Heck, I've got a Astron RS-30a under my desk that is noiser than hell
and has been since I bought it WAY back when. :)

The noise of an offline switcher could be as loud as these. But this will be
at 10-20 Kilo Herz. The possibilty to vacuum
inject epoxy is the same with standard transformers as with high frequency
switch mode transformers.

michael