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Topic: "Why tubes sound better" nonsense article (Read 15875 times) previous topic - next topic
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"Why tubes sound better" nonsense article

The article:
Ken Rockwell - Why Tubes Sound Better

Claims:
Quote
Tube amplifiers have much more distortion than solid-state amplifiers, but most of it is second-order, which is quite musical. That's why it's called "harmonic" distortion.

They have much more distortion, yes, but the rest is nonsense.
"Harmonic" distortion is distortion that produces overtones with integer multiples of the original frequency. So for a 1 kHz tone the harmonics would be: 2 kHz, 3 kHz, 4 kHz, 5 kHz ...
Btw, even order (2, 4, 6 ..) distortion means asymmetric distortion.

As soon as you feed anything else than a single, pure tone into this distortion generator, the harmonic distortion will turn into nasty intermodulation distortion.
Even if the amp just produced a 2nd harmonic (which tube amps don't - they produce loads of higher harmonics as well), then a 100 Hz + 1 kHz tone would produce intermodulation products at 900 Hz and 1100 Hz at quite high levels.

That's not "musical". In fact, calling the distortion products of a pure tone measurement as "musical" is quite ironic.



Quote
Not only is tube amplifier distortion harmonious, it increases as things get louder - exactly as they do in a musical performance. As instruments play louder, or as you hit a percussion instrument or piano key more strongly, they generate more harmonic content.

So, we already got the distortion from the instruments on the recording. Now you want to add even more distortion? Why?
And why is the distortion of loudspeakers completely ignored here? They distort like crazy when you push them hard.


Quote
By comparison, here's how a typical solid-state amplifier, in this case a Crown D-75, lowers its distortion with level, and then suddenly clips like crazy

Wow, a comparison of a ~40W power amp with a tube headphone amp that surpasses 1% THD at below 0.06W.
And Ken makes it sound like you want to run into clipping and therefore the rapid rise in distortion in a solid-state amp is bad. What? No..


Quote
Just like our ears, musical instruments and just about everything else natural, tube amplifiers have the least distortion at the lowest levels. This is why a tube amplifier can sound great played softly, while with transistor amplifiers people are usually needing to turn it up to have it sound best.

No and wtf? Where is the logic in this statement?


Quote
Tube amplifiers overload gradually. Add more input and they distort more, but there is no precise level above or below which they suddenly start to clip.
[...]
When a solid state amplifier clips, there is a sharp edge where it looks like someone simply took a pair of scissors to the tips of the waveforms. The sharp edges of solid state amplifier's waveforms at clipping give rise to insane levels of very high order ultrasonic harmonics, which are what blow out tweeters.

Sure, but when you need 10% distortion at 10W to hear that your super-duper tube amp is at its last breath, then you probably should not purchase any amplifiers. (At the end of the article there's even a recommendation for a 3W tube amp for "If you really want to hear the "tube sound"")
In other words if you randomly buy inadequate amplifiers, which you then hopelessly overdrive and destroy your speakers with then it's your own fault.

This is a bit like saying I'd rather have a blunt knife to cut my food, because one slip with a sharp knife and I will be dead.

I'm positive that a cheaper solid-state amp would easily output twice or even magnitudes more power than such a badly distorting tube amp - before any significant rise in distortion.


<claims about capacitors>
I'll let amplifier designers comment.


Quote
While feedback itself isn't really bad, what is bad is sloppy basic amplifier linearity that needs a lot of negative feedback to test well.

You could improve an amplifier by improving its basic linearity, but if it performs well then it performs well. Ken makes it sound like extra feedback is added just for tests, which of course is nonsense.
There is no such thing as too much feedback.™


Quote
It's easy to identify an amplifier that works with a lot of feedback to cover up its basic flaws: it has a distortion curve that rises with frequency and has foolishly low output source impedances (high damping factors), as most Crown amplifiers do

Or there is too little loop gain at high frequencies. Low output impedance is good.


Quote
Microphonics can lead to a warmer, fatter sound from this extra reverberation.

I guess you can spin everything clearly bad around ... and audiophiles will even buy it.


Quote
So why tubes today?

Simple: because they sound better, and today our recordings and speakers are good enough that we finally can appreciate the subtly magical things they do for our music.

Today everything else in the chain is so transparent that one added layer of "tube sound" is just about perfect.

No they don't.
Loudspeakers are far from being transparent.
And anyway, now that we've finally got a clean chain that you can buy for little money you need to go back to distortion generators?


Quote
In reality, tube amplifiers tend to have enough distortion that does make them sound different. Frequency responses vary, and output impedances certainly vary wildly from one kind of amplifier to the next which has a big impact on the sound.

That's a bad thing, right? Then why say that tubes therefore sound better?


Quote: >>If everything transistorized tries to claim it's as good as tubes, why not just go with tubes? It's funny how some people will pay $50,000 for a frou-frou solid-state amplifier just because it claims to sound "almost as good as tubes," instead of simply stepping up to a real tube amplifier. Geesh,<<
Geesh indeed. More spinning.
It's funny how some people will pay $$$ for <10W tube amps when there are much cheaper, much better, much more reliable, more powerful ... solid-state amps.


And finally there is a confusion of music vs. audio reproduction as art.
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #1 –
Quote from: xnor on
The article:
Ken Rockwell - Why Tubes Sound Better

Claims:
Quote
Tube amplifiers have much more distortion than solid-state amplifiers, but most of it is second-order, which is quite musical. That's why it's called "harmonic" distortion.

They have much more distortion, yes, but the rest is nonsense.
"Harmonic" distortion is distortion that produces overtones with integer multiples of the original frequency. So for a 1 kHz tone the harmonics would be: 2 kHz, 3 kHz, 4 kHz, 5 kHz ...
Btw, even order (2, 4, 6 ..) distortion means asymmetric distortion.


And we already have three fallacies.

The first fallacy is that tubes don't produce odd order distortion, which being exponential devices they do.

The second  fallacy is that they always produce second order distortion, which is in actuality cancelled out by push-pull operation.

The third  fallacy is that any order nonlinearity is euphonic. While a second order nonlinearity (already debunked but what the hey?) will produce second harmonic distortion which is at least harmonic, it also produces second order IM which is aharmonic or non-harmonic and makes the sound seem to be sour.

Quote
As soon as you feed anything else than a single, pure tone into this distortion generator, the harmonic distortion will turn into nasty intermodulation distortion.
Even if the amp just produced a 2nd harmonic (which tube amps don't - they produce loads of higher harmonics as well), then a 100 Hz + 1 kHz tone would produce intermodulation products at 900 Hz and 1100 Hz at quite high levels.

That's not "musical". In fact, calling the distortion products of a pure tone measurement as "musical" is quite ironic.


We agree about this but what are to facts to a spinner of tall tails?

Quote
Quote
Not only is tube amplifier distortion harmonious, it increases as things get louder - exactly as they do in a musical performance. As instruments play louder, or as you hit a percussion instrument or piano key more strongly, they generate more harmonic content.

So, we already got the distortion from the instruments on the recording. Now you want to add even more distortion? Why?
And why is the distortion of loudspeakers completely ignored here? They distort like crazy when you push them hard.

Quote
By comparison, here's how a typical solid-state amplifier, in this case a Crown D-75, lowers its distortion with level, and then suddenly clips like crazy



The apparent rise in distortion at low levels with SS amps is because the test is THD+D, and as the levels go down, the percentage of noise goes up.

Quote
Wow, a comparison of a ~40W power amp with a tube headphone amp that surpasses 1% THD at below 0.06W.
And Ken makes it sound like you want to run into clipping and therefore the rapid rise in distortion in a solid-state amp is bad. What? No..

Quote
Just like our ears, musical instruments and just about everything else natural, tube amplifiers have the least distortion at the lowest levels. This is why a tube amplifier can sound great played softly, while with transistor amplifiers people are usually needing to turn it up to have it sound best.

No and wtf? Where is the logic in this statement?

Quote
Tube amplifiers overload gradually. Add more input and they distort more, but there is no precise level above or below which they suddenly start to clip.
[...]
When a solid state amplifier clips, there is a sharp edge where it looks like someone simply took a pair of scissors to the tips of the waveforms. The sharp edges of solid state amplifier's waveforms at clipping give rise to insane levels of very high order ultrasonic harmonics, which are what blow out tweeters.



In fact tube amps roll over into clipping distortion when they clip quite rapidly because they have negative feedback, even if not loop feedback. The good ones have both.

"Why tubes sound better" nonsense article

Reply #2 –
Quote from: Arnold B. Krueger on
The first fallacy is that tubes don't produce odd order distortion, which being exponential devices they do.

The second  fallacy is that they always produce second order distortion, which is in actuality cancelled out by push-pull operation.

The third  fallacy is that any order nonlinearity is euphonic. While a second order nonlinearity (already debunked but what the hey?) will produce second harmonic distortion which is at least harmonic, it also produces second order IM which is aharmonic or non-harmonic and makes the sound seem to be sour.

Yes!
I've seen tube amps that produce a higher 3rd harmonic when clipping.

How the amp clips and distorts depends on the design. To say that all tube amps are the same is nonsense.


Quote from: Arnold B. Krueger on
The apparent rise in distortion at low levels with SS amps is because the test is THD+N, and as the levels go down, the percentage of noise goes up.

(I fixed that +N for you)
Ken is not even talking about that, but about a hard clipping point.
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #3 –
He writes this on his 'About' page:

Quote
This website is my way of giving back to our community. It is a work of fiction, entirely the product of my own imagination. This website is my personal opinion. To use words of Ansel Adams on page 193 of his autobiography, this site is my "aggressive personal opinion," and not a "logical presentation of fact."

"Why tubes sound better" nonsense article

Reply #4 –
This is the same guy who breathlessly described his BMW 540i and how it has "recirculating ball steering just like a Mercedes" and how "the common six cylinder 5-Series gets rack-and-pinion steering".

For those not into cars, rack and pinion steering is vastly superior for precision and steering feel compared to recirculating ball steering, which is ancient technology in comparision. The only reason it wasn't used on the otherwise very nice 540i of that particular vintage was for packaging reasons.

In other words, Ken Rockwell likes to wax lyrical for pages and pages about stuff he knows nothing about.

"Why tubes sound better" nonsense article

Reply #5 –
Well, there is a difference between posting your personal subjective opinion and posting wrong facts dressed as personal opinion.

"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #6 –
Apart from the article being BS on just about every point, there's an intriguing question raised about tube (valve) amp design. Why did the designers of such gear strive to make things have low distortion, if it sounds so good? I have an original copy of Mullard's audio circuit designs from the tube era. It's pretty obvious that they thought carefully about all aspects of these designs in order to minimise distortion, hum and noise. Why didn't they just leave the distortion performance sub-par? "Hey, this measures awful but the distortion just sounds gorgeous". Why the complexity of the ultra-linear, push-pull designs of later tube-years, they could have just stuck with the simpler, cheaper SET-output!

The answer is obvious, in anything with aspirations to hi-fi, distortion isn't a Good Thing and the designers of the day knew it applied then, just as much as it does today.

"Why tubes sound better" nonsense article

Reply #7 –
Let me quote:
Quote
tubes have more linear transfer functions

vs.
Quote
Tube amplifiers sound better because of the euphonic distortions


Or this:
Quote
If you really want to hear the "tube sound," get a TubeCube 7 (3 WPC, $180)

(this amp produces over 10% THD at 3W)
vs.
Quote
For the ultimate, get a classic McIntosh MC225 (25 WPC), MC240 (40 WPC) or MC275 (75 WPC), which are the best-designed tube amplifiers ever made. They excel for their stable designs (no bias adjustments or matched tubes ever needed) and have extremely low distortion due to their unique design.

(The MC275 produces 0.0x% THD up to ~80W into 4 ohms, then THD rapidly rises much like with one of those evil solid-state amps to >2% at 100W. The lower power versions should be identical in that respect just with lower clipping points.)


So what is it? Self-delusion?
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #8 –
In pictures. According to Ken this is good:


This is bad clipping behavior (hard to see because of the cursor at the end):


But he finally recommends this as "best-designed tube amplifiers ever made":




And regarding rising THD vs. frequency, this is bad because it rises with frequency:


But the "best-designed tube amplifiers ever made" measures like this:




And finally, this is was mostly 2nd order distortion does to just 2 sines waves (19+20 kHz):


(These images are from SP.)
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #9 –
Ken Rockwell - the mere mention of his name in the photography forums initiates gales of laughter.  Self-contradictory, full of bloated assertions not based on facts... yet this article encapsulates all of his absurdity in one place to marvel at.   

Well, I guess we have to have one wacko that everyone can agree on. 

For the photographers, incidentally, a good technical site (dare I say a reasonable counterpart to HA?) is Clarkvision - good, pretty balanced discussion of camera sensor data and astrophotography with some stunning images to ponder.  He does prefer the Canon system but is not dogmatic about it.

"Why tubes sound better" nonsense article

Reply #10 –
I'm not into photography. I stumbled upon his audio "reviews" some time ago because I was looking for some measurements.

Quote
Self-contradictory, full of bloated assertions not based on facts... yet this article encapsulates all of his absurdity in one place to marvel at.



So I guess it was not a complete waste of time bringing this article to other people's attention.
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #11 –
Yeah, the guy has been doing this for more than a decade. Dunning-Kruger, or genius troll. He's made a business out of it. Seems he's expanded outside of photography.

"Why tubes sound better" nonsense article

Reply #12 –
Quote from: Nichttaub on
For the photographers, incidentally, a good technical site (dare I say a reasonable counterpart to HA?) is Clarkvision - good, pretty balanced discussion of camera sensor data and astrophotography with some stunning images to ponder.  He does prefer the Canon system but is not dogmatic about it.

Love the old-fashioned hand-crafted html site, it's like tube-powered web/vinyl (What is not to like about canon? I have been using 7d for years now, and still love it (ok, it is not a pretty looking camera, but that's it).).
PANIC: CPU 1: Cache Error (unrecoverable - dcache data) Eframe = 0x90000000208cf3b8
NOTICE - cpu 0 didn't dump TLB, may be hung

"Why tubes sound better" nonsense article

Reply #13 –
A novice asks...

If one took this allegedly "euphonic" harmonic distortion to its ultimate conclusion,  wouldn't it turn every musical note into a chord? Wouldn't it be like playing one note on an organ that is supposed to sound like a flute, then pulling out all the stops, being blown against the wall by the sound and saying, "Awesome!" Except it wouldn't sound anything like a flute any longer

The most important audio cables are the ones in the brain

"Why tubes sound better" nonsense article

Reply #14 –
I'm afraid it will just sound distorted and louder. Think of clean vs distorted guitar sound.
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #15 –
Well, compression precedes clipping and we already know that some people have a preference for this effect when it comes to vinyl, so why not also tubes?

"Why tubes sound better" nonsense article

Reply #16 –
Quote from: Thad E Ginathom on
A novice asks...

If one took this allegedly "euphonic" harmonic distortion to its ultimate conclusion,  wouldn't it turn every musical note into a chord? Wouldn't it be like playing one note on an organ that is supposed to sound like a flute, then pulling out all the stops, being blown against the wall by the sound and saying, "Awesome!" Except it wouldn't sound anything like a flute any longer




Given that the problems of the aharmonic IM that is part and parcel of any kind of nonlinear distortion has been at least covered twice in the past two days. I guess the above post shows the slings and arrows of writing intelligent answers to newbies who seem to never read what you wrote.

Instead of condescending to admit that words like aharmonic and IM flew over their heads or that they didn't even bother to read the answers, they seem to just ask the same question over and over and over and over...

"Why tubes sound better" nonsense article

Reply #17 –
Whow cool down, he was just asking a question.

Certain distortion "profiles" certainly sound 'nicer' than others, but I would leave that choice to the artist (again, see guitar distortion).


Quote from: greynol on
Well, compression precedes clipping and we already know that some people have a preference for this effect when it comes to vinyl, so why not also tubes?

Soft clipping? What about DSP?
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #18 –
Quote from: greynol on
Well, compression precedes clipping and we already know that some people have a preference for this effect when it comes to vinyl, so why not also tubes?


I don't believe that there is any such general rule.

What is true is that a rise in distortion (albeit often subtle) precedes clipping.

Nonlinear distortion often causes a kind of compression but the resultant compression is usually subtle unless the distortion is very large.

One source of compression is due to heating of speaker voice coils, which is a mechanism that is largely free of inherent distortion. However the power levels sufficient to cause enough heating also usually causes distortion by independent means.

Compression with low distortion takes special circuitry but the compression due to distortion is usually relatively mild.

"Why tubes sound better" nonsense article

Reply #20 –
I guess I'm in the minority here in being mostly OK with Rockwell's site: I've grown accustomed to paying attention to the parts which seem like solid fact (test data) and am often at least entertained by the rest, even if it sometimes bears little relation to his data--guess I'm not as bothered by the disconnect.

Despite whatever line of reasoning he used to arrive at his recommendations, if I really wanted to buy a tube amplifier, those exact ones mentioned by KR (Mac 275, Elekit TU-8200) might be near the top of my list: Prior experience with Mac tube gear suggests to me that they're solid and conservative designs which perform reliably as tubes go. And Elekit really does make fine hobby kits.

Some of KR's rants are pretty good:
http://kenrockwell.com/business/take-your-vacation.htm

"Why tubes sound better" nonsense article

Reply #21 –
I wouldn't call it a disconnect. It's self-refuting and contradictory nonsense and factual statements that are wrong.
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #22 –
Quote
but sometimes the difference is so obvious that people's wives will comment that "wow, that sounds much better" when people use tubes at home


I wonder why wives are not part of the people

"Why tubes sound better" nonsense article

Reply #23 –
Hah. Reminds me of scripture. You shall not covet your neighbor's house, or wife, ... or anything else your neighbor owns. xD
"I hear it when I see it."

"Why tubes sound better" nonsense article

Reply #24 –
Quote from: greynol on
Well, compression precedes clipping and we already know that some people have a preference for this effect when it comes to vinyl, so why not also tubes?


Probably the all time champion example of compression due to more-or-less euphonic distortion was that achieved by magnetic tape being driven into saturation. Tape saturation had distortion that came on very slowly and was mixed with a low pass filter characteristic.  The amount of distortion without visible sharp edged clipping might extend up to 10% or more.