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The MASTER Section of the Matrix-12 permits the selection of the GLOBAL functions - the overall functions of the synthesizer that are not programmable per Patch - that affect the entire instrument regardless of what Page is selected later.


This knob simply controls the overall audio output level of the Matrix-12. When it is fully counter-clockwise, the mixed AUDIO OUT jacks - LEFT, MONO and RIGHT - are effectively turned off. Full volume is achieved when the control is turned fully clockwise.

The VOLUME knob simultaneously controls the output of the synthesizer through the LEFT, MONO, and RIGHT AUDIO OUT jacks on the Matrix-12's back panel. It also controls the volume output of the Matrix-12 in CASSETTE MODE as a monitor during data transfer.

If you have your Matrix-12 retro-fitted with the optional individual Voice Outputs, the master VOLUME control has no effect on their output level.


The TUNE PAGE key selects the Matrix-12's functions that affect its overall tuning. Pressing this button displays the available Tuning parameters:


Upper Display
The UPPER window displays the Matrix-12's Audio-Tune parameters. In addition to the standard oscillator tuning (displayed as VCOS), the Tune Page in the Matrix-12 permits the calibration and scaling of several parameters not tuned on other synthesizers. PW selects the calibration of the Voices' Pulse Widths to insure uniformity among the 24 oscillators. RES calibrates the Resonance level of each the 12 Voltage Controlled Filters (one per Voice). VCF tunes the frequency of each Filter. VCA, like PW, insures the uniformity of the final VCA of each Voice. This calibration makes the volume level of each of the 12 Voices equal.

To tune an individual parameter, press the button directly below its name in the display. If RES is selected, VCF is also selected automatically. This is because the reliability of the VCF tuning is dependent upon the scaling of the Resonance parameter. It is logical, then, to tune them together if RES is selected.

To tune all of the parameters, press ALL. The Matrix-12 will proceed through its entire Auto-Tune cycle, which takes about 90 seconds to complete.

1. During the Auto-Tune routine, the message "TUNING" will appear on the LOWER display directly beneath the parameter being tuned. When the Matrix-12's processor is finished all 12 Voices for a given parameter, the message "PASS" will appear on the LOWER display directly beneath its name.


2. If, for any reason, the Matrix-12 cannot successfully tune all 12 Voices for one of the parameters, the message "FAIL" will be displayed in the LOWER window directly beneath the parameter's name. Pressing PAGE 2 will display the Voices that failed for that parameter. The first Voice out of the 12 to fail is displayed and turning the knob directly beneath that parameter will display the other Voices (if any) that have failed.

Failed Voices is a rare occurrence and may happen if the Matrix-12 is used in an environment that has extremes in temperature and/or humidity. You may also experience some Voice failing on occasion if the matrix-12 is tuned immediately after you first power it on, due to that fact that the synthesizer requires approximately 30 minutes of warm-up time in order to temperature-stabilize. If you get consistent Voice failing after several Auto-Tune attempts, your Matrix-12 may need servicing.

3. After a successful Auto-Tune, pressing TUNE PAGE returns the front panel back to its original displays.

Lower Display
The LOWER display permits the operation of the synthesizer's three Master Tune functions. These parameters are not programmable per Patch, but will remain set in Global memory as they are until you change them, even if you call up another Page, turn the Matrix-12 off, etc.

This is Matrix-12's Master Fine Tune adjustment, used to tune the entire synthesizer as a whole to other instruments. The rotary control directly beneath the number readout is used to make this adjustment. Its range is from -63 to +63 which represents a quarter-tone sharp or flat. A setting of 0 is A=440Hz.

These two parameters are the master Octave Switching controls. Use these buttons directly beneath their displays to operate these functions. The range of this function is five octaves. -OCT will transpose the Matrix-12 as a whole down a maximum of three octaves in 1-octave increments; +OCT transposes up a maximum of two octaves in 1-octave increments.

When these two controls are used, a value of 12 will be added or subtracted from the value shown in the TRANSPOSE control in the adjacent display segment until the upper or lower limits of transpose are reached. See its description below.

This is the Matrix-12's master Transpose control which transposes the entire synthesizer in semi-tone increments. Its range is the same as the Master Octave Switching controls: three octaves down or two octaves up. The display will indicate the number of semi-tones of transposition numerically from -36 to +24. Use the knob directly beneath the number display to adjust this parameter.


The Master Page is the heart of the matrix-12's performance control. Grasping the operational concepts behind the design of this Page will enable you to quickly and easily set up the synthesizer's master functions.


The following tables summarize the parameters of the MASTER PAGE. The Upper and Lower Display functions in Page 1 will be discussed in detail at the end of this summary.

Page 1 - Global control for SINGLE PATCH Mode and MULTI PATCH Mode:

Upper Display

This is the Page where all existing Single and Multi Patches can be arranged in a logical "link" for live performance. Once a CHAIN has been written, the patches can be stepped through by using a footswitch plugged into the Matrix-12's back panel ADVANCE CHAIN jack or by using the "+" and "-" on the Keypad.

The Matrix-12's extensive MIDI assignments are selected in this Page which enable the synthesizer to act as either a Master or a Slave in a MIDI system - r both, at the same time.

A Page of miscellaneous parameters that include Velocity Scale and Velocity Sensitivity adjustments as well as a Page 2 of controls for setting the Matrix-12's Levers, PEDALs and EXT TRI (External Trigger) polarities.

"Cassette Interface" - provides a method of saving and retrieving the data you have programmed into the Matrix-12 using standard audio cassette tape. The entire contents of the synthesizer's memory is saved to tape and can be loaded back into the Matrix-12 in its entirety or selectively. A function called CHECK is also provided to verify the tape and identify any errors.

Lower Display

Parameters that provide Global control for SINGLE PATCH Mode. These parameters are Programmable for each individual MULTI Patch (in MULTI PATCH Mode, titles are printed in grey on the front panel).

These parameters enable the "placement" of the Voices' audio outputs in the stereo field from LEFT to RIGHT, similar to using a mixing console.

"Vibrato" - provides the necessary parameters to obtain some very elaborate Vibrato settings.

"Voice Assignment" - sets the playing control source for each Voice, either polyphonically or monophonically from the Keyboard, directly MIDI IN control or both.

The six ZONEs are selected from this parameter and work in conjunction with VASSIGN in setting up specific areas of the Keyboard or the MIDI Note Range that will play the Voices polyphonically.

Page 2 - Global control for SINGLE PATCH Mode and MULTI PATCH Mode:

When selected, displays seven Test Routines used to calibrate and test the matrix-12. This Sub-Page is provided to assist in the production of the synthesizer and in servicing malfunctions in the field and are not necessary for normal use of the instrument. Consult the Matrix-12 SERVICE MANUAL for more information.

This parameter provides a visual means to examine which Voice or Voices, if any, that have been failed by Auto-Tune, or if it is desired that a Voice or any number of Voices be manually defeated. When selected OFF, the Voice will ignore any Keyboard or MIDI IN commands to play until it is re-enabled. The ON/OFF status of the Voices is retained in memory when the Matrix-12 is powered off.

When selected, this parameter displays the current Software Version of the matrix-12. The three micro-processors inside your Matrix-12 handle all the calculations required to perform the various functions of the synthesizer. The processors work according to a pre-programmed set of operating instructions called "software". Software can be altered at any time by Oberheim to reflect improvements or additions to these operating instructions. Everytime software is revised, a new index number is assigned to the revision. This is known as the Software VERSION.

The Version of your Matrix-12 can be displayed at any time simply by entering this Parameter. When entered, the index numbers of the matrix-12's operating software will be displayed. Pressing PAGE 2 displays the software's Copyright Notice. Software Updates issued by ECC/Oberheim can be retrofitted to any Matrix-12.


The CHAIN Page provides a very useful performance feature that permits you to arrange the SINGLE and MULTI Patches in a preprogrammed order. Once you have determined the order in which you want the Patches to be, for a live set as an example, they can be stepped through with the "+" and "-" buttons on the Keypad or by using a footswitch inserted into the ADVANCE CHAIN input on the Matrix-12's back panel. Thus, CHAIN permits you to re-arrange your Patches as often as needed without having to continually re-program the Patch order in SINGLE and MULTI Patch Modes. In addition, CHAIN also permits switching to any desired Patch Number with the one command, even if you are selecting between SINGLE and MULTI Patches.


This parameter simply turns CHAIN on or off, with a third option of SLAVE.

When selected OFF, the CHAIN Page is defeated and the Patch Number select operation of the Keypad is normal. A footswitch plugged into ADVANCE CHAIN on the back panel will advance through the Patch Numbers - the same operation as the "+" button - when CHAIN is OFF.

When ON, CHAIN is enabled and the Patch List that you have arranged can be stepped through with the ADVANCE CHAIN footswitch or with the "+" and "-" switches on the Keypad. You can still select among the Patches with the 0 through 9 buttons on the Keypad as normal, as well as switch between SINGLE and MULTI Patch Modes.

It should be mentioned at this point that there are two distinct functional differences between ADVANCE CHAIN and Keypad operation of CHAIN. First, the ADVANCE CHAIN footswitch steps through the CHAIN in ascending order only. Using the "+" or "-" keys permit you to advance (+) as well as reverse (-). Secondly, when using the footswitch, the CHAIN will stop when Step 99 is reached. The "+" and "-" buttons permit looping of the CHAIN.

When SLAVE is selected, the operation of the CHAIN Page does not change but simply allows the PROGRAMMER to display the current Patch in each STEP Number when Knob #3 or the X SELECT buttons are used to select STEP Numbers.


This parameter selects among the 100 available Patch Numbers in the CHAIN numbered 00 through 99. Knob #3 is used to advance or reverse through the Patch Numbers in order to program the CHAIN or simply examine its contents. Also, if the button beneath the STEP Number is pressed, the number in the display becomes underlined and you can select among the 100 Steps using the X SELECT buttons.

As mentioned above, if SLAVE is selected in the ENABLE parameter, the PROGRAMMER window will also display the current Patch selected in each STEP Number.


This parameter is used to select a SINGLE Patch or a MULTI Patch to be programmed in the current STEP. The button beneath the MODE display or Knob #5 can be used to select between a SINGLE Patch or a MULTI Patch.


This parameter is used to select the desired Patch Number for the current STEP from 00 to 99. If the current MODE is a SINGLE Patch, the number selected will be the SINGLE Patch Number for that STEP. If the current MODE is a MULTI Patch, the number selected will be the MULTI Patch Number for that STEP.

Knob #5 is used to advance or reverse through the Patch Numbers in order to select the PATCH. Also, if the button beneath the PATCH Number is pressed, the number in the display becomes underlined and you can select among the 100 Patches using the X SELECT buttons.

MIDI Patch Changes -
Operation with another Matrix-12 or the Oberheim Xpander

When using the MIDI Patch Change function, both Oberheim instruments must have SYSTEMX (System Exclusive) and PATCH in the MIDI ENABLES Sub-Page in order for the Slave Oberheim to respond to the Master's switching between SINGLE Patch Mode and MULTI Patch Mode.

SYSTEMX must also be enabled on both the Master and Slave Oberheim instruments for MIDI Patch Changes to occur when using the ADVANCE CHAIN footswitch or the "+" and "-" buttons on the Master Oberheim.

If CHAIN is being used on the Master Oberheim, it will send MIDI Patch Numbers to the Slave Oberheim on the BASIC CHANNEL when the ADVANCE CHAIN footswitch or the "+" and "_" buttons are used. Just be sure that PATCH and SYSTEMX are enabled for both instruments. If SYSTEMX is disabled on either the Master or the Slave Oberheim, the Slave will not respond at all to Patch Changes made from the Master in CHAIN.

MIDI Patch Changes -
Operation with Other Instruments

Patch Changes made on the Matrix-12 in CHAIN are not transmitted via MIDI unless System Exclusive is enabled in the MIDI ENABLES Sub-Pages. Since the receiving instrument must be another Oberheim - or one that has the Oberheim System Exclusive code programmed, Patch Changes made in CHAIN will not be recognized by other manufacturers' equipment.


The extensive MIDI assignments of the Matrix-12 are selected in this Page.

"MIDI" is the acronym for Musical Instrument Digital Interface. MIDI is a universally accepted system of digital communication that allows you to hook up your Matrix-12 to other devices - synthesizers, sequencers, drum machines, computers, etc. - as long as they are also equipped with a MIDI interface. MIDI makes it possible to connect instruments made by different manufacturers.

Because your Matrix-12 uses an internal computer (called a microprocessor"), it is able to communicate through MIDI to other microprocessor based devices that have this interface. MIDI, then, is a digital language that enables two or more MIDI-equipped instruments to "talk" to each other.

In the MIDI Sub-Pages, you are able to determine when and what kind of communication takes place and how it will occur. MIDI communication is transmitted and received, and this occurs through channels - much the same as radio or television, but using cables instead of antennas. Connecting two or more MIDI devices together constitutes a MIDI "system".

MIDI Communication
With the exception of just two MIDI functions - individual Voice control from MIDI IN in VASSIGN and MIDI Input selection in ZONE - programming the MIDI control in the Matrix-12 is accomplished in the Sub-Pages of the MIDI Page.

The MIDI parameters selected and programmed in these Sub-Pages are Global. This is true for both SINGLE and mULTI Patches.

MIDI communication is divided into several categories. For our purposes in this section of the manual, we will be concerned with three of these sub-groups:


Notes played on one instrument are played on the other(s) as well as VELOCITY and RELEASE VELOCITY.


LEVER1 (or a Pitch Wheel from a Master connected to the Matrix-12's MIDI IN) and LEVER2 (or a Vibrato Wheel), PEDAL1 (normally Volume) PEDAL2 (normally Sustain) and PRESSURE (After-Touch) used on one will modulate the others in the MIDI system.


The remaining performance control commonly used in MIDI communication, the PATCH CHANGE command, is treated separately by the Matrix-12. The ensuring discussion clarify this.

The Matrix-12 enables you to set 14 MIDI assignments grouped into 6 MIDI headings described in the following pages. These six headings are:



Otherwise referred to as the "Basic Channel", this parameter selects the transmitting and receiving MIDI Channel for the Matrix-12. VALUE X selects any one of the available MIDI Channels numbered 1 through 16.

The main thing to keep in mind is that if the master instrument in a MIDI system is transmitting on a certain channel, the receiving instruments must also be set to that channel, or be in OMNI Mode, for MIDI communication to take place. In the Matrix-12, these "receiving instruments" are the 12 Voices. Since they can be controlled independently, each of the Matrix-12's Voices can be regarded as an "instrument". If the Voices are assigned to one or more Zones to be played polyphonically, each ZONE is a "receiving instrument".

The Basic Channels are concerned primarily with transmitting and receiving Notes and Controllers. There are, however, a few details you must observe:


When MIDI IN is used, the Matrix-12 is considered a SLAVE and will receive Notes and Controllers on the MIDI Channel that you specify in VASSIGN or ZONE. Thus, the MIDI Channel(s) selected for the Voices in VASSIGN or ZONE will be used by the MATRIX-12 as the "Basic Channel(s)" for those Voices assigned to them.

PATCH CHANGES, on the other hand (because they are treated separately) are received on the Basic Channel that has been set in this parameter and not on the ZONE's channel.

As an example, assume that the basic Channel of the Matrix-12 is set in this parameter to 2. If all 12 Voices are assigned to ZONE 3 and ZONE 3's CHANNEL setting is Channel 6, Channel 6 is the one that will be used for Notes and Controllers but PATCH CHANGES will still be received on Channel 2. Thus, Patch Changes are global commands and Notes and Controllers are tied in to the ZONES or individual channel settings in VASSIGN.

If the CHANNEL of the ZONE hat is being used to receive is set to OMNI, it will receive Notes and Controllers on all channels. If the ZONE is set to a single MIDI Channel, that channel is the one used for receiving Notes and Controllers and Patch Change commands will still only take place on the Basic Channel.

The Master controller that you are using to drive the Matrix-12 must be set to transmit on the Zone's channel as well. The exception to this (and this is an important one) is that if OMNI MODE is turned ON in the ZONE, the Matrix-12 will receive Notes and Controllers on any MIDI channel for the Voices assigned to that particular ZONE. The Master instrument can be set to transmit on any MIDI channel and its Notes and Controllers will be received by the ZONE at all times when it is in OMNI MODE. Patch Change commands are still received on the Basic Channel and is not dependent on the Zone's channel setting.



When MIDI OUT is used, the Matrix-12 is considered the Master in the MIDI system and handles MIDI communication the same as when receiving. It will transmit its own Notes and Controllers to other slaves in the system on the Zone's channels. If OMNI is selected as a Zone's CHANNEL, notes and controllers will be sent on the Matrix-12's Basic Channel. Patch Changes will be transmitted on the basic Channel only. If the Matrix-12 is a Slave, MIDI OUT can still be used as well. Playing notes on its Keyboard and using its controllers will control another instrument as a Slave.

When the Matrix-12 is a Slave, if MIDI OUT is used and MIDI parameter ECHO is selected in the ENABLES Sub-Page, the Matrix-12 will transmit MIDI Notes and Controllers coming from the Master controller as well as its own MIDI on whatever you select as the channel settings for the active ZONES. If an active ZONE has its CHANNEL parameter set to OMNI, Notes and Controllers are transmitted on the matrix-12's Basic Channel. Even though the Matrix-12 is technically a Slave in the system - due to the fact that it as another Master when its MIDI OUT and MIDI ECHO are used together.

If the CHANNEL of the ZONE that is being used to transmit is se to OMNI, it will transmit Notes and Controllers on the Matrix-12's Basic Channel. If the Zone is set to a single MIDI Channel, that channel is the one used for transmitting and Patch Change commands will still take place on the Basic Channel. ECHO permits the combining of MIDI information plus the Matrix-12's own MIDI data and transmitting it via MIDI OUT.



When the Matrix-12 is Slaved and MIDI THRU is used instead of MIDI OUT, it will only respond as a Slave in your MIDI system and will simply pass information received from its MIDI IN to other slave instruments in the system, unaffected by any MIDI processing going on inside the matrix-12 itself. The Matrix-12 can still transmit information from its MIDI OUT port but this information does not go out MIDI THRU - just the information coming from the Master

A Word About OMNI MODE
As we mentioned above, OMNI MODE is turned ON or OFF in the ZONE Pages. Although we will cover this in detail when we discuss Zones, it is a good idea that we touch on OMNI Mode here briefly.

When OMNI is ON for a particular ZONE, the Matrix-12 will receive MIDI Notes and Controllers from the Master instrument on all 16 Channels plus special MIDI data of TUNE REQUEST and SYSTEM EXCLUSIVE messages on that ZONE. These messages are controlled in the Master MIDI ENABLES Page only, not by OMNI Mode itself. "OMNI" simply means that the ZONE will ignore all channel numbers in deciding whether to use a given MIDI event.

As a rule of thumb, keep in mind that all MIDI information except Tune, Active Sense, MIDI Timing Clock, Song Position Pointer and System Exclusive data are sent on one of the MIDI 1 through 16 Channels.

When a single MIDI Channel is selected for a particular ZONE, OMNI MODE is thus turned OFF. The Matrix-12 will transmit and receive MIDI Notes and Controllers on that MIDI Channel only and the Basic Channel is used simply to transmit Patch Changes. The ZONE will ignore MIDI information coming from any other channel. Selecting a single MIDI Channel turns OMNI off, and the ZONE is set to receive Notes polyphonically from that single MIDI Channel.