Connecting PS4 to old surround sound system

I had my ps3 connected to my Sony- DAV-DZ260 DVD home theatre system. This was so I could have surround sound for games and blu-ray. I did this with an optical cable connected from the ps3 to the DVD player, and then in the audio settings on the ps3 I selected the optical output (leaving the HDMI for visuals). Then I selected the function on the DVD player as 'TV', and all audio sound from the ps3 played through the DAV-DZ260 speakers- which was great.

I have now upgraded to a ps4 and assumed I could use the same setup. However when I do the same thing I do not get any ps4 sound from the speakers. Can anyone tell me what i'm doing wrong?

Thanks

Scott