mLab OB-Xa MIDIcontrol

The magicBox MIDI interface for the Oberheim OB-Xa COMPUTER INTERFACE port.

Made in Germany by mLab · Contact mLab

Compatibility and versions

This page documents the OB-Xa-specific magicBox and its controller assignments. It works with original OB-Xa synthesizers; firmware Rev C is recommended. OB-Xa instruments with third-party firmware such as Kenton or Encore are not supported by this interface.

The newer all-in-one magicBox3 has its own setup files and MIDI implementation. Use the documentation for your device version; the controller assignments are not interchangeable.

• MIDI note control, Program Change, modulation and pitch bend.
• Real-time access to more than 40 OB-Xa parameters.
• Edit, copy, paste and store functions.
• 56 additional ROM presets and 56 user memories.
• SysEx backup and restore, plus parameter feedback.

Installation and power

Connect the magicBox to the COMPUTER INTERFACE port on the rear of the OB-Xa. The standard installation requires no internal modification to the synthesizer.

The OB-Xa-specific interface documented here requires an external 5–9 V DC supply, centre positive (+), not included. For another magicBox version, follow that version’s power specifications.

Alternatively, the OB-Xa power modification (PDF) allows power to be supplied from the synthesizer. This optional modification is separate from the standard external installation.

MIDI connections

Check the connectors on your magicBox:

• One combined MIDI IN/OUT socket: older devices require a MIDI split cable for a two-way connection.
• Separate MIDI IN and MIDI OUT sockets: use two MIDI cables; a split cable is not required for parameter feedback.

MIDI connection diagram (PDF) · Split-cable wiring (PDF)

Downloads

OB-Xa-specific magicBox

• OB-Xa BCR2000 configuration (ZIP)
• OB-Xa MIDIcontrol manual (PDF)
• OB-Xa MIDI controller tables below

All-in-one magicBox3

• magicBox3 controller setup files (ZIP)
• magicBox3 MIDI implementation chart

Parameter feedback

After a MIDI Program Change or Program Load, the magicBox sends the current parameter values from MIDI OUT. A compatible controller, such as the BCR2000 or Touch-OSC, can update its controls and displays to match the loaded sound. TB-MIDI-Stuff is also supported.

For the two-way BCR2000 MIDI connection shown above, use standalone mode S-3 to avoid MIDI feedback loops.

BCR2000 setup

1. Hold EDIT and press STORE to enter the global settings.
2. Use the first encoder in the top row to choose the transfer connection: U for USB or S for MIDI. For the two-way MIDI connection to the magicBox, select S-3.
3. Use the fifth encoder in the top row to set the SysEx device ID to 1. Press EXIT.
4. Send the OB-Xa BCR2000 setup SysEx file via the selected connection. The display shows incoming data as a circular animation.
5. The received setup is held temporarily. Press STORE, choose one of the 32 preset locations with the PRESET cursor keys, then press STORE again.

Load, edit and save an OB-Xa sound

1. Use the bottom-left encoder to select a preset from 1 to 56. For example, select preset 33 and press LOAD.
2. Edit the loaded OB-Xa sound with the controller.
3. Use the bottom-right encoder to select a user memory from 1 to 56, then press SAVE.

Copy, edit and save demonstration (shown with an OB-SX)

Back up and restore user memories

Send CC 107 with value 127 to transmit all 56 user memories as a SysEx dump from MIDI OUT. Save the dump with your MIDI software.

Send the saved SysEx file back to the magicBox to restore it. This replaces all current user memories.

OB-Xa MIDI controller reference

These assignments belong to the OB-Xa-specific magicBox documented on this page. The all-in-one magicBox3 uses the separate chart linked above. In the switch table, ch denotes the MIDI channel.

OB-Xa controls

OB-Xa switches

Additional controls

For CC 120 on MIDI channel 15: 0 = Omni mode.

Program change 1-112