does true dolbydig output through optical???.

[zacoope]

Hello all..ive just brought a bdp-s370.my 1st dvd was gonna be transformers..my tv is hooked up with hdmi and my amp is optical digital. the trueDolbyD setting is not out putting to my amp only pcm...im getting DD with all the other languages but not the english 5.1 trueDD..do u think this could be a fault with the disk or does this true5.1 only out put through hdmi...i really hope it just a disk fault as im sure most blu-rays come with this trueDD....any help would be greatly appreciated..many thanks...Z