Enhanced Memory ME-1 for Kawai K5000
Kawai K5000W
Update 2011
After some years of this project, some of the main components on my ME-1 replica board are obsolete or very hard to buy. I am working on a new series with some other components.
The RAM-controller MAX691A
This part is still in production, however the price raised to inacceptable 4,90 Euro each (mid 2011). The MAX691A now comes from Poland.
The RAM-device
The 256k x 16 Bit RAM was made by Brilliance Semiconductor (BSI). Now, BSI is in trouble with nearly all their European distributors, and I have to find replacement. There is a cross reference to a Cypress RAM, which is identical in case and pinout, and similar in other parameters, like access time, voltage, current, power down current and retention voltage.
Cypress Semiconductor
The AMP-connector
This one is still available at RS or Farnell. I got it from TTI this time for a quite low price.
AMP FH series connector
The battery holder
The Sony battery holder is obsolete; that is what I was told from Jauch. I preferred to find a replacement that is easy to use and on the other hand has the same spacing. The Sony type needs two plated through slots in the PCB..
Sony battery holder
MPD battery holder
I decided to use the BS-7 type by Memory Protection Devices (MPD). It has also a 20 mm spacing, but normal round pins. So there are only minor changes needed on the PCB.
The PCB
For this reason, the PCB had to be changed. There were also some improvements on the board. Here is the PCB with round battery holder pads, ready by now.
2011 PCB layout
I will have to order some prototype PCB now in order to test all the new components, before ordering larger batch of PCBs.
Update 16.2.2012
I have ordered a sample PCB. It contains the new ME-1, and also my latest project. A flash SIMM memory board with 2MB flash ROM. This will be used for EMU E4-Classic series samplers to perform a OS upgrade from V3.xx to V4.xx. Most EMU classic samplers actually have 1MB flash ROM, however OS V4.xx needs 2MB.
Both prototypes were combined on a single PCB to reduce the costs.
Sample PCB 2012
Update 8.3.2012
The sample PCB is now ready. The two ME-1 boards are already missing. The EMU E4 Flash ROM is still to be seen.
ME-1 sample PCB
This is the ready assembled ME-1 with the new components. It has already been tested successfully. Both modules however showed a slightly higher consumption of battery current. The Cypress RAM takes 1.2 rsp. 2.5 µA, while the BSI RAM took less then 1 µA.
According to its specification, the Cypress RAM may have a standby current of 1 to 7 µA, which will result in a battery life of 3.4 years in worst case, and 8 years in an average case. This is a compromise we will accept..
ME-1 2012 front and back
I stored a random data pattern on one of the modules with battery inserted. After one week without voltage supply the data were still kept with no error.
Update 16.3.2012
After panelizing the boards, a production panel was ordered. Delivery time will be 7 working days.
Update 19.4.2012
The ME-1 PCBs are now assembled.
ME-1 assembled boards
20 years old Siemens MS-90 pick and place machine used for assembly. Still reliable and precise.
Siemens MS-90 pick and place machine
Hot air SMD reflow soldering machine
The single board with the new Cypress Semiconductor RAM chip. Some short circuits at the connector and the chip have to be removed manually.
ME-1 single board
Lead free SMD rework tools
