Hi I just received my new Sony BDP-S760 to replace my PS3 as main blu-ray player. One of the main reasons (other than Play's £100 price offer!) was to make use of the multichannel outs as my Marantz SR5200 amp is now a little antiquated without HDMI or ability to decode HD sound. All hooked up now but for some reason when playing back I am getting nothing out of subwoofer though all other speakers working fine. When I go into Audio settings on player and run test signal all speakers emit the tone but nothing from the subwoofer though it does see it! When I switch to using optical cable everything works though obviously not in HDsound. Using the amps own test tone all speakers emit the test tone including the sub. Can anyone offer my advice on what might be wrong?