I've got three of the portable cases sitting in front of me, and
even with all the computers off, the only way I can hear any hum is
to put my ear about an inch away from the side of the case where the
PSU is. But then, I may have very little hearing left after all
these years of misuse.

--- In Doepfer_a100@yahoogroups.com , "p. hendricks" <ph@c...> wrote:
> ok, I stated mine didn't hum... everyone else said they did... so
turned
> everything else off and I double checked and there is a slight
hum. Very
> slight. Not really a buzz, I've had wall-wart power supplies go
bad where
> they start buzzing, but this is just slight hum.
>
> best,
> pH