Many thanks to everyone in the Super JX community that make these projects worthwhile. Special thanks to Keith Meiere, Fred Vecoven, Jonathan Williams & Alex Bhinder for providing the instruments, support and enthusiasm to drive these projects.
JD 800 Keyboard Flexible Circuit
A new flexible circuit board for the Roland JD-800 keybed. Time to fix your JD 800 keyboard!
Modern materials and manufacturing techniques. Employs gold plated contacts, Polyimide base layer and new transition PCB.
Engineering data complete, quotations for tooling being sought. To aid in the high costs of tooling a large flexible PCB, Jonathan Williams and PCBWay have sponsored this project.
A guide showing the technicalities of making Flexi circuits with free tools is here
Watch this space!
First samples have arrived. Mechanically fits ok. Manufacturing process shrinks material by 1mm per meter. Built in tolerance avoids issues, first samples need end point fixing holes trimming.
They do look fantastic with gold plated contacts.
Next steps: Design test equipment to confirm all contacts, connections and vias. Obtain spare metalwork for fixturing and checking purposes. Write a fitting guide whilst rebuilding the first keybed.
JX-8P OLED Display
A spin off from the JX-8P Vecoven Flash project and JX-10 replacement display, it enhances the display significantly when used in conjunction with Vecoven upgrades. Compatibility is provided for other firmware and even other instruments that use the same NEC controller in one line mode.
Testing completed, instructions written and first build of 6 has been completed, orders can be shipped.
February 2021 – Manual Ready & Testing Almost Complete
A huge amount of progress made coding special screens with a small modification to the Vecoven SuperJX Flash Firmware to add extra functionality.
Great care has been made to ensure that the replacement emulates the old display with nearly all supported commands and features with a 16 x 1 character emulation.
Only marketing data now needs to be completed.
January 2021 – Software Completed
Design of new layouts for extensions when using Vecoven SuperJX Flash module.
Next steps are to write an installation manual, update website and show some pictures.
Almost ready for release!
December 2020 – progress on software
- JX8P 6303 & pic18f display code running under an emulator and virtual machine, with OLED and VFD hardware emulated in Java
- Build variants for JX8p and JX10 on display code.
- Prototype installed in an instrument, basic Roland mode works perfectly.
- New PCB that has fitment options for all SuperJX and 8P versions has been ordered.
- Bootloader for reflashing when using with new Vecoven firmware.
November 2020 – progress on software
- JX8P display protocol added to SuperJX display code base allowing different build versions.
- JX8P version has access to all SuperJX display software features including OLED/VFD compatibility with it’s bitmap fonts, layouts and character displays.
- Plan is to extend the display arrangement when using Vecoven SuperJX Flash.
Picture above shows software being tested with VFD in it’s character mode. All other modes were tested including graphic.
It is a shame that in the JX8P, replacement VFD will not fit inside and power supply is too weak. It could be addressed with a new display board or some advanced mechanical modification.
October 2020 – progress on test board
- Software protocol handler written
- Further display chip commands discovered and analysed: All Roland VFD displays understood
September 2020 – significant progress made:
- Test software written that exercises every function and performance of the original Roland design
- Specification written that describes all the technical details including timing & commands
- Test set updated to test production displays
August 2020 – Explore Possibilities & Displays
The picture above is from some concept work done by Guy Wilkinson and Jonathan Williams. It just shows the “Splash screen” for JX10 for basic testing of what is possible with the window, apologies to Fred for cutting off his name, see second picture!
The mechanical design is especially difficult due to very precise tolerance and limited space behind the bezel, it needs to look straight whilst being easy to fit.
D50, DX7IIFD, DX5, M1 OLED Displays
This is the same display as used in the JX10 and MKS70 OLED kits.
Instruments require de-soldering and soldering plus front panel disassembly. Korg M1 kit available that doesn’t require soldering.
Completed for D50, DX7IIFD, DX5, M1, MKS-80 and available here.
Power Supply Overvoltage Protection Measures
A number of reports are coming in where power IC M5230L reference circuit fails. When it does, it puts 44v across the analogue circuits and 7v on the logic causing damage.
A couple of component additions to existing PSU are being worked out using additional components to try and limit damage.
MKS 70 Gate Array Replacement
A spin off project from above when debugging a faulty MKS 70 at Plasma Music.
A PCB has been designed that replaces obsolete components on the assigner.
It also means that reliability of the MKS 70 is better assured and could be a donor instrument to fix a JX 10.
To help debug faults before changing the IC, some gate array test software is being written.
An EPROM can be installed that runs tests on the gate array functions and reports where faults exist either through bad connection, external RAM or IC itself.
August: Sample PCBs ordered ready made from PCBway!
September: PCB samples ready & donor MKS70 arrived for testing
October: Hardware tested & proven
Xvive Audio Chorus Chip Trial
Spotting the tell tale signs of noise and periodic interference of old devices followed by a test of the Xvive Audio chip to replace the Mitsubishi BBD IC MN3009.
Article will show replacement of the devices in a SuperJX.
Completed and can be seen here.
Copyright © 2020 Super Synth Projects, Guy Wilkinson