Yamaha offer a range of YGDAI cards which are compatible with the 03D https://uk.yamaha.com/en/products/pr...rds/index.html

The link is for all the analogue cards available, but there are multiple digital formats available as well.

You have the AES/EBU card which can output 4 x 2 channel AES lines (there are two different cards. The one with the 'S' suffix offers up to 96kHz sample rate. The other card only goes to 48kHz) via your D Sub cable.

If you go for the analogue o/p card with the D Sub output, there are various different wiring standards for analogue and digital, and Yamaha and other manufacturers (Tascam/T-DIF being the other main standard)