The Audio Path In Consumer-Grade Products

Discussion in 'Amps, Pre-Pros & Receivers' started by <eargiant, Aug 9, 2017.

  1. Pogre Audioholic Ninja

    Pogre
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    I also agree with another observation made in this thread. You have a little issue with comprehension. Some of your replies make no sense to the point of babbling. It's like trying to discuss logic with a religious fanatic. Most of what I, or anyone else types just goes completely over your head.

    *Edit: If 100 people could hear something no one else can, wouldn't that make them the only 100 on the planet that could tell the difference..? I'm not clarifying that again. You need to comprehend what I'm typing. You're having trouble with comprehension all through this thread from the beginning.
    Last edited: Aug 12, 2017 at 4:47 PM
  2. <eargiant Audioholic

    <eargiant
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    I've tried to be as civil and as friendly as possible while stating my points for the sake of this discussion. I wish I could say the same for you and a couple of others that resort to ad hominem attacks when pressed...
    Last edited: Aug 12, 2017 at 8:05 PM
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  3. lovinthehd Audioholic Spartan

    lovinthehd
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    Another thread with no basis for golden ears derailed, funny how that works. I admit I was the one who said perhaps to hear such minor differences in apparatus one needs a butt clenching listening session which doesn't sound like as much fun as simply listening to content. To try and hear minute differences between electronics (let alone all the various possibilities of pre-amps/amps/avrs and all the time that would take to do a reasonably good job comparing them for significant audible differences....got much better things to do). I've done it with good 2ch separates and avrs and find its not worth the effort/time personally.

    I'm still waiting for the obvious differences to manifest themselves, and IME they don't live up to the billing of the golden (or giant) ears....
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  4. <eargiant Audioholic

    <eargiant
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    Last edited: Aug 13, 2017 at 6:45 PM
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  5. lovinthehd Audioholic Spartan

    lovinthehd
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    Still, it doesn't convey perhaps what you think. I think you're the Don Quixote for electronics making huge differences in this forum, tho :)
  6. killdozzer Full Audioholic

    killdozzer
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    @<eargiant Would you say you'd still be able to take a step back and look at the whole of your thread? I know debates can be aggravating and polarising, but what you seem to have done is reveal that your true intention was not withheld in your apparently benign first post where you merely ask for some opinion. Because when you got them, you fell into this honey badger's pit, clawing at everyone.

    Here's a nice example. Do you know how long human beings exist, would be my first question? Now, I'm also a noob and I might find myself in a position to choose between what you preach and what is being preached here in audioholics. I hope you can see why I wouldn't opt for your persuasions. You offer haze. Think of all the amps you haven't heard, you might as well own the worst one, right?

    Here's another example:

    And yet these guru's seem to perfectly reliably utilise these "millions of years" of evolution of human ear?? Every time they opt for a tube, for example, it seems they hit exactly the spot of all those "millions of years", could you envision what this would mean for the discovery of the tube. It would present a one in a google odds. Where are all the trials and errors of these gurus?

    And once you learned your experience may be preset with wording, you may start avoiding what guru's say all together.

    These are just some of the examples why even someone who doesn't know much about audio would steer clear of your bold claims.

    In the end you acquired the form of a snake oil marketer who aims to up his game and find new ways of disarming the arguments of his opponents through forum quarrel which would offer insight into what is stopping the people in buying esoteric gear. (I base this entirely on my own experience so you can't say I'm wrong, you can, following your logic, only say you haven't had this experience)



    I'm so glad you asked this question. It's been bugging me for years. I see this as a perfect question to be posed at snake-oil vendors, it's like;

    It is there, it is not measurable, but we have a perfectly reliable insight into all this that's not measurable and produce our equipment accordingly.

    I mean, wouldn't it be highly, I mean HIGHLY beneficial to rather start working on that missing measuring device that would once and for all prove that we all need to buy expensive and esoteric gear if we want to enjoy? If your entire production depends on it, it would come in handy...

    This way it is perfectly clear they have a whole industry whose production process is entirely based in the non-measurable! Well ain't that just dandy? Can you really go wrong then?
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  7. Irvrobinson Audioholic Ninja

    Irvrobinson
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    I was thinking about this statement... why would this be the case? Any Class AB amp is going to be running in Class A at 0.01 watts.

    Of course, even if that is true, I think the entire question is silly for most of us. Most rooms I've measured have an ambient noise level in the 40-45db range on the quiet side, and the 50db+ range with refrigerators, HVAC systems, and street noise. With speakers that are typically (in reality) 86db/2.83v/1m, is 0.01 watt really a useful volume level for listening tests? Perhaps with Klipschhorns. ;)
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  8. PENG Audioholic Warlord

    PENG
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    Not really, some (I would guess most AVR, mid range integrated/Power amps) run at class AB all the way, some do it up to fractional watt to quite a few watt. Like other things they do, all over the map. Take a look of some so called bench test graphs, you will see that at very low output, THD+N climbs on a steep slope, and that's just THD. In that particular low output level test, even class A amps wouldn't make much different because the THD+N would still be higher in terms of %, unless the class AB amp used for comparison has really high cross over distortions, that's another variable the tester could choose.


    ATI amp
    [​IMG]


    [​IMG]




    Anthem MRX-710

    [​IMG]

    I want to keep our friend <eargiant happy so I don't really want to say this, but now that you mentioned it I've got to be honest. To me it is highly suspicious that they would do it at such low level and using a single sine wave of 1kHz. Thank goodness Goliath picked that up and as he mentioned, in DBTs where music was used, there would be all sorts of masking effects. Also, as John Siau himself pointed out, at 0.01W distortions produced by the speakers would be very low so again, it makes it easier to hear the difference in amps and other electronics in the chain.

    We all know at normal listening level, say 1W, distortions by speaker are much higher than that produced by amps. So it seems to me Mr. Siau test was designed to prove that amps "CAN" sound different, kind of stating the obvious. What is no so obvious is whether well deigned amps operating within their limits would sound all that different when driving commonly found speakers in people's homes, and often listening to "amplified" music to begin with.
    Last edited: Aug 13, 2017 at 8:52 AM
    PENG,
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  9. PENG Audioholic Warlord

    PENG
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    This is an interesting thread and you are doing a good job keeping people engaged, hope you can manage to keep it that way, say for at least another week.:D:D
    Last edited: Aug 13, 2017 at 9:09 AM
    PENG,
  10. sterling shoote Senior Audioholic

    sterling shoote
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    This thread has made me think about the thousands of posts to this forum which debate what technologies used to enjoy recorded music actually improve our music listening experience. So far, comparing my circa 1959 Magnavox Transistor Radio to my iPhone 7 Plus, I can, for sure, say the iPhone delivers better sound in all manner that better can be discerned. It's just amazing, Now, I suppose, if we looked at the technology of these two devices, we would be able to understand why the iPhone sounds dramatically better and transfer that knowledge to our overall understanding of what is in fact important to reproducing more life-like music. At any rate, seems to me, what most effects our impressions of a great stereo or multi-channel AVS today are its speakers, with bigger still being better, i.e. JBL 4367 in comparison to one of their small monitors.
  11. Swerd Audioholic Ninja

    Swerd
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    I couldn't disagree more with you.

    I don't read your posts as civil or friendly – they're needlessly argumentative and provocative. It's as if you like arguing and deliberately prod people into responding. I personally dislike this method. Perhaps you're a lawyer, or should be.

    Your arguments about the evolution of human hearing are unscientific and absurd. They are among the worst examples ad hoc thinking I've seen in sometime.
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  12. <eargiant Audioholic

    <eargiant
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    For years the earliest human, Australopithecus afarensis was known to have existed 3.2 million years ago. She held the record for quite a while. The mantle has been taken over by Ardipithecus ramidus so the human timeline has been pushed back to 4.4 million years.
    Last edited: Aug 13, 2017 at 10:55 AM
  13. Pogre Audioholic Ninja

    Pogre
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    That's not the only sentence he typed in that post, but in a discussion about whether something is audibly different, that's the one sentence you chose to quote.

    Another post that went completely over your head.
  14. <eargiant Audioholic

    <eargiant
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    Relax, I only had time to answer his first question.

    I'm compiling a list of papers to post for your perusal.
  15. Irvrobinson Audioholic Ninja

    Irvrobinson
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    You've lost me. The definition of a Class AB amp is that it runs in Class A up to a certain voltage level, the so-called bias voltage, and then operates in Class B. Yes, it's always in Class AB, but at 0.1 watts I would guess that every Class AB amp is operating in Class A.

    0.005% is about -86db, so I suspect those graphs rise at low power levels because you can't measure the distortion through the noise.
    Last edited: Aug 13, 2017 at 4:30 PM
  16. <eargiant Audioholic

    <eargiant
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    So, I haven't been able to find the exact paper I had in mind yet (I'm also trying to enjoy the beautiful weekend outdoors and also spending some time listening to music) but I figured I'd post these in the meantime to support my response to Goliath's claim that-

    "Human hearing has thresholds for what can and can't be heard and these thresholds are well known"

    After all, my response and disagreement seems to be what got a few of you into a tizzy. While on it's face, his statement seems to be a factual -the science is NOT settled. That's the beauty about science, it never rests on it laurels and is always inquisitive. Always digging deeper and challenging previously held beliefs with new studies and research.

    How we perceive sound around us is an area that is not fully understood- far from it. Our aural perceptions are not limited within a 20Hz-20kHz realm.

    Since we are talking about music listening, ultimately it's about what we perceive. The science of how we perceive and process sounds is NOT settled, as I said- far from it.

    Here are a few links for you guys to start with. I'm particularly interested in the one published by Tsutomu Oohashi in the American Physiological Society's Journal of Neurophysiology. Take a look at those EEG brain scans. So even when the participants didn't think they heard it- they perceived and preferred it (as evidenced by their brain scans).

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4744263/

    http://jn.physiology.org/content/83/6/3548

    http://www.icben.org/2017/ICBEN 2017 Papers/Keynote02_Koch_4163.pdf

    http://www.pnas.org/content/111/16/6104.full.pdf

    http://www.cco.caltech.edu/~boyk/spectra/spectra.htm

    http://journal.frontiersin.org/article/10.3389/fncir.2014.00116/full

    Agree or disagree, let's try to keep this civil. We can challenge the research and opinions without attacking those that espouse them.

    Maybe once we're done with this tangent we can join PENG & Irvrobinson and get this back on track.
    Last edited: Aug 13, 2017 at 5:15 PM
  17. PENG Audioholic Warlord

    PENG
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    I used to believe that too but something I read recently raised some doubt, enough for me to asked Verdinut to find out for sure when he was considering the QSC RXM850A, instead of assuming.

    http://forums.audioholics.com/forums/threads/crown-vs-rotel.106960/page-4

    In post#76 he said QSC told him that amp operates in class AB full time. To me, that means the amp is bias for better efficiency, minimize heat, resulting in a conduction angle of just a little greater than 180 degrees, i.e. barely class AB. That's just one example, but I don't remember everything I read so can't come up with more links at the moment.:D

    To run in class A in any meaningful way at all, I would imagine the angle has to be much greater than 180 degrees.

    I thought I should add that some of the googleable info on the internet can be misleading. Below is just one example:

    http://www.electronics-tutorials.ws/amplifier/class-ab-amplifier.html

    in that article it says:

    "....the Class AB Amplifier is a combination of Classes A and B in that for small power outputs the amplifier operates as a class A amplifier but changes to a class B amplifier for larger current outputs."

    That is misleading if not downright wrong. If you read the whole thing though, they did clear that point up, sort of..

    It is not relevant to our discussion but I though I should mention it in advance, in case others chime in and make that exact point.
    Last edited: Aug 13, 2017 at 7:00 PM
    PENG,
  18. Irvrobinson Audioholic Ninja

    Irvrobinson
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    Well, PENG, I've never heard of any definition or explanation like that. In a push-pull transistor pair there's a so-called "bias" current applied to the transistors that is usually constant. (Some amps, like some Krells and older Levinsons, to name two, have a feature called "sliding" or "dynamic" bias, where the bias level is adjusted in some increment in real time depending on the voltage of the input signal. But let's stick to constant bias for this discussion.) When the input signal is at a voltage that only requires current less than or equal to bias current for amplification, both transistors in the pair are powered to fully amplify the signal. As the current demand exceeds the bias current, one transistor gets a higher current than the other, depending on the phase of the input signal that is being amplified (since it's a differential pair), the current asymmetry between the two devices is my understanding of Class AB mode.

    Do you think this explanation is incorrect?

    Your conduction angle explanation seems like another way to describe the transition between symmetry and asymmetry in the current flowing through the transistors, but for some reason we seem to be talking past one another.
  19. M Code Senior Audioholic

    M Code
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    Keep in mind..
    Many well-known amplifiers brands/designers bias the output devices on the higher side so they are partially ON. This is done as to minimize crossover distortion...
    When a amplifier goes through its negative to positive wave swings, and the output device is OFF (no bias) when it turns ON it is very audible... Thats why certain Class AB amplifiers run on the hot side even when idiling without any audio processing as the output devices are partially turned ON giving off the heat...

    Just my $0.02... ;)
  20. Irvrobinson Audioholic Ninja

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    Who are you responding to? If the transistor has a bias current (as any Class A or AB amplifier does) it is never "off" by your explanation. The lack of a bias current designates Class B, unless I've been in the dark about transistors work all these years.

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