Do I even need a dedicated stereo preamp?

So far I am incredibly happy with my setup. However, a part of me wonders if I would gain any sonic benefit from a dedicated preamp. 

In a word, YES!!!  One of my biggest “Aha” moments in audio was in going from using my prepro to a dedicated stereo preamp that firmly disabused me of minimizing the importance of a good preamp, and since you’re using the preamp section of a $1900 AVR your upside potential is considerable.  If you share what sound characteristics are most important to you and/or what specific improvements you’d like to achieve you’ll get good recommendations here.  Also budget and if you’re looking for new or used.  Last, if you can hook up your source to both the Anthem and the stereo preamp you need not lose the ability to adjust volume with your phone for less-critical listening. 

Thanks for responding so quickly! 

My audio journey is depressingly small yet chock full of research and admiration. I am only on my second pair of speakers, 1st being SVS ultra bookshelf and my current being Tekton Moabs. Insanely massive upgrade right there. I got the Anthem shortly after my SVS speakers arrived as my Denon AVR died. 

I was mostly curious about the new range of class D (low heat, good efficiency, low noise) which led me to the Buckeye and that alone felt a bit more transparent since Anthem is class A/B. I was using the internal DAC and streaming capabilities but it is chromecast only which is a bummer. So then I bought a Wiim Pro Plus which can use Tidal Connect, but I was having too many bugs with the Wiim. So I bought the Eversolo. I prefer the software in the Eversolo much more, less connection issues. Then I read about R2R’s and wanted to try the cyan and WOAH I am enjoying music more and more every day. 

I actually just went to Capital Audio Fest for the first time this past weekend. Makes me even more happy regarding my Tekton purchase as the community as a whole seems to hate Tekton’s. I went to nearly every room over the course of the day and only heard 3 better speakers, lowest of them being 67k lol. Granted the show had different room acoustics, speaker position, listener position, source, etc. so I know I don’t have the full picture. 

So overall, I suppose I prefer transparent, true to source, detail retrieving, big soundstage, good instrument separation. From the show I really don’t like bright as it hurts my ears (I don’t get that at home). That’s what got me looking at the Benchmark LA4 and the Holo Serene as they are both viewed as transparent without losing detail but man 3k right after I bought the cyan for 1400 is ROUGH. My ears want the best out of my speakers but my wallet wants me to stop thinking so much. 

The Anthem MRX 540 gets good reviews as a 2 channle preamp, my thinking is your going to have to spend much more to get "Better" if not a side step/difference. 

Tell your wallet to get a job. You need speaker supplies! Lol. 
https://www.schiit.com/products/freya-f

if you’re able to stay true to this hobby, you will be completely blown away in 10 years of what you are able to accomplish.