Appreciate the explanation! And my apologies, I did not mean to presume it being a design flaw, but to emphasize that all units behave consistently, meaning it being normal (or not) for all units and not related to a fault in the setup.sign flaw. We've implemented rigorous safety measures, and the device has passed all necessary safety certifications (based on IEC 62368-1 safety requirements), ensuring that the sensation is completely safe, albeit potentially irritating. This phenomenon is more common in 220V systems, typical in Europe and Asia, than in the 110V systems used in North America.
Regarding "as can you" - well, for most of my Amps I'm just playing music on some bookshelf speakers, using a WiFi source, so there's nothing nearby to connect to.
However, as long as it's indeed safe and normal, this doesn't bother me.
Thanks also to support for pointing out that it indeed _is_ both safe and normal.