The Sequential OB-6 Module is a portable desktop analog polysynth module that features two oscillators and a 64-step polyphonic step sequencer. It is a collaboration between two of the most influential poly synth designers in the world, Tom Oberheim and Dave Smith. This synth offers a perfect balance between Oberheim’s signature sound and modern innovations.
Vintage SEM Tonality
The OB-6 Module’s sound engine was developed and inspired by Tom Oberheim’s original SEM, which served as the foundation for his 4-note and 8-note synths. The sound engine has two discrete voltage-controlled oscillators (VCOs) per voice, plus continuously variable waveshapes. The 2-pole, state-variable resonant filter provides a range of parameters including low-pass, high-pass, notch, and band-pass functionality.
Powerful Built-in Effects
The OB-6 Module also has a range of built-in effects that allow you to tweak and edit your sounds while playing. These digital effects run at 24-bit/48kHz resolution and include Delay, Reverb, Chorus, Flangers, Phase Shifter, and Ring Modulation. The true bypass ensures the full analog signal path.
Poly Step Sequencing and X-Mod
The X-Mod function (Crossmodulation) allows you to modulate the frequency of two oscillators, expanding your tonal palette and creating the means to build unconventional and unique sounds. The modulation sources are the filter envelope and oscillator 2, with both featuring bi-polar controls. You can then choose from a range of destinations including Oscillator 1 freq, Oscillator 1 pulse width, filter cutoff, shape, and more.
In addition to cross-modulation, the OB-6 features a polyphonic step sequencer that supports up to 64 steps and up to 6 notes per step. This versatile sequencer allows you to arrange and create sequences and synth to an external MIDI clock. The unison mode in the sequencer features a configurable voice count, key modes, and more.
Oscillators and Mixer
The OB-6 Module has two discrete VCOs per voice with continuously variable wave shape (sawtooth and variable-width pulse, plus triangle on oscillator 2), pulse width per oscillator, and hard sync capability. The oscillator 1 syncs to oscillator 2, and there is a squave wave sub-octave generator (oscillator 1) per voice. You can adjust the low-frequency mode (oscillator 2) and keyboard tracking on/off (oscillator 2). Additionally, there is an oscillator detune amount for increased tuning instability ranging from subtle to extreme.
The mixer includes oscillator 1 amount, oscillator 1 sub-octave amount, oscillator 2 amount, and white noise amount.
State-Variable Filter and Envelope
The state-variable filter is a two-pole, resonant filter per voice with low-pass, high-pass, band-pass, and notch functionality inspired by the original Oberheim SEM filter. The bi-polar filter envelope amount can be modulated by velocity, and there is keyboard tracking on/off. The filter envelope has a four-stage (ADSR) envelope generator.
Amplifier and Envelope
The amplifier has a four-stage (ADSR) envelope generator that can also be modulated by velocity.
Low-Frequency Oscillator and Aftertouch
The OB-6 Module’s low-frequency oscillator has five wave shapes including sine, sawtooth, reverse sawtooth, square, and random (sample and hold).