The Arturia KeyStep Pro is a comprehensive four-part MIDI/CV sequencer and controller that serves as a performance and sequencing hub for multiple devices. Building upon the success of the original KeyStep, this "Pro" version significantly expands capabilities while maintaining the portable form factor that made its predecessor so popular.
At its core, the KeyStep Pro features a three-octave mini keyboard with monophonic aftertouch and individual key lights that illuminate to show stored sequencer steps. The unit combines the immediacy of keyboard-based control with sophisticated sequencing capabilities, making it equally suited for studio production and live performance.
The device operates as a four-track sequencer where all parts can function as polyphonic note sequencers with patterns up to 64 steps long. Track 1 can be switched into a dedicated drum mode with 24 trigger lanes, while the other three tracks toggle between sequencer and arpeggiator modes. An additional Control channel provides MIDI CC generation and automation through five touch-sensitive encoders.
The KeyStep Pro excels in connectivity, offering both MIDI and CV outputs alongside USB connectivity. This makes it independent of computer hosts while providing extensive integration options. The unit includes analog trigger outputs for the first eight drum sounds, four complete CV voice outputs (Pitch/Gate/Mod), and comprehensive clock synchronization options.
For pattern organization, the device supports 16 projects with 16 patterns per track, plus scene management and pattern chaining capabilities. Real-time performance features include a built-in looper, pattern variations, and flexible mute controls. The inclusion of a built-in metronome speaker with rear-mounted level control addresses a common pain point with standalone sequencers.
The KeyStep Pro strikes a balance between power and accessibility, using conventional layouts and keyboard-based interaction that feels more immediate than many competing sequencers. While it may not match dedicated sequencers in pure capability or full-sized controllers in MIDI CC functionality, it occupies a unique sweet spot as a highly portable, connectivity-rich all-in-one solution.
Technical Specifications
Sequencing Capabilities
- Tracks: 4 main sequencer tracks + 1 Control track
- Pattern Length: 1-64 steps per pattern
- Polyphony: Up to 16 notes per step on note tracks
- Pattern Storage: 16 patterns per track
- Projects: 16 projects total (onboard storage)
- Scenes: 16 scenes per project for instant pattern/chain recall
- Chains: Single chain per track, up to 16 patterns long
Track Modes
- Track 1: Polyphonic sequencer OR 24-lane drum sequencer
- Tracks 2-4: Polyphonic sequencer OR arpeggiator
- Control Track: 5-encoder MIDI CC automation
- Drum Mode: 24 individual gate lanes with polymetric capability
- Arpeggiator: Multiple directions, ranges, speeds, Poly Arp mode
Connectivity - MIDI
- MIDI Outputs: 2 full-sized MIDI outputs (duplicate, not separate ports)
- USB: USB MIDI connectivity
- MIDI Channels: Discrete channel assignment required for multiple devices
- MIDI Machine Control: Transport control capability
Connectivity - Analog/CV
- CV Outputs: 4 complete voice sets (Pitch/Gate/Mod per voice)
- Drum Triggers: 8 analog trigger outputs (first 8 drum lanes)
- Clock Output: Analog clock output
- Reset Output: Analog reset output
- Clock Input: Analog clock input
- CV Routing: Flexible assignment of sequencer tracks to CV voices
- Polyphonic CV: Up to 4-voice polyphonic CV output
- Mod Sources: Velocity or Aftertouch per voice (switchable)
Sequencing Features
- Recording Methods: Real-time (quantized/unquantized), step entry, "press and play"
- Recording Modes: Overdub or overwrite
- Pattern Operations: Transpose (in key), invert, length adjust, nudge
- Playback Variations: Speed/order modifications via shift functions
- Looper: 1/4, 1/8, 1/16, 1/32 note loops with moveable loop points
- Randomness: Per-step probability control (drum mode), dynamic addition (arp mode)
Step Parameters (Per Step Editing)
- Pitch: Individual step pitch adjustment
- Gate Length: Per-step gate timing
- Velocity: Per-step velocity control
- Timing: Micro-timing adjustment per step
- Randomness: Step trigger probability
Performance Controls
- Modulation: Touchstrip per track (assignable MIDI CC)
- Aftertouch: Monophonic aftertouch transmission
- Transport: Dedicated transport controls
- Tempo Controls: Dedicated tempo encoder, swing encoder, tap tempo
- Mute Controls: Per-track and per-drum-lane muting
- Pattern Switching: Instant or queued pattern changes
Keyboard
- 3-octave mini keys
- Monophonic aftertouch
Controls
- 16 step buttons
- 5 touch-sensitive encoders
Power and Management
- Power: USB-powered operation
- Backup Software: MIDI Control Center for project backup/loading
- Global Settings: Drum map starting note, CV mod source assignments
- Pattern Management: Copy/paste functionality with multi-button combinations
Limitations
- No MIDI CC controls within individual sequencer tracks (separate Control track only)
- CV mod outputs not assignable to touchstrip or Control encoders
- Global rather than project-specific settings for some parameters
- Single step editing only (no multi-step parameter adjustment)
- No real-time parameter capture without simultaneous note recording
- Scene/Project launching always from beginning
- No duplicate function for patterns (requires copy/paste/launch sequence)
Physical Specifications
- Dimensions: 589 x 208 x 38 mm
- Weight: 2.7kg
