Class D vs AB vs A. Which sounds best?
Short answer: it depends.
A lot of people often assume that the higher the class amplifier the better the sound quality, but this is not always true. For such an assumption to be correct you would also have to assume that the class D amplifier designer had the same intentions of creating high quality sound, took the same amount of care in the layout, choice of components, and had the same amount of expertise as the designer who made the other topologies. This is rarely the case however.
It’s no wonder that class D amplifiers have received so much hate by people who are particularly demanding of their audio quality when you consider that the vast majority of such amps produced are of meager quality. But If the margarita is bad blame the bartender not the drink. Just sayin.
The fact is that class D amplifiers have incredible potential and if done right by excellent engineering can get extremely close to matching the best class A or AB amplifiers on the market. Similarly no “topology type” can make up for poor engineering which is why I can’t say that class A or AB is “always” or “definitively” better than class D. It just depends. However with all things being equal in the expertise and intentions of highest possible sound quality , yes a class A or AB can generally be a little better than class D. But not by much and you’d be hard pressed to notice the difference when class D is done “right”.