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

[Andysu]

LEDs ruin the sound, anyways.

 

[AdamG]

Idle is when the device is fully on and ready to play.

Standby is when you turn the device off with the remote or it turns off automatically after a while. Usually, a red LED Turns on to signify this.

Off is when you flip the power switch on the back of the unit, or plug out the mains cable entirely.

Yeah. That ^

 

[Chester]

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

But what do you really think

 

[radix]

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

I'm pissed that the EMF property of AMPS keeps pushing my electrons OUT of the amp. How am I supposed to burn them in if they are always leaving? how are they supposed to get good at amplifying?

 

[Deleted member 48726]

Idle is when the device is fully on and ready to play.

Standby is when you turn the device off with the remote or it turns off automatically after a while. Usually, a red LED Turns on to signify this.

Off is when you flip the power switch on the back of the unit, or plug out the mains cable entirely.

I don't get it. Can you maybe explain it using a car analogy?

 

[anome]

Much prefer the good eats in my favourite restaurant analogy.

 

[staticV3]

I don't get it. Can you maybe explain it using a car analogy?

Idle=idle
Standby=you're at a traffic light and start/stop has stopped your engine
Off=all systems are off and you've taken out the key

 

[Deleted member 48726]

Idle=idle
Standby=you're at a traffic light and start/stop has stopped your engine
Off=all systems are off and you've taken out the key

Now do a plane!

 

[staticV3]

Now do a plane!

Now you've got me sweating. Do planes have start/stop?

 

[anome]

I'm absolutely gobsmacked at the outrageously contentious assertion of the OP, if I wasn't such a lazy sod I would connect the meter to measure. But, I think I will just let the music keep playing and point at post as that is what is currently driving my speakers. Gotta say though, I do not think of the power consumption of that unit whether in standby, idle or full-tilt, it just don't matter.

 

[IAtaman]

Now you've got me sweating. Do planes have start/stop?

They have internal combustion engines at the tail called auxiallary engine that powers the hydrolics, aircon and other stuff when the turbofans are not running. That is idling isn't it.

Now I think about it, a modern internal combustion engine with ca 40% thermal efficiency is probably more efficient than a lot of class A amps isn't it.

 

[IAtaman]

I don't think there is any point in the % power graph where AB does better than D including 0%, is there? John would know better frankly, which makes me think that this thread is some sort of a social experiement to see how people will react to an assertion that Class D is bad?

 

[AdamG]

Now do a plane!

Idle = Gliding followed by Crashing.
Standby = The position you take just before impact with ground.
Off = Status of life signs immediately following impact. Hard deceleration, see death, possibly afterlife.

 

[anome]

Idle = Gliding followed by Crashing.

Unless you're in a Gimli Glider

 

[radix]

Now do a plane!

A 757-300 fuel use:

- Cruise altitude, 0.78 mach = 2630 kg (5800 lbs) per hour
- Idle on tarmac = about 300 kg (660 lbs) per hour [I could not find exact numbers for this, it's a bit of an approximation]
- Off = 0 (assuming no leaks)

 

[simbloke]

I really wanted to know my answer to John's post. But my power meter has my home server plugged in too it, so I'm not touching it! My unscientific answer is, I'm just not that bothered.

 

[RickS]

Idle is when the device is fully on and ready to play.

…and no input signal is present.

Standby is when you turn the device off with the remote or it turns off automatically after a while. Usually, a red LED Turns on to signify this.

Close as this is how you might get there, but more specifically for most newer Class D amps, what is happening is the power supply is usually in a lower power state and waiting on event (like a trigger input) to make full power available.

Off is when you flip the power switch on the back of the unit, or plug out the mains cable entirely.

Obvious, but not sure why it matter in this thread’s context.

 

[HoweSound]

I don't think there is any point in the % power graph where AB does better than D including 0%, is there? John would know better frankly, which makes me think that this thread is some sort of a social experiment to see how people will react to an assertion that Class D is bad?

John appears to be casting himself in the role of Jason and the dragons' teeth - he throws out the comment, then stands back to watch...

Jason​

Similarly, Jason was challenged by King Aeëtes of Colchis to sow dragon's teeth from Athena in order to obtain the Golden Fleece. Medea, Aeëtes' daughter, advised Jason to throw a stone between the warriors that sprang from the earth. The warriors started fighting and killing each other, leaving no survivor but Jason.

(wikipedia)

 

[Descartes]

Now here is what John would call a real man's amp. Rated 125 W into 8 ohms (and weighs 101 lbs). Idle power consumption 230 W per channel (it is a mono amp).

View attachment 316563

Cost over $20,000!

 

[MAB]

Now here is what John would call a real man's amp. Rated 125 W into 8 ohms (and weighs 101 lbs). Idle power consumption 230 W per channel (it is a mono amp).

View attachment 316563

He probably has three of them lying around.