The Waldorf Pulse is a 2U rackmount analog monosynth that delivers authentic vintage analog sound without the reliability issues of aging vintage equipment. With its distinctive Toblerone-like depth and classic Waldorf grey chassis with white/orange lettering reminiscent of the Wave and Microwave series, the Pulse combines old-school analog warmth with modern digital control precision.

At its heart, the Pulse features three true analog oscillators that work together to create rich, fat sounds by filling phase cancellation gaps that can occur with two-oscillator designs. The oscillators employ different generation methods - digitally-controlled pulse waves, voltage-controlled sawtooth, and a complex triangular waveform combining sawtooth processing with additional circuitry for the down-ramp.

The filter is based on the legendary Minimoog cascade design but with improved stability and tracking accuracy. Unlike the original Minimoog filter that would detune with heat, the Pulse's filter maintains perfect tuning and offers up to 10 octaves of keyboard tracking. The filter's character changes dynamically with input level - lower oscillator volumes produce a Roland-like character while higher volumes yield classic Minimoog-style warmth.

The Pulse's standout feature is its complete MIDI implementation - every single parameter change generates and responds to MIDI controller messages rather than complex SysEx data. This makes it incredibly easy to automate and sequence, with modulation update rates of 523Hz (every 1.9ms) providing analog feel with digital precision.

The instrument uses a matrix-based programming system accessed through six solid knobs and a mode button, with a simple 3-character display showing status information. While it lacks an LCD screen, the programming workflow is intuitive and efficient once learned.

Technical Specifications

Oscillators

• Count: 3 analog oscillators
• Waveforms:
  • Sawtooth (all oscillators)
  • Pulse with variable width (oscillators 1 & 2)
  • Triangle (all oscillators)
• Special Features:
  • Oscillator sync (osc 2 slaved to osc 3)
  • Cross modulation (mathematically identical to ring modulation)
  • Variable pulse width modulation on oscillators 1 & 2

Filter

• Type: True analog 24dB/octave resonant low-pass filter
• Design: Based on Minimoog cascade circuitry with improved stability
• Features:
  • Self-oscillation at high resonance values
  • Pitched tone tracking across full MIDI range
  • Keyboard follow range: ~10 octaves without detuning
  • Character changes with input level (Roland-like at low levels, Minimoog-like at higher levels)
  • 100% stable voltage control

Envelopes

• Count: 2 ADSR envelopes
• Attack Time: 1.9ms minimum (digital)
• Features:
  • Individual keyboard tracking rates
  • 4 triggering modes per envelope
  • Envelope 1: Intended for filter
  • Envelope 2: Intended for output contour
  • Update rate: 523Hz (every 1.9ms)

LFOs (Low Frequency Oscillators)

• Count: 2 LFOs
• LFO 1 Waveforms: Sine, triangle, sawtooth, pulse, sample & hold (random)
• LFO 2 Waveforms: Triangle with delay feature
• Maximum Speed: 261Hz (C3 note)
• Features:
  • Free-running (not sync'd to note trigger)
  • LFO speed can be modulated by keytrack for melodic playing
  • Update rate: 523Hz

Modulation Matrix

• Routing Slots: 4 independent modulation routings per patch
• Modulation Sources:
  • Off, LFO1, LFO1 & Mod Wheel, LFO1 & Aftertouch
  • LFO2, LFO2 & Env 1, Env 1, Env 2
  • Velocity, Keytrack, Pitch follow, Pitchbend
  • Mod Wheel, Aftertouch, Breath Control, Control X
• Modulation Destinations:
  • Pitch (overall), Osc1/2/3 Pitch
  • Pulse width 1 & 2
  • Osc 1/2/3 level, Noise level
  • Cutoff, Resonance, Volume, Panning
  • LFO 1 Speed, Mod 1 Amount

Performance Features

• Portamento: Normal and fingered modes
• Arpeggiator:
  • Internal sync or MIDI clock sync
  • Time intervals: Up to 32nd notes with triplet options
  • 16 pattern variations (undocumented)
  • Range: Up to 10 octaves
  • Patterns: Up, down, alternating, random
  • Real-time MIDI control

Memory

• Total Patches: 99 locations
• User Programmable: 40 patches (locations 1-40)
• Factory Presets: 59 patches (locations 41-99)
• Random Patch: Programs beyond 99 generate random patches
• Edit Buffer: Temporary storage prevents patch loss during editing

MIDI Implementation

• Controller Messages: Every parameter sends/receives MIDI CC
• Update Rate: 523Hz modulation processing
• Special MIDI Features:
  • MIDI tuning request support
  • Real-time arpeggiator control
  • Program dump with controller values (header $4b)
  • Device ID for SysEx transmission

Physical Specifications

• Format: 2U rackmount module
• Depth: Nearly as deep as it is high
• Controls: 6 solid knobs, mode button, shift key
• Display: 3-character readout
• Color Scheme: Grey chassis with white/orange lettering

Connectivity

• MIDI: In, Out, Thru (3 standard MIDI sockets)
• Audio Outputs: Stereo outputs (even though monophonic)
• Power: 12V external adapter (Euro-type/anglicised plug)
• Future Expansion: CV/Gate output planned for hardware upgrade or Pulse MkII

Audio Signal Path

• Mixer Section: Designed to be overdriven for character
• Noise Source: Pink noise (described as harsh-sounding)
• Amplifier: Fully controllable stereo output with auto-panning capability
• Output Stages: Voltage-controlled with 100% stability

Programming Interface

• Navigation: Matrix-based with mode button stepping through 6 levels
• Additional Levels: 6 more levels accessed via shift key
• Status Indication: Green LED shows current mode position
• Value Checking: Hold mode button and turn knob (requires two hands for rightmost controls)
• No LCD: Patch numbers only (no patch names)