FWIW my amp just arrived from U.S. Amazon.
Ordered Jan. 4 when Amazon was saying "arrives Jan 18-23" and they kept their commitment (barely)
build date 20240113
pcb v5
No obvious coil whine.
If I place my ear directly on the case, with no music playing & no speakers connected, I can just barely hear a very quiet "clicking" type sound from the interior.
The USB drive functionality is a little unstable. Sometimes USB shows up as a source option in the app, sometimes it doesn't. My ~ 1500 albums seemed to get fully indexed, but even Wiim has left me dumbfounded with their sorting by song artist rather than album artist. Same dumb choice that Pioneer makes in their head units. I had hopes that Wiim would be more sophisticated in this regard. Very disappointing.
Anyone happen to know if Wiim's sorting looks at the "artist sort" field in the metadata (as opposed to "artist" field) when sorting/indexing? I have an application that could xfer album artist data into the artist sort field, which would force the Wiim Amp to defacto sort by album artist. IF their sort uses that field. Or if Wiim provided for different sorts in the settings (which, afaik, they don't). I'll probably need to register on the Wiim forums to work this out, but thought it was worth a mention here.