The Future of Audio Amplification

@georgehifi 

Thanks for posting that! 

Foggythink,

In a Class A or AB amp, the filter caps need only respond to the ripple demands resulting from an audio signal. In an SMP for a class D amp, caps need to respond to switching action up in the ball park of a good fraction of a megahertz. They need to exhibit very high ripple current ratings and extremely low equivalent series resistance. Electrolytic caps aren't famous for having exceptionally low ESR, but they're the only technology that's compact enough to provide the current capacity required. The sub-optimal ESR leads to internal heating of the capacitor. The heat dries them out, the ESR rises, that causes them to make more heat, they begin leaking electrically, and they eventually just short out and start frying silicon. 

Nobody will be calling any class D amp "legendary" 10 years after it was sold. They'll all be in landfills. The ONLY amps sold today that will still be around in 20 years will be class A and AB amps, and they'll still sound very good. 

Nobody will be calling any class D amp "legendary" 10 years after it was sold. They’ll all be in landfills.

Correct, not only do they sound questionable to many, but owners will be cursing the day they purchased them.
As replacement boards will not only be obsolete, but very expensive if NOS in stock.
As no one will be able to fix them down to component level economically, 4 layer pcb, double sided componentry, and all smd! all squashed into the size of a pack of cards, good luck !!!

Cheers George

So funny and incorrect.  All class D modules produced by the major companies 10 years ago are still available.  Example:  Here is the module that was sold in 2007 being sold now through Parts Express....
https://www.parts-express.com/icepower-1000asp-class-d-audio-amplifier-with-power-supply-module-1-x-...

But why would you want to replace your module on your 10 year old $2000 amp when you can buy a brand new better sounding stereo amp for a little over $1000 delivered?

There are guys buying super expensive class A amps right now that will be turning them around to get the latest new one in a year or so and lose $10,000 or more in the process.  Some of the best sounding newest class D amps are so good and so cheap that you could just throw them away (or sell or give to your kids or use in secondary system, etc.) in a few years when a better one comes out.  Never heard anyone cursing their inexpensive class D amp when it is no longer the latest thing.  I think the rich guys do more cursing and also more straining.....lifting those beast of amps!  I read a lot of reviews of the latest class a and a/b amps and it looks like the latest ones (and also getting more expensive every year as well) are really way better than those old amps that are 10 years old.  All classes of amps are way better today than ever.  Lets all sing along:  "Who wants yesterdays papers?.....Who wants yesterdays amps?....nobody in the world"

There are many class D amps out there.....some sound eh....some sound middling, some sound very good and some sound really great.  Just like anything, you need to do your research and buy from someone who gives a trial period......but the same is true with any class of amp.

 newest class D amps are so good and so cheap that you could just throw them away

That's just great, depends just how well off you are. Try saying this to an owner who Class-D has just smoked it, as see what you get back in return.
Also you sell them, so you and are definitely not impartial.

newest class D amps are so good and so cheap that you could just throw them away

What a wonderful throwaway society we now live in when we can even consider that statement as not only being relevant but likely the truth.
Very sad reflection of todays mindset and the times.