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

[pma]

Tell me, how much power do your class D amplifiers consume, just idling along, doing nothing, or even playing slightly loudly? Measure it and be shocked. Report back here with your results.

Class D "efficiency" is utter and complete bullsh#t.

My stereo class AB amp with MOSFET output stage and error correction eats 15W at very low volume and up to 20W at my normal listening level.

 

[voodooless]

Class D "efficiency" is utter and complete bullsh#t.

It's efficient when you actually need it, I don't see a problem.

 

[Matias]

Class D "efficiency" is utter and complete bullsh#t.

Having another bad day again, huh?

Here are some Japanese amps and their idle power drawn (source: Stereoplay magazine - Germany).
Yamaha M-5000 - 56W
Yamaha A-S3200 - 50W
Yamaha A-S1200 - 50W
Accuphase E 460 - 82W
Luxman L 509u - 77W
Luxman L-505uXII - 93W
Luxman SQ-N150 - 82W
Luxman L-550AX - 168W
Luxman MQ-300 - 154W
Luxman L-595ASE - 160W

Not to mention other brands from other countries.
Octave Audio Jubilee 300B - 331W
T+A M 40 HV Anniversary Edition - 220W
T+A PA 3100 HV + PS 3000 HV - 198W
Dan D'Agostino Momentum Integrated - 210W
Dan D'Agostino Progression Integrated Stream - 120W
Pass INT-250 - 240W
Rotel Michi M8 Mono - 93W
Krell Evolution 402e - 342W

Let's not even compare efficiencies when musical power is drawn!

It was a long time that we didn't get "Class D is bad" thread. I was somehow missing it. Or not.
An Arthur 4215/E2 eats less than 0.5 W in standby, 12 W when idling. In idling 9 W are eaten by the power supply, not related to class D, and 3 W by the 2 1ET400A modules that happen to be class D. In my book it's quite efficient.

+1

 

[Barrelhouse Solly]

Sounds like the lesson is to turn off the amp when you're not using it.

 

[maverickronin]

My Buckeye NC252MP idles at a whole 15W.

I cut the power to it completely overnight.

 

[NTK]

But we all know precision instruments are designed to work best after they have reached thermal equilibrium

 

[Talisman]

My class D toys (V3, bt20a pro, breeze dual 3116) consume zero consumption when not in use, because they are deactivated by a smart socket (it is also the safest way to avoid risks with cheap power supplies). I can't do the same with my class ab (Cambridge audio cxa61 and onkyo 9010) because they have to be turned on by the button even after they are powered.
In my case therefore the gap is huge due to the way of use.

 

[maverickronin]

Other stuff I should have measured before.

The Crown XLS 2502 I use for my subs idles at 30W.

My DSP crossover, a BSS-BLU-160 draws 26W

Overall, I'd say the Hypex is doing ok at 15W

 

[computer-audiophile]

... are deactivated by a smart socket (it is also the safest way to avoid risks with cheap power supplies). ...

There's a lot of reasons that smart plugs can sometimes melt or explode when they are used with high amperage or high wattage devices in your home.

 

[Blumlein 88]

My old Wyred4Sound ST500 amps draw 27 watts when I just checked at idle. Spec is 28 watts. Basically a 250 wpc 8 ohms amp. About 450 wpc into 4 ohms. Plays Soundlabs with ease. If I let it idle all the time rather than be in standby (consuming 1/2 watt) it would cost me about $30 a year in electricity.

I could pull out an old Yamaha M65 and check it. It supposedly does class A to 20 watts while being basically a 200 wpc 8 ohm amp. Pretty sure it will pull this much or more. I owned a Mark Levinson ML9 100 wpc 8 ohm amp once. Don't have it any more, but spec for it was 100 watts at idle. Ayre Acoustics VX8 a current 100 wpc old school amp is said to draw 60 watts.

So maybe we can put to rest this ridiculous idea a class D amp is some kind of inefficient amp vs most regular AB amps.

 

[fpitas]

Have we considered that all that switching wears out the electrons?

 

[Music1969]

So maybe we can put to rest this ridiculous idea a class D amp is some kind of inefficient amp vs most regular AB amps.

Well maybe @restorer-john can back his claims with some objective data

The anis is on him to back this up

 

[Blumlein 88]

Have we considered that all that switching wears out the electrons?

In competent switching designs that is part of the beauty of it. You switch the electrons back and forth rapidly. Then only peel off the tired ones which can be manipulated in a very supple manner resulting in smooth easy sound.

 

[IPunchCholla]

While the efficiency of a Class D is going to be about the same as a Class A/B for the most common use cases, the increased efficiency of Class D at higher power draws allows designers to minimize the amount of heat dissipation required for “max use case” scenarios. This allows for much less material required which leads to smaller enclosures, which leads to cost savings…

To put it simply, pure class As have to have massive heat sinks because they are always running at their max. ABs can have smaller heat sinks because they are running more efficiently at max, and Ds can have much smaller heat sinks because they yet more efficient at max. This leads not to efficiencies at normal listening volumes, but efficiencies almost across the entire design.

 

[Digby]

It's ironic when old guys want amps they can no longer lift.

/Trollin, oh yeah

Well, duh, why do you think amps are spread all over the floor these days?

 

[gnarly]

QSC CXDQ 4.5 network amp. 4 channels x 1150W continuous per ch
<100W at idle
PowerSave mode turns on when input signal drops below user settable threshold and time duration

 

[Philbo King]

Have we considered that all that switching wears out the electrons?

Sort of frustrating that the power company gets rich by selling us the same electrons over and over...

 

[Matias]

What the heck I went ahead and measured my amp: 1.0W in standby and 41W idle. That is with 2 x power supplies, 2 x SS2490 discrete opamps, and 2 x NCx500 modules. This amp puts up to 700W per channel into 4/2 ohms. Never runs hot, barely warm.

Now find me a class AB power amp of similar power that draws less power when idling. I will wait.

 

[Guddu]

Adding what I've seen with TPA3255:
Aiyima A07/Pro consumes about 6 W when powered ON but nothing playing, it then remains around 6-7 W to my normal listening volume sitting 3-4 meters away.
It goes around 10-12 W when I try to push it a bit.
I know that I haven't included SPL here, but to me, TPA3255 is efficient enough while in operation at least.

 

[MAB]

30 watts per channel,I changed my mind,don't want one
(I have big room to fill )

Bigger than 86m³? Cuz it does that very well

Perhaps get more efficient speakers... or are efficient speakers no longer... efficient???