How much do you really want to invest in enhancing something that in all probability cost the manufacturer under $25 to produce?
I think everyone should see the PowerWave as a tiny harbinger of future times: BIG performance from small, inexpensive stuff. --I recently noticed a 150GB FireWire HD on sale for $159, it was small and cheap, but with cavernous storage abilities. Amazing value and utility...
Used with reasonably efficient speakers, the PW is to me the mimicking "ventriloquist" of a very good tube amp, a tiny, impersonal, and inert one, -but one I can stick in my back pocket. (It conjures up an interesting mental image, no?) --
Bottom line to me is that this little curiosity does, let's say about 80% of what my absolute all time favorite amp did, (Art Audio Jota,) at 1/65 the cost!!! ......And from about 150Hz down, the Jota did about 50% of what the PowerWave does.