This type of argument comes up quite often. Class D vs A, AB,or Digital vs analog, or different speakers, amps, etc.
people have their opinions and there is nothing wrong with having an educated opinion. having an opinion with know what one is talking about is quite another thing.
I haven't seen one really wrong thing on the posts here. people just have opinions. Some based on equipment that they have heard and others on their past experiences.
Class D has been around for quite some time. In car audio it was really the only way to go to get the power output needed. you can't do it from 12 VDC. So switching power supplies were mandatory, and there was/is/are some quite good car audio amps out there.
Home audio was quite another thing. switching noise was a serious problem. Finding output devices that could handle the high frequency switching with low/no noise was hard and people could hear it.
Now, Class D has for home audio has come a long way. No way Jeff Rowland would delve into Class D if he couldn't do it right. I spoke with Jeff Rowland at the 2018 RMAF about this and he told me that they will always produce non class D amps.
Could be market forces for both classes at work.
Many homes simply don't have the space for large amplifiers and audio systems. Period. That forces the manufacturers to come up with serious alternatives. Class D was that alternative. However, back in the day, doing direct comparisons between standard Class A/AB amps and Class D amps with the same system and music, the Class A/AB amps won hands down.
That's not the case anymore.
Remember, back in the day, Class D was simply not very good. The power supplies and devices were not "there" yet. So, to get proper class A/AB amps right, proper power supply design was absolutely necessary. skimping on power supply design automatically determined that the amp would be bad.
This was why amps weighed so much. read Nelson Pass' articles on power supply design. Large transformers (read heavy) were mandatory, proper filter caps (also heavy) and lastly, proper power supply regulation (almost as complex and heavy as the power supply) were required. It almost came down to a certain weight per Watt value.
manufacturers didn't' do that for the hell of it. for proper amp design, it was mandatory.
Class D amps gets one away from very large/heavy power supply designs. That is not to say that certain manufacturers won't still make the casings extremely heavy, or the heat sinks, etc.
The problem also arises in that most manufacturers don't make their own transistors and tubes. They have to source them from others. So you either buy from what is available or you design based on your specs and get companies to make them for you to your specs.
My point is that Class D isn't necessarily the future. It is "a" future. There will be other technology coming that will supplant class D also.
But, if you think Class A or AB is going away, don't bet on that.
Space limitations, size, savings on power supply design and costs are the driving forces behind class D.
I've heard some pretty darn good class D equipment. What I don't understand (actually I do) is why they are priced so high. They don't have the extremely expensive power supply and heat sinks, so where is the expense?
But are they good? yes? Better that like valued Class A or AB? not so sure. some yes, some no. Same can be said for Class A or AB.
Are the top of the line (costs no object) Class D amps equal to or better than the top of the line (costs no object) Class A or AB amps? that I seriously doubt at this time.
But, one never knows do one?
But, stop dissing Class A or Class AB amps. The massive weight and size. Power supply design and massive heat sinking and regulation dictated this was necessary. Class D was not good back then. So, if manufacturers have they plants already set up for Class A/AB and costs is minimized, why change immediately? Many are very slowly moving to Class D, but they aren't getting rid of Class A or AB.
sorry for the long rant, but I noticed many getting very heated and I felt a need to slow things down.
If you have no space and don't want large heavy space heaters and you want very nice/decent sound, Class D is the way to go.
But if space isn't an issue for me, I would have to hear the Class D amps side by side against the Class A/AB amps before I make the switch. Get that, "switch". just a joke.
enjoy