Thanks for that information! As I flaked out at the last minute last night and did not attend Hofer's presentation at the local AES, I missed the direct opportunity to query him about this and other matters. And having things in a table is sensible.
The MC approximation doesn't bother me too much for low inductance cartridges, which most of them are. The Ortofon high-output ones like the X5-MC have an astonishingly high 450mH L, considering the 80 ohm R. So both distortion at the input and the contribution of parallel noise will be missed with either generator impedance.
Of course the newest Ap instruments have a clever multitone capability, with some patents accompanying, but they were devised primarily to speed up measurements, not so much to provide insight into things.
Brad
According to Bruce Hofer, the newest Ap's with switchmode supplies, which he was quite leery of at the outset, are the first instruments they have made with no trace whatsoever of mains-related energy in their spectral outputs. He did allow that it took quite a while to find the right power supply vendor and the supplies are not cheap. As well, there is a very good common-mode choke in the system.
Brad
An overdriven amp in the context of guitars is an extension of the musical instrument and the performer, and I don't think has any pertinence as such to the tubes versus transistors debate for reproduction of music. And sure, no one will likely prefer hard clipping compared to the softer effect of most tube amps in either context --- so, don't drive things into clipping if you don't like clipping!
That is not to say that there are no other aspects of hollow-state electronics to recommend them. But I think the Argument-from-Clipping is vastly overemphasized.
It has everything to do with it.
Compare a "clean" channel amp if you prefer.
SS is known for sterile thin, clarity.
Tubes are nicer due to their particular harmonic content despite having generally higher THD.
Its the same debate, in a different context and forum.
So you cannot grade this class of amplifiers based on measurements alone.
If low THD were a practical measurement, the SS would be the better clean amp.
(Clean channel amp means the amplifier is reproducing the effects that are placed in front of it, rather then generating the effect.) In this context it is a reproducer.
One measures better, one sounds better.
Compare a "clean" channel amp if you prefer.
SS is known for sterile thin, clarity.
Tubes are nicer due to their particular harmonic content despite having generally higher THD.
Its the same debate, in a different context and forum.
So you cannot grade this class of amplifiers based on measurements alone.
If low THD were a practical measurement, the SS would be the better clean amp.
(Clean channel amp means the amplifier is reproducing the effects that are placed in front of it, rather then generating the effect.) In this context it is a reproducer.
One measures better, one sounds better.
It is subjective measurement, Thorsten.
But according to my measurements...
After you attacked me as if I support point of view that I don't support, I stopped discussions with you.
But may be you are right, it saves time on discussions with people because they don't talk to you.
Well as you wish. Again, I prefer no distortion to someone's euphonious distortion, no EQ to someone's euphonious EQ. And I prefer low output impedance to high unless the speaker designer used a specific high-Z amp for the development of the loudspeaker (and if we trust her to have done a good job).
But I am by no means anti-hollow state, and I think one can have its advantages without much of either linear or nonlinear distortion. And as Thorsten remarked a few hundred or more posts back, he liked a particular Audio Note amplifier in spite of its distortion, not because of it.
Measurements with steady-state sinusoids are almost worthless for detecting a host of problems. Tubes have many fine attributes including very low voltage/current modulation of interelectrode capacitances, and generally very-long-time-constant thermal effects --- and sand-state has the latter in spades, unless you methodically figure out ways around them --- and that's not as simple as throwing down a boatload of gain and then applying gobs of negative feedback to linearize it.
OMG what happened?? The thread is back on-topic again!
Brad
I would prefer no distortion as well.
Distortion in both devices is low enough these days that a THD number does not mean much. If amp A had %30 distortion and amp B had %5 distortion, then THD would be meaningful.
Both designs have attributes to them, they both have a "sound" independent of THD.
In the case of audio, I prefer nice colouration vs nasty, regardless of the devices being used.
Using THD is like choosing a car depending on how aerodynamic it is. It is only one parameter to consider. The actual performance of the vehicle depends on many aspects, like power to weight ratio, suspension, tire profile, economy etc.
You can have a car that is very aerodynamic in a wind-tunnel, but because the car has no engine, in reality it does not perform well at all.
As I stated before, you need an index of measurements to define sound quality, depending on the end-users requirements.
Distortion in both devices is low enough these days that a THD number does not mean much. If amp A had %30 distortion and amp B had %5 distortion, then THD would be meaningful.
Both designs have attributes to them, they both have a "sound" independent of THD.
In the case of audio, I prefer nice colouration vs nasty, regardless of the devices being used.
Using THD is like choosing a car depending on how aerodynamic it is. It is only one parameter to consider. The actual performance of the vehicle depends on many aspects, like power to weight ratio, suspension, tire profile, economy etc.
You can have a car that is very aerodynamic in a wind-tunnel, but because the car has no engine, in reality it does not perform well at all.
As I stated before, you need an index of measurements to define sound quality, depending on the end-users requirements.
And I don't think we disagree, at least not by very much.
THD is a useful measure of nonlinearity for steady-state symmetrical waveforms (one could extend to waveforms beyond sinusoids, although it might not be called THD anymore). If there is a whole lot of it something is clearly wrong and needs to be addressed. A lot of second-producing (quadratic) nonlinearity and one has d.c. shifts (that will be ultimately highpassed out of the overall system, but contribute to things that go bump in the night, and for some a sense of "being there", "greater realism", etc. --- see John Curl's remarks for example [Blowtorch Preamp thread] about hearing the Aphex stuff early on, and initially being favorably impressed until the Dead heard it and readily identified what it was). Also, quadratic nonlinearities will result in simple difference frequency energy, and this can be quite audible when it's in a region of high aural acuity (which makes me a bit impatient with the litany of "will be subjectively benign"). Note as well asymmetrical slewing or near-slewing will be a generator of even-order harmonic and difference-frequency IM distortion, something not well-understood in the early days of SID studies.
For other things like music, a host of effects arise that are poorly dealt-with via contemporary measurements, and are probably responsible for the "sound".
What may be emerging (into wider aknowledgement and understanding) is a sort of perceptual efficacy effect at work for certain preferences. It doesn't bother me (too much) that this may exist and nonetheless not be detectable in double-blind protocols.
I mentioned to Floyd Toole once that I was having to grapple with the idea that some people were just really much more sensitized to equipment attributes than others, perhaps even to what would currently be regarded as "woo-woo", "extrasensory", territory*. Rather than dismissing this notion out-of-hand, he said "But do we want those people to be the arbiters of audio quality?"
James Boyk used an example once, about perceptual judgments, in a LTE somewhere. He described a friend for whom all food was equally palatable, and who ate as cheaply as he could. He found absolutely no reason to pay more than the cheapest coffee-shop prices, and therefore did not.
Boyk agreed that there was no point to his doing otherwise. But then added, in the letter, that he would not be the person he'd consult for advice on restaurants.
Brad
*and not implying that such things are necessarily "unknowable" in principle. Clark's dictum, or at least the spirit of it here, perhaps: "Any sufficiently advanced technology is indistinguishable from magic."
THD is a useful measure of nonlinearity for steady-state symmetrical waveforms (one could extend to waveforms beyond sinusoids, although it might not be called THD anymore). If there is a whole lot of it something is clearly wrong and needs to be addressed. A lot of second-producing (quadratic) nonlinearity and one has d.c. shifts (that will be ultimately highpassed out of the overall system, but contribute to things that go bump in the night, and for some a sense of "being there", "greater realism", etc. --- see John Curl's remarks for example [Blowtorch Preamp thread] about hearing the Aphex stuff early on, and initially being favorably impressed until the Dead heard it and readily identified what it was). Also, quadratic nonlinearities will result in simple difference frequency energy, and this can be quite audible when it's in a region of high aural acuity (which makes me a bit impatient with the litany of "will be subjectively benign"). Note as well asymmetrical slewing or near-slewing will be a generator of even-order harmonic and difference-frequency IM distortion, something not well-understood in the early days of SID studies.
For other things like music, a host of effects arise that are poorly dealt-with via contemporary measurements, and are probably responsible for the "sound".
What may be emerging (into wider aknowledgement and understanding) is a sort of perceptual efficacy effect at work for certain preferences. It doesn't bother me (too much) that this may exist and nonetheless not be detectable in double-blind protocols.
I mentioned to Floyd Toole once that I was having to grapple with the idea that some people were just really much more sensitized to equipment attributes than others, perhaps even to what would currently be regarded as "woo-woo", "extrasensory", territory*. Rather than dismissing this notion out-of-hand, he said "But do we want those people to be the arbiters of audio quality?"
James Boyk used an example once, about perceptual judgments, in a LTE somewhere. He described a friend for whom all food was equally palatable, and who ate as cheaply as he could. He found absolutely no reason to pay more than the cheapest coffee-shop prices, and therefore did not.
Boyk agreed that there was no point to his doing otherwise. But then added, in the letter, that he would not be the person he'd consult for advice on restaurants.
Brad
*and not implying that such things are necessarily "unknowable" in principle. Clark's dictum, or at least the spirit of it here, perhaps: "Any sufficiently advanced technology is indistinguishable from magic."
Hofer is one of the all-time greats IMO. Cal Perkins practically worships him, and I can appreciate that POV.
Cal described Bruce at lunch once thinking out loud about how resistor distortion might arise, doing the napkin maths, and going back to the lab and verifying his surmise.
This was many years ago. I think that is nonetheless one of the topics he discussed last night at the local AES, which I wished I could have attended but ultimately decided against.
Hi,
This my response to the final ejaculation in this, hence my point that claiming any THD or even single Harmonics HD Number is audible or not is useless unless qualified by SPL and Frequency.
A lot of distortion at high SPL's cannot be heard (I do think I related the story before where our earplug wearing Light Man complained my mix on the PA was distorted and I could not hear the distortion until I put >20dB attenuating earplugs in myself).
Yup.
Actually, "magic" is exactly that. Advanced technology. In the case of stage magic, that of deception.
In my experience anything "magic" has explanations that with sufficient hindsight seem rational, or at least can be explained in rational terms.
Without such benefit they appear "supra-natural" to all observers and we get the point where those inclined to excessive rationalism reject these because it does not fit their weltanschauung and intellectual constitution, while others take an excessive attachment to the apparent "supra-natural" part.
In reality they are all like the blind men who went to visit the Elephant...
Ciao T
This my response to the final ejaculation in this, hence my point that claiming any THD or even single Harmonics HD Number is audible or not is useless unless qualified by SPL and Frequency.
A lot of distortion at high SPL's cannot be heard (I do think I related the story before where our earplug wearing Light Man complained my mix on the PA was distorted and I could not hear the distortion until I put >20dB attenuating earplugs in myself).
Yup.
Actually, "magic" is exactly that. Advanced technology. In the case of stage magic, that of deception.
In my experience anything "magic" has explanations that with sufficient hindsight seem rational, or at least can be explained in rational terms.
Without such benefit they appear "supra-natural" to all observers and we get the point where those inclined to excessive rationalism reject these because it does not fit their weltanschauung and intellectual constitution, while others take an excessive attachment to the apparent "supra-natural" part.
In reality they are all like the blind men who went to visit the Elephant...
Ciao T
Hi,
The whole point of recorded music is an illusion. It is "magic" on a high level.
So it follows the laws of magic, not those of science...
There are no lies in music, only distortions, of all sorts.
Ciao T
The whole point of recorded music is an illusion. It is "magic" on a high level.
So it follows the laws of magic, not those of science...
There are no lies in music, only distortions, of all sorts.
Ciao T
That's a bit extreme, don't you think?
Ultimately, some forms of alcohol are good for you, as long as they are kept within reason. Beer for example cleans up your kidnies like few other things and is second only to the watermelon. A pint of beer a day keeps the kidney stones away. My dad had problems with kidney stones and beer sure helped him, even if he didn't particularly enjoy it. He was an express milk drinker, and since milk is full of calcium, it was probably that, coupled with low during the day water drinking, which gave him the stones.
Wine, especially red wine, gets rid of excess cholesterol in your blood vessels. It is advised that you drink a glass of it with every lunch you take. Look at the Mediterranean region, where wine is commonplace and obligatory; their incidence of problems with intestines and stomach in general is an order of magnitude below non-wine drinking countries.
That dry, I simply must ask - are you SURE you're British?
But neither is the default.
I've heard so many rather poor, loose and unfocused tube gear I hate to even remember it - it was made to cash in on tubes present, I think, rather than being designed seriously.
As for the transistors, they too can be - and are - made to sound heavenly. Again, not any default. The fact that tubes are said to sound better is also heavily influenced by the fact that for every tube amp made, there must be hundreds of transistor units made, so the generalization is stilted by the numbers.
However, I agree that we could have one measuring much better than a tube amp, and still have the tube amp sounding better, although that's far more rare than is admitted by the tube heads.
While our measurements can tell a lot indeed, they still cannot accurately tell the whole story.
"There are no lies in music, only distortions, of all sorts."
Not true. I remember an interview with Billy Joel talking about how to "lie" in a performance. How not to play notes and make the audience not miss them. He cautions to not listen too carefully to a lit of live performances. That's artistry.
Out ability to capture sound, store its information, and reproduce it is so poor, we are interested in what lies make us think what we hear is music. That does not mean we should quit removing distortions and making it better step by step.
Not true. I remember an interview with Billy Joel talking about how to "lie" in a performance. How not to play notes and make the audience not miss them. He cautions to not listen too carefully to a lit of live performances. That's artistry.
Out ability to capture sound, store its information, and reproduce it is so poor, we are interested in what lies make us think what we hear is music. That does not mean we should quit removing distortions and making it better step by step.
Dejan,
You are doing exactly what you claim to hate if others do it. You make absolute pronouncements, rather than stating personal preferences...
Yet most sound TO ME like having gravel shoved up your rear opening. On a good day. Then again there are those who like that kind of thing and they are welcome to their pleasures...
Actually, past certain very basic levels, our conventional measurements tell feck all.
Ciao T
You are doing exactly what you claim to hate if others do it. You make absolute pronouncements, rather than stating personal preferences...
Yet most sound TO ME like having gravel shoved up your rear opening. On a good day. Then again there are those who like that kind of thing and they are welcome to their pleasures...
Actually, past certain very basic levels, our conventional measurements tell feck all.
Ciao T
Hi,
That is "distortion and illusion", surely?
I do agree.
However, when a given distortion has been reduced below audibility, is there any point reducing it further while neglecting to others that are still audible?
To wit, what is the point of Amplifiers with 0.0001% 2nd HD at rated power (to not have to give DF96 another fiver for using the TLA staring with T) if speakers have 10% 2nd HD at rated power?
Matthew 7:5-6
Ciao T
That is "distortion and illusion", surely?
I do agree.
However, when a given distortion has been reduced below audibility, is there any point reducing it further while neglecting to others that are still audible?
To wit, what is the point of Amplifiers with 0.0001% 2nd HD at rated power (to not have to give DF96 another fiver for using the TLA staring with T) if speakers have 10% 2nd HD at rated power?
Matthew 7:5-6
Ciao T
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