I understand what you're saying for the AMP section of an amp ( lowercase = total package of what you buy in the store). But commercial amps also have bass, treble, maybe loudness, subsonic filters and who knows what else. Bass and treble 'crossovers' (not sure if that's the right term but u know what I mean) may be assigned at different frequencies. I think this might be in part where audible differences come in. Possibly some amps allow for more distortion to make it sound bigger (like older, 1980s Harmon Kardons... but I'm not sure).
Our HK and NAD have always sounded quite different. Every amp/receiver I've owned has had its own sound. If anyone cannot hear that, they might have less than idea hearing, imo. And that includes Mr. QUAD too.
Again, I do understand electrical similarity. But you talk about similarity, not equality. From my experience, due to the very complex nature of sound waves, even small differences can make an audible difference.
Example - I mix my own original songs in Reaper, a Digital Audio Workstation. Reaper allows users to render their project to a WAV file with a variety of settings. Some people might not be able to hear the difference among settings but others can. The differences are subtle but those waves bounce around and create all sorts of interference all along the frequency range (which you can see with meters). And different render settings, even small ones, make a difference how that complicated interference takes place.
With Reaper we can check A and B sound files for equality or difference using a phase test. We simply invert the phase of one file and play the two files together.
If they are the same, they cancel each other out and there is no sound. Meter reads 0db thru the whole song. If they differ, we can hear sound because they do not cancel each other out. And the db meter shows this too. Instead of 0, there is deflection (to use the old term).
I wonder if the A and B signals you talk about would pass a digital phase test. I doubt it.
And these different signals interact with all other factors we've discussed before they hit our ears.
So I'm inclined to think there would be audible differences among amps, even in the AMP phase. But again, one has to have ears to hear it, imo.
Just because Mr. Quad was good at electronics does not necessarily mean he was a good listener.
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Dating from 1990? LOL That sounds pretty new to me, but I guess I'm an old fart. On the other hand , I have a receiver that I bought 10 years later ~2000+ that used 4558 op-amps SIPs, so I upgraded them a bit, on the cheap. I had the impression that consumer products just didn't care about the finer points of audio quality any more. Or maybe it's just the modest price range that I could afford.
My first amp was a Maplin 225WRMS into 4 ohms 2n3055/MJ2955.
It was run on too high voltage power supply but seemed to work very well.
I used the amp on a mobile disco for a few years and it took some stick.
It was very loud and sounded great.
It was used in conjunction with 4 Fane 12-50WRMS speakers.
I have designed and built numerous amps since but none seem to sound much better or worse than that one did.
I stick with my Fane speakers and still have a 1980's Fane 12-50WRMS in a W bin which I listen to mostly.
It was run on too high voltage power supply but seemed to work very well.
I used the amp on a mobile disco for a few years and it took some stick.
It was very loud and sounded great.
It was used in conjunction with 4 Fane 12-50WRMS speakers.
I have designed and built numerous amps since but none seem to sound much better or worse than that one did.
I stick with my Fane speakers and still have a 1980's Fane 12-50WRMS in a W bin which I listen to mostly.
What is a good audio amp? Technics power amp SE9600. Is this a good amp?
Power output: 110 watts per channel into 8Ω (stereo)
Frequency response: 5Hz to 150kHz
Total harmonic distortion: 0.08%
Damping factor: 100
Input sensitivity: 1V
Signal to noise ratio: 110dB
Speaker load impedance: 4Ω to 16Ω
Dimensions: 450 x 193 x 426mm
Weight: 23.6kg
Year: 1974
I owned one and it sounded grainy. It, and the partnering preamp looked the part. The preamp (discrete) had a design flaw, which after fixing, sounded better (to my ears) than a much more modern OP275 opamp based preamp. Photos from hifiengine. Current flow on the PCB can have a bearing on sound quality which steady state measurements will not reveal.
Attachments
Yes, this is always the proposed "answer"...the people who think they hear non-existent things have golden ears, and the rest of us simply have flawed hearing.
While there are definite differences in sensory abilities, all humans fall within a range. No human can jump 50 feet; no human can lift a railroad car; no human can see infrared; no human can hear 50 kHz.
The range of normal human hearing has been well studied for about a hundred years now, starting with researchers from Bell Labs, who were very keen to know about human hearing in order to design better telephone systems.
Trust me, you don't have magic hearing that can hear things that nobody else can. Nobody does.
Again: If the difference between the output and the input is *below the threshold of human hearing*, then it is physically impossible to hear any difference.
There is an interesting physical limit that sets the ultimate lower limit of hearing. The "shot noise" of moving air molecules in the air around you bouncing off your ear-drums, vibrates them slightly, and this noise actually sets an absolute limit to the quietest sounds you can hear, even if you had mathematically perfect hearing.
And yes, there are in fact audio amplifiers that produce (noise+distortion) levels so low that they are below this fundamental noise threshold itself...literally, quieter than the air in the room.
We are always free to imagine we hear things, however, and being fallible human beings, we will almost certainly hear what we expect to hear.
Sound waves - from the loudspeaker? Sure, loudspeakers have quite sizeable flaws, and most of us can easily hear those flaws. That's why several people on this thread have said the same thing: to improve the sound, focus on the speakers, and the listening room.
Electrical signals representing sound waves, in the preamp/power amp? Those are exactly the signals that you should use with the amplifier A-B test. Not continuous sine waves, but Beethoven, or Diana Krall, or Lynyrd Skynyrd, or whatever your preferred music is.
The "digital phase test" is a red herring. If the output signal differs from the input signal by so slight an amount that it is below the threshold of hearing, all other testing is irrelevant.
That is exactly why this is the single test that answers every argument about the plethora of "normal" tests people do. People can always argue about waterfall plots, transient intermodulation distortion, damping factors of 15000, thumb-thick speaker cables, and other nonsense. But if A-B=0, it doesn't matter how many mpingo disks were in the room, or not: if A-B=0, there is no difference between A and B. And if A-B = epsilon, where epsilon is a tiny quantity below the threshold of human hearing, or perhaps even below the shot-noise limit of the human eardrum in room-temperature air, then there is no audible difference between A and B.
The test has been done with both analogue and digital sources. In the early (1960's?) tests, power amps were not DC coupled, so some amount of LF phase shift was to be expected; this would be matched with an adjustable RC network in the subtraction channel.
These days, there is less need for any sort of phase matching when doing the subtraction test, because most power amps are DC-coupled most of the way through, unlike the days of valve Hi-Fi.
Signals from the speakers? Sure. Yes, you can hear speaker imperfections. Yes, you can hear room imperfections. Yes, you can hear speaker-room interactions.
That's exactly the difference between superstition, and science/engineering. We might be inclined to believe there is a magic lava-demon living inside the big gnarly tree, but we would be wrong. We might have eyes that think they see the face of Celine Dion in a moldy tortilla, but she is not actually there, and the face we think we see is merely a figment of our imaginations - it isn't actually real.
You're missing the most important thing: in the sense that you're using the words, the fact is that there are no "good listeners".Just because Mr. Quad was good at electronics does not necessarily mean he was a good listener.
The nature of human hearing is fundamentally flawed. We are all easily and repeatedly fooled by our hearing, sight, touch, sense of smel, sense of taste, sense of temperature, sense of balance. Human hearing, like all human senses, is extremely failure-prone.
We see things that aren't there: Akiyoshi's illusion pages
We hear things that aren't there: YouTube
Don't trust the evidence of your senses for evaluating anything that evolution didn't design them to do. They won't do a good job of it. That's why a $100 microphone is still a thousand times better than your ears at measuring the frequency response of a loudspeaker, for instance. (But your ears & brain can pick out the voice of your friend in a noisy cafe, where the microphone fails utterly.)
-Gnobuddy
Simple, if there really was audible amounts of grain, it would immediately show in an output-input test. And if the A-B test did not show audible amounts of grain, then you weren't actually hearing graininess, only imagining it.
I have heard graininess from amps once or twice. The reason was always that the output stage bias was severely mis-set, and consequently there was lots of crossover distortion. Once the output devices were biased properly, the grainy sounds disappeared.
Steady state testing? One reason the A-B test was invented was to get away from claims that steady-state testing wouldn't reveal the truth. The A-B test is intended to be done with music, not with stead-state sine waves or what have you.
-Gnobuddy
Crossover distortion has to be really severe for you to hear it. Certain design topologies are more prone to it that others, and you still can't hear it. But putting that aside, your assertion means that Meas must have a 'bad' amp, or maybe both are bad, because he can hear a difference. If you need an AB test to determine if there is a difference between amps, then the amps sound the same to all intents and purposes. Why waste time on minutiae?
The implication of the assertion of the 'good amp existing for decades' is that the necessary sound quality has been achieved in abundance and seekers of better sound quality are wasting their time. So name four mass produced amps, successively five years apart that sound exactly the same as Hypex Ncore amps.
The implication of the assertion of the 'good amp existing for decades' is that the necessary sound quality has been achieved in abundance and seekers of better sound quality are wasting their time. So name four mass produced amps, successively five years apart that sound exactly the same as Hypex Ncore amps.
So we have two completely different branches of science, both with rather highly developed and sophisticated bodies of knowledge.
The first concerns our theories of electronics, which tells us that two amps which measure the same, or measure with inaudible differences, should sound the same.
The second concerns our theories of psychology, which tells us there are perceptual biases which explain why someone may very well be convinced he/she does hear a difference when there is none. Those biases have been studied and verified, over and over again. They have names, like expectation bias and confirmation bias, and they are as much a part of the psychology body of knowledge as the Miller Effect is to electronics.
And yet, there are those who choose to dismiss both fields of science, and declare that they, along with a few chosen others, are not only immune to the psychological biases, but also thumb their nose at electronics theory as well.
Go figure. Occam's Razor says the simplest solution is the most probable, and that seems to be that there isn't any difference to be found.
The first concerns our theories of electronics, which tells us that two amps which measure the same, or measure with inaudible differences, should sound the same.
The second concerns our theories of psychology, which tells us there are perceptual biases which explain why someone may very well be convinced he/she does hear a difference when there is none. Those biases have been studied and verified, over and over again. They have names, like expectation bias and confirmation bias, and they are as much a part of the psychology body of knowledge as the Miller Effect is to electronics.
And yet, there are those who choose to dismiss both fields of science, and declare that they, along with a few chosen others, are not only immune to the psychological biases, but also thumb their nose at electronics theory as well.
Go figure. Occam's Razor says the simplest solution is the most probable, and that seems to be that there isn't any difference to be found.
The original question is how do good old amps compare to those available today from stores (not dedicated dealerships)?. The short answer is they probably compare quite well, but as in anything, there are good and bad examples. But the premise of some, is that newer models can't be better than the old ones since the required quailty level was achieved decades ago. Modern improvements are inaudible. So still loosely on topic.
The difficulty is determining what makes a 'good' amp. Referring to input and output is meaningless because there are no parameters attached. There are engineering reasons for amplifiers sounding different. Experienced practitioners of this forum are not hallucinating or judging with bias. The mains supply at the top of a tall building can have reduced quality compared to the ground floor. I chose the Hypex for comparison since it doesn't need a power conditioner. Can this be said of amps from yesteryear?
Paul Miller devised a test for dynamic performance. His results show differences between input and output. So where do you set the performance level?
The two Peters, Baxandall and Walker are acknowledged geniuses of the audio world. But not everything they uttered becomes a universal truth. Baxandall made observations about feedback that distinguished individuals have repeated. Some of these observations have since been shown to be false.
Peter Walker in his observations, did not fully disclose the surrounding parameters. From what I remember (someone correct me) he was comparing a Quad II with a Quad 303. If he was using a Quad ESL 57 for his listening, then attributes of bass performance may have gone unnoticed. If that was his comparison, are we now saying that valve amps sound like solid state ones?
The difficulty is determining what makes a 'good' amp. Referring to input and output is meaningless because there are no parameters attached. There are engineering reasons for amplifiers sounding different. Experienced practitioners of this forum are not hallucinating or judging with bias. The mains supply at the top of a tall building can have reduced quality compared to the ground floor. I chose the Hypex for comparison since it doesn't need a power conditioner. Can this be said of amps from yesteryear?
Paul Miller devised a test for dynamic performance. His results show differences between input and output. So where do you set the performance level?
The two Peters, Baxandall and Walker are acknowledged geniuses of the audio world. But not everything they uttered becomes a universal truth. Baxandall made observations about feedback that distinguished individuals have repeated. Some of these observations have since been shown to be false.
Peter Walker in his observations, did not fully disclose the surrounding parameters. From what I remember (someone correct me) he was comparing a Quad II with a Quad 303. If he was using a Quad ESL 57 for his listening, then attributes of bass performance may have gone unnoticed. If that was his comparison, are we now saying that valve amps sound like solid state ones?
Haha. You make a pretty good argument but I still disagree. Or might disagree. One thing you overlook in your analysis is that hearing is not just about the ears. Some folks might have a higher degree of specialization in brain areas linked to hearing. Like Einstein, for instance, when they sliced up his brain after his death, he had a high degree of specialization in imaginative thinking.
Another factor, which I do not expect you to agree with, is the possible role of spiritual factors in hearing. I'm not talking about hearing voices, audio hallucinations or anything like that. But I am talking about spiritual presences enhancing our perception.
My point - it's not just about the ears. And... I think a few folks can actually hear beyond 20k Hz but on that I'm not 100% sure. I'd have to Google it...
But before I finish, I should say that I partially agree. I have fooled myself from time to time with experimenter bias, or whatever we want to call it. We hear what we want to hear, to some extent. If I think an mp3 sounds worse than a wav, I tell myself that and that bias influences my judgment while comparing.
Mind you, if you played the same source thru the amps I have in our house, I would hear the differences. They are too clearly different to miss. But again, this is my definition of amps, as amps also in receivers with all sorts of other stuff added into the unit (which probably is what most effects output).
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We had some late 70s Genesis loudspeakers that I ditched. I sort of wish I kept them even if the baffles were shot. They sounded good with our HK amp because it is not as clean as the NAD. The harsher amp with a polite speaker was a good combo...
I don't really know the technical difference between op and discrete. But I imagine it's something like computers... better to have a discrete video card than an integrated one.
I see that the public generally prefers discrete over 'regular' amps (from looking at the box store website comments and ratings).
Roger that. I like my old Marantz gear because I can work on it. If a discrete component goes bad, I can change out the component and move on. With the new integrated boards, you can usually only troubleshoot to the board level, and need to buy the entire board if something on the board is bad. Like modern cars, they sometimes will give a trouble code.
There are a lot of times where I wonder if the only reason I like the sound of my old amps is only because I repaired them?
There are a lot of times where I wonder if the only reason I like the sound of my old amps is only because I repaired them?
I'm not a fan of Occam's Razor. Life is a complicated thing. And to lean toward simplistic answers to that complexity is both biased and potentially flawed, imo.
Science is a human enterprise and thus itself subject to bias. Many who staunchly uphold it do not realize they are likely missing variables they haven't considered.
btw... sorry again for not multi-quoting. I'm doing this on the fly during stolen moments on a busy day.
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Hi, I think you are asking the wrong question, What about class D / T amps.
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So the answer is go buy a modern Class D, even the 3116 is now out of date.
Cheers
I didn't even know what a Class D amp was. Just had to look at Wikipedia. But methinks it is well beyond what I'm hoping to spend!
I have an old NAD which I may or may not have overheated. Another poster suggested I crack it open and inspect the caps. Well, I'm sorta afraid to do that. So I'm listening to it these days wondering... does it sound different..? did I wreck it? Or is it just the same?
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