I am going to assume the receiver has an coaxial audio input (the spec. says 1(RCA):5.1 surround). The 420 has a coaxial output (label item 6) on the manual I saw. Try hooking that up..good luck (hope it works).
I own a new Toshiba 32c100u2 lcd television and a dr420ku video player/recorder. They are connected with a good quality hdmi cable. The units work fine for playback. However, I want to send the audio through a Technics Sa-dx940 stereo receiver to the external speakers. The audio plays thru the TV speakers only. I cannot direct the audio thru the receiver, despite several different hookups.. Suggestions?