Sorry, I don't know what to suggest. Hopefully Dieter will respond. There is a ground wire that attaches to the case itself, is that connected I don't think that is the problem, but you should make sure it is connected.

If you bought this stuff new, you should contact Doepfer directly.

On Jul 6, 2013, at 11:26 PM, "isoldeandisobelle" < isoldeisobelle@... > wrote:

>
> It is version 2.
> --- In Doepfer_a100@yahoogroups.com , Nicholas Keller <maq163x2@...> wrote:
> >
> > Is it the torrid ring type (version 2) or the older black box type My old black box version 1 PSUs used to hum, but I've upgraded now.
> >
> > Nick
> >
> >
> > On Jul 6, 2013, at 6:31 PM, "isoldeandisobelle" <isoldeisobelle@...> wrote:
> >
> > > Hi gang -
> > >
> > > I have a 6U case and a 9U case, the 9U PSU hums (which changes in frequency when different modules are in use.) - the 6U does not do this.... is this ok
> > >
> > >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>


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