I do not see that logic. You can also conclude that your preamp gain changes do change the sound more than 5 opamps in series.
Knowing how meticulously double blind SY's test was, and having no idea about yours, I tend to go with my version ;-)
Jan
Not true. Lautsprechershop.de in Germany and it's owner Peter Strassacker suggest series woofer resistor as one of the best methods to tune modern high quality bass drivers that lack LF authority. The owner is pro!
I used a little bit of nichrome wire in the speaker lead to equalise the slight error in Q between a stereo pair of bass drivers.
I did not "invent" that idea. I must have read about it somewhere in the long distant past.
I have- it's not inspiring. But this relates to other phenomena unrelated to distortion. Far and away, the biggest limitation in home audio is the data loss from sampling a 3D sound field at two points (and even that sampling is flawed since the mikes have a frequency dependent polar pattern), collapsing the information into two one-dimensional signals, then feeding those two one dimensional signals into a pair of highly imperfect transducers with their own frequency-dependent polar patterns in a highly echoic environment.
So some would like an effects box in an attempt to make that experience more pleasant, and like I said, that's a valid design goal. But like all design goals, one has to be explicit about it and not rationalize that somehow it's more "accurate." To return things to the original topic, FB is the way one takes the electronics out of the equation, relegating to them the task of merely making small signals larger, and doing the effects elsewhere (in DSP of the source, in the design of the speakers, in the setup of the room). It's dull, it's something that was solved decades ago, and perhaps that's why there's an emotional investment in denying the data from actual listening tests.
Ironically, the demo that you created was, I think, a devastatingly clear demonstration of how poor our ears are at detecting low level distortions and noise in the presence of signal. It's one of the two reasons that I would put you in the DIYers' Hall of Fame, if such ever is created, on the first ballot.
Just look at the test results in stereophile for any boutique tube amplifiers that have just got rave reviews. The better the review the worse the performance of the amplifier generally. Sometimes I feel sorry for JA when he has to be politically correct when trying to explain why his reviewer loved something that is so bad on the bench.
Oddly the 2 amplifiers I have spent most of my adult life with got stinking reviews 🙂
Not sure why you are trotting out the 'scientifically proven' here. But if you are paying $10,000 for an amplifier do you really want 1% THD at 1W? People were getting that 50 years ago. But no I have not borrowed a 'recommended' boutique bling and compared it to a basic integrated at 1/20th the cost and 1/20th the distortion. But I stand by the statement that something that performs to 1955 levels of distortion is poorly designed. BUT amazingly well marketed 🙂
From Billshurv:
If some people think it is lovely, and you think it is terrible, then would you be interested to see how the THD is profiled; that is, would you like to know the harmonic profile? This might introduce the possibility that some people LIKE high THD. This might be a worrying development.......
Hugh
If some people think it is lovely, and you think it is terrible, then would you be interested to see how the THD is profiled; that is, would you like to know the harmonic profile? This might introduce the possibility that some people LIKE high THD. This might be a worrying development.......
Hugh
If I'm designing an effects box, I am certainly interested in the harmonic profile, but that's just a start.
It's important to define just what you want the effect to be, as with any other engineering exercise.
It's important to define just what you want the effect to be, as with any other engineering exercise.
There is no doubt in my mind that some listeners prefer added low order distortion.
The worrying part is that some of those listeners think that this is more accurate, or even "best".
Fortunately there are of few of those listeners that are well grounded in the science and accept that "less accurate" sounds nice.
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What has happened is that the high end audio business is littered with people who are technically ignorant. But, they are in the business of selling audio or writing about it to make a living. The problem is
1. They attemp to explain perceived differences using technical terminology and concepts about which they know nothing. In the big scheme of things, an amplifier is not a complex piece of engineering. However, the gap between those that understand the technical detail and those that have no chance of grasping it is huge. And there are orders of magnitude more of the latter with money to spend.
2. Some, who should know better, simply peddle nonsense - remember Martin Colloms 'feedback goes around a loop and arrives a bit late' article? Or Peter Qvotrupp [sp] from Audio Note assertions about the damage feedback causes and so on?
3. As Putzeys has remarked, there is a complete lack of probity and appreciation of scientific method in the industry. Why? Because commercial interests (money) demands the seller or reviewer say whatever they have to to get a sale or be heard. So it's not in their interest to stick to the facts, do DBT's (horror of all horrors - a $2k amp might easily match a $10k similarly rated product)
4. Finally, this has developed over the last 30 years or so into very niche business. It is not a technical market, but a luxury goods or enthusiasts market. When the CEO of Harley Davidson UK was asked a few years ago who he saw as his competition, he did not say Kawasaki, Yamaha or Honda. He said 'conservatories' (I think that's an atrium or garden house in the USA). In the UK, the people who buy Harley's don't buy them for racing around. They are statement products and the buyer has plenty of cash with which to indulge themselves in general. They come out on sunny days for a leisurely drive down country lanes, after which they are cleaned and polished, to sit another 3 months in the garage for the next break in the weather. It's the same with that $10k preamp, or that $30k turntable. The incremental improvement between a $300 turntable and A $30k one is marginal in the big scheme of things. But, some will fork out an additional $29700 for that.
Audio engineering is rational and well understood by the technically competent. The audio business is not rational.
1. They attemp to explain perceived differences using technical terminology and concepts about which they know nothing. In the big scheme of things, an amplifier is not a complex piece of engineering. However, the gap between those that understand the technical detail and those that have no chance of grasping it is huge. And there are orders of magnitude more of the latter with money to spend.
2. Some, who should know better, simply peddle nonsense - remember Martin Colloms 'feedback goes around a loop and arrives a bit late' article? Or Peter Qvotrupp [sp] from Audio Note assertions about the damage feedback causes and so on?
3. As Putzeys has remarked, there is a complete lack of probity and appreciation of scientific method in the industry. Why? Because commercial interests (money) demands the seller or reviewer say whatever they have to to get a sale or be heard. So it's not in their interest to stick to the facts, do DBT's (horror of all horrors - a $2k amp might easily match a $10k similarly rated product)
4. Finally, this has developed over the last 30 years or so into very niche business. It is not a technical market, but a luxury goods or enthusiasts market. When the CEO of Harley Davidson UK was asked a few years ago who he saw as his competition, he did not say Kawasaki, Yamaha or Honda. He said 'conservatories' (I think that's an atrium or garden house in the USA). In the UK, the people who buy Harley's don't buy them for racing around. They are statement products and the buyer has plenty of cash with which to indulge themselves in general. They come out on sunny days for a leisurely drive down country lanes, after which they are cleaned and polished, to sit another 3 months in the garage for the next break in the weather. It's the same with that $10k preamp, or that $30k turntable. The incremental improvement between a $300 turntable and A $30k one is marginal in the big scheme of things. But, some will fork out an additional $29700 for that.
Audio engineering is rational and well understood by the technically competent. The audio business is not rational.
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Separately, I have designed and built a number of low feedback amplifiers (sx and nx-Amplifiers) and one very high performance, low distortion amp (e-Amp).
I can honestly say that all of them sound to my ears very good on my speakers (and no doubt the other designs on the forum will also sound great). The point is, I personally would not agonize over distortion figures. There seems to be plenty of anecdotal evidence that distortion is not critical for musical enjoyment provided it's low enough to begin with. CleanpPower delivery into the speaker load, lack of response anomalies and stability seem to be the more important factors.
I can honestly say that all of them sound to my ears very good on my speakers (and no doubt the other designs on the forum will also sound great). The point is, I personally would not agonize over distortion figures. There seems to be plenty of anecdotal evidence that distortion is not critical for musical enjoyment provided it's low enough to begin with. CleanpPower delivery into the speaker load, lack of response anomalies and stability seem to be the more important factors.
put a few R in series to debunk damping factor. What's the worst that's going to happen? A ceramic resistor gets hot? Oooh.
I don't think it's terrible. I just don't like the fact that the more you pay the worse performance you get in some areas of audio. My current amp mimbles along around 0.3%THD. It's replacement will be 100 times better on distortion. Would I be able to hear that? Probably not, but as I am going active there is no way I can A/B it anyway.
Whilst we are discussing distortion I hope NP will not mind me posting this link. Pass Labs XA30.5 power amplifier Measurements | Stereophile.com . To me (and happy to be proved wrong) this shows a very carefully crafted 'house sound'. And other than the 19/20KHz test tone showing a bit more than one might like ( a whole 0.1%) everything else is down below what some sane people would say is clearly audible. And 2 thumbs up for advertising an amp at 30W class A but which happily delivers peaks of 130W in AB. I can safely say I would be happy to put one of those in my system should I ever get rich.
The worst ever were sold longer ago than that, at consumer rates, and purely by marketing, Mr Russell.
A single rich fool does not outweigh millions of gullible poor idiots.
(I met one who worked a low pay warehouse job in an airplane factory. After each and every biennial audio show, he bought new hype and the old stuff went out through the backdoor at fire sale rates)
I don't disagree, but it does beg the question: 'Then why are we here?.' And, I intend no facetiousness whatsoever. On the one hand we talk here as though we have the problem licked and how smart we are and so on, and on the other we gather here to talk about how different everything sounds.
Stanley Kubrick said, "If you can talk brilliantly about a subject you can create the consoling illusion that it has been mastered."
I'm just genuinely trying to understand if we believe there's still a frontier and if so what it might be. 🙂
Stanley Kubrick said, "If you can talk brilliantly about a subject you can create the consoling illusion that it has been mastered."
I'm just genuinely trying to understand if we believe there's still a frontier and if so what it might be. 🙂
whilst there are 'believers' there will be these debates. The frontiers are (IMO)as ever
1. speakers, which there are a lot of threads on and ongoing proper research into in the big bad world
2. proper multi-channel for music.Which is harder for the DIY crowd to deal with as we can't control the recording.
EDIT: 3. active systems. The lack of acceptance of these by the audiophile crowd has arguably held back a major source of improvement of sound in the home. But this on its own as a debate could run for 100 pages 🙂
If you define High end as something that has no obvious audible or measurable faults (other definitions exist) you can assemble a high end system for a few $K off designs on this forum that will perform at a very high level. And that's why we are here surely?
1. speakers, which there are a lot of threads on and ongoing proper research into in the big bad world
2. proper multi-channel for music.Which is harder for the DIY crowd to deal with as we can't control the recording.
EDIT: 3. active systems. The lack of acceptance of these by the audiophile crowd has arguably held back a major source of improvement of sound in the home. But this on its own as a debate could run for 100 pages 🙂
If you define High end as something that has no obvious audible or measurable faults (other definitions exist) you can assemble a high end system for a few $K off designs on this forum that will perform at a very high level. And that's why we are here surely?
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Jacco,
One man's ceiling is another's floor . . .
The guy could just as well of collected stamps, or photos of whatever. My main point was that if you sure rational, these things do not seem like good choices . . .
Personally I believe that as far as electronics for reproduction is concerned, we are able to design and build stuff that is better than what we can differentiate audibly. Note that I said 'we'- there's still stuff being produced that doesn't quite cut it of course.
With speakers we have some way to go. But, since stereo and such is all build on an illusion, it stands to reason that the next progress comes from creating better, smarter illusions. I've been privileged to attend demos both of Aura 3D and DTS 3D, stunning.
Why I am here: primarily for the electronic side of things. Musically I've been satisfied for the last few decades. I still experience differences between amps and such, for whatever reason, but not in the sense that one is 'bad' and another is 'good'. I like to design stuff in different ways, different ideas, and also to explain how things work to my friends.
Jan