Claude, I believe that the new PSU Power Unit may be an external supercapacitor-based power supply that can be applied to deliver DC to Corus, Aeris, and the upcoming Criterion replacement. I do not have any details from JRDG, but knowing a little about supercapacitors, it is likely that PSU may yield a great deal of transient authority to applicable devices.
And just in case you were asking.... No, you can't apply PSU to any power amps.... Just not enough current for that.
G.