Wolfgang Palm PPG Phonem review

Coming from the brilliant mind of digital synthesis pioneer Wolfgang Palm, PPG Phonem serves up a combination of vocal and wavetable synthesis, sequencing and modulation.

Its raison d'etre is the creation of synthesised vocal phrases, supplemented with the included wavetable oscillator and triggered via MIDI just like a conventional synth.

The three round buttons at the top of the GUI switch between the top-level Timeline, Parameter and Effects/Setup pages, and sit alongside a central panel for browsing, loading and saving programs and banks.

The synthesis happens in the Timeline page, with its Phonem, Track and Wave subpages called up using the three top-left buttons. Words and phrases (called utterances) are sequenced in the Phonem page by arranging short snippets of synthesised sound (phonemes) on the eponymous timeline.

Phonemes are essentially syllables, displayed phonetically - 'aw' (sounds like "ow") and 'dh' (sounds like "th"), for example - and there are 46 English ones included, as well as five German and four French.

The Phoneme source signal is generated by a "spectral oscillator" called the Excitation Generator - the frequency spectrum of which is controlled by moving the bass, mid and high frequency nodes in the Excitation Editor - and a multi-resonant filter, the two working together to emulate the human vocal tract.

The filter comprises 12 independent resonators, their frequency, gain and Q width adjustable in the central Resonator Editor. Each resonator can be subtly tweaked to change the flavour of the phoneme or pushed to extremes, but deliberate range limits are in place to keep them sounding 'vocal'.

Five human Voice options (two female, one male) are available, based on analysed sounds from vocalists and narrators. There's also an 'effect' library containing a range of silent phonemes for use in between different combinations of words; and the FX phoneme, for creating non-vocal sounds, with no limit to the adjustment range of its resonators.

The Source menu lets you cycle through the utterances linked to each program, the phonemes for the selected one appearing in the Phoneme Timeline below. (Note that a Phonem program includes links to the utterances it uses - the actual utterance files and wavetables used are saved in Phonem's resource folder.)

Clicking the New Text button enables text entry into the Source field, for synthesis using a nifty American English text-to-speech converter - if this doesn't recognise the words you need, you can create an utterance from scratch by typing your own phonemes into the box below. This can involve a bit of trial and error, but it generally works well.

Walk the 'line

Sequencing of phonemes is done in the Phoneme Timeline, where each phoneme is contained in a 'frame'. Frames are inserted, deleted, copied and pasted via the right-click menu, and the phoneme in each one is selected using the Phoneme Selector, listing the aforementioned 55 phonemes.

The shape and playback behaviour of the selected frame are adjusted using the controls below the Timeline. Length extends or shortens the phoneme without affecting its pitch; Blend crossfades between phonemes; and Steep controls the transition between phonemes, from linear to a more natural-sounding cosine.

Cutoff, meanwhile, determines the frequency above which the signal is filled with noise (adjusted on the Parameter page) - ideal for adding extra sibilance, particularly; Aspiration adds a bit of distortion; and Fricative adjusts the volume of noise in 'unvoiced' phonemes, such as plosives, sibilances and, well, fricatives.

The Track section houses two automation- style modulation tracks, one hardwired to pitch (obviously essential for turning a monotonous vocal into actual singing), the other freely assignable in the modulation matrix.

Rounding off the Timeline page is the Access Mode menu, featuring a variety of options for controlling how the frames in the Phonem section are played back, including the Time Envelope (for timestretching, forward/backward directional play and freeze effects), the placement of Start/End Markers, and playback of the selected frame only.

Parameters and pads

The Parameter page houses a comprehensive modulation matrix, with 21 mod sources (including six envelopes, four LFOs, two MIDI- controllable X/Y pads, and the vocal-specific Vibrato, Growl and Flutter generators) and 20 targets (LFO depth, pitch, pan, etc).

The Oscillators subpage contains controls for pitching the excitation generator up and down by up to four octaves and adding unison detuning, while the Noise section is where the colour and volume of the aforementioned noise signal are adjusted. Activating Song Mode tells Phonem to sequentially play all of the utterances contained within the program, for crafting whole vocal verses or longer sentences.

The Effects page offers simple reverb and delay modules, a Global tuning and voicing section, Master Volume and Drive, and Import of other PPG wavetables.

The final word

Phonem's vocal synthesis is extensively tweakable using the sound-shaping, pitch tracking and modulation controls, giving impressive if obviously synthesised results that electronic producers will have endless creative fun with.

We also like the extra sound design possibilities opened up by the Wave oscillator, and the ability to import WaveGenerator and WaveMapper2 wavetables is a welcome bonus for owners of either. Not being able to adjust or modulate the mix of vocal utterance and wave oscillator is a downer, the CPU usage can get a little high with complex patches, and the interface is a little confusing in places, but Phonem would make a great-sounding, unusual and thoroughly relevant addition to anyone's synth collection.