You can re-use your original plug by
splicing it by its old wires onto the new cable. The old wires probably have some sort of enamel coating, and you'll need to carefully burn that off with a lighter before soldering. Otherwise it's better to just get a new plug.
When recabling, it helps to have a reference of what the original wiring was like. So when you open up your AD700s, take a picture of the insides first before soldering anything. (And if the picture turns out well, post it here so others in your position may benefit in the future.)
The wiring probably follows these colours:
Left - white
Right - red
Ground - blue
And this matches the TRS plug like so:
Get a digital multimeter if you can, and use it to trace the continuity of the wires to the plug so you know everything is going to the right place.
If you're looking for a cheap and easy replacement cable, there's some from Digikey:
- http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=839-1040-ND
- http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=839-1034-ND
And Mouser:
-
http://ca.mouser.com:80/ProductDetail/Kobiconn/172-7438-E/?qs=sG...
-
http://ca.mouser.com:80/ProductDetail/Kobiconn/172-7433-E/?qs=sG...
Otherwise you can get
Mogami 2893 (preferred if you don't have a multimeter), or
Canare L4E5C, and solder on your own
stereo plug. Those two cables I just mentioned have 4 wires each. You combine two wires together for the ground channel. There will also be a shield around the wires. Combine that with the ground channel at the plug only.
Or if you're feeling very adventurous, you can buy a single-wire spool, and braid it into a 3-wire cable yourself.