Noob question about streaming . . .

I don’t think you should pay for another DAC, but I do think it’s worth it to have direct streaming of Qobuz or Tidal that doesn’t involve a tablet or phone as an intermediary. I have Roon and while it’s OK, I find the overhead of keeping another server, and paying for it as yet another subscription kind of burdensome. If I didn’t have so much music on disk I’d probably give it up for something simpler.

IMHO, you want a little box with Ethernet on one side, and S/PDIF on the other.  You could get a combined streamer/DAC, which would improve the digital resolution you can download also.

Here is one example, so I’d say don’t spend more than the ifi Zen streamer.

You should be able to stream Tidal through HEOS in your Marantz. I have no direct experience with HEOS, but most reviews I've seen consider it inferior to the Wiim or Bluesound software. Try it, and if it works fine with your Tidal subscription, then leave it be. Note that Tidal also has Tidal Connect which allows you to use their app as a controller, which is usually preferred by many users over their streamer's software. I don't believe that HEOS supports Tidal Connect.

The advantage of the Wiim streamer over HEOS would be a better software suite and the ability to use Tidal Connect.

In a nutshell:

#1 A different streamer would possibly provide for a better software than HEOS to control your music access but if you are OK with it, then there is no need to change.

#2 Tidal Connect is merely being able to use Tidal, with the interface you see from your computer or mobile device, Tidal connect sounds the same as Tidal through HEOS, It's the interface that changes , the streamer and built in DAC detrmine sound quality.

#3 Roon is yet another interface. It integrates Tidal and any music files you have on a hard drive or server plus has way better functions and album/artist information but requires  separate computer or hardware to run it, and what is called an endpoint, which means a streamer that is compatible with ROON. It is also subscription based.

#4 I have no direct experience with your Marantz but the DAC has more iof an effect on the sound than the streamer until you spend the big dollars.

#5 You are not likely to hear what a better DAC and streamer will do until you upgrade your speakers so until then, Getting a Wiim streamer would only improve how you access Tidal.

With your current speakers I’d evaluate if you hear a meaningful improvement with Tidal over HEOS, and if you do just stick with that but if you don’t just drop Tidal and stick with Spotify with HEOS.  I wouldn’t bother with a separate streamer until you decide to upgrade your speakers.

I believe with HEOS you are able to access the Amazon Music Service.  I found it provided a better quality than Spotify with pretty much the same access to about any music you should choose to listen too.  I never had a HEOS so I could be mistaken but the other side is I believe that you'll get a more noticeable  change in sound with a better DAC than a different streamer.