| ghemink |
| quote: | Originally posted by bachiano
Thanks
Bachiano |
Class T is just another Class D. Guess the T was chosen to distinguish themselves from the others.
Best regards
Gertjan |
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| panomaniac |
| quote: | Originally posted by ghemink
Class T is just another Class D. Guess the T was chosen to distinguish themselves from the others.
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Not at all! :att'n: Yes, class-T is a switching class amp, but is is substantualy different from class-D.
Class-D generally uses a PWM triangle wave to modulate the switched output signal. Switching frequencies are usually not far above the audio band, e.g. 100kHz.
Class-T is much more sophisticated. It uses a square wave that changes duty cycle to modulate the signal. Resting duty cycle is 50%. The switching frequencies in class-T are also much higher than in typical class-D. The lowest frequency used in class-T is 600kHz, and is typicaly 700~1000kHz . The switching frequency changes according to the audio power and a few other factors.
Higher switching frequencies make filtering the class-T output easier than class-D. The spread spectrum of the class-T helps efficiency as well. There are other things going on, like precise control of the switchng transistors, but those could apply to class-D as well.
Class-T is unique to Tripath, you won't find it elsewhere. I don't know what they are doing inside the chip to process the audio, but they've done a fantastic job. The results are plain to hear.
Neither of these are really a digital amp. Maybe they should both be sub-classes of a class-S. |
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| flo |
@panomaniac: You've got this definition from Tripaths Application Note AN-2, right? No offense meant, but there is a lot of marketing-bs in this note..
Ghemink is right with his definition: Class-D is used for all switching audio amplifiers. Class-T is just one possible implementation. Others include the fixed-frequency amps using a triangle wave to generate the PWM signal you already mentioned or self-oscillating amps like the UCD or ZAPpulse.
Best regards,
Florian |
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| phase_accurate |
Tripath uses either some form of hysteresis modulator or a "classic" DS modulator. Both of them cause a dropping switching frequency with increasing amplitude.
This has advantages and disadvantages, although Tripath wants us to believe that it only has advantages.
But the marketing guys went one step further and boldly call it spread-spectrum.
But the Tripath amps are definitely class-d although not of the PWM type.
Regards
Charles |
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| panomaniac |
| quote: | Originally posted by flo
panomaniac: You've got this definition from Tripaths Application Note AN-2, right? No offense meant, but there is a lot of marketing-bs in this note..
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I got it from the app notes, yes, and also from looking at the signals and trying to build my own class-D amps.
There certainly is marketing hype in the Tripath claims, of course. Fundamentaly the classes are similar, but in the details they are different enough to warrent the new name, IMO.
As I said, perhaps these should be sub-classes of a larger Class-S (switching).
But we give different names to class A & B, and even a so-called class AB. Those are no more different than Class-D and Class-T.
What's in a name? :rolleyes: |
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| classd4sure |
Hm...
Come on guys, spell it right and there wont' be any confusion:
Class T "TM" for trademark!~
It's a marketing gimmick, nothing more.
How about class N?
Same thing.
I wish people on the forum would stop using the term.
The only switching frequency imposed on class d is caused by the components themselves, if you could make it happen at 10Ghz it would still be class d.
Got to keep a keen eye out for the snake oil anyway.
Cheers,
Chris |
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| panomaniac |
I won't argue that the appellation "Class-T" is a bit of marketing. How do you get to declare your own class?
But isn't what Tripath are calling class-t different enough from other switching amps to merit a new class?
As I said above - are class A, B and AB different enough to earn a unique name? I think so. Or should they all be lumped under "Class-L" for linear? Would that be useful?
Sure, it's a bit cheeky for Tripath to "invent" their own class, but the technique is different enough to deserve it.
I don't see the snake oil in it, just a bit of the usual audio hyperbole. |
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| phase_accurate |
Class-d amps switch between two rails (sometimes more) and the info is in the pulse density.
This is done within ordinary PWM and Tripath amps as well so no reason to call it an own class.
Regards
Charles |
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| tlf9999 |
a much simpler way is for you to go through Tripath's claims one by one and compare it with other class D amps then you will be clear as to what is marketing BS.
Take the IRAudAmp1 for example: it modulates on square waves, at about 500khz, with a "resting" duty cycle of 50%.
| quote: | Originally posted by panomaniac
Neither of these are really a digital amp. Maybe they should both be sub-classes of a class-S. |
it depends on how you define "digital". |
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| phase_accurate |
There were never any digital amps, there are no digital amps and there wil never be any digital amps out there.
Simple as that !
Regards
Charles |
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| e96mlo |
| quote: | Originally posted by phase_accurate
There were never any digital amps, there are no digital amps and there wil never be any digital amps out there.
Simple as that !
Regards
Charles |
Then what about the PDM amplifiers? |
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| tlf9999 |
| quote: | Originally posted by phase_accurate
There were never any digital amps, there are no digital amps and there wil never be any digital amps out there.
Simple as that !
Regards
Charles |
it depended on how you define digital amps; it depends on how you define gitial amps; and it will further depend on how you define digital amps.
simple as that! |
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| Jaka Racman |
Hi,
like all other amplifier classes, class D is defined by the state of the output devices. In class D, output devices are either totally on or totally off and act as switches. That is fundamental to class D. Type of modulation is totaly irelevant.
And before you start another fruitless debate about class D and digital, please reread Difference betweeen Class D and "Digital Amplifiers" .
If you can come up with some arguments that were not covered in that thread you're welcome to post more.
Best regards,
Jaka Racman |
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| phase_accurate |
At first, one should consider what digital actually means: Processed/presented in numerical form.
You can store data, make calculations and logic decisions in the digital domain.
But an amplifier doesn't output numbers but voltage and current !
Regards
Charles |
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| panomaniac |
So can we say that "Class-D" is a misnomer and that all these amps should be called "Class-S" for switching?
Would the different flavors of this class get thier own letters? D-T-J-whatever? |
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| Jaka Racman |
Hi.
I am under impression that you think that class D stands for digital. No more than class A stands for analog. It was simply the first letter that came along after class C (which is rarely mentioned because it is used in RF transmitters IIRC). Besides that, there is class E which is similar to class D, only switches operate in resonant mode.
After E, you have to invent new operational state of output devices, for the letter meaning anything else than the marketing BS.
Best regards,
Jaka Racman |
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| phase_accurate |
I do not see why we should use S instead of D.
I think you are misunderstanding the meaning of the "D" (like marketing- and sales-people usually do). It has nothing to do with DIGITAL like class A has nothing to do with analog.
They are just operating classes that have been defined a long time ago. A to C are non switching classes defined by the angle of the current-flow through their output devices:
A:360 deg
B:180 deg
AB: >180 deg
C: < 180 deg
And D was just used for the next in line, i.e. the switching amp using pulse-density or pulse-width to represent the signal. There is also sonme switching amp class that is designated E.
The next ones interesting for audio are G and H and are used to name amps of classes A, AB or B with modulated or multiple PSU rails.
Regards
Charles
Edit: I now see that Jaka was quicker than me |
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| tool49 |
I know what a digital amp is! It is an amp to which when you input a "1" it ouputs a "1"!
Hehe, sorry couldn't resist!
Sébastien |
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| Jaka Racman |
| quote: | originally posted by phase_accurate
I now see that Jaka was quicker than me
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Yes, but you were more accurate.
Best regards,
Jaka Racman |
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| ghemink |
| quote: | Originally posted by Jaka Racman
Yes, but you were more accurate.
Best regards,
Jaka Racman |
So I hope by now that everyone is convinced that Class T is just another Class D :-) and that there is absolutely no need to invent Class S or whatever other class that would only lead to more confusion.
Cheers
Gertjan |
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| panomaniac |
| quote: | Originally posted by Jaka Racman
I am under impression that you think that class D stands for digital |
Indeed I was! I know classes A, B & C, but didn't realise that "D" was simply choosen as the next letter. Sort of like hurricanes. It certainly leads to confusion, as witnessed in this thread and others.
We usually see PWM amps referered to as "Digital" and class D, so I am not the only one confused on this term. How unfortunate for this class to land on the letter D. :)
Oh well, it isn't the first time a techniclal term was misused or misunderstood.
We then understand "Class-D" to mean any switching amp, no matter how the switching is done? |
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| anbello |
The classification of amplifier operating mode explained above by jacka and phase is right, we can find it in any good electronics textbook, but i think that who speak of 'digital' amplifier is half right because in a class D amplifier we can bypass one conversion (from (Digital(PCM) -> Analog -> PWM) to (Digital(PCM) -> PWM)) and, before this last conversion, perform some kind of digital signal processing.
Regards
Andrea |
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| classd4sure |
| quote: | Originally posted by anbello
The classification of amplifier operating mode explained above by jacka and phase is right, we can find it in any good electronics textbook, but i think that who speak of 'digital' amplifier is half right because in a class D amplifier we can bypass one conversion (from (Digital(PCM) -> Analog -> PWM) to (Digital(PCM) -> PWM)) and, before this last conversion, perform some kind of digital signal processing.
Regards
Andrea |
I don't think you can be half right though, even if you manage to bypass a conversion, you'd still be wise to view the output stage as an analog beast, in fact if you don't, you wont' stand sliver of a chance in hell of having it work and hold together. That actually goes beyond the output stage as well.
"True digital" is now a marketing scheme at best, it impresses the ignorant consumer, nothing more.
Topology classifications:
"amplifier An electronic device used to increase an electrical signal. The signal may be voltage, current or both (power). Preamplifier is the name applied to the first amplifier in the audio chain, accepting inputs from microphones, or other transducers, and low output sources (CD players, tape recorders, turntables, etc.). The preamplifier increases the input signals from mic-level, for instance, to line-level. Power amplifier is the name applied to the last amplifier in the audio chain, used to increase the line-level signals to whatever is necessary to drive the loudspeakers to the loudness required. See amplifier classes.
amplifier classes Audio power amplifiers were originally classified according to the relationship between the output voltage swing and the input voltage swing; thus it was primarily the design of the output stage that defined each class. Classification was based on the amount of time the output devices operate during one complete cycle of signal swing. Classes were also defined in terms of output bias current [the amount of current flowing in the output devices with no applied signal]. For discussion purposes (with the exception of class A), assume a simple output stage consisting of two complementary devices (one positive polarity and one negative polarity) using tubes (valves) or any type of transistor (bipolar, MOSFET, JFET, IGFET, IGBT, etc.).
[Historical Notes marked "GRS" provided by Gerald R. Stanley, Senior V.P. of Research, Crown International, Inc., designer of the famous Crown DC-300, inventor of the Crown K Series switchmode amplifier line and holder of 20 U.S. Patents, with three pending as of 2003.]
[GRS on amplifiers: "At first there were no amplifiers as the very thought of amplification had yet to enter the vocabulary of electronics (another word which had yet to be birthed!). The invention of a three-terminaled device (DeForest Audion U.S. patent 841,386 or later triode) was the invention in 1906 of a more sensitive radio detector and not an element for an amplifier.
By 1912 the triode had become both a vacuum tube and an amplifier (multiple names can be attached to this collective achievement). The oscillator also dates to 1912 giving proof to the saying "When you set out to make an amplifier you get an oscillator and when you attempt to make an oscillator you get an amplifier."]"
I can't resist saying, it seems the ultimate is to combine the two:) Welcome to self oscillating class D.
"[GRS on amplifier classes: "Originally it was adequate to distinguish amplifier classes only by the conduction angles of the control elements (tubes or valves). More recently it has been necessary to add distinctions that relate to topology, degrees of conduction and control methods to be able to determine class."]"
"[GRS Historical Note: "Class D is a subset of all possible switch-mode amplifier topologies that is typified by use of the half-bridge (totem-pole) output stage that has two interconnected switches operating in time alternation. The paradigm is that of Loy Barton's class B, but uses the statistics of conduction angle to produce amplification (PWM). There are many subclasses within class D that describe the origins of the modulation. Class D is at least as old as 1954 when Bright patented a solid-state full-bridge servo amplifier U.S. 2,821,639."]"
1954!!!!!!!! and they only got good .... yesterday :) Isn't that fun?!?? Now you see why some still fear it, however I understand the very first cars were lucky if they could make it to the end of the street that they started on, yet I dont' see many horse and buggy/carriages around today other than for novelty, they're no longer practical. I find tubes to be a novelty as well, but it seems bad guitar players love them. :devilr:
If you liked that, you'll love this.
There's already a Class S, or at least there was, just try and guess what it was?!
"Class S First invented in 1932, this technique is used for both amplification and amplitude modulation. Similar to Class D except the rectangular PWM voltage waveform is applied to a low-pass filter that allows only the slowly varying dc or average voltage component to appear across the load. Essentially this is what is termed "Class D" today. See References Krauss for details."
How they differed:
"[Historical note: the original use of the term "Class D" referred to switching amplifiers that employed a resonant circuit at the output to remove the harmonics of the switching frequency. Today's use is much closer to the original "Class S" designs.]"
All quotes came from here:
http://www.rane.com/par-a.html
I find www.rane.com an excellent info packed site, know it.
Regards,
Chris |
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| TerryG |
I really wish Tripath and other companies would not invent their own amplifier classes, this has been so confusing for so many people including myself. In the end when you figure out the truth your respect for those companies goes way down, because you realise what they are doing is all about the money. Not that money is important, but the merit of their ingenuity should stand on its own and drawing attention to it is nothing more than bragging for the sake of misleading others into thinking your mysteriously better.
So either a company has a technology that significantly improves said technology or it doesn't. The proof will be in how it is accepted as such by the scientific community, and that will add credibility in a far more substancial way than attempts at decieving the ignorant or creating false amplifier classes.
Take Halcro for example, they added no new classification for their amplifiers, which on very short order were accepted as being ground breaking by the general electrical engineering community. So much so that they can fetch incredibly large prices for their products, and justifiably so. In time I hope that their technology will be more widely used at a significantly lower cost. They are already making a class D line for home theater applications.
Terry |
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| bachiano |
In This World there is a big divide between the Engineering Dept. and the Marketing Dept.
"The proof will be in how it is accepted as such by the scientific community, and that will add credibility in a far more substancial way"
on The subject of science / Scientist talk and nobody listens i.e. Global Warming.
Scientist have no credibility in The U.S. At least.
"than attempts at decieving the ignorant or creating false amplifier classes."
There is nothing false about it - Osterizer is now synonymous with Blender.
It is just a name. It is meant to stick in your mind so you won't forget "it".
Just Thinking outloud
Bachiano :D |
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| classd4sure |
| quote: | Originally posted by bachiano
In This World there is a big divide between the Engineering Dept. and the Marketing Dept.
"The proof will be in how it is accepted as such by the scientific community, and that will add credibility in a far more substancial way"
on The subject of science / Scientist talk and nobody listens i.e. Global Warming.
Scientist have no credibility in The U.S. At least.
"than attempts at decieving the ignorant or creating false amplifier classes."
There is nothing false about it - Osterizer is now synonymous with Blender.
It is just a name. It is meant to stick in your mind so you won't forget "it".
Just Thinking outloud
Bachiano :D |
It is just a name, but to try and pass it off as a unique class is misleading, proof of which is this thread you started. When this forum first came to be the title originally had "class T" in it, people didn't realize it was a marketing scheme/trademark. We asked that it be changed.
An amplifier topology is much more than a name. I feel that when marketing interferes with facts, it's a problem, which explains my commercial disgust. |
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| TerryG |
This is the problem, many times especially in audio, a manufacture tries to pass something off as better when in reality it is not. The problem comes in not defining how something is better in an absolute way that means something to everyone potentially using the product. In the world of computers, speed and storage capacity are the primary areas of concern, either something achieves one of those two areas or it doesn't. Even if they do, it can't be at the cost of losing things, memory loss or the like.
In audio, marketing not nearly on the level of the home computer market. There is so much snake oil in audio that when a company remotely resembles it is doing this, nothing can turn me off faster. The amplifier class distinctions were not developed by those making marketing strageties, but by scientists, so for those marketing to feel they have the right to issue new amplifier classes is overstepping their bounds. It clearly shows the level of integrity that they are at, and willing to go to for the their own sake. Likewise it shows that they feel their technology obviously needs more help than its own merits. The best advertisement is thrid party, or word of mouth as they say. If the scientific community decided that Tripaths technology was so unique that it deserved its own amplifier class, then that would be far more impressive, than a marketing sceem that looks like snake oil.
Besides all that I feel they do have some very good products, and they are doing a great service for the audio word. Just not in the most honest way.
Terry |
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| attilio7 |
Besides all that I feel they do have some very good products, and they are doing a great service for the audio word. Just not in the most honest way.
Terry [/B][/QUOTE]
Hi I am one of the new converts to this hobby, a lot of the posts go way above my head but I enjoy reading them, and try to understand as much as possible. There must be hundreds like me on this website who's introduction to class D was the Sonic Impact T-Amp. Tripath of course don't deserve any special praise, but the T-Amp was the perfect package to demonstrate to the music lover how they have been ripped of by Hi-Fi manufacturers for years, with overpriced products. With very little skill the music lover can with an already assembled module autocostruire, Charlize , etc. construct an amplifier of very high performance for very little money.
regards
attilio |
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| bachiano |
"There must be hundreds like me on this website who's introduction to class D was the Sonic Impact T-Amp. Tripath of course don't deserve any special praise,"
Why is everyone so down on Tripath - As far as I know, the sonic t-amp is a Tripath -
So they must get most of the Credit.
"but the T-Amp was the perfect package to demonstrate to the music lover how they have been ripped of by Hi-Fi manufacturers for years, with overpriced products."
I'm not sure you are 100% right on this.
Maybe you are right when it comes to the consumer "hi fi" they sell in sound advice,
but not when it come to hi fidelity.
It is dificult and expensive to achieve real hi fidelity with technology that is
20% to 50% efficient, even if you DIY.
The reason this technology is so inexpensive is because of it's efficiency and low parts count. |
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| classd4sure |
I think you can comment on their marketing practices without relevance to their products.
I don't believe efficiency draws much of a parallel with high quality, look at class A. If you think it's difficult making a good class A, try it with a class D sometime, different ballgame.
I also have no idea where you get the idea it's so inexpensive? If you're talking about a sonic impact OK, but look at it. It's not a UCD or a ZAPpulse or Icepower, it's more of a gainclone.
If you want cheap and inexpensive, off the shelf is where you find it. |
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| TerryG |
I don't know, this is the most exciting thing about Class D, you don't need the huge expensive power supply, or the large heat dissipating heat sinks. These things lower cost, and you get the same if not better fidelity, than a class A amplifier. I have not heard the sound quality with class A as with class D. I have some class A amplifiers, even they can't match a really good class D. This is why I am pursuing class D amplfiers, likewise you don't need as much wattage as audio manufactures lead us all to believe at one time.
The facts of audio has changed because of the internet. Audio manufactures, can no longer mislead the consumer like they have for years to line their own pockets. I was told that the single most basic inprovement you can make to a system was a more powerful amplfier. I was also told that the more drivers you have in a speaker the better the sound quality. I was also told the you get what you pay for, more money means better sound. All of these things are just not true, they were misleading statements by salesmen, audio reviewers, their maganzines, and their advertisements.
Tripath and others are doing great things for the audio world, and it is just getting started. A sonic impact is just scratching the surface, there is so much more, and will be even more to come.
This doesn't make it right to market things in a misleading way, and Tripath has done this much with their class T campaign.
Terry :cool: |
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| bachiano |
Hi Terry, you've hit it right on the nail.
And now my responce to classd4sure.
"I think you can comment on their marketing practices without relevance to their products."
Yes you can, but attilio7 did not make that distinction.
"I don't believe efficiency draws much of a parallel with high quality, look at class A."
I'm not sure I understand what you are saying above.
I did not use the word "Quality" anywhere in my last post.
all I said was that "It is difficult and expensive to achieve real hi fidelity with technology
that is 20% to 50% efficient, even if you DIY.
Anyway, What does Quality have to do with Class A???
"I also have no idea where you get the idea it's so inexpensive?"
Let's see - compare any class d module offered today i.e. UCD, ZAPpulse, Icepower etc.
to the example below.
A UX-245 will cost me $90 to $200. and I need two.
For a cheap OT with a lousy freq. response - $100.
and for a good one $500 to $1000. and I need two.
If you go with IT trannies $100 to $200 - with caps not too bad.
and then there is all the little bits that make the whole thing work.
AND I almost forgot the PS. You know How big the trannies are that step up to 350 volt -
not to mention the ones that have to power transmitter tubes ? Big is expensive.
"If you're talking about a sonic impact OK, but look at it. It's not a UCD or a ZAPpulse or Icepower, it's more of a gainclone."
I was thinking of old inefficient technology i.e. Tubes = an old fashion DIY pure class A
single ended amp that needs 350 Volt DC and puts out two watts
VS.. the efficiency of Class D = 12VDC in 10 watts out.
This is what I meant by Hi Fidelity , Low Efficiency and High price.
"If you want cheap and inexpensive, off the shelf is where you find it"
I did get all my part of the shelf.
"If you think it's difficult making a good class A, try it with a class D sometime, different ballgame."
I don't think I implied that difficulty was part of the formula?
Bachiano |
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| carlosfm |
| quote: | Originally posted by phase_accurate
There were never any digital amps, there are no digital amps and there wil never be any digital amps out there.
Simple as that ! |
| quote: | Originally posted by phase_accurate
At first, one should consider what digital actually means: Processed/presented in numerical form.
You can store data, make calculations and logic decisions in the digital domain.
But an amplifier doesn't output numbers but voltage and current ! |
RIGHT!
In the beginning and in the end, everything is analog.
:cool: |
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| bachiano |
"This doesn't make it right to market things in a misleading way, and Tripath has done this much with their class T campaign "
Could some of you post examples / links that demonstrates this misleading campaign.
I can't find any.
Thanks
I found this interesting link
But did not find anything misleading in it.
check out the "Master your A-B-Ds: A digital-amplifier glossary" near the bottom.
http://www.reed-electronics.com/com...te=5%2F1%2F2001
here's another with defenitions of Amplifier classes
http://ldsg.snippets.org/appdx-d.php3 |
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| classd4sure |
How about the mere fact they call it "Class T" when there is no such class, I thought that was obvious, but.. it's hard to decipher the hype from the facts because there's so much hype and they push it so well.
From their own website, just a few of what I'm sure are many examples of the same:
"In the audio arena, DPP® has given rise to a new class of true digital audio amplifiers, known as Class-T®. Our technology provides a combination of fidelity, power efficiency and economy far superior to the Class-A, -AB and -D amplifiers prevalent in current- generation audio. Tripath provides audio amplifier solutions to manufacturers of professional, home, car and PC sound systems. "
Not only are they claiming it isn't class-d (it is) they're claiming it's true digital (far from it).
Yet on the same page below:
"Tripath markets audio amplifiers with DPP(R) under the brand name Class-T(R). " Key word being "brand name".
Contradicted themselves. So, is it a new class of amp, or a brand name? They're trying to tell you it's both.
So while there they admit it's a brand name/trademark, they keep saying it isn't class-d, leading you to believe it's a unique amplifier class, something other than the trademark which it is.
Read their whitepaper for many more examples:
http://www.tripath.com/downloads/an1.pdf
From your link, Class J is no better in this marketing scheme.
"Class Jam" From Jam Technologies
"Class Tripath", "True digital" From Tripath
"Class N" From N-Force
and I quote "Switching Digital Amplifiers (commonly known as Class-D) were introduced some years ago. Right from the start, Class-D had enormous potential but some significant shortcomings. For example, they have limited usable bandwidth, and they use a fixed sawtooth waveform to modulate an audio signal. This is a source of audio pollution, because the waveform causes inevitable jittering that can mask or corrupt low-level music signals.
Instead of a sawtooth digital signal, Nuforce has developed and patented a naturally occurring analog modulating signal that flows with the music and adds no noise or jitter into the system.
Rather than using imperfect off-the-shelf solutions, Nuforce has developed and patented a series of breakthrough advances that have unlocked the huge potential of switching amplifiers, without the problems that pure digital switching amplifiers have been unable to solve.
In other words, the best of both worlds"
First off, switching amps aren't "digital", "digital" does not mean "class d", they based their work off powrephysics, parent company, so not entirely revolutionary, neither is it new.
It's little wonder you're confused, with this level of BS out there. They're alllllllllll class D, non of them are digital..... etc. |
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| Christer |
| quote: | Originally posted by classd4sure
Instead of a sawtooth digital signal, Nuforce has developed and patented a naturally occurring analog modulating signal that flows with the music and adds no noise or jitter into the system.
|
I didn't know one could patent something that is naturally occuring, even less develop it. ;) |
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| bachiano |
and another
http://www.crutchfieldadvisor.com/S...iew.html?page=3
here Todd Cabell of Crutchfield Advisor is talking to Shawn Scarlett, Senior Product Marketing Manager at Tripath.
This is what Scarlett says about Tripath :
"Class-T® is the name for our proprietary architecture that improves on general switching amps. We use a combination of "predictive" and "adaptive" processing. On top of that, we use a very high switching frequency. The basic idea is that we look at the incoming signal to determine the best way to encode it, making sure to minimize interference or mistakes. We then use feedback, or "adaptive" processing to analyze the output and keep the system stable. The high switching frequency allows us to correct any issues quickly before they become audible. Because of the robustness of the system, we can maintain our fidelity even with mismatches in the output FETs [Field Effect Transistors], power supply "ripple", and other issues that normally require significant engineering time and manufacturing cost to prevent. The Class-T® technology allows us to reach very high fidelity levels and keep THD+N [Total Harmonic Distortion plus Noise] figures better than many A/B amplifiers, while still delivering the efficiency of a switching amplifier. "
He is saying that "Class-T®" is the NAME for their "proprietary architecture".
You can see the registered trademark ® at the end of Class-T.
And I think we all know what that little ® means, Right? - Brand Name.
I could not find any examples where anybody at Tripath is Saying that their amps are anything other than Class-D.
Quote ; "Class-T® is the name for our proprietary architecture that improves on general Switching Amps" i.e. Class-D
Nothing misleading here.
Bachiano |
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| classd4sure |
| quote: | Originally posted by bachiano
and another
http://www.crutchfieldadvisor.com/S...iew.html?page=3
here Todd Cabell of Crutchfield Advisor is talking to Shawn Scarlett, Senior Product Marketing Manager at Tripath.
This is what Scarlett says about Tripath :
"Class-T® is the name for our proprietary architecture that improves on general switching amps. We use a combination of "predictive" and "adaptive" processing. On top of that, we use a very high switching frequency. The basic idea is that we look at the incoming signal to determine the best way to encode it, making sure to minimize interference or mistakes. We then use feedback, or "adaptive" processing to analyze the output and keep the system stable. The high switching frequency allows us to correct any issues quickly before they become audible. Because of the robustness of the system, we can maintain our fidelity even with mismatches in the output FETs [Field Effect Transistors], power supply "ripple", and other issues that normally require significant engineering time and manufacturing cost to prevent. The Class-T® technology allows us to reach very high fidelity levels and keep THD+N [Total Harmonic Distortion plus Noise] figures better than many A/B amplifiers, while still delivering the efficiency of a switching amplifier. "
He is saying that "Class-T®" is the NAME for their "proprietary architecture".
You can see the registered trademark ® at the end of Class-T.
And I think we all know what that little ® means, Right? - Brand Name.
I could not find any examples where anybody at Tripath is Saying that their amps are anything other than Class-D.
Quote ; "Class-T® is the name for our proprietary architecture that improves on general Switching Amps" i.e. Class-D
Nothing misleading here.
Bachiano |
:cannotbe: This is near aggravating, you ask the question, then you disagree and tell me the answer. Are you sure you don't work for Tripath, maybe? Perhaps you're on the verge of releasing a class Bachiano amplifier? hmmmm?
From Tripath's FAQ available at http://www.tripath.com/faq_pr.htm:
Q: What does "Class-T" mean and how does it differ from Class-D Pulse Width Modulation?
A: Class-T represents a proprietary technology for how Tripath does amplification. We chose the Class-T designator to differentiate ourselves from Class-D technology because our technology does not use Pulse Width Modulation, which is synonymous with Class-D, and it is not a pure analog approach like Class-AB. Tripath uses an adaptive/predictive algorithm to drive output transistors that achieve the high fidelity of Class-AB amplifiers with the power efficiency of Class-D amplifiers. A more detailed discussion of this is available on our web page titled Class-T White Paper."
Do you see a trademark designation in that? I don't. Do you see them telling you it isn't class d? I do.
Further, look at the table they provide to the question:
"Q: How does the Tripath Class-T amplifier compare with Class-A, Class-AB and Class-D amplifiers? "
'nuff said there.
One last quote, this time from their whitepaper:
"Class-T provides power conversion efficiencies of 80 percent to more than 90
percent, which is equal to or better than Class-D amplifiers." ..... and yet, it IS a class D amplifier.
I don't care if they put a little "R" in the fineprint. It is misleading, and has obviously mislead you.
Now you can answer that however you like, the facts stand on their own, I will find a more productive thread to kill time in, all this stuff is reeaaaal old news. |
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| classd4sure |
| quote: | Originally posted by Christer
I didn't know one could patent something that is naturally occuring, even less develop it. ;) |
:D |
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| carlosfm |
This discussion reminds me the FM tuners of 20 years ago.
They had 'DIGITAL' is capital letters (and stickers) on the front, while they were analog, with digital tuning.
The lettering was usually like 'Digital AM/FM Stereo tuner'.
Then it came RDS. The 'DIGITAL' lettering grew up even more, along with 'RDS', 'TEXT', etc.
Now you see DAB tuners with 'DIGITAL' on it. Makes a little more sense.
It even went to the ridiculous 'Digital TV', while it only had a digital tuner.
They can say what they want. |
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| Christer |
| The marketing departments love to use certain words and they do whatever they can to get an excuse to do so. Digital is such a word, but there are many other. Many years ago I heard a story about one of the big manufacturers of microwave ovens (doesn't matter which one it was). The marketing department had realized that there was a new (to the industry) technology called "fuzzy logic control" which some companies were starting to use. They demanded that the engineering department put some fuzzy logic control into the ovens, so they could say so in the marketing. Of course there was no reasonable way to find some sensible use for it in a microwave oven, but marketing was persistent, so the engineers had to put a fuzzy logic controller in the ovens to do something that could have been done in a simpler and cheaper way. Now the marketing guys could sell microwave ovens with fuzzy logic control. I am sure one could find similar (mis)uses of the word digital in audio. |
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| classd4sure |
| quote: | Originally posted by Christer
The marketing departments love to use certain words and they do whatever they can to get an excuse to do so. Digital is such a word, but there are many other. Many years ago I heard a story about one of the big manufacturers of microwave ovens (doesn't matter which one it was). The marketing department had realized that there was a new (to the industry) technology called "fuzzy logic control" which some companies were starting to use. They demanded that the engineering department put some fuzzy logic control into the ovens, so they could say so in the marketing. Of course there was no reasonable way to find some sensible use for it in a microwave oven, but marketing was persistent, so the engineers had to put a fuzzy logic controller in the ovens to do something that could have been done in a simpler and cheaper way. Now the marketing guys could sell microwave ovens with fuzzy logic control. I am sure one could find similar (mis)uses of the word digital in audio. |
Yeah and you wouldn't have to go far to find it either. In fact it's so commonly done I'm forced to grant Tripath that one thing. It's when they start inventing the words that I lose respect.
Edit: Although they seem to be claiming "true digital" these days. That's a different story again. |
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| Christer |
| quote: | Originally posted by classd4sure
Yeah and you wouldn't have to go far to find it either. In fact it's so commonly done I'm forced to grant Tripath that one thing. It's when they start inventing the words that I lose respect. |
Yes, but I was thinking of doing something digital that doesn't need to be done digitally, just to get an excuse to write digital on the front. But of course, some companies like Tri-Path don't even bother if what they call digital is digital. In either case, it is a marketing trick to mislead customers.
There was another funny store during the fuzzy-logic hype. Some japanese company used fuzzy logic control for autofocus in video cameras (which maybe could be justified). However, they didn't realize they had better keep shut about it. The customers didn't understand why they should buy a videocamera with fuzzy focus. :) |
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| carlosfm |
| quote: | Originally posted by Christer
Now the marketing guys could sell microwave ovens with fuzzy logic control. |
Fuzzy logic control on microwave ovens?
What about 'Fuzzy Logic Quartz-Locked Direct Drive Turntable'? :clown:
:cool: |
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| classd4sure |
| quote: | Originally posted by Christer
Yes, but I was thinking of doing something digital that doesn't need to be done digitally, just to get an excuse to write digital on the front. But of course, some companies like Tri-Path don't even bother if what they call digital is digital. In either case, it is a marketing trick to mislead customers.
There was another funny store during the fuzzy-logic hype. Some japanese company used fuzzy logic control for autofocus in video cameras (which maybe could be justified). However, they didn't realize they had better keep shut about it. The customers didn't understand why they should buy a videocamera with fuzzy focus. :) |
Hah. Nice when it backfires.
Actually I made a mistake they don't claim "true digital"
Here's an interesting link with will burry this thread.
http://www.tripath.com/downloads/an2.pdf
One can see here that while it is an admitted trademark, they obviously do, and always have, intended it as a class of it's own, apart from class D.
According to your points however, I'm somewhat sure they dont' even use any sort of DSP to time the switching of the outputs, from their patents it's all done via analog means, I'm sure Charles can comment on that further. |
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| classd4sure |
| quote: | Originally posted by carlosfm
Fuzzy logic control on microwave ovens?
What about 'Fuzzy Logic Quartz-Locked Direct Drive Turntable'? :clown:
:cool: |
How about "Natural Spring Water" that comes in a bottle :) |
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| bachiano |
Ok -classd4sure- I read the white paper and I think I see the confusion.
"How about the mere fact they call it "Class T" when there is no such class, "
This is my Dictionary defenition of Class:
Class |klas| noun 1. a set or category of things having some property or attribute in
common and differentiated from others by kind, TYPE, or quality.
TYPE is the important one here. They are using Class as a Synonym for Type.
Not an improper use.
Replace Class-T with Type-T and the problem is gone.
"From their own website, just a few of what I'm sure are many examples of the same:"
"In the audio arena, DPP® has given rise to a new class of true digital audio amplifiers, known as Class-T®. Our technology provides a combination of fidelity, power efficiency and economy far superior to the Class-A, -AB and -D amplifiers prevalent in current- generation audio. Tripath provides audio amplifier solutions to manufacturers of professional, home, car and PC sound systems. "
"Not only are they claiming it isn't class-d (it is)"
I did not see that anywhere.
"they're claiming it's true digital (far from it)."
"new class of true digital audio amplifiers"
Look near bottom of this post.
"Yet on the same page below:
"Tripath markets audio amplifiers with DPP(R) under the brand name Class-T(R). " Key word being "brand name".
Contradicted themselves. So, is it a new class of amp, or a brand name? They're trying to tell you it's both."
It's a new Type of amp with a new Brand Name.
"So while there they admit it's a brand name/trademark,"
It's not an admission. They are telling us.
"they keep saying it isn't class-d, leading you to believe it's a unique amplifier class, something other than the trademark which it is."
I don't see where they say it's not Class-d
"and I quote "Switching Digital Amplifiers (commonly known as Class-D) were introduced some years ago."
"First off, switching amps aren't "digital", "digital" does not mean "class d", they based their work off powrephysics, parent company, so not entirely revolutionary, neither is it new.
Oxford Dictionary:
Digital |?dijitl| adjective 1 relating to or using signals or information represented by
discrete values (digits) of a physical quantity, such as voltage or magnetic polarization,
to represent arithmetic numbers or approximations to numbers from a continuum or
logical expressions and variables : digital TV.
Digital Radio , Digital Camera, Digital Clock, Digital CD Player, Digital Switch, Digital
Magazine, Digital Eye, Digital Library; God I could go on forever.
Digital amplifier is no different than any of things above.
What they have in common that makes them digital is they have an I/O interface,
either analogue or digital but all have some intermediate digital process.
"It's little wonder you're confused, with this level of BS out there. They're alllllllllll class D, non of them are digital..... etc."
Nope, I'm not comfused. I just know how words are used in our common Lexicon.
Bachiano |
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| bachiano |
Did I make you feel like this :bawling:
I do that to my wife sometimes.
I'm just playing devil's advocate for the sake of a fun debate. :devilr:
I know perfectly well what tripath is doing - they are however IMO harmless when you compare them to other industries.
Bachiano
P.S. Please Don't leave, it was fun :) |
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| classd4sure |
Actually it was boring, captain of the debate team, were you?
I enjoy a good argument, trust me. But the topic should first be interesting, and not with a past determined outcome, that's where you lost this one, and your dictionary isn't going to save you, nor however many times you change the context to suit your purpose.
First it's a trademark so they aren't misleading and now it's a class of its own again, which is it? I already know and wont' be convinced otherwise by you.
Electronics don't ******** you, marketing does, and this isn't a marketing forum.
Furthermore, you're making yourself appear foolish. Quoting the dictionary?? Really.
If it's an honest question that's one thing, you're simply reducing the signal to noise ratio around here at this point, and I don't think I can hear you anymore.
I'd just like to close with.. "yawn" |
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| bachiano |
I was trying to finish this nicely.
"I enjoy a good argument, trust me. But the topic should first be interesting,"
It was interesting for me!
" and not with a past determined outcome,"
Actually that is the point of a debate - you pick a side and try to win at all cause,
even if you don't subscribe to you're own side.
Debate is just a forum for learning. Not for ------- people off.
"Electronics don't ******** you, marketing does, and this isn't a marketing forum."
This is not nessesary I'm here because I love music.
Furthermore, you're making yourself appear foolish. Quoting the dictionary?? Really.
Really? How is that foolish. That's what my mom taught me -" make sure you are using words correctly. Check the Dictionary" People are always fighting because they misinterpret words.
"If it's an honest question that's one thing,"
It was an honest Question - When I first asked the question I really did not know.
People were saying that tripath was being misleading and I did not see how.
Bachiano |
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| classd4sure |
How did you think I'd respond to being quoted to by the dictionary?
You say you didn't know, and that's OK, but then why play devil's advocate as you say? That's where it starts going downhill my friend, and becomes foolish, I'll elaborate on that in a bit.
You also still say you don't see any examples where Tripath makes the claim that they're something other than class d, I've provided you with many examples of exactly that. Then you argue it's a trademark and so not misleading, quotes from which came from Cruthfield, who was correct to overstate that it is a trademark, unlike Tripath, who put it in the fine print, and then go on to say "we aren't class D, class D baaaad", and they've dedicated an entire app note "an2" which I linked you to, saying Class T is not class D. So is it a trademark or a class? According to them it would be both, they're only half right.
Then you start quoting the dictionary trying to say Class T is different and so it's correct, manipulating the meaning of the word "class", and poorly I might add, for as you say, it is synanomous. You further failed to establish how it's different. We've established already it's a class d amp, so your whole Type T argument is laughable, also synamous with foolish, as per the linked definition.
I think you're trying to end this on a note where you save face. Maybe you should just ask a mod to delete this thread, I won't mind.
A better method would be to put a little more forthought into your posts and avoid that situation by not choosing to further debate a dead end, which I find to be foolish.
According to the definition of foolish I believe I used the word appropriatly on every account.
Shame on me for having sunk this low. Hope to see you in Texas, yes? |
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| theAnonymous1 |
I don't agree with Tripath using "Class-T" to label their product, but their not the first and surely not the last to use such marketing to sell something.
It really doesn't matter in the end, the majority of people who buy a Tripath product do so because of factors like cost and performance, not because its called "Class-T".
Besides, if you bought an amp thinking it was some new class of its own and enjoyed the sound it put out, and then someone rains on your parade and tells you its not what you thought it was, would it change the way it sounds? |
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| Netlist |
:cop:
Guys, lets refrain from getting personal.
/modhat off
Martini is a drink that comes to mind, originally it's a cocktail and still is but some smart guys made it a trademark. Doesn't make the homebrew stuff less tasteful. :cool:
/Hugo |
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| classd4sure |
| quote: | Originally posted by theAnonymous1
I don't agree with Tripath using "Class-T" to label their product, but their not the first and surely not the last to use such marketing to sell something.
It really doesn't matter in the end, the majority of people who buy a Tripath product do so because of factors like cost and performance, not because its called "Class-T".
Besides, if you bought an amp thinking it was some new class of its own and enjoyed the sound it put out, and then someone rains on your parade and tells you its not what you thought it was, would it change the way it sounds? |
You make some good points there. It's not that a big a deal, providing you know the difference. I disagree with it strongly for the reasons that there's already such a steep learning curve, "inventing" their own classes add confusion to the matter for anyone who is trying to learn.
If I asked you to draw me a class A amp, you probably could, same with B, D, etc.
Can you draw me a class T amp? No you can't, because it's proprietary class D, all you can do is draw me an outline of an IC, which isn't a topology. So that's where I don't like it.
Now you have the Class N stuff I posted from Nuforce doing the same, you could actually spend a few years working on a very good class d amp design, try to get it patented though, it already exists and you didn't know it because they called it class N and your searches didn't turn that up.
So in a world where things are confusing enough, why add to it?
Let's redefine "class" as it stands today, while before it was on conduction angle/level of bias, today its' anything the markerting department say's. I choose not to agree with that.
The ultimate fear is that this becomes accepted as a class due to ignorance and common usage. Maybe this thread has a purpose after all :) |
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| bachiano |
"The ultimate fear is that this becomes accepted as a class due to ignorance and common usage."
That won't happen here - a heated debate is a good thing, as long as you learn, give each other a pat in the back and have a Beer or Martini afterwords.
"Maybe this thread has a purpose after all "
Ofcourse it does.
"Bachiano the Fool"
:clown: |
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| carlosfm |
| quote: | Originally posted by bachiano
Did I make you feel like this :bawling:
I do that to my wife sometimes. |
:D :D :D
After such a confession I could not pick on you anymore.
Classd4sure, this is the man to buy you a drink.
Martini, on the rocks, please. |
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