AES is differential, 2-signals and ground. S/PDIF coax is single-ended, 1 signal and 1 ground return.
If you want to change AES to S/PDIF, you can do this easily with a voltage divider on the + signal (pin2) to ground. The values of the 2 resistors must be correct and precise, usually .1% tolerance. The values depend on the driver impedance.
Steve N.
Empirical Audio