Pro 3 Keyboard

A hybrid instrument, the Pro 3 features three classic analog lters (Prophet-6, OB-6, and ladder) and three oscillators (two VCOs and one wavetable oscillator) along with a powerful new 16-track sequencer, and the ability to connect with modular synths through its four control voltage ins/outs.

“In many ways the Pro 3 is the evolution of a concept that started with the classic Sequential Circuits Pro-One,” said Sequential founder Dave Smith: “Pack as much power as possible into a compact footprint and make it sound awesome. To do that, webuilt on the strengths of its modern-day counterpart, the Pro 2, and created a worthy successor to both that sets a new benchmark for raw power and versatility.”

Part of this sonic versatility comes from the Pro 3’s oscillators: Two voltage controlled oscillators provide traditional triangle, saw, and pulse waves with waveshaping, while a third digital wavetable oscillator provides 32 tables of 16 waves each with wave morphing. Three vintage-style lters shape the sound of these oscillators. Filter 1 is a 4-pole low-pass design based on the Prophet-6 lter. Filter 2 is a classic transistor ladder lter with optional resonance compensation to preserve its low-end punch. Filter 3 is a classic 2-pole, state-variable design based on the OB-6 lter that can be continuously varied between low-pass, notch, and high-pass operation, with an optional band-pass mode. A Drive control provides additional punch to all three lters.

The feature set of the Pro 3 is rounded out with a multimode arpeggiator, three LFOs, four loopable ADSR+delay envelopes, dual digital effects (delays, reverbs, and various time-based effects), tuned feedback, analog distortion, and extensive modulation possibilities. The LFOs, delay, and arpeggiator can be synced to either the internal clock or an external MIDI clock. A programmable position-sensitive touch slider and pitch and mod wheels provide nuanced control over live performance. The synth is also capable of 3-voice paraphonic operation. This makes it possible to play 3-note chords where the three individual oscillators share a common lter and envelopes.

The full-featured sequencer provides 16-track sequences of up to 64 steps, with ratcheting, variable gate and sequence lengths, multiple playback modes, and paraphonic operation. It also syncs to MIDI clock and external audio input, and inputs/outputs control voltages. In addition to notes, sequence tracks can control any parameter in the 32-slot, 171-destination modulation matrix.

Another key feature of the Pro 3 is its four scalable rear-panel control voltage inputs and outputs, which allow compatibility with modular synths. Control voltages are routed from within the modulation matrix and run at audio rates for extreme modulation effects. “We wanted to make the Pro 3 as exible as possible,” said Smith. “The CVs and deep mod matrix make it a mini modular in its own right — without all the patch cables.”