Review: Rob Papen eXplorer III

A synth and effects suite that stands out from the pack.
Publish date:
Social count:
A synth and effects suite that stands out from the pack.
Image placeholder title

Dutch software developer Rob Papen and company have long enjoyed a reputation for top-notch soft synths, effects processors, and designer sounds. Since 2011, they’ve offered a comprehensive collection of their plug-ins in a bundle. Now in its third incarnation, eXplorer III encompasses eight virtual instruments and six effects processors for less than half what you’d pay if you purchased them separately.


Blue II: Introduced last year, the latest version of Papen’s best-selling synth combines four synthesis engines—subtractive, waveshaping, FM, and phase distortion. Sounds begin with six oscillators, each with more than 300 algorithmic and sampled waveforms, routed through two stereo multimode filters. Tailor your timbres by editing AHDSR and multistage envelopes, configuring FM algorithms, and routing modulators.

In addition to note sequencing, Blue II’s 16-step sequencer lets you assign different waveforms (for wave sequencing) and modulation values (for mod sequencing) to each step. Access an x/y pad for panning between oscillators (for vector synthesis) or manipulating as many as eight parameters simultaneously. What’s more, Blue II’s preset library serves up some of the best sounds you’ll find in eXplorer III.

Blade: If Klingons designed a soft synth, it might look like Blade, an additive soft synth with an innovative, streamlined approach to building waveforms. Instead of specifying individual harmonics, Blade’s Harmolator lets you turn knobs to determine the fundamental, number of partials, balance of harmonic and inharmonic partials, and so on. You’ll instantly hear your results and view them in a spectrum display.

Alongside the synthesis sections, Blade’s GUI is dominated by an x/y pad surrounded by 24 knobs that duplicate the Harmolator’s knobs on both axes (see Figure 1). Clicking and dragging on the pad twists the knobs to dynamically manipulate harmonic content in real time. You can record and play back your movements in a loop that you can sync to tempo. Blade also has flexible modulation routing, an arpeggiator with step-sequencer functions, a respectable assortment of effects, and hundreds of presets designed to show off its capabilities.


Punch: This unusually deep virtual drum machine generates percussive timbres both by synthesizing them and by playing samples. Its synthesis capabilities go far beyond what you might expect, and you can even import your own samples.

Create and edit individual sounds in meticulous detail, process them with effects, assemble them into kits, and build patterns using the 16-step pattern sequencer. Some notes on your MIDI keyboard trigger individual hits, and others trigger as many as eight grooves or breaks that can play simultaneously. Punch gives you a tremendous library of factory presets that supply hits, grooves, and breaks for any genre.

Punch-BD: If you want thick, fat bass drums, it helps to stack your sounds, and Punch-BD can stack six of them at once. Like Punch, Punch-BD lets you synthesize sounds, use factory samples, or import your own.

Depending on the mode you select, hits can be stacked, played individually, played sequentially, and so on. Although you don’t get an onboard sequencer, presets include hundreds of bass drums, as well as additional drums, percussion, and sound effects.

Raw: Raw specializes in distorted sounds that slice through a mix and tear off your face, making it suitable for experimental, metal, EDM, and other cutting-edge musical genres. Although its content includes some lovely pads as well, Raw has a low-fi personality all its own.

More than anything else, Raw’s two oscillators are what distinguish it from Papen’s other synths. They generate just four basic waveforms and two flavors of noise. You can also draw your own waveforms and save two of them. (Raw’s manual suggests using hand-drawn, low-frequency waveforms to create wobble sounds for dubstep.) Each oscillator has a distortion knob and an x/y pad to dynamically manipulate phase distortion, and Raw will record pad motion synced to tempo. Other features include a waveshaper, a multimode filter, a 16-step sequencing arpeggiator, and 13 flavors of distortion.

SubBoomBass: Want to give your subwoofer a workout? SubBoomBass focuses on primarily electronic bass sounds. It comes with over 1,000 presets that include percussion patterns as well as basses. Two oscillators let you choose from 14 single-cycle waveforms, white and pink noise, 10 electric and acoustic bass samples, and 39 drum and percussion samples. Each oscillator is paired with a suboscillator, and many presets layer drum samples with basses to reinforce the bottom end.

SubBoomBass’s 16-step sequencer can trigger the two oscillators independently with a different waveform for each step (for wave sequencing, again). You can tie steps and slide between them, TB-303-style. There’s also a stereo multimode filter, an additional lowpass/highpass filter, three 5-stage envelopes, extensive modulation routing, and a full complement of effects.


RG: RG’s onboard step-sequencer operates much like a drum machine, but you program rhythm guitar patterns rather than drums by entering and editing individual up, down, and ghost strokes. Modify the sounds of six sampled guitars using three simultaneous effects and a host of synthesis parameters. Hundreds of presets cover many styles of music.

For playback, RG divides your keyboard into four ranges. The first octave plays a pattern using major chords, and the next plays the same pattern using minor chords. The two higher octaves play a different pattern using major and minor chords, respectively. Even if you don’t use RG on your finished track, it could suggest rhythmic ideas that inspire new parts or new ways to approach a composition.

Predator: Predator is a deep but straightforward subtractive synthesizer with three oscillators that generate dozens of single-cycle waveforms. Its sophisticated arpeggiator doubles as a 16-step sequencer, and you can trigger strummed chords with a single key. You also get two multimode filters, four 5-stage envelopes, six LFOs, and eight assignable modulation routings.

Predator’s best trick is creating new sounds by combining characteristics of existing presets. In the Morphing section, simply choose two presets, set the amount, click the Gen button to generate something new, and keep clicking until you hear something you like. I was surprised by how good some of the results sounded. A similar function called Variations creates new sounds from a single preset. Perhaps the best reason to own Predator, though, is its tremendous collection of more than 4,400 presets, with more available online.


PredatorFX: Predator comes with a separate plug-in that lets you process audio from any source using Predator’s effects and filters. It features not only favorites like delays, reverbs, choruses, and amp simulators, but also a 32-band vocoder.

RP-Delay: This versatile plug-in comprises two stereo signal pathways, each with three independent delays that can route signals in various configurations. Each pathway provides four LFOs, four multimode filters, four 16-step sequencers, and assorted modulation sources for continuously controlling user parameters. RP-Delay can even play segments of audio in reverse.

RP-Verb: Papen’s smooth algorithmic reverb has presets tailored for vocals and instruments, as well as variations that mangle sound beyond recognition. In addition to controlling the type and size of the space being simulated and parameters that affect early and late reflections, it can simulate different reflective materials. You also get simple distortion, 3-band EQ, and a three-stage envelope that modulates the volume, size, and length of the reverb.

RP-Distort: With four LFOs and MIDI inputs for controlling parameters, RP-Distort delivers 26 effects types such as clipping, fuzz, ring modulation, speaker-cabinet simulation, and even distortion based on trigonometry. You can use the plugin’s distortion, compressor, filter, and stereo-field enhancer either individually or in any combination and in any order.


RP-AMod: Specializing in chorus, flanging, phase-shifting, ensemble, and tremolo, RP-Amod can process high and low frequencies separately, and all effects can sync to tempo. Presets load two simultaneous effects that work in tandem for vocals, instruments, and multipurpose special effects. The control panel provides a choice of modulation waveforms and from five to eight user parameters appropriate to the selected effects type.

Fig. 2. RP-EQ’s mono/stereo split filter lets you apply processing to lower and higher frequencies separately, and the Air section offers a wide additional band with a center frequency between 30 and 40 kHz.RP-EQ: This 8-band equalizer is designed for a variety of mixing and mastering applications. Change frequency, gain, and bandwidth by clicking and dragging on the display or by adjusting knobs. Use the x/y pad to dynamically control most parameters and record your movements, or toggle to a spectrum analyzer that displays input or output signals as lines, bars, or peak indicators.

Image placeholder title

RP-EQ’s mono/stereo split filter divides the signal into mono low-frequency and stereo higher- frequency signals (see Figure 2). The equalizer can switch between normal and mid-side mode. You also get lowpass and highpass filters, simulated tape saturation, and an Air section to expand the top end.


Wonderful assortment of virtual instruments and effects processors. Nice variety of sound engines. Impressive programming depth. Plenty of bang for the buck.


Not all sounds may suit your musical tastes.

upgrade from any Rob Papen product: $499 upgrade from three or more products: $199

Synthesist and former senior editor Geary Yelton has written for Electronic Musician since 1985.