What are the reasons to choose Class A/AB/H over D in this day and age?

[Willem]

Not before my funeral, and even after that our engineers will be able to do a better job than just about anyone in the world. Research and planning are already taking place of course, because any measures will take a long time to implement. But it would be a pity if ultimately my grandchildren would have to return Amsterdam to the sea. So we are quite motivated to do something about climate change. Also, that would be a lot cheaper than building more dikes etc. Right now the wisdom of continued home construction in the lowest parts of the country is being discussed.

 

[Bob from Florida]

Not before my funeral, and even after that our engineers will be able to do a better job than just about anyone in the world. Research and planning are already taking place of course, because any measures will take a long time to implement. But it would be a pity if ultimately my grandchildren would have to return Amsterdam to the sea. So we are quite motivated to do something about climate change. Also, that would be a lot cheaper than building more dikes etc. Right now the wisdom of continued home construction in the lowest parts of the country is being discussed.

Let's make the assumption that temperatures will rise for some time. The second assumption is humans are largely responsible for the climate changing. Assuming all of this is true, the momentum of change is not going to stop on a dime. Should we be concerned? Yes. Do we disrupt everyones way of life in a drastic manner? No. We make positive changes to reduce our negative impact without radical disruption. We also adapt as needed. Perhaps your engineers will build a self-sufficient floating city where Amsterdam used to be - if it comes to that.

The real revolution in wasted power will be superconductors at room temperature......

 

[bravomail]

I'd just like to know technical reasons why there is still a place for A/B/AB/H in the future.

take Denon. why wouldn't they use Class D in their AVRs?

 

[Willem]

Should we be concerned? Yes. Do we disrupt everyones way of life in a drastic manner? No.

None of us want to disrupt our lives. The problem is that the cost of doing not enough is far greater than the cost of the energy transition. Do not forget, for example, that the vast majority of big cities in the world are along the coast. And the longer we wait to do something, the more disruptive either the crisis or the transition will be. On the other hand, the new challenges also provide new opportunities for jobs and technical innovation. That business is booming.
In the meantime, and to return to our original subject, class D is a small contribution, and the good ones like Hypex and Purifi also measure much better than nearly all traditional designs, and at a lower initial cost. As always, it is mostly technical innovation that drives economic growth.

 

[Jim Matthews]

take Denon. why wouldn't they use Class D in their AVRs?

If they have a dedicated production line, and produce much of the discrete components - there's no cost savings in retooling. If the buying public insists on a change in power supply topology, Matsushita will produce those gubbins, too.

Keep in mind the economy of scale here - there's considerably more product supporting video than audio and that's what drives production changes.

 

[Lambda]

Real high end audio is small market so there is not so mush innovation and developing going on.
Most of the R&D is making it as cheap as possible and barley good enough for the average customer.

Good enough for 98% of the customers and a view cents cheaper to make makes more profit then Good enough for 99% but more expensive to make.

Audio being more then good enough for almost everyone is a relative new development. therefore the shift to optimize for small, efficient and Cheap is also relatively new.

No matter of the Class of amplifier they can sound transparent or they can sound bad.
making a "ok" low power class d is super cheap today and it is "Good enough" for most applications.

Sure you can buy a "better" Class A. But if you don't here a difference thats as pointless as using an F1 car to go grocery shopping.

 

[antennaguru]

None of us want to disrupt our lives. The problem is that the cost of doing not enough is far greater than the cost of the energy transition. Do not forget, for example, that the vast majority of big cities in the world are along the coast. And the longer we wait to do something, the more disruptive either the crisis or the transition will be.

We're not going to change the Earth's climate, no matter what we humans do or how much sacrifice is instilled by the politics of it all. The sooner we face that fact the better we can realistically prepare for the future.

The fact is that our planet is currently experiencing what occurs during the tail end of an Ice Age (that we BTW are still in, as there are still glaciers present on Earth), an Ice Age that our planet has been coming out of for the last 10,000 years or so. One of many Ice Ages that preceded this one, but this one is the one that killed the dinosaurs - who would have already eaten us if they were still around.

If another large meteor hits our planet we go into possibly another cataclysmic Ice Age, and we go the way of the dinosaurs. If our eleven year sunspot cycle goes into a near century of lower sunspot activity and we have another mini Ice Age, like we experienced during the Maunder Minimum, there will be cooling - but by nothing that humans have effected. That scenario is actually forecasted by some scientists but is not a politically popular forecast. Humans are just so overtly bold to believe that they can influence an outcome that is entirely controlled by the power of the Sun and what can happen to a tiny little planet in our universe. Let's not forget that Earth has been here millions of years before humans came to be here on it. We are simply insignificant in the big picture...

 

[tmtomh]

We're not going to change the Earth's climate, no matter what we humans do or how much sacrifice is instilled by the politics of it all. The sooner we face that fact the better we can realistically prepare for the future.

The fact is that our planet is currently experiencing what occurs during the tail end of an Ice Age (that we BTW are still in, as there are still glaciers present on Earth), an Ice Age that our planet has been coming out of for the last 10,000 years or so. One of many Ice Ages that preceded this one, but this one is the one that killed the dinosaurs - who would have already eaten us if they were still around.

If another large meteor hits our planet we go into possibly another cataclysmic Ice Age, and we go the way of the dinosaurs. If our eleven year sunspot cycle goes into a near century of lower sunspot activity and we have another mini Ice Age, like we experienced during the Maunder Minimum, there will be cooling - but by nothing that humans have effected. That scenario is actually forecasted by some scientists but is not a politically popular forecast. Humans are just so overtly bold to believe that they can influence an outcome that is entirely controlled by the power of the Sun and what can happen to a tiny little planet in our universe. Let's not forget that Earth has been here millions of years before humans came to be here on it. We are simply insignificant in the big picture...

None of this changes the fact that the current round of warming of the earth's climate has indisputably been caused in large measure by human activity. In the context of the long history of the earth (including not only its past but also its future), we humans are indeed insignificant. But we have caused most of the current warming. The evidence for it is pretty overwhelming,

Oh, and however insignificant we are, our choices of amplifier topologies are even more insignificant.

Personally I have become a fan of Class D because the best Class D amps perform so well, cost a lot less than traditional elite/high-end amps, and run so much cooler than Class AB amps, which makes it a lot easier to stick them in a cabinet and not have to worry about thermals. But there are plenty of fantastic AB amps out there, and of course the hybrid designs like the Benchmark, so ultimately I'd say it's about measured performance regardless of topology. The energy-use issue is important, but in the aggregate I would imagine that hi-fi enthusiasts' amplifiers are just a rounding error in the total consumer/residential power-usage picture.

 

[ebslo]

We're not going to change the Earth's climate, no matter what we humans do or how much sacrifice is instilled by the politics of it all. The sooner we face that fact the better we can realistically prepare for the future.

Thanks, but I prefer to get my political disinformation from Infowars, not audio forums.

 

[flyzipper]

The reason, for me, is availability.

Sadly, the traditional technologies are what's widely available in some product segments (AV receivers, for example), from major vendors.

That said, I've enjoyed class D in car audio (for more than a decade), home theatre subwoofers, and studio monitors for quite some time (product segments where Class D is readily available).

 

[H-713]

Reality is that for most home users, the differences are negligible. Most audio amplifiers in a domestic environment spend most of their lives idling, and the idle power of most (not all) modern linear amps isn't all that much higher than that of their class D counterparts. Furthermore, if you're living in a place like Wisconsin or Minnesota that's a frozen wasteland for half the year, that heat output isn't necessarily a downside, since you're have to use some amount of energy to heat your living space regardless.


Where class D makes a ton of sense is in live sound. That's an application where the amplifiers do work hard, often outside during the hottest part of the year. That means they don't need the cooling systems of a class AB or class H amplifier, which saves weight. They also don't need as many generators, or as heavy a feeder cable. Weight saved cuts down on shipping costs and back injuries.

 

[H-713]

The real revolution in wasted power will be superconductors at room temperature......

I wouldn't hold out on room temperature superconductors being a practical thing any time soon.

 

[clearnfc]

If they have a dedicated production line, and produce much of the discrete components - there's no cost savings in retooling. If the buying public insists on a change in power supply topology, Matsushita will produce those gubbins, too.

Keep in mind the economy of scale here - there's considerably more product supporting video than audio and that's what drives production changes.

Yes, I agree on this. Economy of scale is very important as it is what drives down production cost and development. I have to say hifi industry is not high volume and the scale is simply not there to drive changes.

Any thing I feel is usage pattern. Eg. for myself, I am still using an old denon class A/B AVR. However, I don't use it everyday. Perhaps 6-8hrs a week? Its not going save much power compared to class D.

 

[Willem]

See here for what is happening in the courts: https://www.bbc.com/future/article/20211207-the-legal-battle-against-climate-change I have now said all I wanted to say on the subject of climate change, so for me it is back to music and music reproduction.

 

[Jim Matthews]

The fact is that our planet is currently experiencing what occurs during the tail end of an Ice Age (that we BTW are still in, as there are still glaciers present on Earth), an Ice Age that our planet has been coming out of for the last 10,000 years or so. One of many Ice Ages that preceded this one, but this one is the one that killed the dinosaurs - who would have already eaten us if they were still around.

Kindly decamp, to Galt's gulch.

This is a Science based forum.

 

[Bob from Florida]

I wouldn't hold out on room temperature superconductors being a practical thing any time soon.

It is the "Holy Grail" to be sure.

 

[BDWoody]

We're not going to change the Earth's climate, no matter what we humans do or how much sacrifice is instilled by the politics of it all. The sooner we face that fact the better we can realistically prepare for the future.

The fact is that our planet is currently experiencing what occurs during the tail end of an Ice Age (that we BTW are still in, as there are still glaciers present on Earth), an Ice Age that our planet has been coming out of for the last 10,000 years or so. One of many Ice Ages that preceded this one, but this one is the one that killed the dinosaurs - who would have already eaten us if they were still around.

If another large meteor hits our planet we go into possibly another cataclysmic Ice Age, and we go the way of the dinosaurs. If our eleven year sunspot cycle goes into a near century of lower sunspot activity and we have another mini Ice Age, like we experienced during the Maunder Minimum, there will be cooling - but by nothing that humans have effected. That scenario is actually forecasted by some scientists but is not a politically popular forecast. Humans are just so overtly bold to believe that they can influence an outcome that is entirely controlled by the power of the Sun and what can happen to a tiny little planet in our universe. Let's not forget that Earth has been here millions of years before humans came to be here on it. We are simply insignificant in the big picture...

Not the right place.

Folks, don't bring this stuff here, and don't feed it when it shows up please.

Back to Audio.

 

[anphex]

Ok, back on track.
Are there some new upcoming amp designs of totally new conceptual technology? Dunno, maybe something with graphene, super conducting material? This would be interesting. Maybe the 120dB SINAD wall could be cracked someday. 144dB is the goal!

 

[Willem]

Not sure there is any point other than price, size, efficiency or power, given that the better amplifiers are already better than human hearing.

 

[ZolaIII]

Ok, back on track.
Are there some new upcoming amp designs of totally new conceptual technology? Dunno, maybe something with graphene, super conducting material? This would be interesting. Maybe the 120dB SINAD wall could be cracked someday. 144dB is the goal!

I am not sure that such aren't already used and I am certain that they will be (for instance IGZO transistor for switching in G-H or GaN in top end switching power supplies). That's becoming available in commercial products (IGZO in displays GaN in mobile phone chargers and high end server grade PSU's) and I am certain it will expand. Meh Graphene is still a paperware and will probably stay that far very very long time (considering how difficult and expensive is to synthesis and how big it needs to be for a Waffer) and even when it's not it will remain very expensive. What I want to see more than anything else is use of Graphite polimer mixtures as separation/isolation of audio components (from IC packaging all the way up to enclosures).