No announcement yet.

GEAR: Matrix 6 and Matrix 6r

  • Filter
  • Time
  • Show
Clear All
new posts

  • GEAR: Matrix 6 and Matrix 6r

    Repair: Oberheim Matrix 6 / 6r /1000

    SO, any of you got a Matrix 6? A 6r will do.. And to a lesser extent, but the same problems, a Matrix 1000? I do.. Got it in 1990 from a repair shop that could not fix it.. It was rusted and abused, so i had to bypass the volume slider years ago.. But, it always had the MAD SYNTH problem.. That is: the machine would crash randomly, and only a good beating and reset (power on holding down the STORE) would wake it up again.. So, after i got sick of it (1996?) i put it on blocks, sometimes checking to see how mad it was as the years went by.. Obviously, now, in 2008, the machine is 22 years old, and really desireable, so i decided to try and make it sane.

    The Problems:

    Random freezes, lockups etc. Lights on panel go out, screen fills with "@@@@@@@@@" etc..

    Difficult to start the machine from cold.

    Voice 6 Fails / sounds Different to the other voices, or acts up on some patches. Confirm WAVE ERROR (usually 63) - during the CALIBRATION, hold down the COMPARE button and a WAVE ERROR appears..

    Note: If you remove the CEM chip for voice 6, and swap it with one of the others (easy to do on the 6 and 6r as the chips are in sockets), the fault IS THE SAME - this eliminates the hens-teeth CEM chip, and means something else in Voice 6 is iffey.

    SO, first off, need to rebuild that PSU, so take it out and make a note of what all the capacitors are (picture 1) and what the regulators are, (1 x -12v, 1 x +12 v, 2 x 5v and 1 x -5) - order them up from RS or pester your local fusepusher.
    I won't make a list here, because i know they used several different PSUs depending on where/when you were.. Probably.. Take a picture of the PSU before you start so you can check your work afterwards.. remember the Caps must go back in the way they were in the 1st place.. So, go ahead - Get those badboy Regs and Caps out of there and replaced with nice new ones. Remember the regulators have to be isolated from the plate they are bolted onto - so KEEP all the washers and plastic bits, you will need them.. Use solder wick/whatever to remove the parts, and clean up the excess solder, making sure you don't destroy the board like i did (picture 2) - but don't worry, it's bound to fall apart when you work on it - it is after all CRAP, so be prepared to make some jumps with the leads of the caps if need be (look closely at my mess..) Anyway, do it, and set aside all the bits you replaced to show your mates later (picture 3) and you are ready to put it back in the machine (picture 4) - CHECK THE CAPS ARE IN RIGHT!!! Stripes to - (minus) ok?

    Hook it up and Reboot it. Don't worry if it appears to be dead at first, it isnt! keep switching it on & off and holding STORE and whatnot etc. Eventually it will behave, especially if you undo the ribbon connectors inside, then firmly reconnect them..

    Do the Calibration a few times, is it happyier? Do you need to work on voice 6? you do? proceed then..

    Now you can work on the voice board. (Picture 5)
    Attached Files
    Last edited by playthatbeat; Thu 14-08-2008, 11:30 PM.
    jUst plAythAtbEAt

  • #2
    Parts Per voice: some 4.7uF 25v caps , some 10uF 16v caps , 1 x 14-way DIL socket, 2 x 16-way DIL socket, 2 x MC14051BCP (8 channel mux/demux chip), 1 x 74HC32N (quad 2 input "OR" gate)

    Get the voice board out - taking a picture of it first so you can etc. etc. and have a look around Voice 6 - see the Cap in the middle? the one that's in the same place on each voice? It must be changed, as should all the caps around voice 6 (when in rome..) You also want to do the caps up in the corner of the board near voice 6, and any others you don't like the look of.. It will be good practice for removing the 3 chips! You should remove the CEM chip and put it somewhere comfortable to be safe. And cool. Get those 3 ropey chips out, clean up and replace them with DIL sockets.. I chose DIL sockets for this as i am reliably informed the OR gate chip is notorious for going lame, so i expect to replace it again in another 22 years. er.. Also, in the pic below, you can see i didn't have any 16-way sockets, so i improvised with some other smaller & larger sockets i had.. OK, then insert your replacements into the snazzy sockets , and refit the CEM chip, check Your work against the piccy you took, and then you can put it back together and try and wake it up again!

    Again, this could take a few ON/OFF and ribboncable resits, but it will boot, and will fail the first calibration or 2 as before (hold button COMPARE during calibration), but, the VOICE 6 will be perfect 2 calibrates should result in no fails, and a perfect working non-mad matrix synth!

    I stuck in the factory patches,and had a little jam for you - apologies for the noise in the b/g i took NO care during the recording.. But, as you can hear, it's silvery

    I DID recalibrate it, using the proceedure in the servicemanual and a frequency counter.. i calibrated to ~3.25MHZ on each channel, as it was way down on what it should have been, this HAS made a difference..

    So, the culprit in all of this was a combination of crappy PSU and ropey chips.. But now i HAVE THE POWER!!!!!!

    That is all.
    Attached Files
    Last edited by playthatbeat; Thu 14-08-2008, 11:35 PM.
    jUst plAythAtbEAt


    • #3
      SO HOW DOES IT SOUND????????????
      Attached Files
      jUst plAythAtbEAt


      • #4
        Sounds pretty darn cool


        • #5
          Savage warpy electronic soundz

          It's sounds Very daft Punk @ the start, that is some machine man!, Does it record too? like play it whilst recording then upload it for the edit or do you just play live over your tune?
          ♪♫♪♫ NoT fOr ArMeR ♪♫♪♫


          • #6
            Burn It

            Burn it. Burn It NOW.

            AFAIK, u have a Matrix 12, so the other is very sub-standard... Give it a good burial.. The 6th VCO was the last in a line of staggered chips increased for polyphony, (hard ass ROM coding) so it'd probably be the 1st one to fail. Chris over in pure logic got stung the exact same way. Martix 12 is a faaaar superior machine, as u know yerself. The Matrix 1000 was just a regeneration of the most well known presets. Gah!


            • #7
              the speakers at work weren't able for it but some interesting sounds


              • #8
                Mmm.. the matrix 12 is very similer alright, but a different sounding beast, and a tad laggy to be honest.. The m6 is alot snappier, and is alot easier to make crazy noises on.. The m12 doesn't have all that menu - adjust nonsense, there are knobs to click with and buttons to press and so on, so you think it's gonna be easier to programme- but it ain't.. i must compare the voice structure on the 12 and 6 - i think the 12 may be a bit more complex, but is basicly the same beast..

                Nah, no junking of the m6 - it's a wonderfull machine, and now with it's new-found sanity, is actually worth the time taken to get it cooking! I will love and care for it untill the next time it looses it's marbles..

                armer - no, it's purely a sound-making device.. made in the days when keyboards needed to make a decent piano sound1! lol!! it' needs either a person to play it, or to be played thru MIDI to get it to do anything.. The thing that made the MATRIX series stand out was it ability to use pretty much any value or event to influence pretty much any other value or event in side the machine.. it also had that cyborg thing going on - 1/2 computer, 1/2 analogue moise, 1/2 pig, so it could do some very precise chaos!!!!!

                Anecdote: the matrix synths were capable of infinate evolving sounds (relatively speaking) - some modulators could be made do their thing over HOURS.. a single mash of the keyboard could be made trigger a series of events that could take a day to complete! mmmm... pointless
                jUst plAythAtbEAt


                • #9
                  A week+ on now, and the M6 has been a bit mad again Not as bad as it used to be, but still, a little strange.. So i re-calibrated the HFOs as per the service manual's instructions, and decided the original ribbon cable was the culprit.. a Clue: when i leaned on the connector into the logic board, the machine froze! So after checking the tits out of the board, and doing a few cap replacements to cheer me up, i replaced the ribbon cable with an old 40-strand IDE cable, with plugs for 2 drives.. It's awkward, you cannot open the lid anymore fully - since the lead is spaced differently to the one that comes with the M6, but it is now solid. I mean really solid. Not, like, ALOT BETTER THEN IT USED TO BE solid, but really 12-hours of use with no pops and messing solid.

                  The old ribbon cable was just a bit loose. Really didn't satisfy when you plugged it in.. The replacement IDE cable DOES. it's wonderfull. But, you need an oldschool one - not one with a pinhole blocked, like an 80-strand or a cool tuners cable.. An old one.. all pinholes open..

                  Someting strange though.. The patch 99 preset - the SMPLETHIS patch now sounds totally different! i don't understand why, but it's changed from the way it sounded just after i did the initial fix! Now it has a wooden tone, and behaves very strangely if you play it right! A few patches sound kinda different now actually.. Amazing what detuning the HFOs can do for the whole behaviour of things.. This time, i didn't rely so much on the freq counter, i just got one of them where it should be, then tuned in the other 2 by ear! It's damn confusing, but you can hear which one you are adjusting, and hear it "beating" with the others as it drones during the Routine for tuning the HFOs.. You can get these things SO close to each other! it's amazing how much resolution is in there! Just, if you want to play with this, get the right tool to adjust the coils, coils are fragile and if you bork a coil, you certainly WILL have an interesting sounding M6. I predict when i use it with other instruments it will be a tad off concert pitch, but who cares, i don't have 1 instrument that stays at 0 pitch as it is.. they are all a bit different from each other.. GO GO NOT-MAD M6!
                  jUst plAythAtbEAt


                  • #10
                    Here is a rip of the original Matrix 6 audio cassette from oberheim, dated 3/6/1986 entitled: FACTORY STOCK PATCHES/VOLUME2 in .wav form..

                    You can use this to restore patches to Your machine when the battery dies and you couldn't be arsed looking for a sysex dump to get it normal again..

                    Sometimes the machine corrupts it's own face for other reasons - some patches behave strangely, and You think maybe the hardware is about to fail bigtime - this can maybe be just plain old brainrot - try backing up Your patches first, then get these in and see how it sounds..
                    Attached Files
                    Last edited by playthatbeat; Wed 20-10-2010, 2:28 PM.
                    jUst plAythAtbEAt


                    • #11
                      New Firmware..

                      A smart cookie, Bob Grieb, has been doing some poking about with the firmware of the M6/M6r, to improve it's habitual clogging, read about it and get a copy here: Have not burned his code to an eprom yet, but i will next time i get a hankering for some m6 action.

                      He has also released modded firmware for the matrix 1000 here:

                      and has an interesting observation for those of You with MAD VOICE syndrome:

                      Great stuff
                      jUst plAythAtbEAt


                      • #12
                        My m6 went batty - lost a voice, so i swapped the voice chips about to see if it was the CEM, and LO! it's happy again..

                        Uploaded the factory patches, and although they gave an ERR 5 or ERR 2, they did load 100% :/

                        ALSO: installed that rom (above post) so i ripped my ROM and attached it here - it's for a 27C256 eeprom, and is marked as "M6R 2.13" - so appears to be the firmware for the RACK M6..
                        Attached Files
                        jUst plAythAtbEAt


                        • #13
                          Service manual, in case You cannot find it, or more to the point, in case I cannot find it
                          Attached Files
                          jUst plAythAtbEAt


                          • #14
                            Something just had me going round in circles for a while.. A clicking voice, or a trembling voice, or a digitally unstable voice-fault that MOVES depending on where You are playing the keyboard - so, it's not the voice chip itself, it's something more annoying..

                            Anyway, it was the ribbon connector that chains the boards and the control board - anything up with that, and expect a fault that seems to jump from voice chip to voice chip, and cannot be attributed to any single voice.

                            Same lead as an UNBLOCKED IDE lead - ie: with no key pin that is blocked..

                            Hard to find these days, but it's bound to be behind any mad digital/control problems - reseat it, be gentle..

                            A clue to this problem will be if You are holding the garbled voice ON by pressing a key, and you open and close the lid while doing this, and the fault changes as you move the lid - then it's the ribbon cable, likely with a GND problem, but a severe disruption that will get worse or better as You move the lid..
                            Last edited by playthatbeat; Sat 11-06-2016, 2:31 PM.
                            jUst plAythAtbEAt


                            • #15
                              SYSEx All Patch Dump before PS Rebuild...

                              Greetings and thanks so much for this info.
                              I am about to rebuild my power supply for my Matrix 6R, which i purchased NEW in 1986!
                              I'm having that gobbledygook on the display, but thankfully all voices are working fine...

                              My question sounds terribly "newbie", and I'm not really a total goofball, I promise, but I'm a little unclear on something:

                              I am trying to dump all my patches via MIDI SYSEX before I begin these repairs.
                              I have the M6R hooked up to Protools, and I record a block of data and can see the SYSEX data chunk in PT.
                              Now I want to verify that that data is good, so I alter a patch name and save it, then wish to reload all the patch data from the SYSEX file in Protools, (to see the name restored as a sign that the data was replaced). I hit play in PT and see MIDI activity heading to the M6R, but it doesn't look like anything happened, i.e. the altered patch name did not revert back to the original name.

                              I feel as though I'm missing something stupid, but how do I set up the M6R to load all the patch data from the SYSEX bulk dump? The manual only mentions how to SEND this data, not how to load back from such a data dump.

                              Please advise, and again, apologies for the stupid question.