Audiom | 100-W audio amp is 20 times more efficient than Class D chips

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kavermei

kavermei

Member
Joined 2005
On a more serious note, I've no doubt the device will be more power-efficient than the current generation. Exactly how much is very difficult to determine, even from the data sheets, since there are so many parameters the manufacturer can influence to make it look good...
 
wakibaki

wakibaki

Banned
Joined 2008
If it's 20 times more efficient then the systems it's being compared to can be 5% efficient at best.

I think you have to pick your ground carefully if you want to argue about the figures, because they're talking about 'normal listening levels' and this is without reference to any speaker efficiency. Who knows what this really means? Why would it not be possible to run a class D amplifier in a regime that put the required output levels in the most efficient part of it's range? Sensible dimensioning. You can easy pick a point where an amp of a particular class performs bad.

I can see somebody claiming something that is 20 times less inefficient (or one twentieth as inefficient, as in an improvement from 70% to 98.5%) is 20 times more efficient, people use language very loosely sometimes. Me too.

Anyway they've got a chip and you don't usually get that far on a a fantasy so I'm curious to know what it really is that they've got. I've been doing some experimental toaster oven SMT boards, I might try to get hold of one of these...

w
 
Z

Zola

Member
Joined 2009
20 TIMES NOTHING = NOTHING
I'm working for more than 20 years in electronics design. I've ordered hundreeds and hundreeds samples, not a single "normal" firm asked me money for them! This one (Audim) asks money for them! In the site they wrote: "Samples are available now, priced from $8 each in 1000+ quantities" (Audium Semiconductor). Imagine, they want to sell their samples in quantities of 1000 at a price of $8. Who is the freak that will order 1000 samples of a product without any datasheet? More than that, it is an UK based firm and they are asking to pay them in dollars, but they do not mention what dollars! Australian? Canadian? Hong Kong? Singapore? US? Or maybe fraudulent dollars!
 
Eva

Eva

Member
Joined 2003
The efficiency plot suggests 10W peak power rather than 100W because it goes up to 5W rms only. They probably put an extra zero on the text by mistake.

The 20:1 efficiency improvement is at 20mW rms. The same plot shows worse efficiency than traditional class D above 1W.

Really nice for portable MP4 players and the like...
 
Z

Zola

Member
Joined 2009
Ecological Monster!

Ask yourself, what use you would have of an amplifier who, at full power, will “eat” your batteries in several minutes! And to be more irronical it is proclaimed as an ecological solution (with a full bag of chemical poisons from its used batteries)!
 
Eva

Eva

Member
Joined 2003
Zola said:
Ask yourself, what use you would have of an amplifier who, at full power, will “eat” your batteries in several minutes! And to be more irronical it is proclaimed as an ecological solution (with a full bag of chemical poisons from its used batteries)!
Click to expand...

Amplifiers can only work at full power on a test bench. Real world audio signals are typically below 1/8 of full power (averaged over time). Speech signals may be below 1/25 of full power.

Wasting very little power during the quietest parts of the signal allows to use much higher peak power and thus to get louder output with the same battery power. It makes a lot of sense for me. In most class D amplifiers, the efficiency figures at low output powers are ruined by too high idle consumption, similar to class AB or worse. This is really a problem with batteries.

A perfect amplifier would be able to transfer battery power directly to the speaker (and back to the battery as required) without any loss (losses would only happen in the speaker).
 
Z

Zola

Member
Joined 2009
Formula 1 running at 20 Km/h

Absolutely true, my dear Eva! But as you said, real audio signals are typically below 1/8 of full power or, I say, in worst case below 1/100! So, if we would like to listen at 20 mW levels (as the manufacturer wants to use its 100W power amplifier) common sense is to build at most a 2W amplifier. At the present market of few watts D class integrated amplifiers we have a reasonable quantity of items with idle consumption of less than 100mW! This inputs that their main quantitative attribute non characteristical to any science (referring to the silly 20X) falls in water! Building a 100W amplifier and use it at 20mW is similar to buy a formula 1 and drive it at 20 Km/h! Who cares about the formula 1 fuel consumption at 20 Km/h?
Last but not least, why do you (and many others) constantly keep comparing this amplifier with D class amplifiers? According to the poor explanation they gave, it is absolutely not a D class amplifier! If you want to classify it, it is more likely a modified BASH amplifier. And BASH has much less problems with idle consumption!
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Erare humaum est! Every one knows this one! But just few knows that this proverb does not end here. The continuation is: Persevere erare, diabolicum!
 
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