A subjectividade no mundo das vàlvulas...

TD124 escreveu:

ricardo onga-ku escreveu:

mannitheear escreveu:

...

TD124 mentioned feedback, but what type of distortion is caused by feedback?

...

Nelson Pass on negative feedback: http://www.firstwatt.com/pdf/art_dist_fdbk.pdf

R

Hi Manfred,

this is an excellent link to answer to your doubts!, its more tecnical, but Nelson Pass explains you with consise and pragmatic words, what i try to say with simple ones, but at the end, mines become simplist !...

Conclusion by Nelson Pass
Time flies, and there is still much to learn. I haven't really touched on what these pictures
mean to an audiophile, perhaps not what Srajan had in mind when he asked for this piece.
In fact, apart from assuming the preference for low amounts of simple forms of distortion, we
haven't discussed the listener at all. Nevertheless, I am trying to make a point that relates
strongly to the apparent disconnect between subjective experience and simple measurements
of distortion.
We have seen that nonlinear distortion becomes larger and more complex depending on the
nonlinear characteristic of the stages, the number of cascaded stages, and the number of
spectral elements in the music.
Negative feedback can reduce the total quantity of distortion, but it adds new components on
its own, and tempts the designer to use more cascaded gain stages in search of better
numbers, accompanied by greater feedback frequency stability issues.
The resulting complexity creates distortion which is unlike the simple harmonics associated
with musical instruments, and we see that these complex waves can gather to create the
occasional tsunami of distortion, peaking at values far above those imagined by the distortion
specifications.
If you want the peak distortion of the circuit of figure 13 to remain below .1% with a complex
signal, then you need to reduce it by a factor of about 3000. 70 dB of feedback would do it,
but that does seems like a lot.
By contrast, it appears that if you can make a single stage operate at .01% 2nd harmonic with
a single tone without feedback, you could also achieve the .1% peak in the complex IM test.
I like to think the latter would sound better.

Cheers, and i'm going to translate it in portuguese, in a way that everybody understands the idea!...

Eu sabia que ias gostar desse artigo.  
Achas que consegues explicar à malta as diferenças entre a aplicação de realimentação negativa (negative feedback) local e global?

R

TD124 escreveu:

afonso escreveu:

Os audiófilos andam-se a rir dos problemas das medições há anos.( se as medições não mostram nenhuma diferença é porque não há diferença audivel...).
...
Talvez só saberemos compreender essas diferenças quando a malta começar a abrir as mentes e inovar novos parâmetros.
...
Agora se me permitem tenho que ir abrir 4 caixotes pesando 80kg que me chegaram hoje no dhl...

Uma frase que tém a ver e que é atribuida a Julian Vereker, fundador da Naim:

We all have a deep respect for Peter Walker and Quad products!... even me...  but no one wants to listen them !... and so do i !!!...
Todos temos um grande respeito pelo Peter Walker e pelos aparelhos Quad!... e eu também!!!... mas ninguém quer escutà-los!... e eu de mesmo !!!...

O P. Walker, era um génio da eléctronica audio (talvez o maior), mas não escutava os aparelhos dele!... e dai talvez a origem desta frase ironica, e uma explicação aos fenomenos dos quais falamos !... talvez a boa via esteja entre estes dois extremos, como pensa o Nelson Pass,... e eu também...

Peut-être!,... mais pas sur!... Até+

Isso é marketing...a Quad era concorrente directa da Naim.

Quando perguntaram ao Peter Qvortrup (Audio Note UK) qual era a marca da concorrência que mais admirava esta foi a sua resposta:

"I like Naim."

Porquê

"I don't like their sound, but I do like the way they operate as a company, they way their product build up to a full system with upgrade routes pre-planned, they way they communicate and treat their customers. Naim is in an enviable position as their customers are very loyal, just like Audio Note UK customers!"

O Audio é um negócio e o Julian Vereker é um génio do marketing.

R

ricardo onga-ku escreveu:

[Isso é marketing...a Quad era concorrente directa da Naim.

Quando perguntaram ao Peter Qvortrup (Audio Note UK) qual era a marca da concorrência que mais admirava esta foi a sua resposta:

"I like Naim."

Porquê

"I don't like their sound, but I do like the way they operate as a company, they way their product build up to a full system with upgrade routes pre-planned, they way they communicate and treat their customers. Naim is in an enviable position as their customers are very loyal, just like Audio Note UK customers!"

O Audio é um negócio e o Julian Vereker é um génio do marketing.

R

´Fantástico!!!

ricardo onga-ku escreveu:

TD124 escreveu:

ricardo onga-ku escreveu:

mannitheear escreveu:

...

TD124 mentioned feedback, but what type of distortion is caused by feedback?

...

Nelson Pass on negative feedback: http://www.firstwatt.com/pdf/art_dist_fdbk.pdf

R

Hi Manfred,

this is an excellent link to answer to your doubts!, its more tecnical, but Nelson Pass explains you with consise and pragmatic words, what i try to say with simple ones, but at the end, mines become simplist !...
...

Eu sabia que ias gostar desse artigo.
 
Achas que consegues explicar à malta as diferenças entre a aplicação de realimentação negativa (negative feedback) local e global?


R

Bom o que é o feedback, antes de tudo ?... trata-se de uma astucia inventada por Harold Black em 1927 !!!, que consiste a recuperar o sinal de saida de um aparelho, e a injéctà-lo em entrada atenuado e em oposição de fase (contra-fase), em relação à fase do sinal de entrada!...

Esta astucia, diminui o ganho dos amplificadores, aumenta a resposta em frequência e diminui drasticamente a distorsão (DHT),  tudo isto é mais ou menos eficaz, segundo a quantidade gobal de realimentação (quantidade aplicada em entrada), que se exprime em dB. Então, muita realimentação dà muito menos ganho, muita mais resposta em frequência e muito menos distorsão, Dà vontade de utilisar muito dito assim, mas como foi visto hà muitos problemas associados a isto...

Para resumir a diferença entre realimentação global e local, fiz um desenho. Como véem a global vai da saida até à entrada, ora que a local so engloba um andar isolado. Hà muito mais variantes de uma e outra, mas este é o modelo classico, e o mais utilisado !!!

Não hesitem, se téem duvidas !... e...    Até+

O problema da realimentação negativa, se não me engano, tem a ver com o desfasamento do sinal injectado em relação ao original, não é?
Qual é a vantagem de usar localmente em vez de global?
De que modo é que se controla a "quantidade" de realimentação negativa (sinal injectado?)?

R

Mais logo tenho que ir estudar outra vez o Sedra e Smith para perceber bem este tópico. Estou a gostar!

tfonseca escreveu:

Mais logo tenho que ir estudar outra vez o Sedra e Smith para perceber bem este tópico. Estou a gostar!

Eu nem estudando os Statler and Waldorf percebi patavina....
 

ricardo onga-ku escreveu:

O site da Elliott Sound tem alguma informação interessante sobre as diferentes características da amplificação a Válvulas e a Transístores.
Talvez o Paulo "td124" possa tecer alguns comentários.

[i][b]Valves vs. Transistors (Part I) - What are the differences?

...
(1)
It is critically important to understand that if two amplifiers sound different from each other (in a proper blind test), then one or both of them has a fault. There have been some extraordinarily good valve amps made, and without exception they are push-pull. Some of these amplifiers will be found to be virtually indistinguishable from a good transistor amp in a double-blind listening test. The extension of this is that if you can hear a difference between a valve amplifier (of any topology) and a good quality transistor amp, the valve amp is obviously making changes to the signal that the transistor amp is not.

...
(2)
The most common change is distortion, although frequency response is often wobbly if the amp's output impedance is non-zero. Frequency response is easily corrected with equalisation, but harmonic and intermodulation distortion cannot be undone with real-life circuits. While it might be possible with some extremely clever DSP (digital signal processor) programming, there are literally countless modern amplifiers available that already have distortion and intermodulation levels that are well below the threshold of audibility, with many close to the limits of measurement equipment.

l

The whole article is interesting but in the end primarily a rhetorical offense against valve amps. Technical facts are mixed up with bare and even false claims.

At first I didn't like the claim made in the first paragraph cited above: "It is critically important to understand that if two amplifiers sound different from each other (in a proper blind test), then one or both of them has a fault."
But consequently thought and applied it is true - to a certain degree.

But the second paragraph contains the misleading claim: "there are literally countless modern amplifiers available that already have distortion and intermodulation levels that are well below the threshold of audibility". In reality, almost all these amps sound different from each other and therefore are all (more ore less) faulty. I have the impression that the author wants to suggest that all modern transistor amps measure and sound more or less perfect. This is certainly not the case as these amps are not interchangeable in a hifi system without altering the sound. Otherwise the audio world would be simple, one could grab one of these "countless perfect" amps for a reasoable price and live happily ever after. That's simply a myth.

To complicate this topic even more it should be mentioned that today we have a 3rd category of amps, the switched or class-D amps.
Although these amps are faulty too, there are tiny and cheap boxes available which can perform shockingly good in certain aspects of sound.

Cheers
Manfred

Hi Manfred.

You summed it up quite well, couldn't agree more.

In response to Manfred, I think Paulo "td124" was trying to keep away from the transistor vs. tube debate (although he does claim tube superiority every other post  ) and actually his own designs combine both components or technologies.

I guess this topic is supposed to be more about the sonic 'properties' or 'atributes' of a valve amplifier, those that attract audiophiles into choosing one technology over the other and are the subject of such a passionate debate.

From where I stand, it doesn't makes much sense to approach sound characterization from a lyrical point of view, using 'imprecise' adjectives like "sweet", "gentle", "liquid", "rigorous", "punchy", etc. that have different meanings to different people to describe the (sonic) performance of an equipment or system.
What does "sweet" mean?
Is it good or bad?
I for one don't like sweets..."sweet" is not good.

I would rather know about channel separation, noise floor and dynamic ability, frequency range and balance, linearity and which components or topological decision of a certain design are afecting these properties in a negative or positive way.

I have a goal for my system: to be able to reproduce a recording as faithfully as possible so that, for instance, the sound of a piano recorded in and old library retains the sonic attributes of the instrument's timbre and the spatial atmosphere of the original event as much as the recording quality and stereo technology allows.

We cannot improve the sound quality of the recording, that's a fact; the recording is our weakest link, and all we can do is to polish a few rough edges on the worse ones.
The problem is that different recordings have different problems and if our "polish" is premanent then the good recordings will be negatively affected.
From this perspective, tone controls are in my view more adequate than permanent "colorations" or "vices" that one cannot use discriminately when necessary.

Cheers,
R

TD124 escreveu:

mannitheear escreveu:

ricardo onga-ku escreveu:

Valves vs. Transistors (Part I) - What are the differences?
...
(1) ... There have been some extraordinarily good valve amps made, and without exception they are push-pull ...
...
(2) ... Frequency response is easily corrected with equalisation, but harmonic and intermodulation distortion cannot be undone with real-life circuits ...
[/i]

The whole article is interesting but in the end primarily a rhetorical offense against valve amps. Technical facts are mixed up with bare and even false claims

In 1978, on a interview for the revue "l'Audiophile", Matti Otala (the father of the intermodulation distorsion says: At the present day, we know 20% about the audio objective/subjective unknowns!... so we have 80%, to discover and to work for, but the only way to progress, is to respect the things that we don't know!...
I think that many people speaks, and write about things they don't know!... and infortunately, they present them as évidences... poor cience, and poor audiophily, what we do on your name !!!

At first I didn't like the claim made in the first paragraph cited above: "It is critically important to understand that if two amplifiers sound different from each other (in a proper blind test), then one or both of them has a fault."
But consequently thought and applied it is true - to a certain degree.

As a designer, and as audiophile!... today there are two things that i'm really certain!!!...
1) If an amplifier is made with only science, it can not be bad!... but he may not sound excellent !!!...
2) If an amplifier is only made by ears, maybe will sound good!... and maybe also it measures bad !!!...
For me science is the land, and ears the threes... and one without other, are poor landscapes...

But the second paragraph contains the misleading claim: "there are literally countless modern amplifiers available that already have distortion and intermodulation levels that are well below the threshold of audibility". In reality, almost all these amps sound different from each other and therefore are all (more ore less) faulty. I have the impression that the author wants to suggest that all modern transistor amps measure and sound more or less perfect. This is certainly not the case as these amps are not interchangeable in a hifi system without altering the sound. Otherwise the audio world would be simple, one could grab one of these "countless perfect" amps for a reasoable price and live happily ever after. That's simply a myth.

A level of 0.003% of intermodulation distortion is already recognised by ear, and most of modern apparatus, have more than 0.1% of IMD or IIM, the tube amplifiers in average, have less than the transistors... but, anyway this not explains "all", the diferences, but they are facts...

To complicate this topic even more it should be mentioned that today we have a 3rd category of amps, the switched or class-D amps.
Although these amps are faulty too, there are tiny and cheap boxes available which can perform shockingly good in certain aspects of sound.

To complicate even more, we may talk about "true hybrids", that are a new group of amplifiers, with a pragmatic aproach, and about what, no one speaks !... Hifi is a passionate, but strange world, because most of people, even specialists, say what they think... and not what we would like to know!

Cheers
Manfred

Touché!
I agree with all you wrote.

As for your ''landscape with trees' analogy, I believe it is also valid if we wish to set up an accurate system and place it adequatelly in a room.

Cheers,
Ricardo

TD124 escreveu:

A level of 0.003% of intermodulation distortion is already recognised by ear, and most of modern apparatus, have more than 0.1% of IMD or IIM, the tube amplifiers in average, have less than the transistors... but, anyway this not explains "all", the diferences, but they are facts...

I don't understand this.
Are you saying that intermodulation distortion 'artifacts' at -90dB can be recognised by ear?  

How is that possible?
What is the noise floor of your source?
What is the noise floor of your amplifier?
What is the noise floor of your room?
Which recordings have more than 70dB of dynamic range to make this 0,003% meaningful?


One more thing: I have read in multiple sources that harmonic distortion produces intermodulation distortion.
Can you comment on that, s'il vous plaît?

R

TD124 escreveu:

33]To complicate even more, we may talk about "true hybrids", that are a new group of amplifiers, with a pragmatic aproach, and about what, no one speaks !... Hifi is a passionate, but strange world, because most of people, even specialists, say what they think... and not what we would like to know!

What is a "tue hybrid" if i may ask ?

ricardo onga-ku escreveu:

I have a goal for my system: to be able to reproduce a recording as faithfully as possible so that, for instance, the sound of a piano recorded in and old library retains the sonic attributes of the instrument's timbre and the spatial atmosphere of the original event as much as the recording quality and stereo technology allows.

Cheers,
R

Hello Ricardo,

you have clearly expressed the goal for your system. Please allow a few thoughts to this. For me, I wold see impregnable limits in this I call it "objective" approach. Unless one is a recording engineer, the listener never knows, how the original event sounded. And even if we would know how the original event should sound and that was actually captured by the microphones it is very likely that the sound was altered through the mixing, editing and mastering processes.
So the "original" that could be approached is in almost all cases not the musical event itself but only what the mastering engineer heard on the final stage of editing the recording. And that's even more unfamiliar.

For myself I follow a far more "subjective" approach. I try to voice my audio system in a way that it sounds " just right". And the "just right" should apply for solo violin, double bass and a capella voice just as well as for a church organ, full orchestra, heavy distorted rock guitar or a drum kit - or what else. I try to do this in a more and more "intuitive" and holistic rather than analytical way. If it sounds "right", that can be perceived immediadely, without need to be analyzed: the music speaks directly to the heart of the listener. If a new component is not compelling immediately with different kind of music, it is likely a step to the side than forwards and therefore uninteresting. For final confirmation in most cases a long time test is necessary anyway.

A true story: Werner (who has brought me to Tannoy) did make Rock and Heavy Metal (not my favourite genre btw.) recordings for himself. He discovered, that with Tannoy speakers he could reproduce the sound in the best possible way and used therefore the Glenair as a Monitor during the recording process. He said, that the very high degree of fidelity was not only given for amplified instruments like electic guitar and electric bass, but in the same way for all natural sounds they heard during the recording process, like the drum kit in the room, the vocals and so on.

Cheers
Manfred

Milton escreveu:

TD124 escreveu:

33]To complicate even more, we may talk about "true hybrids", that are a new group of amplifiers, with a pragmatic aproach, and about what, no one speaks !... Hifi is a passionate, but strange world, because most of people, even specialists, say what they think... and not what we would like to know!

What is a "tue hybrid" if i may ask ?

 
 
O F F        T O P I C!!!
 
 
Here is the perfect Hybrid
 
A  Mula / The Mule

Born from a male donkey and a mare ...
 

 
 

TD124 escreveu:

To complicate even more, we may talk about "true hybrids", that are a new group of amplifiers, with a pragmatic aproach, and about what, no one speaks !... Hifi is a passionate, but strange world, because most of people, even specialists, say what they think... and not what we would like to know!

Sounds interesting. I would be pleased to hearing more about that hybrid topology and your work, if that is possible.

Cheers
Manfred

Sorry, double post.

TD124 escreveu:

ricardo onga-ku escreveu:

TD124 escreveu:

A level of 0.003% of intermodulation distortion is already recognised by ear...quote]
I don't understand this.
Are you saying that intermodulation distortion 'artifacts' at -90dB can be recognised by ear?  

How is that possible?
What is the noise floor of your source?
What is the noise floor of your amplifier?
What is the noise floor of your room?
Which recordings have more than 70dB of dynamic range to make this 0,003% meaningful?


One more thing: I have read in multiple sources that harmonic distortion produces intermodulation distortion.
Can you comment on that, s'il vous plaît?

R

Intervista de Matti Otala na revista l'Audiophile de 1978!!!... e mais uma tradução...  

Os ultimos estudos efectuados por Matti Otala e os seus colaboradores no centro de pesquisa de Oulou na Finlândia, mostram que a DIT é reconhecivel a niveis de 0.003%! em escuta musical.
Este resultado foi obtido a partir de vàrios testes, tratados estatisticamente.
O limite é incrivelmente baixo, e é possivel que o seja ainda mais baixo, se feito a partir de testes adaptados. Em todos os casos, o nivel està situado a 90 dB mais baixo do que o sinal, o que quer dizer que os sinais de intermodulação são inferiores ao ruido térmico!...

Acho que chega como prova!... não ???????????????????????????

Mas se tivesses compreendido o que é a DIT, e a maneira como interaje com o sinal, não terias!  

Então vai ler o artigo do Pass, com atenção... pois ele explica tudo o senhor !!! 

  Abraço

Oh my god. I think I'm glad to be no audio engineer. It looks like solving an equation with far too many unknowns while walking on hands and applauding at the same time.  

A task for Chuck Norris, I guess. http://www.chucknorrisfacts.com/

In my personal view, and in relationship to the measurements made to amplifiers and what they stand for, I don’t think that they tell us the whole story. If we (for example) take the frequency range of a given amplifier (let’s say 20 to20.000), all we know is that this is the range the amplifier is capable of. But does it tell us anything about the “quality” (in the sense of realism) of the bass or of the high frequencies? Does it tell you anything about the separation between instruments and soundstage? Do we find out by measuring, if it reproduces the right tone of an instrument? I think that measurements are important, but they are definitely not the whole story, there is more to it. And probably, they could be misleading for those who rely only on measurements to assess the sound quality of an amplifier, because the truth is that they tell as a lot and at the same time, nothing at all.

reirato escreveu:

Milton escreveu:

TD124 escreveu:

33]To complicate even more, we may talk about "true hybrids", that are a new group of amplifiers, with a pragmatic aproach, and about what, no one speaks !... Hifi is a passionate, but strange world, because most of people, even specialists, say what they think... and not what we would like to know!

What is a "tue hybrid" if i may ask ?

 
 
O F F        T O P I C!!!
 
 
Here is the perfect Hybrid
 
A  Mula / The Mule

Born from a male donkey and a mare ...
 

 
 

You are right Reirato !!!, because like the Mule's, the "true hybrids", don't seem to make baby's !!! 

And now more seriously!... Well the term "true or fake hybrid", is an ironical expression that i've created to separate the commercial apparatus using valves & transistors, from the apparatus where all the circuitry is both tecnology mixed!... and i'm going to explained that:

Today, and in the past, most of hybrid amplifiers were just the summ, of a valve stage with a transistor stage, what in fact is the same thing than, have a valve préamplifier with a transistor power amplifier. For me (even if somethimes this work very good), its just a mix of colors, and does not go further. That's what i call, a "fake hybrid"!!! i know it's not gentle... but is only ironic!  

On the other hand, he have some apparatus where the valves & transistors are mixed on the same stage, which one at a place were he is Superior to the other. We are going to use the transistor were he is the best, and the same with the valves!... and in that case the performances are much higher, than the summ of both!... and in that case i'm in face of a "true hybrid", but once again is just IRONY !!!

We must decide the language of the topic, or... je commençe à parler français, d'accord ???  

mannitheear escreveu:

ricardo onga-ku escreveu:

I have a goal for my system: to be able to reproduce a recording as faithfully as possible so that, for instance, the sound of a piano recorded in and old library retains the sonic attributes of the instrument's timbre and the spatial atmosphere of the original event as much as the recording quality and stereo technology allows.

Cheers,
R

Hello Ricardo,

you have clearly expressed the goal for your system. Please allow a few thoughts to this. For me, I wold see impregnable limits in this I call it "objective" approach. Unless one is a recording engineer, the listener never knows, how the original event sounded. And even if we would know how the original event should sound and that was actually captured by the microphones it is very likely that the sound was altered through the mixing, editing and mastering processes.
So the "original" that could be approached is in almost all cases not the musical event itself but only what the mastering engineer heard on the final stage of editing the recording. And that's even more unfamiliar.

For myself I follow a far more "subjective" approach. I try to voice my audio system in a way that it sounds " just right". And the "just right" should apply for solo violin, double bass and a capella voice just as well as for a church organ, full orchestra, heavy distorted rock guitar or a drum kit - or what else. I try to do this in a more and more "intuitive" and holistic rather than analytical way. If it sounds "right", that can be perceived immediadely, without need to be analyzed: the music speaks directly to the heart of the listener. If a new component is not compelling immediately with different kind of music, it is likely a step to the side than forwards and therefore uninteresting. For final confirmation in most cases a long time test is necessary anyway.

A true story: Werner (who has brought me to Tannoy) did make Rock and Heavy Metal (not my favourite genre btw.) recordings for himself. He discovered, that with Tannoy speakers he could reproduce the sound in the best possible way and used therefore the Glenair as a Monitor during the recording process. He said, that the very high degree of fidelity was not only given for amplified instruments like electic guitar and electric bass, but in the same way for all natural sounds they heard during the recording process, like the drum kit in the room, the vocals and so on.

Cheers
Manfred

Hello Manfred,

It is my firm belief that, unlike pop/rock, the reproduction of acoustic unamplified music played in a natural acoustic environment requires the highest possible accuracy; only then can you achieve to produce a reasonably convincing illusion.
I think that at least the early technological advances in recording and domestic reproduction had a goal: the quest for high fidelity reproduction of "classical" music, a hard task if we take into account that an orquestra can have as many as one hundred players and sometimes a chorus.
Later, when domestic reproduction became accessible to all and even portable, the recording industry redirected it's priorities to where there was money to be made: popular music (rock/pop/etc.).

I think that rock/pop doesn't require as much accuracy because most of it uses amplified and electronic instruments, recorded in a quasi-anechoic space or straight to the computer/mixing console and the final product — music — is not the recording of a single (different dates or even different cites are common) live event and the spatial cues do not originate from a real space.
The final product is the result of a creative mixing and manipulating process where the original sounds of the vocals and instruments are gathered and transformed into a different entity.
Besides, pop/rock recordings don't always use state-of-the-art recording gear, the producers are not very demanding when it comes to sound quality and the close-micing techniques used in studios afect timbre and "naturalness".


Anyway, if we were not present at the original event (a concert or a studio multi-session), a recording or an FM broadcast is the closest we'll ever get to it.


This leaves us with two options: either we try to reproduce the recorded signal as faithfully as we possibly can or we can "tailor" the sound to our taste which doesn't take us closer to the sound of the original event but may very well make the listening experience more "compelling".

From my experience, "tailoring" is not free of adverse side-effects...
And although I could bear living with (very) mildly "voiced" electronics, the "sonic imprint" of strong-flavoured gear such the 47Lab electronics that I once owned or the Audio Note UK gear I heard is just to self-imposing and for me it not only reduces the lisening pleasure but it also afects the ilusion that real instruments are being played.

But when it comes to loudspeakers, by far the most imperfect of the system's components, I agree that one does have to choose a bit to taste because every speaker design consists of a few compromises.

R

mannitheear escreveu:

...
Oh my god. I think I'm glad to be no audio engineer. It looks like solving an equation with far too many unknowns while walking on hands and applauding at the same time.  

A task for Chuck Norris, I guess. http://www.chucknorrisfacts.com/

I Manfred,

i don't think so!... When we see from the outside, it seems that audio world is a battle for life, and no one respect the other,... each one walking in is own direction !!!... sure of his own opinions and certitudes!...

But, from the inside the things are changing,... and everybody feels today, that we need to change a lot of things,... to bring the relationship between subjective & objective, to a real first priority on audio!!!... and this envolves on designing, fabrication and communication etc...

We have seeds and flowers,... but we still need water, a lot of water... and that's the battle today !!!

Cheers

ricardo onga-ku escreveu:

In response to Manfred, I think Paulo "td124" was trying to keep away from the transistor vs. tube debate (although he does claim tube superiority every other post  ) ...

Cheers,
R

Hi, what are you trying to say ???

I've a preference (personal) for tubes is true!... but i've never claimed they are superior (as audio device),... when i say that tubes are far more linear than transistor... i'm talking about the component, not the amplifiers !!!... and i've never said that valve is superior than transistor*!... I'm a transistor fan !!! 

Cheers
*... but in fact it is !!!!

I also think that SS is superior, and I don't mind others to own them.

TD124 escreveu:

ricardo onga-ku escreveu:

A level of 0.003% of intermodulation distortion is already recognised by ear...quote]
I don't understand this.
Are you saying that intermodulation distortion 'artifacts' at -90dB can be recognised by ear?  

How is that possible?
What is the noise floor of your source?
What is the noise floor of your amplifier?
What is the noise floor of your room?
Which recordings have more than 70dB of dynamic range to make this 0,003% meaningful?


One more thing: I have read in multiple sources that harmonic distortion produces intermodulation distortion.
Can you comment on that, s'il vous plaît?

R

Intervista de Matti Otala na revista l'Audiophile de 1978!!!... e mais uma tradução...  

Os ultimos estudos efectuados por Matti Otala e os seus colaboradores no centro de pesquisa de Oulou na Finlândia, mostram que a DIT é reconhecivel a niveis de 0.003%! em escuta musical.
Este resultado foi obtido a partir de vàrios testes, tratados estatisticamente.
O limite é incrivelmente baixo, e é possivel que o seja ainda mais baixo, se feito a partir de testes adaptados. Em todos os casos, o nivel està situado a 90 dB mais baixo do que o sinal, o que quer dizer que os sinais de intermodulação são inferiores ao ruido térmico!...

Acho que chega como prova!... não ???????????????????????????

Mas se tivesses compreendido o que é a DIT, e a maneira como interaje com o sinal, não terias!  

Então vai ler o artigo do Pass, com atenção... pois ele explica tudo o senhor !!! 

  Abraço

Como não confio muito em traduções procurei pelo artigo original mas apenas o encontro no site da AES.
Infelizmente não estou inscrito mas copiei o abstract:

Psychoacoustic Detection Threshold of Transient Intermodulation Distortion
Petri-Larmi, Margit; Otala, Matti; Lammasniemi, Jorma

The audible threshold of transient intermodulation distortion (TIM) was determined for the six most sensitive subjects of the previously reported test series of 68 listeners. Improved equipment, carefully controlled listening environment, a digital TIM generator, and five recorded stereophonic music samples were used. The results show that in certain types and passages of music, a trained and sensitive listener can reliably detect extremely low values of distortion. Low distortion values were perceived only as changes in the sound character, and not as distortion.

As partes que acentuei parecem-me importantes: em certos tipos de música e quando a intensidade é baixa o TIM é percepcionado como uma mudança de tonalidade e não como distorção.

R

TD124 escreveu:

ricardo onga-ku escreveu:

In response to Manfred, I think Paulo "td124" was trying to keep away from the transistor vs. tube debate (although he does claim tube superiority every other post  ) ...

Cheers,
R

Hi, what are you trying to say ???

I've a preference (personal) for tubes is true!... but i've never claimed they are superior (as audio device),... when i say that tubes are far more linear than transistor... i'm talking about the component, not the amplifiers !!!... and i've never said that valve is superior than transistor*!... I'm a transistor fan !!! 

Cheers
*... but in fact it is !!!!

Christ, you'll be crucified for that.

R

António José da Silva escreveu:

I also think that SS is superior, and I don't mind others to own them.

No more!!!... Valve is music, life, wine, sun, love and all the best things of life!!!... transistor its just the opposite,... but is good also... the proof is that are people that owns them!!!... so  

Até+

António José da Silva escreveu:

In my personal view, and in relationship to the measurements made to amplifiers and what they stand for, I don’t think that they tell us the whole story. If we (for example) take the frequency range of a given amplifier (let’s say 20 to20.000), all we know is that this is the range the amplifier is capable of. But does it tell us anything about the “quality” (in the sense of realism) of the bass or of the high frequencies? Does it tell you anything about the separation between instruments and soundstage? Do we find out by measuring, if it reproduces the right tone of an instrument? I think that measurements are important, but they are definitely not the whole story, there is more to it. And probably, they could be misleading for those who rely only on measurements to assess the sound quality of an amplifier, because the truth is that they tell as a lot and at the same time, nothing at all.

Horses for courses comes to mind.
And since each measurement focuses on a single parameter, you cannot expect a frequency response measurement to inform you about channel separation or jitter or cabinet resonances or intermodulation distortion...you'll have to measure each of these separately.

As for "realism" or "the right tone", these are attributes of the recording and it's obvious that a more "transparent" (or hi-fi) amplifier will produce a more "realistic" sound or "a righter tone".

The same is true for a TV:


R

ricardo onga-ku escreveu:

TD124 escreveu:

...I'm a transistor fan !!! 

Cheers

Christ, you'll be crucified for that.

R

No, it's true !!!...

I've made a transistor amplifier once!... but he never worked well!... at first, i was persuaded, that i've made something wrong, so i decided to tweek it... and at last i've understood the problem!...

It's impossible to make something convenient with that component !... but i love it, is so cute ! 

Cheers

ricardo onga-ku escreveu:

António José da Silva escreveu:

In my personal view, and in relationship to the measurements made to amplifiers and what they stand for, I don’t think that they tell us the whole story. If we (for example) take the frequency range of a given amplifier (let’s say 20 to20.000), all we know is that this is the range the amplifier is capable of. But does it tell us anything about the “quality” (in the sense of realism) of the bass or of the high frequencies? Does it tell you anything about the separation between instruments and soundstage? Do we find out by measuring, if it reproduces the right tone of an instrument? I think that measurements are important, but they are definitely not the whole story, there is more to it. And probably, they could be misleading for those who rely only on measurements to assess the sound quality of an amplifier, because the truth is that they tell as a lot and at the same time, nothing at all.

Horses for courses comes to mind.
And since each measurement focuses on a single parameter, you cannot expect a frequency response measurement to inform you about channel separation or jitter or cabinet resonances or intermodulation distortion...you'll have to measure each of these separately.

As for "realism" or "the right tone", these are attributes of the recording and it's obvious that a more "transparent" (or hi-fi) amplifier will produce a more "realistic" sound or "a righter tone".

The same is true for a TV:

R

Frequency response was just one example I used, because even all the other measurements that are done today, will not tell us anything about the things I stated above. Maybe one day when engineers find a way to measure real music instead of test tones.

TD124 escreveu:

No, it's true !!!...

I've made a transistor amplifier once!... but he never worked well!... at first, i was persuaded, that i've made something wrong, so i decided to tweek it... and at last i've understood the problem!...

It's impossible to make something convenient with that component !... but i love it, is so cute ! 

Cheers

 

António José da Silva escreveu:

ricardo onga-ku escreveu:

António José da Silva escreveu:

In my personal view, and in relationship to the measurements made to amplifiers and what they stand for, I don’t think that they tell us the whole story. If we (for example) take the frequency range of a given amplifier (let’s say 20 to20.000), all we know is that this is the range the amplifier is capable of. But does it tell us anything about the “quality” (in the sense of realism) of the bass or of the high frequencies? Does it tell you anything about the separation between instruments and soundstage? Do we find out by measuring, if it reproduces the right tone of an instrument? I think that measurements are important, but they are definitely not the whole story, there is more to it. And probably, they could be misleading for those who rely only on measurements to assess the sound quality of an amplifier, because the truth is that they tell as a lot and at the same time, nothing at all.

Horses for courses comes to mind.
And since each measurement focuses on a single parameter, you cannot expect a frequency response measurement to inform you about channel separation or jitter or cabinet resonances or intermodulation distortion...you'll have to measure each of these separately.

As for "realism" or "the right tone", these are attributes of the recording and it's obvious that a more "transparent" (or hi-fi) amplifier will produce a more "realistic" sound or "a righter tone".

The same is true for a TV:

R

Frequency response was just one example I used, because even all the other measurements that are done today, will not tell us anything about the things I stated above. Maybe one day when engineers find a way to measure real music instead of test tones.

The things you stated above, "realism", "separation between instruments and soundstage", "the right tone of an instrument", are not as attributes of your gear but of the recording.

You can only hear them if they are part of the recording.

And to accurately reproduce the recording you'll need "transparent" gear.


Imagine you are looking through a pair of binoculars: do you have any doubts that the most accurate lenses would give you a more realistic image?

And lens accuracy can be measured.

Measurements exist for a reason, they quantify parameters that are part of the performance.

R

ricardo onga-ku escreveu:

You can only hear them if they are part of the recording.

The same recording gets presented differently through different amplifiers (or any other gear) even when they measure identically. This is a undeniable fact.

There are some differences that cannot be readily explained. An amp that is deemed "identical" to another in a test situation, may sound completely different in a normal listening environment. It is these differences that are the hardest to deal with, since we do not always measure some of the things that can have a big influence on the sound.


http://www.audioholics.com/audio-amplifier/the-sound-of-an-amplifier



O que nos vale, é que para além das medicoes, ainda temos os ouvidos e o nosso gosto pessoal (e livre arbítrio) para podermos decidir o que nós achamos que nos soa mais parecido com o real, ou a ilusão do real.

António José da Silva escreveu:

There are some differences that cannot be readily explained. An amp that is deemed "identical" to another in a test situation, may sound completely different in a normal listening environment. It is these differences that are the hardest to deal with, since we do not always measure some of the things that can have a big influence on the sound.


http://www.audioholics.com/audio-amplifier/the-sound-of-an-amplifier



O que nos vale, é que para além das medicoes, ainda temos os ouvidos e o nosso gosto pessoal (e livre arbítrio) para podermos decidir o que nós achamos que nos soa mais parecido com o real, ou a ilusão do real.

Aconselho a leitura do link que indiquei, pois é bastante interessante e poe alguma luz sobre este assunto que é mais escuro do que muitos parecem querer admitir.



We can (almost) rule out distortion as a factor in this equation, since amps with comparatively high distortion can be comparable to others with negligible distortion. One major difference is that typical single ended triode amplifiers have quite high levels of low order even harmonics. Although these will give the sound a unique character, I doubt that this is the sole reason for the perceived high frequency performance - I could also be wrong.

ricardo onga-ku escreveu:

...
Psychoacoustic Detection Threshold of Transient Intermodulation Distortion
Petri-Larmi, Margit; Otala, Matti; Lammasniemi, Jorma

The audible threshold of transient intermodulation distortion (TIM) was determined for the six most sensitive subjects of the previously reported test series of 68 listeners. Improved equipment, carefully controlled listening environment, a digital TIM generator, and five recorded stereophonic music samples were used. The results show that in certain types and passages of music, a trained and sensitive listener can reliably detect extremely low values of distortion. Low distortion values were perceived only as changes in the sound character, and not as distortion.

As partes que acentuei parecem-me importantes: em certos tipos de música e quando a intensidade é baixa o TIM é percepcionado como uma mudança de tonalidade e não como distorção.

R

???... o que é que o bonequinho quer dizer ?... queres concluir o quê ???...

Os 5% de um SE 300B da Anzai Zaïka ou de um Western Electric 91A,... também não se entendem como sendo da distorção... mas como sendo beleza, para a maioria de aqueles que os escutaram. De um lado 5% de DHT e do outro 0.003% de DIT, que se sigo bem o teu raciocinio... são apenas percepcionados como um mudança de tonalidade !!!...

Lembro-te que a noção de distorção é: ... toda alteração involuntària do sinal original!...   ... e isto é vàlido, que essa alteração, seja grande, pequena, feia, bonita, audivel ou inaudivel !!!... não ?

E agora a escolher!... entre DHT e DIT, qual deciderias de eliminar em primeiro ???...

Até+

ricardo onga-ku escreveu:

...
I guess this topic is supposed to be more about the sonic 'properties' or 'atributes' of a valve amplifier, those that attract audiophiles into choosing one technology over the other and are the subject of such a passionate debate.
...

Cheers,
R

È verdade que este topico partiu a 100 à hora, sem dar mesmo a possibilidade de determinar os limites do sujeito e a intenção inicial. Mas o nivel de participação e a rapidez com que se fez, mostra que à um interesse a abordar esta~questão que é: Qual a razão, ou razões de tantas diferenças à escuta de um aparelho!...

È evidente que nunca foi questão para mim de transformar este topico, ou de construi-lo..., sobre a base do debate vàlvula vs transistor e isto por duas razões:
1) Este debate não conduz a parte alguma, e se as duas tecnologias coabitam ainda e sempre!... é que nenhuma delas não atingiu a universalidade...
2) Ao contàrio do que possam pensar (pelas frases ironicas), gosto do transistor e reconhêço-lhe certas qualidades, inexistentes na vàlvulas!... explicando que desde hà 15 anos o meu trabalho, està baseado na dosagem destas duas tecnologias... afim de (esperar) encontrar um som mais proximo do original !.

Na realidade este topico deveria ser um espaço aonde abordariamos, as diferentes sonoridades e (eventuais) desviações do som das vàlvulas, que partilham os amadores. Evidentemente um topico gémeo poderia ser feito para os transistores, colunas, gira-discos etc... pois cada mundo tecnologico possede as suas qualidades e perversões!... mas, estou contente que este tema corresponda à vontade geral de aprofundir o tema da escuta, então ele evoluirà nesse sentido, e/ou outro que nos toque !...

Até+

Eu apenas vou acrescentar uma questão que se baseia na experiência audiófila no passado até aos nossos dias e que representará toda a experiência acumulada até hoje ou de forma geral o bom senso gerado até então:

Que tipo de amplificador ( transistores ou Valvulas) é mais usado no mundo mais experimentado da audiófilía ?

Pelo menos para mim a resposta a esta questão vai certamente iluminar as minhas duvidas e tenho a certeza que será bem respondida... 

BAILOTE escreveu:

Eu apenas vou acrescentar uma questão que se baseia na experiência audiófila no passado até aos nossos dias e que representará toda a experiência acumulada até hoje ou de forma geral o bom senso gerado até então:

Que tipo de amplificador ( transistores ou Valvulas) é mais usado no mundo mais experimentado da audiófilía ?

Pelo menos para mim a resposta a esta questão vai certamente iluminar as minhas duvidas e tenho a certeza que será bem respondida... 

Olà Bailote,

a resposta não é simples, pois seria necessàrio determinar o sentido de "mundo mais experimentado"!... e na realidade cada mercado (Paìs) não reaje da mesma maneira, então assim de repente eu diria em tendo em consideração, os elementos de venda em High-End:

Estados Unidos : Igualdade entre transistor e vàlvula
Canadà : Transistor predominante
UK : Transistor predominante
França : Igualdade entre transistor e vàlvula
Alemanha : Transistor predominante
Japão : Vàlvula predominante
Norte da Europa/Escandinàvia : Transistor predominante
Sul da Europa/Mediterrâneo : Vàlvula predominante

isto são, em grosso, as informações de 2012 em meu poder, sobre a venda de High-End novo, mas deve dar para se fazer uma ideia, que a "mainstream tecnologica" não é em nenhum dos campos!...

Até+

A Filosofia dos construtores:

Esta frase de aparência complicada é na realidade um facto real e muito simples. A filosofia de um construtor, é o grupo de ideias, convições e duvidas, que o conduzem a fazer um escolha técnica bem determinada, no lugar de outra. È evidente que essa escolha, vai determinar de uma maneira importante o som dos aparelho. As escolhas são tantas, e às vezes tão complexas, que na realidade os construtores nunca fazem exactamente as mesmas,... o que alimenta ainda mais as diferenças!...

Mas quando se olha para isto com uma visão distanciada, vê-se que fundamentalmente existem dois grupos no que diz respeito à concepção de um aparelho. Certos construtores defendem mesmo, não possuir filosofia propria, mas quando se analisa o conjunto das escolhas, apareçe claramente a adesão a um ou outro campo (mesmo inconsciente). isto não quer dizer que de vês em quando "não se faça um entorse à regra", indo buscar uma ideia do outro lado, mas é algo de singular e não uma regra geral. Os dois grandes grupos são:

Os construtores audiofilos : Estes construtores partem do principio que tudo jà foi inventado, mas que se pode ainda amelhorar o desempenho e/ou a escuta. A partir desta ideia eles escolhem um circuito de alto nivel "classico", pessoal ou inspirado de outros, e vão graças à evolução dos componentes e outros elementos, amelhorà-lo até que ele corresponda ao nivel de exigência deles. Com o tempo o aparelho vai evoluir e se amelhorar, dando o sentimento que esta evolução é inesgotàvel. Visto assim estes aparelhos são um "work on progress", no qual os fundamentos técnico são estàveis, mas os elementos de constituição em evolução permanente...
Ex: de construtores audiofilos: Luxman, Conrad Johnson, Jadis, Air Tight, e mesmo Naim!, etc...
Principais avantagens : Perpétuidade de uma reprodução sonora homogenea...
Principais desavantagens : Impossibilidade de ultrapassar muito os limites naturais do circuito...

Os construtores técnologicos : Neste caso a direção é oposta, e estes ultimos consideram que a unica maneira de evoluir, passa pela criação de novos circuitos, permitindo de abrir horizontes ainda não explorados. Os aparelhos tomam assim direções técnicas originais e singulares, afim de corresponder à ideia de evolução. As escolhas são ditadas pela técnica, mas igualmente pelo desejo de atingir um "novo som", mais universal!...
Ex: de construtores técnologicos : Audio Research, Lamm, BAT, Aesthetix, e mesmo Quad!, etc...
Principais avantagens : Possibilidade de atingir grandes desempenhos e sonoridade...
Principais desavantagens : Dificuldade a garantir uma escuta homogenea entre aparelhos...

Acho que esta intervenção abre um pouco o debate, e leva-nos para àguas mais concretas!...

Até+

TD124 escreveu:

A Filosofia dos construtores:

Esta frase de aparência complicada é na realidade um facto real e muito simples. A filosofia de um construtor, é o grupo de ideias, convições e duvidas, que o conduzem a fazer um escolha técnica bem determinada, no lugar de outra. È evidente que essa escolha, vai determinar de uma maneira importante o som dos aparelho. As escolhas são tantas, e às vezes tão complexas, que na realidade os construtores nunca fazem exactamente as mesmas,... o que alimenta ainda mais as diferenças!...

Mas quando se olha para isto com uma visão distanciada, vê-se que fundamentalmente existem dois grupos no que diz respeito à concepção de um aparelho. Certos construtores defendem mesmo, não possuir filosofia propria, mas quando se analisa o conjunto das escolhas, apareçe claramente a adesão a um ou outro campo (mesmo inconsciente). isto não quer dizer que de vês em quando "não se faça um entorse à regra", indo buscar uma ideia do outro lado, mas é algo de singular e não uma regra geral. Os dois grandes grupos são:

Os construtores audiofilos : Estes construtores partem do principio que tudo jà foi inventado, mas que se pode ainda amelhorar o desempenho e/ou a escuta. A partir desta ideia eles escolhem um circuito de alto nivel "classico", pessoal ou inspirado de outros, e vão graças à evolução dos componentes e outros elementos, amelhorà-lo até que ele corresponda ao nivel de exigência deles. Com o tempo o aparelho vai evoluir e se amelhorar, dando o sentimento que esta evolução é inesgotàvel. Visto assim estes aparelhos são um "work on progress", no qual os fundamentos técnico são estàveis, mas os elementos de constituição em evolução permanente...
Ex: de construtores audiofilos: Luxman, Conrad Johnson, Jadis, Air Tight, e mesmo Naim!, etc...
Principais avantagens : Perpétuidade de uma reprodução sonora homogenea...
Principais desavantagens : Impossibilidade de ultrapassar muito os limites naturais do circuito...

Os construtores técnologicos : Neste caso a direção é oposta, e estes ultimos consideram que a unica maneira de evoluir, passa pela criação de novos circuitos, permitindo de abrir horizontes ainda não explorados. Os aparelhos tomam assim direções técnicas originais e singulares, afim de corresponder à ideia de evolução. As escolhas são ditadas pela técnica, mas igualmente pelo desejo de atingir um "novo som", mais universal!...
Ex: de construtores técnologicos : Audio Research, Lamm, BAT, Aesthetix, e mesmo Quad!, etc...
Principais avantagens : Possibilidade de atingir grandes desempenhos e sonoridade...
Principais desavantagens : Dificuldade a garantir uma escuta homogenea entre aparelhos...

Acho que esta intervenção abre um pouco o debate, e leva-nos para àguas mais concretas!...

Até+

Obrigado Mestre eu tambem concordo que apesar da coisa parecer empatada tambem depende de fatores criteriosos diferentes que dificulta uma conclusão acertiva, no entanto leva-nos a definir com o tempo as nossas ideias pessoais e abrir a discussão num sentido mais lacto... 

 
Continuando com o prazer de ler e "ouvir"...será "ouler" 
Um obrigado especial para o Paulo (TD124) e para o Ricardo, continuem...
 

TD124 escreveu:

A Filosofia dos construtores:

Esta frase de aparência complicada é na realidade um facto real e muito simples. A filosofia de um construtor, é o grupo de ideias, convições e duvidas, que o conduzem a fazer um escolha técnica bem determinada, no lugar de outra. È evidente que essa escolha, vai determinar de uma maneira importante o som dos aparelho. As escolhas são tantas, e às vezes tão complexas, que na realidade os construtores nunca fazem exactamente as mesmas,... o que alimenta ainda mais as diferenças!...

Mas quando se olha para isto com uma visão distanciada, vê-se que fundamentalmente existem dois grupos no que diz respeito à concepção de um aparelho. Certos construtores defendem mesmo, não possuir filosofia propria, mas quando se analisa o conjunto das escolhas, apareçe claramente a adesão a um ou outro campo (mesmo inconsciente). isto não quer dizer que de vês em quando "não se faça um entorse à regra", indo buscar uma ideia do outro lado, mas é algo de singular e não uma regra geral. Os dois grandes grupos são:

Os construtores audiofilos : Estes construtores partem do principio que tudo jà foi inventado, mas que se pode ainda amelhorar o desempenho e/ou a escuta. A partir desta ideia eles escolhem um circuito de alto nivel "classico", pessoal ou inspirado de outros, e vão graças à evolução dos componentes e outros elementos, amelhorà-lo até que ele corresponda ao nivel de exigência deles. Com o tempo o aparelho vai evoluir e se amelhorar, dando o sentimento que esta evolução é inesgotàvel. Visto assim estes aparelhos são um "work on progress", no qual os fundamentos técnico são estàveis, mas os elementos de constituição em evolução permanente...
Ex: de construtores audiofilos: Luxman, Conrad Johnson, Jadis, Air Tight, e mesmo Naim!, etc...
Principais avantagens : Perpétuidade de uma reprodução sonora homogenea...
Principais desavantagens : Impossibilidade de ultrapassar muito os limites naturais do circuito...

Os construtores técnologicos : Neste caso a direção é oposta, e estes ultimos consideram que a unica maneira de evoluir, passa pela criação de novos circuitos, permitindo de abrir horizontes ainda não explorados. Os aparelhos tomam assim direções técnicas originais e singulares, afim de corresponder à ideia de evolução. As escolhas são ditadas pela técnica, mas igualmente pelo desejo de atingir um "novo som", mais universal!...
Ex: de construtores técnologicos : Audio Research, Lamm, BAT, Aesthetix, e mesmo Quad!, etc...
Principais avantagens : Possibilidade de atingir grandes desempenhos e sonoridade...
Principais desavantagens : Dificuldade a garantir uma escuta homogenea entre aparelhos...

Acho que esta intervenção abre um pouco o debate, e leva-nos para àguas mais concretas!...

Até+

Olhando para ambas as filosofias sem preconceitos, penso que se pode dizer que seguindo qualquer uma delas se podem obter excelentes resultados e que talvez (e se possível), a virtude esteja algures no meio.
Dito isto, quero dizer que também acho que muitos dos que seguem a primeira das duas variantes, conhecem perfeitamente o que se passa na segunda e provavelmente, vice versa.

António José da Silva escreveu:

TD124 escreveu:

A Filosofia dos construtores:
...
Os construtores audiofilos : Estes construtores partem do principio que tudo jà foi inventado, mas que se pode ainda amelhorar o desempenho e/ou a escuta. ...

Os construtores técnologicos : Neste caso a direção é oposta, e estes ultimos consideram que a unica maneira de evoluir, passa pela criação de novos circuitos, permitindo de abrir horizontes ainda não explorados. ...
...
Até+

Olhando para ambas as filosofias sem preconceitos, penso que se pode dizer que seguindo qualquer uma delas se podem obter excelentes resultados e que talvez (e se possível), a virtude esteja algures no meio.
Dito isto, quero dizer que também acho que muitos dos que seguem a primeira das duas variantes, conhecem perfeitamente o que se passa na segunda e provavelmente, vice versa.

Efectivamente quando não hà preconceitos, as duas pareçem complementares e ambas fazem sentido. mas o preconçeito é a base de uma filosofia... então a união das duas torna-se dificil, como se vê na realidade... e concrétamente elas são dificeis a conjugar...

Se analisar-mos um Single ended da Luxman e um da Lamm, vamos rapidamente ver que quase tudo os opõem, mesmo se ambos são excelentes aparelhos... no campo de excelência de um e de outro!...

Certas pessoas podem achar um anacronismo, que dois aparelhos tenham uma personalidade oposta, e que ao mesmo tempo sejam igualmente fiéis... ora uma analise "objectiva" à escuta, prova que muitas vezes esta situação é real. Este equilibrio que alguns chamam "equilibrio tonal", ora que na realidade deveria ser chamado "equilibrio de forma", é a base das escolas de escuta... e um aparelho com uma escuta "inglesa", "françesa" ou "americana" (as três principais escolas), podem ser équivalentes em fidelidade, mas apresentando escutas com aparências muito distantes... na aparência "subjectiva"!!!...

Digam do vosso pensar sobre tudo isto !...

Até+

TD124 escreveu:

Se analisar-mos um Single ended da Luxman e um da Lamm, vamos rapidamente ver que quase tudo os opõem, mesmo se ambos são excelentes aparelhos... no campo de excelência de um e de outro!...

Quais são esses campos de excelência?
Sei que o Lamm tem um bom desempenho mas o Luxman...

R

ricardo onga-ku escreveu:

TD124 escreveu:

Se analisar-mos um Single ended da Luxman e um da Lamm, vamos rapidamente ver que quase tudo os opõem, mesmo se ambos são excelentes aparelhos... no campo de excelência de um e de outro!...

Quais são esses campos de excelência?
Sei que o Lamm tem um bom desempenho mas o Luxman...

R

Jà esqueçestes as aulas que eu dava hà anos!... do outro lado!!!...  sublinhei certos pontos !!!

Power suply EU guidelines.

Na EU todas as "power supply" tem que ser do genero "switching power suply".

As da Conrad Johnson são todas linear power suplies.

Não acham que este pequeno pormenor não faz diferença na redução da distorção ?
http://en.wikipedia.org/wiki/Switched-mode_power_supply

afonso escreveu:

Power suply EU guidelines.

Na EU todas as "power supply" tem que ser do genero "switching power suply".

As da Conrad Johnson são todas linear power suplies.

Não acham que este pequeno pormenor não faz diferença na redução da distorção ?
http://en.wikipedia.org/wiki/Switched-mode_power_supply

Poderá ter alguma influencia, não sei, mas de toda a maneira, seja o que for que um aparelho medir, a fonte já está incluída.