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The famous AB test between amplifiers

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I just want to make it clear that listening to Chinese, Russians, Italians, etc., at first glance it seems that they have the same tone of voice
No, it really really doesn't.

I've worked with Russions, Chinese, Italians. Also Germans, Swedes, Norwegians, Americans, Spanish - probably some other nationalities. My first thought has never been "they all sound the same"

I"ve been sat in an office in China, and have easily been able to pick out the voices of the people I worked with even when I couldn't see them AND they were speaking chinese. Similarly in non video tele conferences. Including with 3 or more different nationalities on the call. Also easy to pick out voices I didn't know - and how many there were, so I could sort out introductions.
 

Rob :)
I have read the article and it seems logical, an amplifier can sound the same as another with different features if you modify it and if you do not modify it you can find differences.
 
The other issue is that the A/B test is at a fixed volume, but normally you listen to a system by turning the volume knob up and down, this is where even though the amplifiers have the same power they will differ if for example they have different power supplies, this is when they start to lose linearity at some frequencies and you start to hear something different.
 
The other issue is that the A/B test is at a fixed volume,
Doesn't have to be... use a source with volume control (DAC) or use a pre-amp.

When you drive amps outside of the capabilities of at least one of them.... sure you can hear (and measure) differences.
When 2 amps are measurably different (that audible thresholds are reached) then yes they can be told apart.

So... audible thresholds, transducer quality, training, music used and recording quality also matter.
2 Amps differing less than audible thresholds can not be told apart in a properly conducted blind test.
 
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The other issue is that the A/B test is at a fixed volume, but normally you listen to a system by turning the volume knob up and down, this is where even though the amplifiers have the same power they will differ if for example they have different power supplies, this is when they start to lose linearity at some frequencies and you start to hear something different.
What levels are you listening at to tax your amps this much?
 
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The other issue is that the A/B test is at a fixed volume, but normally you listen to a system by turning the volume knob up and down, this is where even though the amplifiers have the same power they will differ if for example they have different power supplies, this is when they start to lose linearity at some frequencies and you start to hear something different.

If you drive an amp until it 'loses linearity' then, yeah, duh, it can sound different from another amp that is designed to stay linear at that level.

No one claims otherwise.
 
I have read the article and it seems logical, an amplifier can sound the same as another with different features if you modify it and if you do not modify it you can find differences.
Here is the thing. Bob Carver was a showman (and a good engineer). His amps stock were indistinguishable from the much more expensive gear we sold (in the '80s I worked in a store in Seattle that sold Levinson, Goldmund, Accuphase, Audio Research, and Carver to name a few). Bob regularly came down from Lynnwood to demo his gear in our store. Nobody in the store could tell his amps from any of the other amps unless you did something like comparing a Carver vs. an Audio Research on a pair of Infinity Kappas or a pair of Apogees. In that case the Audio Research would struggle audibly because it couldn't handle the load while those old Carvers could. Regular speakers were indistinguishable between all of these amps. Even a Niles installation amplifier was indistinguishable unless you made the comparison on a speaker that taxed the amp it was being compared to (those old Niles were awesome, I still have one that I use for speaker development.) The punch line of the challenge is this line from the Stereophile article:
We made no effort to do A/B testing, since we feel it does not replicate normal listening conditions
Bob took an amp that was indistinguishable in a level-matched test, exposed the listening panel to the amps in non-level-matched conditions were everybody could clearly hear a difference (due to the different levels), went behind his magic curtain and level matched the amps, came back and got everybody to agree (sighted) they sounded the same. Every trick in the book was used here, the Carver Challenge is an enduring myth. Welcome to the HiFi carnival. I would like to help you avoid the pitfalls of the industry, but don't have much faith at this point.
 
The other issue is that the A/B test is at a fixed volume, but normally you listen to a system by turning the volume knob up and down, this is where even though the amplifiers have the same power they will differ if for example they have different power supplies, this is when they start to lose linearity at some frequencies and you start to hear something different.
You are still fundamentally misunderstanding the test procedure.
If you want to try different volumes, repeat the test at a variety volumes, matching amp outputs at each different volume, avoiding driving either amp into clipping.
It's unfortunate you have never done this properly. It does hurt the ego when we find out our hearing isn't what we thought it was. ;)
There are so many additional tests that you can take to investigate the limits of your hearing. Klippel has some that will illuminate just how much distortion you can actual perceive. It's quite large, which you should be thankful for since speakers have surprisingly high distortion yet still sound good. This is despite the distortion being way more than any reasonably well designed amp.
I can link you to some tests, they are online, apply controls (no peeking!), can be done in privacy, with your favorite speakers and/or headphones, at any volume you wish. You will be stunned by the results. And it is useful information to help you understand what can and can't be heard, since the theme of the luxury HiFi industry is to get you to perceive differences even if not present, and monetize that perception.
 
The issue with the rapid switching between amplifiers is what I question with the famous A/B test, with these tests you do not give the brain the opportunity to process and memorize the differences between amplifiers if there are any.
Speak for yourself, everybody else has enough time to process and memorize the difference, seems to say something about you. Im done with this.
 
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Speak for yourself, everybody else has enough time to process and memorize the difference
I think it’s more like: If you can’t hear a difference in AB testing, the test methodology is probably flawed.

… the only thing flawed here is the logic.
 
They sound almost the same but the difference is in the mids, which with the MC611 sound a little softer and less cold than with the HK990, this is a little noticeable in the roughness of the voice.

You replaced a 3k€ amp with 23k€ of monobloc amps and they sound almost the same (and we're not even completely sure there is any difference). Interesting.
 
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Speak for yourself, everybody else has enough time to process and memorize the difference, seems to say something about you. Im done with this.
good for you, if you have finished excellent you should no longer comment on this topic
 
Why do you need an analogy to begin with? Analogies are like slivers of a broken mirror...


JSmith
An analogy is needed because you are involving a variant that is perception, it's that simple.
 
An analogy is needed because you are involving a variant that is perception, it's that simple.
There are scientific means to deal with perception. Analogies not required. It's that simple.
 
You replaced a 3k€ amp with 23k€ of monobloc amps and they sound almost the same (and we're not even completely sure there is any difference). Interesting.
Well, you didn't ask me why I replaced it, you didn't ask me if I had problems with the hk990 software, you didn't ask me if you've always wanted to have a Macintosh, you didn't ask me if I like the aesthetics, you didn't ask me if I really needed more power than 300 rms per channel, you didn't ask me if I wanted to pay more to have better dynamics, you didn't ask me if I found a good one.

If you ask me if I found a difference, yes there was, more natural mids, more linearity when lowering and raising volume and one thing I love is high spl for short periods, using 700 rms per channel is something delicious.
In many areas the gain in benefit vs cost is exponential. People who like cars put 15k in their suspension to gain half a second and they are happy.
 
There are scientific means to deal with perception. Analogies not required. It's that simple.
You are letting yourself be carried away by 100% science.How can you scientifically prove whether I like you or not as a person?
 
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You are letting yourself be carried away by 100% science. How can you scientifically prove to me whether I like or dislike you as a person?
:facepalm::rolleyes:
 
Here is the thing. Bob Carver was a showman (and a good engineer). His amps stock were indistinguishable from the much more expensive gear we sold (in the '80s I worked in a store in Seattle that sold Levinson, Goldmund, Accuphase, Audio Research, and Carver to name a few). Bob regularly came down from Lynnwood to demo his gear in our store. Nobody in the store could tell his amps from any of the other amps unless you did something like comparing a Carver vs. an Audio Research on a pair of Infinity Kappas or a pair of Apogees. In that case the Audio Research would struggle audibly because it couldn't handle the load while those old Carvers could. Regular speakers were indistinguishable between all of these amps. Even a Niles installation amplifier was indistinguishable unless you made the comparison on a speaker that taxed the amp it was being compared to (those old Niles were awesome, I still have one that I use for speaker development.) The punch line of the challenge is this line from the Stereophile article:

Bob took an amp that was indistinguishable in a level-matched test, exposed the listening panel to the amps in non-level-matched conditions were everybody could clearly hear a difference (due to the different levels), went behind his magic curtain and level matched the amps, came back and got everybody to agree (sighted) they sounded the same. Every trick in the book was used here, the Carver Challenge is an enduring myth. Welcome to the HiFi carnival. I would like to help you avoid the pitfalls of the industry, but don't have much faith at this point.
From what you say, it seems to me that this man was able to make amplifiers and modify them to the point that they rivaled the most expensive ones, I suppose he was even able to copy their sound in some way. Now if you put them both in an A/B test and they sound the same, maybe that's because it is like that.
What I don't agree with is that we take a simple electronics amplifier x and want to compare it with an excellently built one and expect the same results (normally the better built one will sound better)
 
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