Class/type of amp ?

"Arfa Daily" wrote in news:C3Z2l.7364$ snipped-for-privacy@newsfe09.ams:

If one wants to understand a concept, one makes sure that they understand how the words are being used.

Understanding what others mean when they use a certain word is important to communications.

In many technical fields, 'common words' have 'uncommon definitions'. This leads to a LOT of misunderstandings and has high costs, but it is often useful and necessary.

A 'careful communicator' will try to find out what others mean when they use specific words and tailor their communications to use the language of the listener. Doing otherwise is as counter productive as walking into a room full of people that only speak Etruscan and giving a lecture in Greek.

Arguing about what a word 'really means' is a waste of time and energy.

If one wants to communicate with others, one uses words that others understand in the way that they understand them.

You COULD call them AB + G or AB + H but since it's a bit of a mouthful most people don't. Rail switching or modulating is a bit technical for the average buyer.

Graham

So what exactly are you saying here ? That it's right to use the word "digital" in it's modern context, which all service engineers world-wide would understand, or not ? Each time I read thru' what you've said, I arrive at an opposite conclusion ! :-)

I *try* to be a careful communicator always, allowing for the fact that people who are not native English speakers, may well be reading, and also that many Americans will be reading, who tend to use the language in a much more 'literal' way than those of us in the UK. That difference, and the difference in sense of humour, can easily lead to conflict, so I try to take both of those factors into account when I do post.

Maybe I don't get it right all the time, but at least I do try ..

Arfa (dah-di-dah)

Arfa

The word "class" has several meanings. One of them has an implication that is different from "type". Class A -- conduction through the full cycle -- is not called A by accident.

But that isn't the point. If company A used the same circuit as company B, it would be foolish for them to use the same designation. That was the point, not whether "class" G and "class" H are the same or different.

That's a very restricted use applying only to A, B and C.

Do you mean 'topology' rather than circuit ?

But they DO ! Very many brands of Class G and H amps exist ! G or H describes the method used to reduce dissipation in the output stage.

I don't even begin to understand that statement, sorry.

Did you read the wikipedia link btw ?

Graham

arrive

I agree. This is a technical issue, not one of getting along with people from a different society.

'K?

AB.

That's true, but if the average buyer doesn't have at least some minimal understanding of how the circuit works, then the letter pretty much means nothing -- other than as a way to distinguish to product, or (possibly) impress him.

"Rail switching" is a good term. Here's a simple explanation for the technically uninformed:

"A high-power amplifier requires a high voltage on its output stage. But the higher the voltage, the hotter the amplifier runs. Because the highest output power is rarely needed for more than a few seconds, this amplifier uses a switched power supply, "cranking up" the voltage only when it's needed. This lets the amplifier produce a lot of power without a lot of expensive output transistors or huge heat sinks."

That's pretty good for a first draft.

Yes.

I browsed it. I agree that there is a mean "Class D amplifiers can be controlled by either analog or digital circuits. The digital control introduces additional distortion called quantization error caused by its conversion of the input signal to a digital value."

and

"The letter D used to designate this amplifier class is simply the next letter after C, and does not stand for digital. Class D and Class E amplifiers are sometimes mistakenly described as "digital" because the output waveform superficially resembles a pulse-train of digital symbols, but a Class D amplifier merely converts an input waveform into a continuously pulse-width modulated (square wave) analog signal. (A digital waveform would be pulse-code modulated.)"

Except for the last sentence, this is a correct statement.

Well, I've read all you have to say, and I take on board your points, but I find some of your thinking, as always in these discussions which wake up the bee that lives in your arse, convoluted at best. You seem to accept that for better or worse, language is fluid, and word definitions change. For instance, you go back to a very old definition of the word "gay", but I can assure you that Enid Blyton meant no such thing in her children's books in the 40s and 50s, when she described Noddy and Big Ears as having a gay time in the woods, or the Famous Five playing gaily by the river with their dog.

But then you go on to refuse to accept that the definition or contextual meaning of any word that you personally consider should be fixed for all time, might change to reflect changes in the world that makes common use of that word.

In some ways, it is the way that you pick on tiny facets, and labour them to the point of being excruciating, to defend a position that is often contentious, or even potentially untenable, that gives me the most problem with trying to have a discussion with you. You berate people for not being able to take on an alternative view of something that you consider them to be wrong on, but then flatly refuse to even consider modifying your own position.

For right or wrong, the global meaning of the word "digital" *has* changed, and if you refuse to acknowledge this, then it doesn't matter how right you believe you are with the narrow definition that you cling to, in the wider world of electronics, you will continue to be considered by most, to be wrong.

I look forward to seeing any comments that the manufacturers may have on this, but please, don't ask them leading questions that can only have a reply that you can use to defend your position. Try to keep it simple, as in "Why do you insist on calling something that is analogue, digital ?"

Just as a matter of interest, do you consider a circuit constructed of simple logic gates, to be 'digital', even though no numeric values are being handled by it ?

Arfa

Yes, K. End of current transmission. Back to you. "Over" in morse, if you like.

"Arfa Daily" wrote in news:x943l.24237$ snipped-for-privacy@newsfe01.ams:

When talking to others, it is 'better' to use the meaning of the word, as THEY define it.

There is nothing to prevent you from saying [often to yourself] '"normally", I use that word to mean xxxxx [but in this case I will use your definition so we can communicate].'

I am just trying to point out the fact that it is "pointless" to 'argue' over the meaning of a word. Either you choose to agree upon a meaning so you can communicate, or you misunderstand or are "mistook". :)

I ENJOY playing with words and will often go a mile out of my way to make a pun.

I think that you usually do well.

As I said, the conversation has been intersting and educational.

di-di-di-dah-di-dah

tu su dit dit

OK. I see what you are saying. What I am saying is that it seems to now be accepted, pretty much world-wide, that the meaning of the word "digital", in the context of modern electronics, and specifically to this debate, amplification, has changed (expanded ?) to encompass topologies and design schemes, that do not fit into the older, narrower definition, as embraced and strictly adhered to by William. As I am using the word in its majority context, as is evidenced by the huge number of references on the web, then I consider that I *am* using the word as the majority on here *would* define it, and it is William who is not. Do you think that is a fair and reasonable assessment of what we have been dancing around ? If you think I am wrong, please feel free to say so. I will not be offended, and will consider your reasoning, to see if it reverses, or modifies my position.

I don't believe, however, in this particular case, that it serves any useful purpose to the general understanding of the class D topology, to ignore the vast weight of manufacturers data where it *is* defined as being digital, in favour of William's contention that it is actually analogue.

Thank you for that.

CW was never my preferred mode. Is that a 'final' final ? If so, back at ya, OM d;~}

Arfa

Why should I, when I'm right? We don't take a vote on whether the Earth is flat, or similar issues. Some things are objectively true, others are a matter of opinion, and not debatable. This is one of the latter.

I don't care much for RegeR's music (which might be poor music in some "objective" fashion), but I listen to it occasionally to see if my taste has changed. But if some tells me that he has proof Special Relativity is wrong, I'm not like to consider modifying my opinion that it's right.

(Amost) whenever someone tells me I'm wrong about something, I give it careful consideration. And you know what? I'm often wrong.

That's not an unreasonable question.

The answer is "yes", because the output of the circuit is presumably one of two logic states -- 0 or 1, true or false. Digital is about quantization -- not numbers, per se.

This is what gets so many people torqued up. When I point out that quantizing a signal level converts it to digital, they start yelling "Where are the numbers!". You don't need numbers. All you need is to reduce the data to a finite number of states or values. And then the data are digital.

Hey you can get 'digital' cables and headphones now for around $3 ! It's the most abused term in the world apart maybe from 'an honest politician'.

Graham

Oh goody goody, how about a digital antenna!