Master Class: Dave Smith Instruments Prophet X - EMusician

Master Class: Dave Smith Instruments Prophet X

Programming tips for the ultimate hybrid synth/sample player
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In just 10 years, Dave Smith Instruments has released examples of true analog, advanced digital synthesis, two DCO-based hybrid synths, and a powerhouse drum machine collaboration with Roger Linn—along with a slew of more affordable products that slide into almost any budget. While everyone pondered, “What’s left?” Dave revived a few elements from his groundbreaking Prophet 2000, packed it with 150 gigabytes of top notch multi-sampled instruments, and folded in his trademark filter and modulation tools, creating a synth that’s much more than a workstation ROMpler. The Prophet X is a new breed of hardware synth.

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Having worked with the Prophet X for much of the spring as a member of the preset design team, this tutorial will cover many of the insights I’ve gleaned about its deep synthesis engine, which offers far more than just sample playback with a bunch of synthesis tools.

ARCHITECTURE

In addition to two sample-based oscillators, the Prophet X includes a pair of digital oscillators that offer four options—saw, square/pulse, supersaw and, interestingly, sine, which is tremendously useful in this particular context. The oscillators feed true analog filters with some unusual and relevant routing options. From there, the VCA’s output feeds a pair of effects similar to those found across the line of DSI’s newest synths.

On the modulation side, the Prophet X evokes the Rev2, with four LFOs, four envelopes and extensive MIDI performance controls that include innovative touch sliders—ideal for morphing applications when used with multiple parameters. Additional amenities include two-way splits and layers, along with the same arpeggiator and step-sequencer you’ll find in the company’s most recent synths.

SAMPLED OSCILLATORS

In approaching the Prophet X, the first thing to do is familiarize yourself with the diversity of instruments in the sample-based oscillators. There are 17 instrument categories, with up to 99 discrete multi-sampled instruments for each (depending on the category) created by soundware developer 8DIO.

The front-panel controls include dedicated knobs for start point, end point, loop size and loop center, as well as switches for reverse and loop on/off (see Figure 1). Having these parameters at your fingertips is a very different experience than the usual software approach and invites experimentation. But to access some of the instrument’s most innovative aspects, you will need to dig into the menus a bit.

Fig. 1

Fig. 1

With so many instruments available, designing sounds with these samples really becomes a matter of taste. On one hand, you can instantly create classic layers such as strings/piano, Roland D-50-like bell-pads, and massive orchestral combos with just a few knob twists. Experienced users will want to experiment with the more sophisticated features, which include possibilities that no other hardware synth currently offers. As you explore the more complex editing features, here are some areas worth closer inspection.

Sample Start: To some this is a no-brainer, but for others it’s a parameter to get a handle on, as it is a crucial element for many of the rich orchestral instruments that include realistic bowed or blown attacks. For example, if you want to make a percussive sound based on a string orchestra or flute, their nuanced attacks could make this problematic. In that case, advance the start point to an area past the acoustic attack and the sound will begin instantly. Alternately, you can use this parameter to soften the hard transients of percussive and plucked samples.

Sample End: The Roland D-50 included many very short transient samples for layering with its other elements. Setting the end point very close to the attack audio segment can replicate this behavior.

Sample Reverse: There are many reasons to reverse samples of acoustic instruments like piano and guitar, but the Prophet X also includes a vast collection of sung operatic words (such as “Liberis” and “Gloria”) both in solo and choir formats, many of which are quite long.

In some cases, those may be a tad too highbrow for pop or dance productions, so hit the reverse button and subtract the linguistic content while retaining the timbral component. You may lose the loop, but you can then design your own at that point.

Loop Editing: The front panel’s loop Size and Center controls make it easy to quickly transform the factory loop points—or add your own loops to shorter sounds. The caveat here is that these parameters work using a base-1000 system, which for some instruments makes finding seamless zero-crossing points arduous. If you encounter issues getting the custom loop you’re after, here are some tricks that should speed things up.

There are three loop modes: Regular, Pitched, and Synced. Regular functions like a classic hardware sampler. Pitched does a fantastic job of intelligently adjusting very short loops so that they remain in key with the original sample. Synced works in conjunction with the global BPM to help find loops that are rhythmically aligned with your tempo.

Pro Tip: If you’re after vintage ROMpler sounds like pianos or mallets with realistic attacks and very short loops, use Pitched mode and set the loop point shortly after the initial attack transient.

Loop crossfading (XFade) is available across all three modes and is great for minimizing any pops, clicks, or irregularities in your custom loops by crossfading the ends and beginnings of loops. The effect is most pronounced in Regular and Synced mode, with subtle smoothing on short loops in pitched mode.

Reversing and looping: For several of my choir presets, I wanted to eliminate any sung words, while retaining the lush realism of the original samples. After reversing the sample—noting that the start and end parameters were also inverted—I isolated the desired section. From there it was a matter of fine-tuning the loop and adjusting the crossfade until the goal was achieved.

Sample Stretch: This is a signature feature of the Prophet X approach to working with sampled material. When playing a sampled instrument, you can hold any key and press Sample Stretch, which then assigns that single sample across the entire keyboard. A common use is to re-create old-school samplers and drum machines (and Ableton’s Simpler) by playing samples far outside their realistic range.

Additionally, the Prophet X includes a wide range of cinematic and ambient samples arranged across the keyboard multi-timbrally. To isolate any of these, select the instrument that contains your desired sample, hit the key, then press Sample Stretch. From there, you can customize it further with the editing tools described above.

Timbral Control: Two simple features let you tailor the timbre of sampled instruments before they reach the mixer (see Figure 2). On the Inst Tune page, the Tone control behaves like a hybrid of shelving EQ and HP/LP filter, allowing frequency-sculpting techniques that are useful for blending samples or unusual tonal effects. On the Inst Misc page, there’s a switch that lets you route the samples to the VCA after the filter, so that the digital oscillators are sculpted but the samples pass through untouched.

Fig. 2

Fig. 2

Pro Tip: Both of these parameters are useful for layering bright percussive instruments over pads or blending strings with a synthesized version for larger than life orchestras.

DIGITAL OSCILLATORS

The dual digital oscillators include classic saw and pulse waves, as well as supersaw and sine options (see Figure 3). Hard-sync is also available for those iconic Prophet-5 “squawk” leads.

Fig. 3

Fig. 3

In addition to adjusting the width of the pulse wave in classic fashion, the Shape knob also affects all waveforms. For supersaw, it’s a depth/detuning knob. On sawtooth and sine, the effect is a spectral shift, with the sine shaping adding a few extra harmonics (see Figure 4). As a result, the shape parameter is a top choice for adding harmonic animation via any of the Prophet X’s extensive array of modulation sources. Obvious choices are LFO and envelope, but the multitude of performance sources—like velocity, aftertouch, and mod wheel—offer the option of adding tonal dynamics to your patches.

Fig. 4

Fig. 4

For those who yearn for real analog oscillators, here’s an easy way to get very close to that sound. The front panel includes a dedicated Slop knob that simulates the note-to-note tuning discrepancies that occur when cycling through voice cards on a vintage polysynth. Additionally, each oscillator’s shape page includes its own Wave Reset parameter that causes the waveform to start from the same phase point with each key event (see Figure 5). Turn it off and the oscillators will cycle freely, regardless of whether a key is pressed, just like a proper analog synth. By turning off Wave Reset and adding a Slop amount below 25, you can quickly re-create many of the idio-syncrasies of an older instrument.

Fig. 5

Fig. 5

Dave Smith’s choice of a sine wave instead of the expected triangle wave is a stroke of genius because this waveform works beautifully with sampled material, as well as serving as an audio-rate source in the unit’s modulation matrix (covered below).

Here are four handy uses for the simplest of waveforms:

For instruments without a strong 1st harmonic—or mallet/bell sounds with numerous inharmonic frequencies—tune the sine wave to the same pitch as the sample, then blend their mix according to how much you want to emphasize the fundamental.

Tuning the sine wave an octave lower is an expedient tactic for adding bass frequencies that track the pitch of your riff, much like an extremely precise EQ that you can then control via the mixer.

Setting one or both sine waves to higher frequencies will add shimmer and presence to some types of sampled instruments. Alternately, tuning these high frequencies to odd intervals or applying extreme detuning can increase the bell-like characteristics of an instrument.

Using a single sine wave in lower octaves with the filter open is a quick and easy method to instantly create a trap or hip-hop bass.

MIXER

The four sample and oscillator Level knobs only reveal part of the picture. Touching any of them brings up the mixer screen, which offers panning for each oscillator and also includes the Prophet 12’s Hack and Decimate (bit-crushing) effect (see Figure 6).

Fig. 6

Fig. 6

Pro Tip: Because the mixer is positioned before the filter, lowering the cutoff will smooth some of the digital “graininess” that comes with higher bit-crushing values.

FILTER

The Prophet X’s filter is a custom 24 dB lowpass circuit with front panel controls for Cutoff, Resonance, Drive, and Keyboard Tracking, as well as its own dedicated envelope with knobs. Digging a little further into the LPF Misc page, you’ll find a Stereo Split parameter with positive and negative values (see Figure 7). This dual filter makes perfect sense as many of the instrument samples are stereo and the mixer offers panning for the oscillators and samples.

Fig. 7

Fig. 7

At first listen, turning the Stereo Split knob appears to be a panning effect, but what’s actually going on is the cutoff for one side is lowered as the other is increased. If you really want to hear what’s going on with this effect, raise the resonance to around 75%, lower the cutoff to 40-50%, and sweep the Stereo Split parameter. With a saw-tooth, the result will be a formant-like sweep due to the dual resonant peaks. What’s more, the filters can be independently modulated by any source in the matrix.

MODULATION MATRIX

The Prophet X modulation matrix offers 16 freely assignable and 11 fixed sources that directly correspond to the LFOs, envelopes, velocity, and so on (see Figure 8). While you can edit these in the main screen, there’s an easier way to get the job done.

Fig. 8

Fig. 8

For the fixed sources, you can instantly assign any LFO to almost any front panel parameter by pressing the associated LFO button and twisting the desired knob. Envelopes 3 and 4 also work in this manner. For sources like the mod wheel and sliders, shift your attention to the minimal Modulation area on the front panel and hold the Assign Source button while moving the mod wheel or other controller (see Figure 9). Next, hold the Assign Destination button and turn the knob you want to modulate. This also works with the effect parameters, incidentally, which is huge for controlling reverb dimensions from the sliders—a favorite design trick of mine.

Fig. 9

Fig. 9

While the classic routings are fairly self-evident, deeper parameters require some menu diving. For example, either of the oscillators and the sampled instruments will work as audio rate modulation sources. This is huge, because you can assign them to things like oscillator frequency (FM), any of the mixer channels (for amplitude modulation or pseudo ring modulation), panning, or the filter’s cutoff frequency to create effects that are normally the domain of sophisticated modular setups. Noise is also available as a modulation source if you like dirtier sounds.

Not so obvious is the ability to assign the modulation depth of any of the 16 routings as a destination. A classic application for this is to allow performance controls (mod wheel, velocity) to affect the things like LFO modulation depth, but the design possibilities are nearly limitless.

For example, you can assign modulation slot 4 with oscillator 2 modulating panning at audio rates, but with a depth of zero. From there, assign that modulation 4 routing as the destination of LFO 2 and use the LFO to sweep the depth of the osc 2 audio-rate modulation—synced to tempo.

To go even further, add another modulation routing so that one of the touch faders or keyboard tracking changes the depth of that effect as a performance element. Getting it all sorted requires forethought, but the results are well worth the effort.

Pro Tip: Amplitude modulation remains fairly uncharted synthesis territory. To begin experimenting with this underrated technique, use one of the sampled waves to modulate the amplitude, panning, or waveshape of one of the digital oscillators. From there, dial through the various instruments to hear the range of possibilities.

Another radical Prophet X feature is the ability to modulate the primary sample editing parameters: Start, End, Size, and Center. Size and Center are especially useful for clever glitch effects on looped material, while modulating the Start parameter with velocity or slider is handy for adding character to live playing. This is definitely an area where experimentation is key, as every instrument has its own personality and these features are unprecedented in a modern hardware synth.

EFFECTS

The dual effects cover all of the usual bases—chorusing, flanging, reverb, delay, and phaser, among others—with controls for mix and three essential parameters (see Figure 10). While the majority of these effects will already be familiar to many users, here are a few tricks you can do that may not be immediately apparent.

Fig. 10

Fig. 10

1. Fans of vintage string-machines should look to the flanger, not the chorus for emulating their classic ensemble sound. Here, set the mix to 50:50, rate between 40-90, depth higher than 50 and feedback lower than 150. For added thickness, add a tiny bit of chorus to the second effect and lightly mix that in.

2. While the filter is strictly lowpass, there is a highpass (HP Filter) option in the effects. For a conventional effect, make sure the mix is set to maximum, otherwise you’ll hear the dry signal. In performance, try routing one of the sliders or the mod wheel to control cutoff or automate it for production purposes.

Pro Tip: Since the highpass filter cutoff can be modulated with an envelope using the modulation matrix, it’s possible to use it paraphonically.

3. The Prophet X has a wonderful collection of guitar samples, so experiment with the distortion effect to create metal and grunge sounds. Before you begin, set the level (FX parameter 3) to 70 or less, so you don’t blow your ears off. Then set the mix to 127 and gain to 255. At that point, tinker with the Tone and Gain knobs to dial in a variety of amps and pedal effects. For added realism, put the spring reverb effect after this.

4. All of the Prophet X reverbs sound terrific, but the Super Plate has a special place in my heart. It’s extremely smooth and you can modulate the pre-delay with a tiny bit of triangle LFO and achieve a nifty vibrato/chorus with it (or get radical with larger amounts and unconventional waveforms).

The Prophet X also includes a new Leslie-like Rotating Speaker effect. Although this is an important processor for players who use tone-wheel organ sounds, it can also be added to other instrument patches to further stir things up.