I have a Humax Series 2 TiVo, and am trying to connect it's component video/audio output to a Yamaha RX-V665 home theater receiver input. The problem is that the two component video inputs (with the Y/Pb/Pr video connections) don't have a corresponding RCA audio inputs to match the TiVo outputs. One of them has an optical audio connection and the other has a single "coaxial" input for audio, neither of which the TiVo unit has. So how do I connect the red/white audio output from the TiVo to an audio input to match the video inputs?

I'll attach a picture of the receiver connections.