To koalais,

有關你的問題在 Dolby 的網站已有詳細解說。基本上，不管是 Dolby Digital(AC-3)或是 Pro Logic 都是以 Dolby Surround 為基礎，所以如果你的 DVD Player 支援 AC3 並可以以二聲道輸出(類比)，那你的 amp 就能表現 Pro Logic 的效果。以下是部分內容

Can I hear Dolby Digital programs over a regular stereo or Dolby Surround Pro Logic system?

Yes, you can use most of the new Dolby Digital program sources with your current play-back system, because they have Dolby Digital decoders built in to provide conventional analog
stereo outputs.However, to experience the thrilling 5.1-channel surround sound used on many Dolby Digital programs, you typically need a separate unit, such as an A/V receiver, that incorporates a 5.1-channel Dolby Digital decoder.