Mu-so Qb Hiss

Having a strange hissing problem with my Mu-so Qb. I have seen others report it, but no solutions to remedy it.

When I power the speaker on, it produces an extremely quiet hiss, at a level I would completely accept and is very very quiet. The hiss does not scale with the volume setting.

As soon as music is played, a much louder hiss is produced. It doesn’t matter what the source is, I’ve tested it with radio, analogue input and Spotify, they all produce the hiss. Again, it does not scale with volume, but it’s audible about three meters away when the music is quiet.

Have tried with different sockets and plug orientations. Convinced this isn’t hardware, as it appears to happen only after music is played.

Anyone else observed this and have any ideas?

To be honest it does sound like a hardware fault to me. You could try a factory reset (of the the firmware) but if that doesn’t solve it, then it probably needs a repair.

Do you use those internet over mains setups?

Not heard of this issue before. Sounds like hardware issue.

Is it new, and is the problem new? Also have you tried plugging it into a different electrical circuit, e.g. upstairs, or even a different house (if you can). Do you get the same issue if you play music off the USB drive?