How loud is “loud". If you are exceeding ARC's maximum power limit, ARC will reduce Volume as a protective measure.
Might be helpful to know what speakers the Amp is driving, in terms of ohms and wattage required, too.
Hi @Mr. Thomas,
I’ve had a look into your diagnostics and don’t see any issue with the Sonos Amp. As @buzz suggested, Sonos devices will tend to lower volume to prevent any damage if a fault is occurring.
However, it looks like your Desktop controller is causing the issues here. From looking into the diagnostics, all lowering volume commands to the Amp came from the Desktop controller. The diagnostics shows that it’s on an older firmware version that your Sonos system and Android controller, so I suspect that may be what’s causing the issue.
I would recommend updating your Desktop controller or reinstalling if you aren’t able to update. I would also suggest your restart your PC to help clear up the memory and anything stored inside that could be causing issues. Since Windows 8, shut down has become Hybrid Shutdown unless changed in the system and will keep information stored in memory, so restarting your PC is preferable.
I hope this helps!