Sequential Prophet X


Despite Dave Smith and Roger Linn apparently being friends, or at least having done a collaboration in the past, DSI/Sequential doesn’t seem to be interested in MPE. The “pro” keyboardist types have been slow to adopt the MPE controllers, with seemingly only a handful investing in something like a Roli.

The Touche is still around - I recall some nice demos w/ the DSI Pro 2. The demos here though are more Moog oriented


This is somewhat understandable.

I recently spend some time with a Seaboard and am now learning to play the LinnStrument I purchased a few weeks ago, and I have to say that both instruments require a completely different technique than playing a standard keyboard.

If you’re an experienced keyboardist, then you’ll have to spend a significant amount of time learning new techniques when you get one of the current MPE controllers.

FWIW, I personally feel that the LinnStrument makes more sense than the Seabord. Sure, the Seaboard will have a more familiar layout, but the techniques you’ll use are sufficiently different that this doesn’t really matter.


Review by Charlie Clouser, the soundtrack god:

Quite a few interesting takes on the sample engine, including FM of a sample; and also on workflow on this thing vs. software.


Clouser is very favorable on the X, in particular how practical it is for music making. Good to read on from this link to Clouser’s next post where he compares the X with the Waldorf Quantum, which he is also favorable to, but for very different reasons. Also interesting are the caveats he offers for both.

I like the idea of “smashing the two together”!


It’s a shame he didn’t ask about MPE. It’s kinda weird DSI is holding out on supporting that.


Indeed. By the time he thought of asking, it was too late.

“- The only thing I forget to ask about was support for MPE / polyphonic aftertouch / etc. If that stuff is implemented correctly, then this thing with a Roli, Linnstrument, McMillen KB4, or Haken could be ridiculous. Squishy sounds controlled from a squishy keyboard - what’s not to love?”


The Prophet X Manual is now available.


I’ve only read a part of the manual – BUT something new to me – the inclusion of single-cycle waveforms (page 107). They are using the ones from the Prophet VS from the 1980’s for now. Looking forward to this being part of the user waveform package that is coming out later in the year as well.

PLUS: The PX is shipping!


Not sure why they’re using the present tense - they make it sound like Dave chose this chip on June 6, the day before the synth ships? I’m imagining the synths sitting in the factory with missing filter chips while everyone waits for Dave to make up his mind, then factory workers scrambling like mad to slap them in before the shipping deadline


Sound Semiconductor was probably under an NDA until the X shipped. So now they get to ‘brag’. This is definitely part of the essence of the X.


Yeah, you’re probably right, but the scrambling elves image in my head is more fun


I realise I’m a bit late to the party, having only just checked this out… But dear lord, the string sounds are incredible. So musical, real and beautiful. The 1920s Steinway sounded lovely too - the different mic’ing options are brilliant.

I’ve never used Kontakt etc… (I’m a hardware guy!) but I’m gonna have to look into it… Maybe there’s a way I could get some of the 8DIO samples in my studio at a price which is a little less brutal! Does anyone here use any of their packs? Is it easy enough to hook up and does it sound as good?


According to the online help person at 8DIO, lots of different samples were re-worked a fair bit for the DSI Seq X. So when it comes to the strings, it’s not as easy as buying the correct sample packs :-/


“Early Impressions” post from another forum by “Lady Gaia”:

Beautifully constructed, this is a build that lives up to expectations set by the price point. The semi-weighted action feels good (1), the ashen stained end caps match the dark metallic aesthetic better than any natural stain possibly could, and in my limited time so far all of the controls have a nice solid feel to them. It is a knobby synthesizer at heart with obvious DSI heritage.

A quick tour is really all I’ve had time for, but there are both standout moments and aspects that I’m going to have to explore deeper before I’m entirely sure what to think. There’s also a lot I need to look at more deeply, including the effects. Essentially all I’ve done is dial in the plate reverb with some percussion and it’s wonderfully stunning. I could have played that kit for hours.

The stereo filters are obviously a centerpiece of the tools at a sound designer’s disposal and they are glorious. Warm and buttery, with resonance that can be subtle or aggressive. I haven’t played with drive much just yet, so that’s also on my list to explore further. In the time I’ve had this evening I have only sped through the first of four banks of presets. There’s a ton here, and so far it’s really wide ranging with more of a tendency toward exuberance than bread and butter.

I should also point out the part I’m least blown away by, which is plain, exposed sample playback. First and foremost, the Prophet X is not going to replace anyone’s modern sampler. This should be obvious from reading the manual, but it’s still something of a shock in practice, and anyone hoping otherwise should adjust their expectations. The samples appear to be well recorded and plentiful, but the lack of any per-sample editing or synthesis parameters means you’re going to use them in a very particular fashion. You can’t tweak a single drum differently than the rest of a drum kit: one pan position/filter/tuning/etc configuration applies to the entire kit. You can’t freely mix and match samples from different keymaps. There’s no overt provision for switching between among keymaps based on velocity, though it’s certainly possible to cross fade between two if desired.

No, it’s not really a sampler. It’s a synthesizer whose oscillators can draw from raw sample material. With that in mind I’m not entirely convinced just yet that the samples offered are the most useful set imaginable. They’re a little specific and literal, drawn as they are from a primarily acoustic library. Still, there’s quite a range on offer and there are definitely a number of unusual ambiances and other textures to explore in addition to the familiar and more exotic acoustic fare.

So it has to come down to doing more than just mixing samples and calling it a day. Finding out just how far you can go with the tools here will be interesting. Those are the terms on which I plan to address the Prophet X and I’m going to need time to dig in that I won’t have much of before the weekend. There are a number of patches I’ve come across that have only oscillators sounding, and they’re still marvelously complex and expressive. Just familiar. So, I’m expecting the real magic is in letting samples and oscillators interact, and that’s where I’m going to be digging deeper.

I wish I could spend more time tonight but, alas, meetings tomorrow morning mandate that I get a reasonable night’s sleep.

(1) I am going to have to explore the velocity curve options because the factory setting appears to have a pretty narrow usable range. It’s easy to produce extremely low and high velocities but the middle of the range takes a unfamiliar touch.

Demos by Lady Gaia:
(deleted due to embedding error - see later post)


Bug in the forum software. Forget about the embedded Soundcloud and go here instead:

Lady Gaia Prophet X Demos (multiple audio files)


There are some really great explorations and experiments here that Lady Gaia did. Really reinforces the reputation for the PX being able to produce good sounds quickly.

I wonder how much the new development that DSI promises by the end of 2018, the support for user samples on the PX, will address Lady Gaia’s point that the PX is not really a sampler?

Does anyone know if the DSI support for user samples will be built into the PX, or is it separate and run on a separate computer? It’s probably on computer.

ADDED: User sample processing is indeed on separate computer.


Nick Batt (of Sonic State) just got the Prophet X for review – looks like he’s playing a little of it live on Sonic Talk 542. Again it shows how easy it is to make ear-grabbing sounds while “playing any notes” (Nick’s words). Yoad loved it immediately.

ADDED: This all may have been in the live feed?


Its hard to get into this synth w/ a 4k price tag. Its not suppose to be for everyone tho, I suppose.


If you don’t have the 4k then use it as an inspiration – think about what you like about it and see how you can capture those elements in things you can afford. That’s why i love “window shopping” – 'cuz it gives some great ideas.

But then again the PX maybe something i want to budget for.


Lady Gaia followed up with a full review:

Overview: It’s About Time

I’m an unabashed fan of digital synthesis. Of course that doesn’t stop me from appreciating classic subtractive analog synthesis, and in particular I adore what a well-designed filter can do for a sound. Still, I’ve been biding my time patiently for the last few decades, waiting for the purist fixation with the analog revival to move on to the stage where we see what modern digital and analog can do together.

Evidently the time is now.

It’s great to see instruments like the Korg Prologue, Waldorf Quantum, and DSI’s Sequential Prophet X taking a shot at creating a modern classic. I had spent quite a bit of time researching the first two, but when DSI made their announcement I placed a pre-order within hours. Roughly six weeks later, serial number 40 arrived, and I’ve been enjoying exploring it ever since.

There’s no denying that it’s an expensive piece of kit, but the exquisite construction and feature set match the price. The highlights are clear enough:

Voices consist of two DSP-sourced oscillators paired with two sampled “instruments.”
150GB of factory samples from 8Dio installed on the internal SSD, with room for another 50GB of third-party or (eventually) user-provided samples.
Sixteen 24dB/octave analog low pass filters.
Five-octave Fatar keybed with channel aftertouch.
Modulation includes 4 LFOs, 4 envelopes, 28 sources in total routable to 88 destinations through 11 dedicated and 16 fully assignable slots.
True stereo voicing by default, producing eight voices sourced from stereo samples and oscillators individually placed in the stereo image.
Selectable 16-voice mode which reduces oscillators and samples to mono whether or not they’re routed through the filter. Each resulting voice can still be panned freely.

The true stereo signal path from beginning to end is a revelation. There’s so much subtle stereo imaging in many of the samples that they bring a lot of life individually. Still, the eight stereo voice limit can feel limiting, especially when stacking two layers or splitting the keyboard where each layer is reduced to 4-voice polyphony. The 16-voice mode is therefore a nice option to have a dedicated button for, lit when active. Better yet, the current state is saved when storing a preset.

Above All: Usability

One of the primary reasons I was looking for a new instrument was immediacy of interface. Having a dedicated array of controls and little or no menu diving was a huge draw, and the Prophet X does not disappoint in this regard.

The interface will be largely familiar to anyone who has used a DSI keyboard recently. Fifty six knobs and fifty buttons (many of which light to indicate status) provide direct access to a wide range of parameters. It’s quick and easy to make changes, and while doing so one of the three OLED screen reflects what’s going on immediately.

Effects and sample selection have their own dedicated screens next to the relevant controls, but everything else uses the larger central display. When a change is made (or a parameter is shown by holding or pressing the show button before touching a control) the display will show the affected parameter and additional related values that can be further manipulated with four soft knobs and four soft buttons. This is a great way to get to extra depth without menu diving: envelope looping or delay stages, configuring oscillators to run freely or reset on keypress, sample rate decimation and bit crushing are all available in this manner.

It’s a joy to use, well thought out from start to finish, but it isn’t as deep or as flexible as a classic workstation. More on that later.

8Dio Samples

Part of the early buzz regarding the Prophet X is attached to the origin of the factory samples. These are culled from 8Dio’s extensive collection and cover a lot of sonic territory. They’re arranged in seventeen categories, each offering multiple keymaps:12 in Ambiance, 52 in Bass, 95 in Brass, 94 in Choir, 56 in Cinematic, 14 in Drums, 18 in Effects, 34 in Ethnic, 41 in Guitar, 66 in Keyboard, 33 in Percussion, another 74 specifically for Tonal Percussion, 39 in Piano, 97 in Strings, 37 in Synth, 35 in Solo Vox, and 61 in Winds. Whew. 841 keymaps in total with each mapping multiple samples across the keyboard, frequently with multiple samples per key selected by velocity range or rotated through in round-robin fashion on subsequent triggering to provide some natural variety. More than 200,000 individual samples at 48kHz, largely in stereo.

There is a staggering array of sound available as a result, but also a lot of overlap. 8Dio is known for their “deep sampling” approach and it’s on display here. Many takes were recorded from multiple microphone positions and so there are frequently two or more keymaps of the same sound taken from near and far microphones and, in the case of the piano, also from the player’s position. There are also multiple playing styles represented including short notes on many instruments and ensemble swells of orchestral staples. So there’s good variety but perhaps not as much as you might think at first. The far samples tend to have a lot of ambiance baked in, and I would have traded all of them for something else entirely.

Some of the keymaps offer an array of different textures on different keys. For example, one has a Prophet VS waveform per key. Several others have an array of ambient textures. Still more have special effects or acoustic instrument miscellany like a trumpet fall or flute trill. These maps aren’t generally intended to be used as-is but in conjunction with Sample Stretch. Just hold down the key that triggers a sample you like, press the Sample Stretch button, and it’s now pitched across the entire keyboard.

Most of the samples are stellar with some disappointing exceptions. The pianos in particular were not to my taste. They tend toward dark, moody, muted recordings, especially at lower velocities. While they’re not going to cut through a mix they do blend in well with other sounds and honestly, that’s really the whole point. All the sample material serves well when you combine it with synthetic sounds and apply modulation subtly or aggressively. Samples make fascinating sources for amplitude or frequency modulation of oscillators - and vice versa.

Sample looping can also be modulated, but while I’ve heard some presets that do this to good effect I haven’t had much success. There are clever looping modes that ensure pitched samples stay in tune, or to take rhythmic content and set the loop length based on MIDI clock tempo. These work great, with adjustable cross fading at the loop point doing its job. Where things get unacceptably click-y is when I’ve tried to modulate a short loop to create something akin to wavetable movement or granular synthesis. Perhaps there are other tricks to learn, or maybe I just need to feed it sample material intended specially for the purpose. Right now, though, all I’ve got to work with are factory samples.

That’s because user sample support is due to arrive in December 2018. DSI has stated that the Prophet X firmware can already load new samples, but that it will take time to finish the Mac and PC software used to prepare keymaps from collections of raw samples. In the meantime, 8Dio is in the unique position of being able to offer aftermarket samples. They had originally planned to do so at launch but have pushed the two announced packs back to August. One nice touch is that in addition to four banks of factory presets (512 in total), and an equivalent number of user slots, there are another four add-on banks reserved for programs that showcase newly added sample content.

One incredibly pleasant surprise is just how fast everything loads. Each keymap can have a maximum of 1.5GB of associated samples, so a program with two layers can require as much as 6GB to be loaded into RAM from the internal SSD. In practice they load quickly enough that I’ve never felt like I was waiting. Likewise, switching among keymaps while editing a program feels essentially instantaneous. Impressive, though I’m sure in part it’s due to the fact that most keymaps are actually much smaller than the maximum.


The are two DSP derived oscillators per voice, and they’re doubtless a derivative of past DSI synthesizers that forgo analog oscillators like the Pro 2 and Prophet 12. They’re limited to square, saw, sine, and supersaw shapes. Reviewing their output in an oscilloscope reveals a subtle second harmonic that doubtless counters what might otherwise be an aggressively digital sound. This additional harmonic on the sine and saw can be emphasized with a shaping parameter that can be modulated in real time. With the supersaw the second harmonic starts out prominent and the shaping appears to adjust how detuned it is. On the square wave the shaping parameter adjusts pulse width, and can erase the pulse completely at extremes.

There’s a selectable amount of slop as a dedicated control to allow the tuning of the oscillators to drift, along with a hard sync button. Additional parameters without dedicated controls switch between free-running and resetting when a voice is triggered, along with a selectable phase when oscillators are reset.

No white noise or sub-oscillators are present, but the sampled instruments are more than capable of filling this gap with a wide range of noise types, waves from the classic Prophet VS, even sampled ensembles of analog synthesizers playing conventional oscillator shapes.

Those Sweet Filters

The filters bring a wonderfully smooth, warm character to the Prophet X sound that is a clear defining characteristic. The lack of a 12dB/octave option is offset by the care that has been lavished on this single slope design. Resonance can be used to restore a little edge and can be driven to self-oscillation. There’s also a selectable (and modulatable) drive parameter that can add some overdrive grit. I found something to like about every aspect of the filter.

These are modern recreations of the classic SSM2044 immortalized in synthesizers ranging from the PPG Wave 2.3 to the Korg Monopoly, Polysix and Trident. The new SSI2144 has lower noise and other key improvement while retaining the sonic character of the original, in part because Dave Rossum is back to improve on his original design.

There’s a dedicated filter envelope and many more modulation options are available. The cutoff of the left and right channels can be modulated independently, for example, and applying modulation to drive or resonance opens up a lot of possibilities. Audio rate filter modulation leads to some extreme options I’ve only begun to explore.

On a per-instrument basis sample keymaps can also bypass the filter entirely if desired.


The effects section is fairly basic, but perfectly capable of adding either character or ambiance. Each layer has two effects in series, selectable from a list that includes delays (BBD and clean stereo), Leslie simulation, reverbs (spring, room, hall, and “super plate”), chorus / phaser / flanger, as well as distortion and a high pass filter. Wet/dry mix and three other parameters are immediately available from the front panel and can be modulated.

The super plate reverb is an impressive standout, capable of long smooth tails, continuously adjustable dark or bright character. Paired with a percussive sound it’s easy to get lost here – but it’s also something you’re likely to turn off for recording. Defeating the effects is trivial, with two dedicated buttons that illuminate to show when each effect is active.

Not a Workstation

Yes, samples are a significant part of the instrument but no, this isn’t your next workstation. For starters, it’s only bi-timbral. Each preset consists of two independent layers that can be played one at a time, split at a selectable key, or layered. When split or layered, half the instrument’s polyphony is allocated to a layer. That means a monophonic bass in a split configuration still limits the right hand part to four notes.

There is a global setting to enable Multi Mode where two layers are fully addressable on two distinct MIDI channels. This even allows program changes to load unrelated A and B layers rather than the usual pairing, but it’s a far cry from a sixteen channel multitimbral setup with dynamic voice allocation you’d find in a classic workstation.

DSI’s dedication to making an easy to approach instrument also limits the depth of editing available. Keymaps are pre-baked arrangements with key assignment and velocity mapping baked in. There’s no provision for reassigning samples to different keys, which would be handy for drums kits, nor can you mix-and-match samples from different keymaps to create velocity switching from a smooth bass to slapping techniques. Either it’s designed in, or it isn’t.

The same kind of simplicity applies to all of the synthesis options at your disposal. Want to subtly reinforce your bass drum with a sine wave oscillator? Great! Hope you like it on your cymbals, too, because it applies to the entire layer. Likewise for filtering, which would have been wonderful to tweak per-drum. You can adjust keytracking, but that’s the extent of your control.

So no, it’s not a workstation. It’s a wonderfully immediate performance synthesizer, and if you approach it on those terms it isn’t likely to disappoint.

Strengths and Weaknesses

I’ve been pleasantly surprised by the array of fresh-feeling modern sounds packed into the Prophet X. It’s easy to get around, seems to strike a healthy middle ground between purely experimental and usable when it comes to presets, and there’s a lot of promise in expanded potential as new sound banks and user samples make their appearance. In short, it’s the blend of classic subtractive and sample-based synthesis I’ve been waiting for.

Polyphony and programming depth can feel like constraints easily enough, but they can also be helpful by focusing on creative use of the tools that are present. The 512 factory presets explore a lot of territory without getting redundant. They also lean toward exuberant sonic territory with lots of modulation options. There are a few bread and butter sounds, but they’re in the distinct minority, overshadowed by showier fare.

If you have a chance to try the instrument out or purchase one, don’t forget that every preset comes with a pre-programmed sequence using DSI’s basic step sequencer. These can be a good way to hear what the sound designer had in mind. Presets that don’t come up in stacked or split mode also have a “layer B” that’s worth trying out. Most of them are interesting variations on the base sound.

Shout-Out re: Responsive Support

I had concerns initially about quirks with one of the display showing visual corruption, and also the response of rotary encoders used as soft knob above the central display which would frequently skip values.

Both were addressed with software updates in just a few days after I reported them to DSI support. I am beyond impressed and satisfied that I’ll be treated equally well should any other problems arise with my purchase.


I like it a lot. Highly recommend for anyone who sees intriguing potential in hybrid digital / analog synthesis, but don’t expect it to replace the rest of your gear.