The point on our Activities

Nearly 3 years ago, I started to develop the Matrix Ctrlr.

I would like to thank a lot the early customers of this device for their confidence. This was a very challenging project ! Involved in the Do-It-Yourself community since 10 years by assembling and modifying others designers products, this time, I was designing my own product, mostly from scratch, using open sources solutions (software, codes, platforms).

Producing a circuit and even a complete kit for a device isn’t that easy. You have to deal with technical, dealers, budget, sales, distribution and support sides. But passionated peoples have given me the strength to do it !

Notice that Alpes Machines is an activity run by a single man besides a full time job 35hr/week (sound engineer for Radio France) with modulated working hours (weekend, holidays) ! So it is a bit complicated to combine a regular work, a passion, a self enterprise activity and, if possible, some personal life.


At the beginning of the year, the north american company Xvive resurrected the BBD MN3009 & MN3007. This chipset is in every best chorus ever produced : the Roland choruses !  It was the opportunity to run new products : the JuCe and the One-O-Six, both analogue stereo chorus based on BBD technology.

I’ve decided to choose these chipsets for their low noise in comparison to the modern BBD distributed by Cool Audio. I had already modified circuit boards produced by Roland & Boss, and it was time to design my owns.

Documentation and website are going slowly on this new products but I must confess this is not my cup of tea, particularly after spending hours in circuit design on Kicad and IRL prototypes tests.


I’ve started to distribute the first board of the One-O-Six as a kit last week and I would like to thank the early customers who will be the beta testers in some way, not of the circuit as it is perfectly working, but as builders !

We hope this will growth the interest in the One-O-Six Chorus so I could design an industrial board with SMD components and thus open this device to more musicians and engineers at an interesting price to produce subtile sound and music 🙂

I’ve been reflecting to the best method for this, and a participatory financing could be the solution. What do you think about ? You can express your opinion in the comments.



PS: notice the forum is back ! it will be more secured against spam this time

Julien V.

Upgrading Matrix 1000 early board

We have recently discovered that the Japanese Matrix 1000 boards were early revision and had to be modified to be compatible with firmware 1.11 and 1.20

Most of the time they have an EPROM 1.03

If you notice that patches don’t sounds the same after an upgrade to 1.20 and a calibration, then you will have to do that modification to the board.


More technical details are explained by Tauntek :

Early Matrix 1000 issue with any new firmware

    Someone whose M1K shipped with V1.03 firmware was having problems trying to use V1.11 or later firmware.  It turns out that the circuit was modified very slightly at some point and this change is required to run any firmware released after that.  If you look at the above-mentioned scans of the Oberheim schematics that John Leimseider provided, you can see mention of several ECOs.    The one that seems to be critical for running the newer firmware is ECO 1207, which connected the PULSE output of comparator U4 to the CTS input of 68B50 U809.  Before this ECO, pin 24 was tied to gnd, so that connection was removed.  The M1K calibration firmware was changed to read the PULSE state using the ACIA chip’s spare input, and will not run properly without this connection.  ECO1207 also connected PULSE to the MUTE signal using a 1N4148 diode.   This would tie the (open-collector) comparator output low during normal operation, since it’s only needed for calibration.  This change is not required to run the newer firmware, but is probably worth adding anyway.


We then compared with our good old Matrix 1000 bought in France in 2009 – hence certainly issued from the french market – and guess what ? there is a wire between two chipsets as Tauntek said ! So it is time to upgrade that japanese board to the latest revision.

You will have to cut a trace and solder a wire between two pins on the bottom of the board. You could also desolder the chipset and do the same thing as on the french board but it is tricky if you don’t have a desoldering station … As we will remove the main board and the heatsink to flip the board, we will also upgrade the battery with a battery holder (CR2032).

To modify early board, cut the ground trace underneath (bottom side of PCB) that goes to U809 pin24 and solder a wire between U809 pin 24 and U808 pin14 :

Moreover there is an additional signal diode 1N4148 between a via (cathode side of the diode) and pin 7 of U4 Opamp :

Once it is done you can reseat 3 screws and test that your synth is working as expected by launching a calibration procedure (Fonction TST / 7 / enter / 0 / enter – see the user manual if necessary) and playing some notes on different patches. Notice that patches 000 to 199 are mute as you’ve removed the battery (reload your Banks via SysEx).

If it is positive, reseat all the screws and the nuts and close the rack unit to enjoy your upgraded and modified Oberheim Matrix 1000 !