Welcome to the club.
You could still be using your TX-SR500, but you need to get a new Blu-ray player, like the Panasonic BD80. Then, you connect the multichannel analog outputs from it to your receiver 5.1-channel inputs.
* But, you'll do much better with a new Denon A/V receiver in your price range, that have all the internal audio decoders, including Dolby TrueHD & DTS HD MA.