The Richard Clark "all amps sounds the same" test

Hi Fi Choice Magazine has run blind,level matched group tests of all types of equipment including amplifiers over many years.All those results and scores are available.And yes there are obvious sound quality differences.

Peter Walker was asked if he ever listened to his amps during  development. He replied "No, because we already know when we design them how they will sound." This coming from one of the real pioneers of HiFi sound!

This is an old thread but I will mention a test done in the UK years ago by Peter Walker of Quad fame. He used a listening panel of British hi-fi magazine reviewers to compare the sound of two amps - a Quad II tube amp and a Quad 405. Speakers were the Quad 63's. Signal source was open-reel tape dubs from EMI master tapes. Both the tube and solid state amp were operated below clipping. The result: the esteemed hi-fi veteran listeners could not tell the two amps apart! I found this in a back issue of HiFi News & Record Review.

"Well, 2 reasons. I don't know if the offer still stands, but he offers $10,000 to anyone who can pass his test.

If you win you can buy an amp with that money :)."

Funny, with $10k you can buy "an" amp. How out of touch we are with reality in this crazy hobby.

Joemazzaglia, you nailed it buddy! If you intentionally cripple your system by removing the conditions under which it sounds it's best is an exercise for morons.

Yes, 'under a given set of conditions' for example if you are dead, its hard to tell two amps apart. Is he a zombie?

You'll never win a contest or bet against Richard. Period.

Of course amps sound different. But put RC at the controls, and let the abra~cadabra begin.

I lived right by Autosound2000, and dealt with him several times. He is in a class by himelf.

Much of what he states is true. Under "a given set" of conditions, ALL amps will sound the same.

The same is true with cars. Under "a given set of conditions" you could not tell the difference between a Hyundai SUV and a Hummer. Those would be some seriously strict conditions, however.

-jm

Why should I spend thousands of dollars for a "better" amp based on perceptions that are so ephemeral and delicate that simply testing them destroys them?
I have noticed that the arguments against double-blind listening tests are identical to those against such testing for the efficacy of prayer, the existence of teleportation, or the value of water-witching.
I believe the word for believing one's perceptions to be the best truth is "solipsism."
My favorite saying is : "Don't believe everything you think."

08-18-09: Rpfef
Personally, I would love to be able to take part in a fair double blind comparison. I do believe double blind tests are by far the best way to get at the truth of our own perceptions. ... What I want to find out is if my perceptions are to be trusted.

Maybe your perceptions are to be trusted, and double-blind tests applied to audio are what is untrustworthy.

Double-blind tests in medicine are passive. They measure what happens *to* you. Double-blind tests in audio attempt to determine what you can perceive in an interactive activity under rigid test conditions--an activity normally done for pleasure and/or relaxation.

To me, even if you flunked a double-blind test in audio, it doesn't mean your perceptions are untrustworthy; it may only mean that your perceptions are diluted or masked by the test conditions--or your interaction with the test conditions--themselves.

Personally, I would love to be able to take part in a fair double blind comparison. I do believe double blind tests are by far the best way to get at the truth of our own perceptions.
But to be effective in approaching that truth, I would want the comparison to be between amps I am already familiar with and which I already believe sound different. What I want to find out is if my perceptions are to be trusted.
Even though I hear, for instance, my Plinius amp as sounding identifiably different from, for instance, the Bedini of identical power it replaced, I am never certain that the differences I believe I hear are not mental constructs of the non-blinded situation combined with my own mental processes.
The program material must be familiar, also. All this is because the hypothesis being tested is: The Plinius 100 sounds identifiably unlike the Bedini Classic 100. That is the premise on which I am basing my purchase choices.
As a sworn skeptic, I want some better evidence of these phenomena than personal testimony or my own perceptions.

Using familiar gear, rather than strangers, means I have a ready yardstick by which to measure my results. I don't care what Richard Clark thinks. I just want to come closer to knowing whether I am fooling myself. After all, a lot of money is at stake: the thousands I spend on "better" equipment.

Setting up a double blind test in one's own room would be the ideal for this kind of experiment. Now that i have thought of this, I will perhaps try somehow to set one up. Obviously, if I do not score well, I will feel the test has exposed my prior self-deception. But, if I do well, I really will not be sure of anything because a really solid double blind test is pretty much impossible in my house.
Program material, also, would need to be familiar, for the same reasons.

Jult52, actually it's the Shostakovich 7th that is the Lenningrad Symphony. The 8th as I recall was generally about the horror of that war; the government called it the Stalingrad Symphony, but I don't think Shostakovich had any one battle of the war in mind.

As far as the thread goes, I'm not sure given Clark's requirements I could detect a difference, certainly not 24 out of 24.

I just added a B&K power amp to a Rotel integrated (so the Rotel went from functioning as an integrated to just as a pre-) and I found differences in key areas, using the same CDs at the same volume (I am careful about listening to music at pretty much only two gain levels). Many positive changes but one I found was that the Rotel integrated set-up actually produced a smoother midrange string sound. Post the change-up, the string sound was "coarser", without any changes to volume, range and dynamic peaks. I am very suspicious about Clark's test, even accepting his parameters, given my experience.

BTW, the Shostakovich 8th describes the awful siege of Leningrad, not the battle of Stalingrad.

hi drubin:

tou posed a (hypothetical) challenge on 8/01/08. i apologize for not answering:

here is my answer;

you can not prove the null hypothesis. this means that you cannot prove the hypothesis :

all amplifiers sound the same

ignoring the practicality of all combinations of pairs of amplifiers, induction is not definitive or absolute proof.

the exception can disprove the rule.

after doing n blind tests and, say, hearing no differences between two amplifiers, you may hear a difference in test n+1.

lightminer:

what i have stated attests to the futility of testing amplifiers. as many amps as you test, it may be possible to hear differences between a pair of amps, yet to be tested.

My guess is all these tests were done transistor vs transistor- I'm pretty sure I'd be hard pressed to accurately tell the difference.

I agree - I would suspect the majority of high end car amplifiers are soild state - I would imagine microphonics from vibration might pose a problem with a tube application in that context.

Indeed I was careful to mention "solid state" in my previous remark, as I think you can hear a tube versus SS more easily, especially those with an output transformer - so it would be incorrect to say everything sounds the same. You would indeed be more likely to find slight variations in tube amps due to the voltage paradigm and choice of output transformer (as well as topologies). However, frankly speaking, the test (as described) seems to try to minimize all these aspects too. In short, by limiting amplifier operating range to extremely modest levels (which avoids where most large differences might show up), careful volume level matching, and by trying to compensate for the voltage paradigm through the addition of resistors - it is hardly suprising that remaining differences would pose a challenge to even a discerning listener to score so highly (as Richard requires) when listening to music.

Lightminer, here is something else to consider:

http://www.atma-sphere.com/papers/paradigm_paper2.html

IOW, a speaker that is designed for transistors may not work with tubes without tonal anomalies, and I for one (if doing the test) would insist on one of our amps against his transistor 'control sample'.

In order to do that, its likely that the tube amp should be on a speaker designed for tubes.

I don't know how you could conduct a valid test unless you had a at the very least a speaker that was equally friendly to tubes as it is to transistors. My guess is all these tests were done transistor vs transistor- I'm pretty sure I'd be hard pressed to accurately tell the difference.

Johnnyb53, Shostikovich is my most revered composer. I use every bit of my Krell's 400watts into my 4ohm MG3.6R's...but they sound so sweet:O)

I am surprised that this is not generally accepted. My experience is that most good solid state amplifiers which are operated well within their capability (no clipping - i.e. at very modest levels) do sound quite close to eachother - much closer than different speakers. I for one would not be confident enough to pass a test unless it was with a test signal. I don't mean to say amps do not have their flavors - they do but it is definitely, for the most part, what I would call subtle.

In that sense, Richard's test proves nothing to me.

Of course, there are lots of very good reasons to own a high quality amplifier...good music is dynamic, extremely dynamic and it is at those extremes that great amplifiers can and do make a HUGE difference (low and high output levels)...if you want percussion or large band orchestral done well at realistic levels without sounding horrible and harsh then the highest quality amp makes ALL the difference.

Douglas - great last post.

Atma - hadn't heard he refused to pay, would be interesting to see more on that, and who finally broke the test!! If it was a regular Joe, magazine reviewer, or just snobby audiophile like us :).

To the equipment switching issue: I know for a while Stereophile was using the Mark Levinson 320S for various comparisons because it has the ability to somehow level match per input, I don't know the exact details, but that wasn't a cheap pre at retail! (And one I strongly considered getting before getting a Supratek. And while I'm off topic the Joule Electra line pre looks amazing...) My understanding is that the guy has a recording engineering or electronics background and part of the thing per the link above is that he runs the amps under 2% THD, so for some on electrostatics that may be 60 db :), but just to say he has equipment to measure THD and all kinds of little doo-dads, and high quality switching stuff - but that is all conjecture as I haven't seen any of it. Completely agreed that how you switch will matter, and if sound is degraded - on earbuds CD ripped Flac and apple lossless sound the same, so agreed that if one part of the chain is low-level differences will be minimized.

To some comments just above about car audio - I have felt that some high end car audio has extremely good dynamics as far as comparing to home audio - that is one area where car audio does really well.

For people just reading to the end my personal conclusions is that you have to look at his constraints really really carefully. Under his constraints I think he might be right. But then if you look at his constraints and consider driving a large electrostatic speaker to concert levels, then his constraints take away some of the most imoprtant differences bewteen amps. I decided that I might very well fail his test between the Sherwood receiver I found that claims 4 ohms capability and was like $75 bucks and a Nelson Pass pure Class A 150-lb dual pair of monoblocks because under his test criteria we may not get over 55 db.

Part of his point is that amps do a particular thing, and he can eq all the 'warmth' and stuff like that out of them, he seems to think he knows precisely what an amp does and that it doesn't effect things like soundstage or some of the other 'qualities' that we ascribe to all audio equipment. He does agree that speakers, CD Players, etc., even pre-amps make a difference, but he is making a claim just about how amplifiers work, by degree from a scientific perspective, that they do one thing only, and that one thing shouldn't have an effect on some of the fuzzier criteria we ascribe to audio equipment - *and to which he does ascribe to other pieces in the chain*.

Also - everyone here - this makes me think that Parc may really be on to something. In Photography there are programs that can make digital images sort of look like various film emulsions like Velvia or Kodachrome (for those not in photograpy, films with very particular characteristics) - maybe Parc could add to its system a setting for 'mimic tube amp', 'mimic solid state amp', etc. As it is it allows for tons of adjustments that are sort of along the lines of what they guy here seems to be doing.

Parc is high quality analogue, and me with my supratek I'm not going digital pre anytime soon, but the other thing this makes me think of is some basically 99.9999% lossless Parc device embedded in a megabuck DAC/CD/digitalPre that does everything once in the digital domain and then *once* and once only goes from digital to analogue to the amp. Esoteric, EmmLabs, Meridian, Berkeley, Levinson etc. kind of companies, they could put out something like that.

Parc should 'lease' their technology for digital embedding in the total digital side just as chip companies like Burr Brown, etc. sells DAC chips to these companies and they would make money there and from the customization/consulting they do.

So one of the biggest conclusions I'm coming to from thinking through the Richard Clarke stuff is that Parc, and perhaps digital eq embedded early in the chain, might have a strong future in Audiophile land...

All amps do sound the same... underwater.

Yep i do. i've had two great alpine car systems, one of which would play a dave brubeck at carneguie hall cd so much better than my $3000 cd player into leak tl12+'s and stacked quad57's. go figure!

What's interersting to note here is that this is the same Richard Clark of car audio fame. I followed him back in the 80s from his Cadillac sedan deville to his Buick Grand National. Simply put, two of the best car audio systems I have ever heard, and better than many home systems.

But what I'm getting at is the fact that he chose expensive Alpine electronics for his show car. Surely if he believed all amplifiers working within their power bands sounded the same, he could have achieved the same results with, oh say, Pyramid (low level chinese made) amps instead. But all the stuff in his car from the head unit on back was pricey, boutique electronics. Anybody see what I'm saying?

Shakey

And all cars drive the same, all toilet paper wipes the same, all wine tastes the same. If you can't hear/feel a difference, it doesn't bother me. Your test is a total waste of time IMO.

Lightminer, I read somewhere that Richard Clark refused to pay up when the conditions of his test were met. Do you know anything about that?

I also understand that there remain some validity issues relating to the signal source hookup as well as the means to switch between the amps. The saying is 'garbage in garbage out'- the test will be impaired if proper attention is not paid to correct inputs and outputs. IOW, it is not possible to switch back and forth on the fly since the connections in such a scenario will be severely degraded.

cool post Lightminer, here is my take

The circumstances for a controlled experiment (in this case) is very unrealistic. As much as one tries to equate the comparative amplifiers, there is now way that setup will be truly equal in ALL respects. Here, inherently is the problem of this experiment. If there were a way to definitively control these variables (and yes, there are some very minute variables expressed, but none the less) then this would be a great experiment in every aspect of its intent. Personally, I have heard tremendous differences between amplifiers that I own. Granted, this was not under an extremely controlled scenario.

Cheers

08-12-09: Lightminer
MrTennis and Atmasphere - give the guy a call. Here is one page with the info.
Win the jackpot that a couple thousand people haven't won of $10,000 that he
offers for winning!

One year later and you still seem to
confuse us with someone who:
1) gives a $#!+, and
2) is stupid enough to pay $200 to play a parlor trick.

I had a Carver TFM 25 since '91. Last year I bought a B&K ref 202.2. The difference seemed subtle at first. I left the B&K in my system for a few months. I put the Carver back in because I sold it and the guy wanted to here it first. It sounded awful compared to the B&K. Bad enough in fact that my wife, who was in another room, came in and said "what happened to your stereo?".

MrTennis and Atmasphere - give the guy a call. Here is one page with the info. Win the jackpot that a couple thousand people haven't won of $10,000 that he offers for winning!

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

But note that some of the things you mention (high frequency content; the sense of 'brightness') are things he will make equal with his eq, no?

The soundstage and attack (and perhaps decay as well?) - those are the places you might get it right. If you do give it a try I've heard from reading the threads about it that tracks with lots of voices tend to score higher, so include some voice stuff. But be confident, he charges 200 to take the test to limit serious requests. :)

Mrtennis is right in his bottom line, and I can add to it: even if you add EQ to make a tube amp and solid state amp 'sound the same' isn't there a tacit admission there that they don't? Huh? I'm sorry, but in this case Mr. Clark has fooled himself silly.

Different amps in fact sound different. Here are the areas to look in which you will find immediately apparent, very audible differences: the differences between tube and transistor, within one camp of expertise, the difference between a class A amplifier and one that is not, and finally the difference between a zero feedback amplifier and one that uses feedback.

Areas to be sensitive to as you audition these amps: high frequency content; the sense of 'brightness' (even though all the amps might have the same bandwidth), differences in soundstage presentation (currently not a measurable quantity), presentation of the attack of the various instruments, smoothness as opposed to harshness, that sort of thing.

I could forecast some of the results but that might take the fun out of it for you :)

Soundlab or Magnaplanar 20.1- either is fine.

the alleged differneces between amps , following the restrictions established by mr clark, are irrelevant with respect to purchasing an amplifier.

if i am considering two amplifiers, a conrad johnson mv 125 adn some current solid state amp, i believe i will prefer one over the other all of the time.

in this case it is possible that the cj amp does not meet the criteria for a fair comparison.

it doesn't matter, because i would use the cj amp with a panel speaker and prefer it to any solid state amp anyone could provide.

my point is, in the real world of amplifiers, some tube amps will not sound the same as some solid state amps, for whatever reason.

Gawd, I LOVE Shostakovitch. You can't have too much power in da house to play him back realistically.

I was fortunate enough to see Rostropovich conduct the Seattle Symphony Orchestra in April 2006 to commemorate Shotakovich's 100-yr birthday. I was sitting in the front row, about 4' from Rostropovich himself.

Now THAT was dynamic. I'm so glad I got to see Mischa one more time before he left us.

...the meter can't really keep up with the quick changes - so it [maximum SPL peaks] might be a tiny bit higher.

Count on it, like 110 dB or so. You could easily eat up 150 wpc powering Maggies playing Shostakovich.

Yeah, exactly. I just did the (dynamics, not amp a vs b) test mentioned above, and on the Shostakovitch disk got a couple of 105 db peaks and many, many over 100 db on a nominal level of 78 db. I was using fast / C weighting. Quite dynamic! I probably had it a little high - the level I normally listen to that track with has it opening at 76 db or so. And the meter can't really keep up with the quick changes - so it might be a tiny bit higher.

Tests such as Mr. Clark's are pointless in my experience. If he "proves" his premise, it's just a parlor trick anyway. It often takes me weeks to get my head wrapped around how an amp or preamp sounds, and more importantly, how it makes me FEEL when I'm listening to music with it. A test where two or more amps are dialed in to the same sonic signature, are not tested to their extremes, and switched back and forth for comparison in far less time than I take to evaluate an amp throws out most of the criteria and methodology to determine whether one amp sounds better than another. Like I said, a parlor trick.

The limitations he puts on the test are any of the very ones that makes one amp more pleasurable to live with than another, such as how they perform at the frequency extremes, how linear the response is, and how it sounds when pushed, including how much headroom it has on crescendos.

Furthermore, if you think being able to push the Maggies to 96dB is plenty, guess again. If you want it to sound like real music, you want to be able to produce clean, fast peaks above 100 dB even if the average listening level is around 80 dB. Transients, sforzandos, crescendos, drum beats, and all that. A system that can only produce clean peaks to 96 dB is going to have a very limited range of program material that sounds good. I hope you like acoustic folk trios.

While I was composing Drubin's comment got in there. So 'agreed overall' with both of them - but I was referring to MrTennis originally.

Agreed overall. Maybe an extremely minor impact. But, I like academics! And I do have the belief that if we all have similar logical patterns and similar data people should generally eventually come to the same conclusions - I know I'm a hopeless philosophical optimist in that way, but I enjoy life from this perspective more. I am very aware it rarely happens in real life.

Okay - so I found the perfect amplifier. (Well - this is in the 8-Ohm region, but useful for reasons you will see nonetheless. The Onkyo is still the lowest budget 4-ohm I can find.) It is called the "iSymphony Micro Music System". It is 29.99 and has a whopping 14 watts, and weighs about a fourth of a pound.

At 85 db sensitivity for my 3.6s, If I calculate right, that gets me to around 96 db - not precise calc, but close. Plenty loud!

Then, sitting in Radio Shack holding this thing in my hand, I thought about something. First of all, of course this thing will stink up my living room with its sound at 96 db. Actually - what would be really fun is to see if I could melt it after 4 hrs of 96db playing. Okay - but I was thinking. And this relates to the requirement I am imposing to use Maggies for the test. Again, we have to remember what he is saying very specifically:

9. The amps will not be overloaded during the session from either a voltage or current requirement.

The trick about electrostatics is that they are hard to drive. So if he is going to hook up electronics to the cheap amps to see when they are overloaded and say 'its overloaded, you can't run it this loud' because he is working with the real watt number vs published and it is far less - in this case maybe 4 watts per channel instead of the claimed 14 (14 might be both channels, so that is 7, then lets say they overestimated by 2x), and then with Maggie 20s or 3.6s we end up at some super low db, and I can barely hear the music let alone differentiate it, then that might be the thing!

Megabuck amps don't overload as easily. Even Pass Amps - take the XA100 vs XA100.5 - the 100-not-point-five was an 8-ohm amp and didn't double down into 4 ohms. The 0.5 added that, if I understand correctly by adding output devices to support the increased low-ohm load. So even the 100 vs 100.5, on a 2-ohm or 4-ohm speaker driven really hard should sound different, let alone compared to a 29.99 receiver. The Aleph 3 was tested by Stereophile as stable into 1-ohm and lower loads.

Okay - so this is somewhat interesting. The use of his challenge/research into these issues comes out as statements such as "all amps within their ranges sound the same" and for electrostatics we might find that on the 'possibly correct' side, but *irrelevant*. Because we have to spend a certain amount of money to get an amp where the "within their ranges" produces music loud enough to enjoy.

Shostakovitch's 8th, 3rd movement, for example. I think he is simulating bombs or early WWII rockets coming down during the siege of Stalingrad or some other battle, and for that half second the music might be 95 or 105 db or something, whereas it is 85 before and after. If our requirement is that those parts sound perfect (isn't that why we get expensive stuff - so it is sounds great at the extremes?) So now, the requirement is 105 db stability at 4 ohms. Not easy! That is 85+20 db, so 9*3 is larger than 20, so 1 doubled 9 times is 1->2->4->8->16->23->64->128->256->512. That is a lot of watts! And we are talking real watts, not marketing watts.

I'll try and get a read on the db of the peaks during that piece if I can tonight.

Not sure if I still want to do any tests this weekend, I've resolved in my mind the issue of $50 and $100 dollar amps/receivers compared to Pass equipment.

The issue of a $1k amp vs a $5k amp is another matter that I'm not interesting in starting a discussion on here. That remains open, and his testing methodology might be interesting (in that it adds an EQ and thus suggests that all of what we feel are important differences may in fact be resolved through TACT/Rives type high quality EQ equipment) for that question.

Note that 'tube experts' have failed his test comparing tubes to solid state (let alone Class A to Class B to Class D solid state) because his eq was able to make the SS state amp sound like the tube amp or vice versa, don't know which way he went.

So, in summary, things decided:

1) Personal Claim: His methodology so far seems sound within its own realm - within its stated claims and limitations
2) Fact: Hard to drive speakers require serious amps
3) Fact: Serious amps are generally more expensive
4) Conclusion: It is worth buying expensive amps if you want good sound from hard to drive speakers
5) Conclusion: His 'all amps are the same' testing methodology has nothing to offer us pro *or* con in terms of #2 - 4 above - it doesn't deal with those issues at all

Things still open:

1) Do amps play a part in non-EQ-alterable sound artifacts, like soundstaging for example.
2) If we think they do, then can we ABX our way through identifying them?

Don't discuss those here, however! Lets leave this thread focused on super-cheap amps versus amazing amps used with electrostatics.

Well, that was time well spent, no?

:)

Mr T., what if the veracity of the claim was demonstrated TO YOU beyond doubt, such that the only conclusion you could draw as an intelligent and reasoned person, is that the differences you thought you heard all these years were an illusion? Beyond any shadow of a doubt.

hi lightminer:

what differnce does it make if you do or do not detect differences ?

people will still buy amp a instead of amp b, regardless of the outcome of this test.

at best it is an academic exercise. at worse, it is a pointless exercise.

this test will have no affect upon purchases of components.

Soundlabs are probably better for this as they are rated at 8 ohms, then I could very easily get a $40 amp versus the 4-ohm rated ones which are of higher quality.

Oem - I think your point about Carver actually possibly supports what this guy is saying. Remember, the premise here is that he will use an EQ in front of one amp to make it sound like the other to eliminate soft top or bottom ends. He agrees that some amps are softer or stronger on top or bottom end etc., and says that this is not the main thing people are saying is better or worse about amps - he says other people are saying there are other aspects of amps that are better/worse in sound quality other than what can be adjusted with an EQ.

Anyway its just a few hours (hopefully) to conduct this test this weekend, so here goes. And of course, I'm not going to frequency EQ the 2 amps like he would, but at least I want to make sure I can hear the difference between the stock forms of 2 amps.

So, I've been looking for the 'cheapest' 4-Ohm rated amplifier I can find. This is one candidate:

http://www.onkyousa.com/model.cfm?m=TX-8222&p=i&class=Receiver

I have nothing against Onkyo - I was hoping for a much lower brand, but that is a $150 receiver and is rated at 4 OHMs for use, and should sound different than the high end Pass Labs stuff.

One of the problems I'm having is:

9. The amps will not be overloaded during the session from either a voltage or current requirement.

So, part of the Maggie 'thing' is that many amps would be current overloaded, and that is part of the point of getting an expensive amp. I do have a multimeter and could detect the amps or voltage at the terminals, but don't have the electronics to determine if the current will be overloaded on the cheaper amp.

All of this leads me to believe that the issue may be in the definition of the problem - you have to at least get to the Harmon Kardon/Rotel/NAD level to drive ribbons, electrostatics, or quasi-ribbon speakers without overloading the amp. A more interesting test might be, given a really really solid 1k amp, can 10 people detect the difference between that and a 10k amp - that is a much more subtle thing, but lets start here and see if we can resolve the $150 amp vs best amps in the world first.

And, regardless, I want to get 90% or better on the test (not necessarily 12/12 as is required for the 10k - but I do agree I would get 12/12 if I were comparing apples to oranges, which is what he is saying we say about amps and if I were giving away 10k I might also say 12/12.)

If anyone knows a 'worse' receiver or amp that says 4 Ohms somehwere in its manual let me know.

Years back Bob Carver said that he could tweek his amp to sound like any other amp in the marketplace.
That statement suggests that Mr.Carver thought that amplifiers sounded different from each other.Not that he or anyone else needs my affirmation but I indeed agree that amplifiers have different sound.Isn't this challenge similar to another that M.F.of Stereophile debunked a few months back.The criteria for winning the prize keeps changing as one gets closer to the finish line.Forget about the test and just enjoy the music.
That said,I don't know why I am even taking the time to post on this thread

As much as i hate the idea he could be right, it does beg the question.....why hasnt anyone won yet!

Cool - so do a 'home test' if you have the couple hours. (btw, that is a *very* cool looking amp.) Have someone get 12 tracks (I think that is what he suggests) put a sheet up over your stuff and have someone do the switching. Do the full abx test as he describes. He is picky about getting all 12 right.

I'm going to try it in next few days out of personal interest. One problem, though, is that reading enough info about this - a few people have gotten all 12 right, then he does level adjusting to within 1/10 of a db and then they don't pass the 2nd time. He doesn't like to start with all that level matching just because it takes a while. So keep that in mind - and this isn't in question - mild increases in volume can make piece A sound better than B whether it is CD player or whatever.

If you get it right, maybe you can make 10k. Or maybe its just bunk. I'll know more when I do the tests in a few days, maybe this weekend.

I have a Denon AVR and a Manley Stingray. Every once in awhile, I listen to the Denon. It sucks compared to the Manley. The difference is not subtle.

Well, 2 reasons. I don't know if the offer still stands, but he offers $10,000 to anyone who can pass his test.

If you win you can buy an amp with that money :).

Second reason, to add to the body of knowledge that exists in the public domain. People use references to his information to suggest that amp A vs amp B - there is no difference as long as they fit certain basic criteria. And he does acknowledge certain features, like if it makes a big thud on starting that is less desireable than otherwise.

If he is right, great, lets spread that knowledge. If he is wrong, well, then lets figure that out and put the issue to bed!

Also - here is a long thread (you can waste maybe a whole 2 hours on this! :) ) - lets no rehash what has already been discussed. There are lots of these.

http://www.audiogroupforum.com/csforum//showthread.php?t=2759

So - bottom line - can we differentiate an X350.5 vs a $20 amp from radio shack using Magnepan 20.1s? (or whatever is cheapest 4 ohm amp).

Why would anyone care?