How to get Line Level Audio output using Audio Cape

Hi,

I am trying to get Line Level audio output from audio cape. I have connected RIGHT_ROP, RIGHT_ROM, LEFT_LOP, and LEFT_LOM to a stereo amplifier and connected the amplifier to the speaker.

When I send the command to play audio using

aplay file.wav

I just get noise on the speaker.

I am able to get audio on headphones, so I am sure device tree was loaded correctly and cape works fine.

How do I get audio on line out? Do I need to route audio to RIGHT_ROP, RIGHT_ROM, LEFT_LOP, and LEFT_LOM in the audio device tree overlay? If so how do I do that?

Thank you