Well, Yes AND No...
Yes you can use a STANDARD (40pin/40wire) 16-bit IDE cable in place of the AD_EXT connector. The AD_EXT connector is also 40 pins across (though only 35 actually are used). Just be sure you align pin 1 and pin 2 on both ends of the cable and face them the same way (or with pin 39 and 40). If you plan to make it a permanant replacement, I suggest 'blocking' the unused pins either with plastic pin plugs (if you got them) or just do what I did and use a glue gun.
No you can NOT use an UltraATA (40pin/80wire) IDE cable. The pins do not all connect straight across (pins 34, 28 are disconnected on the Blue(System) and Grey(Slave) connectors, respectively). Many of the wires are also briged together into a broad ground sheild to protect the signal integrity.
XFi users, your cable mapping is the same and the pin count is still 35, and any other simmaler or newer card might work too (so long as the pin count is no more than 40 and there are no blocks or twists).
Hope this helps.
Gabriel
www.paradisim.net
PS: Details about the differences between the two can be found here..
http://pinouts.ru/Multimedia/sb_audigy2_ad_ext.shtml
http://www.technick.net/public/code/...bdts_ata66_100
http://www.technick.net/public/code/...conhdd_ide_int