Sonos Amp buzzing

Yeah I’ve tried moving it to different surfaces. It’s usually on a solid wooden table, but sitting it on the carpet makes no difference. It’s an internal electrical sounding hum/buzz.

Yeah I could do that but I find the noise to be a bit disconcerting. I worry its a fire risk. That’s probably not the case but that’s how abnormal it sounds.

Of course we don’t know exactly what is going on inside the unit, but it is not likely to be a fire risk. Usually this sort of issue is a physical breakdown of a transformer or coil

As the name implies these parts are a coil of wire, wound close together. Efficiency can be improved if the coil is wound on an iron “core”. Efficiency can be further improved if this core is a collection of laminated iron slides, rather than a single piece of iron. As current flows in a wire, there is a magnetic field, and forces. Since there are mechanical forces, the slides can vibrate unless tightly clamped together. Sometimes this clamp deteriorates and the vibration becomes painfully audible.

While this is a typical failure, it does not exhaust the possibilities. Another possibility is that an internal component might be drawing more current than expected, overpowering the clamp. In this is case, I expect that there will be a complete shutdown soon.

This could be a relatively straightforward DIY repair for you or a friend. You could purchase a failed “for parts” unit — that hopefully is not on the same track as your unit — then scavenge your part. Note that SONOS will not accept a unit for the 30% credit if the unit has been dissembled.

DYI is at your own risk, the internal voltages are deadly if you put a finger in the wrong place.

If you don’t know your way around inside consumer electronics seek out a skilled friend.