Oberheim Matrix-6 User manual

Oberheim
Matrix
MatrixMatrix
Matrix-
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-6
66
6
6-Vorce Polyphonic MIDI Synthesizer
SERVICE MANUAL
Preliminary Edition - February 1986
1996 OBERHEIM • A Division of E.C.C. Development Corporation
11650 Olympic Boulevard, Los Angeles, California 90064
AlI Rights Reserved. Reproduction in Whole or In Parts is prohibited
without Permission. Oberheim, The Oberheim Logo, MATRIX-6,
MATRIX-12, XPANDER, Xk, OB-8, DSX, DMX, and DX are Trademark of
E.C.C. Development Corporation
PDF-Version by Rolf Meurer 40211 Düsseldorf Germany 2012

MATRIX-6 SERVICE MANUAL
PRELIMINARY EDITION – February, 1986
CALIBRATION
1. TUNE - While in MASTER EDIT, pressing the B button puts the MATRIX-6 into
Auto Tune. The cycle takes approximately two to three seconds to complete,
during which time the display reads "TUNING...", While In TUNE mode, the
processor is tuning the MATR-X-6's three High Frequency Oscillators (HFOs).
2. CALIBRATE - While in MASTER EDIT, pressing the A button puts the
MATRIX-6 into Parameter Select mode. While in this mode, call up parameter
52 and the display should read "52 CALIBRATE ". Now press the D button.
This will put the MATRIX-6 into VALUE mode and the display will read
"READY?
".
Press the YES button on the Keypad - the display will blank out
during the Calibration routine. When the process is finished, the display will
return to read "52 CALIBRATE".
The CALIBRATE function calibrates the three HFOs as well as the VCF
Frequency, Pulse Widths, Resonance amount and VCA2 level on each voice.
if the MATRIX-6 encounters any problems while tuning the voices, it will
display which voice and the section of that voice that is having the problem. To
display tuning failures enter CALIBRATE mode and, with the display blank,
press and hold the C button until the display returns to "52 CALIBRATE",
If the MATRlX-6 tunes all six voices without encountering any problems, the
display will remain blank during the tuning process. When problems are
encountered, the display will indicate which of the four sections of the tuning
process and the voice or voices that are bad. Failures in any of the four sections
of the tuning process are displayed with the following messages:
B A D OS C * *
BADWAVE **
BADRES **
BAD VCF **
for problems with the HFOs.
for oscillator waveform problems.
for resonance problems.
for filter problems.
The two stars in each message represent a two digit number that indicates which
voice or voices have failed that section of the Calibration, The number is a
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decimal equivalent of a binary number, with each digit in the binary number
corresponding to a particular voice. For example, if the display reads " BAD OSC 63 ", it
would be broken down like this:
Decimal number - 63
Value of binary digits - 32 16 6 4 2 1
Binary equivalent - 1 1 1 1 1 1
Corresponding bad voices - V6 V5 V4 V3 V2 V1
So if the display reads "BAD OSC 63" this means that all six of the voices
have failed the Oscillator section of the tuning. Now if the display reads "BAD
WAVE 24*, it would be broken down like this:
Decimal number - 24
Value of binary digits 32 16 6 4 2 1
Binary equivalent- 0 1 1 0 0 0
Corresponding bad voices - — V5 V4 — — —
With “BAD WAVE 24 “ Voices four and five have failed the waveform Calibration.
Note: When trying to display the tuning failures, be sure to watch the display,
because the failure displays are only shown for a short time.
When tuning failures are encountered, run the CALIBRATE function two more
times, If there are no more failures after the third attempt, Tuning is OK. This will
happen most often when the unit is cold.
3, DAC CALIBRATION - To enter this mode, the MATRIX-6 must be in
MASTER EDIT parameter select mode. With parameter "52 CALIBRATE"
displayed. first press and hold the D button. Next, press and hold the C button
then press and hold the B button. The MATRIX-6 is now in DAC CALIBRATJOIM
mode and all three held buttons can be released. the display should read
"TUNING...'.
Caution: Be careful not to short any pins when zeroing the DAC.
With a DVM in the millivolt range, set the DAC output to 0.000 volts. The DAC output is
measured al pin 6 of U712 on the Voice board. Connect the DVM ground to the
ground leg of C13 (the leg toward rear of unit). C13 is directly behind U704. Adjust
the DAC output to zero by turning the trimmer located directly behind U712.
To exit DAC CALIBRATION mode press the MASTER button.
Note: After zeroing the DAC, the MASTER EDIT parameter number
"
52 CALIBRATE" must be performed.
4. HFO CALIBRATION - To enter the High Frequency Oscillator Calibration
mode, the MATRIX-6 must be in the MASTER EDIT parameter select mode.
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Select parameter number "52 CALIBRATE". Now press and hold the C button, then
press and hold the B button. The MATRIX-6 is now In HFO CALIBRATION mode and the
two buttons can be released.
Caution: when adjusting the coils of the HFO’s take care not to damage the very
fragile core.
When adjusting HFOs, be sure to remove adjusting tool from the core of the coil
before taking the frequency measure.
There are three High Frequency Oscillators which need lo be adjusted when Calibrating
HFO's. The adjustments are made. First at L2, then L3 and last L1 Use a Frequency
Counter to set the frequency of all three Oscillators between 3.500 and 3.505 Mega HZ.
After 11 is set, the frequency of L2 and L3 should be double checked to make sure they
have not changed,
To adjust L2 connect Frequency Counter to pin 14 of U732.
To adjust L3 connect Frequency Counter to pin 14 of U 733.
To adjust L1 connect Frequency Counter to pin 14 of U736.
Alter adjusting all three HFOs, exit HFO CALIBFRATION mode by pressing MASTER
Button.
Note: After Calibrating the HFOs, the MASTER EDIT parameter "52
CALIBRATE" must be preformed.
5. PROCESSOR RESET & INTIALIZE - First, make sure the AC power is turned off.
Press and hold the red STORE button. Turn the AC power on and
the display should have one or two characters flickering in the display. Now release the
STORE button and the Display will go blank for a few seconds.When the display resets,
it will recall patch number "00", although the unit will display patch "00", it will be playing
the initialized patch.
POWER SUPPLY
VOLTAGE TOLERANCES J03 PIN #
-5 +/- 200mv
1
+5A
+/- 200mv
3,4
+5B
+/- 200mv
5,6
+12
+/- 500mv
7,8
-12
+/- 500mv 9,10
-42
-41v to -45v n / a * *
* J03 is the connector located on the Power Supply board.
** The -42 volt supply is measured on the no component side of the Display Board, at
the point labelled
"
-42", located directly behind the fluorescent display.
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