Oberheim Matrix-6R

DCO

Digital Controlled Oscillators (DCO) in Matrix-6 are considered to be true analog. But rather than maintain stability for 12 oscillators, two for each of the six voices it only has 3 analog oscillators in total, all with digital fine tuning from U713 (MP7621 12-bit dac) / U705(4051 mux) and U738, 739, U740 (TL068 voltage follower). Rather than thinking of them as audio oscillators they are more like high speed clock sources.

Digital control continues with these three clocks going to four pre-scale dividers U732,U733,U736,U737 (SN74LS161) where it generate 4 programmable clock signals.
Pre-scalers then feeds four programmable interval timers U727,U728,U729,U730 (82C54). From here the synth now has 12 pitch signals (clocks) grouped as CLKA1-6 and CLKB1-6 feeding the two waveform converter inputs on each of the six Curtis CEM3396.

Speculating here, but the odd numbers of clock oscillators, pre-scale chips and uneven seeding of 8254 are probably to do with workarounds to accomplish timely updating of pitch data combined with low parts count.

MODULATION

The real power of the Matrix synth series where its routing matrix. Matrix-6 has 18 predefined modulation routings plus 10 slots to configure any combination from 20 sourches to 32 destinations.

A quick analyze reveals that all sources and destination nodes are already in the digital domain. Most of this modulation matrix then seems to exist in software.

32C20 should give somethining like 225 792 840 unique routing combinations. That's a quantum leap from any number of predefined modulation routings found in other synthesizers in 1986.

MATRIX MODULATION
-------------------------
SOURCES
-------------------------
00 DELETE MODULATION
01 ENVELOPE 1
02 ENVELOPE 2
03 ENVELOPE 3
04 LFO 1
05 LFO 2
06 VIBRATO
07 RAMP 1
08 RAMP 2
09 KEYBOARD
10 PORTAMENTO
11 TRACKING GENERATOR
12 KEYBOARD GATE
13 VELOCITY
14 RELEASE VELOCITY
15 PRESSURE
16 PEDAL 1
17 PEDAL 2
18 LEVER 1
19 LEVER 2
20 LEVER 3 = LEVER 2 REVERSE  
 
-------------------------
DESTINATIONS
-------------------------
00 DELETE MODULATION
01 DCO 1 FREQUENCY
02 DCO 1 PULSE WIDTH
03 D00 1 WAVE SHAPE
04 D00 2 FREQUENCY
05 DCO 2 PULSE WIDTH
06 DCO 2 WAVE SHAPE
07 DC0 1 - DCO 2 MIX
08 VCF FM BY DC0 1
09 VCF FREQUENCY
10 VCF RESONANCE
11 VGA 1 VOLUME
12 VGA 2 VOLUME
13 ENV 1 DELAY
14 ENV 1 ATTACK
15 ENV 1 DECAY
16 ENV 1 RELEASE
17 ENV 1 AMPLITUDE
18 ENV 2 DELAY
19 ENV 2 ATTACK
20 ENV 2 DECAY
21 ENV 2 RELEASE
22 ENV 2 AMPLITUDE
23 ENV 3 DELAY
24 ENV 3 ATTACK
25 ENV 3 DECAY
26 ENV 3 RELEASE
27 ENV 3 AMPLITUDE
28 LFO 1 SPEED
29 LFO 1 AMPLITUDE
30 LFO 2 SPEED
31 LFO 2 AMPLITUDE
32 PORTAMENTO RATE


PATCH EDIT
-------------------------
DCO 1-2
-------------------------
00-10 FREQUENCY
01-11 FREO MOD BY LF01
02-12 SYNC
03-13 PULSE WIDTH
04-14 PW MOD BY LFO2
05-15 WAVE SHAPE
06-16 WAVE SHAPE
07-17 LEVERS
08-18 KEYBOARD/PORTAMENTO
09-19 KEY CLICK

-------------------------
VCF/VCA
-------------------------
20 BALANCE
21 FREQUENCY
22 FREO MOD BY ENV1
23 FREO MOD BY PRESSURE
24 RESONANCE
25 LEVERS
26 KEYBOARD/PORTAMENTO
27 VCA 1 VOLUME
28 VCA 1 MOD BY VELOCITY
29 VCA 2 MOD BY ENV2 

-------------------------
FM/TRACK
-------------------------
30 VCF FM AMOUNT
31 FM MOD BY ENV3
32 FM MOD BY PRESSURE
33 TRACK INPUT
34 TRACK POINT 1 
35 TRACK POINT 2
36 TRACK POINT 3
37 TRACK POINT 4
38 TRACK POINT 5

-------------------------
RAMP/PORTAMENTO
-------------------------
40 RAMP 1 RATE
41 RAMP 1 TRIGGER
42 RAMP 2 RATE
43 RAMP 2 TRIGGER
44 PORTAMENTO RATE
45 PORT MOD BY VELOCITY
46 PORTAMENTO MODE
47 LEGATO PORTAMENTO
48 KEYBOARD MODE

-------------------------
ENV 1-2-3
-------------------------
50-60-70 DELAY
51-61-71 ATTACK
52-62-72 DECAY
53-63-73 SUSTAIN
54-64-74 RELEASE
55-65-75 AMPLITUDE
56-66-76 AMP MODE VELOCITY
57-67-77 TRIGGER MODE
58-68-78 ENVELOPE MODE
59-69-79 LFO 1 TRIGGER

-------------------------
LFO 1
-------------------------
80 SPEED
81 SPEED MOD BY PRESSURE
82 WAVEFORM
83 RETRIGGER POINT
84 AMPLITUDE
85 AMP MODE BY RAMP 1
86 TRIGGER MODE
87 LAG
88 SAMPLE INPUT

-------------------------
LFO 2
-------------------------
80 SPEED
81 SPEED MOD BY KEYBOARD
82 WAVEFORM
83 RETRIGGER POINT
84 AMPLITUDE
85 AMP MODE BY RAMP 2
86 TRIGGER MODE
87 LAG
88 SAMPLE INPUT

-/\/\/\/\/\/\/\/\/\/\/\/\-

MASTER EDIT
-------------------------
MIDI
-------------------------
00 BASIC CHANNEL
01 OMNI MODE
02 CONTROLLERS
03 PATCH CHANGES
04 SYSTEM EXCLUSIVE
05 LOCAL CONTROL
06 PEDAL 1 SELECT
07 PEDAL 2 SELECT
08 LEVER 2 SELECT
09 LEVER 3 SELECT
10 SEND PATCH
11 SEND ALL
12 MIDI ECHO
13 SPILL OVER
14 ACTIVE SENSE
15 PATCH MAP
16 PATCH MAP EDIT

-------------------------
CASSETTE
-------------------------
20 STORE ALL
21 CHECK ALL
22 LOAD ALL
23 SELECTIV LOAD

-------------------------
VIBRATO
-------------------------
30 SPEED
31 WAVEFORM
32 AMPLITUDE
33 SPEED MOD SOURCE
34 SPEED MOD AMOUNT
35 AMP MOD SOURCE
36 AMP MOD AMOUNT

-------------------------
MISC
-------------------------
50 EDIT RECALL
51 PATCH INITIALIZE
52 CALIBRATE
53 DISPLAY BRIGHTNESS
54 SOFTWARE VERSION
55 MASTER TUNE
56 STEREO OUTPUT
57 SWITCH QUICK

-------------------------
SPLIT EDIT
-------------------------
0 LEFT UPPER LIMIT
1 LEFT TRANSPOSE
2 LEFT MIDI OUTPUT
3 RIGHT LOWER LIMIT
4 RIGHT TRANSPOSE
5 RIGHT MIDI OUTPUT
6 LEFT-RIGHT BALANCE
7 VOICE/ZONE SELECT 
			

R. Grieb (Bob) has a new firmware with faster MIDI. You will also find info on the remote connector and how-to replace the screen with LCD/OLED.
http://www.tauntek.com/synthesizerinfo.htm