What makes a high end audio amp "better" then a low end unit?

[Alex Nikitin]

Back in 1978...

Well, a perfect example of a wasted effort. The whole idea that the test like this is valid is not scientific. Unless we validate the test with a statistically correct positive result (i.e. the difference would be established which can be reliably perceived by the audience in the particular conditions of this test), the negative result means nothing and can not be used as an argument.

Cheers

Alex

[nfmax]

Back in 1978...

Well, a perfect example of a wasted effort. The whole idea that the test like this is valid is not scientific. Unless we validate the test with a statistically correct positive result (i.e. the difference would be established which can be reliably perceived by the audience in the particular conditions of this test), the negative result means nothing and can not be used as an argument.

Cheers

Alex

Are you really saying that unless we can prove the positive result we cannot prove the negative result? Or do you mean that unless we can introduce some deliberate modification into one of the amplifiers under test that is detectable in a double-blind test, we have not established the validity of the double-blind test as a test?

In that case, it's easy: just increase the signal levels to the point where one of the amplifiers starts clipping, or going into current overload. Then you will hear differences a-plenty!

Disclaimer: A long time ago, I used to work at QUAD, as the junior lab engineer. My one claim to fame is developing the revised current limit circuit that turned the 405 power amplifier into the 405-2.

[Alex Nikitin]

In that case, it's easy: just increase the signal levels to the point where one of the amplifiers starts clipping, or going into current overload. Then you will hear differences a-plenty!

That is the very reason why it is never done - it would show how insensitive the test of this kind is. If we are trying to spot the differences near the limit of our perception but the test conditions make it possible to spot only really gross differences, the test is not good for the intended use. Same if you try to measure a difference between two 9V batteries with a needle meter at 1000V range. That is why I only can regard this kind of DBT in audio as pseudo scientific. And so many people actually believe that crap and accept it as a "scientific proof"  !

Cheers

Alex

[Zero999]

Back in 1978...

Well, a perfect example of a wasted effort. The whole idea that the test like this is valid is not scientific. Unless we validate the test with a statistically correct positive result (i.e. the difference would be established which can be reliably perceived by the audience in the particular conditions of this test), the negative result means nothing and can not be used as an argument.

Cheers

Alex

Are you really saying that unless we can prove the positive result we cannot prove the negative result? Or do you mean that unless we can introduce some deliberate modification into one of the amplifiers under test that is detectable in a double-blind test, we have not established the validity of the double-blind test as a test?

In that case, it's easy: just increase the signal levels to the point where one of the amplifiers starts clipping, or going into current overload. Then you will hear differences a-plenty!

Disclaimer: A long time ago, I used to work at QUAD, as the junior lab engineer. My one claim to fame is developing the revised current limit circuit that turned the 405 power amplifier into the 405-2.

The test seems to be perfectly valid.  I don't see how anyone from a scientific background can say otherwise. Arguments against this kind of test seem to be very similar to advocates of spiritual healing vs tried and tested medical treatments.

Providing the amplifiers in the test were operated within their ratings, they were indistinguishable.  No doubt one would get a similar result with modern audio amplifiers. Of course how the amplifier responds to overloads is also a valid reason for why some prefer value/tube amplifiers over solid state amplifiers, but that wasn't the purpose of the test, which was to determine if solid state amplifiers could be made to sound like valve amplifiers.

Perhaps another test could be done, where distortion is deliberately introduced up till the point, where it becomes noticeable beyond chance?

Another interesting test would be a digital processing system, designed to emulate the distortion of a valve amplifier, vs the real valve amplifier.

[Alex Nikitin]

The test seems to be perfectly valid.  I don't see how anyone from a scientific background can say otherwise. Arguments against this kind of test seem to be very similar to advocates of spiritual healing vs tried and tested medical treatments

Oh, a strictly necessary requirement to establish a base line of a test sensitivity (otherwise how we know what we testing) now suddenly becomes something mystical?! 

Cheers

Alex

[Zero999]

The test seems to be perfectly valid.  I don't see how anyone from a scientific background can say otherwise. Arguments against this kind of test seem to be very similar to advocates of spiritual healing vs tried and tested medical treatments

Oh, a strictly necessary requirement to establish a base line of a test sensitivity (otherwise how we know what we testing) now suddenly becomes something mystical?! 

Cheers

Alex

Why is that necessary?

The test proves that human ear is insensitive to any differences between the amplifiers used in the test. Therefore if one is deciding which amplifier they want to use, they should focus on other things than perceived sound quality, such as: cost, reliability, availability of spare parts, response to overload etc.

I agree, it would be interesting to know the point at which distortion becomes noticeable and whether or not it's pleasing to the listener, but that was beyond the scope of the test.

[Alex Nikitin]

The test seems to be perfectly valid.  I don't see how anyone from a scientific background can say otherwise. Arguments against this kind of test seem to be very similar to advocates of spiritual healing vs tried and tested medical treatments

Oh, a strictly necessary requirement to establish a base line of a test sensitivity (otherwise how we know what we testing) now suddenly becomes something mystical?! 

Cheers

Alex

Why is that necessary?

The test proves that human ear is insensitive to any differences between the amplifiers used in the test.

No, it proves nothing of the sort, sorry. That is a delusion, which is convenient to believe, that is all.

In medical trials there are objective criteria which can be used to validate the results - various tests. DBTs in medicine are important and valid because the objective measurements and tests can be influenced by the placebo (i.e. psycho physiological) effects. But it is the objective result which matters. In audio DBT that concept is turned on its head - we are trying to use our conscious subjective perception to validate the differences which may influence us mostly on a subconscious level. And that is one (but not the only one) reason why audio DBT are extremely insensitive for what they try to achieve. And obviously it is very convenient for someone who wants a particular result to use a test which gives that result no matter what  .

Cheers

Alex

[oldway]

Nothing is more subjective and arbitrary than the appreciation of our hearing.

I would like to know the results of a test (which are the amplifiers that sound best ... give a rating of 0 to 10) made by a hundred of confirmed audiophiles (a hundred for the results to be statistically valid) who would give their opinion on a dozen different amplifiers they would only know by a number.

This test would take place in the same room, with the same sound source and with the same speakers. (and, of course, at the same power level)

The amplifiers would be in the "flat" position of the tone controls, no activated filters, and no loudness.

Would the opinions of these "specialists" be he same ?

In my opinion, they will certainly make a distinction between tube amplifiers (current driven loudspeakers) and transistor amplifiers (voltage driven loudspeakers), but that's all, no difference between high end transistor amplifiers and low end transistor amplifiers...

[Fungus]

YADA YADA

What on earth are you on about?

According to you, all HiFi systems sound the same, there's no possible way to classify them as "good" or "bad".

This is obviously, facepalmingly false. 

Or, if you accept that not all HiFis sound the same then AB tests must be possible and you're contradicting yourself.

[Alex Nikitin]

YADA YADA

What on earth are you on about?

According to you, all HiFi systems sound the same, there's no possible way to classify them as "good" or "bad".

This is obviously, facepalmingly false. 

Or, if you accept that not all HiFis sound the same then AB tests must be possible and you're contradicting yourself.

Nowhere I've said anything of that kind... . 

Cheers

Alex

[Beamin]

 

I kind of enjoy it when these threads get derailed I started the thread purposely with as little chance of this as possible but I am no closer to getting ideas on this question as when I asked it. Does anyone "hear" really know? Because if they don't the back and fourth is not valid; based on the fact that no one knows the answer to the technical difference that would make the sound difference. There is no "sound" argument to be made.

If someone did say "this" part/design makes "this" better then started saying why amps do/don't make a difference they would have a base to make their argument. At this point I see a lot of factless opinions and arguments based on really nothing. I guess this is why audio phoolerly is such a $$$ business. Even the technical people fall victim to it.

[Beamin]

I can hear the difference in 0.8THD and 0.03% with decent speakers. I don't think most people could though. I stay away from anything over 0.1% THD because you are not getting the full benefit of your speakers.

I very much doubt that. With a decent pair of headphones, you stand a chance, but not much, especially at your age.

What is my age? Do you knw why I bought a higher end amp and not a the  cheapest end amp or highest end? Because the ones cheaper then it didn't sound as good. The ones abouve it didn't sound any better but still better then the cheaper ones with the exception of Bose who has no mid bass or base. Once again how do you know that? Or are you just being contrary because you can't tell the difference and if you can't tell nobody can? High end speakers sound better then high end head phones. Why do you say that?

I don't know your exact age but, going from your other posts, I know you're not young, therefore you will have some age-related hearing loss, especially at high frequencies.

Did you subject yourself to a double blind listing test? I highly doubt it. Cognitive bias, aesthetics, size, cost,  can easily explain differences in perceived sound quality. No one is immune to this. The only way to be sure one can tell the difference is a double blind test, repeated enough times.

Headphones generally sound better than speakers, even cheap headphones vs high end speakers, because the ear is in the near field region, rather than the far field so it's easier to get a flat frequency response and reflections and absorption due to room acoustics are no longer factors.

Yes  next time I go to the speaker store I will hire scientists do set up a double blind placebo test with psychologists and statisticians to make sure the scientists have ruled out any hidden variables. This way it will ensure that my subjective taste in a 100% subjective matter is 100% sterilized and devoid of any emotional bias. I might end up getting a set that sound horrible to me but at least they were scientifically proven to be better. I will also have them build an anechoic chamber that is nothing like the room I will be using them in. Of course before I do any of this I will have an audiologist test my hearing to find out what I'm sensitive to when analyze the data from the acoustic scientists also to rule out hidden bias.

Do you ever think "Hey what I just wrote was completely ridiculous and would make no sense to the average ( a technically minded but practical) person reading it and is also TOTALLY impractical and would never happen".

Double blind placebo tests to go speaker shopping? Really? REALLY?
Totally ridiculous is an understatement and you are kind of embarrassing yourself especially if you start making replies doubling down on why your post is not ridiculous.. 

You buy what sounds good to you even if you are victim of audio phoolerly they still are what sounds good and you enjoy it.

There is no need for that attitude.

None of what you've said is scientific. It's all highly subjective. You can't be sure that you can actually tell the difference between 0.8% and 0.03% THD, because you've not proven you can.

I thought we were talking about amplifiers not speakers? Suppose two amplifiers, set to exactly the same volume, playing the same music, were connected to a pair of speakers, via a relay, to switch between the two amplifiers, controlled randomly by a computer. If you can tell which amplifier is driving the speakers, significantly beyond 50% of the time, then you've proven that the two amplifiers actually sound different to you. Whether or not you prefer the one with the better figures, is up to you.

Obviously you can't perform the test mentioned above in a Hi-Fi store and I never suggested it was, which was the point I was trying to make. You have many other factors, other than sound waves from the speakers, which influence your judgement, whether you like it or not. Some of these factors are important, when considering a purchase: aesthetics, ergonomics, build quality etc. but if you think you're basing your decision on sound quality, then you're kidding yourself. Someone else posted a very good video on the subject, but I can't find it.

Fortunately, modern, well-designed solid state amplifiers, are audibly transparent, i.e. no one will be able to tell the difference between them, in the above scenario, as long as they're not overdriven.

Apologies if I sounded crass. I get sensitized to the disconnect that people have to the real world on tech forums and erroneously grouped you in with them.

But seriously get a pair of decent speakers (not best buy brands mass produced Chinese import crap) and compare a Sony amp from best buy to a "good quality" amp from a hifi shop. In my case I used a Marantz I own and a 199$ Sony I borrowed from a friends living room. Maybe it wasn't the THD that I noticed; being that number is so small it could have been many other things but on the contrary that number is an order of magnitude difference between amps so it could be a contributor. I know audiophoolery is alive and well I am biased in that I consider myself educated in the issue and would be upset to learn I paid a lot more for something that was the same.

Points I considered that "Biased" my judgement:
Opening the amps up and seeing physically larger value parts such as caps and transformers. These parts are not cheap and add to the build cost substantially. If manufactures know their target audience will be overly critical of the sound quality they have to look out for this. Also when these factors are deep within the case and not advertised there is a reason why they put the extra money in other wise they are putting money into something that's not going to make a difference; which is a bad idea from a business point of view.
I hate getting "phooled" it would take a bit to prove to me I paid extra for the same performance but unlike most people I am very flexible and with sufficient evidence I do change my point of view. I rarely double down on things when there is evidence to the contrary. This is rather a reason to question your views.
Working in the business of audio when I was younger I found myself getting caught up in the BS they program into your head to make you sell more. Why teach a person to sell when you can sell them on the product? Then their recommendations come natural when they are selling to the customer and the worst sales person becomes an effective tool. Work for corporate America and you will notice the managers are always selling the employees on why their product is better if not best, even when it is shit. "We sell on value not price." Is code for we are ripping off the customer and charging more then our competition.

So I think there is a difference. I can hear it. And if I can hear it, it exists to me. And that's all that matters at the end of the day.

Also I don't like when people make generalizations about my age or other personal factors that I haven't openly revealed on the internet. So yes that triggered me into an overly aggressive response that wasn't warranted. Arrogantly I consider myself a bit of an enigma after hearing people say this to me. I rarely fit into a pattern or box and if you have me figured out you don't. I don't have me figured out. I have done so many 180's in life tht even my family realizes that anything is possible with me because I am so open to change. just my 0.02$

[Alex Nikitin]

I kind of enjoy it when these threads get derailed I started the thread purposely with as little chance of this as possible but I am no closer to getting ideas on this question as when I asked it. Does anyone "hear" really know? Because if they don't the back and fourth is not valid; based on the fact that no one knows the answer to the technical difference that would make the sound difference. There is no "sound" argument to be made.

If someone did say "this" part/design makes "this" better then started saying why amps do/don't make a difference they would have a base to make their argument. At this point I see a lot of factless opinions and arguments based on really nothing. I guess this is why audio phoolerly is such a $$$ business. Even the technical people fall victim to it.

What kind of an answer are you looking for? I did design many good amps, had my share of awards and reviews, took part in numerous Hi-Fi shows. I made all my designs so they sound right to my ear, hoping that at least some people will share that understanding of a good sound. At home I use a production amplifier that I've designed in 1996 (it was sold for about £300 retail then) without any changes and still happy with the sound it produces. I won't change it for any high-end amp. As one well known reviewer said in 1998 "The fact is, had a bought {this amplifier} 15 years ago, I might never have become an audiophile. Instead of thinking, Something's got to sound realer than this, I would have settled back in my listening chair and thought, Sounds about right. Now, were's that copy of Don Carlos?" There is no simple answer on how to make good amps. If I would try to share here some of my knowledge in that area, I will be ridiculed, I suppose (I've tried in that thread I've referenced earlier and got accused in making an art out of a simple engineering task  ).

Cheers

Alex

[oldway]

If you think one amplifier sound better than another, but you don't have any technical explanation why it is so and you can't measure nothing to proove it, as Dave use to say, it smell bullshit.

Reviews, Hi Fi shows and others are 99% marketing and commercial interests.
Some people are even trying to convince you to buy $300.000 speakers....

[Alex Nikitin]

Reviews, Hi Fi shows and others are 99% marketing and commercial interests.

There is that 1%  .

Cheers

Alex

[Loboscope]

If you can hear a difference of two amps (or any other technical gear in audio), you will measure the difference. If you cannot measure a difference, then there will be no difference and all your hearing was illusion.

Lots of scientific studies have been made in the field of hearing. And a healthy ear will indeed distinguish very tiny differences of delay time between the two ears, tone pitches and generally our ears are very sensitive with a great dynamic range between extremely quiet sounds and very loud noise.
But there are not only the ears, who are the receptors of the audible world around, but there is also a brain and its hearing areas. And the brain will always make its own interpretation of the neuronal information the ear brings to him. This is probably the greatest part of the work our brain does continuously: to sort and to interpret all the information our sensory organs bring to him.

And it is not difficult to consternate our brain and to let it misinterpret sensual informations. Probably the most perturbing factor are our expectations! We will hear and we will understand, smell and so on, what we expect to hear, to understand, to smell. There are also lots of investigations about this item.

So if you want to do some objective tests, you must eliminate all expectations as good as possible. Any scientific test design must have been done so. To test tone pitch differences or time delay differences it will be easy, because there is simply no expectation if the next tone presented will be lower of higher or will be heard coming from a certain direction.
But if you will see the brand name of the amp or/and its appearance will be impressive, you will expect it will sound better. Immediately and unconscious.
So only a double-blind-test will guarantee a certain level of objectiveness. DBT of cables always could reveal, that there will be absolutely no difference between ultra cheap and ultra expensive cinch-cables and microphone-cables for example.

I would say, that if an amp exceeds some certain thresholds in THD, Noise, IM, channel separation, flatness in frequency, frequency range and so on, it will sound very good. For example, if its noise-level will be around -90 dB, you will hear no noise when you hear music at normal sound level. If the noise level will be better, -100 or -110 dB, the amp will be better from its specs, but at normal sound level you will hear no difference in noise.

So if you will have to look for the quality of an amp, you will look for its specs and you must know, witch level the construction will exceed in all its details as minimum that all sorts of distortions will remain unaudible (at normal hearíng sound levels). Any sort of distortion beyond ca. -90 dB will not more audible for all I know.
Another criteria could be its robustness, capability of uninterrupted service, especially if the amp should be used for PA.

[trys]

And the balance setting, what is it for? 

I don't have a balance setting.  It's a stupid idea unless you are deliberately trying to correct for junky setup where some of the cheapest equipment today should be beyond the need of such correction.

There goes a person who wears out the floor / carpet / acoustic chamber for having to sit in absolutely precisely and exactly the correct spot to hear the music for himself only.

[DrGeoff]

And the balance setting, what is it for? 

I don't have a balance setting.  It's a stupid idea unless you are deliberately trying to correct for junky setup where some of the cheapest equipment today should be beyond the need of such correction.

There goes a person who wears out the floor / carpet / acoustic chamber for having to sit in absolutely precisely and exactly the correct spot to hear the music for himself only.

The preamp probably has no EQ either.
I remember those preamps from the 80's that had a single volume knob and input selector. Assuming that everyone was listening in a perfect room which does not exist.

[Alex Nikitin]

The preamp probably has no EQ either.
I remember those preamps from the 80's that had a single volume knob and input selector. Assuming that everyone was listening in a perfect room which does not exist.

If you need EQ your amp and speakers aren't good enough.

Cheers

Alex

[DrGeoff]

The preamp probably has no EQ either.
I remember those preamps from the 80's that had a single volume knob and input selector. Assuming that everyone was listening in a perfect room which does not exist.

If you need EQ your amp and speakers aren't good enough.

Cheers

Alex

That is complete and utter bollocks.

[Alex Nikitin]

The preamp probably has no EQ either.
I remember those preamps from the 80's that had a single volume knob and input selector. Assuming that everyone was listening in a perfect room which does not exist.

If you need EQ your amp and speakers aren't good enough.

Cheers

Alex

That is complete and utter bollocks.

I will politely disagree. One of my criteria of a good system that it should sound tonally balanced at any level. If you have a problem with the room you treat the room, EQ won't help. EQ is a band-aid for poor quality systems IMHO (OK, sometimes for poor quality recordings too).

Cheers

Alex

[Zero999]

The test seems to be perfectly valid.  I don't see how anyone from a scientific background can say otherwise. Arguments against this kind of test seem to be very similar to advocates of spiritual healing vs tried and tested medical treatments

Oh, a strictly necessary requirement to establish a base line of a test sensitivity (otherwise how we know what we testing) now suddenly becomes something mystical?! 

Cheers

Alex

Why is that necessary?

The test proves that human ear is insensitive to any differences between the amplifiers used in the test.

No, it proves nothing of the sort, sorry. That is a delusion, which is convenient to believe, that is all.

In medical trials there are objective criteria which can be used to validate the results - various tests. DBTs in medicine are important and valid because the objective measurements and tests can be influenced by the placebo (i.e. psycho physiological) effects. But it is the objective result which matters. In audio DBT that concept is turned on its head - we are trying to use our conscious subjective perception to validate the differences which may influence us mostly on a subconscious level. And that is one (but not the only one) reason why audio DBT are extremely insensitive for what they try to achieve. And obviously it is very convenient for someone who wants a particular result to use a test which gives that result no matter what  .

Cheers

Alex

No, amplifier test was designed to obtain an objective result: whether people can differentiate between the sound produced by three different amplifier designs, a new (at the time) solid state, an older solid state and a valve design. This is clearly stated at the start of the paper. Granted, asking them their preferences was subjective, but that was not the primary goal. The results of the tests, are objective, rather than subjective. They clearly show the three audio amplifiers are transparent to the human ear, which is what one would expect from a good amplifier design.

If one is to test amplifiers on sound alone, then one needs to eliminate any other differences, which would influence the audience's judgement, otherwise the test is pointless.

[BrianHG]

And the balance setting, what is it for? 

I don't have a balance setting.  It's a stupid idea unless you are deliberately trying to correct for junky setup where some of the cheapest equipment today should be beyond the need of such correction.

There goes a person who wears out the floor / carpet / acoustic chamber for having to sit in absolutely precisely and exactly the correct spot to hear the music for himself only.

   If I could afford the house and room to do so, just maybe....  For the times when I need such an experience, I just use headphones. 
But seriously, I have basic quality speakers and it doesn't matter where you are in the room, they don't need balance correction.  When playing a mono sound, the have a central sound filling the entire room.

[trys]

Mono.

[cdev]

Pros perform equalization of a sound setup when its installed in a space. The placement of speakers makes a dramatic difference in how they sound. So there is no such thing as a flat response.