Auster 隨手亂彈

(1) AES/EBU output to S/PDIF input

Electrical format:

To get the most reliable interface, the noise immunity of the electrical interface should be maximized.
Drive level and impedance is higher with the AES/EBU interface, so the best solution is to use a resistor network as shown below to match both parameters.

Data format:

On some equipment, an S/PDIF input processes 16 bits, on other 20 or 24 bits. You should find out how many databits is being processed, and set the AES/EBU output dither accordingly. - All TC Electronic units process all 24 bits.

Most consumer units with S/PDIF inputs may reject AES/EBU status bits.

AES/EBU output to S/PDIF input Cable - with impedance and level matching

(2) S/PDIF output to AES/EBU input.

Unless your S/PDIF transmitter uses the 4 aux data bits for something else than audio (which is very unusual today), the problem from going S/PDIF to AES/EBU is typically electrical.
The best solution is to use an active balanced digital line driver close to the S/PDIF output, and 110 ohm cable onwards, but for short term setups, you may get by more easily: A 75 ohm cable with a RCA phono type of connector in one end directly into a XLR male plug wired like shown on the drawing below..

Because of the low level and unbalanced output signal, the cable should be kept short (less than around 5 meter).

S/PDIF output to AES/EBU input cable, Neither with impedance nor level matching