Don't recall exactly, it wasn't my amplifier. I was working with someone else's system. But it was some type of two channel garden variety PA amplifier. Not Behringer. Maybe Peavey, or something like that. Rated right around 0.1% THD. The fellow who had it also had a used Bryston that had formerly been part of someone else's PA system. So he was using the Bryston for PA and the other amp for mixing on his DAW. I asked him why are you doing this? He was like, "what's the difference, they're both good amps?" So we tried both, and they were not both good amps. We switched them around and used the lesser amp for PA, and the Bryston with the DAW. Sounded much better. No more muddy sound. Or no more blurry sound, if that is a more clear way of explaining the difference. Like putting on corrective eyeglasses for the first time. Hey, you can see leaves on trees from several feet away!!
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Dear Evenharmonics,
Before I give you an answer to your question, I would like to know why you are so interested in what I do for myself?
Now, to your question. The "anyone who listens to a lot of different amplifiers" comment is more of a generalization. Just go over to solid state forum and read around and you will learn what people there do who make amplifiers and listen to them. If you think my statement is a lot of rubbish, okay that's fine. IF you think amplifiers sound the same then that's fine too. That's your business.
As to the "small circuit modification".... I have a close friend who designs amplifiers and shares the designs with me. I make pcb's of the designs and listen to the amplifier. Some times the designs are just small modifications of the previous designed amplifier. I listen and compare the old and the new for differences. The modifications are some times circuit changes and some times a resistor value is changed making a small difference in circuit operation. We assess the changes both on computer sim and in listening.
Does this help?
I'm interested in the claim you posted on this forum.
That's not what I was talking about.
That (bold) is what I was asking you about. How did you ensure that the difference in sound you perceived was actually caused by parts modification and not the volume level mismatch, placebo effect or faded aural memory?
Yes, it is quite true that I did indeed listen and compare. I don't deny that at all.
That is usually what one does with a music system, listen to music.
Listening also can be a good method of evaluation. But it depends on a lot of factors, including the ones you have listed.
But to get to what you have listed, why oh why would I not do my best to account for those things as I am quite aware of them. I have no real interest in fooling myself?
Thank you for showing so much avid interest in what I do.
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Are there parallels in 'Video Hi-Fi?' The light reaching your eyes can be described in terms of frequency and brightness. Get the correct brightness and correct colors and the image on a Hi-Def TV screen will look just like a real person standing next to it.
We tolerate colorations and lack of brightness in video, but claim that the picture represents reality quite well, is it the same for Hi-Fi audio?
Then there's the iPhone 7
https://www.cnet.com/news/iphone-7s...e-from-perfect-says-testing-firm-displaymate/
"indistinguishable from perfect" sounds familiar.
We tolerate colorations and lack of brightness in video, but claim that the picture represents reality quite well, is it the same for Hi-Fi audio?
Then there's the iPhone 7
https://www.cnet.com/news/iphone-7s...e-from-perfect-says-testing-firm-displaymate/
"indistinguishable from perfect" sounds familiar.
And my question was, how did you accomplish that? How fast was the switching between amps, how did you match the levels, how did you make the comparison free of visual bias and...etc.?
When deciding what is good enough, we may have to accept that senses vary from person to person.
For example, I seem to have a higher refresh rate for vision.
I notice any car with LED tail lights where they just chop the voltage to get half intensity. The tail lights appear as a series of dots when I pan my vision. I cannot believe that someone thinks such a tail light is acceptable.
I have also seen multi-colored LED stage lighting where they are obviously feeding the lights rectified but not filtered AC. The area seems lit and also not lit at the same time. Someone must think this is acceptable.
Another odd thing I have noticed with high frequency sounds is I may not seem to hear above 12Khz when listening for tones, but I will notice if I listen to music that rapidly falls off above 12khz.
For example, I seem to have a higher refresh rate for vision.
I notice any car with LED tail lights where they just chop the voltage to get half intensity. The tail lights appear as a series of dots when I pan my vision. I cannot believe that someone thinks such a tail light is acceptable.
I have also seen multi-colored LED stage lighting where they are obviously feeding the lights rectified but not filtered AC. The area seems lit and also not lit at the same time. Someone must think this is acceptable.
Another odd thing I have noticed with high frequency sounds is I may not seem to hear above 12Khz when listening for tones, but I will notice if I listen to music that rapidly falls off above 12khz.
Look, it's quite obvious that I did not do an ABX test. And I think it is fair to state that you are of the belief that ABX is the only true method to ascertain any difference between any two "things" in audio, whether diy or commercial. ABX can indeed be useful in some circumstances, but not all.
ABX was not needed for what I wanted to do. I was satisfied with the results. These results were verified by others in mutual satisfaction.
None of this is of any interest to you. If you don't want to believe that small changes in a circuit can change the overall performance or sound of an amplifier that's fine.
That's the end of this. I don't think there is anything more to discuss.
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I was just thinking of it but in different terms/vision
It is just the sync you see between the spoken and the labial that makes it so
natural
It's like the playback in tv shows for pop music
But often the difference for foreign movies or same nationality (it happened and it happens, also with an international cast with a common language )
for the spoken-labial sync is unberarable ...
Would you agree that our current instrumentation cannot (or will not) measure the relevant parameters that make up Hi-FI audio? If we are having a discussion about something we cannot measure, maybe that's the problem?
Nelson Pass
FIRST WATT FAQ
Nelson Pass
FIRST WATT FAQ
for the spoken-labial sync is unberarable ...
what a wonderful double-entendre. Made my morning.
Some people like to define Hi-Fi precisely in terms of measurements. Other people apparently prefer to define Hi-Fi as a possibly unmeasurable subjective experience. Those who prefer the former type of definition may object to the premise of your question. Those who prefer the latter type of definition will likely agree with you. Therefore, the problem at this point would appear to be more with disagreement on a suitable definition.
It might help strengthen the point of view for which you seek agreement if you could enumerate and define the relevant parameters that cannot or will not be measured.
Where have you heard that? Only an idiot would say that THD is the only thing which matters. Only an idiot would say that THD does not matter at all. I have never seen the former stated in this forum. I have often seen the latter stated.Markw4 said:
No. On the contrary, our existing measurements clearly cover at least most of what is needed for hi-fi. Anything they do not cover can be measured once we know what it is, and probably with instruments not much more sophisticated than we have now - or even our current instruments used with new interpretations.BasicHIFI1 said:
We can measure things we can't hear. We can't hear things which we can't measure, but we may hear things which for some reason we are not measuring. That is, if we can genuinely hear it then in principle (and almost certainly in practice) we can measure it.
Debate should thus be on two issues:
1. do we require better performance on those things which are often measured? (e.g. frequency response, distortion spectrum, hum, noise)
2. is there something else which we should be measuring too?
There is another group: those people who like to define hi-fi as a measurable subjective experience (e.g. indistinguishable from the real thing for X% of the population), and then from this derive measurements which will provide it. The measurements do not define hi-fi; instead they are an expression of our current understanding.Markw4 said:
These two positions appear to be, if not incompatible, then at least open to discussion. They appear to stem from a belief on your part. I, for one, am prepared to entertain the idea that we can hear things we cannot understand. And without understanding, how do you measure?
By "can't measure" I mean unable to measure, even in principle. In reality it may not even as bad as that: there is only weak evidence that we can hear anything which we don't measure, but I do not want to close the door on future developments. This is certainly my belief, just as the opposite position appears to be the belief of some others. The issue is 'which belief is most strongly founded on evidence?'.
For the avoidance of doubt, I will say again that I believe that we already know most of what needs to be known for hi-fi so discussion should be around whether we know 90%, 95% or 99%. I have little sympathy for people who believe that we know 20% or 50%, or that most of what we do know is wrong - fortunately it usually turns out that such people are not actually interested in hi-fi at all, however fervently they believe the opposite.
A quick test is to listen to music down a telephone line (4khz bandwidth, maybe 10% distortion?): if it sounds like the real thing to you then you don't need hi-fi; if it doesn't sound like the real thing then you have just confirmed that bandwidth and THD tell us something useful.
For the avoidance of doubt, I will say again that I believe that we already know most of what needs to be known for hi-fi so discussion should be around whether we know 90%, 95% or 99%. I have little sympathy for people who believe that we know 20% or 50%, or that most of what we do know is wrong - fortunately it usually turns out that such people are not actually interested in hi-fi at all, however fervently they believe the opposite.
A quick test is to listen to music down a telephone line (4khz bandwidth, maybe 10% distortion?): if it sounds like the real thing to you then you don't need hi-fi; if it doesn't sound like the real thing then you have just confirmed that bandwidth and THD tell us something useful.
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