Am I stupid and can't see it?

I've just bought a Sagem DTR, plugged it all in, in the right places I hope, got it all tuned in and running but there is one thing missing. THE SOUND! Could anyone out there tell me what I might have done wrong please? There aren't any audio leads that came with it. Do I need them as I haven't in the past? I bet it's something really simple but I can't see it and it's not listed in the troubleshooting guide either.