Can You Trust Your Ears? By Tom Nousaine

[Fitzcaraldo215]

So the question is: what amplifier configuration or topology achieves what is required? These discussions always make it sound as though designs are ephemeral and stop working after a while, hence the need to be constantly listening, testing, revising, starting new amplifier manufacturing companies. Surely this is such a dull, mundane function, that somebody could just come up with a design that works satisfactorily et voila, problem solved forever.

Did the Quad 405 achieve what is required, in 1975? If so, why are people still re-inventing the wheel? Does a TI Class AB chip for $5 also solve the problem - possibly even better? Does a TI Class D chip do it even better?

Why is this still being discussed?

Why? The main theme is the ethos of progress underlying Western Civilization and all that entails. Progress brings the hope of something better, if not always the reality. Nothing created by a human being is perfect, so maybe progress will bring us something better. Does it always? No. Sometimes we get tail fins, with little else new, and then tail fins are taken away, still with little else new. But, you gotta let the manufacturers make a buck on the fluff if you also want them also to provide real progress where it matters, because that happens, too.

But, in audio as well as cars, even if makers knew how to make the perfect product, they would not because that would be bad, bad, bad for business. Fortunately, competitive pressures force manufactures in most cases to go all out. They cannot afford to lose market share to others who might not withhold a development that was truly better, even if only slightly. That is why hi def, now 4K TVs always get, like PCs, better, faster, cheaper. It is true in audio, as well.

One of the best quotes I ever saw was decades ago when Steinway & Sons was up for grab by investors. An owner said something like the biggest competition for the sale of new Steinways is old Steinways. Fortunately, though, the audio marketplace, like cars and so many other things, is not so slow-moving, settled and uncompetitive.

But, shifting to cars, another mature technology well over 100 years old, cars today are just so much better than they were even 10 years ago - safer, more reliable, better longevity, better MPG, better engine performance, less maintenance, longer oil change intervals, etc., etc., etc. If nothing else, in my lifetime, radial tires, antilock brakes and rear view cameras, to name a few, have saved many lives. Yes, new cars cost more, but with inflation accounted for, not really by too much considering they are much better at doing their job and have many truly improved features, huge list, along with some useless ones. Yup, a 1975 BMW will still get you from point A to B, if it is still running, which is unlikely. But, better? No way.

Audio is a fairly mature technology, so true progress is slow. Every now and then, there is a minor breakthrough or even a major one. But, nothing on this earth ever becomes perfect, so incremental development persists. Sometimes, products are developed that are hoped to make an improvement, but they don't really. Except, audiophiles can be convinced they are better, even if they sound only slightly different because we mostly all instinctively believe in progress and that newer = better, and a slight audible difference must, therefore, be "better". (Of course, there are always some retro-minded nay-sayers: "they don't make 'em like they used to", invariably with no true factual basis.). Cynical, negative possibilities aside, sometimes a new amp is actually slightly better incrementally: higher power and dynamics, lower distortion, better load tolerance, etc. Over the course of several years, those increments can cumulatively add up to something much more substantial and audible.

Audio was not perfect in 1975 and it is still not today. So, I have not tried it, but I am willing to bet that the 1975 Quad 405 amp can be bettered both measurably and audibly in DBTs, probably even at the same or even a better, lower inflation-adjusted price. That price advantage is because manufacturing technology and many component parts are cheaper via global sourcing, plus better design techniques and topologies have trickled down to lower price points as their development costs have been fully amortized.

Even assuming that 1975 amp sounds the same today as it did in 1975 - I doubt it - the fact is that speakers, input electronics and playback media sources have improved fairly substantially since then. What we thought we knew in 1975 with the wondrous LP, I think may not be applicable today with hi rez digital. Quad, a very reputable company, had absolutely no way to test their design then with the more revealing source material we have today.

Incidentally, I got a nice, nice 1985 Yugo I can sell you. Unfortunately, it is rusted out, but only a little teensy bit on a few panels, OK 5 or 6 of them, the tires are flat and it won't turn over, even with a recharged battery. But, it is a real classic!

Really, I think one of the most interesting and fun aspects of the audiophile hobby is being a smart consumer, cutting through the marketing BS, which is oh so subtle in many cases, and picking gear for the long haul that will be satisfying and revealing. But, I am in no hurry to chuck what I have. I have already chucked a lot of older stuff that frankly was not as good.

 

[NorthSky]

From my point of view, in the long run you can trust your ears, but nevertheless you can be fooled anytime.
It needs practice (as stated earlier, everybody has to learn to listen for evaluation purposes), it needs experience, noone of us knows what a recording should sound like from the beginning and noone knows which level of sound quality is possible overall. And it needs some selfreflection, but again, at lot of people have to rely on their "ears" - means hearing sense - for doing/improving their work and obviously they don´t do wrong most of the time.....

My ears are behind my over sixty years; I cannot make it past 13.3kHz so how can I trust them? And I'm being fooled no doubt, all over.
My search is for the musical orgasm each time I spin an album, preferably in the third dimension (multichannel).
I've been practicing synce 1962, I just need better practice, more money for better music reproducers in the right venues.
I have recorded my own music, I know musicians who have been recording all their life, we don't know how live music should sound because when we are recording live we are not in the audience but on stage. We need audio experts scientists to tell us if we can trust our old rusty from ancient experience ears and years.
All my life I've been looking for the secret passage into the next abundant life, and without trusting my ears I cannot find the door in the black hole.
Help me out and I'll buy you a beer next time @ the joint of the midnight pass.

Meanwhile ...

 

[tomelex]

In the end, given similar specs into a resistor load, comparing by measuring the spectrum analysis at the give speaker input at a give power level will show what the differences are of the two amplifiers, but it is that spectrum difference (which takes into account all kinds of differences) that is our measurement tool on any given load which shows mostly why they sound different (basically, the harmonic spray is strongest differentiator ).

And, if you simply look for the cleanest spectrum, that tells you the amplifier that is the cleanest (but both will distort the input to some degree no matter what).

It in no way, however, tells us which one sounds best, as we all respond to different things. But measurements are for telling reality (faithfulness to the recording...there is no other thing) and our ears are for telling us what we prefer. The musical sing song of the SET amplifier creates its own added richness and dynamics that are different than the solid state amp (and things the solid state amp just can not do with normal output topology).

 

[tomelex]

My ears are behind my over sixty years; I cannot make it past 13.3kHz so how can I trust them? And I'm being fooled no doubt, all over.
My search is for the musical orgasm each time I spin an album, preferably in the third dimension (multichannel).
I've been practicing synce 1962, I just need better practice, more money for better music reproducers in the right venues.
I have recorded my own music, I know musicians who have been recording all their life, we don't know how live music should sound because when we are recording live we are not in the audience but on stage. We need audio experts scientists to tell us if we can trust our old rusty from ancient experience ears and years.
All my life I've been looking for the secret passage into the next abundant life, and without trusting my ears I cannot find the door in the black hole.
Help me out and I'll buy you a beer next time @ the joint of the midnight pass.

Meanwhile ...

any frequencies you can not hear, simply do not matter, to you. At some point, audiophile just need to learn how to use an equalizer if they feel they want to "hear" more highs, etc. Take control, don't be controlled dear man.

 

[NorthSky]

any frequencies you can not hear, simply do not matter, to you. At some point, audiophile just need to learn how to use an equalizer if they feel they want to "hear" more highs, etc. Take control, don't be controlled dear man.

An equalizer is like a sound manipulator; it can destroy life (loudspeaker's drivers) or it can transform bad acoustics into seductive balanced sounds.
I'm from the later group; trying the achievement, everywhere I go. ...Even in the jungles listening to the wind, rain and every little animals that crawl across the sounds of running rivers .

 

[oivavoi]

Isn't there more to amps than just the frequency response? The subjectivist listeners I respect the most tell me that what they perceive as the biggest difference between amplifiers is dynamics and the ability to start transients really fast. This must surely also be connected to the load of the loudspeaker.

But I'm not sure on this. The question is once again whether one believes that long-term listening can reveal differences that short-term blind testing may not reveal.

Still curious to hear more details about the tests you performed, Jakob?

 

[Cosmik]

Someone says "If an amp's specs are good at all load impedances likely to be encountered then the amp is transparent".
I ask "If so, why do we need to keep re-inventing them? Can't we just find a design that works and put this boring functional block to bed?"
Everyone then says "Nothing is perfect. Audio progress is incremental. Amplifiers are like cars. We have to listen to them as well as measure them etc."

And so it goes round again...

In actual fact, no one wants it to be true that any type of amplifier or DAC is 'more than good enough'.

 

[fas42]

From my point of view, in the long run you can trust your ears, but nevertheless you can be fooled anytime.
It needs practice (as stated earlier, everybody has to learn to listen for evaluation purposes), it needs experience, noone of us knows what a recording should sound like from the beginning and noone knows which level of sound quality is possible overall. And it needs some selfreflection, but again, at lot of people have to rely on their "ears" - means hearing sense - for doing/improving their work and obviously they don´t do wrong most of the time.......

There's a very easy evaluation methodology - are the speakers 100% invisible or not? This behaviour occurs when the audible flaws of the system, not just the amplifier or speakers, are below a certain level - this happened to me 30 years ago, completely unexpectedly, and to this day is the number one criterion I use; extremely easy "to use", and 100% reliable.

This automatically also means you're only hearing the recording, and the only improvement then possible is to then hear still finer detail within the recording - the "what it sounds like" never changes, because it's locked into the mastering; the "window" is perfectly clear in every normal sense, but if you shine a strong light on it you may see fine dust particles, and what remains is to remove those now visible dust particles as the light intensity is increased, to whatever level suits.

 

[fas42]

Isn't there more to amps than just the frequency response? The subjectivist listeners I respect the most tell me that what they perceive as the biggest difference between amplifiers is dynamics and the ability to start transients really fast. This must surely also be connected to the load of the loudspeaker.

But I'm not sure on this. The question is once again whether one believes that long-term listening can reveal differences that short-term blind testing may not reveal.

It used to be that power supplies were a major flaw with most amps - a couple of decades ago most systems collapsed, badly, when asked to deliver decent SPLs; if you knew how to listen for, the clues, it was obvious that nearly every model wasn't capable - those "dynamics and the ability to start transients really fast" completely disappeared when the pressure was on.

These days it's much improved, there are a good assortment of amplifiers that can deliver in this area - the Bryston tested by the Swedish mob mentioned above I heard at an audio show, and was the best amplifier I've experienced to date - capable of driving conventional speakers to concert PA sound levels effortlessly, and with total integrity - impressive!!

In this case extremely short term listening tells you everything - just wind up the volume and see what happens - do you get a squashed, raucous mess; or an effortless intensity of 'pure' sound?

 

[Sal1950]

But measurements are for telling reality (faithfulness to the recording...there is no other thing) and our ears are for telling us what we prefer.

That puts a very complicated subject into a definitive short but sweet truth!

In actual fact, no one wants it to be true that any type of amplifier or DAC is 'more than good enough

The car comparison is pretty much spot on. We know what performance numbers are required to meet a desired goal. We have accomplished most all those performance goals with maybe the only real exception of energy efficiency. And like cars we have seen evidence of where high efficiency has come at the cost of performance.

 

[Sal1950]

As for my opinion about what makes an amp transparent, I believe it is actually simple. If all your conventional measures are good under load of the loudspeaker at the loudspeaker terminals you'll not be able to detect it. The most common issue is variable impedance of the speaker reacting with output impedance of the amp to alter frequency response enough to be heard. I believe the second most common issue (though I am less certain of this portion) is amps with different current output capability being driven into regions of slightly increased distortion or different distortion profiles at different points where large reactance levels require much more current from the amplifier power supply. Along with the manner in which various designs recover from such events likely differing.

So get the amps to do 20-20khz within .1 db, distortion of THD and IMD below .1% with low enough noise levels when actually driving the loudspeaker and I don't see how they can or will sound different. When such performance is reached with pre-amps or digital source devices it becomes transparent. Though not in recent years, I have measured a couple dozen amps hooked to my speakers (which varied over the years) just for frequency response at moderate levels using a simple wideband voltmeter and frequency generator at the speaker terminals. That mostly explained sound differences that matched perceptions right there.

In the end if amps sound different it can only be because they present a different signal to the speaker terminals. So it isn't some mystery.

Top shelf observations on the realities of amplifier design and sound thruout this thread D. I concur completely!

 

[RayDunzl]

Do I trust my ears?

Well, they are defective, or at least measurably below average in some respects, so, they miss things that other's ears might not...

They aren't trained, except from my years of listening to and (in the past) attempting to make music with various instruments.

But yesterday and today (maybe longer), "something" just wasn't right when I occasionally sat in the sweet spot.

It was like the levels weren't matched - left "louder" than right. Just a little... It bothered me though. The sensation kept occurring - radio, TV, CD. That isn't supposed to be happening.

But I couldn't see a reason. Balance on the preamp ok, DEQ2496 disabled, volumes on the MiniDSP channels matched, known filter downloaded to it...

I was beginning to wonder if my ears were having a bad day. That is not an impossibility.

time passed...

While taking a break from the latest terrorism analysis and opinions, prior to going back to some non-political and non-vocal music, I was fooling around making little high frequency hiss noises with my mouth, stretching to create ever higher bands of hiss (as measured on an RTA), and wondering why I could (at least seem to) hear hiss that only excited frequencies above what I can hear as a tone...

And suddenly my eye again fell upon the MiniDSP plugin and this time I noticed that I'd left a slight delay on the right side from some prior mucking around.

I eliminated the delay, and my antique system returned to what passes as perfection here.

Even though I don't trust my ears, they do a pretty good job at times trying to tell me something isn't good here.

Still wondering how I hear a broadband hiss that visually registers only within a range of frequencies where I can't hear a narrowband tone, though. That's a new one, for me.

Maybe I just think I hear it, since I'm the one making it.

 

[Blumlein 88]

Someone says "If an amp's specs are good at all load impedances likely to be encountered then the amp is transparent".
I ask "If so, why do we need to keep re-inventing them? Can't we just find a design that works and put this boring functional block to bed?"
Everyone then says "Nothing is perfect. Audio progress is incremental. Amplifiers are like cars. We have to listen to them as well as measure them etc."

And so it goes round again...

In actual fact, no one wants it to be true that any type of amplifier or DAC is 'more than good enough'.

I do. I'll take the $500 or even better $100 DAC which is audibly transparent. I can simply consider it a solved problem. Build quality and features would be all that is left. Something like the Teac NT503 which seems a fine enough DAC and offers built in useful network streaming features.

 

[Purité Audio]

Solid state amps have been acoustically transparent for the last thirty years, if their designers choose them to be, it is important that your amplifier is capable of driving your loudspeakers .
Keith

 

[Fitzcaraldo215]

Solid state amps have been acoustically transparent for the last thirty years, if their designers choose them to be, it is important that your amplifier is capable of driving your loudspeakers .
Keith

I do not disagree at all. But, I still think there are mostly tiny differences between SS amps into real speaker loads. Transparency comes in degrees, so it is not an absolute term and it does not mean they all sound quite the same, in my view. To some, those differences are inaudible or insignificant and not worth the time to worry about. To others, they seem important enough to futz about. Occasionally, those differences are more obvious with some amps, in the positive or negative direction, though still never of the magnitude of speaker/room differences.

So, in the mid 90's a once great local dealer said take these then $22k Krell KAS-2 Class A monoblocks I had been admiring home for a few days. I was not really in the market for new amps, but I was curious. I did have a much less expensive Krell KSA-150 at the time feeding my Martin Logan CLS's, a difficult load. The KSA-150 had been carefully selected by ear about 5 years earlier. I do not think I was deluding myself to feel that there was obviously better bass performance, as well as other, subtler improvements with the KAS-2. The bass with the CLS's had been anemic, no matter what, even with other amps tried previously. The KSA-150 was perfectly capable of sounding very good, but the KAS-2's were just obviously even better especially in improving that bass. This was to me not a tiny difference. The bass was still not ideal, but it was much better. Today, I could measure, but I was unable to back then.

Even with a steep discount on the demo units, the price was stratospherically more than I had ever dreamed of spending. But, I did it. Fortunately, it worked out well. I owned them happily, getting > 30% back on a cash resale 15 years later to the same dealer! I calculate that owning them cost me about $500/year, which is not bad in my book, and well worth it.

The still current replacement is a Spectron Musician III Mk II Class D, which I auditioned carefully in my home alongside the KAS-2's and a few other amps I borrowed locally. Different ML speakers this time, hybrids without the anemic bass. This time the amp differences were much less pronounced in most cases, so I "upgraded downward" from the expensive Krells to the cheaper Spectron, going Class A to D in the process. They were very close, but I slightly preferred the Spectron, which I thought sounded a bit more "transparent".

 

[Cosmik]

I do not disagree at all. But, I still think there are mostly tiny differences between SS amps into real speaker loads.

Where is the 'science' in this? Is it an accepted fact that a typical competently-designed amplifier (I'm thinking $5 TI integrated circuit or typical Sony amp, say) 'loses it' with real speaker loads? If so, we should be homing in on that, rather than measuring THD with sine waves and leaving a distinct gap in our knowledge of what the amp is doing.

Transparency comes in degrees, so it is not an absolute term and it does not mean they all sound quite the same, in my view. To some, those differences are inaudible or insignificant and not worth the time to worry about. To others, they seem important enough to futz about. Occasionally, those differences are more obvious with some amps, in the positive or negative direction, though still never of the magnitude of speaker/room differences.

I have a terrible feeling that you are referring to sighted listening. I would much rather see objective measurements with traces where you can point and say "See, it lost control of the bass right there" - if such differences exist.

 

[Fitzcaraldo215]

Where is the 'science' in this? Is it an accepted fact that a typical competently-designed amplifier (I'm thinking $5 TI integrated circuit or typical Sony amp, say) 'loses it' with real speaker loads? If so, we should be homing in on that, rather than measuring THD with sine waves and leaving a distinct gap in our knowledge of what the amp is doing.

I have a terrible feeling that you are referring to sighted listening. I would much rather see objective measurements with traces where you can point and say "See, it lost control of the bass right there" - if such differences exist.

Gosh, where is the science that says all SS amps measure the same into real speaker loads?

Mea culpa. If it was not obvious, then, yes, I confess I was offering sighted, subjective anecdotes. My friendly local audio scientist was not available for these evaluations. So, I offer these anecdotes only for those interested, and I confess they do not rise to the level of science. But, was it implied that they did?

 

[Cosmik]

Gosh, where is the science that says all SS amps measure the same into real speaker loads?

It's control theory. Is the amp meeting the requirements of "hi-fi"? If so, then yes, they all measure (and therefore sound) the same. (Sch**t amps are obviously an exception). If there's some doubt about it, we should examine the likely problem areas rather than just listening to them and saying they sound different.

There's "the same" and "the same" - it will always be possible to keep zooming in until differences show up - even with the same amp playing the same signal twice, but surely we can be pragmatic about that.

 

[Fitzcaraldo215]

It's control theory. Is the amp meeting the requirements of "hi-fi"? If so, then yes, they all measure (and therefore sound) the same. (Sch**t amps are obviously an exception). If there's some doubt about it, we should examine the likely problem areas rather than just listening to them and saying they sound different.

There's "the same" and "the same" - it will always be possible to keep zooming in until differences show up - even with the same amp playing the same signal twice, but surely we can be pragmatic about that.

Sorry, there seem to be several important steps missing, making it impossible to understand or to accept your logic. Maybe I am lost here, because having worked with detailed "requirements" in fields other than audio, it has been quite pervasive that there were different approaches that were not "the same", but which still met the requirements, as far as they went.

The "requirements of hi fi" aren't universally and rigorously defined, as far as I am aware. So, you have not proven your point. I am not saying I have proven anything either, but then I was not trying to.

 

[Purité Audio]

The only differences in sound quality between low distortion solid state amps is when one particular amp cannot properly drive the loudspeaker in question.
Try comparing, unsighted two amps with similar specification into the same loudspeakers.
Keith