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

Class D is most efficient because after 5 mins you Turn them off and walk away ..!

:)
 
I see a point in using class AB for headphone amps, primarily due to a lack of class D headphone amp products.
 
So why not high bias class A for everything?
This is a high fidelity amplifier class. Class A amplifier's output transistors run at full power whether there's an input signal or not. When there's no signal, the transistors' power transforms into heat. When there is a signal, the power goes out the speaker terminals.

Also, each Class A output transistor amplifies both the negative voltage and the positive voltage parts of the signal's AC waveform, increasing the workload and raising more heat. Class A amps function at a 25% efficiency level and the remaining 75% of their power is turned into heat.

There are no turn-on, turn-off, warming, or cooling cycles that would affect the signal flow. In this class, you get distortion-free performance. Besides there is no switching going on, meaning there is no induced high-frequency interference. Pure Class A amplifiers are rare and expensive.
 
I not talk about if a 5w tube or a 5w class d is more efficient.
The difference is not going to stop global warming, no. :D
However in battery powered application of many sorts, designers and indirectly users DO care about the efficiency.
 
Err, academic response not to the question.

Class A operation has superior sonics to the others, for headphones they make the best choice , class D is not for sonics but for high power @ reduced cost, size , etc ..

Same for class H , AB , B , these are all compromises to sonics based-on application where high biased class A is prohibitive ..

Class A is not best for high powered application , well not all ..


Regards
 
Class A operation has superior sonics to the others

Class of operation has nothing to do with "sonics". Class A can be made to perform well or not, and the same for class A/B, G, H and D. If the designer is competent, understands the advantages and disadvantages, there is no problem. If the designer is incompetent or has willfully non-neutral leanings, then there is a problem .... and it will exist with each and every class of operation.
Many of the choices for amplifier designs today have to do with efficiency of manufacture as well as other considerations. Assembly line efficiency, educational level of the employees, embedded costs and long-term availability of parts are very important factors for companies producing all sorts of amplifiers. Business comes first and foremost, and many (if not all) of these companies have different priorities than we do.

Jim
 
Do i have to say it, we are talking absolutes not strawman every chink in armor content...

Specifically sonics.

:rolleyes:
 
Class D is most efficient because after 5 mins you Turn them off and walk away ..!

:)
It’s Audiophilia we work with sights ...
Do i have to say it, we are talking absolutes not strawman every chink in armor content...

Specifically sonics.

:rolleyes:

You are not making sense. Your profile doesn't indicate your country of origin, but if I had to guess, I'd guess that English is not your native language. In order to translate more accurately, and possibly maintain a grasp of idiom, please try this translation app:


Jim
 
The difference is not going to stop global warming, no. :D
However in battery powered application of many sorts, designers and indirectly users DO care about the efficiency.

Sure thats why you wont see tubes in this applications. It would be completly stupid. So still no need to talk about the efficience of 5w tube amps.You wont see tubes in BT inears. ;)
 
Sure thats why you wont see tubes in this applications. It would be completly stupid. So still no need to talk about the efficience of 5w tube amps.You wont see tubes in BT inears. ;)

Now you've done it. I'm sure someone will try it.

1724544096944.png
 
Speaking of battery-powered, I wonder how they pack 6 hours into each earbud

hEbcDtw.jpeg


(21 hour total, 6 hour earbud 15 hour case)
 
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