[Febs]

Quote:

Originally Posted by memepool /img/forum/go_quote.gif Although both would no doubt claim to adhere to the same scientific principles the difference is that one actually listens to his equipment and the other quite obviously doesn't look further than the end of his slide rule.

If you read some of his reviews, it is "quite obvious" that he does "actually listen to his equipment." For example, he writes, "Audio is about listening and every piece of audio equipment stands or falls on its performance in the listening room. Listening is an all-important part of equipment evaluation ...." He qualifies that latter sentence by explaining that listening needs to be structured and meaningful in order to provide a valid basis for evaluation, but he clearly values listening in the evaluation and review process. In fact, he goes on to observe that, "even under properly controlled listening conditions numerous audio components will sound different and therefore require subjective evaluation."

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Science is about empirical observation not arguing from a priori first principles. If enough people claim amps sound different then the question is why do they sound different and what other measurements should be made to try and explain this, rather than denying there is any difference in the first place. That's called dogma.

Again, Aczel does not claim that all amps sound the same. He claims that all amps that measure the same sound the same, and that differences in sound can be empirically observed.

For example, on page 14 of the article I linked to, he writes

Quote:

Originally Posted by The Audio Critic If a piece of electronics has flat frequency response, vanishingly small static and dynamic nonlinearities, a high enough input impedance and low enough output impedance, a noise level below audibility, and high enough channel separation, then it is not going to have a sound. ABX testing confirms this. That is not to say all amplifiers sound the same. Clearly an amplifier can have insufficient voltage- and current-drive capabilities for a given loudspeaker and that is going to be audible. Our test regime is designed to identify wimpy amplifiers. Amplifiers are also going to sound different if they do not satisfy the above conditions.

 

[hciman77]

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Originally Posted by Epicurean /img/forum/go_quote.gif Well I had a friend of mine change the board while I was listening, isn't that the way it is supposed to be? Everything else stayed the same and volume control at the same level.

However, that does not mean the output levels from the DAC were identical, the output from my external DAC is a full 0.5V higher than the output from the bulit-in DACs on my old NAD or my current Marantz. It doesnt mean there isnt a difference but it is another variable. Can you check the output voltage from the DAC with the two different boards in place, even a small level difference may be percepually different.

 

[hciman77]

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Originally Posted by daltonlanny /img/forum/go_quote.gif I have to say, reluctantly, that I do have to believe this to a certain extent after an experiment I did tonight. I level matched my headphone jack on Onkyo DX-7555 Cd player, my Creek OBH-11 SE [a $250.00 amp], Heed CanAmp [a $400.00 amp], and a Headroom Max [a $1,400.00 amp], using Sennheiser HD600 and HD650 headphones, and a Radio Shack Sound Level Meter. Results: They ALL sounded the SAME to me!!! No joke. The headphone jack on my Cd player sounded the same as the Headroom Max...what a disappointment! I also level matched my daughters portable Sony discman, [8 years old], and my Music Hall CD25.2 Cd player. I listened to them through both the Sennheisers and the AKG's using the Headroom Max. Results: They sounded the same! And this was even by visually knowing which one was playing at any given time! How could this be???

With the money gained from selling superfluous hifi kit you can buy a lot of CDs !. I have had the exact same experience, after years of self denial I had to admit that to me many pieces of hifi really do sound the same, now I have the cheapest source I have ever owned from new and more musical happiness than ever before...

My favourite ABx test is the 12,000 Euro Oracle Cd player vs the 200 Euro Pioneer DVD player, where nobody could tell the difference, call me old fashioned but when there is a difference of 60x or +11,800 Euros I dont want a subtle difference

 

[Kevin Sinnott]

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Originally Posted by balou /img/forum/go_quote.gif I feel offended by mr. aczels statement, and I think everybody else who likes music will feel so too. he's defaming most people on this forum who dare to say they like one amp over another, he's defaming every person in the world who likes tube sound. to make matters worse, he mixes completely unfounded critics with real ones. I do agree with him that various 'miracle cures' are a mere ripoff - but from the other things he said, you can't really rely on him. is it just another smear campaign, or is it a valid critic - you never know with people like mr. aczel

I want to encourage you not to feel offended by Mr. Aczel. I was a long-time reader of the Audio Critic and I think over the years grew to appreciate what Aczel was about and doing. I agree he sometimes went over the top in his headlines, but he was fighting the good fight against charlatans.

I happen to listen to a single-ended tube unit. I think Mr. Aczel would say I am purposefully seeking out a high-distortion unit. I'm not in disagreement with that, but I happen to enjoy it. Where I think Mr. Aczel errs, along with others in a so-called objectivist camp is we may not know enough about how people listen or what they seek.

Aczel has a purpose and he has swam against the tide on many occassions. He isn't always right, but I believe he is sincere.

 

[Epicurean]

Quote:

Originally Posted by hciman77 /img/forum/go_quote.gif However, that does not mean the output levels from the DAC were identical, the output from my external DAC is a full 0.5V higher than the output from the bulit-in DACs on my old NAD or my current Marantz. It doesnt mean there isnt a difference but it is another variable. Can you check the output voltage from the DAC with the two different boards in place, even a small level difference may be percepually different.

While I haven't measured the loudness difference, I perceive them as being about equally loud when the volume control is at the same level. In any case the soundstage does not change when turning the volume up and down as it does when changing the boards. Turning a string of 1s and 0s to an analog signal isn't as simple as it sounds and manufacturers use different techniques to do this which might result in audible differences. The difference is even greater when comparing to a NOS dac, which shows clear and errors in the upper frequencies but people like them nonetheless.

The dac chips I have in my Zhaolu do not measure exactly the same, and I don't think any two different dac chips do, so if the requirements for 2 digital players to sound the same is to measure the same then there you have it!

 

[Mr_Sukebe]

Whilst I may consider putting an component on a hit list to be listened to, I'd NEVER EVER buy a product because of how well it tested. There are just too many variables, including:
- Quality of the listeners. e.g. my mother really does claim that she can't tell the difference between any system, regardless of cost. Wouldn't be good if her and her friends made up half of a listening group
- Bias. Some people are inately biased, because they either own the product or sell it
- Personal preference. One thing I've learned is that different people like different styles of presentation. So for example I certainly wouldn't buy a system recommended by say a Naim owner, not that Naim kit is bad, just that it's not what I'm looking for.
So I don't care whether a test is double, treble or multi-bit blind, I'll still rely on my own ears to make the decision on whether a product is worth the cash.

With regard to differences between sources. I genuinely don't believe that someone twisted my arm, or that I get a kick out of bragging rights about what I have as a source. Which to me infers that I bought it because I thought it was worth the extra over a £50 DVD player.
Moreover, I still believe that there's more to come, as I've heard a £10k Esoteric X-01, which really was the best source I've yet heard.

Hope that helps.

 

[zheka]

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Originally Posted by Redo /img/forum/go_quote.gif Richard Clark even admits that the testing and in home results would vary quite a bit.

would you point me to this admission? i must've missed it somehow

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Originally Posted by Redo /img/forum/go_quote.gif Then one would have to play the amp below clipping range. However, specifically in the case of tubes, a small bit of clipping can be very pleasing to the listener. There's a big reason why electric guitar sings to so many people, and it has to do with tubes being pushed into overdrive.

I agree that, when overdriven, tube amps sound different from transistor ones. this may have utility for sound effect devices but it is hardly a virtue for playback components

my personal preference is for faithful sound reproduction , not for heavy distortion, pleasant or otherwise

Quote:

Originally Posted by Redo /img/forum/go_quote.gif Solid State needs to have relatively insane power ratings compared to tubes. Start overdriving transistors and it's no longer fun.

in my experience most power amps these days -both tube and ss - never have to be pushed into clipping range. That is if one excludes low power SET and Tripath based amplifiers

 

[memepool]

Quote:

Originally Posted by Febs /img/forum/go_quote.gif Again, Aczel does not claim that all amps sound the same. He claims that all amps that measure the same sound the same, and that differences in sound can be empirically observed.

That is what he seems to be saying here

Quote:

Every low-distortion electronic signal path sounds like every other. The equipment reviewers who hear differences in soundstaging, front-to-back depth, image height, separation of instruments, etc., etc., between this and that preamplifier, CD player, or power amplifier are totally delusional.

 

[hciman77]

Quote:

Originally Posted by memepool /img/forum/go_quote.gif That is what he seems to be saying here Quote: Every low-distortion electronic signal path sounds like every other. The equipment reviewers who hear differences in soundstaging, front-to-back depth, image height, separation of instruments, etc., etc., between this and that preamplifier, CD player, or power amplifier are totally delusional.

I think this is the key to this argument. For Aczel if two signal paths do not add any (or significant) variations (distortion) from the original signal then they should sound the same.

How I read this is that Aczel discounts

Quote:

soundstaging, front-to-back depth, image height, separation of instruments

as being wholly dependent on the known measurable parameters and if these known measurable parameters are the same then there should be no difference. The problem with

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soundstaging, front-to-back depth, image height, separation of instruments

is that these are by and large highly subjective measures that you just cannot mathemetically quantify, if you cannot quantify them then how do you compare them other than by er, subjective measures and how do you know when they really differ, some days my kits sounds nicer than others, I cant explain this using physics, I suspect it involves my mood in some way.

Though I think slight timing variations between channels do give rise to the illusion of greater separation and these are at least measurable - some first gen CD players had some issues with shared circuitry that gave rise to timing issues between channels - as it happens you can sometimes pick these up in blind tests

I dont wholly agree that everything always sounds the same, but if things sound different then I think there is a rational explanation that is bounded by the laws of the physical universe and doesnt require any extra Q factors, but if some bod discovers some previously unknown factors it would be interesting, but I want them to at least own a decent white coat and hopefully a domed forehead...

 

[Febs]

Quote:

Originally Posted by memepool /img/forum/go_quote.gif That is what he seems to be saying here

If you read some of Aczel's other writings, he elaborates on the statement that you quote. I quoted one such explanation in my prior post. You can find another in the two introductory paragraphs on parge 25 (page PDF 21) of this publication. At the risk of oversimplifying, I think that Aczel's philosophy is:

1. When listening under controlled conditions (i.e., with level matching to within <.2 dB), all power-amps, CD players and pre-amps with sufficiently good measurements sound the same, and this has been repeatedly demonstrated in ABX tests.

2. Some components do sound different, and for that reason, listening tests are a critical part of any review.

3. Where components sound different, the differences can be attributed to identifiable and measurable characteristics.

As Kevin Sinnott noted above, Aczel's writing style was somewhat inflammatory, which I think is unfortunate. You can certainly criticize him for that and obviously, you are free to disagree with his philosophy or his conclusions, but I think that it is unfair to label him as dogmatic or unscientific based on some isolated statements taken out of context.

 

[JadeEast]

Well looking at the original test its obvious that
the portable cd player sounded as good as the
more expensive source because of extensive
burn in.

 

[ex0du5]

I like this fellow.

He thinks like I do

.

 

[Redo]

Quote:

Originally Posted by zheka /img/forum/go_quote.gif would you point me to this admission? i must've missed it somehow

Does this mean all amps sound the same in a normal install?

No. Richard Clark is very careful to say that amps usually do not sound the same in the real world. The gain setting of an amplifier can make huge differences in how an amplifier sounds, as can details like how crossovers or other filters are set. When played very loud (into clipping), the amplifier with more power will generally sound better than a lower powered amp.



In other words, synergy between equipment plays a big role.

 

[zheka]

i do not think that the quote has anything to do w/ synergy
what it means is that for valid amp comparisons you must match output levels, disable amp signal processors if any, make sure that polarity is matched and that there is no signal phase inversion, etc. (see Amplifier Comparison Test Conditions http://www.tom-morrow-land.com/tests...ll/rcrules.htm )

as RC puts it, "It is our job to carefully match the amps so that we are comparing "apples to apples" instead of "oranges to frogs." "

 

[Hi-Finthen]

I'll suggest a good many of these E.E.s and people who hear no difference are tone deaf and should stick to listening to AM car radios or a diskman and applebuds for sound...lol

But no, they MUST tell their science to people who experience a difference... Internet ******* and a dime a dozen! lol