JX PWM kit

The JX10/MKS70 have an analog PWM kit available for quite some time now and it sounds fantastic. However, installing the kit requires a lot of time because of all the wiring required to connect the daughter boards to the sound boards. A new solution has been developed where the counter chips (on each sound board or on the main board for the JX8P) are replaced by a FPGA. The FPGA produces the exact same square waves as the counters (so no difference at all!) but they can also directly generate PWM waveforms. As a side benefit, the FPGA board uses less power than the old counter chips, specially on the JX8P which used NMOS technology chips. On the JX8P, the power supply bridge rectifier will run about 30C cooler!


Now a tradition, Guy Wilkinson has written an excellent page on this upgrade : please read it here.

The kit comes complete, you just need to desolder the 4 counter chips and the old 8031 CPU. Note that some JX8P (the latest ones) had their eprom B soldered, so you will need to desolder this as well. The kit contains a high quality socket for the new CPU, the CPU itself, the FPGA board (with all pins already fitted) and the new EPROM(s).

Note that the kit requires firmware 4.x on the JX10/MKS70 and firmware 6.x on the JX8P. On the JX8P, a flash module is required to run the firmware. On the MKS70/JX10, it is optional (an eprom with 4.x is included in the kit if you have no flash module).

The new kits are priced as follow: 80€ for the JX8P, 150€ for the JX10/MKS70. Shipping is extra. Please email me for ordering.

Interesting links:

The install manual is in the download section.

Some pictures of the first kit, fitted in my MKS70: