The Moog Sub 37 represents a significant evolution in Moog's synthesizer lineage, combining the best elements from the Voyager, Minitaur, and Sub Phatty into a comprehensive analog instrument with digital control. Released as Moog's answer to user feedback requesting more accessible controls and expanded functionality, the Sub 37 delivers both the classic Moog sound and modern performance capabilities in a compact, stage-ready package.

Built around a steel chassis with wooden end-cheeks, the Sub 37 features a comprehensive control panel that makes nearly all functions immediately accessible without diving into menus. The synthesizer's distinctive design philosophy centers on providing "hands-on" control while maintaining the sonic character that made Moog legendary in the 1970s.

Sound Architecture

The Sub 37 employs an analog signal path controlled by digitally generated modulators and contour generators. At its heart are dual oscillators based on the Minitaur oscillator core followed by the Voyager's variable waveshaper architecture. These oscillators offer a continuous spectrum of waveforms from triangle through sawtooth to square and pulse waves, with footages at 16', 8', 4', and 2'. A square-wave sub-oscillator sits one octave below Oscillator 1, while hard sync capabilities and ±7 semitones of detuning provide additional sonic flexibility.

The instrument's most distinctive feature may be its duophonic capability, allowing independent control of oscillators for two-note polyphony. Oscillator 2 can be allocated to higher or lower notes, or disconnected from the keyboard entirely to function as a drone with a three-octave frequency range.

The filter section centers on Moog's classic 20Hz-20kHz Ladder Filter with four selectable cutoff slopes (6dB, 12dB, 18dB, and 24dB per octave), all capable of self-oscillation. The Multidrive system provides two distortion circuits - one before the filter, one after - while a feedback loop (based on the classic Minimoog trick) can transform mild sounds into aggressive, overdriven textures.

Modulation & Control

The Sub 37's modulation system features two comprehensive sections, each containing an LFO with five waveforms (triangle, square, saw, ramp, and sample & hold) operating from 0.1Hz to 100Hz or 1Hz to 1kHz. Beyond the basic LFO functions, each modulator can access 10 additional modulation sources and route to 83 possible destinations, creating extensive sound-shaping possibilities.

The contour generators represent a particular strength, offering six-stage DAHDSR envelopes that can function as conventional four-stage generators or expand to include Delay and Hold stages. Both filter and amplifier contours feature independent legato/multi-triggering, sync options, looping capabilities, and can even function as complex LFOs. The contours respond to keyboard tracking, affecting attack, decay, and release times based on note position.

Performance Features

Performance capabilities include a comprehensive arpeggiator with Up, Down, Up/Down, Note Order, and Random modes, plus sync options and programmable gate lengths. The 64-step sequencer allows per-patch programming with rests, ties, and legato transitions, particularly effective when combined with the duophonic mode and portamento settings.

The instrument offers extensive note priority options (high, low, last-note) selectable globally or per-patch, alongside single or multi-triggering modes. Three portamento types (linear constant rate, linear constant time, and exponential) can be applied to individual oscillators or both simultaneously, with gated and legato options.

Technical Specifications

Keyboard

• 37 semi-weighted keys with velocity and pressure (aftertouch) sensitivity

Sound Generation

• Architecture: Analog/digital hybrid with analog signal path and digital control
• Oscillators: 2 main oscillators plus 1 square-wave sub-oscillator
• Waveforms: Continuous spectrum from triangle → sawtooth → square → pulse
• Footages: 16', 8', 4', 2'
• Sub-oscillator: Square wave, one octave below Osc1
• Sync: Hard sync between oscillators
• Detuning: ±7 semitones (Osc2 relative to Osc1)
• Beat Frequency: ±3.5Hz consistent detune
• Duophonic Mode: Independent oscillator allocation for two-note polyphony
• Drone Mode: Osc2 disconnectable from keyboard with 3-octave range

Filter

• Type: Classic Moog 20Hz-20kHz Ladder Filter
• Slopes: 6dB, 12dB, 18dB, 24dB per octave (all self-oscillating)
• Keyboard Tracking: 0-200%
• Modulation: Positive and negative polarity from dedicated contour generator
• Overdrive: Multidrive with pre and post-filter distortion circuits

Mixer Section

• Inputs: Osc1, Osc2, Sub-oscillator, Pink noise, External/Feedback
• Feedback Loop: Based on classic Minimoog external input trick
• Noise: Pink noise generator with intentional grain/distortion at high levels
• Overdrive: Oscillator levels above 12 o'clock overdrive filter input

Contour Generators

• Type: Dual DAHDSR (6-stage) digitally generated, analog filtered
• Stages: Delay, Attack, Hold, Decay, Sustain, Release
• Timing Range: 1ms to 10s (Attack, Hold, Release), up to 20s (Decay)
• Attack Types: Linear or exponential (independently selectable)
• Additional Parameters: Velocity Amount, KB Track (keyboard tracking)
• Special Functions:
  • Legato/multi-triggering
  • Retrigger reset options
  • MIDI sync capability
  • Looping (converts to 5-stage LFO)
  • Latch function

Modulation System

• Modulators: 2 comprehensive modulation sections
• LFO Waveforms: Triangle, square, sawtooth, ramp, sample & hold
• LFO Range: 0.1Hz to 100Hz or 1Hz to 1kHz
• Additional Sources: 10 programmable modulation sources per section
• Destinations: 83 programmable destinations per section
• Standard Destinations:
  • Oscillator pitch (Osc1, Osc2, or both)
  • Filter cutoff frequency (±polarity)
  • Oscillator waveshape
  • Noise level
  • VCA level
  • Cross-modulation between modulators
• Controllers: Mod wheel, velocity, aftertouch, MIDI CC#2 (breath control)
• Control Mode: Currently multiplicative (additive mode planned)

Portamento/Glide

• Types: Linear constant rate, linear constant time, exponential
• Application: Osc1, Osc2, or both oscillators
• Modes: Gated (stops on key release), Legato (only between overlapping notes)

Performance Features

• Arpeggiator: Up/Down/Up-Down/Note Order/Random modes
• Arpeggiator Features: Rate control, tap tempo, sync options, gate lengths, clock divisions, end note handling, Invert function
• Sequencer: 64-step per patch
• Sequencer Features: Record/playback, rests, ties, legato transitions, duophonic mode support
• Note Priority: High/Low/Last-note (global or per-patch)
• Triggering: Single/multi-triggering (per-patch)
• Sync: Internal clock or MIDI Clock for all timing functions

Memory & Storage

• Patch Memory: 256 locations
• Per-patch Settings: Individual volume levels, all synthesis parameters
• Patch Dumping: Current edit buffer, current patch, all patches, complete synth state

Audio I/O

• Main Output: 1/4" mono output
• Headphone Output: 1/4" TRS stereo
• Audio Input: 1/4" mono (for external signal processing/feedback)
• Power: Internal 100V-240V, 50/60Hz AC supply via IEC socket

Control Voltage I/O

• CV Inputs:
  • 1V/Oct pitch CV
  • Filter CV
  • Amplifier/Volume CV
  • +5V Gate input
• CV Outputs: None (notable omission)

MIDI Implementation

• Physical Connections: 5-pin DIN In/Out, USB (MIDI only, no audio)
• MIDI Features:
  • Selectable DIN/USB/both operation
  • Configurable In/Out channels
  • Data filtering options
  • Data merging and echo
  • 7-bit and 14-bit CC transmission for panel controls
  • NRPN support for all ~150 parameters
  • Full SysEx implementation
  • No computer drivers required for USB connection

Display

• Backlit 128 x 64 pixel LCD screen

Software Integration

• Editor: Standalone and VST/AU/AAX versions (in development at time of review)
• Features: Patch editing/management, DAW automation, CV mapping options
• Compatibility: Cross-platform support planned

Additional Features

• KB Reset: Oscillator and LFO initialization on key press
• Knob Shift: Secondary function access for expanded parameter control
• Multi-unit Chaining: Multiple Sub 37s can be connected for expanded polyphony
• Quick Startup: Stable operation within seconds of power-on, no need for a warm-up
• Panel Layout: Comprehensive "hands-on" control with minimal menu diving

Physical paramaters

• Construction: Steel chassis with wooden end-cheeks
• Size: 6.8 x 26.8 x 14.8" / 171.5 x 679.5 x 374.7 mm
• Weight: 10kg