Does It Really Sound The Same?

[upstateguy]

 
Quote:

The beauty of the scientific method, and evidence based reasoning is that my opinion makes no difference. If different components do have a sonic difference, 
then independent observers should be able to reliably reproduce those differences, to a statistically significant degree.
 
If the assertion is that component A and B sound different, then it can easily be tested, by measuring a system using component A, then replacing component A with component B , and re-measuring , and checking the differences (if any). How hard is that? And we learn something in the process.

The assertion was in fact, that all dacs sound the same.
 
Therefore, doesn't that claim have to be proved by the methods you mentioned above and not accepted blindly? <--- Audio DiffMaker files please, or it isn't true.
 
Another thing from your previous post was that you seemed to feel all dac chips sound the same, if you don't include the analog section in the dac, but it seems that a dac can't be a dac without an analog stage... So why not say all analog stages sound the same too? Because they may not.
 
And if the analog stages do indeed sound different from each other then all dacs can't sound the same.
 
All I'm doing is questioning the blanket statements circulating around the back of the bus, in the same way we question the statements coming from the front.
 


Quote:

Everybody interested in this argument should read this article:
 
http://sound.westhost.com/amp-sound.htm
 
It's about why amplifiers may sound different from each other, and possible ways to measure that.
 
Under a very easy load, many amplifiers do indeed sound the same. But quite a few headphones and speakers present widely varying impedance curves. Others have very high voltage or current requirements, such as electrostatic or planar headphones. I think the "all amps sound the same" argument is an overreaction to those audiophiles who claim to hear extremely wild differences between amplifiers and personify their electronics (for an example of this, read any issue of TAS or Stereophile, or 6moons, or... any audio publication). While these descriptions are the product of a dubious "reviewer's" imagination and the totally unscientific test procedure, there are real differences in how amplifiers perform with different loads. If we all used one speaker or one headphone, then yeah, all well-designed amps would sound the same. But each transducer has very different power requirements.
 
I would like to hear from people who actually design amplifiers, such as Kevin Gilmore, Jason Moffat, or Pete Millet. Their opinions would add a lot to this discussion.

I wouldl too.  Especially Kevin Gilmore.
 
 
Quote:

Okay, there are measurable differences in transistors, opamps - circuit design can affect things, the length of hookup wire can affect things - there are tonnes of factors. But the thing is, modern equipment is, as a rule, well designed. Regardless of the approach the designer took, in the end if all the numbers are well below the threshold of audibility, there is no reason to suspect that having the numbers in a different position below the threshold of audibility would do anything.
 
Not everything "sounds the same", but if it is well designed it will. If I use an awful quality power supply consisting of the cheapest regulator I can find, there might be audible differences. But that's not good design. If I use a weird circuit topology that results in a stupidly high output impedance in an amp, there might be audible differences. But that's not good design.
 
Things do measure differently, but the differences between one good component and another are generally small. Additionally, when the base design is well thought through, it becomes less reliant on extraordinarily expensive and esoteric components. Opamps and transistors are just tools. It is the designer's job to choose and utilise his tools appropriately. If he has done his job, any differences should be well below the threshold of audibility.
 
PS: "Correctly Implemented" probably means here that all the relevant measurements declare that distortion, frequency response and time based error (and channel imbalance) are all far below audible levels. If one DAC that achieves this uses a switching PSU, another a linear PSU, why would it matter? They have both achieved the same goal. Certainly, the designer using the linear PSU may have had an easier time of it making such a well-measuring piece of kit, but in the end, they have both done the same thing.
 
EDIT: @ tvrboy: Hence the additional statement that: All amplifiers designed to alter the sound as little as possible, operated within the operating constraints within which they were designed to operate, will sound the same.
The problems looked at in that article are easily addressed with good design.
 
 

 
Hi Willlakan
 
You have a good head on your shoulders, but "Correctly Implemented" and "well designed" are judgment calls, not scientific facts.  As I write this an engineer by the name of nwavguy is busy ripping apart 3 channel amp designs on his blog.  According to him, 3 channel amps are not well designed or correctly implemented.  On the other side of the coin is AMB who designed quite a few 3 channel amps.  Who is right?  The engineer making measurements or the designer?
 
Another thing is that is becoming a recurrent theme with me is that with all these different things you mentioned above, components, circuit design etc, which all have measurable differences, how could it be possible that assemblies of these parts, from different manufacturers and put together by different people can end up all sounding the same?
 
I can understand that a piece of wire is nothing more than a piece of wire, regardless of what it's made from, and has no inherent sound of its own, but I'm not so sure the same is true about complex devices made from components that have measurable differences between them.
 
As I said above, if you are claiming that all "Correctly Implemented" devices are going to sound the same, please give us some Audio DiffMaker files so that we may here this for ourselves.
 
 

 
Quote:

Read the article I linked, that gives some very good possible answers to your question. Of course, I do agree that most "differences" people hear are either 
 
1. Placebo
2. Wishful thinking
3. Change in seating position (comb filtering effects)
4. Not level matching
 
Again, I agree that all amps designed for the same purpose will sound the same, excluding tube amps. But you have to keep in mind the amp designer doesn't know what kind of speakers/headphones will be connected, so compromises have to be made.
 
Oh yeah and it's Jason Stoddard, not Moffet! Oops!

OK, you're making a claim that all amps will sound the same and I'm fine with that, but please provide some diffMaker proof so we might evaluate it too.
 


Quote:

I did scan it and have read it in the past, but it is worth another read.
 
My amp is a hybrid tube and solid state. Where does that fit into 'all amps sound the same'?

Hey Proggy
 
If you consider that all amps sound the same, then yours will sound the same too as long as it fits within the original criteria established by Stereo Review for their amp test.
 
On the other hand, I wanted to address what you said earlier about why people hear differences and others don't.  First, the deeper I look into this, the more I'm starting to think that there are differences to be found everywhere.  I suspect that the more similar the designs the less the differences, but measurable differences between components bothers me.  It means that things can't sound the same unless it makes no difference what- so-ever what the component compliment of an amp or dac design might be.... and I don't believe that.
 
My first dac was a Lite DAC-AH.  That dac had 8 paralleled Phillips TDA-1543 Dac chips, a CS 8414 receiver and Burr-Brown op amp.  Is this as good as it gets?  Or is the new ESS 32 bit Sabre chip even more resolving?  It's too easy to say that all dacs sound the same without the same significant proof we demand from the people who hear differences between cables.
 
Back to your question.....  perhaps it's the weakest link in the chain that prevents some people from hearing the differences various components make.  Maybe an amp that isn't resolving enough to hear the differences between dacs, or a dac that isn't delivering a high enough quality signal to be able to demonstrate differences between amps, or some other factor like a usb transport or an on-board computer audio chip?????? 
 
You asked the question but I know it's rhetorical, so what is your take on why some people hear differences and some don't?
 
E

 

[tmars78]

Quote:

 

Quite possibly a case of cheap clones with fake parts inside. I've seen fake opamps, fake capacitors, fake ALPS pots, and so on floating around on eBay.
 

He said all of the SAME parts. So if they are the same parts, it should sound exactly the same. So if it doesn't? See below:
 


Quote:

That sounds like it is caused by the power of the Grado name! Seriously, is name and image really not an influence on sound?

 

 

[Yoga Flame]

 
Quote:

He said all of the SAME parts. So if they are the same parts, it should sound exactly the same. So if it doesn't? See [Prog Rock Man's post]:
 

I agree that a brand name can cause perceived improvements in sound, and the lack thereof can cause perceived loss of quality, even with identical parts.
 
My point was rather that those who bought cheap clones from unknown eBay sellers and such may have thought that the component parts were identical, but in fact they were fakes made to look like the real thing. The clone sellers themselves may not have known either, and had simply thought they scored a nice bargain from their local (fake) electronics parts supplier.
 

 

[tmars78]

Quote:

 

I agree that a brand name can cause perceived improvements in sound, and the lack thereof can cause perceived loss of quality, even with identical parts.
 
My point was rather that those who bought cheap clones from unknown eBay sellers and such may have thought that the component parts were identical, but in fact they were fakes made to look like the real thing. The clone sellers themselves may not have known either, and had simply thought they scored a nice bargain from their local (fake) electronics parts supplier.
 

 
Gotcha. Yeah, I see a lot of fakes online, and you really have to be careful what you are buying. There are always people out there looking to make an not so honest buck. I think that even goes for(some) "higher" end companies. 
 
 

 

[Willakan]

Interesting that you bought up 3-channel amps. Before I continue I must make a distinction between two discrete events that NwAvGuy has virtually merged. He measured a Mini3 3-channel amp and found flaws in some of the measurements - which were strongly contested by the designer. He then attacked three channel amps from a purely theoretical standpoint.
However, his attack centred aruond the fact that three-channel amps must make unneccessary compromises and that it is a very inelegant solution to a simple problem. It is a critique of the design, yes, but it does not declare all amps using the design useless. If the M^3 still manages to measure well, then it has acheived this in spite of its flaws and must be considered a successful amp, if an inelegant design. Whether a design is elegant is judgement, whether it works properly, whilst there is no perfect boundary (see below) is not so much.
 
The concept of them sounding the same is not reliant upon null testing - it simply is based on the measurements. It is true that there is no set boundary where we say "Yes! This is a good solid state amp" (leaving tube amps and designs that alter the sound out of it, as they are designed to do so). However, when every measurement is vastly beyond the threshold of audibility, it is not unreasonable to say it is a well engineered amp. Take the hypothetical amp I now place before you - I have chosen measurements which are commonplace for good solid state amps:
 
Frequency Response: -0.1db at 20khz, -0.1db at 20hz. 0.1db is considered to be an inaudible difference - indeed many holding that listeners must be trained to consistently notice 1db differences in volume. Indeed, the lack of musical information in the high frequency bands suggests that far greater roll-offs are inaudible - for example, the Yulong D100 DAC includes a switch that introduces a 3db rolloff at 20khz, starting at 16khz. Everyone who reviewed it declared this inaudible. Hence I feel relatively confident in stating that a rolloff of an inaudible size, in a hard-to-hear and largely unused frequency band, is inaudible.
 
Distortion: Without going into the intricacies of THD and IMD measurements, 1% THD is considered hard to hear - and does not manifest as distortion in the traditional sense (else Stereophile reviewers of esoteric tube amps would be very upset) . Is anyone seriously suggesting that the 0.0005%THD of a good DAC or the 0.001% THD of a decent amp is ever going to be audible?
 
Noise: SNR ratios of over 100db are relatively easily acheived, exceeding the theoretical noise floor of 16 bits. Has anyone complained of hearing quantization noise on their CDs?
 
Crosstalk: Again, easily minimised and very rarely found at problematic values. Hell, in some designs it is below the noise floor.
 
Jitter: A gigantic red herring - jitter is at inaudible levels in all but the most horribly flawed systems.
 
Dynamic Range: The bottleneck here is the recording, not the equipment.
 
Hence I feel relatively confident, when faced with sets of excellent measurements, to conclude that the systems from which they are taken produce sound that is effectively identical. The reason null tests do not abound is that the sort of people with the equipment and expertise to perform them likely feel satisfied that they are not required.

 

[Prog Rock Man]

Quote:

 
 
........

Hey Proggy
 
If you consider that all amps sound the same, then yours will sound the same too as long as it fits within the original criteria established by Stereo Review for their amp test.
 
On the other hand, I wanted to address what you said earlier about why people hear differences and others don't.  First, the deeper I look into this, the more I'm starting to think that there are differences to be found everywhere.  I suspect that the more similar the designs the less the differences, but measurable differences between components bothers me.  It means that things can't sound the same unless it makes no difference what- so-ever what the component compliment of an amp or dac design might be.... and I don't believe that.
 
My first dac was a Lite DAC-AH.  That dac had 8 paralleled Phillips TDA-1543 Dac chips, a CS 8414 receiver and Burr-Brown op amp.  Is this as good as it gets?  Or is the new ESS 32 bit Sabre chip even more resolving?  It's too easy to say that all dacs sound the same without the same significant proof we demand from the people who hear differences between cables.
 
Back to your question.....  perhaps it's the weakest link in the chain that prevents some people from hearing the differences various components make.  Maybe an amp that isn't resolving enough to hear the differences between dacs, or a dac that isn't delivering a high enough quality signal to be able to demonstrate differences between amps, or some other factor like a usb transport or an on-board computer audio chip?????? 
 
You asked the question but I know it's rhetorical, so what is your take on why some people hear differences and some don't?
 
E

The different results that you get between sighted and blind testing suggests that in sighted testing, where big differences are reported people are being influenced by outside factors. In sighted testing where people say they cannot hear a difference, they are not being influenced in the same way. Those people are producing the same results as if the test is blind.
 
Arguably those who cannot hear a difference could have 'talked themselves out' of hearing a difference, a reverse placebo if you like. Or those who have heard a difference have 'talked themselves into' hearng a difference, placebo as it is often referred to. (I hate that term)
 
So, to get a definitive answer as to who is right we need to measure DACs and find if they produce audibly different signals. So far, from what I have read, most DACs do not produce audibly different signals, but there may some that do.
 
 

 

[upstateguy]

Quote:

Interesting that you bought up 3-channel amps. Before I continue I must make a distinction between two discrete events that NwAvGuy has virtually merged. He measured a Mini3 3-channel amp and found flaws in some of the measurements - which were strongly contested by the designer. He then attacked three channel amps from a purely theoretical standpoint.
However, his attack centred aruond the fact that three-channel amps must make unneccessary compromises and that it is a very inelegant solution to a simple problem. It is a critique of the design, yes, but it does not declare all amps using the design useless. If the M^3 still manages to measure well, then it has acheived this in spite of its flaws and must be considered a successful amp, if an inelegant design. Whether a design is elegant is judgement, whether it works properly, whilst there is no perfect boundary (see below) is not so much.
 
The concept of them sounding the same is not reliant upon null testing - it simply is based on the measurements. It is true that there is no set boundary where we say "Yes! This is a good solid state amp" (leaving tube amps and designs that alter the sound out of it, as they are designed to do so). However, when every measurement is vastly beyond the threshold of audibility, it is not unreasonable to say it is a well engineered amp. Take the hypothetical amp I now place before you - I have chosen measurements which are commonplace for good solid state amps:
 
Frequency Response: -0.1db at 20khz, -0.1db at 20hz. 0.1db is considered to be an inaudible difference - indeed many holding that listeners must be trained to consistently notice 1db differences in volume. Indeed, the lack of musical information in the high frequency bands suggests that far greater roll-offs are inaudible - for example, the Yulong D100 DAC includes a switch that introduces a 3db rolloff at 20khz, starting at 16khz. Everyone who reviewed it declared this inaudible. Hence I feel relatively confident in stating that a rolloff of an inaudible size, in a hard-to-hear and largely unused frequency band, is inaudible.
 
Distortion: Without going into the intricacies of THD and IMD measurements, 1% THD is considered hard to hear - and does not manifest as distortion in the traditional sense (else Stereophile reviewers of esoteric tube amps would be very upset) . Is anyone seriously suggesting that the 0.0005%THD of a good DAC or the 0.001% THD of a decent amp is ever going to be audible?
 
Noise: SNR ratios of over 100db are relatively easily acheived, exceeding the theoretical noise floor of 16 bits. Has anyone complained of hearing quantization noise on their CDs?
 
Crosstalk: Again, easily minimised and very rarely found at problematic values. Hell, in some designs it is below the noise floor.
 
Jitter: A gigantic red herring - jitter is at inaudible levels in all but the most horribly flawed systems.
 
Dynamic Range: The bottleneck here is the recording, not the equipment.
 
Hence I feel relatively confident, when faced with sets of excellent measurements, to conclude that the systems from which they are taken produce sound that is effectively identical. The reason null tests do not abound is that the sort of people with the equipment and expertise to perform them likely feel satisfied that they are not required.

 
The problem with hypothetical things is that they are hypothetical.

A few threads ago I would have written exactly what you did, but I 'm having a hard time coming to terms with the effect different components might be able to exert on the sound of a device. 
 
Take two similar amps or dacs and give one a switching PS and the other a well regulated linear.  Are they going to sound the same?  If the answer is no, then all dacs and amps do not sound the same.
 
Can the sound of opamp based amps or dacs be altered by exchanging the opamps?  If the answer is yes, then all dacs and amps do not sound the same.
 
And, at the most basic level, can the sound of a c-moy be influenced by using different opamps?  Tangent seems to think so and he's not alone.  Now what???

 


Quote:

The different results that you get between sighted and blind testing suggests that in sighted testing, where big differences are reported people are being influenced by outside factors. In sighted testing where people say they cannot hear a difference, they are not being influenced in the same way. Those people are producing the same results as if the test is blind.
 
Arguably those who cannot hear a difference could have 'talked themselves out' of hearing a difference, a reverse placebo if you like. Or those who have heard a difference have 'talked themselves into' hearng a difference, placebo as it is often referred to. (I hate that term)
 
So, to get a definitive answer as to who is right we need to measure DACs and find if they produce audibly different signals. So far, from what I have read, most DACs do not produce audibly different signals, but there may some that do.
 
 

I know, I know, I know, but I'm starting to think that there's something fundamentally wrong with making blind judgments.  I've certainly had enough blind testing to agree with what you're saying, but the component issue bothers me to the point where I find it very hard to say that all dacs and amps sound the same without saying all the components  they are made from sound the same.... and I'm not sure I can do that.
 
Why is it not possible for the new 32 bit ESS Sabre chip to have more resolution than the old Phillips TDA-1543 chips and therefore a difference in sound? 
 
Let me ask you straight out, do you believe that my old DAC-AH with it's 8 Philips chips sounds exactly like one of the new 32 bit Sabre chip based dacs?  Or that my Pico sounds like my Northstar?  I know what the answer should be according to our party line, but I'm really hard pressed to get on board with it, because the Pico does not sound like the Northstar.
 

 

[Willakan]

I see what you're getting at now and will address your points in the order that you made them.
Your concerns about the sounds of opamps/switching PSUs:
I understand I'm nitpicking at your terminology here, but a PSU does not have a "sound." A PSU obviously provides power and they obviously vary in the quality of power provided. This can affect the sound, but the very idea of thousands of components all with "sounds" of their own interacting understandably makes the "Measurements are everything" approach look somewhat foolhardy.
Perhaps I can suggest another way of looking at it - using DACs as an example:
At the core of your DAC you have the DAC chip (or chips for that matter). Keeping NOS DACs out of it (in the same way tube amplifiers are not relevant to "All good solid state operated within its limits sounds the same" argument) this will be implemented in a vaguely predictable way. There are tonnes of chips to choose from, many of which measure above and beyond what is required by some considerable margin. Assuming a DAC was merely a DAC chip, the overwhelming majority of DACs would sound exactly the same.
 
Of course, there are other factors which you have rightly highlighted. However (and don't take this as patronising) you're still thinking of these parts as having a "sound." Assuming they haven't been designed to have a sound, which in a DAC they shouldn't, it is better to think of these parts as a source of potential degradation. For example, if I use resistors with 20% tolerances I am going to get some pretty impressive channel imbalance - get ones with 1% tolerances and it's not much of an issue.Considering the PSU, it aims for clean power in abundance. The targets are clear - the designer can make compromises in attempting to satisfy one set of design criteria over another, but if that results in any of the numbers being bad enough (power supply drops out of regulation under heavy load, power supply is noisy, power supply fluctuates considerably) to even come within a mile of audibly affecting the  equipment the designer hasn't done his job. 
 
Besides, a power supply is only a potential source of degradation of the signal. Circuits vary dramatically - in a well designed piece of kit it is extremely unlikely that the power supply will cause anything approaching audible problems. A good circuit is not extremely sensitive to the slightest power supply problem. To give a real world example, the DACmagic power supply is nothing hugely special, from my understanding. Small anomalies from the power supply can be seen in the measurements, but these are far, far below the levels of audibility. Upgrading it with a better power supply (more difficult than you would think, as the AC rectification is all on the circuit board) would not yield an audible difference.
 
Again, with the analog output stage, you are likely to have opamps. Opamps are another potential source of distortion and other "corruption" of the sound. Hence, we choose opamps that measure above and beyond any reasonable level. For example, the NE5532s are used in the analog stage of the Benchmark DAC - they undoubtedly add small amounts of distortion, but not enough to be audible. They do not add a "sound", they do a job. Many audiophiles attacking opamps as ruinous of audio point to the fact that many opamps were not designed exclusively for audio applications. However, if they do the job, who gives a proverbial? Opamps are designed through mathematics and simulation and it is probably a source of endless amusement/offense to their designers that people suddenly declare their opamps "roll off the treble" or something. (Alternatively, the designers don't care)
 
The way to look at it is that you have a piece of equipment with every component striving towards an abstract ideal - no channel imbalance, zero distortion of any sort, a signal to noise ratio of infinity...and so on. Thinking of components as each having their own "sound" is simply audiophile dogma - from the same people who would tell you that the table upon which you place your solid state amp has a "sound" too. Electronics being a rather well understood area of science, making a DAC that gets close enough to these abstract ideals to be effectively audibly perfect, whilst not exactly trivial, is not some mystical science which will only yield the best results when you have bought some $10k monstrosity.
 
Regarding your observations on different DAC sounds, I am not familiar with the specs of the models to which you refer. Reasons for differences:
1. One of the DACs is old enough and uses antiquated enough chips to actually be audibly different.
2. Your comparisons between them are not perfectly volume matched. DACs have quite large variations in output levels and changes in volume are regularly perceived as all sorts of things (but you don't need me to tell you that).
3. You expect differences.
 
Attributing "sounds" to everything is an audiophile trait, not how circuits are designed.

 

[Currawong]

Quote:

It would, but bear in mind they also sell amplifiers. So it is unlikely they will support the 'all well made amps will sound the same' argument. It is in their interests to say amps sound different and their one is better.

 
I have to correct this: Kevin Gilmore does not, and never to my knowledge has sold any amplifiers for profit (and is not a Member of the Trade). If he discusses the reasons for the differing performance of amps, it would be from an engineering perspective.
 
I gather that Tyll Hertsens has considered measuring headphone performance with different amps as any differences would be readily apparent then. It would be worth looking out for that.  From my own experiences though, ignoring tonal/frequency response differences in amps caused by the circuit or tube, people who listen at relatively low volume levels may find little, if any perceivable difference between different amps. It is more likely that someone who listens quite loud would be able to pick up changes.  However, the differences at higher volumes between something like an iPod and a regular headphone amp (even using the iPod as a source) can be quite apparent with some headphones.
 
 

 

[Willakan]

True, but no-one is trying to argue that the ipod is all you need as a headphone amp. The flaws of the ipod's amplifier section are quite well documented (high output impedance for one). (Likewise, no-one is suggesting that equipment that purposefully distorts or modifies the signal will sound the same).

 

[Currawong]

It would be interesting to measure what was going on between amps I tried where, with HD-600s I could clearly make out a different width in the soundstage with some recordings. I don't know the technical details of the amps I had at the time though. With the lesser amp on a live recording, it sounded as if one were standing at the rear, whereas with the more expensive amp, more in the middle. I imagine there are quite reasonable electrical explanations for the difference in performance in that case. The circuits in both amps were different.

 

[upstateguy]

Quote:

I see what you're getting at now and will address your points in the order that you made them.
Your concerns about the sounds of opamps/switching PSUs:
I understand I'm nitpicking at your terminology here, but a PSU does not have a "sound." A PSU obviously provides power and they obviously vary in the quality of power provided. This can affect the sound, but the very idea of thousands of components all with "sounds" of their own interacting understandably makes the "Measurements are everything" approach look somewhat foolhardy.
Perhaps I can suggest another way of looking at it - using DACs as an example:
At the core of your DAC you have the DAC chip (or chips for that matter). Keeping NOS DACs out of it (in the same way tube amplifiers are not relevant to "All good solid state operated within its limits sounds the same" argument) this will be implemented in a vaguely predictable way. There are tonnes of chips to choose from, many of which measure above and beyond what is required by some considerable margin. Assuming a DAC was merely a DAC chip, the overwhelming majority of DACs would sound exactly the same.
 
<snip>
 
Again, with the analog output stage, you are likely to have opamps. Opamps are another potential source of distortion and other "corruption" of the sound. Hence, we choose opamps that measure above and beyond any reasonable level. For example, the NE5532s are used in the analog stage of the Benchmark DAC - they undoubtedly add small amounts of distortion, but not enough to be audible. They do not add a "sound", they do a job. Many audiophiles attacking opamps as ruinous of audio point to the fact that many opamps were not designed exclusively for audio applications. However, if they do the job, who gives a proverbial? Opamps are designed through mathematics and simulation and it is probably a source of endless amusement/offense to their designers that people suddenly declare their opamps "roll off the treble" or something. (Alternatively, the designers don't care)
 
<snip>
 
Regarding your observations on different DAC sounds, I am not familiar with the specs of the models to which you refer. Reasons for differences:
1. One of the DACs is old enough and uses antiquated enough chips to actually be audibly different.
2. Your comparisons between them are not perfectly volume matched. DACs have quite large variations in output levels and changes in volume are regularly perceived as all sorts of things (but you don't need me to tell you that).
3. You expect differences.
 
Attributing "sounds" to everything is an audiophile trait, not how circuits are designed.

OK, now let's discuss your points but in a much more simplified manner.
 

1. a PSU does not have a "sound."

 
I don't think that a power supply or a component has a sound, what I implied was that a power supply or component can affect the sound, and if that is true not all devices with PS will sound the same.
 

1. Keeping NOS DACs out of it

 
Why?  I have a Constantine + dac that is NOS as well as my old DAC-AH, and if I don't throw the switch for 192 upsampling, isn't my Stello DA100 a NOS dac?  You'll have to help me out here because all I have is a layman's understanding this.
 

1. Assuming a DAC was merely a DAC chip, the overwhelming majority of DACs would sound exactly the same.

 
First you would have to assume that all dac chips would impart the exact same end product sound to every device they are used in regardless of implementation.  But, a dac chip is not a dac....  so I'm going to stop here.
 

1. Opamps are designed through mathematics and simulation

 
OK, let's talk about opamps.  Let's go back to the most basic c-moy.  I'm going to ask you Straight out:  Can using different opamps change the sound of the c-moy?  Is Tangent's opamp write up complete BS?  http://tangentsoft.net/audio/opamps.html     
 
Regarding your observations on different DAC sounds, I am not familiar with the specs of the models to which you refer. Reasons for differences:
1. One of the DACs is old enough and uses antiquated enough chips to actually be audibly different. <---- I think you have just proved my point
2. Your comparisons between them are not perfectly volume matched. DACs have quite large variations in output levels and changes in volume are regularly perceived as all sorts of things (but you don't need me to tell you that).  <---- Even with reversed volume levels I can't get my DAC-AH or Pico, to have the same quality* as my NorthStar. No matter what I do, they don't sound the same.
3. You expect differences.  <---- Guilty as charged, but many times the result is not what I expected.
 
 
* The quality I'm referring to is similar to (but not exactly the same as), the spacial and resolution differences between conventional headphones like the 880s and 650s and the new angled driver headphones like the T-1s.  But let's not make an issue of volume balancing.  I know how important it is.
 
Edit:  <snip> to save some bandwidth

 

[Willakan]

The reason I kept NOS DACs out of it is that many NOS DACs measure horribly - I would expect this to result in oft-audible differences. Rather like tube amps or vinyl, they introduce pleasant distortions. I would imagine there are NOS DACs out there that measure reasonably well, but that would be in spite of their implementation IMO. The chief claim to fame of NOS DACs is square wave reproduction - square waves almost never actually occuring in music and being indistinguishable from sine waves above a certain frequency. I'm not a NOS fan

.
 
Regarding DAC chips, they can be implemented in different ways - the aformentioned NOS approach, for example. However, the overwhelming majority of DACs are implemented in a way that does much the same thing as other DACs. I might have multiple chips, one per channel, to improve SNR or I can resample to various different frequencies. However, these differences in approach generally result in small differences which are unlikely to be audible - with the exception of the minority approach such as eliminating oversampling. So I can say the majority of vaguely modern DAC chips, implemented in vaguely conventional ways, sound the same. My original statement was perhaps a little too sweeping, but not by that much.
 
Opamps is a bit of a horny one for me personally. Tangent's opamp sound signature analysis has several aspects of it which makes it inapplicable to opamps as used in DACs:
1. The cmoy is a design which drives a difficult load (a headphone) directly with an opamp. This means that factors that would normally be dealt with with MOSFET buffers and the like in better amps can affect the opamp itself - for example, many cheap cmoys have uneven frequency responses.
2. Opamps, even in the simplest of circuits, are not neccessarily drag-n-drop. The "opamp rolling" which many people participate in always makes me feel slightly uneasy, because dropping in one opamp which has vaguely similar specs and hoping that the circuit won't mind is not neccessarily a good idea. However, I find it extremely unlikely that Tangent didn't take this into account - indeed, he speaks of oscillation and the like in his article.
3. In the end, it was a sighted test, whilst it is also unclear whether the volumes were matched. Anyone who has done blind testing knows how monstrously obvious differences can suddenly disappear.
 
However, in the end we are not looking at the measurements of the opamp - we are looking at the measurements of the whole. If the designer has used some weird and wonderful opamp and still managed to turn out a measurably exemplary product, bully for him!
 
As to your closing points, no-one is suggesting that every DAC and amp under the sun sounds exactly the same. The title of the other thread was more a provocative point to get people posting. However, there is no reason why a Benchmark should sound different to a DACmagic, nor that to the $6000 dollar dcs Puccini - as they all measure very well. Hell, you could probably go considerably cheaper than the DACmagic. If your point was that not every conceivable DAC and amp will sound the same, consider yourself vindicated

 
Regarding differences as expected/not expected, it's difficult to draw anything from this as to their nature. Perhaps you were subconciously hoping for this cheaper DAC to turn out better than it's peers. Alternatively, there were real differences that would also be easily measurable as significant - it seems unlikely, but not having the measurements of any of those products in hand, I cannot instantly dismiss it. However, were there significant differences in the measurements from what was expected (0.5% THD for example) then I could safely say that rather than one of the DACs being special, the others were merely inferior to what you would expect. Again, it's difficult to draw any conclusions from your specific example.

 

[bigshot]

In order for complex devices like DACs and Amps to sound the same, the components that make them up must also sound the same.

You're starting from the wrong premise. All components don't have to sound the same if they are all *calibrated* to sound the same.

DACs are supposed to adhere to redbook standards. That means a flat frequency response from 20Hz to 20kHz with a dynamic range of 90dB. It isn't difficult to design digital audio that performs to specs with an inaudible level of distortion. The same goes for preamps or amps. This covers the full spectrum of audible sound. So, if a DAC is performing to redbook specs, it will sound just like every other DAC that performs at redbook specs.

The only way a DAC could sound *different* is if it has a deliberate rolloff at the top to make it sound "warmer", or if the implementation is so sloppy, audible levels of distortion are being introduced. The former is more likely in high end equipment that is intentionally being made to sound different, and the latter is more likely in extremely cheap equipment that isn't properly designed and manufactured. The vast majority of equipment in the middle all sounds the same.

 

[bigshot]

the musicality or the "emotions" if you will, is either "incorrect" or just plain "missing".
 
So I guess my question boils down to this. How, if this is indeed real, do you tune a solid-state device?

Musicality and emotion are functions of the human beings making the music, not the equipment reproducing it. Flowery language like this describes nothing when it comes to electronics. Tuning is calibration. Electronics are calibrated and designed toperform to specifications. The level of variation is small enough to be inaudible.

Headphones and speakers are a totally different animal, because they involve mechanical parts that are impossible to manufacture to such exacting standards.