You can get an AV cable that outputs optical 5.1 audio and component videohttp://www.amazon.co.uk/gp/product/B002UJ3CVI/ref=pd_lpo_k2_dp_sr_3?pf_rd_p=471057153&pf_rd_s=lpo-top-stripe&pf_rd_t=201&pf_rd_i=B000CO1F5S&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_r=1CBW91YH9KF4J0WD1AWEThis feeds your 5.1 amp.
It will also carry 5.1 Dolby Surround.