> Hello,
>
> Question not related to sound or DC ripples, but to electrical bills and power consumption:
>
> As far as I understood, the PSU 3 leaves behind the massive toroid and adopts a switching mode followed by the same
> “linear” regulatory circuit.
> Any “purely” linear rectifying PSU -like PSU2- is generally the least energy efficient converter from AC to DC.
> Switching mode power supplies are supposed to be way more efficient.
>
> I am probably not the only one who worries about the carbon footprint of their modular activity in general.
> The question then is: PSU3 vs. PSU2, are we talking about a third more efficient, a quater… Is it worth changing it over
> energy consumption
> (On the very long run: will the difference in electrical bill pay for the upgrade )
>
> Thanks.
>
> J.

The A-100PSU3 is definitely greener than the PSU2. The efficiency is about 70-80% (depends upon the load). The efficiency of the
switching supply is about 85% but the linear regulation eats up a bit because 3V are converted into heat because of the 15V->12V
linear regulation. At the max. current (2A) the loss is about 6W (3V*2A). For lower currents (i.e. not full 2A load) the loss is
smaller.
We also tried several "pure" 12V switching supplies from different manufacturers but were not satisfied with the quality (we still
offer them on our special list if anybody is interested). That's why we added the old-fashioned linear regulation.

Best wishes
Dieter Doepfer