A legendary synth designer delivers a new classic
DSI’s Prophet 12 combines digital oscillators with analog filters and amplifiers in a roadworthy package. Red backlighting will help gearheads identify it from way offstage.WHENEVER ANYONE mentions the Prophet 12, all of the musicians in the room adopt an almost reverential tone. From the moment synth pioneer Dave Smith appeared in an online video showing off its capabilities and sound last January, practically everyone agreed it was destined to become the most desirable new synth on the planet. Now that it’s shipping, does it live up to expectations?
First Impressions Count The P12 features 12-voice polyphony, as its name suggests, and two independent timbres per Program (Layer A and Layer B). Each voice is an analog/ digital hybrid. All the oscillators are digital, but the voltage-controlled filters, the voltage- controlled amplifier (VCA), and some of the effects are entirely analog. Other notable features include a versatile arpeggiator and an unusual effect borrowed from the DSI Evolver called “tuned feedback.”
The P12’s build quality is solid enough that it should easily withstand the rigors of the road if treated with respect. The velocity- sensitive keyboard offers channel Aftertouch and a snappy unweighted action.
Although you can read the OLED graphical display from any reasonable angle, I wish it was twice as big. Fortunately, it’s extremely clear, bright, and easy to read, though much of the type is small. Four buttons below the display select parameters that appear there, and four rotary encoders above it affect their values.
Dedicated knobs and buttons on the front panel access most functions. When you turn or press almost any control, the display reveals its associated parameters and values. If you press the Show button, you don’t have to change a parameter to see its value. That kind of visual feedback makes it easy to grasp exactly what’s going on at any time.
The Modulation section has just two buttons—one to assign sources and another to assign destinations—and a bipolar knob to adjust the amount. Because everything you need to know appears in the display, modulation routing is as clear and straightforward as I’ve seen on any synth.
The touch sliders are sensitive to finger position (indicated by an LED ladder) and pressure, providing a total of four latchable modulation sources you can route to any destination.
The two footpedal jacks on the back double as CV inputs: Use them to control volume, filter sweep, and other pedal-type parameters, or configure the modulation matrix to control any mod destination using a CV source.
Tracing the Signal Path Some of the effects and all of the oscillators, filters, and VCAs are monophonic, and they stay monophonic until they reach the stereo output stage. Nonetheless, the P12 sounds gorgeous, thanks to plenty of oscillators, well-designed filters, extensive modulation capabilities, and stereo delay combined with other effects.
Each voice has four audio oscillators and a sine-wave suboscillator. You get four analog- style waveforms, a dozen more-complex digital waveforms (with names like Nasal, Gothic, and Buzzzz), and three flavors of noise (white, red, and violet). The four oscillator buttons are arranged in a circle representing how they connect when they’re synced or modulating one another using FM or AM. A Slop parameter makes the oscillators sound more analog by randomly detuning them as much or as little as you want.
The Shape Mod/Pulse Width knob changes the symmetry of pulse, sawtooth, and triangle waves and adds harmonics to sine waves. It brings digital waveforms to life by scanning between any three you select to make up a wavetable. The knob’s center position chooses the first waveform; turning it clockwise or counterclockwise results in different spectra, and you can view the waveshape in the display as you change it. Applying any modulation source multiplies your chances of adding motion to your sounds.
The 4-pole button lets you toggle the Curtis-based lowpass filter between 12dB- and 24dB-per-octave slopes. The lowpass self-oscillates only in 4-pole mode and has a dedicated envelope generator. Because you can modulate the resonant highpass filter, you can create highpass sweeps independent of the lowpass. For bandpass filtering, the two filters are arranged in series.
Four DADSR envelope generators and four LFOs provide plenty of opportunities for automated modulation. The LFOs are especially versatile, with settings for waveform, phase, and slew rate, which reshapes waves by smoothing their edges. Although two of the envelopes are devoted to the lowpass filter and VCA, you can route control signals from any envelope to any modulation destination. The filter and VCA envelopes can loop their delay, attack, and decay segments for as long as a note is held.
Eight fixed modulation routings let you assign all the LFOs and envelopes to control any of 97 destinations. Sixteen additional routings let you freely assign any of the 26 mod sources to any destination, which may include individual envelope segments, lowpass or highpass resonance, delay time, character depth, or feedback tuning.
One with Effects Each voice has a 4-tap stereo delay that can sync to the arpeggiator, mod sources, or MIDI Clock. Use the Delay section’s Time, Amount, and Feedback knobs to create echoes as long as a second, to simulate reverb, or to program chorus and flanging effects using shorter delays. Surprisingly, you can’t save or recall delay settings as separate presets; you can only save them as part of a program.
Thanks to the P12’s tuned feedback, guitarists aren’t the only players who can make their axes howl. Each voice’s VCA output is routed back to an internal input and mixed with the oscillators to create a feedback loop. You select the amount of either positive or negative gain and set the loop’s initial frequency, which is quantized by semitones over a 4-octave range. And because tuned feedback always tracks the keyboard, you can play the feedback melodically.
The back panel includes four unbalanced 1/4-inch outputs, one footswitch and two pedal inputs, MIDI I/O, and USB. The main outputs carry both layers, but when you plug into the second pair of outputs, each pair carries a separate layer. Each of the Character section’s effects has a single knob for controlling depth. Girth is a low-shelf filter (for bass boost), and Air is a high-shelf filter (for treble boost). Drive is a variable distortion for each voice. To really dirty up your sound, Decimation reduces the digital sampling rate, and Hack reduces the bit depth. A separate Distortion knob near the volume control affects the entire mix.
Timbral Powerhouse The P12 stores 792 programs in eight banks of 99 programs each. Four factory banks are etched in stone, and four user banks are rewriteable. The numeric keypad lets you instantly access any program.
Programs containing two timbres can be split or layered, or you can select one at a time. When programs are split, you get six voices from the right side and six from the left. When they’re layered, you get voices in stereo and 6-note polyphony. You can’t specify how voices are allocated.
Although the P12 delivers screaming leads, thundering basses, ethereal atmospheres, and in-the-pocket arpeggios, a number of the factory programs don’t take full advantage of the realtime controllers. Very few respond to Aftertouch, for example. Fortunately, it’s easy to customize modulation routings to suit your preferences.
I’ll Take 12 Combining some of the best ideas from the Prophet ’08 and Evolver series, the P12 transports the Prophet concept firmly into the future, making it an instant classic. For my money, it’s the one hardware synth introduced in 2013 that’s most worth having.
DSI deserves praise for incorporating touches such as tuned feedback, an extensive modulation matrix, and a user interface that makes complex patches easy to grasp. If fabricating timbres that steer clear of acoustic sounds appeals to you (it certainly does to me), try the Prophet 12 and decide for yourself whether it lives up to its reputation.
STRENGTHS: Brilliant user interface. Impressive modulation capabilities. Excellent analog filters. Full-featured arpeggiator. Multitap delay. Tuned feedback. MIDI over USB.
LIMITATIONS: Monophonic signal path. Two-part multitimbral. Receives on only one MIDI channel at a time. Stereo voices reduce polyphony to six notes. Can’t allocate voices per layer.
Geary Yelton was an editor at Electronic Musician for ten years. His first book, The Rock Synthesizer Manual, was published in 1983.