I have a 4630. Setup was hdmi to older Samsung tv then optical out of that to receiver. I was only getting stereo so I bought a audio extractor I guess you would call it. Plugged the Roku into that used the optical out to receiver and hdmi to tv but still only get stereo. If the 4640 decodes dd+ to dd I would think the 4630 would as well?
Nope, the 4630 is the Premiere+. Only the Ultra 4640 and 4800/4802 models have the DD encoder. While optical audio is technically capable of bitstreaming DD+, most devices won't do it. The only way you'll get more than stereo sound is to send the audio to the AVR via HDMI. This is from the Wiki post for DD+ :
However, the S/PDIF interface has insufficient bandwidth to transport Dolby Digital Plus (E-AC-3)
bitstreams at the 3.0Mbit/s datarate specified by HD DVD; lower datarates are possible.
So, in reality very few devices will offer DD+ over optical, as it is out of spec for the optical connection. It looks like it's time for an AVR upgrade for you. Considering you can get an inexpensive AVR that supports all the lossless codecs, including TrueHD/Atmos and DTS-MA/:X for only a few hundred, it might make sense to get one with as much capabilities as possible, future proof if nothing else. When I picked up the Yamaha I have in my family room, I had no need for Atmos or Dolby Vision support, as I didn't have the speakers or display to support either. Since then, I added a couple of speakers pointed at the ceiling (to get two channel Atmos/DTS:X) and have also added a DV capable TV, so it was a smart buy on my part.
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