AES3 (AES/EBU)

The Audio Engineering Society and the European Broadcasting Union published it in 1985, hence the nickname AES/EBU. The signal runs over 110-ohm twisted pair with XLR connectors — the same plug the microphones use — and reaches past a hundred metres. Each frame carries two channels at up to 24 bits per sample plus status bits, and the clock is embedded in the stream through biphase mark coding.

The consumer variant, S/PDIF, is essentially the same frame format with cheaper cables and lower voltage. Because the receiver recovers the clock from the signal, AES3 is sensitive to jitter, so larger studios lock everything to a separate word clock. Networked audio such as Dante has taken over newer installations, but the XLR socket labelled "AES" is still there.