SYNTHS / OBERHEIM / Oberheim Xpander (300 dpi)


The Oberheim Xpander is a beautiful analog synthesizer with some amazing features for its time.

The Oberheim Xpander has three large screens to help in navigating the powerful synthesizer

Above : Right Side of the Oberheim Xpander

Below : Close up views of the navigation menus




The Oberheim Xpander has a lot of connections available

Oberheim Xpander MIDI connections






TIPS for the Oberheim Xpander

OS Versions and Tuning

Above : The most Current OS versions are Main Processor Software 1.2, Voice 1.4, and cassette 1.0

Above tune screen . Press the ALL switch on the right to tune everything

To get to this screen Press the Tune Page Button near the Master Volume

then Press ALL. It will take a little over a minute and if all goes well the screen below appears

Above after running tune ALL responds with PASS for each section tested



Back it Up

To back up over MIDI with sysex.

1. Enable sysex on Xpander. Press MASTER then MIDI then ENABLES

Set SYSTEMX and CONTROL to have an underline under them, turning them ON

2. Set SYSEx recorder to record. Press MASTER then MIDI then SEND

3. Under Destination Patch turn the knob to the left pass 0 to ALL and hit START

It takes about a minute and I ended up with a 51.0 KB file

To transfer in , just play the SYSEX file back with the above Enables ON (Step 1 above)


DOCS for the Oberheim Xpander Here

Xpander 4

Above Open wide showing the insides of the Oberheim Xpander

Above : top right is the main processor and bottom right is the power supply

Above the Oberheim Xpander pot board that holds all the front panel controls

Above : Main processor board U5 thru U8 are the Version 1.2 processor ROM

A little closer look at the maim processor in the Oberheim Xpander

HITACHI HD68B09P Microprocessor


Above the power supply


U912 and U914 are the voice Processor ROM where the OS resides for the Voice Board

Below is a close up of the microprocessor

HITACHI HD68B09P Microprocessor this is the voice Controller

----------------|----Voice 1--------|--- Voice 2 --------|----- Voice 3------|------ Voice 4 -----|---- Voice 5-------|------ Voice 6----|

Above : The voice board all 6 voices left to right

Above : This is one voice, starting below at the left edge is the filter section

CEM 3372 and U317, U316,U314, U313 form all the possible filter types

Filter pin out and basic diagram

Oscillator Section


SYNTHS / OBERHEIM / Oberheim Xpander (300 dpi)

other synthesizers-E-mu Systems, Sequential Circuits

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