Rob Papen QUAD-2: the phase distortion synth gets a full rework

Dutch developer Rob Papen has released QUAD-2, a new version of its phase distortion and waveshaping synthesizer, as a plugin for macOS and Windows. The official page describes it as a reworked QUAD: a redesigned interface, a ribbon controller, new filter types and new effects. QUAD started life in 2014 as a Reason Rack Extension, before a VST version followed in 2020.

Who it is for

• Sound designers after edgy digital tones: phase distortion produces bright, metallic or vocal-like timbres that a plain filter struggles to reach.
• QUAD and QUAD-RE owners, who keep familiar ground and get a discounted upgrade.
• Producers who perform their modulation: the ribbon is a full modulation source and can be recorded as a parameter.

What it costs

A demo version is available. The licence covers two computers, with online or offline activation.

There is no CLAP version and, according to the developer, no NKS support yet (Native Instruments’ format for its keyboards). Our guide to VST3, AU, AAX and CLAP plugin formats helps check compatibility with your host.

How QUAD-2 works

Phase distortion, popularised by Casio’s CZ series in the mid-1980s, reads a simple waveform at a varying speed within each cycle, which bends a sine into a saw, square or pulse shape. Waveshaping runs the signal through a transfer function that reshapes its profile. QUAD-2 chains both inside each oscillator.

Oscillators

• Two oscillators, each with a sub-oscillator, a Spread control (several detuned oscillators in one) and a choice of classic, additive and spectral waves.
• Phase distortion and a waveshaper in each oscillator, driven by two XY pads, with around twenty curves (Fold, Fuzz, Cos, Rez, Shift…).
• Cross-oscillator modulation: ring modulation, phase modulation, four FM modes, and a String model with length and damping.
• Two hand-drawn user waveforms (U-Wave).

Filters

• Two filters, 43 types plus 11 special types (comb, ring and AM modulation, FM, feedback), including the Cream filter taken from Albino-3 Legend, another Rob Papen synth.
• Nine routings: serial, parallel, one oscillator per filter, with mix or morph between the two.

Modulation, arpeggiator and effects

• Two modulation envelopes on top of the filter and amp envelopes, each with a Sustain-Fade stage that lets the sustain level decay; our guide to the ADSR envelope covers each stage. Two LFOs.
• Ribbon controller with tempo-synced spring-back and 12 dedicated modulation slots, on top of a 12-slot matrix with more than 200 destinations.
• 16-step arpeggiator with ratcheting (fast repeats of a step) and a free row to modulate the XY pads.
• Effects: stereo tape delay, reverb, 11 modulation effects (including chorus and talkbox), 33 distortions, EQ and an FX filter.
• 16 voices, poly, mono, legato and unison modes; more than 1200 presets organised by a bank manager.

Rob Papen’s official introduction:

What it competes with

• Arturia CZ V, the Casio CZ emulation in V Collection: original-style phase distortion, faithful to the hardware, whereas QUAD-2 uses it as the starting point for a modern synth with two filters and effects.
• Vital, a free wavetable synth whose waveform-reading warps (Bend, Squeeze) work on the same principle, without being labelled phase distortion.

At $49, QUAD-2 sits at the low end of commercial synth pricing. Its appeal is the combination of phase distortion, waveshaping and the ribbon rather than a single speciality, and its interface is more modern than the first version, which was held back by the Reason format. Other recent releases, such as Imaginando’s COLAPSO, are collected in our synth plugins section.

The full feature list is on Rob Papen’s features page, and pricing on the purchase page.