Developments

Many thanks to Jonathan Williams for providing the instruments, support and enthusiasm to drive these projects. OLED display manufacturers generally only supply in large volume. These two derivatives will allow increased purchasing volumes for the OLED display thus maintaining supply of the original JX10 and MKS70 OLED kits.

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.

Completed for D50, DX7IIFD, DX5 and available here.

Korg M1 requires an adapter PCB that has been designed and is currently on order. A kit will be made available.

JX-8P OLED Display

A spin off from the JX-8P Vecoven Flash project and JX-10 replacement display, it is intended to work in conjunction with Vecoven upgrades for full effect. Compatibility will be provided for other firmware in one line mode.

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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!

P1120959

Development is underway, but note that it is a huge amount of effort producing a product like this with construction/fitting guides, software and custom display arrangements. 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.

September – 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

October – progress on test board

  • Software protocol handler written
  • Further display chip commands discovered and analysed: All Roland VFD displays understood

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November – 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.

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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.

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.

610-Completed

MKS 70 Gate Array Replacement

A spin off project from above when debugging a faulty MKS 70 at Plasma Music.

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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.

Layout18-Jul20

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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.

mn3009

Completed and can be seen here.

Copyright © 2020 Super Synth Projects, Guy Wilkinson