bryansamui Posted September 12, 2020 Share Posted September 12, 2020 On 05/08/2020 at 6:13 PM, cazzesman said: https://www.soundstagehifi.com/index.php/opinion/1420-purifi-audios-pint-sized-powerhouses “The Purifi amp is so good, you no longer have to talk about quality!” he declared. “There is no harmonic distortion, no intermodulation distortion, no frequency-response aberration, regardless of frequency or load. It’s better than any other amplifier!” Regards Cazzesman "No Harmonic Distortion"? Funny world we live in... Nelson Pass adds it in deliberately... It's the 'Secret Sauce'.. Without 2nd Harmonics, it's like eating a burger 'Without Sauce' Clean, but bland as marble. 1 Link to comment Share on other sites More sharing options...
davewantsmoore Posted September 12, 2020 Share Posted September 12, 2020 15 minutes ago, bryansamui said: Nelson Pass adds it in deliberately I think that's a subtle misreprentation of what he does. Sure. He doesn't seek to minimise it.... and he is concerned about the harmonic profile. The thing is that you can't hear these amounts of harmonic distortion .... so then?!.... we would he do that? Why does it seem to matter. My view is that it is not the harmonic distoriton itself that you can hear (and enjoy). It is the things which the harmonic distortion is a symptom of..... which is the thing you are hearing (or not hearing). ie. it is the clipping, recovery, and intermodulation, performance of the amplifier.... which makes it "sound good". All amplifiers would (should) sound the same .....as long as they don't have any "tells" which make them sound different. Link to comment Share on other sites More sharing options...
bryansamui Posted September 12, 2020 Share Posted September 12, 2020 1 hour ago, davewantsmoore said: I think that's a subtle misreprentation of what he does. Sure. He doesn't seek to minimise it.... and he is concerned about the harmonic profile. The thing is that you can't hear these amounts of harmonic distortion .... so then?!.... we would he do that? Why does it seem to matter. My view is that it is not the harmonic distoriton itself that you can hear (and enjoy). It is the things which the harmonic distortion is a symptom of..... which is the thing you are hearing (or not hearing). ie. it is the clipping, recovery, and intermodulation, performance of the amplifier.... which makes it "sound good". All amplifiers would (should) sound the same .....as long as they don't have any "tells" which make them sound different. Nelson Pass builds and sells the "H2" . The unit sits between the Pre and Power amp.. It's a 2nd Harmonic distortion generator .. The idea is to make your amp sound like a SET amplifier. I've never heard one but some people swear by them... It puts back the those harmonics that of course naturally occur in a 'real live musical instrument' that get lost in the imperfect recording process. He builds this unit into his First Watt SIT 1 as a rotary control on the front (Add Salt & Pepper to taste) 1 1 Link to comment Share on other sites More sharing options...
davewantsmoore Posted September 12, 2020 Share Posted September 12, 2020 15 minutes ago, bryansamui said: Nelson Pass builds and sells the "H2" . Wow. That's new to me (welcome to 2019 dave) Link to comment Share on other sites More sharing options...
davewantsmoore Posted September 12, 2020 Share Posted September 12, 2020 16 minutes ago, bryansamui said: It puts back the those harmonics that of course naturally occur in a 'real live musical instrument' that get lost in the imperfect recording process. LOL x many 1 Link to comment Share on other sites More sharing options...
Volunteer sir sanders zingmore Posted September 12, 2020 Volunteer Share Posted September 12, 2020 25 minutes ago, bryansamui said: It puts back the those harmonics that of course naturally occur in a 'real live musical instrument' that get lost in the imperfect recording process. This has me puzzled. Are harmonics really lost in the recording process? And how does the H2 know which ones to put back? 1 Link to comment Share on other sites More sharing options...
bryansamui Posted September 12, 2020 Share Posted September 12, 2020 (edited) 41 minutes ago, sir sanders zingmore said: This has me puzzled. Are harmonics really lost in the recording process? And how does the H2 know which ones to put back? Yes harmonics are lost in the process, speaking from 1st hand experience as a professional musician. Even Vintage U47 Tefefunken Mics at $30,000 as good as they are won't make my guitar sound like the real thing . Regarding how the H2 avoids the nasty Odd Order harmonics,... I don't know the answer. Good question. Edited September 12, 2020 by bryansamui Link to comment Share on other sites More sharing options...
andyr Posted September 12, 2020 Share Posted September 12, 2020 (edited) 1 hour ago, bryansamui said: Nelson Pass builds and sells the "H2" . The unit sits between the Pre and Power amp.. It's a 2nd Harmonic distortion generator .. The idea is to make your amp sound like a SET amplifier. I've never heard one but some people swear by them... It puts back the those harmonics that of course naturally occur in a 'real live musical instrument' that get lost in the imperfect recording process. He builds this unit into his First Watt SIT 1 as a rotary control on the front (Add Salt & Pepper to taste) I suggest it's not just that 'these harmonics ' get lost in the recording process, Bryan. They may be lost by the amplifier circuit itself. I'm talking about the harmonic profile which any amplifier presents. AIUI, a tube amp will often have a high level of H2 ... and appreciable levels of other even-order harmonics. Whereas a nasty-sounding ss amp will probably (if it's nasty-sounding) have high levels of odd-order harmonics ... and not much in the way of even order harmonics In the latter case, the 'H2' adds the missing even-order harmonics to the ss amp's odd-order-heavy harmonic profile ... bringing it nearer to a tube amp's harmonic profile. Andy Edited September 12, 2020 by andyr 1 1 Link to comment Share on other sites More sharing options...
Grizaudio Posted January 6, 2021 Share Posted January 6, 2021 NP definitely plays with the harmonic profile, to provide great sound. To me, it seems he is concerned about the relationship/balance of harmonic distortion, and the performance of the 1st watt of amplification (the most important listening window). NP intimately understands the impact of an amplifiers distortion profile on imaging, tonal presentation, perceived detail, and the listening experience. As a Firstwatt F7 owner, all I can say, is he knows what he is doing. It’s a glorious sounding amp. 2 Link to comment Share on other sites More sharing options...
Grant Slack Posted January 12, 2021 Share Posted January 12, 2021 Like Nelson Pass, everything Bruno Putzeys says is pure genius, right up to, and not including, the moment he turns to the subject of audibility. That is the precise moment when they both step outside their zones of competence and don’t know it. cheers Grant 1 Link to comment Share on other sites More sharing options...
Stereophilus Posted January 12, 2021 Author Share Posted January 12, 2021 22 minutes ago, Grant Slack said: Like Nelson Pass, everything Bruno Putzeys says is pure genius, right up to, and not including, the moment he turns to the subject of audibility. That is the precise moment when they both step outside their zones of competence and don’t know it. cheers Grant Massive statement there Grant... To suggest that 2 of the most recognisable names in amplifier design today have no competence in what is audible is frankly preposterous. How can you ignore their combined decades of experience in listening and tweaking and measuring what they design?. Honestly, your statement leaves me dumbfounded. 3 Link to comment Share on other sites More sharing options...
Grant Slack Posted January 13, 2021 Share Posted January 13, 2021 It’s not preposterous, Stereophilus, it is simple: they have spent decades tweaking and measuring and listening, without controlling the listening to account for non-sonic factors. This is a fatal mistake. A routine, common and understandable mistake, but completely in violation of the science of human perception. Human perception is a science, too, and one that we audiophiles, not to mention product developers, are well advised to become more familiar with. The notion that being an electronic circuit genius makes one automatically a human perception guru, or above the laws of human perception — now, that’s preposterous. Bottom line: techie gurus who want to expand the frontiers of DAC and amp performance, are really doing it for those customers who want to pay for improvements in the inaudible part of the output of these products, just for its own sake. And I have no issue with that. I just wish these techie gurus showed a proper understanding of the science of human perception before writing or saying, “it sounded better”. Then they wouldn’t say it, and they could have a misdirection-free dialog with those customers who want bleeding-edge, next-level technical performance for its own sake. I, for one, greatly respect (and can admit to some lust for) the amazing technical results they can achieve. Ohhhh, I just saw your gear list, and it includes Mola Mola. Now I understand your reply, and I suspect the above-written comments, however factual, may encounter some resistance. cheers Grant Link to comment Share on other sites More sharing options...
frednork Posted January 13, 2021 Share Posted January 13, 2021 (edited) Pass is on record as using blind tests in amp development, Would be very surprised if Putzeys does not. Edited January 13, 2021 by frednork 1 Link to comment Share on other sites More sharing options...
Stereophilus Posted January 13, 2021 Author Share Posted January 13, 2021 46 minutes ago, Grant Slack said: It’s not preposterous, Stereophilus, it is simple: they have spent decades tweaking and measuring and listening, without controlling the listening to account for non-sonic factors. This is a fatal mistake. A routine, common and understandable mistake, but completely in violation of the science of human perception. Human perception is a science, too, and one that we audiophiles, not to mention product developers, are well advised to become more familiar with. The notion that being an electronic circuit genius makes one automatically a human perception guru, or above the laws of human perception — now, that’s preposterous. Bottom line: techie gurus who want to expand the frontiers of DAC and amp performance, are really doing it for those customers who want to pay for improvements in the inaudible part of the output of these products, just for its own sake. And I have no issue with that. I just wish these techie gurus showed a proper understanding of the science of human perception before writing or saying, “it sounded better”. Then they wouldn’t say it, and they could have a misdirection-free dialog with those customers who want bleeding-edge, next-level technical performance for its own sake. I, for one, greatly respect (and can admit to some lust for) the amazing technical results they can achieve. Ohhhh, I just saw your gear list, and it includes Mola Mola. Now I understand your reply, and I suspect the above-written comments, however factual, may encounter some resistance. cheers Grant We will continue to disagree regardless of my gear list. Why? Because I trust people who listen to their designs, and I trust my own ears as well. I do understand your contention - that all subjective experience must be controlled for to reach any valid conclusions. I just disagree in the same way that a sommelier with years of experience in selecting wines will sometimes disagree with a double blind-folded crowd of people about wine. We will not solve our differences here and now unfortunately. Suffice to say that this argument is beyond the scope of this thread. 2 Link to comment Share on other sites More sharing options...
muon* Posted January 13, 2021 Share Posted January 13, 2021 We need Grant Slack's internationally renowned amplifier designs 1 3 Link to comment Share on other sites More sharing options...
Steffen Posted January 13, 2021 Share Posted January 13, 2021 5 hours ago, Stereophilus said: We will continue to disagree regardless of my gear list. Why? Because I trust people who listen to their designs, and I trust my own ears as well. But that’s like saying “I trust my own eyes, and I’m telling you that space B is of a lighter shade than space A, science and measurements be damned”. 1 1 Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted January 13, 2021 Share Posted January 13, 2021 6 hours ago, frednork said: Pass is on record as using blind tests in amp development, Would be very surprised if Putzeys does not. Both do. @Grant Slack an overly simplistic and very incorrect view. Not least without subjective interpretations of performance we'd not have an industry. Link to comment Share on other sites More sharing options...
Stereophilus Posted January 13, 2021 Author Share Posted January 13, 2021 9 minutes ago, Steffen said: But that’s like saying “I trust my own eyes, and I’m telling you that space B is of a lighter shade than space A, science and measurements be damned”. There is a reason our brain sees B as a lighter shade than A. Our brains are programmed to make sense not of B vs A, but of that picture as a whole. I actually don’t care if they are the same shade or not, as long as the image makes sense. The information from measurement is useful, but it tells me nothing of the image I see. Now, the question becomes is the deception beneficial, or harmful? Not all deception is harmful. If it gives a clearer picture of the whole, and leads to beneficial outcomes then we need to embrace it and broaden our collective perspectives. Narrow-mindedly following the paradigm that our brains are wrong when there is objective evidence of a contrary truth can do a great deal of inadvertent damage, especially when the broader picture is lost. I do think there is an important place for objective understanding, but sometimes I want to just enjoy a picture of a green cylinder on a checker board, rather than compare 2 grey squares. 1 Link to comment Share on other sites More sharing options...
Steffen Posted January 13, 2021 Share Posted January 13, 2021 2 minutes ago, Stereophilus said: I do think there is an important place for objective understanding, but sometimes I want to just enjoy a picture of a green cylinder on a checker board, rather than compare 2 grey squares. I agree, but the point was that the science of human perception is a complex beast, and being human doesn’t make one an expert in it. I fully concur that being fooled can be enjoyable, and an experience to seek out (everybody loves magic shows, or movies, for example). I also recognise that things outside the physical reality of music reproduction (a nicely designed front plate, pseudo-scientific lingo to describe the construction of a cable, or merely a high price tag) can alter the perception of music playback, and make it more enjoyable to certain listeners. What I cannot go along with is when people insist that there are actual differences in the music reproduction, that some people with golden ears can hear, but instruments can’t measure. 1 Link to comment Share on other sites More sharing options...
Stereophilus Posted January 13, 2021 Author Share Posted January 13, 2021 4 minutes ago, Steffen said: I agree, but the point was that the science of human perception is a complex beast, and being human doesn’t make one an expert in it. I fully concur that being fooled can be enjoyable, and an experience to seek out (everybody loves magic shows, or movies, for example). I also recognise that things outside the physical reality of music reproduction (a nicely designed front plate, pseudo-scientific lingo to describe the construction of a cable, or merely a high price tag) can alter the perception of music playback, and make it more enjoyable to certain listeners. What I cannot go along with is when people insist that there are actual differences in the music reproduction, that some people with golden ears can hear, but instruments can’t measure. Kind of my point too... Human perception is extremely complex and not well understood even to this day. I keep coming back to the idea that only humans have perception of the whole. When people do insist they hear differences that are not measurable, in my view, it is because we do not yet fully grasp human perception in all its complexity. That is an issue of objective inadequacy, not subjective deception. Link to comment Share on other sites More sharing options...
Grant Slack Posted January 13, 2021 Share Posted January 13, 2021 2 hours ago, rmpfyf said: Both do. @Grant Slack an overly simplistic and very incorrect view. Not least without subjective interpretations of performance we'd not have an industry. I’m all in favour of subjective interpretations — validly conducted. You seem to have made an overly simplistic and very incorrect analysis of my view, if you think I am not. As for “both do”, well, it’s just too easy for them to say that, especiallly if they are saying that blind testing has shown audible improvements miles below the established limits of human sensory perception. If that is their claim, then they need to bring their findings into the harsh glare of independent verification. I’m guessing that hasn’t happened? Well then. Why, for example, would Putzeys do blind testing, if he is also willing to make the statement quoted here. “...for those people who say they tried feedback and it didn’t sound good, they had real experiences -- they didn’t make it up...”, is literally saying that he thinks that casual, uncontrolled listening is all about the sound waves. If true, a blind test is completely unnecessary. Being a 100% disproven statement is another minor problem with it. Certainly, the quote above validates my original statement about electrical gurus not being human perception gurus. cheers Grant Link to comment Share on other sites More sharing options...
Guest rmpfyf Posted January 13, 2021 Share Posted January 13, 2021 6 hours ago, Grant Slack said: I’m all in favour of subjective interpretations — validly conducted. You seem to have made an overly simplistic and very incorrect analysis of my view, if you think I am not. As for “both do”, well, it’s just too easy for them to say that, especiallly if they are saying that blind testing has shown audible improvements miles below the established limits of human sensory perception. If that is their claim, then they need to bring their findings into the harsh glare of independent verification. I’m guessing that hasn’t happened? Well then. Why, for example, would Putzeys do blind testing, if he is also willing to make the statement quoted here. “...for those people who say they tried feedback and it didn’t sound good, they had real experiences -- they didn’t make it up...”, is literally saying that he thinks that casual, uncontrolled listening is all about the sound waves. If true, a blind test is completely unnecessary. Being a 100% disproven statement is another minor problem with it. Certainly, the quote above validates my original statement about electrical gurus not being human perception gurus. cheers Grant You've taken some quotes in a very specific context and make some sweeping and incorrect assessments on how others work and think. For instance - didnt state anything regarding your support for subjective testing or otherwise. You seem to assume I have, and that I'm incorrect accordingly. You've too many assumptions. Link to comment Share on other sites More sharing options...
Volunteer sir sanders zingmore Posted January 13, 2021 Volunteer Share Posted January 13, 2021 16 hours ago, frednork said: Pass is on record as using blind tests in amp development, Would be very surprised if Putzeys does not. I’d be surprised if Pass can’t tell his amps apart in a blind test but I agree with one of the earlier posters (@davewantsmoore )that it’s unlikely that the differences he’s hearing are from any special sauce coming from harmonic distortion. He’s almost certainly listening to the way his amps clip. 2 Link to comment Share on other sites More sharing options...
Grizaudio Posted January 13, 2021 Share Posted January 13, 2021 47 minutes ago, sir sanders zingmore said: I’d be surprised if Pass can’t tell his amps apart in a blind test but I agree with one of the earlier posters (@davewantsmoore )that it’s unlikely that the differences he’s hearing are from any special sauce coming from harmonic distortion. He’s almost certainly listening to the way his amps clip. Although I agree, NP amps would clip with certain "nice sounding" characteristics, I 'feel' as a F7 owner it would be quite easy to hear the difference between an F7/J2 and a low distortion Hypex/Purifi operating below clipping. These amplifiers couldn't sound more different from one another. I.e. F7 smooth clipping: In any case I suspect most Firstwatt owners would be partnering their amplifiers with highly sensitive speakers, and therefore would spend very little time in clipping. For instance, with 94-95db sensitive speakers I probably spend most of my time in the 1-5watt window. In regards to harmonic distortion profiles, NP is on record discussing how he manipulates amplifier harmonic distortion profiles to shape amplifier sound. From memory he spoke about distortion and its impact on imaging, perceived smoothness, and listeners preferences for 2nd or 3rd harmonic distortion profiles. There is a couple of good interviews on the Audiophilliac youtube channel where NP briefly discusses distortion, listeners preferences for distortion and his products. This is a great link written by NP. I have linked to page 3, but its worth a total read. https://6moons.com/industryfeatures/distortion/distortion_3.html If you have a moment look through the F7 product pdf. NP explains his amplifier design and its distortion profile. This makes it clear that NP is playing with the distortion profile, to shape his amplifier sound. https://www.firstwatt.com/pdf/prod_f7_man.pdf 1 Link to comment Share on other sites More sharing options...
Ittaku Posted January 13, 2021 Share Posted January 13, 2021 1 hour ago, sir sanders zingmore said: He’s almost certainly listening to the way his amps clip. As we've discussed before More time is spent clipping than people are willing to believe; hence why valves are still so popular. 1 Link to comment Share on other sites More sharing options...
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