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

[Doodski]

Actually, it does work.
The test would simply use the same speaker each time for the test.
It gives a baseline of what to expect. With a speaker efficiency of 88dB and higher it's very likely Watts used while idle and at 70dB will be exactly the same or within 1W difference.

The best route is to use a load resister(s) and sine waves. Do it the same way each time.

 

[wwenze]

Actually, no.
If the review included:
1. Watts used while idle (awake waiting for audio).
2. Watts used producing 70dB music.
3. Watts used after idle 10 minutes and energy savings are active (if any).
That would be fantastic.

What I find is amps offer a WIDE variety of energy efficiency while idle even among Class D. In fact, some multi-channel A/B amps offer superior energy characteristics to some multi-channel Class D builds.

The best practice is to turn the amp off when not in use. But even then some designs will use 2x - 8x as much power as others while playing music at the same SPL.

Rewrite 2. as Watts used producing 5W then. Or actually at 70dB it would be more like 0.2W

I decided to arbitrarily use 5W instead of any other arbitrary number since that is the number that is already being arbitrarily used (SINAD @ 5W)

Actually why doesn't Audio Precision put a simulated speaker load inside the box, or is that a paid upgrade
Or even a input power / I / V sensor upgrade but I predict it would cost $30,000

 

[DonH56]

Actually why doesn't Audio Precision put a simulated speaker load inside the box, or is that a paid upgrade
Or even a input power / I / V sensor upgrade but I predict it would cost $30,000

The benchmark speaker load for a long time has been the PowerCube, around $30k last I checked (few years ago). https://www.audiograph.se/stand-alone/ You can (could, I have not looked recently) buy it stand-alone or as part of an AP test system.

 

[mhardy6647]

Hmmm... maybe "we" need a "Green Audio" website.
I am not being 100% facetious.
Maybe 87% facetious -- but not 100%.



Mrs. H & I are listening to a Rumours via a single-ended direct heated triode amplifier on DIY loudspeakers with Altec drivers and 100-plus dB sensitivity (1 watt @ 1 meter) as I type this.



ca. 6 kW worth of photovoltaics on the roof and a high-efficiency inverter Mitsubishi heat pump keeping us comfortable, so I don't feel too guilty...

 

[Doodski]

Hmmm... maybe "we" need a "Green Audio" website.
I am not being 100% facetious.
Maybe 87% facetious -- but not 100%.



Listening to a Rumours via a single-ended direct heated triode amplifier on DIY loudspeakers with Altec drivers and 100-plus dB sensitivity (1 watt @ 1 meter) as I type this.

I think it's prime time for 1 or all of these measures like efficiency, Watts, power factor and maybe mains volts metering of all tested gear. People are energy efficiency conscious these days.

 

[wwenze]

Hmmm... maybe "we" need a "Green Audio" website.

SilentPCReview died, so we couldn't even sustain a Green Computer website

 

[Doodski]

SilentPCReview died, so we couldn't even sustain a Green Computer website

Maybe but ASR can add the power, power factor and efficiency figures to it's measurement repertoire. I suspect that will draw in a lot of interested people that otherwise might not come here to ASR.

 

[mhardy6647]

Maybe but ASR can add the power, power factor and efficiency figures to it's measurement repertoire. I suspect that will draw in a lot of interested people that otherwise might not come here to ASR.

That would be (ahem, it could be) a nice "Trojan horse" strategy to lure... umm, I mean attract, non-objectivists (or maybe agnostic objectivists is a less pejorative way to think of such folks) to the fold. I'm not being entirely facetious.
Heck, the tear-downs here are what hooked me. I was deeply skeptical of all y'all, but the liveliness of this forum beats pretty much all of the classic hifi forums at this point.
And I still listen to vinyl and tape via tubes and horns (keepin' PVC and Mylar out of the landfills, you know?), so there's that...


In all seriousness, I don't think "tech" manifests such good optics when it comes to environmental conservatism. Anything we could do to improve that is probably A Good Thing.

________________
* As Martha Stewart and/or Jerry Pournelle are/were wont to say.

 

[Head_Unit]

Here's a development for better efficiency. For small amplifiers but I'd assume scalable?
https://audioxpress.com/news/new-fr...nology-maximizes-battery-life-in-tws-earbuds/

 

[pseudoid]

Exercise

In all seriousness, I don't think "tech" manifests such good optics when it comes to environmental conservatism. Anything we could do to improve that is probably A Good Thing.

What's next?
Bumper stickers saying "ASR supports the ethical treatment of electrons!"

 

[tomtoo]

Oh man the last thing i like to do is to discuss how enviromentel friendly a 5W tube amp is........

 

[mhardy6647]

Oh man the last thing i like to do is to discuss how enviromentel friendly a 5W tube amp is........

(with the best Barney Fife vocal fry I can muster)
"That's why mine is three point five watts..."

 

[tomtoo]

(with the best Barney Fife vocal fry I can muster)
"That's why mine is three point five watts..."

View attachment 388050

 

[atmasphere]

Oh man the last thing i like to do is to discuss how enviromentel friendly a 5W tube amp is........

We make a stereo 5W/channel PP tube amp... It draws far more power then our class D does (which draws about 50mA at idle from the AC line). There's no way the tube amp is more efficient at any power level it can make compared to the class D. If a class D amp is only 70% efficient at some mid level power that's still more efficient than a straight class AB amp of the same power. We're having this discussion why??

 

[Sylvanus]

42 pages! This thread is just getting started.

 

[Petrushka]

We make a stereo 5W/channel PP tube amp... It draws far more power then our class D does (which draws about 50mA at idle from the AC line). There's no way the tube amp is more efficient at any power level it can make compared to the class D. If a class D amp is only 70% efficient at some mid level power that's still more efficient that a straight class AB amp of the same power. We're having this discussion why??

I mentioned a couple dozen pages ago that efficiency is an unimportant metric. If you are interested in power usage, meter it for a week or a month in normal use.

Edit: even more pertinent, regardless of efficiency, 100 percent of an amplifier’s output is converted to heat. The only interesting number is power consumption over time.

 

[tomtoo]

We make a stereo 5W/channel PP tube amp... It draws far more power then our class D does (which draws about 50mA at idle from the AC line). There's no way the tube amp is more efficient at any power level it can make compared to the class D. If a class D amp is only 70% efficient at some mid level power that's still more efficient that a straight class AB amp of the same power. We're having this discussion why??

I talk about 5w tube amps. Who cares about there efficience?? This are niche products. Buy a tesla plaid and we talk about 600kw++. And then you realy like to talk about a 5w tube amp? Thats more holy than the pope. Not with me. I not talk about if a 5w tube or a 5w class d is more efficient. Couse this tube amps are not often used its not realy interesting. If someone loves them let they have there fun.

 

[Lux_ury]

This is for restorer john!
Conflicting, it is its the largest Heatsink I own and the smallest also.

 

[atmasphere]

I talk about 5w tube amps. Who cares about there efficience?? This are niche products. Buy a tesla plaid and we talk about 600kw++. And then you realy like to talk about a 5w tube amp? Thats more holy than the pope. Not with me. I not talk about if a 5w tube or a 5w class d is more efficient. Couse this tube amps are not often used its not realy interesting. If someone loves them let they have there fun.

I think you might not have read my post correctly.

 

[wwenze]

We're having this discussion because somebody observed that a 500W class D amp idles at a higher wattage than a 10W class AB and decided to start a thread about it

I'm scared to even say 40W class AB because I have a 40W class AB integrated and it idles at 25W