[Shike]

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Originally Posted by JaZZ /img/forum/go_quote.gif You may have noticed the part about «Stereoplay»'s research. They have found out how minimal harmonic distortion defines the resulting characteristic. It's not that amps really measure the same, let alone when measured with a complex dynamic load.

Your wording isn't exactly clear here, please clarify.


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What does portable or desktop design have to do with measuring data? I think you believe in identical sound with identical measurements. The wire with gain scenario.

Portable amps usually don't have the same specs, like loads they're able to support without clipping.

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(Portable) Micro Amp: THD at 1 V output: <0.002, frequency response: 10–50k, ±0.3 dB (Portable) Desktop Amp: THD at 1 V output: <0.002, frequency response: 10–50k, ±0.3 dB Ultra Desktop Amp: THD at 1 V output: <0.002, frequency response: 10–50k, ±0.3 dB So why should you spend more than $349!

Those aren't entire specs which Headroom don't advertise. Still, I'm happy with $200 amps like the X-Head that measure extremely well.

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Euphonic distortion is the main argument against tubes. I thought you were addressing that when speaking of the inherent inaccuracy of tube amps. I don't consider output transformers a decisive weakness. So if that's your only argument... From your point of view you should look at the signal accuracy, not the design. Anyway, one point I agree with you is that tube amps aren't ideal for driving woofers.

My point is aimed at distortion and the trasnformers impact.

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It's a disadvantage. I never said the opposite. I wouldn't recommend OTL designs with speakers. With high-impedance headphones they usually harmonize well.

Yes you have, you've been endorsing anti-negative feedback designs.

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As mentioned, I have never measured amps myself, but the «Stereoplay» measurements speak a clear language: Negative feedback is evil. Maybe in moderation it is tolerable. But that's not exactly the point. The point is that amps do sound different beyond the classic measurement data.

Plenty of companies that make high-end gear would say Stereoplay is full of it. Furthermore, I would consider damping factor a matter of classical measurement data since if I remember right it's been around since the 60's. It's established and well documented.

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You're right (not with your assumption about my knowledge, though) – it was just a typo. I meant excessively high oputput impedance.

Fool me one shame on you, fool me twice shame on me . . . you've either been confusing them a lot or making lots of typos.

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Again: I don't listen at the upper end of amps' power capacity, so their clipping characteristic is relatively uninteresting.

I was just explaining why digital chips can sound like certain tube designs.

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So are you saying that you are a liar

Wait, how did I say I was a liar?

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because so many things I've stated are definitely wrong in your book (which you have let me know clearly)?

I believe you're more mistaken than anything else . . . it's certain questionable companies I'd call dishonest or liars.

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No, that's not true (and note that I don't call you a liar). I have fallen for the placebo effect many times, but have recovered very well.

Examples? Also define recovered.

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[/i]I don't recall such a statement from a cable-sound proponent – most admit to have experienced placebo effects. It's more like: If a sonic effect is consistent and reliable, it's not placebo.

We can't tell if the effect is consistent because many refuse partaking in a cited DBT.


EDIT:

Either way I'm stepping out of this argument. It's just going to do another circle again.

 

[JaZZ]

Quote:

Originally Posted by Shike /img/forum/go_quote.gif Quote: You may have noticed the part about «Stereoplay»'s research. They have found out how minimal harmonic distortion defines the resulting characteristic. It's not that amps really measure the same, let alone when measured with a complex dynamic load. Your wording isn't exactly clear here, please clarify.

I'll clarify my statement for you. «Stereoplay» has found a «formula» for passably predicting the sonic characteristic of an amplifier by means of the harmonic-distortion spectra. For a natural, organic sound a continuous, smooth decrease of higher harmonics is essential. Additionally the single harmonics should increase smoothly with increasing power. No amp is perfect in this discipline, but some are clearly better than others. And we're talking of values in the range of >0.005% THD. So an important insight is that minimal harmonic distortion has a decisive impact on the sound, and different amps measure and sound different, although classic measurement procedures don't reveal the differences (as relevant for the sound).


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Portable amps usually don't have the same specs, like loads they're able to support without clipping.

You care too much for extremes. HeadRoom's portable versions of their Desktop amps obviously use the same designs. The only imaginable difference is in the power capactity. Anyway, for $50 more you can have the desktop version with built-in power supply if it's important to you. Still their cheapest desktop amp measures the same as their most expensive one. I advise you to launch a protest about such selling politics.


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Those aren't entire specs which Headroom don't advertise. Still, I'm happy with $200 amps like the X-Head that measure extremely well.

There we have it!

So why have you felt insulted by my entry-level amp proposal?



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My point is aimed at distortion and the transformers impact.

...which translates to which measuring specs?


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Yes you have, you've been endorsing anti-negative feedback designs.

With good reason (see «Stereoplay»'s research!). Whereas you support distortion-prone negative feedback. Note: Renouncing negative feedback doesn't necessarily mean excessive output impedances.

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Plenty of companies that make high-end gear would say Stereoplay is full of it.

I have to wonder about your respect for those rip-off companies! In any event, their judgement doesn't change the facts and «Stereoplay's» measuring results. Why do you want them to be incorrect?


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Fool me one shame on you, fool me twice shame on me . . . you've either been confusing them a lot or making lots of typos.

I don't think that's the case. However, I think my «typos» are not the main purpose of this thread or our communication, are they?


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Wait, how did I say I was a liar?

I sense some strange stubbornness.

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I believe you're more mistaken than anything else . . . it's certain questionable companies I'd call dishonest or liars.

Such as HeadRoom and other high-end manufacturers (see above!)? Why is it that some of them care for designs renouncing negative feedback?


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We can't tell if the effect is consistent because many refuse partaking in a cited DBT.

We/you may not be able to tell, but I am. That's why I'm able to reject the placebo effect for my audio everyday life with my now components.
.

 

[Shike]

Quote:

Originally Posted by JaZZ /img/forum/go_quote.gif ...which translates to which measuring specs?

Distortion, bandwidth, SNR, among other things.

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With good reason (see «Stereoplay»'s research!). Whereas you support distortion-prone negative feedback. Note: Renouncing negative feedback doesn't necessarily mean excessive output impedances.

Usually it does.

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I have to wonder about your respect for those rip-off companies! In any event, their judgement doesn't change the facts and «Stereoplay's» measuring results. Why do you want them to be incorrect?

They aren't increasing the level of distortion, but spreading it across the band.

So you're saying Krell, Classe, Parasound, and other companies are now rip-offs?

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I don't think that's the case. However, I think my «typos» are not the main purpose of this thread or our communication, are they?

Typos -- sure.

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I sense some strange stubbornness. :regular_smile:

If you're accusing me of lying you better get straight to it.

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Such as HeadRoom and other high-end manufacturers (see above!)? Why is it that some of them care for designs renouncing negative feedback?

Headroom renounces negative feedback? Care to back that up with a source?

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We/you may not be able to tell, but I am. That's why I'm able to reject the placebo effect for my audio everyday life with my now components.

So you just said you're immune to placebo with your current components, including cables, without any form of DBT.

There you go people, because JaZZ says he's immune we must believe his findings without material evidence.

BTW, since you're so infatuated with that stereoplay article you wouldn't have a problem linking it here would you so we may all examine their measurements?


EDIT:

No matter how many times I step out I get drug back in

 

[nealric]

I was kind of hoping this thread would be more of a survey then a flame war about cables.

 

[JaZZ]

Quote:

Originally Posted by Shike /img/forum/go_quote.gif Distortion, bandwidth, SNR, among other things.

Sure. How much distortion does an output transformer add to the signal? Exactly enough to make it to the measured amount – which may admittedly be low enough to compete with solid-state amps nonetheless. How much bandwidth does it cut off? Little enough to make for a linear response 20 Hz to 20 kHz (less than -0.2 dB) and -3 dB at 100 kHz (just a random example from said «Stereoplay» issue – the T.A.C. K35). There are a few solid-state designs which purposely limit the response to much less, still with good sonic results. How much SNR does a transformer sacrifice? Virtually nothing. So where's the great handicap? It's easily made up for in the form of a smooth and organic characteristic which favorably contrasts to a few hard and technical sounding solid-state amps trimmed to measure perfect (on a resistive load).


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Usually it does.

An audiophile design like that won't renounce the expense necessary for an appropriate damping factor. It may not be on the same level as an amp with heavy negative feedback, but who's going to pretend that an output impedance of <0.2 ohm offers any sonic advantage – in view of the cables and possible crossover networks. And first of all among the tested amps (in the «Stereoplay» test) those with low negative feedback (not specified how much) have shown clear sonic advantages over those with high negative feedback – beside their metrological superiority under these real-world measuring conditions.


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They aren't increasing the level of distortion, but spreading it across the band.

What are you talking about?


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So you're saying Krell, Classé, Parasound, and other companies are now rip-offs?

Hehe... not me! I've put myself in your position, with your perfect $200 amp. Don't you think asking any more without any sonic benefit is a rip-off?

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If you're accusing me of lying you better get straight to it.

You don't get it!

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Headroom renounces negative feedback?

Not that I know of.


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So you just said you're immune to placebo with your current components, including cables, without any form of DBT.

I'm not saying I'm immune, but I don't have any opportunity to fall for placebo effects.


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There you go people, because JaZZ says he's immune we must believe his findings without material evidence.

No comment. You can go on and believe what you want like before.


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BTW, since you're so infatuated with that stereoplay article you wouldn't have a problem linking it here would you so we may all examine their measurements?

It's in fact two articles: one about the distortion spectra and one about the distortion as a result of negative feedback. They're available online, but you have to be a subscriber – and they're German.

In case you're extremely interested and eager to learn something new, get yourself «Stereoplay» issue 1/2010 on eBay.


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No matter how many times I step out I get drug back in

But it's the last time now, right?!

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Originally Posted by nealric /img/forum/go_quote.gif I was kind of hoping this thread would be more of a survey then a flame war about cables.

It's no longer about cables.

.

 

[bcwang]

For me, this list would have been quite different years ago before I had more experience with actually trying things out vs just speculating that "there is no way that could make any difference". But as of now, these are the things that have made an audible difference for me.

the obvious ones:
-headphone
-source (some still think all cd players sound the same, maybe this belongs in the next category)

the ones some may believe:
-analog interconnects

the ones few would believe:
-usb cable
-the specific usb port picked on the computer
-foobar vs winamp playing flac files - both through asio

the ones I haven't had an opportunity to test but would like to:
-power cords
-digital cable (easy for me to believe as I've already personally heard usb cables make a difference)
-power conditioning

 

[donunus]

Jazz and Shike,
I love your arguments. I wished more headfi battles were this detailed even though the people are personally starting to attack each other already.

 

[Shike]

Quote:

Originally Posted by JaZZ /img/forum/go_quote.gif Sure. How much distortion does an output transformer add to the signal? Exactly enough to make it to the measured amount – which may admittedly be low enough to compete with solid-state amps nonetheless. How much bandwidth does it cut off? Little enough to make for a linear response 20 Hz to 20 kHz (less than -0.2 dB) and -3 dB at 100 kHz (just a random example from said «Stereoplay» issue – the T.A.C. K35). There are a few solid-state designs which purposely limit the response to much less, still with good sonic results. How much SNR does a transformer sacrifice? Virtually nothing. So where's the great handicap? It's easily made up for in the form of a smooth and organic characteristic which favorably contrasts to a few hard and technical sounding solid-state amps trimmed to measure perfect (on a resistive load).

Depends on the quality of transformers used. There are some very good ones and some very bad ones.

As for "smooth and organic", depends on the amp and taste.

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An audiophile design like that won't renounce the expense necessary for an appropriate damping factor. It may not be on the same level as an amp with heavy negative feedback, but who's going to pretend that an output impedance of <0.2 ohm offers any sonic advantage – in view of the cables and possible crossover networks.

Depends, damping factor is more important for speakers than headphones.

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And first of all among the tested amps (in the «Stereoplay» test) those with low negative feedback (not specified how much) have shown clear sonic advantages over those with high negative feedback – beside their metrological superiority under these real-world measuring conditions.

Clear sonic advantages . . . how? They're inaudible by all known science.

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What are you talking about?

The total distortion actually decreases, but more harmonics start showing in the higher bands. The level should still be lower than audibility.

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Hehe... not me! I've put myself in your position, with your perfect $200 amp. Don't you think asking any more without any sonic benefit is a rip-off?

I do . . . personally I believe the gainclone is more than sufficient for many speaker setups.

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Not that I know of.

Then how was mentioning them relevant?

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I'm not saying I'm immune, but I don't have any opportunity to fall for placebo effects.

No opportunity? How do you figure?

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It's in fact two articles: one about the distortion spectra and one about the distortion as a result of negative feedback. They're available online, but you have to be a subscriber – and they're German. In case you're extremely interested and eager to learn something new, get yourself «Stereoplay» issue 1/2010 on eBay.

Can you post the graph or measurements for us at least?

 

[JaZZ]

Quote:

Originally Posted by Shike /img/forum/go_quote.gif Depends on the quality of transformers used. There are some very good ones and some very bad ones. As for "smooth and organic", depends on the amp and taste. Depends, damping factor is more important for speakers than headphones. ...personally I believe the gainclone is more than sufficient for many speaker setups.

Really?

No absolutisms anymore?


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Clear sonic advantages . . . how? They're inaudible by all known science.

...except for this one...


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The total distortion actually decreases, but more harmonics start showing in the higher bands. The level should still be lower than audibility.

I have no idea what this relates to.


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Can you post the graph or measurements for us at least?

I'm no subscriber myself. Moreover, there are several graphs and accompanying text which is essential to understand the context. Also, posting the full articles would violate copyright laws. So: sorry! Just another hint: The main article about the harmfulness of negative feedback is in issue 5/09 (the one in issue 1/10 is just a brief revival). A short abstract:
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Renouncing negative feedback in the output stage leads to higher «prospectus» distortions on ohmic resistances. In turn over-all negative feedback creates – in co-operation with the speakers – temporally flawed correction signals.

.

 

[Shike]

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Originally Posted by JaZZ /img/forum/go_quote.gif Really? No absolutisms anymore?

What are you talking about? I've stated amps can sound different if one is substantially deficient compared to another one -- assuming the goal is a wire with gain.

Of course an amp that's built wrong can sound bad. Otherwise there wouldn't be "good" amps.

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...except for this one...

Yes, because established scientific facts should be ignored

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I have no idea what this relates to.

Negative feedback. The total level decreases, but it may extend into higher frequencies compared to a design that doesn't have negative feedback. That's the only negative I've heard on negative feedback so to speak, it becomes more "complex" according to Nelson Pass.

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I'm no subscriber myself.

Then where are you getting this information from?

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Moreover, there are several graphs and accompanying text which is essential to understand the context. Also, posting the full articles would violate copyright laws. So: sorry! Just another hint: The main article about the harmfulness of negative feedback is in issue 5/09 (the one in issue 1/10 is just a brief revival). A short abstract:

So in other words you cite an article that no one has access to but you, so we're only allowed your interpretation of the article?

Judging by the abstract though is they're saying the damping factor isn't correcting the signal properly. Of course without knowing methodology or how they're measuring it this source of yours is useless to anyone but you. I'm guessing it's also not peer reviewed.

 

[JaZZ]

Quote:

Originally Posted by Shike /img/forum/go_quote.gif What are you talking about? I've stated amps can sound different if one is substantially deficient compared to another one -- assuming the goal is a wire with gain.

I've never heard a developer claim that his amp be a wire with gain.


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Of course an amp that's built wrong can sound bad. Otherwise there wouldn't be "good" amps.

«Good» and «bad» are in the ears of the beholder. I own (and have owned/auditioned) many different amps, most of them sounded good or very good to me. Some of them are better than others, some are equal and nevertheless different. Different they're all.


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Yes, because established scientific facts should be ignored

(See above!) How about this: «All properly designed amps sound the same, and that's a scientific truth set in stone.»


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Negative feedback. The total level decreases, but it may extend into higher frequencies compared to a design that doesn't have negative feedback. That's the only negative I've heard on negative feedback so to speak, it becomes more "complex" according to Nelson Pass.

That's a hint toward the «Stereoplay» discovery, but I guess it's still related to static measurements on resistive loads.


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Then where are you getting this information from?

From the magazine (in paper).


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So in other words you cite an article that no one has access to but you, so we're only allowed your interpretation of the article?

Not exactly. Every German speaking European has access. Print run is 53,400.


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Judging by the abstract though is they're saying the damping factor isn't correcting the signal properly. Of course without knowing methodology or how they're measuring it this source of yours is useless to anyone but you. I'm guessing it's also not peer reviewed.

After all most of the editors are EEs.

I for one am not, so I can't judge if their methodology is adequate and the conclusion is correct. But I'm very interested in every attempt to bring sonic perception and measuring data into accordance. Negative feedback is under suspicion by many audiophiles and electronics developers, and harmonic-distortion spectra are still one of the main candidates for sonic differences. «Stereoplay»'s approach has a high plausibility to me, particularly the one about decreasing/increasing harmonics (which BTW they're not really the first with).

My speaker amp is a Metaxas Solitaire with a negative feedback of only 11 dB and pretended to have low harmonic distortion above 2rd order harmonics. It is by far the most pure, clear, clean and nevertheless organic sounding speaker amp I've ever heard (and has become even better after a small modification making fo even higher bandwidth). And this even in sighted tests!

.

 

[leeperry]

only page 7? c'mon

so "an amp that's built wrong can sound bad", now we're getting somewhere!
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Originally Posted by bcwang /img/forum/go_quote.gif the ones some may believe: -analog interconnects

yep, to some ppl's experience(including mine), some interconnects can change the sound more than an opamp rolling ever would..

 

[Shike]

Quote:

Originally Posted by JaZZ /img/forum/go_quote.gif I've never heard a developer claim that his amp be a wire with gain.

No, but we can get close enough to the standard that the differences are inaudible.

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«Good» and «bad» are in the ears of the beholder.

While you're right I have to question who would want an amp with 10dB SNR, 10+% THD, etc, etc.

At some point even the subjectivist of subjectivists has to cringe.

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I own (and have owned/auditioned) many different amps, most of them sounded good or very good to me. Some of them are better than others, some are equal and nevertheless different. Different they're all.

If they all are oriented towards being a wire with gain, but you're hearing a difference, it's either placebo or one is deficient.

Of course I would ask for a DBT, but knowing my luck they'd all be tubes with different amounts of distortion and bandwidth.

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(See above!) How about this: «All properly designed amps sound the same, and that's a scientific truth set in stone.»

Sounds about right -- at least if their goal is accurate reproduction.

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I for one am not, so I can't judge if their methodology is adequate and the conclusion is correct. But I'm very interested in every attempt to bring sonic perception and measuring data into accordance. Negative feedback is under suspicion by many audiophiles and electronics developers, and harmonic-distortion spectra are still one of the main candidates for sonic differences. «Stereoplay»'s approach has a high plausibility to me, particularly the one about decreasing/increasing harmonics (which BTW they're not really the first with).

So in other words your evidence is minimal at best and is "plausible" to you.

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My speaker amp is a Metaxas Solitaire with a negative feedback of only 11 dB and pretended to have low harmonic distortion above 2rd order harmonics. It is by far the most pure, clear, clean and nevertheless organic sounding speaker amp I've ever heard (and has become even better after a small modification making fo even higher bandwidth). And this even in sighted tests!

Now if only we could quantify those terms and do a DBT.


EDIT:

There's no point in continuing this, it's obvious we're both cemented in our standpoints.

 

[JaZZ]

Quote:

Originally Posted by Shike /img/forum/go_quote.gif No, but we can get close enough to the standard that the differences are inaudible.

That would exactly be the wire-with-gain scenario. Yet no developer (that I know of) pretends to have achieved this ideal (just some pretenders among the consumers).


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While you're right I have to question who would want an amp with 10dB SNR, 10+% THD, etc, etc. At some point even the subjectivist of subjectivists has to cringe.

You really like extremes!

Show me some corresponding examples! I wouldn't buy such an amp, nobody would buy it, even without knowledge of the measuring data.


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If they all are oriented towards being a wire with gain, but you're hearing a difference, it's either placebo or one is deficient.

I'd say all of them are more or less deficient, since none approaches the wire-with-gain ideal enough to produce zero audible deviation from the input signal. According to their specs they should sound identical in your book, though, so the placebo scenario will have to do it for you.


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Of course I would ask for a DBT, but knowing my luck they'd all be tubes.

Tube amps were in the minority, but you don't have to ask for DBT in my case anyway. I don't unnecessarily complicate my life, and DBTs with headphone amps are complicated. Do you seriously expect electronics developers to constantly absolve DBTs during the development process? BTW, I would expect you to be heavily irritated by their sales politics with many overpriced rip-off products without any sonic benefit compared to the cheap offers in their line-ups.


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So in other words your evidence is minimal at best and is "plausible" to you.

Yes, that's it. I don't know what you have expected. But if you're really interested, there would be a way to get yourself access to these articles. Of course you can also reject these ideas beforehand if they go against your convictions (see above).


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Now if only we could quantify those terms and do a DBT.

DBTs with power amps are almost impossible to do without a gigantic effort, which I don't consider justifiable in view of the clear results obtainable the classic way.


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There's no point in continuing this, it's obvious we're both cemented in our standpoints.

That doesn't necessarily apply to me. I'm open-minded. That's why I'm interested in new approaches.
.

 

[aimlink]

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Originally Posted by JaZZ /img/forum/go_quote.gif You care too much for extremes. HeadRoom's portable versions of their Desktop amps obviously use the same designs. The only imaginable difference is in the power capactity. Anyway, for $50 more you can have the desktop version with built-in power supply if it's important to you. Still their cheapest desktop amp measures the same as their most expensive one. I advise you to launch a protest about such selling politics.

None of HeadRoom's desktop offerings pack built in power supplies.

Just to clarify that tiny point.

Additionally, what's all this about lying. Lying implies willful deceit. I see none of that happening on this thread or anyone accusing anyone else of it. It's not only sound differences that are real or imagined.