Author Topic: Richard Clark $10,000 Amplifier Challenge  (Read 4107 times)

Offline Emil

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Richard Clark $10,000 Amplifier Challenge
« on: May 23, 2017, 10:43:28 AM »
Anyone familiar with this?
I remember the Stereophiel challenge with Bob Carver and the cable challenge with James Randi

http://tom-morrow-land.com/tests/ampchall/
"Today I didn't even have to use my A.K.
I got to say it was a good day"
    --Ice Cube

Offline richidoo

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Re: Richard Clark $10,000 Amplifier Challenge
« Reply #1 on: May 23, 2017, 02:07:48 PM »
My mastering engineer told me about this 10 years ago when I told him I got new tube amps. I said they are very low distortion for tubes. He said tubes are for adding distortion.  I said "oh" and left it at that.

Offline steve

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Re: Richard Clark $10,000 Amplifier Challenge
« Reply #2 on: May 27, 2017, 03:56:50 PM »
Anyone familiar with this?
I remember the Stereophiel challenge with Bob Carver and the cable challenge with James Randi

http://tom-morrow-land.com/tests/ampchall/

I remember Emil. Of course no one will pass this kind of test. Reminds me of the magic rocks test. Either the author is ignorant, or a skillful marketer. $200/per, and several thousand, he has grossed what, more than 1/2 million dollars.

What the public does not understand is that he is holding all the cards, whether he knows it or not. Let's go step by step.

1. First we need proof that a dbt/abx test equates to normal listening. If not, we are comparing apples to oranges. I have never seen any proof, and he did not provide any.

By the way, the burden of proof is upon him/his friends, not the other way around. The Confound Variables of, say computer programming and audio, are totally different.

The key to effectively performing, and public understanding a proper listening test include:

A. Knowing/understanding the Confound Variables (CV) and how to address them, not just one, Sight. As we shall see below, the testing will be skewed towards no sonic difference if we do not address even one CV.

B. Understanding Methodologies, and how results can be skewed towards no sonic difference.

We see audio books, websites, forums that suggest we, the public, perform dbt/abx tests. How is the public to know/understand and address CVs, and know/understand the Methodologies that skews the test? The normal, average public won't. Thus the public will use methods that skew towards no sonic difference without even realizing it. And that is what happens in the abx test according to the article.

2. Notice the article mentions no CVs, except sight.
Leaving out CVs will skew the test towards as it desensitizes the "ear".

     a. Habituation to Stimuli occurs when we repeat selections. At first we can differentiate sonic differences, but differences quickly disappear. It only takes 2 ABs before the differences start to disappear.

So if we have 12 ABs in close time, guess what........ Just one CV not addressed, Habituation to Stimuli, and we have skewed the test towards no sonic difference. Remember, the author's own words, it takes 22 out of 24 correct identifications to be significant.

     b. One better be in the sweet spot. Why? Rooms have nodes, example bass nodes, which includes physical area. Sit in a position where bass node is increasing, masking of inner detail increases, less differences between components. With 22 of 24 to be significant, the odds of statistical perceptible differences in this kind of test are virtually zero.

     c. Cochlea Fatigue ("ear tiredness") is the condition of desensitizing due to continuous activity utilizing the ear. The more repetitions of the same selections, the more cochlea fatigue, thus skewing the results towards no sonic difference.

3. SPL. The louder the selections, the increase in cochlea fatigue.

4. The quality of selections used. Some selections contain more  musical information in the mid range, where the ear is most sensitive. Playback a pipe organ and perceptible changes are not as noticeable as playback a sax, trumpet, percussion, clarinet etc, with much more midrange expression.

Another example of masking is midrange music with lots of bass, or with heavy ambience added.  

A classic example is the Stereophile gathering with John Atkinson and a computer programmer Arny Krueger. "The Great Debate".

https://www.stereophile.com/news/050905debate/index.html

Here is a quote from Arny Krueger.
Quote
Arny claimed that he can "knock off" 16 foolproof trials in a few minutes by playing specific predetermined sounds rather than music.

Notice Arny, by his own admission, did not address point 3, a CV  called Habituation to Stimuli.

Quote
Krueger distributes an ABX Comparator program that enables you to conduct what he considers foolproof ABX tests in the privacy of your own home.

According to the above, Arny does not even consider other CVs, and cannot provide correct instructions on testing.

5. Component quality. Debatable some claim. What is not in doubt is the difference in internal structure of parts, thus different internal resistances/impedances, inductances, capacitances etc.  

6. Testophobia, actually exists. Being scared affects numerous aspects of brain function. Even Nova has had programs concerning flight and fight and its affects on testing.

In the link above, John A. has more points. The list goes on, and the abx tester mentions none of them.

"Testing Procedure", none. Do whatever you want. Violates nearly all the above points.

Testing stringent enough?
Quote
Yes. Richard Clark intentionally made the requirements strict because with thousands of people taking the test, even random guessing would eventually cause someone to pass the test if the bar was set low.


Would you want to lose $10,000? The challengers never had a chance with the test methodology and CVs not addressed. I wonder how many would want their money back?

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When purchasing an amplifier, they can ignore the subjective sound quality claims of marketers.

http://tom-morrow-land.com/tests/ampchall/rccomments.htm

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guys my testing procedures are more than fair
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and if you think you can do it then come on and prove it and stop talking about it
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all I ever said was that WHEN THEY ARE COMPARED EVENLY THE SONIC DIFFERENCES BETWEEN AMPLIFIERS IS BELOW THE AUDIBLE THRESHOLD OF HUMAN HEARING
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Blkout---tube amps are a serious waste of money--an obsolete technology like wooden wheels and horse drawn buggys-i can make any good quality solid state amp sound exactly like a tube amp with less than 5 dollars worth of parts---i have done it on many ocaasions for my amp challenge

Really? Leave out all the VCs, methodology, and then claims his testing is fair/accurate? Tube amps are waste of money. Wow.

I could probably come up with more, but I think you get the picture. In nearly 100% of tests, the CVs are not even mentioned, let alone addressed.

If this post is too much, moderator, please delete it as I don't want any trouble.

Cheers
Steve
« Last Edit: May 27, 2017, 04:21:26 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
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