[ultrabike]

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One way to protect ones Ideas is to not publish the real reason for the benefit but to bamboozal people with ideas that have nothing to do with the real reason for the sonic difference.

 
Yes, I very much agree with this statement.
It appears to me that most of what you read from manufacturers is propaganda used to bamboozle the average Joe or the typical non technical audiophile.
I believe that companies such as Pass Labs, Arcam and Bryston have done significant research to reduce the amount of EMI and RFI created by and affecting their equipment.
But if you read Arcam's PR they use voodoo terms like "Mask Of Silence" and "Stealth Mat" to describe EMI and RFI reduction techniques.
The Pass Labs redesign from the X-150 to X-150.5 power amp (as another example) had a similar rationale.

 
Exactly. I think I get what germanium was talking about better, and it is a very valid point. Sometimes they give you a hint, but it's all clear as mud. It reminds me of some interesting post regarding some white papers:
 
http://www.head-fi.org/t/619882/cambridge-audio-upsampling-claims#post_8571636. (Cambridge Audio)
http://www.head-fi.org/t/615001/is-high-end-audio-a-scam/855#post_8558483 (Naim Audio)
 
I had to read and re-read those white papers to sort of try to make sense out of them. I could only guess as to what these white papers are talking about. I can see there is a good deal of marketing bamboozal factor there. Cosmological Holography material that took a lot of inspiration. Not that the products are bad, magical, or flat out wrong. In fact, from the big words and diagrams, one could speculate that some way cool tech is going on.

 

[qusp]

perfect simulation requires perfect models, not even manufacturers provide perfect models of single components, let alone the complex parasitic effects of collections of them on a PCB in a real environment. we are getting there, but to believe we are there is folly.
 
objectively, build and measure is still king and that takes serious time and investment. in this process listening should not be ignored and I think to reduce even that to an objective exercise (DBT) every time is to completely miss the point. do you need to DBT your music collection to know you enjoy it?

 

[Chris J]

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The red portion is a good point that I think deserves re-highlighting.  I mean, seriously, what's the design process behind improving something you can't demonstrate?  If not, I want to hear about it.  (Next, we'll have people saying that it's trade secrets...)
 
On a side note, say what you want about audio benchmarks correlating to sound quality and listening experience, but would it kill people to at least provide honest output power specs into different loads?

 
Trade secrets: rather hard to make a claim of "Trade secrets" when it comes to something like the design of a vacuum tube headphone amp, isn't it?
But you raise a good question:  "what is the design process behind improving something you can't demonstrate?"
OTOH, it sounds a bit intangible, but I would expect any audio designer to listen to the product somewhere in the design phase. But if the product "doesn't sound right" you have to objectively start looking somewhere for the source of this. Hopefully it will be some parameter that the audio designer had not thought relevant or had neglected earlier in the design phase.  Voodoo incantations will not fix it.
 
As for honest output power specs..............full disclosure would probably be too much for the average layman to interpret properly.  How does this amp reactive to complex impedance loads? High phase angles?  Still, there must be a middle ground somewhere.  Some of the output specs I have seen are laughable in their brevity.
 
 
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I don't think this addresses the original question that was being asked.
 
Reducing EMI, or some other property of the known universe, is one thing.  Even if it's not readily apparent which steps should be taken to reduce emissions, reduce susceptibility, you can iterate, run through some math, redo the simulation, redesign, retest individual components, and importantly: re-evaluate.  At the end (or even at points in the middle), you can tell whether or not you've made an improvement.
 
How do you improve something that you can't measure (whether by bench equipment or ears)?  How do you evaluate whether or not your prototype was good at it, and how do you make a next prototype even better at it?  By guessing?

Thanks for the feedback, it was an attempt to answer your question.
It's a difficult question to answer.
Brand X amp has adequate slew rate, low distortion, low S/N, good impulse response, etc, etc, etc.
So what makes it sound "better" than brand Y amp?
I'm not sure I can properly answer that question.
The white papers a lot of audio manufacturer's publish are really not very illuminating, I think they only add to the confusion.
 
The EMI/RFI was only supposed to be an example of one set of parameters the designers may be trying to optimize without really telling the consumers what is really going on. 
Guessing ain't going to improve your prototype.
Controlled listening tests, perhaps?
 
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perfect simulation requires perfect models, not even manufacturers provide perfect models of single components, let alone the complex parasitic effects of collections of them on a PCB in a real environment. we are getting there, but to believe we are there is folly.
 
objectively, build and measure is still king and that takes serious time and investment. in this process listening should not be ignored and I think to reduce even that to an objective exercise (DBT) every time is to completely miss the point. do you need to DBT your music collection to know you enjoy it?

 
Very true, perfect simulation requires perfect models.
In high frequency design work (for example, switchmode power supply design or EMI/RFI reduction/suppression) all the complex parasitic effects become extremely important and extremely difficult to model/simulate.

 

[germanium]

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In terms of qualifications, for those who are new or simply do not know, I should probably state that my hobby is to measure headphones when I'm not listening to them. These measurements are assembled in one place on the Internet somewhere.
 
I neither consider myself a subjectivist or objectivist. I like measurements when available, and I am particularly interested in finding measurements which correlate with subjective phenomena. I like to think that while measurements don't explain everything, they can at least keep us honest.

Totaly agree.
 
Coming up with a set of measurements that confirm the difference I hear with different parts types so far has been unfruitfull at least with standard mesurements yet some of these differences are easily heard under the right conditions.
 
The right condition I refer to here is bleed capacitor in the negative feedback loop of the high gain amp. Here the differences are so easily heard that its not funny. Electrolytic=huge loss in audible terms, Metalized films=much lower loss, not easily heard compared to the no loss condition of  a strait piece of wire used in the same location.
 
It would be nice to come up with a measurement that would be able to correlate these losses I hear between these parts types with measurements but I haven't seen any yet that would do just that. Current mearements are too focused of the more gross types of distortion that have for the most part been eliminated with good design but sonic differences still remain under these conditions so obviously we need to come up with better measurements in order to get at the bottom of these highly audible phenomenom.

 

[Chris J]

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Totaly agree.
 
Coming up with a set of measurements that confirm the difference I hear with different parts types so far has been unfruitfull at least with standard mesurements yet some of these differences are easily heard under the right conditions.
 
The right condition I refer to here is bleed capacitor in the negative feedback loop of the high gain amp. Here the differences are so easily heard that its not funny. Electrolytic=huge loss in audible terms, Metalized films=much lower loss, not easily heard compared to the no loss condition of  a strait piece of wire used in the same location.
 
It would be nice to come up with a measurement that would be able to correlate these losses I hear between these parts types with measurements but I haven't seen any yet that would do just that. Current mearements are too focused of the more gross types of distortion that have for the most part been eliminated with good design but sonic differences still remain under these conditions so obviously we need to come up with better measurements in order to get at the bottom of these highly audible phenomenom.

 
You are probably aware of this, but I'll post anyway:
Compare the leakage current (or leakage resistance) of the elecrolytic vs. the metaized film.
Also dissipation factor and dielectric absorption sound like they are the relevant parameters here. 
Generally speaking, the metallzed film caps will have far superior dissipation factor and dielectric absorption relative to the electrolytics.
 
I guess the amp(s) you refer to are also using cheap electrolytics?

 

[Shike]

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It would be nice to come up with a measurement that would be able to correlate these losses I hear between these parts types with measurements but I haven't seen any yet that would do just that. Current mearements are too focused of the more gross types of distortion that have for the most part been eliminated with good design but sonic differences still remain under these conditions so obviously we need to come up with better measurements in order to get at the bottom of these highly audible phenomenom.

 
Which are still entirely up for debate >_>'

 

[LizardKing1]

Purrin out of curiosity, when you say that "measurements don't explain everything" do you mean as of right now, like we don't have the means to understand and measure certain occurrences yet but they are available for measurement, or that there are effects in audio which are actually beyond the scope of Science, like a Heisenberg Principle kind of thing, which regardless of technology cannot be measured.

 

[Currawong]

I've noticed that, for the most part, when people talk about measurements here, they talk about them in general terms and, much beyond mentioning figures connected with what is supposedly audible or not, there is little discussion about how they relate to our listening experience. The exception has mostly been the discussion of harmonic distortion.  
 
An interesting comment made to me by a manufacturer was that he was a strong "measurements first" idealist when he was younger, but as he grew more experienced he moved away from this. I think the problem is that some people want audio to be all absolute scientific truths, but don't understand that science, and thus audio product design, doesn't work that way. Nor is everything a scam from manufacturers that don't supply considerable measurements. 
 
On the other side of the coin, while our own experiences can be unreliable, that doesn't mean they are all the time. If we make an effort to be aware enough of ourselves and the contexts in which we experience things, we can eliminate quite a bit of the uncertainty. However, if we cannot trust your yourself not to be deceived by what you hear, how can we trust ourselves not to be deceived by what people write? We have to apply this caution beyond just listening, while not losing site of the fact that we're here to find ways to enjoy listening to music more.

 

[germanium]

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Which are still entirely up for debate >_>'

Under  the condition I just listed the effect is highly audible & is not up to debate for me.

 

[purrin]

LOL, I'm not into the Heisenberg Principle thing. That's stuff is more relevant at the subatomic stuff level.
 
My opinion comes from my own experience building speakers and measuring speaker drivers and headphones. I also rely a lot on listening, which of course is subject to many factors such as mood, placebo, reality distortion fields, kids interrupting me, etc. I also rely on blind tests whenever possible (less of the "instant ABX switcheroo", but more of "the put stuff inside black box, toggle random switch, see what happens for next few hours or days.")
 
One very serious concern I have is when people bring up measurements (or a set of measurements) which are very limited in scope, and then extrapolate them to mean something much more. A good example would be THD measurements at a few select frequencies, say 100Hz, 1kHz, and 10kHz) at the same level 0 or -1dbFS. Some people take these three measurements and come to all sorts of conclusions much larger than what is actually being measured. In this case, I would only have to say that music does not consist of three sine waves played independently of each other at 0 or -1dbFS (although it can be argued that simple steady state measurements often do translate to good performance with more complex steady state measurements.)
 
Let's take the case of the ODAC or O2: I actually do have a set of measurements (into simulated loads) which are consistent with What's-His-Face's own measurements. I also have more complex measurements (jitter, linearity, full spectrum 2-tone, multi-tone, distortion at -30db, -50db, etc.) Honestly, I have to say that the ODAC or O2 measures superbly with every thing I've thrown at it.
 
But yet at the same time, after rigorous comparison (involving other test subjects, not just me) the O2/ODAC just don't stack up to better sounding gear. Last night, we had an O2, Bryston BHA1, and Eddie Current S7 shootout, and I can say for certainty that the O2 that thoroughly trashed by the latter two amps. The O2 sounded flat, lacked low-level information extraction, and even sounded slightly muffled or veiled in comparison. And as for the "colored" tube amp, the EC S7; it actually sounded clearer, faster, more dynamic, more airy, and more capable of reproducing dynamic cues than the solid-state Bryston BHA1.
 
So what gives? I have no idea. Bottom line is that I think all effects in audio can be measured, but we just need to discover the right ways to measure them. Just remember that no one knew what the heck "treble ringing" was with headphones just a year ago until I started posting CSD waterfall plots. I dunno, may the entire CSD thing was reality distortion field thing that I set up to make people hear even slight amounts of it with the LCD2r1s.

 

[germanium]

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You are probably aware of this, but I'll post anyway:
Compare the leakage current (or leakage resistance) of the elecrolytic vs. the metaized film.
Also dissipation factor and dielectric absorption sound like they are the relevant parameters here. 
Generally speaking, the metallzed film caps will have far superior dissipation factor and dielectric absorption relative to the electrolytics.
 
I guess the amp(s) you refer to are also using cheap electrolytics?

I agree with these forms of tests reveal different forms of loss but everything I have read tries to explain why these are not a factor in audio so we need tests that prove how these parts indeed cause the losses they do & I have not seen any that would & may be difficult to come up with one as you would have to use a complex signal with both soft & loud portions combined to really reveal them & the equipment that can measure these losses in the complex signal which I have not seen any that could.
 
They were but I have not found any that can truly get rid of all the losses. Even the best electrolyics that are supposedly audio grade still have these losses to one degree or anouther.

 

[germanium]

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LOL, I'm not into the Heisenberg Principle thing. That's stuff is more relevant at the subatomic stuff level.
 
My opinion comes from my own experience building speakers and measuring speaker drivers and headphones. I also rely a lot on listening, which of course is subject to many factors such as mood, placebo, reality distortion fields, kids interrupting me, etc. I also rely on blind tests whenever possible (less of the "instant ABX switcheroo", but more of "the put stuff inside black box, toggle random switch, see what happens for next few hours or days.")
 
One very serious concern I have is when people bring up measurements (or a set of measurements) which are very limited in scope, and then extrapolate them to mean something much more. A good example would be THD measurements at a few select frequencies, say 100Hz, 1kHz, and 10kHz) at the same level 0 or -1dbFS. Some people take these three measurements and come to all sorts of conclusions much larger than what is actually being measured. In this case, I would only have to say that music does not consist of three sine waves played independently of each other at 0 or -1dbFS (although it can be argued that simple steady state measurements often do translate to good performance with more complex steady state measurements.)
 
Let's take the case of the ODAC or O2: I actually do have a set of measurements (into simulated loads) which are consistent with What's-His-Face's own measurements. I also have more complex measurements (jitter, linearity, full spectrum 2-tone, multi-tone, distortion at -30db, -50db, etc.) Honestly, I have to say that the ODAC or O2 measures superbly with every thing I've thrown at it.
 
But yet at the same time, after rigorous comparison (involving other test subjects, not just me) the O2/ODAC just don't stack up to better sounding gear. Last night, we had an O2, Bryston BHA1, and Eddie Current S7 shootout, and I can say for certainty that the O2 that thoroughly trashed by the latter two amps. The O2 sounded flat, lacked low-level information extraction, and even sounded slightly muffled or veiled in comparison. And as for the "colored" tube amp, the EC S7; it actually sounded clearer, faster, more dynamic, more airy, and more capable of reproducing dynamic cues than the solid-state Bryston BHA1.
 
So what gives? I have no idea. Bottom line is that I think all effects in audio can be measured, but we just need to discover the right ways to measure them. Just remember that no one knew what the heck "treble ringing" was with headphones just a year ago until I started posting CSD waterfall plots. I dunno, may the entire CSD thing was reality distortion field thing that I set up to make people hear even slight amounts of it with the LCD2r1s.

 
It appears that the eddie current may be pushpull AB1 or AB2 design. Either way a good portion of thier output would  be class A which in  pushpull tube amps takes the power supply out of the sound equation as when in class A mode of operation there is no current variation in the powersupply thus removing the power supply componants from having an effect on sound at least at lower sound levels.
Electrolytics cannot be used as coupling caps in tub amps generally as they have too much current leakage & that would alter the bias so film caps are almost always used here eliminating the loss vector at all levels. This would lead to the faster more open sound of the "colored" tube amp.
 
I bet if given the chance providing the O2 dac is large enough I could make it practically as good or better sounding than the bryston.

 

[Steve Eddy]

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I've noticed that, for the most part, when people talk about measurements here, they talk about them in general terms and, much beyond mentioning figures connected with what is supposedly audible or not, there is little discussion about how they relate to our listening experience.

 
It's rather difficult to meaningfully relate anything to our listening experience until an actual audible difference can be demonstrated in the first place. Otherwise, you're doing little more than chasing your own tail.
 
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An interesting comment made to me by a manufacturer was that he was a strong "measurements first" idealist when he was younger, but as he grew more experienced he moved away from this.

 
But what exactly does "experienced" mean? Just because someone may have been doing something for a long period of time doesn't necessarily mean they end up with any greater insight or meaningful knowledge. The person with the most experience is no less human than the person with the least experience and therefore no less susceptible to those human weaknesses that we may all be affected by. Sometimes, "experience" can actually reinforce those weaknesses leading to erroneous conclusions.
 
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On the other side of the coin, while our own experiences can be unreliable, that doesn't mean they are all the time

 
No, it doesn't. But it's precisely because they can be unreliable that that ambiguity must be adequately controlled for before we can come to any meaningful conclusions. And until they are adequately controlled for, it's all just a bunch of noise and we do not progress in our understanding.
 
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If we make an effort to be aware enough of ourselves and the contexts in which we experience things, we can eliminate quite a bit of the uncertainty.

 
That smacks a bit of self-delusion. Given that so much of our subjective perception comes from our subconscious, how can we hope to be aware of that which by definition we are not aware of?
 
What we need to make an effort to be aware of is that we're not aware of much which goes on inside our brains. Our consciousness is just a rather thin layer at the very top. And that our subjective perceptions are not the unerring reflections of the objective reality that we'd all like to think that they are. That's what keeps us from going from science to religion.
 
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However, if we cannot trust your yourself not to be deceived by what you hear, how can we trust ourselves not to be deceived by what people write?

 
Of course you can't. Which is why science doesn't get by based just on peoples' assertions. Those assertions have to be supported by credible, objective evidence.
 
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We have to apply this caution beyond just listening, while not losing site of the fact that we're here to find ways to enjoy listening to music more.

 
I thought the Sound Science Forum was here to separate the objective side of things from the subjective side of things?
 
Just as some other forums here are DBT-Free Zones, the Sound Science Forum should be a Subjective-Free Zone.
 
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[purrin]

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Just as some other forums here are DBT-Free Zones, the Sound Science Forum should be a Subjective-Free Zone.

 
I thought the Sound Science forum was just a place for people to argue pointlessly about theory of measurements, DBT, etc., rather than people actually producing measurements, data, or studies which are relevant to the hobby.

 

[Steve Eddy]

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I thought the Sound Science forum was just a place for people to argue pointlessly about theory of measurements, DBT, etc., rather than people actually producing measurements, data, or studies which are relevant to the hobby.

 

 
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