Is 2 channelAmp about the same as reciever? - Page 5

Vitaminc, can you give an example for when you say, "The measurable differences within hearing frequencies are audible."?

I'm leery of a German that appeals to emotion in an attempt to debunk science. History has something to teach us about that.

The guy basically tells us he likes lots of added second harmonics, a rolled off high end and near field bass without any real low end. That's cool, as long as he also points that out in his reviews. The fact that he thinks this makes objective measurements less useful doesn't follow from the rest of his arguments; he should instead realize that he can use such measurements to find amplifiers (other than single ended triodes) that meet his requirements.

I'm agreeing with the statement, not to the challenge.

Figures...


Guess that's a good thing though!

I don't think that "all amps sound the same," because I don't think that modern amplifiers used within their tolerances and not driven to distortion have a "sound" at all. The "sound" is the product of the system, which includes your central nervous system. And even if the amp had some effect on the "sound," it's effect is going to be orders of magnitude less than the rest of the system (including the listener's biases) and I'd challenge anyone to consistently discern the difference between two amplifiers, level matched, in a blinded test (with the capability of switching instantly between the two amplification sources) with anything approaching statistical significance.

You sound like Julian Hirsch reincarnate. Is there blind testing in heaven?
All kidding aside, blind testing has its faults. I think the truth is somewhere in the middle.

That may be.

I wonder where the middle would be. The argument is scientific testing vs. perceptual hearing. Either you do it one way or the other. Either you accept scientific test results or you don't. Hard to imagine a middle ground.

FMW, I think what the poster was getting at with respect to "Middle Ground" was the level / amount of psychoacoustics that one allows into the equation.

So, that's how I took it.

That's like asking how much biology one should "allow into" the practice of medicine.

A good portion of the United States population doesn't believe in evolution. We shouldn't be surprised that roughly the same portion doesn't believe in scientific testing applied to audio equipment.

We're just talking about audible differences. Bias controlled testing will reveal whether or not audible differences exist. They won't put a number on them or give any value to the differences - non-existent to subtle to obvious. So I suppose that's a middle ground. But when it comes to determining whether or not there is an audible difference, I don't think there is a middle ground at all. It's black or white. Either there is an audible difference or there isn't.

I think there may be a middle ground. It may be the case that two different amplifiers change the sound of a system in two different ways, but that a subject cannot reliably identify that difference in a reproducible way. Another middle ground is that all amplifiers behave differently, but that the differences are so slight as to have only a very subtle effect on overall performance (subtle enough to not be identifiable any often than by mere chance).

What the hell am I talking about? I need sleep...

In the end, enjoy your gear and be happy with your choices.

Exactly.

True. Also consider that blind testing may not be a good method of evaluating audio components because listening fatigue quickly sets in and obscures any differences. Also, you may need to evaluate for a longer period of time to assess the true nature. Take a girl out for a first date but only for 30 seconds and you may not experience enough to get a proper evaluation of her characteristics although you might be able to evaluate superficial things like looks, wealth, etc. Thirdly, some listeners just aren't experienced enough or talented enough to tell the difference. There is nothing wrong with this and these people will be happy with Walmart rack systems for $199. As the cost/complexity/resolution of speaker systems increase, their interraction with the amplifier can be more unpredictable. So although it may be difficult to hear the difference between a Sony receiver and a Krell on $100 Walmart speakers the differences will become apparent to most when driving $20,000 speakers that present difficult loads. This doesn't mean that everyone should spend big bucks on an amp. Many will find happiness at $500, $1000, etc. but you have to choose carefully, evaluate within YOUR OWN SYSTEM, not the dealers and hopefully get something capable of driving some difficult speaker loads, which eliminates most modern receivers (but not all) from the list.

Listener fatigue is possible (though why it should only affect DBTs is a mystery). But long-term "evaluation" has been shown to be less sensitive to subtle differences than a short-term test.


This is absolutely true, but it's nothing to do with DBTs. If you don't know what to listen for, you aren't going to hear it, no matter how you listen.


An amplifier's interaction with a speaker is quite predictable. A human being's reaction to a sound, much less so. In fact, a human will not react consistently to the same sound, which is what makes subjective evaluation so tricky.

It is the only accurate method we have so that, if it is a poor method, then there is no good method. We know beyond a shadow of a doubt that sighted testing is unreliable. Flat out proven. Period.


It does take some time for a listener to become accustomed to a sonic presentation and experience has shown that familarity breeds happiness with audio components. However, it is useless to attempt to compare subtle sonic differences over periods of time more than a few minutes because our brains can't remember them much longer.

We tested this once with two pairs of B&W 801 speaker systems. The purpose of the test was to see if speakers break in or change their sound after a period of time. The dealer was setting up a new pair of 801's in his listening room. One of our group brought a pair that he had been using for almost two years. We did our usual bias controlled listening tests and found no sonic difference between them. That says something positive about B&W's quality control to be sure. The owner of the used pair of 801's was dead certain that they had "mellowed" with age. Luckily for him, they had not.


Thanks but this is non sequitur. Evaluating human compatibility and subtle audible differences in sound have nothing to do with each other.



I believe the opposite is true.


Again, non sequitur. If you judge sound from different speaker systems, that doesn't say anything at all about the how the amps sound. When we did our amplifer tests several years ago a 200 wpc Class A Krell was one of the subjects of the test. It sounded exactly the same as all the other solid state amps we tested that weekend. There was no Walmart product but there was a $150 Onkyo receiver as one of the test subjects. They were both tested driving B&W Matrix 802 speakers. That is good news, by the way. The object of amplifier design is to increase the amplitude of the waveforms without changing their shape. All the solid state amps and one of the tube amps did that.

Yes the Krell would be able to drive low impedance speakers louder than the Onkyo receiver, no doubt about that. But the sound was the same when both amps were working under conditions within their design parameters. Our issues have been about audibility, not low impedance performance. Nobody is arguing about low impedance performance.


No argument there.

I don't agree.

But...

You may have just made a good case for buying a $500 amp versus a $5000 amp: after a few minutes, I just doesn't matter.