Making your own MIDI Cables

NOTE: If you plan to hook up your Sound Cards's Game Port to MIDI cables, so that you can use external MIDI devices, please see: Using your PC's built in MIDI Adapter. Its not simply just a matter of soldering up connectors to wires.

Why make your own MIDI Cables?

Try to find cables this length. I did locate some via a mail-order place, but they cost as much as the cables that were 12 feet long. I didn't need these to be built all that tough, since they would permanently be installed in an enclosed cabinet. So. I had 2 options - coil up large lengths of expensive MIDI cable and toss it into the back of my rack-mount boxes, or make some that were much shorter and more cost effective.

What's in a MIDI cable?

Looking from the inside of a male 5 pin DIN connector - this is were you will be looking when you solder up the wires

Out of the 5 connections on the DIN connector used in your MIDI cable, only 3 are wired to anything (altho some MIDI cables manufacturers do wire all 5). The DIN connectors are available via mail order or at the local Radio Shack (buy them mail order if you need many of them - your average Radio Shack store will probably only keep 4 on stock at any one time). You need 2 5 pin Male DIN connectors per cable. The cable needs to have a single shield covering (usually copper braiding or wrapped) and you need 2 conductors. This is just like the wire you would use to make up a low impedance XLR cable with. You can buy a 25 or 50 foot (8 to 16 meter) spool of the 2 conductor shielded microphone wire from Radio Shack, or mail order it when you are getting your DIN connectors. The wiring is quite simple. Pins 1 and 3 are unused (these are the outer most 2). Pin 2 is the shield (this is the middle pin) and pins 4 and 5 are the signals. You always connect pin 4 on one connector to pin 4 on the other. You always connect pin 5 on one connector to pin 5 on the other.

If in doubt, get your trusty Multi-meter out and check to see which pins connect thru a known good cable.

Making the connections

With your fingers, lightly twist the ends of the wires so that they all come together in as small a space a possible, and they come straight out of the wire. Also lightly twist the shield in the same way. Tin the ends of each wire with Solder. Use only the least amount of solder as is necessary.

The next step is to disassemble the 5 pin DIN connectors. These will come apart in 4 pieces - they will be:

• The slip on cover (plastic, unless you bought one with metal covers).
• The 5 pin DIN pin connector plate (this is where you solder the wires).
• 1/2 of the metal guide (it will be keyed so that the 5 pin DIN pin connector plate only fits into it one way).
• The other 1/2 of the metal guide.

Once these are taken apart, slide the 'slip on covers' onto the wire such that the large openings are facing the ends of the wire (these hold the connector together - don't forget to put these on before assembling the rest of the cable).

Pick up the 5 pin DIN pin connector plate and carefully slide the lightly tinned shield wire into pin 2 (the very middle pin along the outside edge). Use your soldering iron to warm up the joint on pin 2 and lightly touch the solder to the pin. Solder should flow. Use only as much solder as necessary.

Do the same for the other end of the wire. Make sure that the slide on overs are still in place and are still facing the right direction (large open end towards the end of the wire).

Since you may have wire with different colors than I have, I can't tell you which color wire to solder, however, I always wire the darker color wire to pin 5 and the lighter color wire to pin 4 - this helps me to remember which one goes where when repairing cables later. You may want to do the same. After making up over 100 MIDI cables - its become second nature to me. I'll describe the rest of the assembly using this system.

Take the lighter colored wire and insert it into pin 4 (see picture above) and solder it. Take the darker colored wire and insert it into pin 5 and solder it. Switch to the other end of the wire and do the exact same procedure for that end. When you are done, all 3 connections should be wired the same for each end of the connector. I like to cut very short lengths of electrical tape (1/2 inch by 1/4 inch - 12 mm by 6 mm) and wrap around each solder joint to prevent a short circuit from occurring. There should be no wires connected to the outside pins (1 and 3) on the 5 pin DIN Connector.

Now that the connector is attached to the wires and you are certain there are no short circuits, assemble the 2 metal halves around the 5 pin DIN pin connector plate. It only fits one way - one of the metal pieces should be keyed. One of the metal parts should have a place that allows you to crimp the metal part to the outside of the plastic insulation covering on the cable - use pliers and lightly compress this so it holds the wire, but don't press so hard that it damages the inside of the wire. Slide the plastic cover down over top of the 2 metal pieces (while you are holding them and supporting the 5 pin DIN pin connector plate between them) - this plastic cover will usually be keyed and will fit on only one way. It should lock onto the metal guides and once this is in place, you have finished that side of the cable. Do the same for the remaining side of the cable.

The parts of the connector Assembled

Each assembled end should be connected in this fashion. This should help to visualize the parts inside of the assembled connector and how things align.

Once you have assembled all the parts, use your Multi-meter and verify the pin connections. You are done with the cable and ready to make the next one.

Test the finished cable using a MIDI keyboard and Synth module (or any other MIDI gear you have available to test it with).

Ready for more!

There is quite a market for short MIDI cables - you may run into people who need them. If you enjoy making up cables - there is definitely a business opportunity here, provided you can keep your costs down. I've wired up other peoples MIDI racks and made appropriate cables as a part of the service.

Questions? Comments? .

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