Questions about older receiver compatibility with newer tv

[Bear&Buffalo]

Hello everyone!
So I have a 4K Samsung Tv, and an Xbox One X. I want to be able to use my Yamaha HTR-5950 receiver which is a few years old.
The receiver does not have any HDMI ports, but does have optical.
From what I understand, I should just be able to do, XBOX>HDMI>TV, and then RECIEVER>OPTICAL>TV.
I guess my question is what else do I need to be aware of, and is that all I need to have my sound system working with my tv? Will the older Yamaha be compatible with just optical or do I need some sort of adapter, and will I be loosing/downgrading any 4K quality by doing this method? I am not concerned with newer things such as Dolby Atmos, I just want to be able to utilize my 5.0 surround system.

 

[lovinthehd]

Some tvs don't pass but 2.0 out, altho optical itself is capable of 5.1 lossy codecs if the tv will pass it out such a signal. The Yamaha should have no problem if the tv passes out 5.1 lossy from the tv. Some source units could also pass audio directly to the avr via a secondary digital connection while you route video to the tv. Maybe if you post up your model of tv then someone may confirm....I have an older Samsung tv, not 4k and it only passes out 2.0 except for OTA content where it can do 5.1.