3 1/2 yrs later, I could not resist. Of course there are Class D amps out there that are "just as good" as Class A amps....just like there are Hyundai autos out there that are "just as good" as a Ferrari.
@jymc Ferrari was founded in 1939. If you're comparing nearly any Hyundai against an older Ferrari, you might be disappointed that the Hyundai not only was faster but also requires far less maintenance.
Now let's put this in perspective as pertains to audio. Class A was the first and only class of operation created over 100 years ago. Class D was proposed in the 1950s and the first commercial home audio class D amps were sold in the 1960s. Now I'm sure you understand that in the 1960s germanium transistors were pretty much the only game in town and had really seriously terrible performance. But better transistors came along and class A solid state became possible. Meanwhile, better transistors came along and class D got a lot better. Meanwhile, cars made in the 1960s were lucky to get 100,000 miles on them before falling completely apart; Do you get my point?
Class D has evolved not only due to breakthroughs in how to do it, but also vast improvements in the semiconductors with which to do it.
So the bottom line these days is if the class D amp is built to high quality standards it can easily rival or surpass class A. Class A is used to minimize distortion in the output section due to non-linearities in the output devices, class D relies on switching so output section linearity isn't a thing. Try a good class D amp sometime and you may not want to go back.
