Streaming

Tidal has one of the worst cataloging systems of all the streaming companies.
You literally have to:
1. Type the composer in the search box
2. Add the type of music (symphony/concerto/etc.) after the name.

You then get hits for albums most of the time.
Spotify has a much better organized catalog, and more complete, too.
Spotify also has a nice little 'Discover' tab that offers music related to what you have been listening to. I discovered lots of interesting new composer using that as well as 'Related Artists' when searching an artist.

FWIW, though you can get higher sampling rates on Tidal on some recordings (like MQA), most of their offerings are at the same 44Khz that Spotify outputs.
@willemj .
I believe he is using the OPPO to connect to the Tidal App. on his Ipad and then outputting to his Schiit Dac.
B

Unfortunately, I have no way of connecting Spotify to my system by WiFi as I can do with Tidal.  Oppo has the Tidal app bundled with it, and I’m streaming through the Oppo. What’s worse is I can’t connect any device to my Gungnir DAC because (just a couple of months after I bought it,) the outlet for the optical cable broke. The outlet won’t hold the cable in tightly.  A washer broke off from the outlet. 
So, at this point, if I want to stream, I’m stuck with Tidal.

I haven’t wanted to send the DAC out for repair, because I’m experimenting with different tubes, and besides, I’m enjoying the system far too much.

OK. This means you are using the DAC in the Oppo, which is fine. You could even use the Oppo as a very good pre amplifier and connect it directly to your power amplifier. However, on the Oppo you only have a Tidal App and nothing for other services. Fortunately the Oppo has an optical input as well, so you could simply get yourself for example a Chromecast Audio for some $30, plus a basic $10 optical cable (with mini plug at the Chromecast end), plug it into the Oppo, and you will have access to whatever streaming service you like, and with very good audio quality. Searching for the music you want is easier if you use a tablet rather than the small screen of a smartphone.

Yes, thank you, I didn’t think of that.  The Oppo could be used as a DAC.
How do you then access the other streaming services?