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

[MakeMineVinyl]

This is the point. and this is why it is not regardless of power output rating.

Well, measure the temperature of the output inductors then on examples you have and provide a nice spreadsheet. Just don't try to use the finger you burned.

 

[Bob from Florida]

I also disagree that in the past washing machines and the like were more reliable. I would say on the contrary.
do, and they are not always the ones you think of first.

I think you are confusing efficiency and features with reliability.

How to Make Your Washer and Dryer Last Longer

Consumer Reports offers advice on how to make your washer and dryer last at least a decade.

www.consumerreports.org

As indicated above the average life for washers and dryers nowadays is around 10 years. We purchased the cheapest Kenmore set back in 1984 for $500. They were still working 16 years later when we upgraded. The upgraded washer lasted 2 years 1 month - just outside warranty - before failing in such a way that it was non-economical to repair.

If you like government regulations, one that might make sense is a repairability requirement for durable goods. Twenty years before "end of life" would shift the industry away from throwaway to service. By service I mean DIY or a repair service.

 

[antennaguru]

I have.
But you seem to have it to....
If you drive a car with 800Hp and one with 80Hp and you drive at normal hing way speed for an hour i’m very sure the one with the bigger motor will uses more Flue...
So this is not in any way shape or form telling if they have vastly different power ratings.

It is the power used from the AC outlet that determines consumption, not the power rating. That is where I ACTUALLY measured kWh for the whole system including the Nakamichi preamp/tuner used to drive all four (4) power amplifiers.

BTW, the IcePower 125ASX2 power amplifier module is only rated at 65 Watts Output per channel into 8 ohms. Don't be confused by the ambitious 125 Watt Output per channel rating that only pertains to 4 ohms. The speakers I used for the measurements that I ACTUALLY made are nominal 8 ohms impedance. The two Class AB power amplifiers are rated at 70 Watts Output per channel into 8 ohms, so they have the same output rating as the Class D power amplifier. They both only used a few pennies more power per month than the Class D power amplifier.

The pure Class A power amplifier is rated lower in power output but was played every bit as loud as the other amplifiers, over the same speakers. It is a constant bias pure Class A power amplifier whose power usage does not change one bit between idle and full volume, and that's just the way pure Class A works. Yes, compared to the other amplifiers, all playing over the same relatively inefficient speakers at the same moderately high volume level (loud) the Class A power amplifier does use more power - to the tune of the cost of one cup of Starbucks coffee per month. That "inefficiency" goes into room heating - meaning that you can turn down your space heater a little bit and save some energy there.

This whole green thing is so over-hyped! Next you'll tell me I didn't ski on a glacier two years ago (which I did in early October at the end of the summer in Austria), or that glaciers on Earth don't mean we're still in an Ice Age. Let's stick to the facts/measurements and not the theories and politics.

 

[NiagaraPete]

Just an observation. Genelec speakers use class D up to the last couple models then they change to AB? Does that say something?

 

[Holmz]

Just an observation. Genelec speakers use class D up to the last couple models then they change to AB? Does that say something?

I dunno… What do we want it to say?

 

[MakeMineVinyl]

Just an observation. Genelec speakers use class D up to the last couple models then they change to AB? Does that say something?

It says that the lack of heat in an enclosed speaker cabinet is something to strive for.

 

[garbulky]

I think they both have their place. I use high bias class A/B amps (the XPA-1 gen 2 which can do up to 60 watts in class A). But I also fell in love with the Emotiva PA-1's which have a much lower output class D module and is a fraction of the size. Having said that, I trust that big torroid is going to last longer than the tiny switcher in the PA-1. In terms of measurements, class D amps can produce very good low distortion measurements. However class AB amps (with larger size PS) can produce higher power over substantially longer periods of time and are more tolerant of heat dissipation in general. Is that because its AB? Probably not, I'm guessing cost and space savings in class D have amps that can't maintain powerful output for long periods of time.

 

[jasonhanjk]

You misread me. I said that both the class a b amplifiers and the class D amplifiers are the same power. In any event that doesn't matter just please do the experiment touch your finger to the output inductor of a hypixel amp of any power in the 100-W range or over.

Output inductor hot are due to:
Higher supply voltage
Lower inductance value of inductor
Higher capacitance value, capacitor after the inductor
Higher internal resistance of the inductor

An engineer will know what to do to reduce the heat dissipate by the inductor.

 

[Holmz]

I think they both have their place. I use high bias class A/B amps (the XPA-1 gen 2 which can do up to 60 watts in class A). …

Why not just get a Class-A then?

And put a D, B or AB on the woofer section?

 

[Willem]

As indicated above the average life for washers and dryers nowadays is around 10 years. We purchased the cheapest Kenmore set back in 1984 for $500. They were still working 16 years later when we upgraded. The upgraded washer lasted 2 years 1 month - just outside warranty - before failing in such a way that it was non-economical to repair.

If you like government regulations, one that might make sense is a repairability requirement for durable goods. Twenty years before "end of life" would shift the industry away from throwaway to service. By service I mean DIY or a repair service.

Our Bosch and Miele washing machines, dishwashers and driers have all lasted at least twenty years, and when requiered could easily and economically be repaired. The biggest problem with older appliances was the mechanical program switch.
The EU has indeed recently introduced repairability regulation. However, our modern ones are considerably more frugal with electricity (the Miele drier uses heat pump technology), and are vastly quieter.

 

[Willem]

This whole green thing is so over-hyped! Next you'll tell me I didn't ski on a glacier two years ago (which I did in early October at the end of the summer in Austria), or that glaciers on Earth don't mean we're still in an Ice Age. Let's stick to the facts/measurements and not the theories and politics.

Global warming itself is a scientific fact - the politics is about distributing the burden of the required transition.

 

[Holmz]

Global warming itself is a scientific fact - the politics is about distributing the burden of the required transition.

That may be true, but I am not throwing away working 20-40 year old gear onto a landfill, to get some Class-D gear flown on a plane half way across the world… unless it is at least Purifi or Hypex gear.

One would likely be better off riding a bicycle, or taking a bus, once a week to make up for power usage from a stereo.

 

[Willem]

Oh, so taxing extra to introduce a penalty for not complying with green initiatives is a good solution? How about introducing an actual incentive for lower utilization? Also, what are they doing with that extra taxation they collect?

As I said, this is textbook market economics and is precisely an incentive. Raising the tax on natural gas and lowering it on electricity uses the same market economy mechanism. It is combined with building codes that demand high levels of insulation for new homes, ban natural gas heating for all new homes (i.e. mandate heat pumps), and introduce subsidies for the insulation of existing homes and replacing gas boilers with heat pumps. Of course, if you do not believe the climate science, this is all a waste of money, but if you do, it is money well spent.
And to return to class D amplifiers, the EU now has mandatory levels of energy consumption for many appliances. beyond that, there are standards to inform consumers about the energy consumption of their appliances, to create a more transparent market. That again is textbook economics. Thi shas not yet happened for audio gear (it has for televisions), I suppose because that is only a small market.

 

[Willem]

That may be true, but I am not throwing away working 20-40 year old gear onto a landfill, to get some Class-D gear flown on a plane half way across the world… unless it is at least Purifi or Hypex gear.

One would likely be better off riding a bicycle, or taking a bus, once a week to make up for power usage from a stereo.

I agree, and I did not throw away my power hungry Quad 606-2. However, the question in this thread was about new designs for amplifers. And yes, I use my bicycle to get around town.

 

[Lambda]

to get some Class-D gear flown on a plane half way across the world… unless it is at least Purifi or Hypex gear.

Keep in mind the price you pay must include all the energy for transportation and manufacturing.
If you only listen to 5W on average it might not be a big difference.
But getting rid of that old refrigerator or light bulb pays off/back fast.

 

[garbulky]

Why not just get a Class-A then?

And put a D, B or AB on the woofer section?

60 watts high bias satisfies what I want from Class A power for the entire speaker. I don't want to mix amps. The reason I bought the XPA-1 gen 2 is that it doesn't max out at 60 watts. After 60watts of power is exceeded, the amp switches over to B like an AB amp and is able to push out up to 1000 watts of power at 4 ohms. It also has a switch that brings the bias down to a more regular amp and then the heat and power consumption is much less. So I get a choice.

 

[Bob from Florida]

Global warming itself is a scientific fact - the politics is about distributing the burden of the required transition.

Scientific "facts" change as evidence and understanding evolves. Climate change has occurred throughout the history of this planet. The real question is how much impact do humans have and what can be done by humans to influence climate change to our benefit. Like all life on the planet, we will have to adapt to continue existing.

 

[Willem]

The real question is how much impact do humans have and what can be done by humans to influence climate change to our benefit.

Sure, part of my historical research is on past climate change from natural causes. However, what we are experiencing now is man made, and with enough impact to upset our life style. 50% of my country is already below sea level (I am lucky as my house is a few feet above) and if sea level will indeed rise by 1-2 meters this century, we may be reaching the limit of what our famous water management technology can cope with, at least in parts such as near Amsterdam, Rotterdam and The Hague, our three largest cities. So what can we do to avert this danger?

 

[ZolaIII]

Scientific "facts" change as evidence and understanding evolves. Climate change has occurred throughout the history of this planet. The real question is how much impact do humans have and what can be done by humans to influence climate change to our benefit. Like all life on the planet, we will have to adapt to continue existing.

Well some life will adapt (some even won't be effected at all) when there is no ozone shilld but those certainly aren't humans.

 

[Bob from Florida]

Sure, part of my historical research is on past climate change from natural causes. However, what we are experiencing now is man made, and with enough impact to upset our life style. 50% of my country is already below sea level (I am lucky as my house is a few feet above) and if sea level will indeed rise by 1-2 meters this century, we may be reaching the limit of what our famous water management technology can cope with, at least in parts such as near Amsterdam, Rotterdam and The Hague, our three largest cities. So what can we do to avert this danger?

Move to higher ground. If sea levels really rise by those amounts, likely nothing can be done.