I’ve googled until my finger is bruised! I have a nice system for my room. There are times when I need to be quiet. I’d like to listen to my iPhone XR. I realize it’s a limitation. 
Does the XR have a DAC given the lack of headphone jack? Is it more important to get an amp or dac first? Is the best solution a combo? I’d like a tube amp just to play with. The setup doesn’t have to be portable. 
Any info and product suggestions welcomed. My first post, be gentle.