[andyr]

... Siegfried Linkwitz claims all modern amps with distortion below 0.1% sound about the same, all other things being equal.

Blind listening tests have tended to confirm it.

Note the caveats - 'all other things being equal' and 'tended'. I know from experience with my LS 88's and other speakers low distortion amplifiers sometimes sound the same - but not always.  Some of the time it is corrected by ensuring they are spl matched (what some dealers will do to sell product is sickening really) but again not always.

Thanks
Bill

Hi Bill,

After dinner and a bottle of red, I'm afraid I have to give vent to my disagreement with many of the things you've said in your post ... and you've covered a lot!  It's a long post!  

Firstly, "Siegfried Linkwitz claims all modern amps with distortion below 0.1% sound about the same, all other things being equal."

Well he might ... however, is what he says bedrock truth?  Rod Elliott (another guru whose electronic designs I use and applaud) says that there is no difference in cables!    But plenty of others say there is!  And there was a notorious British hi-fi-mag reviewer who claimed the same thing (he only seemed to measure amps, he didn't sit down and LISTEN to them)!

All I know is, when I took my old Naim 250 over to Hugh's place about 3 years ago and compared it to an AKSA 55 (NOT, notice, an AKSA 55N+!) the AKSA blew it away!  So I immediately ordered 3 AKSAs and, when I'd built them, sold my Naim gear.

This was not a "blind" test but the difference was so apparent, it didn't need to be.  And, the other day when listening to a couple of different phono stages at a friend's place (another AKSA owner ... I mention this because I don't know whether you are part of the "family" or not!), it was immediately apparent that the "emotional interest generated" by phono stage A was much better than phono stage B!  And this friend's wife, when later hearing A and then B, demanded that B be removed out of circuit forthwith!     (Marty, being a dutiful husband, duly obeyed!    )

I think there is a problem with "blind" audio tests which might - I repeat MIGHT - not occur with blind wine tests in that what is immediately favourable towards one of the contestants might not deliver the same result over an extended period of time?  But also with wine ... haven't you been to a winery and said "wow, that's great", bought a dozen and then regretted it as you've opened the bottles at home over successive weeks?

I believe it is sometimes immediately obvious that one audio component compared to another, "grabs you" ... and this is the "better" component (though it may not "measure" better)!  Other times, it is much more difficult to tell which component you like better, so blind tests might be a useful feature.

Regards,

Andy

[bhobba]

Hi Andy

After dinner and a bottle of red, I'm afraid I have to give vent to my disagreement with many of the things you've said in your post ... and you've covered a lot! It's a long post!

That's what chat forums are for.  And life would be quite dull if everyone had the same views.  

Firstly, "Siegfried Linkwitz claims all modern amps with distortion below 0.1% sound about the same, all other things being equal."
Well he might ... however, is what he says bedrock truth?

Of course not.  But I think it is a reasonable starting point if someone of his knowledge and experience says it.  Now I am not saying I necessarily agree with him - all I am saying is I would be wary of audible differences in amps with distortion greater than that.  

Rod Elliott (another guru whose elctronic designs I applaud) says that there is no difference in cables!  But plenty of others say there is! And there was a notorious hi-fi-mag reviewer who claimed the same thing (he only seemed to measure amps, he didn't sit doen and LISTEN to them!

I have never heard a difference.  But of course that does not mean it does not exist - all I say is verify it in blind listening tests.  And since you are the one forking out the money the tests need not be statistically definitive like you would find in say a drug trial - it only needs to be noticeable by you.  All I ask is you do the test blind and with matched SPL.

All I know is, when I took my old Naim 250 over to Hugh's place about 3 years ago and compared it to an AKSA 55 (NOT, notice, an AKSA 55N+!) the AKSA blew it away! So I immediately ordered 3 AKSAs and, when I'd built them, sold my Naim gear.

I have heard differences in amps as well.  But I have also had amps demoed that salesmen say are night and day - but with trusty spl meter in hand and having a friend help me demo them blind - guess what - I can not tell the difference.  The only amps I have been able to tell the difference are feeding my hard to drive LS88's.  Of course that does not mean they do not exist - it simply means I am not able to hear them.  I have great respect for Hugh and have no doubt he can hear differences.  Heck - if I was at the same listening session I probably could as well.  But as yet I have not found night and day differences - that is for sure.    

This was not a "blind" test but the difference was so apparent, it didn't need to be.

Now here is where I must disagree.  Any fair test must be blind and with SPL levels matched.

I think there is a problem with "blind" audio tests which might - I repeat MIGHT - not occur with blind wine tests in that what is immediately favourable towards one of the contestants might not deliver the same result over an extended period of time? But also with wine ... haven't you been to a winery and said "wow, that's great", bought a dozen and then regretted it as you've opened the bottles at home over successive weeks?

I agree - and I noted such in a previous post.  This is the point John Atkinson made in the link I gave about it.  But if differences become apparent over time then again they would be detectable on a blind test.  In fact John Atkinson claimed he could reliably pick the difference between amplifiers that blind tests showed had a small but statistically significant difference.  All I ask is to have such statements confirmed by a blind test.  And I would be very suspicious of any pussy footing around and fancy excuses for not doing it.

Thanks
Bill

[rabbitz]

I don't get it on this blind test stuff and please excuse my rants and raves.

You walk into a room and you smell a freshly baked cake and then a fart and you can pick the difference (one hopes). You look at 2 photos, 1 in focus and 1 out of focus and you can pick the difference. You pick up the soldering iron at the wrong end and you quickly notice the difference. You get fed the dog's food and you can pick the difference (you probably find the dog is eating better than you). For some strange reason people do not trust the differences they hear with one of the most sensitive instruments around.... your ears. As I said.... I don't get it.

I can see benefits with blind tests for reviewing purposes for commercial reasons but they don't make a lot of sense to me for the DIY builder.... it either sounds great or like crap. I am naturally curious and like to have an explanation for any changes in sound, but I don't dwell on it and appreciate it for what it is, better sound.

When you went to buy your AKSA, what was the driving force to make the purchase? The specs ain't that flash, there's a lot of work and for most, have never heard one and certainly no blind test. So why did we buy and take the leap of faith? For me it was the prospect of superb sound.

I can remember the specification race from the Japanese manufacturers in the 70s - 80s and all they did mostly was to produce products that were not really pleasant to listen to.... great on paper but not so on the ears. The products they were replacing sounded better. If you look around these days, you will find very few amps with the absurd distortion figures they had.

I can remember the Sony CD players with the digital filter switch to alter the sound and it took off like a lead balloon. It just confused users (not another god damn choice) and was more trouble than what it was worth. Besides, the default setting was the best anyway.

I can respect what the artist does in the studio and records to suit their own tastes but, I wasn't there and have no idea what it is supposed to sound like and after all the processing afterwards, I bet it's not a true representation. I'm only interested on how it plays back on my components and has to fit in with my tastes, get my foot tapping and meet my expectations, and if that means a bit of extra harmonics, then so be it.

Q. If you have blind tests for audio, what's the test called for video testing... a blind test?

[JohnR]

And I would be very suspicious of any pussy footing around and fancy excuses for not doing it.

So what. No-one is obliged to "prove" anything to you.

[audiojerry]

Another observation regarding blind tests...

The duration of the test is a serious factor. Blind tests are done within a smal window of time and require immediate comparison between item a and item b. With audio equipment, it is almost impossible to create an environment where all conditions are equal for each item in the blind test.  In addition, even if the blind test results in a clear winner, over an extended period of time that same item may not be looked upon as favorably.

Take speakers as an example because they are generally fairly easy to hear differences. In a blind test, speaker A may be the clear winner because it has a more detailed treble. That same speaker over time may sound fatuiging and downright annoying after listening to it for a couple of hours. A blind test scenario probably would not expose this issue.

On the other hand, let's say that two cd players are compared, and a blind test cannot yield a clear winner, but over time the auditioner(s) comes to realize that cd player A just does not enhance his enjoyment or connection to his music, so he substitutes player B, and this player just seems to grow on him, and he finds greater pleasure in his listening experience.

These are examples of qualities that can exist between component A and component B, which may not be revealed in a blind test. Can we agree that the blind test may not always be valid in judging differences? I believe this is especially true in audio. They are probably less reliable than measurements.

[andyr]

Nicely said, audiojerry.

It's the "extended listning test" which is the key factor and sometimes the "instant" blind test gets it wrong!

And as far as rabbitz's Qu" "If you have blind tests for audio, what's the test called for video testing" ... this should rightly be called a "deaf test"!     Though mebbe this is really what a "double-blind test" is about!!??  

Regards,

Andy

[jules]

quote bhobba:

"the hallmark of the scientific method is to keep an open mind and base your views on observation."

That's a pretty loose view of scientific method. Without getting too lengthy, the idea of scientific method is:-

 * to establish an aim. This aint as simple as it seems. In my view the aim would be something like....

Aim: to establish which amp best conveys the emotional/creative feelings of the music it is reproducing"

next you have to have a method ... aaagh! The method has to be designd such that conditions are standardised exactly and whatever results you get have to be repeatable. So ...

* method: Same room, same lighting, same temperature, same cat, dog, people all in the same mood and you repeat the experiment 20 times or so.

I could go on further about this, as strictly scientific test design is very rigorous and many apparently well designed tests are brought down by some failing of methodolgy that has escaped the expert who designed it. Psychology [where are you Tinker?] is constantly fraught with methodological problems and it's flawed science to try to reduce this to simple measurements that ignore the human ear and the human mind [unless you re-jig the aim stated above].

The design of audio equipment involves large gobs of science but the listening process involves none. The problem with references to A/B tests and other pseudo-scientific method is that it gives a weight to arguments that they do not deserve.

Jules

[bhobba]

Hi All

Very interesting replies.

But let us understand what I am proposing - and it is very simple.  We give greater weight to findings of blind tests - that is all.  I recently read a review of a mod to the benchmark DAC that made use of the controversial bybee filters.  
http://www.6moons.com/audioreviews/benchmark/dac1_3.html

'The difference wasn't subtle. The Reflection Audio unit sounded considerably bigger and fuller, its soundstage deeper while simultaneously projecting a lot more forcefully into the room. Part and parcel of the 'bigger & fuller' picture were clearly enhanced dynamics, dead-obvious on a piece as dynamically intense as the famous opening dirge of this symphony. The stock unit seemed restrained and shut in by comparison. The Quantum Purifiers thus acted as By-beef-ication. It strategically addressed the weaknesses of the stock unit - a sense of mechanicalness and spatial compaction. The modification worked like an expander both in the spatial and dynamic domains.'

No - the reviewer does not have to prove anything to me.  But if I am going to fork out big bucks on a mod or even go to the expense of organizing a listening test to see if the claims are true I would feel much more comfortable about it if the review had concluded with a blind listening test where the reviewer was able to consistently pick the differences they describe.  I know it is the case of buyer beware as in the debacle with amouralling CD's I posted a link about - but there is such a thing as accountability in journalism.  I do not advocate forcing anyone to do a blind test - I simply ask people to try it for themselves as I have done - the results may surprise you.  And the more people that use it the more likely I believe reviews will use it and we will all be better off - at least it will avoid debacles like armouralling CD's. It is a sad indictment on Hi Fi when debunkers like Randini need to weigh in on issues and under their gaze people like John Atkinson resort to: 'Just because the Amazing Randi tells you? Try thinking for yourself, asshole, and stop wasting my time with petulant emails.'.  All such is easily resovled - simply confirm controversial claims with a blind listening test.  

I suggest those that feel uncomfortable about blind tests examine why.  I have found them very useful.

Since this is an AKSA forum I want to state for the record I trust everything Hugh says and believe blind tests will confirm what he and others say about the AKSA - at least using experienced listeners.  

Thanks
Bill

[Geoff-AU]

I can see benefits with blind tests for reviewing purposes for commercial reasons but they don't make a lot of sense to me for the DIY builder.... it either sounds great or like crap. I am naturally curious and like to have an explanation for any changes in sound, but I don't dwell on it and appreciate it for what it is, better sound.

Yep..  I actually ran into this in Rod Elliott's P88 pre-amp.  I was getting oscillation in my OPA2134s at low gain levels (which will happen, it's in his notes if you use a fast op-amp and don't close certain switches..), and although I could simply choose the higher gain level I chose to add 22pF feedback capacitors to all op-amp stages to cut the gain in the high kHz/low MHz region.  Perfect, stable at all settings.  But for one reason or another I didn't listen to the amp much for the following week or so.  The other night I was listening to some stuff I was relatively familiar with and the vocals sounded dark and shut-in.  Thought this isn't right so I put The Wall on (very familiar with it) and it didn't sound right either.

That got me thinking, what the hell happened to my setup?  The only thing I could come up with were the feedback caps, and after removing them things sounded much better.

Now, 22pF caps should be so far outside the audio frequency range that the pre shouldn't be affected by them.  Also, Rod believes that with 22pF the non-linearities of ceramics won't have a noticeable impact.  So, the question then becomes am I smoking crack and imagining the difference? Further listening tests will have to follow both with and without the caps, as I've been too busy (ie not home!) to listen further.  But blind tests aren't possible in a DIY situation.

Though mebbe this is really what a "double-blind test" is about!!??  

Double blind is when neither the tester nor the testee knows what each item being tested is.

[AKSA]

Geoff,

Lag compensation - that is, the cap across the voltage amp which pulls back gain below unity by the HF pole of the amp - is pivotal in the sound of an amplifier.  It actually affects all audio frequencies, not just treble.

You have made a very important discovery - Lag comp, and its baby brother, phase lead - are da man, dude!  Two amps with different lag comp sound quite different.

Oh, and I don't agree with Siegfried that all amps sound the same.  This is just not true, and I'm actually surprised he said it.

Cheers,

Hugh

[bhobba]

Double blind is when neither the tester nor the testee knows what each item being tested is.

Exactly - and not what I am proposing except for maybe controversial claims.  What I would like to see is more reviews like what Modwright did for power chords
http://www.audience-av.com/cable_asylum.htm

To me simple things like carrying out a blind test on friends (at l least I hope he got his friends impressions blind) to confirm your findings goes a long way IMHO.  It would be a little better if he subjected his impressions to a blind listen as well - but hey - none including me is perfect.

And yes indeed for DIY blind testing is not necessary - you are spending your money and doing your thing to satisfy your interest.  How you go about doing that is your business. The value of blind testing is in validating subjective impressions which can be fooled by many things.  I would still use it even in DIY but that is just me because I am very aware of bias.    

Thanks
Bill

[bhobba]

Hugh thanks for your informative comments.

Oh, and I don't agree with Siegfried that all amps sound the same.  This is just not true, and I'm actually surprised he said it.

Since I am the one that posted Siegfrieds views I think it is important to know exactly what he does say:
http://www.linkwitzlab.com/orion-faq.htm#Q3
'Much has been written about the sound of amplifiers in the Hi-Fi Press. Amplifiers can sound different due to non-linear distortion which generates new spectral components. The typical total harmonic distortion specification is merely a guide post and not a complete measure of amplifier distortion. THD should be below 0.1%, as a starting point, for amplifiers not to sound different from each other. More important is the distortion at low output power levels, below 2 W, where an amplifier spends most of its time during music reproduction, unless it is for Hard Rock. The crossover distortion of Class A/B amplifiers is impulsive in nature. It is very broadband and easily overlooked in the noise floor of the amplifier output spectrum. It registers low in a THD measurement, but the spectral components add in the time domain. They are responsible for much of the "solid-state sound". Class A amplifiers do not suffer from this inherent problem, but a well designed Class A/B can match their performance in practice. Amplifiers can also sound different when their relatively high output impedance, or low damping factor, interacts with the combined loudspeaker and speaker cable load impedance to cause a frequency dependent drive signal at the speaker terminals.'

My view is I would be wary of audible differences I heard in amplifiers with distortion greater than 0.1% - I may prefer the amp but would be concerned the preference would fade over time.  I have heard differences in amplifiers with low distortion (even with matched SPL) - but I would not describe it as night and day.  But then again I would hardly describe my experience as extensive.

Thanks
Bill

[AKSA]

Thanks Bill,

I feel much better knowing Siegfried qualified his comments so carefully;  I'm pretty close to full agreement, in fact, though I think there are still audible differences below 0.1%.  Incidentally, at 40W into 4R, the 100W AKSA is 0.045% at 20KHz, so I heaved a sigh of relief on that one.......    At all other levels and frequencies, distortion is typically 0.02% or lower.

His comments on crossover distortion are, as expected, full of insight.  The output device switching events must be very carefully controlled to avoid creating a spray of harsh artefacts at the speaker;  this is very difficult across the 'dead zone' of an AB SS amp.  The AKSA uses a Self Type II double emitter follower, with very carefully calibrated charge suckout between the output device bases.  This circuit is very important, and brings crossover to vanishingly small levels - which is just as well, since global feedback is too slow and almost powerless to eradicate it.

The slowest part of a power amp is the voltage amplifier, by design.  It MUST have just less than unity gain - 0.9 is sufficient - by the pole frequency, which is typically about half a megacycle on a fast audio amplifier.  But don't be fooled by transistor parameters;  the Ft of a transistor is given in common base mode, the fastest of the two voltage amplifying configurations.  In common emitter, that is, voltage AND current amplifying mode, with emitter the common electrode, the speed of the device is very much limited by the Miller capacitance, about which Ginger knows a great deal (and not just because his surname is Miller!!   )  Miller capacitance is particularly malevolent with voltage amplifiers, because it is created across the reverse biased collector/base junction, in an electrical zone called the depletion layer, where the dielectric is critically imperfect.  The depletion layer holds a great deal of charge, all of it constantly shifting around with current flow through the device.  The dynamic capacitance is typically the collector/base static capacitance - 5pF or so - multiplied by the beta of the device.  If the beta is 150, this capacitance is typically 750pF - and since it's charged across the base/collector electrodes, it must be sourced and sunk across both.  When you add the requirement for a lag comp cap from base to collector to confer stabilty, this situation compounds alarmingly, adding effectively (on the AKSA) around 5000pF MORE to charge and discharge, so you can see the diff pair has to drive this and it's tricky. The base in particular has problems doing this, since it's driven from a relatively high impedance.    In fact, the mechanisms surrounding the VAS on a PP amplifier have profound effect on the sound of the amplifier, and the best solution is like most things in engineering - the artistic management of compromise.  I should add that this closely parallels the situation with tube amps, where the driver of the output tubes is critically important also in the sonic signature of the amplifier.

Cheers,

Hugh

[andyr]

... "Much has been written about the sound of amplifiers in the Hi-Fi Press. Amplifiers can sound different due to non-linear distortion which generates new spectral components. The typical total harmonic distortion specification is merely a guide post and not a complete measure of amplifier distortion. THD should be below 0.1%, as a starting point, for amplifiers not to sound different from each other. More important is the distortion at low output power levels, below 2 W, where an amplifier spends most of its time during music reproduction, unless it is for Hard Rock. The crossover distortion of Class A/B amplifiers is impulsive in nature. It is very broadband and easily overlooked in the noise floor of the amplifier output spectrum. It registers low in a THD measurement, but the spectral components add in the time domain. They are responsible for much of the "solid-state sound". Class A amplifiers do not suffer from this inherent problem, but a well designed Class A/B can match their performance in practice. Amplifiers can also sound different when their relatively high output impedance, or low damping factor, interacts with the combined loudspeaker and speaker cable load impedance to cause a frequency dependent drive signal at the speaker terminals." ...

Bill,

As you are quoting the words of Siegfried Linkwitz as "Gospel", perhaps you can set me right because I see:

a)  an anomaly in what SL wrote (I'm assuming here that you took the above quote verbatim and didn't make any mistakes or modify it in any way ... but I'm certainly not going to use my time to check this by going back to SL's site!), and

b)  a difference between what he actually wrote and what you said he wrote (in your earlier post).

Firstly, he says: "THD should be below 0.1%, as a starting point, for amplifiers not to sound different from each other."

This says to me that unless THD is less than 0.1%, amplifiers will sound different - absolutely fair enough!  

However, to me, he is NOT saying that if THD is much lower than 0.1%, all amps will sound the same.  

And what he says about the importance of distortion at low output power levels, below 2 W, again is absolutely reasonable (ie. THD measurements should be taken at 1w or 2w, not full output power!).

Secondly, he says at the end of your quote: "Amplifiers can also sound different when their relatively high output impedance, or low damping factor ... etc..

IE. he is quite clearly saying, here is an artefact of a particular design of an amplifier which will cause it to sound different to another amplifier ... even though they may both have 0.001% THD at 2 watts!  

I believe you are therefore entirely mistaken in your belief that SL said "all amps with THD of less than 0.1% will sound the same".

Furthermore, SL makes absolutely NO mention of clipping ... whereas I believe clipping makes it possible for two identical amps which are identical in every respect (and measurement) xept that one is a 50w (into 8 ohms) amp and the other is a 200w, to sound different - even when they are not being driven hard.  From Pjay's experiment over on AA, even at a "2w average" sound level, the 50w amp will probably be driven into clipping for milliseconds, whereas the 200w will not.  This will produce a sonic difference between them.

I'm also interested in your comment from your prior post; "The value of blind testing is in validating subjective impressions which can be fooled by many things. I would still use it even in DIY but that is just me because I am very aware of bias."

I am also very aware of bias (and "cognitive dissonance", whereby the mod you've just spent time and money on MUST make it better!    ) but how, exactly, are you going to use a blind test in a typical DIY situation where you are contemplating changing from a stock-supplied capacitor to a Black Gate?

The only way I can see that you can "blind test" is by building two amps - one which has the original cap and the other which has the BG.  But ... doubling up like that (with its inherent cost) is not something that DIYers would typically contemplate?

Regards,

Andy

[bhobba]

Hi Andy

As you are quoting the words of Siegfried Linkwitz as "Gospel"

I am sorry for any confusion - I am not quoting him as "Gospel".  I am quoting him as a reasonable starting point in the discussion the sound of amplifiers.

Firstly, he says: "THD should be below 0.1%, as a starting point, for amplifiers not to sound different from each other. This says to me that unless THD is less than 0.1%, amplifiers will sound different - absolutely fair enough! However, to me, he is NOT saying that if THD is much lower than 0.1%, all amps will sound the same.

No he is not saying that - and please note what I said in my posting - 'Sigfried Linkwitz claims all modern amps with distortion below 0.1% sound about the same, all other things being equal.'  I later expanded 'on all other things being equal' and mentioned caveats.  However I agree my words may have conveyed things not intended which is why when Hugh did his post I was quick to give an exact quote to ensure no misunderstanding.

Secondly, he says at the end of your quote: "Amplifiers can also sound different when their relatively high output impedance, or low damping factor ... etc..IE. he is quite clearly saying, here is an artefact of a particular design of an amplifier which will cause it to sound different to another amplifier ... even though they may both have 0.001% THD at 2 watts! I believe you are therefore entirely mistaken in your belief that SL said "all amps with THD of less than 0.1% will sound the same".

Andy please read what I said again.  I certainly agree, as I admitted above, what I did say may not have been a reflection of Sigfreids view - but what you say above is not what I said either.  I even gave an example with my LS88's of when amps with low distortion sound different into difficult loads.

Furthermore, SL makes absolutely NO mention of clipping ... whereas I believe clipping makes it possible for two identical amps which are identical in every respect (and measurement) xept that one is a 50w (into 8 ohms) amp and the other is a 200w, to sound different - even when they are not being driven hard. From Pjay's experiment over on AA, even at a "2w average" sound level, the 50w amp will probably be driven into clipping for milliseconds, whereas the 200w will not. This will produce a sonic difference between them.

I certainly agree with that - in fact I believe one reason some prefer valves is because they have soft clipping characteristics.

I'm also interested in your comment from your prior post; "The value of blind testing is in validating subjective impressions which can be fooled by many things. I would still use it even in DIY but that is just me because I am very aware of bias."I am also very aware of bias (and "cognitive dissonance", whereby the mod you've just spent time and money on MUST make it better!  ) but how, exactly, are you going to use a blind test in a typical DIY situation where you are contemplating changing from a stock-supplied capacitor to a Black Gate?

I certainly agree in some cases blind listening tests are difficult, even impossible, and you described one perfectly.  Which is another reason reviewers should use them - leaving it up to each individual to arrange such is counter productive.  Of course even that will not solve the situation you mentioned.  

Thanks
Bill

[rabbitz]

Take speakers as an example because they are generally fairly easy to hear differences. In a blind test, speaker A may be the clear winner because it has a more detailed treble. That same speaker over time may sound fatuiging and downright annoying after listening to it for a couple of hours. A blind test scenario probably would not expose this issue.

You are spot on. When I design loudspeakers, rarely are the values I come up with during testing, the same as the final ones after I have lived with it for a while. You usually get excited with what you think is the best sound at testing, but clocking those listening hours tells you otherwise.

[bhobba]

You are spot on. When I design loudspeakers, rarely are the values I come up with during testing, the same as the final ones after I have lived with it for a while. You usually get excited with what you think is the best sound at testing, but clocking those listening hours tells you otherwise.

Sure.  But why could not a blind listening test be done to determine which is the best to listen to over time?  But such extremes are not what I am proposing - which is much simpler.  What I am proposing is that all these subjective claims one sees describing Hi Fi gear be put to a simple blind test to determine if those making the claim can hear the differences they describe listening blind.  Loudspeakers are generally not a problem here - I have never heard two loudspeakers of different design sound the same (and please do not read more into that than intended - obviously I count different cables etc as the same design).  Amplifiers and especially things like cables are however another matter.  I accept low distortion amplifiers can sound different - but in my experience the differences are subtle.  I however am less sure about things like power chords - although I do respect people like Modwright who did use blind tests in evaluating supposed differences in power chords.  I simply want to see it used more widely.

Thanks
Bill

[rabbitz]

There's a lot of merit in what you are saying.

It's not viable with DIY loudspeakers to build 2 sets to do A-B or blind tests but I have tried doing tests in mono with each speaker having different components. I found it tended to confuse things (just me I suppose) and found it better to live with them for an extended period before doing any changes. My main speakers for example have been on going for 2 years and have had 5 major revisions, but the period between changes can be 6 months. I am fortunate to have good tweaking skills and know quickly what has to be changed to achieve a certain sound.

I've just found it better just to keep going until I achieve the target sound and you know when it happens.... woohoo.

[bhobba]

There's a lot of merit in what you are saying....

Thanks.

It's not viable with DIY loudspeakers to build 2 sets to do A-B or blind tests but I have tried doing tests in mono with each speaker having different components. I found it tended to confuse things (just me I suppose) and found it better to live with them for an extended period before doing any changes. My main speakers for example have been on going for 2 years and have had 5 major revisions, but the period between changes can be 6 months.

.
I am generally unconcerned about claims made of speakers - they vary so much.  Amplifiers IMHO posses more suptle differences so one should be careful to ensure bias is eliminated.  Cables etc, if they do have an effect, do so very suptly IMHO so blind testing there is a must.  For cables, even though I have never heard differences, I side with Jon Risch
http://www.videohifi.com/16_RISCH_ENG.htm
'I have personally maintained that the sonic differences between audio cables is of a subtle nature, and not of the "day-and-night" type of difference. However, when we are dealing with one’s personal home playback system, where the listener has become intimately familiar with it’s performance and overall sound, when something does change in such a system, they are going to notice it much more readily than a stranger would, or than someone participating in a blind test at an institute would. In the context of that persons playback system, a cable change might bring about a "night-and-day" difference, because it has pushed the performance of the system past the edge of disbelief of the playback event. If a new set of cables can allow the music to float free of the speakers, and achieve a sense of separate soundstage, while the old cables did not do this, the sound was "stuck" to the speaker locations, then to the owner/listener of that system, that is a "night-and-day" difference, even though in absolute terms, the sonic differences were small.'
The reason I believe him is he confirmed his views with double blind tests.  Without that I must admit I would be dubious of sonic differences between cables.

Thanks
Bill

[andyr]

... I am generally unconcerned about claims made of speakers - they vary so much.  Amplifiers IMHO posses more suptle differences so one should be careful to ensure bias is eliminated.  ...

Bill,

With respect, you are trying to "have your cake and eat it too"!  I'm not sure if you've picked it up but you're the ONLY one in this thread who says blind tests are a must when comparing components.  Rabbitz has said it's long term listening which is the key - so you can decide whether you can actually live with the new component, because short term blind testing might mask the "truth" (which is that it is fatiguing) whereas the short-term blind test says the treble is so revealing!  

Now you seem to be saying that blind testing is necessary with amplifiers because they posses subtle differences ... whereas the differences between speakers are so gross that blind testing is unnecessary!

Sorry - either blind testing is necessary in all comparisons or it is not!  Don't be arrogant in thinking that your ears are so perfect that what is a subtle difference (to your ears) might not be a HUGE difference to someone else ... just as YOU say different speakers make a huge difference, so blind testing is not necessary.

Regards,

Andy