Hi. You mentioned your Integra DTR-30.5 which (at least in your signature) is paired with a Sony KDL-40Z5100, but I'm assuming that you're talking about your Sony XBR. The Sony XBR certainly does have ARC, and the XBR manual specifically states on page 14 that the optical cable is only needed if your receiver doesn't have ARC. So, with the XBR, you just need the HDMI connection and won't need the optical cable.