Check the audio menu of your new TV to see if it will output in surround sound rather than just stereo. If it does then most likely your new TV has optical audio output. Your old Yamaha should have an optical input so just connect them. You can connect the BD player to the TV with HDMI. Optical audio can be converted to analog stereo if need be.http
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If the TV won't output in surround sound then you would want to add a connection from the BD player directly to the Yamaha. If you BD player has audio out then add that connection to the one from the TV. If not then you would need a HDMI audio extractor like this one...