I've been having a very good experience with the FiiO SR-11 ($109) as a Roon endpoint, working via WiFi. It is significantly better than using a Raspberry Pi, iFi Zen Stream, or WiiM device.
1. It has an excellent USB digital output. This allows me to use a variety of good DACs and handle all sample rates up to DSD 128 (although the specs say 256, Roon reports 128 as the max.). I am currently using the FiiO K11 R2R DAC and headphone amp.
2. The WiFi connection has been stable and flawless. It can connect at 2.4 or 5 GHz. I've had no dropouts, hesitation, or clicking issues, unlike my experience with a Raspberry Pi 4. It also has an Ethernet input. These connections persist without issue when it's powered off and on.
3. It is Roon Ready, so it's using Roon's RAAT network protocol and not just visible in Roon as an AirPlay device. This benefits sound quality in my experience.
4. It has an external power supply with a USB-C connector. The supplied wall wart sounds very good, and a 5v linear power supply sounds even better (moving beyond cheap and cheerful but suggesting good design choices internally that limit self noise).
5. It has a dedicated Roon-only mode. As shipped, it is looking for Roon or Airplay or DLNA connections (with current firmware), but it can be set to be Roon only, eliminating CPU cycles wasted on the other stuff.
6. It is sturdy, compact, and runs barely above room temperature. Once it is set to Roon mode, USB output, digital volume control disabled, and connected to the network it stays configured and does not need attention. Whether you pull the power cable out of the back, put it in standby mode, or have a power outage it just turns itself on and gets back to work without further fiddling.
I have not tried Airplay. I have not tried DLNA or connecting a hard drive or memory stick to the USB-A port on the back. It seems as if Spotify, Apple Music, Qobuz, or Tidal are simply handled via AirPlay from the device controlling the music (phone, tablet, computer). Customer support seems obtuse, although it's possible to find a page for firmware. Mine, ordered from FiiO via Amazon, came with the current firmware, and it doesn't look like they update it often (unlike WiiM or Eversolo). That's a good thing, in this case.
It is by far the best cheap and cheerful way I've found to plop a reliable Roon endpoint anywhere I want it and get good sound with nothing compromised or disruptive to my ear.
