Just tried PSU at work and it's not silent, but I think better than the other one - I seemed to have go get a bit closer to hear it - my other one I could hear 2m away. Of course, my home and work may have equally poor mains, or the hum at work is 'normal' (and I'm just over sensitive) and it's worse at home - in which case a filter may be the way to go.

So I'm hoping to take Nick up on his offer and try it at his place. That will also give a second opinion and a point of reference.

Difficult to judge from work environment, but if the PSU was on my bedside table at night, it would be audible.

Meridian owner since 1992
Prime & PSU, Focal Elear headphones, Roon (ROCK 8Gi5 NUC), Explorer 1 & 2, F80. 200/203, various Sonos (via Roon).