Syntech/Chroma Cult Installation
Installing the Converter in the Chroma
Here is one method of installing the MIDI converter PC board inside of your Chroma. This method probably requires the least amount of effort and I'm sure some of you out there can come up with some improvements to it.
- Remove the Chroma's cover and install two panel mount DIN jacks on the back. You will have to drill two 5/8" holes or use a 5/8" greenlee punch. I put my jacks 2 3/4" to the left of the big square cutout, one jack over the other. This spot leaves plenty of room to run the wires.
- Get a short MIDI cable and cut it in half. Strip and tin the leads and solder the ends to the two jacks you mounted on the back. For the input you only use pins 4 and 5. For the output jack you need to attach the shield to pin 2 as well. Make sure the pin numbers correspond, your are essentially making an extension to the jacks that are now on the back of the Chroma.
- Mount the converter PC board to the wooden post dividing the voice boards. Orient the converter circuit board so that the dins point upward with the components facing towards you. Use standoffs and wood screws to attach the PC board through its holes on the DIN jack side of the board. The wood is hard so you will have to drill holes for the screws. Also mount the PC board as low as possible so that when you plug in the MIDI cable plugs they won't hit the underside of the Chroma cover when you put it back on.
- Remove the small plate on the back panel of the Chroma and run the ribbon cable and the "D" connector from the converter out the hole. You can now connect the plug to the Chroma's computer interface whenever you want MIDI and disconnect it if you have to use the Apple interface. Be sure to unplug it when it goes in the case. If you prefer to connect directly inside the Chroma, get an IDC type connector like the one which connects the Chroma's computer interface into the Chroma's I/O board. Follow the cable from the computer interface jack on the back of the Chroma to where it plugs into the circuitry then unplug it. Cut the "D" connector off of the Converter's cable. IMPORTANT: You must now split the ribbon cable between conductors 12 and 13. The ribbon cable is 25 conductor and the IDC connector is 26 conductor. You must skip a pin in the middle, therefor the reason for splitting the cable. Make sure the ribbon cable's #1 (red wire) corresponds to the #1 on the Chroma's I/O board (to your right as you view the I/O board). This method obviously disables the Chroma's computer interface jack.
- Plug your newly installed DIN jack extensions into the converter PC board. The one closest to the edge of the board is MIDI in.
- Try to run the cables as neatly as possible so that you can easily put the cover back on the Chroma.