Tell me what these spec's mean to me

[Mark4583]

I am trying to decide between two CD players, the NAD C521BEE and the C542 which is about $200.00 more.
From comparing the spec and features of the 2, besides outputs and inputs, and one haveing 12 volt trigger and HDCD there much the same except the C542 has-
Nichion "MUSE" Capacitor's, does not say if the C521BEE has or not, Make a diffrence or not?
The output impedence is 150 ohms compared to 300 ohms on the BEE, a noticable diffrence?
Thats about all that I see on the sheets that are diffrent besides the Display.
Based on this would it be a better performing unit?
Thanks

[woodman]

I am trying to decide between two CD players, the NAD C521BEE and the C542 which is about $200.00 more.
From comparing the spec and features of the 2, besides outputs and inputs, and one haveing 12 volt trigger and HDCD there much the same except the C542 has-
Nichion "MUSE" Capacitor's, does not say if the C521BEE has or not, Make a diffrence or not?
The output impedence is 150 ohms compared to 300 ohms on the BEE, a noticable diffrence?
Thats about all that I see on the sheets that are diffrent besides the Display.
Based on this would it be a better performing unit?
Thanks

No, these "specs" have virtually no meaning at all in terms of "better" performance. But I have two questions for you:

1. What are you going to be "feeding" the output of the CD player into?

2. Why have you narrowed your choices down to two units - both from NAD? Have you been taken in by their marketing hype - which leaves me so totally turned off that I wouldn't consider buying a NAD product ever, at any price? They violate a cardinal rule in business that says - " ... whatever you do, you do NOT "knock" or denigrate your competition".

There are a raft of competing models from which to choose from the likes of Denon, Marantz, Onkyo, Sherwood, and Yamaha. Nearly all sell for approx. the same price (or less) as the NADs and most of them weighing more than the two NADs (which both weigh in at a measly 9 lbs.). In an electro-mechanical device such as a CD player, a DVD player, a VCR, or a cassette deck, weight is a good indicator of how substantial is the "build quality".

Hope this helps you

[Mark4583]

well its realy between the Nad's or the Azur's 640A and 640C, and there within my price range and I see many positive reviews for both setups, ive looked at many others and these are what I like.

[E-Stat]

I am trying to decide between two CD players, the NAD C521BEE and the C542 which is about $200.00 more.
From comparing the spec and features of the 2, besides outputs and inputs, and one haveing 12 volt trigger and HDCD there much the same except the C542 has-
Nichion "MUSE" Capacitor's, does not say if the C521BEE has or not, Make a diffrence or not?
The output impedence is 150 ohms compared to 300 ohms on the BEE, a noticable diffrence?
Thats about all that I see on the sheets that are diffrent besides the Display.
Based on this would it be a better performing unit?
Thanks
Some of the price differential is due to having optical outputs on the 542, separate power supplies for analog and digital sections, and better internal components. Arguably, those are all potentially better. I'd see if I could audition each one in my home for a day or two.

While having lower output impedance is not inherently better, it can mean that you may be able to drive your amplifier directly by using attenuators instead of a preamp. I find that does improve the sound quality in one of my systems.

rw

[bappy]

No, these "specs" have virtually no meaning at all in terms of "better" performance. But I have two questions for you:

1. What are you going to be "feeding" the output of the CD player into?

2. Why have you narrowed your choices down to two units - both from NAD? Have you been taken in by their marketing hype - which leaves me so totally turned off that I wouldn't consider buying a NAD product ever, at any price? They violate a cardinal rule in business that says - " ... whatever you do, you do NOT "knock" or denigrate your competition".

There are a raft of competing models from which to choose from the likes of Denon, Marantz, Onkyo, Sherwood, and Yamaha. Nearly all sell for approx. the same price (or less) as the NADs and most of them weighing more than the two NADs (which both weigh in at a measly 9 lbs.). In an electro-mechanical device such as a CD player, a DVD player, a VCR, or a cassette deck, weight is a good indicator of how substantial is the "build quality".

Hope this helps you

Quote:

All I have to say is please do not go for Nad, please do go for Marantz SACD 8400 for buddegt pricing cd player. You will not be regret that you have done it.

Unquote:

Rgds,
bappy

[RobotCzar]

I am trying to decide between two CD players, the NAD C521BEE and the C542 which is about $200.00 more.
From comparing the spec and features of the 2, besides outputs and inputs, and one haveing 12 volt trigger and HDCD there much the same except the C542 has-
Nichion "MUSE" Capacitor's, does not say if the C521BEE has or not, Make a diffrence or not?
The output impedence is 150 ohms compared to 300 ohms on the BEE, a noticable diffrence?
Thats about all that I see on the sheets that are diffrent besides the Display.
Based on this would it be a better performing unit?
Thanks

I agree with woodman that you are looking at the wrong "specs". The audible specs of CD players are quite similar (and near the maximum possible with the redbook standard) which is why some people claim people can't hear differences among them.

Usually the frequency response of CD players is similar to that of an amp (i.e., nearly perfect). There can be differences in distortion and noise, particularly at high frequencies. You should look at distortion about 18 KHz and noise in general to distinguish the performance of the players. Of course, you are likely to find the differences are so small as to be inaudible. Therefore one is left with using "build quality" as one way to distinguish the players (sorry, no specs for this and you can't even assume that more expensive players are better built). The last distinguishing trait you do mention, features. I'd go by features, although I'd question whether things like HDCD support is a feature at all. Ouptuts and inputs ARE features of value.

As for weight, manufacturers have been known to add extra body metal to increase the weight of "special editition" components. There is, of course, no difference in performance or longevity unless you tend to bash the case.

[hermanv]

Although spec sheets may have some value in deciding what models to audition they are almost meaningless when it comes to sound quality.

Find a source that will let you listen at home or in a high quality audio environment (not in a big box retail emporium). Prefereably for a few days, put some effort in it, this stuff lasts for many years so you will probably have it a long time.

Manufacturers that brag about special parts do so because it costs them more. It is possible if not guaranteed that a manufacturer that applies the extra effort and cost will also use more effort in other areas of construction and design. Usually this is a good sign and these kind of efforts should move them higher on your possibilities list.

In the end the only thing that matters is how it sounds to you. If you hear no difference and the reliability seems equivalent buy the cheaper unit. If you don't know how to listen for those things that change form one manufacturer to the next, get someone with more experience to teach you. ( Danger: Learning how to listen carefully may cause irreversable damage to your wallet)

[RobotCzar]

Although spec sheets may have some value in deciding what models to audition they are almost meaningless when it comes to sound quality.
Perhaps hermanv means that specs for components other than speakers are meaningless because such components are all good enough these days that people cannot hear any differences among them (as both the specs and testing suggests).

He may also mean that the specs provided are inadequate for judging a component (beyond audible differences). In this case, he is partially right, a buyer should seek about as much data as possible in making a judgement, not just what the manufacturer (and the marketers) want to tell you.

But, alas, I fear he means that there is no relation between measurements and reality. The implication is that our senses detect that which cannot be measured, which doesn't make any sense to me. This is high end mythology without any support beyond the fact that the subjective perceptions of listeners do not relate to specs--which IS supported by data. Listeners hear lots of things as being different for a host of reasons other than specs (e.g., attitudes, beliefs, and expectations). Those things will never show up in specs.


Find a source that will let you listen at home or in a high quality audio environment (not in a big box retail emporium). Prefereably for a few days, put some effort in it, this stuff lasts for many years so you will probably have it a long time.You cannot "just listen" and get the truth for reasons mentioned above. Listening at home, is a very good idea. Listening in ANY store is suspect and should never be the basis of a purchase.


Manufacturers that brag about special parts do so because it costs them more. It is possible if not guaranteed that a manufacturer that applies the extra effort and cost will also use more effort in other areas of construction and design. Usually this is a good sign and these kind of efforts should move them higher on your possibilities list. Actually, too much bragging about things that do no matter is a sign of trying to appeal to the high end. In such cases, be prepared to pay more for nameplate status with little or no audible differences (except among speakers).


In the end the only thing that matters is how it sounds to you. If you hear no difference and the reliability seems equivalent buy the cheaper unit. If you don't know how to listen for those things that change form one manufacturer to the next, get someone with more experience to teach you. ( Danger: Learning how to listen carefully may cause irreversable damage to your wallet)If the only thing you care about is how it sounds "to you" without regard to other goals (e.g. accuracy to live performance), then by all means indulge your subjective side. Just don't pretend that your results apply to anybody but yourself.

[hermanv]

I hadn't looked at this thread for a long time, so I appologize for a very late reply.


Originally posted by ROBOT_CZAR
But, alas, I fear he means that there is no relation between measurements and reality. The implication is that our senses detect that which cannot be measured, which doesn't make any sense to me. This is high end mythology without any support beyond the fact that the subjective perceptions of listeners do not relate to specs--which IS supported by data. Listeners hear lots of things as being different for a host of reasons other than specs (e.g., attitudes, beliefs, and expectations). Those things will never show up in specs.

I am an EE and disagree that we hear things that can not be measured. I would rather say that there are a very large number of possible measurements that are not being performed. Additonally the measurement range of any but the very best test equipment believe it or not is not as good as human hearing. Musicians can easily tell you the frequency of a given note in a complex piece, test equipment is very poor at this if the note is short and mixed in with others

An example: I know of no automatic testing device that will verify that low level signals are not being differentially attenuated in the pressence of varying high level signals - huh? What I mean is that one thing that expensive electronics seems to do better to my ears is that quality we audiophiles call harmonic sustain. The ability to hear a single note die off slowly even thought the rest of the musicians have moved on. This is quite difficult to measure and as far as I know it isn't done. I could think of other measurements that aren't performed but I admit that I have little idea how any of these measurements in particular relate to those sound qualities audiophiles value.

As another example I own a Conrad Johnson power amplifier, the distortion specification is 1%. It sounds much better than an inexpensive receiverr whose distortion is only .01% The distortion number is interesting and might be used to gauge the quality of a design but has little value in gauging the quality of the sound.

This topic could use a very long discusion, maybe it's own thread. But it isn't safe to say every possible parameter of a design is already being measured so we can't say whether or not human hearing can hear things that measurments can not measure. But for now we can say for certain that some equipment qualites are simply not being measured

[E-Stat]

An example: I know of no automatic testing device that will verify that low level signals are not being differentially attenuated in the pressence of varying high level signals - huh? What I mean is that one thing that expensive electronics seems to do better to my ears is that quality we audiophiles call harmonic sustain. The ability to hear a single note die off slowly even thought the rest of the musicians have moved on. This is quite difficult to measure and as far as I know it isn't done.
What a wonderful description for that phenomena I was enjoying this evening. The opening band from the Harry Potter "Prisoner of Azkaban" soundtrack, for example, begins with a familiar xylophone tune. With most systems you hear the fundametal as the keys are struck but not the subtle metallic overtones as the harmony develops with the strings and woodwinds.

rw

[musicoverall]

This topic could use a very long discusion, maybe it's own thread. But it isn't safe to say every possible parameter of a design is already being measured so we can't say whether or not human hearing can hear things that measurments can not measure. But for now we can say for certain that some equipment qualites are simply not being measured

Agreed - I find it very hard to believe that we humans know everything about this subject. I think it's obvious (to my ears) that we aren't measuring everything there is to measure; hence we audiophiles hear things in a component that aren't measured or, as you discovered, a piece with less stellar measurements actually performs better than a piece measuring the opposite.

[musicoverall]

What a wonderful description for that phenomena I was enjoying this evening. The opening band from the Harry Potter "Prisoner of Azkaban" soundtrack, for example, begins with a familiar xylophone tune. With most systems you hear the fundametal as the keys are struck but not the subtle metallic overtones as the harmony develops with the strings and woodwinds.

rw

Nice example - wish I could think of a specific one at the moment but I hear this phenomena with regularity on my main system and I do not with my second system. There is certainly a scientific explanation for this but we don't seem to know what it might be at present. But it's one reason why it's bad advice to purchase a component based on specs alone.

[hermanv]

Most electronic measuring equipment applies a steady state signal to the device under test and then analyzes an also steady state output.

For example: a distortion analyzer might apply a 1V rms 1KHz. sine wave to the input of an amplifier (possibly for minutes at a time). On the output the instrument then filters out the 1KHz and displays by various means everything that's left. Then the whole spectrum of excess signal is usually summed into a single measurement called distortion. If you see distortion plots in Stereophile reviews for example, you will notice that the distortion spectrum and waveform itself varies all over the place yet the distortion is still usually quoted as a single number.

It is a useful tool, but very little about that process mimics music or how we hear things.

Most other equipment performance measurements are also long duration steady state signals.

Imagine auditioning audiophile equipment by listening to a single note several minutes long made by a flute and deciding which piece of electronics was best with this technique. (I picked the flute because I think it is closer to a sine wave note, unlike virtually every other instrument)

Music of course is a series of stops and starts both slow and fast, of all different notes or pitches, of several instruments each with a different harmonic structure with each musician starting and stopping his contribution a somewhat different times and all at various volumes. Measuring equipment simply does not do this. For me there is little surprize that the correlation between measurements and the sound quality of music is far from absolute.

Certainly much more complex measuring equipment could be invented. Although I do not work in an audio design capacity I do know that design shops in the end do listen to their product, some for extended periods . If measurement was the end all of sound quality they wouldn't bother

[RobotCzar]

Most electronic measuring equipment applies a steady state signal to the device under test and then analyzes an also steady state output.

For example: a distortion analyzer might apply a 1V rms 1KHz. sine wave to the input of an amplifier (possibly for minutes at a time). On the output the instrument then filters out the 1KHz and displays by various means everything that's left. Then the whole spectrum of excess signal is usually summed into a single measurement called distortion. If you see distortion plots in Stereophile reviews for example, you will notice that the distortion spectrum and waveform itself varies all over the place yet the distortion is still usually quoted as a single number.

It is a useful tool, but very little about that process mimics music or how we hear things.

Most other equipment performance measurements are also long duration steady state signals.

Imagine auditioning audiophile equipment by listening to a single note several minutes long made by a flute and deciding which piece of electronics was best with this technique. (I picked the flute because I think it is closer to a sine wave note, unlike virtually every other instrument)

Music of course is a series of stops and starts both slow and fast, of all different notes or pitches, of several instruments each with a different harmonic structure with each musician starting and stopping his contribution a somewhat different times and all at various volumes. Measuring equipment simply does not do this. For me there is little surprize that the correlation between measurements and the sound quality of music is far from absolute.

Certainly much more complex measuring equipment could be invented. Although I do not work in an audio design capacity I do know that design shops in the end do listen to their product, some for extended periods . If measurement was the end all of sound quality they wouldn't bother

For a professed EE, you are making some pretty strange claims.

First, a sine wave is not at all "steady state" but is in fact constantly changing its instantaneous value. This is a very common mistake made by high end pundits. I expect more from an EE. Summing the harmonic distortion components of a single frequency does result in a single number (THD), but one can look at the products if one wants to. A single number makes sense as you know that any single harmonic is less than that single number. I have suggested that people might want to check THD at high frequenciies to compare amp performance (not audible differences as there aren't any).

I don't know on what basis you claim that scientific measurments of reproduced sound (or electrical signals) do not "mimic" how we hear. Of course they do, that is why scientists make these measurements. The physical quantitiites measured like distortion, noise, dynamic range, flatness of frequency response exactly quantify reproduced sound. We must hear on the basis of these factors as they are all there is. The truth is that no human can detect differences better than instruments, in fact human hearing is subject to all kinds of subjecitve errors (audble illustions and effects due to expectations and context) that are useful for survival, but inaccurate.

You are completely wrong regarding simple versus complex audio signals. People are much better able to detect distortion, noise, and frequency flatness when pure sine tones are used (as opposed to music). So judging your system with a flute might be a good idea. As an EE it is astounding that you do not seem to accept that complex audio (and electrical) signals are made up of a set of pure sine waves. Complex signals are simply the superposition of simple sine waves. How is it you don't know this or don't believe it?

[skeptic]

"I expect more from an EE."

So did every professor of electrical engineering and mathematics I ever ran into. He should get a refund of his tuition money. You don't make it through any accredited engineering school in the United States and get an EE degree without understanding exactly how Fourier and LaPlace analysis of complex waveforms allows you to analyze, measure, and predict the performance of analog audio amplifiers using sine wave test tones to poduce the stadard Bodie plot of amplitude and phase versus frequency. It is deRigeur in course after course after course.

The problem with the commonly used measuring system for audio amplifiers is that they were invented at a time when far more primitive poorly performing equipment was the best that could be made and so these tests were more than adequate to characterize their differences and deviations from the textbook ideal model. While they can still show you salient differences and flaws of junky class A and class AB vacuum tube amplifiers audiophiles love with their irregular frequency response and high harmonic and intermodulation distortion, and input/output nonlinearities they are not sensitive enough to detect more subtle differences between equipment which otherwise measure textbook perfect because the tests do not mimic real world conditions. The problem is particularly obvious with power amplifiers measured on a test bench with an 8 ohm non inductive resistor as a load and then it gets connected in the real world to a complex reactive network consisting of several loudspeaker drivers and inductive and capacitave reactance components. Even worse, the loudspeaker drivers aren't even an entirely passive load. It is not that the measurements could not be refined and improved to differentiate these amplifiers to help us make more accurate evaluations, it's just that it hasn't been done yet. The most likely reason is that among sane rational people (not audiophiles) there are many amplifiers which fulfill all of their expectations perfectly. And in the rare and unusual case where someone needs a special amplifier to perform a special application in a lab such as to drive a special transducer, if they can't buy one, they design a custom unit to serve their immediate needs. The apparant mania among some audiophiles to endlessly try one amplifier after another after another and then purchase the oddball unit which is unique because of its gross defects is a sick obsession peculiar to them alone. It's the only explanation for the ability for some people to make and sell units costing $300 worth of parts including antique radio tubes for $30,000.

[mystic]

"I expect more from an EE."

So did every professor of electrical engineering and mathematics I ever ran into. He should get a refund of his tuition money. You don't make it through any accredited engineering school in the United States and get an EE degree without understanding exactly how Fourier and LaPlace analysis of complex waveforms allows you to analyze, measure, and predict the performance of analog audio amplifiers using sine wave test tones to poduce the stadard Bodie plot of amplitude and phase versus frequency. It is deRigeur in course after course after course.

The problem with the commonly used measuring system for audio amplifiers is that they were invented at a time when far more primitive poorly performing equipment was the best that could be made and so these tests were more than adequate to characterize their differences and deviations from the textbook ideal model. While they can still show you salient differences and flaws of junky class A and class AB vacuum tube amplifiers audiophiles love with their irregular frequency response and high harmonic and intermodulation distortion, and input/output nonlinearities they are not sensitive enough to detect more subtle differences between equipment which otherwise measure textbook perfect because the tests do not mimic real world conditions. The problem is particularly obvious with power amplifiers measured on a test bench with an 8 ohm non inductive resistor as a load and then it gets connected in the real world to a complex reactive network consisting of several loudspeaker drivers and inductive and capacitave reactance components. Even worse, the loudspeaker drivers aren't even an entirely passive load. It is not that the measurements could not be refined and improved to differentiate these amplifiers to help us make more accurate evaluations, it's just that it hasn't been done yet. The most likely reason is that among sane rational people (not audiophiles) there are many amplifiers which fulfill all of their expectations perfectly. And in the rare and unusual case where someone needs a special amplifier to perform a special application in a lab such as to drive a special transducer, if they can't buy one, they design a custom unit to serve their immediate needs. The apparant mania among some audiophiles to endlessly try one amplifier after another after another and then purchase the oddball unit which is unique because of its gross defects is a sick obsession peculiar to them alone. It's the only explanation for the ability for some people to make and sell units costing $300 worth of parts including antique radio tubes for $30,000.

Measurements might be a source of bias. If a listener believes in measurements, he might be inclined to think a solid-state amp which measures well will sound better than a tube amp which doesn't measure as well, despite a contrary preference of any audiophiles who have tried the two amps. He wants measurements to be the only indicator of quality, so he convinces himself that they are the only indicator, and thinks anyone who disagrees with him doesn't like good sound. However, although I am suggesting a technical background could color a listener's judgement, I have doubts about the strength of such bias. I have always been skeptical of the notion that a listener's perception is ruled by his attitudes, beliefs, and expectations.

[E-Stat]

I have always been skeptical of the notion that a listener's perception is ruled by his attitudes, beliefs, and expectations.
Especially when, for whatever characteristic(s) are assumed to "color" the perception are essentially the same. On more than one occasion, I have compared two completely new-to-me components at an audio reviewer friend's house that cost about the same, are of the same design (either both tube or both SS) and yet sound different to me. Line stages and power amps alike. That rules out ownership, brand, tube vs SS, and price. What's left?

It was all academic to me anyway considering their price!

rw

[jneutron]

That rules out ownership, brand, tube vs SS, and price. What's left?
rw
The ability of the power amplifier to provide adequate current slews to the load in a timely fashion, without being sensitive to input ground currents, low impedance power supply wiring stray magnetic fields, capacitor bank geometric magnetic fields, feedback loop coupling to all that high current hash within the chassis (after the T-network, of course).

None of these aspects are being considered...none..simply because the designers are rather clueless as to the actual nature and sensitivity of human stereophonic hearing, and how sensitive we really are to differential soundstage images..course, e/m theory helps a bit..but, first, the need for high level theoretical field understandings must be realized..till then, it's pissin in the wind..

It's a crying shame...somebody oughta do sumptin about it..you'd think some high end audio amp designer would care? (that, more than anything else I've seen, is the biggest shame....apathy..)

Cheers, John

[skeptic]

I don't see you doing anything about it John. And don't say you don't have the skill. Instead of wasting your spare time with those stupid wires, why do you take on a really big challenge and reinvent amplifier measurements or are you going to leave it to rank amateurs like you-know-who who tried to uninvent a hundred years of distortion testing and three hundred years of matematics. If not you who? If not now when? How about invading Nicaragua instead!

[jneutron]

I don't see you doing anything about it John. !Oh YAH!! well, same to you...
or:
Back at ya!!
or:
So!!!
or:...kinda runnin out of dumb things to say, so I'll stop..

Hey, how's it goin Skep? Been a while, I haven't actually seen much here to talk about..it's kinda dead..

But yes, I have been doin somethin about it....besides just complain..:-)

Finished most of the honeydoo's, plus removed and touched up the minivan slider door..luckily, rustoleum gloss primer matches plymouth minivan white exactly..coupla coats, and voila...can't see where the rust spot was..it was inside the door not out, go figure..

Workin on the aspect of human hearing which corresponds to localization and depth perception..the 3 D thing. It is somewhat incredible the IID's I'm getting when I consider the 3 D placement of an image...Far below that which is considered audible in the current research literature..so, I' m carefully going through the calcs, the assumptions, everything, to make sure I'm doin it correctly before I present it to some of the neurological researcher types..(regardless of what I show w/r to all the amp stuff I stated in the previous post, it is of prime importance to consider whether it is within the realm of audibility...I'm not entirely gone..:-))

Actually, had a really good discussion with a guy on tweaks concerning the use of dedicated lines and the loop pickup on the grounds....I hope he continues as I requested, and measures the source impedance of the loop. He measured 200 mVolts from ground to ground while a 1500 watt space heater was on one of the runs, so that signal was not IR induced, but rather, B dot..I want him to load ground to ground with a 1 ohm resistor and measure so that the IC ground current can be determined..amps do so little about ground currents coming in on the IC shield..


And don't say you don't have the skill. Instead of wasting your spare time with those stupid wires, why do you take on a really big challenge and reinvent amplifier measurements or are you going to leave it to rank amateurs like you-know-who who tried to uninvent a hundred years of distortion testing and three hundred years of matematics. If not you who? If not now when? How about invading Nicaragua instead!
Hey, no skill..but I did stay at a Holiday Inn last night...:-)

Actually, most of it is just re-arrangement of measurements, to consider the devices as three port things, where the input port has ties to the power port...and, real loads, not those dale NI thingies..

As for time...I'm in no hurry, it's just a hobby for me..

As for wires?...first, I'd like to understand the simple things..I've a ways to go before I understand how wires work..

Cheers, John

[E-Stat]

The ability of the power amplifier to provide adequate current slews to the load in a timely fashion...
Look again at Mystic's quote to which I replied. My question responds to the assertion that claimed sonic differences are solely due to attitudes, beliefs, and expectations. So which attitude, belief, or expectation of mine for these entirely new and completely unrelated amplifiers and line stages is responsible for my finding differences?

I completely agree that the standard metrics that are currently supplied with amplifiers are inadequate to fully describe their character. Your suggestions may be (part of) the key.


Actually, most of it is just re-arrangement of measurements, to consider the devices as three port things, where the input port has ties to the power port...and, real loads, not those dale NI thingies..
I never did get an answer from skeptic if distortion measurements are so definitive, then why is it that more than one manufacturer's current product has worse results than their designs of two or three decades prior? I think you'll find that those engineers would agree their current product is better, despite the apparent discrepancy.

rw

[jneutron]

Look again at Mystic's quote to which I replied. My question responds to the claim that claimed sonic differences are solely due to attitudes, beliefs, and expectations. So which attitude, belief, or expectation of mine for these entirely new and completely unrelated amplifiers and line stages is responsible for my finding differences?
rwYes, I did read both the quote and your response..you clearly pointed out that you have perceived differences in amplifiers for which you did not have attitudes, beliefs, or expectations..you stated complete detachment of ownership. And I tend to agree that given expectations, perception can be skewed..my statement was in response to your "what else" statement, and leads towards the changing of metrics.

What has been argued in the past is that... since the common metrics used now do not explain what is "heard", then, either the hearing is flawed, or the metrics are.

I find currently accepted metrics, based on currently accepted understanding of human localization and depth perception, to be somewhat inadequate to define spacial differential perceptions. Once human binaural perception capabilities are more readily understood, then re-defining the metrics upon which we define "goodness" of amplifiers will be a trivial matter. The amp guru's are not gonna have any problem figuring out how to test the product, and once a test can find what it needs to, figuring out what to do to the amp topology is gonna be a breeze..

Once I understood the mechanism behind the coupling between the power cord and the amplifier input (check out my discussion with Dave at AA tweaks), how to eliminate the power cord broadcast is trivial, as is the methodology behind modification of the amp front end to remove the IC ground current coupling effects..eventually this will become standard for all amps, but the big guys have to be shown that the problem exists..then they won't need to even see the techniques I employ to eliminate it...it will be obvious..you know, an "exercise for the reader".

Cheers, John

[jneutron]

I never did get an answer from skeptic if distortion measurements are so definitive, then why is it that more than one manufacturer's current product has worse results than their designs of two or three decades prior? I think you'll find that those engineers would agree their current product is better, despite the apparent discrepancy.rw
I believe the issue is one of "worse results"....how were those worse results determined? by measurements, by listening? Listening, for me, raises the ugly spectre of the GSIC flim flamm...how to do it without the results being tainted by that darn expectation bias stuff..

My gut says the measurements aren't looking at soundstage metrics, but simply FFT's of the product under low bandwidth loads..FFT's cannot determine adequacy of soundstage reproduction..tools do not exist to do that yet..they will, but not yet.

Distortion measurements are definitive for monophonic accuracy.

Cheers, John.

PS...hold still, will ya...you edited while I replied...:-)

[E-Stat]

...my statement was in response to your "what else" statement, and leads towards the changing of metrics.
Got it. You likewise dismiss ABEs as the sole source as well.


...how were those worse results determined?
I'm referring to simple THD. Higher distortion specs.

I'm sure skeptic will enlighten you as to how three hundred years of mathematics supports the notion that a single weighted number quantifies all the audible factors of how electronics reproduce a musical signal. ;)

rw

[jneutron]

Got it. You likewise dismiss ABEs as the sole source as well.rw
I would ask you to please not put words in my mouth, or make statements of my attitudes or beliefs..It would be easier for me to form an opinion on a specific topic if I knew what the topic was...

What is an "ABE"...and, why do I dismiss it as a "sole source"??? Curious minds want to know...:-) I'm curious ( I will admit, though, that ABE's aren't too bad, but I prefer Jacksons, Hamiltons, Grants, and Franklins...I recall Chase's are no longer printed..)

Also, why did you feel the need to attribute that to me?


I'm referring to simple THD. Higher distortion specs.rw
That is what I believed you were referring to.. And, as I stated, those numbers are more than adequate for monophonic reproduction..give or take...unless, of course, you include TIM, time based instability as a result of the output section being unable to follow the setpoint, invoking saturation in an intermediate gain stage. Or, four quadrant damping factor, driving a reactive load....and temporal accuracy in all four quadrants..that is only now in it's infancy, the papers I've seen, while woefully inadequate, are at least a start.


I'm sure skeptic will enlighten you as to how three hundred years of mathematics supports the notion that a single weighted number quantifies all the audible factors of how electronics reproduce a musical signal. ;)rw
He has presented a good argument along that line, but I'm sure his actual argument is about a set of numbers, like levels of the harmonics...The addition of a whole slew of additional frequency components to determine non-linearities is not consistent with a rather huge base of applied mathematics, which is easily capable of a deterministic understanding of non linearities with two or so different frequencies... This is simply a case of loading the belt with more and more chocolates and then speeding up the belt..in the hopes that something meaningful will pop out..there was absolutely no mathematical rigor behind J's technique, and nothing of any additional value as perceived by the big guns in signal analysis was to be found..

If the technique had any merit, it would be in use now..HP, AP...name a biggie..

As for skeptic's belief that that is all that is required, I do not subscribe to that notion. I believe the metrics require changing..

It is not my intention to ignore the rather large world of test equipment and amplifier analysis techniques..that would be silly..

It is my intention to change it..with rigorous analysis, test, and reproduceable results, not by calling people naysayers, and claiming papers were rejected because they hated me..

Cheers, John

PS...you seem to be intent on either picking a fight, or just arguing with me..this, I do not understand..I guess you missed me??? :-)

[E-Stat]

What is an "ABE"
Sorry - an acronym for that which we've been discussing: Attitudes Beliefs Expectations.


...unless, of course, you include TIM, time based instability as a result of the output section being unable to follow the setpoint...
And few do.


If the technique had any merit, it would be in use now..HP, AP...name a biggie..
Indeed. You're preachin' to the choir.


It is my intention to change it..with rigorous analysis, test, and reproduceable results
Sure. No need to throw the baby out with the bathwater. Until limited metrics are refined, however, they will continue to be next to useless.


you seem to be intent on either picking a fight, or just arguing with me..this, I do not understand..I guess you missed me??? :-)
Not at all. We're in complete agreement. :)

1. Attitudes, beliefs, and expectations (ABEs) do NOT explain perceived differences when those factors are absent.
2. Traditional THD specifications devoid of the factors you mention do not fully characterize the ability of an electronic component to deliver a stereo signal of musical content.
3. More work needs to be done. Audio engineers and test equipment engineers alike understand that it isn't as simple as skep opines.

rw

[jneutron]

Sorry - an acronym for that which we've been discussing: Attitudes Beliefs Expectations. rw Oh, ok...darn, I was kinda hopin for some 5 dollar bills to come my way:-)/



Until limited metrics are refined, however, they will continue to be next to useless. rwOn the contrary, they are very useful for arguing..:-)

Actually, the current metrics are great...they just don't cover soundstage localization..



We're in complete agreement. :)rwWhat, that you missed me??? I'm blushing...(sorry, couldn't resist that)


Audio (#) engineers and test equipment engineers alike understand that it isn't as simple as skep opines.rwActually, I think what skep opines is pretty much accurate for the standards of the engineering community at large..I'd disagree with him if there were some real papers out there which contradicted what he has said, but there isn't. There is a lot of floob, but nothing rigorous..yet.

Cheers, John

[E-Stat]

Actually, the current metrics are great...they just don't cover soundstage localization..
And shrill high frequency reproduction. The THD of my former '74 Crown amp was about one-tenth that of an '81 Threshold Stasis amp I now use, but it sure was hard as nails on top. Crown is one of those companies I referrred to with newer products having higher distortion figures, yet better sound.


Actually, I think what skep opines is pretty much accurate for the standards of the engineering community at large.
There's nothing wrong with good enough. For most folks, a Ford Taurus is good enough. For that matter, the same could be said for a Bose Wave Radio! :)

rw

[jneutron]

And shrill high frequency reproduction. The THD of my former '74 Crown amp was about one-tenth that of an '81 Threshold Stasis amp I now use, but it sure was hard as nails on top. Crown is one of those companies I referrred to with newer products having higher distortion figures, yet better sound.rw
As you state, which we agree on, those results do not correlate directly to the absolute levels of THD.

One can take different stands on this...

1. The introduction of various levels of distortion, odd, even, 6th, 7th, whatever, introduces some mysterious sonic quality that either truncates, lowers, diverts, (insert some floob word) the sonic "synergy", invoking quantum whatever, placates the ear, any amount of nonsense. I think most are aware of my stance on making crap up that sounds technical enough to fool some.

2. It is not there, and you are fooling yourself...I'm sure most are aware of my stance on this...

3. It is THD that you are hearing, but the amps are reacting differently to the load you have presented, a load which the amps were not origionally tested to. When one considers the fact that typical resistors like the dale NI products, do not heavily load high slew rate voltages, I could see this possibility..

4. It is how the amp plays with complex signals, into a complex load, with a complex power delivery system, and a hugely complex grounding system at the front end, and a very complex, totally uncharacterized end receiver (us), which is sensitive to things that are not being measured...I am sure that most understand that this is my take..


There's nothing wrong with good enough. For most folks, a Ford Taurus is good enough. For that matter, the same could be said for a Bose Wave Radio! :)
rw
The term "good enough" must be banished from the planet.

The term should be "meeting criteria".

Mac'd's meets criteria.
Volkswagen bugs meet criteria.
Radio Shack meets criteria.
Minivans meet criteria..
My mobile rig meets criteria..
Even Bose meets criteria..

Once the engineering community understands what I see, they will re-define the criteria..and then, they will meet it..trivially, I might add..it is a no brainer to correct once it is seen. The reason I see it is because my day job is e/m field theory..it isn't the actual circuitry of the amps (countless professionals out there are far better at that than I), it's how it's put together..

Cheers, John

[E-Stat]

The term should be "meeting criteria".

Mac'd's meets criteria...

Once the engineering community understands what I see, they will re-define the criteria..
Well said.

rw

[RobotCzar]

Yes, I did read both the quote and your response..you clearly pointed out that you have perceived differences in amplifiers for which you did not have attitudes, beliefs, or expectations..you stated complete detachment of ownership.

Any claim of no attitudes, beliefs, or expectations is ridiculous. We are not always conscious of these things. It is rather like a person claiming that they are not biased. Is the claim sufficient to rule out bias. I think not.

In this case the claim is known to be wrong as the listener in question has repeated stated the "belief" that there are audible differences in amplifiers and they are related to "qualitfy" and cost. Um, I think that is an prexisting attitude, belief, or expectation. The fact that he hasn't decided if a new amp sounds good yet is irrelevant.

I must also say that in my opinion you are correct about spatial imaging being THE key factor of need in home audio. But, I totally disagree that this is in some way related to amp design. It is releated to recording practices, the fact that we (usually) have only two playback channels, and the dispersion properties of the speaker and room. Even if your hypotheses about electronic amplification of the signal have any validity, that factor is very small in magnitude compared to the factors I have mentioned. Our spatial perception of sound is primarily based on differences between channels (actually differences in the arrival of sound at our ears which is affected more by room and speaker than the electronic signal differences of the amp), not the quality of the signals on the channels (which are of sufficient quality to be non-factors in regard to spatial imaging).

Multichannel has the potential to greatly improve the poor 3D performance of home audio, but that potential is being wasted so we can have "theater sound".

[E-Stat]

In this case the claim is known to be wrong as the listener in question has repeated stated the "belief" that there are audible differences in amplifiers... Um, I think that is an prexisting attitude, belief, or expectation.
And transcends beliefs and attitudes as that notion is supported by empirical evidence. Both DBT and ABX testing has established that amplifiers sound different.

As to my specific comment, I had no preconceived notions concerning the components compared.

rw

[jneutron]

Hi RC..been a while, hows it going?


Any claim of no attitudes, beliefs, or expectations is ridiculous. We are not always conscious of these things. It is rather like a person claiming that they are not biased. Is the claim sufficient to rule out bias. I think not. """.
He stated a lack of bias towards a coupla amps that all exceeded his monetary desires..so in that case, it didn't seem to be a cost issue..you do raise valid points, of course. But, is it intellectually correct to simply disavow all perceptions as being inaccurate by painting broad strokes?..no, but awareness of the issue is a prime consideration..


In this case the claim is known to be wrong as the listener in question has repeated stated the "belief" that there are audible differences in amplifiers (http://forums.audioreview.com/newreply.php#) and they are related to "qualitfy" and cost. Um, I think that is an prexisting attitude, belief, or expectation. The fact that he hasn't decided if a new amp sounds good yet is irrelevant. .
No. The claim cannot be considered wrong given those reasons. The claim is certainly un-supported as a result of those reasons, but not necessarily correct or incorrect. It is good scientific method to raise the concerns you speak of. But the expectation or belief does not mean the listener is incorrect...

I must also say that in my opinion you are correct about spatial imaging being THE key factor of need in home audio (http://forums.audioreview.com/newreply.php#). But, I totally disagree that this is in some way related to amp design.That's ok. you are entitled to your opinion...eventually, what I know and understand may change your mind...here, for example, is one of the simpler tests I'm workin on..

Can you tell me exactly how an amp will respond under this condition:
1. Connect a load.
2. Plug the amp in.
3. Plug a 6 foot IC into the input.
4. Short the far end of the IC.
5. Turn the amp on...there should be no output.
6. Drive 1 ampere of sine current between the RCA shield at the input jack, to the Ground of the wall outlet. Run the sine from 20 hz to 500 Khz.
7. Monitor the output for anything..Set a spec...1 volt, 10 volts, whatever..

This test determines the amp sensitivity to ground loop currents. How may amplifier designers do it??? How may users have had ground loop problems??This test is a start, there are several more that need to be done..The ability to pass this test means the amp will not have ground loop problems, will be far more insensitive to line cord differences, will probably not require dedicated outlets, will be less susceptible to bridge rectifier speed concerns, power supply capacitor types..to name a few front end benefits. ...I could detail the improvements with respect to the audio signal, but h**l, even eliminating ground loop sensitivity is more than worth the cost of the test....

And, all this just by invoking some musings of a dead guy by the name of Faraday..his law of induction..;-)


Honestly, you do not think of amp design as I do..I assume the internal circuitry is good, and speak only of the external geometry..


It is releated to recording practices, the fact that we (usually) have only two playback channels, and the dispersion properties of the speaker and room. Even if your hypotheses about electronic amplification of the signal have any validity, that factor is very small in magnitude compared to the factors I have mentioned. Our spatial perception of sound is primarily based on differences between channels (actually differences in the arrival of sound at our ears which is affected more by room and speaker than the electronic signal differences of the amp), not the quality of the signals on the channels (which are of sufficient quality to be non-factors in regard to spatial imaging).Actually, I'm not talking about the amplification, just the errors that creep into the system.

Spacial perception is time diff and level diff..this develops the 3-d soundstage..

Specifications on time diffs is non existant..Specs on amp diffs exist only w/r to JND of single channel stuff...not localization...that will be a tad more stringent than is currently accepted.

You state that the signal quality is sufficient for spatial imaging...upon what are you basing that?..have you been holding out on me?? :-) To assert that, you must be able to define human localization differential sensitivity to both ITD and IID stimulus, and then the signal specification necessary to assure deviation is below some arbitrary window, say a 1 sigma level for localization in space to the 1 foot level....I see absolutely NOTHING that even comes close to hinting or even guessing along those lines...you know of some studies along those lines?

As always, RC....a pleasure..

Cheers, John

OH, where's my manners....gotta have a picture of the day....

[RobotCzar]

Sorry to take so long to respond, but I want to note that I read your comments.

You say "Spacial perception is time diff and level diff..this develops the 3-d soundstage". I agree. We localize sounds by small differences in level and arrival time between our two ears. My point is, without quantitative support, that differences in those factors (time and level) induced into the two channels by an amplifier are much much lower than differences induced by the room, and the position of the speakers in relation to one's ears, and other factors. My assumption is based on the low differences between the electrical signals simultaneously driven in home amps.

Can you clarify your position by telling me if your concern about localization affects from amps is confined to differences among the channels (not oval amp performance, in say, ground loops which seem to have no connection to channel differences). You can have any option you want, but is it your opinion that localization is due exclusively to level and timing differences BETWEEN the channels? If not, then my opinion is that you are totally on the wrong track regarding localization of sounds from home audio systems.

If you, like me, are concerned about the 3D abilities of home audio, then you would be concerned more with the factors that obviously affect between channel differences such as recording techniques, speaker placement (and prerformance), and room configuration. I assume that differences in amp channels, whether or not those channels have good performance, is low---one might say very low, and of little concern to home audio fans concerned with 3D.

On the other point, the writer claimed no bias, I think he has clearly displayed bias (as I pointed out) and therefore is wrong. If you perfer that I say that the evidence supports the idea he is wrong, okay. If you imply that that evidence does not support the idea that the writer was wrong in claiming no bias, I disagree.

[jneutron]

Sorry to take so long to respond, but I want to note that I read your comments.

You say "Spacial perception is time diff and level diff..this develops the 3-d soundstage". I agree. We localize sounds by small differences in level and arrival time between our two ears. My point is, without quantitative support, that differences in those factors (time and level) induced into the two channels by an amplifier are much much lower than differences induced by the room, and the position of the speakers in relation to one's ears, and other factors. My assumption is based on the low differences between the electrical signals simultaneously driven in home amps.

Can you clarify your position by telling me if your concern about localization affects from amps is confined to differences among the channels (not oval amp performance, in say, ground loops which seem to have no connection to channel differences). You can have any option you want, but is it your opinion that localization is due exclusively to level and timing differences BETWEEN the channels? If not, then my opinion is that you are totally on the wrong track regarding localization of sounds from home audio systems.

If you, like me, are concerned about the 3D abilities of home audio, then you would be concerned more with the factors that obviously affect between channel differences such as recording techniques, speaker placement (and prerformance), and room configuration. I assume that differences in amp channels, whether or not those channels have good performance, is low---one might say very low, and of little concern to home audio fans concerned with 3D.

On the other point, the writer claimed no bias, I think he has clearly displayed bias (as I pointed out) and therefore is wrong. If you perfer that I say that the evidence supports the idea he is wrong, okay. If you imply that that evidence does not support the idea that the writer was wrong in claiming no bias, I disagree.As always, a pleasure to read from you...

The model I am working on uses the level and timing differences exclusively, for localization. IOW, that is all I am considering for now.

It does not include front/back discerning, nor up/down.. It is strictly the propagation of sound through the air, absolutely no inclusion of how the localization works from the ears to the brain..

Recording techniques: mike placement is better considered from experience, my work does not directly apply to that..maybe it'll somehow, eventually filter there, but I do not consider it.

Mixdown to the final 2 channel, what I work on affects that big time. Where the recording engineer wishes to place the image...he is hindered by the tools available to him.. A pan only board does not place images in the way we perceive them.

I am having enough of a task workin the equations for point sources in an anechoic environment..the mapping algorithms from two speakers to a virtual image is getting interesting. Lord knows, room and speakers is very important, but intractable for the moment. I'm just doin the simple stuff first.

Cheers, John