Hi Javier,
Thanks for the detailed report, and especially for testing across several devices. That already narrows things down a lot.
The fact that the same files play bit perfect on the Primare tells us the DSD side of Serento is doing its job. So this looks like something specific to how the Naim negotiates DSD over UPnP, rather than a general problem.
One thing worth setting aside first: the Roon comparison doesn’t tell us much here, even though it feels like it should. Roon doesn’t use UPnP at all. It uses RAAT, its own protocol, and the Roon Core prepares the stream itself before sending it. So “works in Roon” confirms your Atom is Roon Ready, but says nothing about whether it accepts DSD over UPnP. Different path entirely.
Could you check a few things for me?
1. What DSD rate are these files?
This is the most likely answer. Naim officially supports DSD64 and DSD128 only over UPnP. If your files are DSD256 or higher, the Atom will refuse them, which would explain why they play fine on the Primare and on your iPhone and Mac, where Serento decodes them itself.
2. Which UPnP server are you using?
And does it have any DSD related settings? Several servers have a “DSD support” toggle and a “compatibility mode”, and Naim streamers are known to be particular about both. Users on other forums have had to get that combination just right before their Atom HE would accept DSD.
If your server has those options, worth trying: compatibility mode off, DSD support on.
3. Do the same files play from the Naim app itself?
Same server, same files, but browsing through the Focal & Naim app instead of Serento. This is the useful test. If the Naim app can’t play them either, we know it’s the streamer or the server rather than anything I need to fix. If the Naim app does play them, then I have something concrete to chase.
One more thing that would help a lot if you’re willing: does the Atom show any message at all when you hit play, or does it just sit there silently? Even a brief flash on the display is a clue.
I’d rather get to the bottom of this properly than guess, so thanks for bearing with the questions. If it turns out to be something in how Serento talks to Naim streamers, I’ll get it fixed. I ship updates every couple of weeks.
Also, as a last resort. If you go into Settings - Logs you can enable logging that helps me debug issues. While that option is turned on close the app completely, open it again and try playing some DSD files on the Naim. After that go back to Settings - Logs and press Send Logs and the log file will be sent to me and I can have a look at it. You can turn off logs after all this. Thanks.