Sequential OB-6 Polyphonic Analog Synthesizer User Manual

1. Introduction

This manual provides essential information for the setup, operation, and maintenance of your Sequential OB-6 Polyphonic Analog Synthesizer. Please read this manual thoroughly to ensure proper use and to maximize your experience with this instrument. The OB-6 combines the classic sound of Tom Oberheim's original 1970s synthesizers with modern reliability and features, offering a powerful and versatile tool for music creation.

2. Safety Information

To prevent electric shock, fire, or damage to the unit, please observe the following precautions:

• Power Supply: Use only the specified power adapter. Ensure the voltage matches the requirements of your region.
• Moisture: Do not expose the unit to rain, moisture, or excessive humidity. Do not place containers with liquids on the unit.
• Ventilation: Ensure adequate ventilation around the unit. Do not block ventilation openings.
• Heat: Keep the unit away from heat sources such as radiators, heat registers, stoves, or other apparatus that produce heat.
• Cleaning: Disconnect the power before cleaning. Use a dry, soft cloth. Do not use liquid cleaners or aerosol cleaners.
• Servicing: Do not attempt to service the unit yourself. Refer all servicing to qualified service personnel.

3. What's in the Box

Upon unpacking your Sequential OB-6, please verify that all the following items are included:

• Sequential OB-6 Synthesizer
• Power Supply
• User Manual (this document)

If any items are missing or damaged, please contact your dealer or Sequential customer support immediately.

4. Product Overview

The Sequential OB-6 is a 6-voice polyphonic analog synthesizer featuring a pure analog signal path, two voltage-controlled oscillators (VCOs) per voice, a state-variable filter, and a suite of digital effects. Its intuitive front panel provides direct, hands-on control over all parameters.

4.1 Front Panel Controls

The front panel is logically laid out into sections for Oscillators, Mixer, Filter, Envelopes, LFO, Modulation, Effects, Sequencer, and Output. Each section features dedicated knobs and switches for immediate sound shaping.

Image 4.1: Front view of the Sequential OB-6 Polyphonic Analog Synthesizer, showcasing the keyboard, pitch/mod wheels, and the comprehensive control panel with various knobs and buttons for sound design.

4.2 Rear Panel Connections

The rear panel provides all necessary audio, MIDI, and USB connections for integrating the OB-6 into your studio or live setup.

Image 4.2: Rear panel of the Sequential OB-6, displaying the power input, USB port, MIDI In/Out/Thru, footswitch inputs (Sustain, Volume, Filter), and audio outputs (Right, Left, Phones).

5. Setup

5.1 Unpacking and Placement

Carefully remove the OB-6 from its packaging. Place the synthesizer on a stable, flat surface, ensuring sufficient space for ventilation around the unit.

5.2 Power Connection

1. Ensure the OB-6 power switch is in the OFF position.
2. Connect the provided power supply to the power input on the rear panel of the OB-6.
3. Plug the power supply into a suitable AC outlet.

5.3 Audio Connections

Connect the main audio outputs (Right/Mono, Left) on the rear panel to your mixer, audio interface, or amplifier using standard 1/4-inch TS cables. For stereo operation, connect both Left and Right outputs. For mono, use the Left/Mono output.

5.4 MIDI and USB Connections

The OB-6 supports both traditional MIDI (DIN connectors) and USB MIDI for communication with computers or other MIDI devices.

• MIDI: Connect MIDI OUT of your controller/interface to MIDI IN of the OB-6. Connect MIDI OUT of the OB-6 to MIDI IN of your other devices or interface.
• USB: Connect a USB Type A cable from the OB-6's USB port to a USB port on your computer. The OB-6 will appear as a MIDI device in your operating system and DAW.

6. Operating Instructions

6.1 Powering On/Off

To power on the OB-6, flip the power switch on the rear panel to the ON position. The display will illuminate, and the synthesizer will initialize. To power off, flip the switch back to the OFF position. Always power off the unit before disconnecting the power supply.

6.2 Basic Sound Generation

The OB-6's sound engine is based on two voltage-controlled oscillators (VCOs) per voice, a sub-oscillator, a noise generator, a mixer, a state-variable filter, and two envelopes (filter and amplifier).

• Oscillators: Use the OSCILLATORS section to select waveform (saw, pulse), adjust frequency, and fine-tune.
• Mixer: The MIXER section blends the levels of OSC 1, OSC 2, Sub, and Noise.
• Filter: The FILTER section controls the cutoff frequency, resonance, and envelope amount. The OB-6 features a 2-pole, state-variable filter with low-pass, high-pass, band-pass, and notch modes.
• Envelopes: The FILTER ENVELOPE and LOUDNESS ENVELOPE sections control the attack, decay, sustain, and release stages for dynamic sound shaping.

6.3 Program Management

The OB-6 stores a large number of factory and user programs (presets). Use the BANK and PROGRAM buttons to navigate and select programs. To save a modified program, press the WRITE button, select a destination, and press WRITE again to confirm.

6.4 Modulation

The MODULATION section provides control over the LFO (Low Frequency Oscillator) and its routing to various destinations, as well as aftertouch and velocity assignments for expressive control.

6.5 Effects Section

The EFFECTS section offers a range of digital effects including reverbs, delays, chorus, flanger, and phase shifter. Use the dedicated controls to select effect type and adjust parameters.

6.6 Sequencer and Arpeggiator

The OB-6 includes a polyphonic step sequencer and an arpeggiator. Refer to the dedicated sections in the full manual for detailed instructions on programming and using these features.

6.7 Global Settings

The GLOBAL section allows access to system-wide settings such as MIDI channels, tuning, and other preferences. Press the GLOBAL button to enter the global menu and use the data encoder to navigate and adjust parameters.

7. Maintenance

7.1 Cleaning

To clean the OB-6, disconnect it from power. Use a soft, dry, lint-free cloth to wipe down the chassis and keys. Avoid using abrasive cleaners, solvents, or waxes, as these can damage the finish and components.

7.2 Storage

When not in use, store the OB-6 in a clean, dry environment away from direct sunlight and extreme temperatures. If transporting the unit, use a dedicated case to protect it from physical damage.

8. Troubleshooting

This section addresses common issues you might encounter with your OB-6.

• No Sound:
  • Check power connection and ensure the unit is turned on.
  • Verify audio cables are correctly connected to outputs and your sound system.
  • Ensure volume controls (Master Volume, Loudness Envelope Sustain) are not set to zero.
  • Check if a program with very low volume or muted oscillators is selected.
• MIDI Not Responding:
  • Confirm MIDI cables are connected correctly (OUT to IN, IN to OUT).
  • Check the MIDI channel settings in the OB-6's Global menu and ensure they match your controller/DAW.
  • For USB MIDI, ensure drivers are installed (if required by your OS) and the OB-6 is recognized by your computer.
• Unusual Behavior:
  • Try performing a factory reset (refer to the full manual for instructions).
  • Ensure the firmware is up to date.

If you encounter persistent issues not covered here, please contact Sequential customer support.

9. Specifications

10. Warranty and Support

For warranty information, please refer to the warranty card included with your product or visit the official Sequential website. For technical support, product registration, or service inquiries, please contact Sequential customer support through their official channels. Keep your proof of purchase for warranty claims.

Official Website: www.sequential.com