Review: Wolfgang Palm PPG Infinite Pro

The inventor of wavetable synthesis pulls us farther down the rabbit hole
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Wolfgang Palm’s synthesizers have never been like other synths. By 1980, the year he launched the PPG Wave, he had already designed and built some of the earliest digital instruments you could buy. The Wave was the first to harness wavetable synthesis, a technique that is now more popular than ever.

Wavetable synthesis divides sounds into lists, or tables, of individual waveforms. A sort of virtual play-head, or cursor, scans through these lists during playback. By controlling playback position as the cursor moves forward or back through a list, you control the timbre being produced at any given moment.

Palm was also the first serious synth designer to create a sophisticated wavetable synth for the iPad, including PPG WaveMapper, WaveGenerator, and Phoneme, each exploring different variations on wavetable synthesis, as well as Infinite, an additive synth app.

Infinite Pro, a more advanced version of the Infinite iPad app, is a VST and AU plug-in for Windows and Mac OS. It supplies a sizable collection of spectral profiles called Sine Resources and Noise Resources, and you can import or create your own, as well. Most resources are extracted from sounds that have been sampled, analyzed, and resynthesized as sine waves, while others have been digitally generated and manually edited. Playing Infinite Pro most often involves combining resources, scanning through their constituent components, and modulating them with one another.

Infinite Pro’s raison d’être is to create sounds with unprecedented control over harmonic content. It gives you the ability to split up any sound into its constituent overtones, either harmonic or inharmonic, and control each overtone’s changes in frequency, amplitude, and phase from the moment of its attack until its final decay.

This capability resembles the behavior of acoustic sounds in the real world. A piano tone’s harmonics, for example, do not remain fixed as they progress in time. They are constantly shifting as their relative strengths and frequencies change, no matter how slightly, which helps our ears distinguish one sound from another and judge the quality of those sounds.

Most synthesizer oscillators, even traditional wavetable oscillators, produce sounds whose harmonics have fixed frequencies, and Infinite Pro goes beyond that limitation. In addition, it can blend sounds in new ways, giving us entirely new avenues for creating thoroughly unique timbres.

GAZE INTO THE INFINITE

Infinite Pro takes up where PPG Infinite for the iPad leaves off. If you know your way around the app, the Pro version’s GUI should be familiar territory. Navigation buttons for opening the four main pages are in the upper-left corner. To their right are the Program Handling Block, used to open complete programs or portions of programs, and the Program menu, used to initialize and save programs and randomize parameters.

At the GUI’s bottom is the Schematic Keypad, an onscreen MIDI controller, very much like a keyboard, which has buttons instead of keys. Its parameters are extensive, and it allows you to arrange its buttons like a standard keyboard, configure either one or two rows, set up custom scales, and specify various play modes. One of these play modes is Voice Per Channel (VPC), which assigns a different MIDI channel to each voice and makes Infinite Pro compatible with MPE controllers such as the Roli Rise, Haken Continuum, and Roger Linn Design LinnStrument.

What appears between the top section and the Schematic Keypad depends on which navigation button you select. When creating, analyzing, or editing programs, you’ll probably spend most of your time on the Morphing page, which has additional buttons below the navigation buttons for opening its four subpages (see Figure 1). I’ll explain more about the Morphing page and its subpages later.

Fig. 1. Infinite Pro lets you load, process, and blend audio resources in unique combinations. It comes with more than 300 tonal resources and 52 unpitched resources, and it can import audio data to create new resources.

Fig. 1. Infinite Pro lets you load, process, and blend audio resources in unique combinations. It comes with more than 300 tonal resources and 52 unpitched resources, and it can import audio data to create new resources.

The second main page is the Parameter page, which provides more typical oscillator, noise, filter, amplifier, LFO, and envelope controls, as well as a modulation matrix that is much too small (see Figure 2).

Fig. 2. You can edit settings for oscillators, modulators, and other familiar synthesizer functions on the Parameter page.

Fig. 2. You can edit settings for oscillators, modulators, and other familiar synthesizer functions on the Parameter page.

The third page, Effects and Setup, hosts parameters for reverb, overdrive, and synced or free-running delay. Global controls on this page determine polyphony and pitch-bend range and control functions such as whether the keypads transmit MIDI. Also on this page is a section for importing wavetables and audio files. The fourth main page, the Browser, gives you the means to organize programs into lists and apply filters to split them into categories.

FIDDLING WITH INFINITY

The Morpher, Noiser, and Molder sections dominate the main Morphing page. The Morpher is where you mix Sine Resources, in effect superimposing one on the others. Sine Resources are data containing all the partials in a sound, including any changes from the sound’s beginning to its end. You can load five Sine Resources simultaneously and govern their gain and tuning with either the Morpher’s x/y controller or an envelope.

The Noiser is where you mix as many as three Noise Resources, which can either be part of the audible signal, a source for modulating Sine Resources, or both. Noise Resources are unpitched and aperiodic elements, often from sources such as pink noise, percussion instruments, or breath. In addition to its own x/y controller for governing the mix between the three resources, the Noiser has an S/N Mix knob to control the mix between the tonal and unpitched sources and additional knobs that affect its modulation output.

The Molder is a spectral filter that modulates tonal and unpitched signals. It supplies 45 preset filter sweeps that reshape the spectra of Sine and Noise Resources. A time-varying filter envelope is available for modulating the effect. A Balance knob boosts the high or low end, and you can assign any modulation source to control its value. The Molder also lets you import filter sequences created on the iPad in PPG Phoneme.

As mentioned earlier, the Morphing page has four subpages—Sine Parameter, Sine Structure, Sine Analyzer, and Randomize—which allow you to create and edit Sine Resources. A three-dimensional view of the currently selected Sine Resource appears on all of these subpages. You can rotate it and zoom to change your perspective. In this view, individual harmonics appear as slices called tracks. In the Sine Parameter and Structure subpages, you can easily select and even solo an individual track as you edit its amplitude, frequency, and modulation parameters (see Figure 3).

Fig. 3. The Morphing page’s subpages display constituent sine waves in three dimensions and allow you to edit the gain, frequency, decay, and modulation characteristics of individual harmonics, one at a time.

Fig. 3. The Morphing page’s subpages display constituent sine waves in three dimensions and allow you to edit the gain, frequency, decay, and modulation characteristics of individual harmonics, one at a time.

The Sine Analyzer subpage furnishes the controls you need to extract resources yourself. Choose from seven analysis modes—harmonic, inharmonic, or fixed pitch, for example—depending on what type of sound you’re analyzing. Choosing the Noise analysis mode opens a panel for extracting Noise Resources from any audio file.

Overall, I can’t say that Infinite Pro is intuitive to use. It would probably help if the manual were better organized. Some topics are barely mentioned, poorly explained, or difficult to locate. For example, it explains how to back up your custom resources before it even explains what resources are. By its nature, Infinite Pro is unavoidably complicated, and anything that could ease the learning curve would be a welcome relief.

SEEMINGLY LIMITLESS

Like any musical instrument, Infinite Pro does have limits, but its synthesis capabilities are most impressive. It does things other synths only dream of doing. However, it probably isn’t your best choice for reproducing sounds you hear in your head or in your environment. No matter how much time you devote to investigating its capabilities, I suspect it could always lead you into unfamiliar territory. Its functionality is deep and wide, and the ability to import your own sonic material means you could spend a lifetime trying to exhaust its possibilities if you were so inclined.

No doubt about it, Infinite Pro is a complex plug-in, but I can’t imagine how to improve on that complexity in any major way. It will probably take longer than usual to wrap your head around some of its core concepts. Just be prepared to take a while getting up to speed if you want to plumb the depths of its potential.

Considering that most synth users tend to stick with factory programs rather than wandering too far into an instrument’s programming capabilities, Infinite Pro will discourage most from digging very far. Fortunately, its factory programs make it clear that it neither sounds nor functions like other synthesizers, and they are reason enough to buy it. If you have an iPad, I suggest you start with the original Infinite and see if it’s something that interests you.

The ability to control the constantly changing pitch and loudness of every harmonic element in any type of sound is a bit like a Holy Grail to synthesists. Learning to use Infinite Pro with predictable results is not child’s play, but you can still have a lot of fun just mucking about with it, even if you don’t know exactly what you’re doing. To me, that’s the mark of a great synthesizer. Infinite Pro’s presets make it instantly accessible, but if you want to go deeper, it can take you as far as you’re willing. Just don’t forget to occasionally come up for air.

STRENGTHS
Large collection of programs and resources. Edit individual harmonics in any tonal sound. MPE-compatible. Unique sound.

LIMITATIONS
Frustratingly complex and unfamiliar. Modulation matrix is too small. Manual needs improvement.

€149
wolfgangpalm.com

As of this year, editor-at-large Geary Yelton has been contributing to Electronic Musician for half his life. He lives in Asheville, North Carolina.