar manner. In both instances, the lower-numbered oscillator functions as the carrier. Again, the “circle” topography holds: Oscillator 1 is the carrier and oscillator 2 is the modulator, which is then modulated by oscillator 3, and so on. If you’re familiar with FM synthesis, it’s easier to think of this implementation as reminiscent of algorithm 1 on Ableton’s Operator soft synth or on a Yamaha DX9. (I’d say DX7, but since the DX9 had four operators, it’s the closer analogy.)

If you want to go even further down the rabbit hole, you can use the P12’s modulation matrix—and we’ll get to that in a bit—to alter these modulation routings in even more complex ways.

Rounding out the oscillator tools are per-oscillator glide/portamento, key follow on/off, wave resetting (so the oscillators always begin “speaking” at the same point in their wave cycles), and the clever Slop parameter, which lets you dial in analog-style pitch drift in subtle to copious amounts.


The Prophet 12’s innovative “Character” section further sculpts the oscillator bank’s output with five unique parameters that operate on a per-voice basis before they hit the filter section. The parameters are as follows: Girth, Air, Decimation, Hack, and Drive.

The Girth and Air parameters function like a cross between shelving EQs and harmonic enhancers. In practice, these work a little bit like Aphex Aural Exciters, with extreme amounts of Air adding high-frequency sparkle. Cranking the Girth knob to max is also a bit like the Aphex “Big Bottom” feature, boosting low-end warmth in extremely musical ways. These two knobs alone will be a huge benefit for live performance, allowing keyboardists to EQ their patches before they hit the mixer.

The Decimation and Hack knobs are essentially an integrated bit-crusher, with Decimation modifying the sample rate and Hack reducing the bit depth of the oscillator output.

Finally, the Drive knob is a fantastic addition for more analog-style patches, adding overdrive and saturation enhancement to the overall tone of the oscillators. It’s worth noting here that the Drive knob interacts with the oscillators’ frequency modulation tools in an extremely intense manner, so if you’re dabbling with FM as you work and things start to spin out of control, double-check this parameter. In many cases, a little goes a very long way.

Next: Filters, Modulation, Envelopes, and more! 


The P12’s filter bank is arranged as a resonant lowpass filter followed by a two-pole resonant highpass, which is both reminiscent of a Roland Jupiter-8 and far more flexible than a simple multi-mode affair.

The lowpass is Curtis-based, as with the Prophet ’08 and the rest of the DSI product line. It can be switched between two- and four-pole modes, with four-pole mode capable of self-oscillation. The lowpass section includes all of the essential amenities for classic subtractive synthesis, including a dedicated ADSR envelope, keyboard tracking (which is fantastic when the resonance is self-oscillating), bipolar envelope amount, and a knob for controlling the amount of velocity modulation to the cutoff.

Synth geeks know that the Curtis chips deliver a super-creamy lowpass response that’s almost too smooth for some users. Personally, I love the sound, and since the Prophet 12 includes so many options for sonic destruction, the smoothness here is yet another useful color in its palette. So, no complaints from this camp.

The highpass filter section is more streamlined, with three knobs for cutoff, resonance, and keyboard tracking. Again, as with almost everything on this synth, you can add an envelope via the modulation matrix if you’re craving it.


The Prophet 12’s voltage-controlled amplifier section includes all the essential knobs, as well. In addition to a classic ADSR envelope, there are pots for overall envelope amount, velocity control of volume, and a Pan Spread knob that makes voices alternate between left and right in varying amounts.

The soft section of the amplifier parameters includes control over the master distortion parameter (said distortion is stereo and analog, by the way), whose knob is on the opposite side of the keyboard. It doesn’t bug me that this knob is located elsewhere, though. It’s just something to be aware of as you find your way around this synth.


Following the VCA section are two additional effects, each with Dave’s fingerprints all over them.

The first section is dedicated to a tuned feedback effect. Fans of the DSI Poly Evolver will be happy to see its inclusion here, as it’s an incredibly cool sound to apply to leads and sound effects. In fact, the Poly Evolver’s tuned feedback was one of the main components of the lead sound in my track “Yin” (with Wolfgang Gartner) and tweaking the P12’s feedback knob brought back lots of memories of those studio sessions.

Basically, this section takes the signal and runs it through a tuned resonator, which tracks the keyboard so its pitch follows your riffs—polyphonically, I might add. The two knobs are amount (both positive and negative) and overall tuning, so you can set it to an interval or octave of your patch’s original tuning. On some sounds, it lends a Sitar-like quality. On others, it’s absolute mayhem. While you may not use this effect every day, it’s great to have in your bag of tricks.

After the Feedback section, there’s a four-way multi-tap digital delay. This can be synced to tempo or set manually with eight-bit resolution. While I would have preferred the ability to dial in exact millisecond amounts, there’s a useful reference in the manual that charts the values to their corresponding times.

There are four switches that select the delay line to be edited, and three knobs for the essential parameters: time, amount (mix), and feedback. Syncing the delays to tempo is accomplished at the OLED screen. Turning this on switches the values from zero to 255 to rhythmic note values, speeding up your composition process greatly.

Having four separate delay lines available simultaneously means that you can easily set up everything from twisting, polyrhythmic riffs to short room reverb emulations. Again, as with almost everything in the P12, the delay times can be modulated by things like envelopes and LFOs, which means that these delays can also serve as independent chorus or flange effects if you brush up on your sound design technique.


While all of these audio parameters on their own would make for a powerful synth, the Prophet 12 is absolutely overflowing with possibilities. In fact, it’s darn close to the range of amenities you’ll find on a well-stocked modular synthesizer.

The P12’s four LFOs rely on classic analog waveforms: triangle, up saw, down saw, square, three kinds of pulse, and random (or sample-and-hold if you’re feeling hardcore). The addition of a Slew Rate parameter makes these standards far more versatile than usual.

What’s slew? It’s kind of like adding portamento—or a lag generator—to the LFO waveform itself. For example, a square wave with a longer slew rate will slide up and down to its peak, instead of jumping abruptly between two values. This is an especially cool parameter to use with small amounts of “random” modulation, as it can introduce minor variations much like analog voltages do.

Speaking of analog voltages, the P12’s LFOs do another trick that’s usually reserved for modular gear. That is, their rates extend far beyond low frequencies and well into the audio range. This extended range lets the Prophet’s LFOs do some really gnarly tricks with sidebands, especially when applied to destinations like the VCA or delay times.

In addition to four LFOs, there are four envelopes. All are ADSR affairs that also include a delay time before the initial attack stage. As previously mentioned, two are dedicated to the filter and amplifier sections, respectively, but these can also be used to modulate other parameters. The other two envelopes are fair game for routing to pretty much any parameter.

Which brings us to the truly vast array of modulation destinations, which include exotic options like FM amounts, AM amounts, the aforementioned oscillator Shape Mod, delay tools, any of the character parameters, tuned feedback, and panning. Things get even more interesting—and complicated—when you throw in a bunch of even more obscure routings like modulating the attack time of a single envelope with an LFO, or the rate of an LFO with velocity.

Making matters even more blissfully complex is the fact that there are up to 16 possible modulation routings per patch (in addition to the standard fixed routings). So you can use LFOs and envelopes within a patch and then create additional performance routings for the pitch wheel, mod wheel, the two touch-strips, velocity, channel aftertouch, and a smattering of common MIDI continuous controller options.

Sure, Dave’s previous instruments included a ton of modulation tools also, but what makes the Prophet 12’s implementation so astonishing is the sheer number of audio parameters available per sound. Plus, the modulation runs at audio rates, even with respect to the analog control voltages internally. To say that these patches are dynamic an extremely playable is understatement. In the right hands, this synth can breathe and sing and dance as a musical instrument.

The only thing that the P12 lacks compared to its forebears is a set of step sequencers, which isn’t that big of an issue, considering that you could easily use MIDI over USB to super-fast recreate their functionality from your DAW or even an appropriate iOS app. In fact, I do this all the time over MIDI with my Prophet ’08, using Ableton Live’s clip envelopes over the internal sequencers on the Prophet ’08.


Even though the Prophet 12 lacks step sequencers, it’s still extremely capable in the arpeggiation department. In addition to the expected rate, note value, and octave range parameters, the arpeggiator boasts a repeat function that lets you set whether each note event plays once, twice, or up to four times per arpeggiation step. While the modes are basic—up, down, up/down, random, and assign (the order in which notes were originally played)—the fact that you can have different arpeggiator settings per layer makes the P12 capable of some serious accompaniment functions that border on algorithmic.

Next: Conclusions and original audio examples!


These days it’s fair to divide keyboards into two broad categories: those whose primary jobs include emulating acoustic instruments (ROMplers, workstations, and stage pianos all fit in here), and those that are self-consciously electronic and well, synthy. Three grand may seem like a hefty price for a polysynth in the latter category, but for synthesis fanatics, the Prophet 12 is stellar investment. For starters, it has a sound. It can recreate almost every Prophet ’08 or Mopho x4 patch with ridiculous ease, since it shares much of the same analog technology—like Curtis filters and a real VCA. Then you factor in the new oscillator bank. It’s a bona fide game-changer (we don’t use that term unless we really mean it) that takes this synth to new levels of sound design capability.

Beyond its revolutionary sound, the P12 is a refined performance instrument. With dedicated controls for FM, AM, Shape Mod, and the whole kaboodle, it’s very playable both onstage and in the studio. The sleek touch-strips—in addition to the standard complement of physical controllers—makes this Prophet a soloist’s dream right out of the box.

If you’ve got the cash and really want to stand out from the pack, the Prophet 12 is your ticket. It may or may not make you a rock star, but it will make you feel like a one from the moment you hit your first notes—and that, right there, is priceless.

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