said by csiemers:
For my setup I do this:
Roku -> HDMI -> TV -> Toslink -> Receiver
You could do this as csiemers has. However as TimCo correctly points out you will not get 5.1 at your receiver this way. TV sets do not pass 5.1 audio through them. You will only get a mixed down 2 channel stereo using this set up.
The newer ROKU units do not have toslink output. I find this to be a bad design. People in your situation are SOL for surround options.
You could look for an older model ROKU.
Mine is about two years old and has TOSLINK output. It also has HDMI, Composite and component video as well as red/white stereo outputs.
As a side note if you are looking for 5.1 from netflix on ROKU...
Even though I have my ROKU set up properly for 5.1 audio, I DO NOT get anything from netflix as 5.1. Even the titles that come across as HD. The sound I get from netflix is limited to simple pro-logic type surround and not actual 5.1 audio.
I know this is a netflix issue and not with my set up or equipment. I know this because titles I stream from the same ROKU over Amazon do in fact come across as 5.1 audio.
So either netflix is not sending a 5.1 audio stream or there is something else limiting it over the connection.