Let's stop calling Class D amplifiers "efficient" when they are not.

[voodooless]

The best I could get out of the Kamado was 280-300.

Try harder I have little issue getting it to 400+ C. Didn’t have much luck with pizza at those temps though. It needs quite a bit of tweaking, but I’ll figure it out eventually.

And sure, for a wok (and pizza), it’s a compromise, but I’m not going to get a specialist tool for everything.

 

[JSmith]

I must say, personally I do not care how much power my gear consumes... what I do care about is whether it runs warm/hot or reasonably cool.

The electricity used by audio gear is so minimal compared to things like A/C, water heaters, refrigerators etc., it's really not worth worrying about from an annual usage perspective. If members are concerned about their overall power usage, best to focus on efficiencies in these types of devices and household insulation etc. rather than audio equipment.

The thread was originally about the efficiency of amps, class D types in particular, in comparison to others... not really about the overall power consumption itself, that wasn't really the point.


JSmith

 

[Brian Hall]

I must say, personally I do not care how much power my gear consumes... what I do care about is whether it runs warm/hot or reasonably cool.

Not generating any extra heat is a priority for me. It hit 105F here in southeast Oklahoma today with 55% humidity. The AC has a hard enough time maintaining 78F inside with those conditions.

 

[antcollinet]

I take no cooking advice from Brits, Dutch, or Germans.

Which is why USAnian food - though tasty - mainly consists of fried-stuff-with-cheese**-and-extra-meat.

**and you have no idea what cheese is either

 

[antcollinet]

We have a kettle -- quite a nice one, given to us by our daughter.

Do you have it on a time switch so you can pre-arrange to get it hot in time for tea next Tuesday?

 

[gwing]

Which is why USAnian food - though tasty - mainly consists of fried-stuff-with-cheese**-and-extra-meat.

**and you have no idea what cheese is either

You forgot the colours, preservatives, bleach and hormones

 

[gwing]

Do you have it on a time switch so you can pre-arrange to get it hot in time for tea next Tuesday?

You forget, real kettles sit on top of the gas or solid fuelled stoves that are doing their stuff baking fresh scones and bread to go with our afternoon tea. None of those imitation plasticky electric things thanks, let alone that stodgy white sludge that passes for bread.

 

[Jim Taylor]

You forget, real kettles sit on top of the gas or solid fuelled stoves that are doing their stuff baking fresh scones and bread to go with our afternoon tea. None of those imitation plasticky electric things thanks, let alone that stodgy white sludge that passes for bread.

True.

Jim

p.s. - no class D efficiency here, it seems!

 

[Tell]

I must say, personally I do not care how much power my gear consumes... what I do care about is whether it runs warm/hot or reasonably cool.

The electricity used by audio gear is so minimal compared to things like A/C, water heaters, refrigerators etc., it's really not worth worrying about from an annual usage perspective. If members are concerned about their overall power usage, best to focus on efficiencies in these types of devices and household insulation etc. rather than audio equipment.

The thread was originally about the efficiency of amps, class D types in particular, in comparison to others... not really about the overall power consumption itself, that wasn't really the point.


JSmith

I don't really care that much about the power consumption of my amplifiers either, especially since I have a RTX3090 computer standing just next to it, but I still find the discussion about the efficiency in power draw to be interesting. And I really don't think there is much to discuss when it comes to heat, size and weight of class D vs AB, you just have to look at them and the answer is there.
And I'm still curious about if it's generally less efficient to use a 500w amplifier than a 50w for everyday usage since it seems that at least some amplifiers are just running at their most efficient when closer to max wattage. But that discussion has been drowned in a kettle discussion. That has been reported though so hopefully it'll be removed soon

 

[SIY]

Try harder I have little issue getting it to 400+ C. Didn’t have much luck with pizza at those temps though. It needs quite a bit of tweaking, but I’ll figure it out eventually.

And sure, for a wok (and pizza), it’s a compromise, but I’m not going to get a specialist tool for everything.

The large burner on my regular gas stove does fine for wok cooking 95% of the time, good enough for when weather doesn't allow me to do it outside on my wok stand. But the flame is absolutely necessary.

My pizza oven is irreplaceable.

 

[Petrushka]

Induction has been awesome for us. We had gas for forever (originally a Viking). I never thought I would give it up. We got an induction hot plate and that was that. It’s like cooking with turbo gas but no flames. Practically magic!

I have a DCS professional gas stove (the previous house owner was a chef) and a 120 v induction hot plate.

The hot plate can boil water faster. Simple physics. Nearly all the energy is transferred to the water.

I’ve used a British 230v kettle. It was not appreciably faster than my 120v version. Both Krupps.

 

[gwing]

I have a DCS professional gas stove (the previous house owner was a chef) and a 120 v induction hot plate.

The hot plate can boil water faster. Simple physics. Nearly all the energy is transferred to the water.

I’ve used a British 230v kettle. It was not appreciably faster than my 120v version. Both Krupps.

There are kettles and then there are kettles. Good ones here in Blighty are 3KW rated, others can be not much more than half of that, how many Watts from the 120V ones?

All of them will be faster than my stovetop kettle of course, but patience is, as I keep reminding myself, a virtue.

 

[madrac]

And that's where the debate is misleading. In other tech areas efficiency is normally evaluated at normal workloads. Do you see car designers publishing fuel consumption when cars are running stationery?

Of course I understand in a home environment amps are often running at low volumes, but if people want to use a 2x 400W class D amp for that then that's their own choice. What pma's measurements show is that such an amp effectively is more efficient for more than 90% of its output range. And that's why the title of this topic could be more nuanced.

Technically & officially, at least in the US and, as I recall, other major markets (Europe, Japan, China), fuel economy (e.g. MPG on the window sticker) is measured with the car stationary. It's placed on a dyno in a lab and a "driver" runs it through a cycle of various speeds/loads/etc. Same thing with an engine oil labeled energy conserving is evaluated in a lab, on an engine - dyno stand and run through a variety of speeds/loads/temps/etc and compared to a baseline oil.

 

[Petrushka]

Technically & officially, at least in the US and, as I recall, other major markets (Europe, Japan, China), fuel economy (e.g. MPG on the window sticker) is measured with the car stationary. It's placed on a dyno in a lab and a "driver" runs it through a cycle of various speeds/loads/etc. Same thing with an engine oil labeled energy conserving is evaluated in a lab, on an engine - dyno stand and run through a variety of speeds/loads/temps/etc and compared to a baseline oil.

This is like the LED bulbs that advertise 17 year lifetimes, and last 2-6 years in actual use. But you wouldn’t have to test home stereos for years. A month would do.

 

[Geert]

Technically & officially, at least in the US and, as I recall, other major markets (Europe, Japan, China), fuel economy (e.g. MPG on the window sticker) is measured with the car stationary. It's placed on a dyno in a lab and a "driver" runs it through a cycle of various speeds/loads/etc. Same thing with an engine oil labeled energy conserving is evaluated in a lab, on an engine - dyno stand and run through a variety of speeds/loads/temps/etc and compared to a baseline oil.

English is not my native language. What I meant with stationary is the engine running at idle speed (which in Dutch is referred to as 'stationair toerental'). A fuel consumption test is performed on a dyno, but it is a dynamic test including accelerations and max speed to 131km/h. The narrative of this thread is, aerodynamic cars are not more efficient because I never drive faster then 30km/h.

 

[J.M. Noble]

English is not my native language. What I meant with stationary is the engine running at idle speed (which in Dutch is referred to as 'stationair toerental'). A fuel consumption test is performed on a dyno, but it is a dynamic test including accelerations and max speed to 131km/h. The narrative of this thread is, aerodynamic cars are not more efficient because I never drive faster then 30km/h.

I don't know how the European authorities do it, but here in the US the tests take into account both the aerodynamics and mass of the vehicle.

How Vehicles Are Tested

Fuel economy is measured under controlled conditions in a laboratory using a standardized test procedure specified by federal law. Manufacturers test their own vehicles—usually pre-production prototypes—and report the results to EPA. EPA reviews the results and confirms about 10-15 percent of...

www.fueleconomy.gov

If I was making car analogies, I'd say the "highway" rating is what everyone uses for amplifiers when they should be looking more closely at how it performs in stop and go traffic.

 

[madrac]

This is like the LED bulbs that advertise 17 year lifetimes, and last 2-6 years in actual use. But you wouldn’t have to test home stereos for years. A month would do.

Explain how vehicle fuel economy testing is like LED bulbs as there is no connection AFAIK.

 

[Blumlein 88]

English is not my native language. What I meant with stationary is the engine running at idle speed (which in Dutch is referred to as 'stationair toerental'). A fuel consumption test is performed on a dyno, but it is a dynamic test including accelerations and max speed to 131km/h. The narrative of this thread is, aerodynamic cars are not more efficient because I never drive faster then 30km/h.

You are exactly right. People are looking at idle consumption and saying they often don't use more than that and the higher efficiency at higher power does not concern them. It is false because at times people do use high power where class AB is inefficient. Also false because several measurements of idle power in class D amps have been provided and conventional AB amps often maybe generally draw more idle current. So class D is slightly more efficient at idle and much more efficient as power use climbs. The thread title is an error.

 

[Petrushka]

Explain how vehicle fuel economy testing is like LED bulbs as there is no connection AFAIK.

Testing fuel economy or light bulb lifespan in a laboratory is useful for comparing products against each other, but it doesn’t tell you what you will get in real life. Although fuel economy testing is much better than it use to be.

But the whole amplifier efficiency thing is misguided if you want to know about environmental impact. You first need a baseline for actual usage in typical homes. Then you can model it for lab testing. I don’t see that anyone has tested real home entertainment systems in real homes, so there is no baseline.

 

[Doodski]

You are exactly right. People are looking at idle consumption and saying they often don't use more than that and the higher efficiency at higher power does not concern them. It is false because at times people do use high power where class AB is inefficient. Also false because several measurements of idle power in class D amps have been provided and conventional AB amps often maybe generally draw more idle current. So class D is slightly more efficient at idle and much more efficient as power use climbs. The thread title is an error.

Man Alive! It would be so effective and cool if we had a power or current and voltage measurement at the time of a ASR test unloaded and loaded.