Yes, the 103 can accept 5.1 input on the HDMI inputs as traditional DD 5.1, DTS 5.1 or LPCM 5.1. And that will be output to the multi-channel Analog outputs just like any other 5.1 content you might play.
While viewing 5.1 content from your Dish box, press the Info button on the 103's remote (upper right of the Arrow buttons) and the OPPO's on-screen Info display will show you exactly what is coming in as the audio input format. If that's not 5.1 then there's a setting in your Dish that is incorrect. Typically the setting will let you choose whether digital audio output is LPCM or Bitstream (which may be identified as Dolby Digital). It is the Bitstream (or Dolby Digital) choice that you want. It is quite possible that the Dish box has separate settings for HDMI digital audio output and Optical digital audio output.
The LPCM setting from such boxes will typically force a stereo down-mix -- intended for direct connection to TVs that don't know how to handle 5.1 input.
Thanks for the answer above and for filling me in on where the info button is on the 103 remote. And yes it is getting 5.1 from my hdmi inputs, it is just getting the balance right on what volume control to use , whether to use the 103 volume control or the av receivers volume control. But what I found was that it is better to use the AV receivers volume control as I get more control over sound out put at a lower volume out put from the amp.
As when i was using the 103 volume control i would end up turn my amp out put to a high volume level so i would have a better range of volume from the 103 , but when you turn the volume down on the 103 the amp was still is at high out put so the volume would go down but then you could notice the static noise over your surround speakers because the volume was turn up so high on the amp .
it all a learning curve and thanks for your help