To say Ralph,
' he buys the modules does a small mod so it can be said to be better, throws in in a box, and there’s his beer money',is a bit harsh and uncalled for.
To the contrary, his amps are quite stable for a wide range of speakers.
Those speakers with low impedance are difficult to drive even in SS.
Regarding Class D amps:
In fact, I have spoken to him about it and he seems to have come up with an ingenious way to deal with switching issues.
Bob