Sequential OB-6 Keyboard 6-Voice Polyphonic Analog Synthesizer

OB-6 Polyphonic Analog Synthesizer

The Sequential (Dave Smith Instruments) OB 6 is a Polyphonic Analog Synthesizer that is a result of a collaboration between the two most influential designers in poly synth history, Dave Smith and Tom Oberheim. This beautifully designed synth adds modern enhancements such as studio-quality effects, a polyphonic step sequencer, an arpeggiator, and more. No other modern analog poly synth can boast such a pedigree or such a massive, in-your-face sonic signature.

Sequential OB-6 Features

Vintage SEM Tone
The OB-6 sound engine is inspired by Tom’s original SEM, the core of his acclaimed 4-voice and 8- voice synthesizers. It features two discrete voltage-controlled oscillators (plus sub-oscillator) per voice with continuously variable waveshapes (sawtooth and variable-width pulse, plus a triangle wave on oscillator 2). The classic Oberheim-inspired 2-pole, state-variable, resonant filter provides low-pass, high-pass, band-pass, and notch functionality. Voltage-controlled amplifiers complete the all-analog signal path.

Dual Effects
The dual effects section provides studio-quality reverbs, delays (standard and BBD), chorus, flangers, and faithful recreations of Tom’s original phase shifter and ring modulator. While the effects themselves are digital, with 24-bit, 48 kHz resolution, a true bypass maintains a full analog signal path.

X-Mod and Poly Step Sequencing
Also present is X-Mod, which expands the tonal palette and makes it easy to create dramatic and unconventional sounds. Modulation sources are filter envelope and oscillator 2, both with bi-polar control. Destinations include oscillator 1 frequency, oscillator 1 shape, oscillator 1 pulse width, filter cutoff, and filter mode. The polyphonic step sequencer allows up to 64 steps and up to 6 notes per step. You can create sequences polyphonically, with rests, and sync to an external MIDI clock. The full-featured arpeggiator can be synced to external MIDI clock as well. Unison mode features configurable voice count (1-6 voices), chord memory, and key modes.

Easy to Program
The knob-per-function front panel puts virtually all OB-6 functions at your fingertips. Included are 500 permanent factory programs and 500 re-writable user programs. Turning on the Manual button enables live panel mode, in which the sound of the OB-6 switches to its current front panel settings. In this state, what you see is what you hear.

Easy to Play
This analog powerhouse is packed into a four-octave, semi-weighted keyboard with velocity and channel aftertouch, making it perfect for stage or studio.

Specifications

• Oscillators
• Two discrete VCOs per voice
• Continuously variable wave shape (sawtooth and variable-width pulse, plus triangle on oscillator 2) per oscillator
• Pulse width per oscillator
• Hard sync: oscillator 1 syncs to oscillator 2
• Square wave sub-octave generator (oscillator 1) per voice
• Low frequency mode (oscillator 2)
• Keyboard tracking on/off (oscillator 2)
• Oscillator detune amount for increased tuning instability, from subtle to extreme
  
  
• Mixer
• Oscillator 1 amount
• Oscillator 1 sub-octave amount
• Oscillator 2 amount
• White noise amount
  
  
• State-varable filter
• Two-pole, resonant, filter per voice with low-pass, high-pass, band-pass, and notch functionality inspired by the original Oberheim SEM filter
• Bi-polar filter envelope amount
• Velocity modulation of envelope amount
• Keyboard tracking: off, half, full
  
  
• Filter envelope
• Four-stage (ADSR) envelope generator
• Velocity modulation of envelope amount
  
  
• Amplifier envelope
• Four-stage (ADSR) envelope generator
• Velocity modulation of envelope amount
  
  
• Low frequency oscillator
• Five wave shapes: sine, sawtooth, reverse sawtooth, square, and random (sample and hold)
• Clock sync (internal or external MIDI clock)
• Initial amount
• Mod destinations: oscillator 1 frequency, oscillator 2 frequency, oscillator 1 and 2 pulse width, filter cutoff, filter mode, amp
  
  
• X-Mod
• Sources: filter envelope (bi-polar) and oscillator 2 (bi-polar)
• Destinations: oscillator 1 frequency, oscillator 1 shape, oscillator 1 pulse width, filter cutoff, filter mode, normal to band-pass filter
  
  
• Aftertouch
• Source: channel (mono) aftertouch with bi-polar amount
• Destinations: oscillator 1 frequency, oscillator 2 frequency, LFO amount, amplifier envelope amount, filter envelope amount, filter mode
  
  
• Clock
• Master clock with tap tempo
• BPM control and display
• MIDI clock sync
• Arpeggiator
• Selectable note value: 16th note, 8th note triplet, 8th note, dotted 8th note, quarter note
• One, two, or three octave range
• Up, down, up/down, random, and assign modes
  
  
• Sequencer
• Polyphonic step sequencer with up to 64 steps and rests
  
  
• Effects
• Stereo analog distortion
• Dual, 24-bit, 48 kHz digital effects, including: reverb (room, hall, plate, spring), delay (full bandwidth digital delay and emulated bucket brigade), chorus, flanger, phase shifters, and ring modulator
• Delay sync
• True bypass maintains fully analog signal path when digital effects are off
  
  
• Performance controls
• Full-sized, semi-weighted, 4-octave keyboard with velocity and aftertouch
• Backlit pitch and mod wheels
• Spring-loaded pitch wheel with selectable range per program (1 to 12 semitones up and down)
• Transpose controls for an 8-octave range
• Hold switch latches held notes on
• Polyphonic portamento
• Unison (monophonic) mode with configurable voice count, from one to all six voices, chord memory, and key modes
• Manual switch: when on, the front panel is live; what you see is what you hear
  
  
• Patch memory
• 500 user and 500 factory programs in 10 banks of 100 programs each
• Direct program access, including single-button access to the current set of 10 programs
  
  
• In/Out
• Left/mono and right audio outputs (2 x 1/4” phone jack)
• Headphone output (stereo, 1/4” phone jack)
• MIDI in, out, and thru ports
• USB for bidirectional MIDI communication
• Filter cutoff expression pedal input
• Volume expression pedal input
• Sustain footswitch input
• Sequencer start/stop footswitch input
  
  
• Power
• IEC AC power inlet for internal power supply
• Operates worldwide on voltages between 100 and 240 volts at 50 to 60 Hz; 30 watts maximum power consumption
  
  
• Diamentions: 31.8” L x 12.7” W x 4.6″ H (80.7 cm x 32.3 cm x 11.7 cm)
• Weight: 20 lbs (9.5 kg)