Special thanks to HL Forum member ElSmurf of Belgium for providing a detailed description of his excellent UMR2 MIDI retrofit module installation inside a Yamaha CS01. His words and photos follow.
I just finished work on my CS-01, so I thought I’d share the process with you.
My plan was to get the UMR-2 inside of the Yamaha without altering its functioning, so I could still be able to play it as is, with batteries and through the crappy speaker. This is way too much fun to do away with! So when I opened up the synth for the first time, I decided rather quickly that this would be the only place inside the enclosure that had enough real estate :
This presented two obvious problems though – one corner would have to be cut, and I would have to drill a hole to let the LED housing pass through. Cutting the corner was fairly straightforward but drilling the hole for the LED proved to be more challenging. On the larger version you can see how close the hole gets to one of the UMR’s LED leads.
I then attached 3 small bolts with nuts, and super-glued these to the case of the synth.
They kept the UMR in its place but also provided some elevation so the board sat ontop of the modulation destination slot.
Here you can see the LED hole alligned with the hole in the UMR. At this point I thought I didn’t actually need the contacts for the program switch, since I didn’t read the manual the whole way through. This obviously made things a little challening when it was time to do the setup!
Once the superglue was dry I could unscrew the nuts and remove the UMR to solder the cables.
I embedded the resistor and diode in the cable so it wouldn’t take up too much space.
Then came the scary part : drilling the hole for the MIDI socket !
First a 2mm metal drill, followed by a 10mm wood drill, and then a 10mm metal drill.
Then the big guns…
Getting that huge 16mm drill to tear up the plastic just didn’t feel right so I felt it was my duty to take some photos to compare the drill sizes…
I think you need a steady hand to drill in 30-year old plastic, especially considering how close you’re drilling to the edges. But everything worked out just fine.
Next up was soldering the other sides of the cables to the synth.
I have little experience with soldering on PCB, I mostly make only cables, so I was happy I had no shorts or burned through anything! After bending the cables everything kind of fit the way it fit before I put in the UMR.
A little interlude – my screw storage system :
Then came the hard part of doing the setup procedure. I had to put the synth on 2 small boxes so I could access the keyboard from below and access the UMR to short out the program switch. Which like I said proved to be tricky since the big contacts where gone!
Luckily everything worked on the first try, so after doing the setup and teaching it the matrix, all I had to do was cut the black cloth that keeps dust out to compensate for the UMR, and put everything back together. This is what it looks like now :
It took about 10 hours from start to finish, half of that time went in to cleaning – I dismantled the keyboard and cleaned every key separately. Now all I have to do is find my 2 missing slider caps – check the EG!