I do not know the exact specs of Deezer on Roku, but the interface is on the TV screen. Regarding my budget for the streamer, I was thinking under $1500.00.
Audiophile...in this case...CD quality.
Source...Deezer & Spotify...what are you getting with Deezer? If you have the Hifi subscription...($19.99 a mo) you are getting 16/44 files most likely (CD quality).
Premium ($9.99) these compressed mp3 files, and the free service is an even more compressed mp3 file....this is according to the Deezer website.
Streamers...Many of the music specific streamers in the moderate price range such as Blue Node 2i, can pass 16/44 and in some case hi-res files. If you intend to stream primarily via 3rd party streaming services (such as Deezer)...the Blue Node2i would be my suggestion. Even if you wanted to include your own library (hi res files such as DSD) you can play them back vis the blue node 2i if the files were on a laptop or a hard drive..
The drawbacks...it won't process multi-ch music and it doesn't have storage for your own library.
For <$600 this is a very good option...especially if Deezer and Spotify are going to be the main sources.
Interface...I don't own a Blue Node2i so I can't vouch for the interface, but I can say in general and I'm repeating what I saw another poster say, but it's true...Most of these streamer interfaces are designed for tablets or phones, and the tablets that I have seen functioning with Roon/Qobuz imo are pretty awesome.
To have the interface on a TV...I'm not that techie, but it's possible for some smart TVs.
I've been researching music streamers for a good while now in the <$2000 price range and all have pros and cons so you really have to dig into them, but the Salk Streamplayer Gen 3 checks off more boxes than any other for me and it's roughly $1300-$1500 depending on you configurate it. It has no playback limitations and you can store your own library on it as well....both big checks for me.
The draw back of the stream player Gen 3 is there's no DAC, but you can use the DAC on your AVR...in my case I think I will connect it via the Oppo 205 and use the dac in it.
But...before I would go spending any money...figure out what is being piped in...because if you're getting mp3 files from Deezer and Spotify...you might not improve much on SQ with an expensive music streamer.