Do Amplifiers Sound Different?

[Russ L]

Ade- I don't think you can reduce the audio experience down to an "objective" we all truly hear with the same listening curve and our biases prevent us from realizing the truth of the situation. There are positve and negative biases that affect our hearing. Negative-more money is always best. Positve-High end is usually the best or the memory we have of hearing Yo Yo Ma play in a certain concert hall influences our perceptions. This plus individual genetics and life experience make the audio-video world an unique individual experience within the broad range of human hearing. To sum up-we should all listen to MACS and B&WS! The best!

[Ade]

Ade- I don't think you can reduce the audio experience down to an "objective" we all truly hear with the same listening curve and our biases prevent us from realizing the truth of the situation. There are positve and negative biases that affect our hearing. Negative-more money is always best. Positve-High end is usually the best or the memory we have of hearing Yo Yo Ma play in a certain concert hall influences our perceptions. This plus individual genetics and life experience make the audio-video world an unique individual experience within the broad range of human hearing. To sum up-we should all listen to MACS and B&WS! The best!

Of course we can't be fully objective when we do sighted listening tests - at least when we're talking about preferences but double blind ABX testing is about as objective as you can get otherwise.

And I'll be the first to admit I bought the 804S because I liked its cool curved cabinet not because its performance was worth the 50% more over the 703. Sure it was a little better in certain respects but not that much. So yes, I can be as subjective in my opinions as anyone else but at least I’m honest about it.

[Ade]

I think there is something much more significant going on. Why would we assume that we are all endowed with equal hearing? Why would we think that someone else will hear exactly what we are hearing? I see no reason to assume that. After all, we are all demonstrably different in all other physical aspects of our bodies. Some have great voices, some are heavy and others slight, some are blessed with great coordination and others are not, some have perfect pitch and others are tone deaf. The list goes on and on. Why would individual differences not be present with our hearing?

Of course there are differences but not to the extent that some people can hear things that aren't even measurable. The range of a persons hearing and its sensitivity is well understood and it's quite easy to test; many millions have had their hearing tested over the years and as far as I'm aware not one has turned out to have the hearing of superman.

Golden ears do not exist. Double blind ABX testing has shown that time and time again.

One more thing. The concept of price/performance ratio has no more meaning here than it does in F1 racing. While diminishing returns come into play, you still get what you pay for. It's a cosmic law.

Sparky

You get what you pay for? Cosmic law? Seriously? Hm, so that 2m speaker cable costing $5000 is worth that then? How about the 1m power cable at $2000? Given the opportunity, some companies would not think twice before screwing people over to make a profit. Now that is a cosmic law of human nature. The depth of some people’s gullibility is another.

[pearsall001]

Gee Whiz, if everything sounded the same where would the fun be in putting a system together? We should all just but a HTIB system from Wal-Mart along with a $50 DVD/CD player & we'd be all set. Boy that was a lot of fun!!! Now back to my critical listening. Cheers!!!

[Alaric]

Of course there are differences but not to the extent that some people can hear things that aren't even measurable. The range of a persons hearing and its sensitivity is well understood and it's quite easy to test; many millions have had their hearing tested over the years and as far as I'm aware not one has turned out to have the hearing of superman.

Golden ears do not exist. Double blind ABX testing has shown that time and time again.


You get what you pay for? Cosmic law? Seriously? Hm, so that 2m speaker cable costing $5000 is worth that then? How about the 1m power cable at $2000? Given the opportunity, some companies would not think twice before screwing people over to make a profit. Now that is a cosmic law of human nature. The depth of some people’s gullibility is another.

The nerve endings in a human fingertip can discern differences in texture measured in microns. Why is it so farfetched an idea that the nerves in the eardrum (and beyond) can be at least as sensitive?

[Kal Rubinson]

The nerve endings in a human fingertip can discern differences in texture measured in microns. Why is it so farfetched an idea that the nerves in the eardrum (and beyond) can be at least as sensitive?

Actually, hair cells in the inner ear will signal even less of a displacement. That, of course, doesn't necessarily translate directly.

Kal

[David Meek]

Okay gang, things have stayed reasonably civil in this thread to this point (which is somewhat surprising considering the topic) so let's keep it that way. Like I've said before: I like informed, even passionate discussions about things, but I won't tolerate any unpleasant behavior. Carry on. . . .

HTG Administrator

[Martyn]

On the subject of perception at the physiological level, I'm certain that some of our senses vary from one individual to another, although I suspect that they vary only in sensitivity; I don't believe that our senses work differently from one person to another. However, differences in sensitivity across the sound spectrum could account for personal preferences of one piece of equipment over another (this is highly speculative on my part).

At a more down to earth level, when I was about 50 I discovered that I have had some hearing loss from birth. This shows as a depression in my ears' frequency response right in the mid range! I had no idea I had this until an audiologist gave me a frequency sweep. This might mean that I will prefer the sound of equipment that emphasises the mid range. What's more, I recently learned that this hearing deficiency is quite common among men. It's rather ironic that some of us are doing our best to be audiophiles without knowing that we are partially deaf!

Finally, at a more simplistic level, we all get used to the sound of our systems. When we hear something different, in the absence of some real objectivity it's easy to confuse "different" with "better". Not forgetting, of course, that sometimes some of us might just need a reason to buy another piece of hardware...

[bowlman]

I am new to this site ,and to high end audio. My question is,,when everyone compares amps no one talks about what models are being compared. I do not want to hear about price,I want to hear about amps in the same catagory or close.
The reason is volume makes a big differance. I have seen salesmen a-b amps and have to adjust the volume up or down,could this make a speaker bright or warm ??

[Race Car Driver]

Well ive just had my first experience comparing amps. I have a Monster 3250 and an Aragon 4004 at my place right now, and there is definatly a difference between the two. I have heard different amps, and different speakers, i have not had the chance to A/B two amps on the same set of speakers at my own descression before.

Just my two cents. Will be adding two Bryston 7B NRBs into the mix next week.

It is nice to be able to compare back to back and switch back to the original if you like.

This is nothing new either, installing mobile audio it was the same thing, different amps sounded different.

[jonathanb3478]

I have had my little Parasound HCA-600 for over a decade now. It has been immune to my upgraditis over the years. The reason is not because I have not heard difference between it and more expensive amps.

I posted my thoughts on this, at the time, here. The short version:

Sometime in '97 I think, I had to take my parents car to the car dealer and the car dealer said it would take all day to finish. I knew this and planed ahead. I just walked a block or two down the street and listened for 7 hours to a single system setup at a nearby audio dealer with material I brought from home. I LOVED it. The system:

Marantz single disc CDP (retailed for around $650 - can't remember the model)
Audio Research LS-8 (2k tube pre)
" VT60 (3k tube amp)
Hales Concept 2 (2.4k two-way floor stander)

About an hour before the car repair shop called me at the audio shop to tell me my parents' car was ready, I made it through all the CDs that I brought with me. At that point I wanted to experiment. I asked salesmen with nothing to do at the moment if he would be willing to replace the Audio Research VT60 with a Parasound HCA-600 they had in another demo room. He said sure, and I started to listen.

The first thing I noticed was a much stronger bass impact. The next thing I noticed was that the "definition", "attack", or "impact" was stronger throughout the whole frequency range. Everything was so much better defined. The amp seemed to demonstrate much greater control over the speakers during sudden dynamic events such as symbols, high-frequency plucked guitar, drumbeats etc. By contrast the Audio Research was almost sloppy. Only by direct comparison, remember. I loved the original system while I listened to it.

The final thing I noticed was what could justify the Audio Research's 3k price tag. More resolution, no doubt about it. The HCA-600 had a "grunge" sounding like an "electronic haze" that obscured detail.

I found myself still coming to, what to me anyway, was an amazing conclusion. I preferred the HCA-600 overall, regardless of price. The reason was simple. The improved "definition", "attack", or "impact" (whatever you want to call it) displayed by the HCA-600 was dramatic as a percentage increase. The amount of detail that the Audio Research VT60 picked up that the HCA-600's "grunge" masked was, as a percentage improvement, comparatively small. A lot smaller. A whole lot smaller. I did not care in the least if I lost that much resolution to pick up so much definition.

[Boombox]

Four points to make:

1. More expensive equipment offer better quality of sound. No discussion. I was auditioning Dynaudios on two different days. (setup - a) Rotel RCD1072 + Meridian Pre-amp + Rotel RB1080 + Dynaudio 72. Fantastic sound. (setup - b) Rotel RCD1072 + Rotel RC1070 + Rotel RB1080 + Dynaudio 52SE. Amanzing + Fantastic sound. However, the Meridian pre-amp comes in at R21 000 ($3k). We all know how much the RC1070 is. I must say that with 'set-up a' the Meridian was gone. There was "no" pre-amp. I did not realize this until I listened to setup b. To my ears the 52SE was sonically superior to the 72s, but the RC1070 did leave its mark (or, rather, laceration) in the audio chain. If I were to continue with "brighter, transparent, depth, blah, blah, blah,...." Hi-fi choice will approach me as to be a reviewer.... :B.

2. Would I pay $3k for the Meridian. No. These "price brackets", "competing with the likes of", "mid-priced", "budget", "hi-end", terms and phrases impact so profoundly on one's subjective reasoning and hearing abilities, that if you tell someone that the one hi-fi was 5k and the other 20k, the person will inevitably find somewhere it his/her brain a reason why the 20k's sound is better...my point is that manufacturers, to some extent, bet on this, and would therefore decide beforehand to market their "high-end" or "budget" product as such.......budget or high-end....is their better physics or electronics in the equipment allowing it to cost more....I don't know but here is an intersting review on one of the sponsor's product of this forum:

http://www.hardwareanalysis.com/content/reviews/article/1828.5/

follow up:

http://www.hardwareanalysis.com/content/article/1831/

3. Now to the science and engineering. I am sorry, but music is AN ART!!!! And should be treated as such. We love our favourite tracks and some equipment just reproduce that track and its emotion so on the spot to our individual specifications, that we find ourselves not wanting to let go of the hi-fi equipment. It does not matter what physics and electronics goes into the product, at the end the consumer's spirit/emotions will cry out and say....yes, yes, yes......do you take check or credit card....?? The only piece of science that goes in here is the fact that the price/performance curve is not linear or exponential, but rather logarithmic, with price on the x-axis and performance on the y-axis....which leads me to my final point....

4. Rotel IS budget to mid hi-fi. Sorry!! ..things get sonically remarkably better $5k more.....I think Rotel knows this better than us consumers, that's why they sell fantastic products at the price. That's why you have to dig very deep for a significant improvement....more than $10k it becomes marginal IMO.

[Karma]

On the subject of perception at the physiological level, I'm certain that some of our senses vary from one individual to another, although I suspect that they vary only in sensitivity; I don't believe that our senses work differently from one person to another. However, differences in sensitivity across the sound spectrum could account for personal preferences of one piece of equipment over another (this is highly speculative on my part).

At a more down to earth level, when I was about 50 I discovered that I have had some hearing loss from birth. This shows as a depression in my ears' frequency response right in the mid range! I had no idea I had this until an audiologist gave me a frequency sweep. This might mean that I will prefer the sound of equipment that emphasises the mid range. What's more, I recently learned that this hearing deficiency is quite common among men. It's rather ironic that some of us are doing our best to be audiophiles without knowing that we are partially deaf!...

HI Martyn,
When I first had my hearing tested in high school the audiologist was amazed at my results. She had never seen results as good. Since then I have made a point of having my hearing tested every couple of years. Having my hearing tested often is easy since I work at a National Laboratory where the tests are offered free of charge at my request. Test results are retained in a database so an individual can, if they wish, have a history of change over time. The results have remained at a very high level. However, there have been changes in my high frequency response due to age. Even so, and even at my age, my hearing is still well above average for a person of any age.

The standard hearing tests are rather crude. They measure only frequency response and limit the tests high frequencies. The tests are only designed to determine "functional" hearing. Applied to high fidelity, the tests are marginal at best but they do identify gross problems.

Furthermore, I take good care of my ears and I always have. If I have to drive more than just a few miles, I wear ear plugs. They make a huge difference by reducing ear fatigue. If I visit a friend or a hi fi shop to do some critical listening, I wear ear plugs on the trip. My cars have not been noisy but I have determined that even small amounts of road noise over time definitely diminish my ability to distinguish subtle audio effects. Depending on the length of the trip my ears recover but it takes time. BTW, I don't wear plugs in the city because having my ears functional is an important safety tool.

For example, my B&W dealer is about an hour and a half highway drive away. For this trip my ears take about 2 hours to fully recover if I fail (I don't fail to do so often) to use ear plugs. Even with plugs I try to not engage in critical listening for 1/2 hour or so.

Our ears take a lot of abuse from our normal everyday environment. If we don't remain aware of the audio environment constantly we will suffer hearing loss. This is especially true for repetitive sounds such as we might find in our workplace. According to audiologists, this is the most common cause of loss. The next most common is very loud impact type noise such as one finds at a shooting range. Shooters very commonly suffer loss.

So, my friends take good care of your ears and remain constantly vigilant. You will be repaid by retaining the great hearing you had as a kid. And you can justify spending a huge sum on audio equipment because you can hear the differences.

Martyn, one more thing. Your speculation about not believing that individual hearing differences account for the wildly differing opinions is noted. I am also speculating about this issue. But if my original speculation is not true then how would you account for the differences? Actually, I think your assumption is the common one but it may not be correct. It is very difficult to know. There are no tests that can measure our ability to dig deeply into a sonic field and hear the subtle effects. I am basing my idea on 40 or so years of serious involvement in high end audio and also many observations of reactions to the hearing experience in controlled circumstances.

I stand by my original statement. There are many variables but in the end it's all about talent.

Sparky

[Ade]

Well ive just had my first experience comparing amps. I have a Monster 3250 and an Aragon 4004 at my place right now, and there is definatly a difference between the two. I have heard different amps, and different speakers, i have not had the chance to A/B two amps on the same set of speakers at my own descression before.

Just my two cents. Will be adding two Bryston 7B NRBs into the mix next week.

It is nice to be able to compare back to back and switch back to the original if you like.

This is nothing new either, installing mobile audio it was the same thing, different amps sounded different.

If I may suggest that for a true comparative analysis you buy a SPL meter and a test tone cd to level match the amps. As has been said many times here and other places - even a difference of 0.1 dB can be perceived as a brighter, clearer, tighter sound with more bass, etc, etc and to the naked ear the SPL levels will sound identical - in fact, the human ear is only just able to discern a 1dB difference in sound levels even in perfect listening conditions.

If you don't level match you aren't truly comparing like with like.

[Kal Rubinson]

On the subject of perception at the physiological level, I'm certain that some of our senses vary from one individual to another, although I suspect that they vary only in sensitivity; I don't believe that our senses work differently from one person to another. However, differences in sensitivity across the sound spectrum could account for personal preferences of one piece of equipment over another (this is highly speculative on my part).

While those variations exist and can be tested, it is probably the central neural operations, where we associate and interpret stimuli, that distinguish us in our tastes in audio.

Kal

[Ade]

I've referenced the old Stereo Review amplifier test on various occasions but unfortunately the original hosting site seems to have died. I've found another site where it's located though so hopefully that will survive until the article can find a permanent AV related home - the amp test can be read at http://webpages.charter.net/fryguy/Amp_Sound.pdf

It's a PDF so you will need acrobat reader installed to read it.

Enjoy.

[LikeCoiledSteel]

Hi Everyone,
I want to thank everyone for their input. It seems this question has escalated into a larger debate about amps. It was not my intent to ask whether more expensive amps sound better than less expensive ones. Logically they should, financially they better.

Nevertheless the discussion is not a new one but interesting all the same. I personally have used about 6 different brands of amps of different calibers and power ratings over the last few years. IMHO, they all sound different. Some subtle, others night and day. Each has a different sound "flavor", with strengths and weaknesses.

I have heard great things about Mcintosh but have never heard them before. I found a Mac for sale online from another enthusiast and like the flexability of it. I do think Rotel makes very good stuff, but may not be my best solution right now. I always like to upgrade proof my purchases. If I decide to upgrade my speakers in the future, I make sure that whatever amp I have will fit the bill. Hence my Krell. I know that if I upgrade to the 800 series, The Krell will do. Same with the Mac. My other amps would not cut it.

Thank you everyone for your help. I will keep you posted if it goes thru.
Steel

[Race Car Driver]

If I may suggest that for a true comparative analysis you buy a SPL meter and a test tone cd to level match the amps.

Id dont listen to SPLs, or listen to test tone cds, i sit down and listen to music.

As has been said many times here and other places - even a difference of 0.1 dB can be perceived as a brighter, clearer, tighter sound with more bass, etc, etc and to the naked ear the SPL levels will sound identical

I never stated that the SPL produced using amp A was the same, lower or higher then amp B, I simply stated that amp A sounds different to amp B, at all volumes. I would have to assume that the higher SPL would result from more power correct? To go up 3 DB you have to double in power. The Monster amp is more powerfull then the Aragon, the Monster sounds brighter, clearer, tighter and has more bass, and I would assume the SPL is higher with this amp. All would make sense, it is a more powerfull amp.

- in fact, the human ear is only just able to discern a 1dB difference in sound levels even in perfect listening conditions.

If you don't level match you aren't truly comparing like with like.

Call it a low-tech approach, I remove amp A, place in amp B, and notice that they sound different with everything else same.

I will stick to listening to music, anyone can feel free to listen to test tones.

[Ade]

I will stick to listening to music, anyone can feel free to listen to test tones.

Uh, yeah. You don't listen to the test tones you just use them to calibrate. Never mind, the concept is obviously lost on you so go ahead and do your "comparisons".

One thing I find utterly bizarre and it’s something I’ve noticed elsewhere too, is that when confronted with that comprehensive Stereo Review amp test all goes quiet for a bit and then audiophiles just go on as normal ignoring the fact that the test even exists. It’s very freaking spooky.

Oh well, whatever.

[Race Car Driver]

I understand the concept of test tones, its nothing new to me. Ive used them in car audio to adjust gain levels on amps to match head units. Im not lost. You didnt pick up on my point.

There was a simple question asked that stemmed from another thread.
Do amplifiers sound different. My answer is yes, amps sound different.

Im not going to go "buy myself a SPL meter and test tone CD" just so my "tests" will fullfill your needs. Hell Id go do that and it still wouldnt be enough, next thing is, well, yea your room isnt treated properly, or your source is not appropriate enough..
The list goes on and on.
I compared (listened) to two amps (not a whole lot of "testing" going on), and the sound from both are different. There was nothing hi tech about it.
Plain and simple.

And to make this clear, im not here to dispute or argue with person A or B.
I dont know what your knowledge is. I know im on the lower rung of the ladder here. I am here to learn and share with others. I just dont see the need to be so technical all the time. Why? I feel it takes some of the "fun" out of it. With that I stand by what I said.

Anyways.
Enjoy

[Russ L]

I wouldn't consider myself an audiophile but I have a passion for good music. I am relatively new to the hobby (4 mo.) I went to my dealer and auditioned 8 different Surround Receivers in the price range between 900 and 2000 CDN. 2 Yamahas, 2 Marantz, an Integra, a Sony, and 2 Rotels. I was left alone in the listening room for an hour(slow time of the week). All the receivers were 75-125w range, all played at the exact same level(in dB) through B&W DM 602s in two channel direct. Same source, same song. I was able to switch between the amps at my whim. To me they all sounded different and generally the more expensive the better they sounded. I ended picking up the Rotel the second most expensive because it was (to me) the clear cut winner. I have a hard time understanding the argument that amplification makes little difference, that individual genetics effect on hearing structure make little difference and that our perception of that sensory input makes little difference. Often experiments suffer because they fail to duplicate the real world listening conditions. Too clinical so faulty results. I think my little test was a fair mix of real world and "clinic". Russ

[Gump]

That "expensive" Classe amp sure sounds great with my B&W 803D's. Makes me happy. Ignorance is bliss!

[Russ L]

We could all use that much Happiness:W Enjoy -Russ

[Ade]

All the receivers were 75-125w range, all played at the exact same level(in dB) through B&W DM 602s in two channel direct.

May I ask how you knew they were being played "at the exact same level"?.

I have a hard time understanding the argument that amplification makes little difference, that individual genetics effect on hearing structure make little difference and that our perception of that sensory input makes little difference.

It seems that some people have a hard time accepting that the design goals of creating a good amp are (and I'll quote an audio engineer/amp designer from QSC), "a straight wire with gain."

In other words they are designed and built to be transparent and unlike speakers it's a relatively easy task. Think of them as a glorified power supply.

Every single blind test that I have ever read shows that people cannot tell the difference between amps costing 10's of thousands and 100's of $. If you haven't read the test I posted yet, have a look - it was run by one of the biggest HiFi magazines of the day, which is now called Sound and Vision (and they wouldn't even dream of upsetting its advertisers by publishing something like that these days).

Amplifiers sound different for 2 reasons;
1) they are playing louder which is not always obvious as the ear can only differentiate 1dB increases as being louder (and that’s under very good conditions) but a 0.1db increase can make sounds seem clearer or brighter - just read Mr Racer's post from yesterday, sound familiar? Some manufacturers play with the volume control, giving more gain in the initial 45 or 90 degrees to give the psychological effect that it's "louder" or “better” and no two amps will be identical in their volume control calibration.

When amps play at the same level within their clipping limits all will sound the same; if they don't, the amp is broken or it's a badly designed one.

2) The psychological effect is something that people have the hardest time accepting. Our hearing is readily prone to distortion due to bias, more so than our other senses - it's one of the reasons why auditory hallucinations are far more common than visual ones.
If you read that review you will find that during the sighted part of the process even the skeptics that didn't believe there should be a difference heard them and were amazed.
No matter how critical we think we are we are still all influenced by subtle psychological programming from marketing and even from our own backgrounds that are unrelated to AV.

Often experiments suffer because they fail to duplicate the real world listening conditions. Too clinical so faulty results. I think my little test was a fair mix of real world and "clinic". Russ

This is usually the argument used by audiophiles that are upset by failing a blind test.

There are challenges out there for many 1000's $ - if you can differentiate between 2 amps of your choosing during a blind test when both amps are within their clipping limits you get to keep the money. No one has yet and never will.

One more thing - there are reasons to buy more expensive amplifiers; more power and better heavy load capability (<4 ohms), clipping limiters/soft clipping, better build quality, better looks, uh, status... etc.
You can get powerful amps from a lot of companies that don't have a "prestige” badge and have a lower price tag as a result – if I had the choice of a pair of B&W804 plus a top of the line Classe amp or a pair of 803D (or even the 802D) and a NAD I know which I’d choose, how about you? In other words, spend your money where it makes the most difference, on the speakers.

You say you are new to this hobby well so am I - I read a lot of technical articles as well as forums like this though and that makes a big difference on determining what is the truth.

[Aussie Geoff]

You say you are new to this hobby well so am I - I read a lot of technical articles as well as forums like this though and that makes a big difference on determining what is the truth.

A thought for you... You have stated basically the same opinion different ways several times in this thread... I think we all know what you think... Equally we have other members who have listened and compared and are happy that they can hear a difference... You stating that they can't hear a difference or are fooling themselves is not going to change their minds... Indeed (from my experience) in will agravate some people...

I too used to (and still do) read lots of technical articles... Then (and it is the best thing I did in HT) I went and did lots of comparative listening and found myself some good stores with the time and paitience for me... Fooling myself maybe - but I learnt a lot about what I do and don't like..

So, can I gently suggest that you go and find a friendly HT store and do some careful comparative listening. Try different amplifiers, cables, speakers, CD players etc... And then when you have done that, you can post again with some authority... Perhaps you won't hear any difference between components (if so, good luck to you). Or perhaps you will... Either way it is so worth doing...

Best of luck

Geoff

[peterS]

the best explanation for why an amp in a given setup sounds different from one swapped in its place is due to the interaction of output impedence of the pre amp and input impedence of the amp
anyways:

http://forum.elitecaraudio.com/showthread.php?threadid=123226&pagenumber=1

[Ade]

A thought for you... You have stated basically the same opinion different ways several times in this thread... I think we all know what you think... Equally we have other members who have listened and compared and are happy that they can hear a difference... You stating that they can't hear a difference or are fooling themselves is not going to change their minds... Indeed (from my experience) in will agravate some people...

I too used to (and still do) read lots of technical articles... Then (and it is the best thing I did in HT) I went and did lots of comparative listening and found myself some good stores with the time and paitience for me... Fooling myself maybe - but I learnt a lot about what I do and don't like..

So, can I gently suggest that you go and find a friendly HT store and do some careful comparative listening. Try different amplifiers, cables, speakers, CD players etc... And then when you have done that, you can post again with some authority... Perhaps you won't hear any difference between components (if so, good luck to you). Or perhaps you will... Either way it is so worth doing...

Best of luck

Geoff

That was an attempt at a friendly, "shut up now", right?

OK, no problem, but one last thing for those "golden ears" out there; why not make some money out of them? The Richard Clark $10,000 Amplifier Challenge FAQ :B

[peterS]

what interests me is the assertion that amps that do not use feedback, while having higher thd, sound better

[peterS]

That was an attempt at a friendly, "shut up now", right?

OK, no problem, but one last thing for those "golden ears" out there; why not make some money out of them? The Richard Clark $10,000 Amplifier Challenge FAQ :B

... rather you read the link i posted

[Boombox]

what interests me is the assertion that amps that do not use feedback, while having higher thd, sound better

explain more (or express your view and opinion) about not using feedback, and Class A amps and if they really DO sound better than the regular Class AB amps...

[Race Car Driver]

... rather you read the link i posted

Pretty much

[peterS]

explain more (or express your view and opinion) about not using feedback, and Class A amps and if they really DO sound better than the regular Class AB amps...

http://www.meta-gizmo.com/Tri/otlology/BERNINGS.htm

stephen mantz of zed audio also has suggested this
while i have simultaniously read adding negativefeedback is neccissary to accieve the ultimate gole in SQ : low thd

i think this makes for a more interesting discussion than a "watt is a watt"

[Russ L]

Hi Ade- I checked out David Clarks amp test in Stereo Review and I'm afraid his methodology is highly flawed. His experiment is not in a respected scientific journal,it would have to be to follow the scientific method. He is not a Cognitive Psychologist and would need to be to conduct such a study. The "study" suffers from selection bias, Experimenter effects, improper collection of data, is not truly blind and has not been replicated by accepted scientific method.(among other problems) It could only be replicated if this study was conducted in a scientific journal and it was only in a stereo mag. This article is as subjective as any other review of amplifiers. -Russ

[soundhound]

Question originally being, do Amplifiers Sound Different? Just in case the original poster has hung around long enough. Theory aside, If your speakers, and sources are up to it, sure they do.

[grit]

Question originally being, do Amplifiers Sound Different? Just in case the original poster has hung around long enough. Theory aside, If your speakers, and sources are up to it, sure they do.

Ain't that the truth. Depends on the rest of the system.

[Boombox]

....I'm afraid his methodology is highly flawed.....This article is as subjective as any other review of amplifiers...-Russ

I can't agree more!!!! I also gave it one glance and came to the exact same conclusion....

[Boombox]

http://www.meta-gizmo.com/Tri/otlology/BERNINGS.htm

stephen mantz of zed audio also has suggested this
while i have simultaniously read adding negativefeedback is neccissary to accieve the ultimate gole in SQ : low thd

i think this makes for a more interesting discussion than a "watt is a watt"

peterS....the link is broken....tried accessing it...

[bigburner]

Solid state amplifiers are by definition linear circuits and are therefore designed to accomplish one task only, and that is to amplify an input signal. They do nothing else.

This presents manufacturers of amplifiers with a challenge - “how do we differentiate our products from our competitors’ products?”

Superior build quality is the strategy adopted by some manufacturers. For others it is superior marketing.

Voicing is the strategy adopted by yet another group of manufacturers. Voicing is distortion and/or frequency-dependant amplitude variations that have been deliberately built into the amplifier.

Voicing has been developed as the result of studies conducted on human hearing. Those studies show that humans prefer to hear a particular set of frequencies with particular amplitudes. For example, high even order distortion sounds warm to many people, while high odd order distortion sounds harsh.

Valve amplifiers are proof of this. Many audiophiles speak highly of valve amps even though on paper their distortion specifications are poor. Those people probably don’t realise that they are listening to a grossly distorted sound caused by a high content of even order distortion, which by a trick of nature sounds pleasing to humans.

So in summary, amps with added voicing do sound different. As for the rest, well...

By the way, I can identify a voiced amp simply by looking at it because I have been blessed with superior eyes.

‘Diamond Eyes’ Nigel

Acknowledgement to Victor.

[jim777]

By the way, I can identify a voiced amp simply by looking at it because I have been blessed with superior eyes.

:roflmao:

I can also recognize a Sony logo when I see one


P.S. I'm kidding, I've only heard Sony's low-mid-fi stuff..

[Victor]

bigburner,

I see that I am being quoted, - thanks for the acknowledgement.

Indeed this is a hot topic with a great emotional content.

I would like to add only one more thought to my original statement in the post #83. That is, - what we are trying to do with our hobbies is to reproduce the sound that is encoded on the source medium. We are not trying to create any new sound. The Power Amplifier therefore must by definition simply hand over the signal it received from the source to the speakers. Conclusions regarding the ‘sound of amplifiers’ are then a simple logical inference, - the amps must have no sound of their own.

regards,
Victor

[dknightd]

I think the OP has everything he needs to determin if amps sound different. Just switch the adcom and krell and see if their is an audible difference. He as asking specifically about using mcintosh amp with b&w speakers, which is a fine setup. McIntosh amps seem to sound a little smoother and warmer than both krell and adcom in my experience. Of course it could be those old style meters that fooled my ears into thinking there was a difference.
It has always puzzled me why well designed amps, with good specs, sometimes seem to sound different from one another. Some amps cannot deliver the current required by a low impedance speaker, I guess these amps are clipping when this occurs, but it does not sound like what I'd usually associate with cliping, so I'm not sure. I do know that when I got b&w 703 speakers that my yamaha integrated amp couldn't drive them nearly as well as the lower rated adcom 535. I've never tried a blind test, perhaps I would not be able to pass it.

[chrispy35]

His experiment is not in a respected scientific journal,it would have to be to follow the scientific method...It could only be replicated if this study was conducted in a scientific journal and it was only in a stereo mag.

Come on now. Publication doesn't necessarily make the data more or less accurate...it just means that more people have reveiwed and agree with the data. Not everything appearing in a peer-reviewed journal is true either...just look at the first author's name and then ask the 2nd author who did most of the work.

Chris P.

[Russ L]

Thanks Big Burner and Victor for stating so well the case others have been trying to make. So it all comes down to distortion and good amplification. That resolves the two positions quite well! Congrats:T Thats whats needed...reasonable hypotheses backed up with credible (not contentious and emotional) studies. I sure have learned alot from this forum in my first 4 mos. in the hobby! Its helped me pick out the right home theater system to meet my needs and ear without any expensive mistakes. Thanks all Russ

[The13thGryphon]

My two cents worth.

Okay, gotta jump in here and make a few of my own points. (Sorry in advance for the length of the post)

1) Several people have stated something along the lines of "when modern solid state amps play at the same level, and within their clipping limits, all will sound the same." I'd just like to state that in my experience this is silly.

Let's examine the matter. No two amps are laid out, wired, or constructed exactly alike. Amps have differing input impedances, differing output impedances, varying degrees of deviation in the audible frequency range, different levels of Total Harmonic Distortion and Intermodulation Distortion, and differing harmonic distortion components (1st order, 2nd order, 3rd order, etc.), different signal to noise ratios, differing degrees of adherence to a linear phase response (or lack thereof), and different levels of mechanical noise.

The circuit topology of amplifiers differ from one another. Some amps use a Class A design, some are Class A\B, some are Class H, some are Class D, some are Class T, etc., etc.

Designers make different trade-offs based upon what they believe to be important, or upon what they think is allowable within the price point they are shooting for. Component parts selected for use in circuits for a particular amp are different from others used in another similar circuit in a different brand. While one designer will use a particular circuit, or even a particular type and brand of diode, or resister, or capacitor, or transformer, another designer will use a difference circuit and different components.

Yet there are folks out there that are trying to tell me that all of these differences will add up to no difference in the sound that comes out of this complex circuit? Are they crazy??? :E

I tell someone that I listened to a Rotel RCD-1072 CD player, and compared it to a Linn Ikemi CD player, and that I heard distinct differences, and that I liked the Ikemi significantly better than the Rotel; and no one tends to argue or disagree. Yet both players spin the same little silver disks, both were designed to provide musical enjoyment, and both were attempts by a designer to provide as truthful and realistic a representation of the original recording as they could. Yet they sound different... and people tend to accept that this is the case. But let the two devices in question be amps, and suddenly someone is telling me I couldn't have heard any difference, and such differences cannot possibly exist. Sheesh! :

2) bigburner hit the nail on the head when he spoke of "voicing" an amp. No all designers even attempt to create a "straight wire with gain". Many design their amps to provide a specific and particular sound that they find pleasing, or that they believe will allow their unit to overcome some small discrepancy or defect, or simply to differentiate their amp from everyone elses. Yet even when so many designers deviate from a "straight wire with gain" and voice their products, we're told that there cannot be any difference in the sound from one amp to another. Please.

3) I know someone will poopoo this due to it not following strictly controlled scientific methodology... but read it and judge for yourself. I don't know how a test could be more "double blind".

I visited a Magnolia Hi-Fi and was primarily looking for a set of speakers. I listened to several models in the store and was drawn to a pair of Vienna Acoustics Beethoven’s. The system connected to the Beethoven’s consisted of a Krell KPS CD player, a Krell Home Theater Standard pre-pro, and a Krell FPB 200 amp, all connected up with Audioquest IC’s and speaker cables. Sitting on the other side of the low equipment rack was a B&K amp and preamp, with a Toshiba CD player for a source. These components were connected to a second pair of speakers, the Vienna Acoustics Mozart’s.

As the salesman knew me from previous visits he closed the doors to the listening room and carefully verified the setup: exact location of speakers and proper toe-in (matching the markings on the floor), no surround modes or EQ enabled on the pre-pro, set to simple stereo and “pure-direct” mode, and no crossover or sub used.

After listening to several cuts off of the CD’s I happened to have with me that day, I was very impressed with the combination. Tight, extended, tuneful bass, clear and musical mids, and detailed highs without going overboard into sizzle that will cause listener fatigue. I remember listening to cuts from the Holly Cole Trio album “Blame it on my Youth”, and several songs from Eric Clapton’s Unplugged album, and a couple of cuts off of Robert Cray’s “I was Warned” album. I was really pleased with the sound and thinking that maybe I’d found a pair of speakers that I could live with. I went home to get some additional CD’s and headed back to listen further.

When I got back less than two hours later my usual sales consultant was gone for lunch, and another sales person took me back into the listening room. Everything appeared to be exactly as I had seen it earlier in the day. He cued up my first CD – “Steady On” by Shawn Colvin – and I sat back to listen. After a minute or two I asked to have him play a different cut. Although the sales person had been smiling and tapping his foot, something just didn’t seem right to me. The second cut was also disappointing. As I was listening to a different CD than I had earlier, I figured maybe the mix was a little muddied and I’d just never really noticed before... although up until then I’d loved this album and thought the production was top notch. We put on a different CD – “Be Yourself Tonight” by the Eurythmics. Again, after several minutes I just wasn’t feeling it like I had earlier.

At that point I asked him to throw on Eric Clapton’s Unplugged, which I had listened to earlier and loved. That too proved ultimately to be a letdown. The bass was not as extended, and what was there was bloated and slow… not the tight, tuneful, sound I recalled. In addition, the upper mids and highs seemed to have lost a bit of detail and glow. I asked the salesperson to check to see if a surround mode had been turned on, or if any EQ settings had been added or adjusted. After a quick check all was as it should have been, and was earlier. I even walked over to the Beethoven speakers to ensure they were on and playing, and that someone hadn’t switched the speaker leads over to the smaller Mozart’s.

At that point I was at a total loss. I had walked in expecting to be further dazzled by the system that had thrilled me just two hours previous. I was looking at the same big ‘bad boy’ Krell amp, and the same Home Theater Standard pre-pro, and the same Krell KPS CD player, and the same Vienna Acoustics Beethoven speakers… all of which I was admittedly taken with. What was wrong? Suddenly the system I'd been very impressed with earlier in the day just wasn't doing it for me! I'm not saying that it was terrible. It wasn't. It was okay... just not the same caliber I recalled from earlier in the day.

The room was the same, the speakers were the same and in the same place, the source and preamp were the same, the IC's and cables were the same... and I thought that the amp was the same. I had no doubt in my mind that I was listening to the same equipment, but something was indeed wrong with how it sounded. Not terribly wrong as in “yuck”! Just a little bit different. A little less musical; a little “fatter” and slower. A little less transparent. Not tons… but enough to notice.

As I was sitting there trying to understand what was happening, and why I was having such a different reaction to what I believed to be the exact same system, the sales person was checking the connections to all of the equipment. Suddenly he said “Hmmm, that’s strange.” When I asked what he meant he indicated that someone had run the output of the Krell HTS pre-pro into the B&K amp, and connected the Beethoven speakers to the B&K as well. Everything in the system was the same as before… except the amp!

Now why did I hear a difference? I came back expecting to hear the exact same thing I'd heard previously. It wasn't a preconceived belief, as I was unaware that anything had been changed, and I came in expecting to be enthralled again. And you can’t say I was swayed by the look or sex appeal or name of one amp or the other; ‘cause it was the same two amps sitting there on the rack in front of me and I believed I was again listening to that cool, sexy Krell. You can’t say I that my emotions were the cause of hearing something different, ‘cause, again, I believed that I was listening to the same unit. And you can’t say that the sales person somehow consciously or sub-consciously influenced me, ‘cause he didn’t know there had been a change either.

So how do I explain this other than to believe that I could/can indeed discern an audible difference? Form your own conclusion... I know I've formed mine.

[Ade]

I'm sorry Geoff, I know you basically told me that I’d contributed enough but it's getting ridiculous! At least I try to present some sort of supporting evidence not just, "uh, I think it sounds different because I say it does."

....I'm afraid his methodology is highly flawed.....This article is as subjective as any other review of amplifiers...-Russ

I can't agree more!!!! I also gave it one glance and came to the exact same conclusion....

How can you possibly say that the test was subjective? Can someone please explain that to me?

Also, maybe you can explain why this one would be too; the following was a test performed by some guys on the USENET rec.audio.opinion group back in '98. I'll summarize for those of you that can’t be bothered to read the entire thread; an audiophile in the biz (I think he's some sort of installer) challenged two skeptics to test him - they did, with his music, on his system, in his house, with his $12,000 Pass Aleph monoblocks against an old Yamaha integrated amp costing circa $300 to $700 (the price was unclear but it was definitely under £1000). The outcome: neither he, his wife nor an audiophile friend could tell the difference when they were level matched. And of course there were the usual excuses afterwards.

The thread can be seen : here

Then there's a more recent test between a pro amp and a "high end" amp performed be Steve Callas that can be seen here.

... rather you read the link i posted

One thing about Clark's challenge that people consistently fail to take into account; it's his money. If I were in the same position I would be overly cautious about ensuring that not only were the amps level matched but that the distortion limits were equal too - as you can see from the above link and the following, it's really not necessary to do that. As for you other link; yeah, that made me smile.

Hearing Distortion. As you can see, even given the optimum circumstances, our ability to hear distortion is pretty crap.

Voicing is the strategy adopted by yet another group of manufacturers. Voicing is distortion and/or frequency-dependant amplitude variations that have been deliberately built into the amplifier.

I can imagine that some manufacturers have considered this, and I can even believe that they may have attempted it too but if they did that they deliberately corrupted the sound and that would be really bad for sales.

Here's a quote from Bob Lee an engineer with QSC (they build amps), "If there are audible differences between two gain-matched amps, then at least one of them is tinkering with the signal."

And here's another of his, "I'm secure enough in my "business interests" to tell people honestly that sound quality among competently designed power amps is very high … high enough to be mostly indistinguishable from one another. "

I think he was hedging his bets with the "mostly" to take into account those that uh, "voice" their amps although the “competently designed” wouldn’t apply then.

And to top this post off nicely, here is a very readable article by Ian Masters about the debate on amp sound; The Ongoing Debate about Amplifier "Sound"

Enjoy.