· I am using Roon Arc 1.81.424 (425) on iOS 26.7 on an iPhone 17 Pro Max connected to a Quloos MUB5 DAC/AMP.
I am using the latest production build of Roon Server/Core on a sonicTransporter i7.
In general everything works fine and I am happy with the results. When I switch to using Sample Rate Conversion set to a fixed rate of DSD256 (DoP), I think there is a clear improvement in the audio quality, which I am happy about. However, I often — but not always — encounter brief drop-outs in audio that may last about a second or I hear a terrible scratching/squelching sound (that reminds me of a needle scraping and jumping across a record).
I have experienced this with music streamed from Tidal or Qobuz or stored locally on my iphone. Maybe — not certain — it is more reliable when I switch the phone into airplane mode and limit myself to downloaded albums.
Is this a limitation you are aware of? Is there anything I can do to improve the reliability? It almost seems as though Arc has not buffered enough of the audio stream before handing on to the USB output.
Tell us about your home network
· Home network is all Unifi with ethernet backhauls for each wifi access point. Roon Server/Core is wired. The Arc remote access relevant for this issue is over every type of connection — in the home, over various VPNs, over 5G, from different countries, fiber networks, etc.
Thank you for your post and our apologies for the delay in responding.
There are no known limitations with ARC that would cause audible artifacts. If ARC encountered an error with buffering or transcoding, playback would tear down.
Can you please share a screenshot of the Signal Path under the configuration with which you’re experiencing these issues? This will be transparent to the actual digital chain as the vendor DAC firmware reports it to ARC. Any transcoding performed on Roon’s side will be displayed.
Please also list the name of a track that recently exhibited these issues. Do they occur at the same point in the track each time?
The issues — random brief gaps + distortions — happen with any album and any format. Streamed and/or downloaded.
I have attached three sample Source Paths, each reflecting a different source format. I also attached a photo of the screen of the MUB5 that confirms that it is receiving DSD256.
Interestingly, I noticed that when I take screenshots when listening with SRC to DSD256, I hear a screeching sound through my earphones. On the other hand, when listening to PCM — with or without SRC — the screenshot action is silent. Also, if I receive an incoming message that triggers a sound (WhatsApp, for example), it squawks, whereas with PCM the audi on temporarily reduces in volume. It sounds like DSD is not preserving the exclusive mode…
