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#81
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"Chris Morriss" Patrick Turner The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I do not believe that even PT really believes this! ** Fraid he does. A self taught fool is caught in a positive feedback loop. ............... Phil |
#82
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Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I could ask how much wisdom and astute observation we hear from yourself. Again a hidden lurker ventures from his closit to say about nothing. Good to see you are still alive Chris. I do not believe that even PT really believes this! The above statement you quote could be convey that I was preaching gospel, but I wasn't. Plenty of ppl say the total phase of the signal must not be altered between microphone and speaker. I don't believe that if you reverse the phase you will hear any sound change. But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. In fact it was fashionable to have phase reverse switch positions on the swith devoted to stereo/mono. More do-dahs for ppl to play with, more BS for salesmen to yabber on about. More features, more sales. Audiophiles have negligible thd in their replay systems, so changing phase is a useless option with yet another damned switch in the signal path. And of course they want their music's phase kept the same as heard by the microphone please. Otherwise, they are compelled to listen facing away from their speakers, or with their speakers upside down, or only while attempting upside down yoga positions. Basically, when a suck signal arrives, it must not arrive as a blow. Similarly, a blow signal arrives, it must not turn out to be a suck. And the knowledge that a suck might be a blow, or a blow might be a suck, is an excruciating uncertainty. They are not always calmed by informing them that after a suck a blow follows, followed by another suck, then another blow, in successive waves, milliseconds apart. Patrick Turner. -- Chris Morriss |
#83
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snip fulminant logorrhea
Hear, hear. And not to forget social climbing in a pink coat, trying to buy his way into the mounted classes. Pinko Presumptuous indeed. Andre Jute That explains a lot, Andre. I always suspected you were one of the MOUNTED CLASSES. What's it like to be on the receiving end, old chap? |
#84
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In message , Patrick Turner
writes Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I could ask how much wisdom and astute observation we hear from yourself. Again a hidden lurker ventures from his closit to say about nothing. Good to see you are still alive Chris. I do not believe that even PT really believes this! The above statement you quote could be convey that I was preaching gospel, but I wasn't. Plenty of ppl say the total phase of the signal must not be altered between microphone and speaker. I don't believe that if you reverse the phase you will hear any sound change. But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. (Much snipped) Now pay attention. What you are really saying is that if you feed an amplifier with a signal containing harmonics (ie, music for example), then depending on whether the amp is inverting or non-inverting, the structure of the harmonics present at the amp output will change. Come on, don't be so silly. -- Chris Morriss |
#85
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Jon Yaeger wrote: snip fulminant logorrhea Hear, hear. And not to forget social climbing in a pink coat, trying to buy his way into the mounted classes. Pinko Presumptuous indeed. Andre Jute That explains a lot, Andre. I always suspected you were one of the MOUNTED CLASSES. What's it like to be on the receiving end, old chap? Hello Jon- It is clear you never saw Andre play polo. You wouldn't be in any doubt about who was on the receiving end. Best, Gray |
#87
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On 24 Mar 2005 23:58:48 -0800, "
wrote: The commies would have taken over and the natives would be in the gulag or kneeling on the rubber mat for the bullet in the back of the neck. More your style surely, sad sack? Hear, hear. And not to forget social climbing in a pink coat, trying to buy his way into the mounted classes. Pinko Presumptuous indeed. Never worn a pink coat in my life, you pathetic stalker. OTOH, those who know me through e-mail are aware that social climbing is unlikely to be a priority, except perhaps for others................. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#88
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#89
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On Sat, 26 Mar 2005 00:29:03 +1100, Patrick Turner
wrote: Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I could ask how much wisdom and astute observation we hear from yourself. Again a hidden lurker ventures from his closit to say about nothing. Good to see you are still alive Chris. I do not believe that even PT really believes this! The above statement you quote could be convey that I was preaching gospel, but I wasn't. Plenty of ppl say the total phase of the signal must not be altered between microphone and speaker. I don't believe that if you reverse the phase you will hear any sound change. And if you did, anyone but a clown like you would know that you simply reverse the speaker terminals to regain absolute phase........... But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. Turner, you're an idiot, and this is the final nail in the coffin. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#90
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On Fri, 25 Mar 2005 23:03:04 +1100, Patrick Turner
wrote: Stewart Pinkerton wrote: On Fri, 25 Mar 2005 17:08:54 +1100, Patrick Turner wrote: The open loop thd of pinky's amp is very high. But he uses 3 loops to reduce it, EF connection on the buffer input, current FB in the gain stage, and EF connected outputs, so a total of perhaps 150 dB of NFB is applied. None of these are loops, as you well know, so your argument is bogus. The shallow state of your bogus understanding of electronic engineering is becoming all too apparent. Turner, you're a tubecentric clown who will use any argument to 'prove' that tubes are better. It won't wash. Pinky said he wanted to avoid the magic of the 300B. We will of course let him. No, I said that the 'magic' of the 300B is mythical, which KISASS and other simple SS designs can prove. PPlease don't stoop to flat lies in your desperate defence of tubes. In the case of his rather illconcieved SS amp, More pathetic jealousy from Turner. If one uses a single tube for a cathode follower, and a gain reduction due to the FB was sat 10 times, or 20 dB, then it is the same as having a multi stage amp and applying 20 dB of NFB, as in a Williamson. No, it's absolutely *not* the same, as any professional engineer will tell you. Its no use tellin pinky that a single loop of NFB could have been used which would also render his amp being non-inverting, like all good amps are. It's no use tellin Turner that many classic hi-fi amps are inverting, the Quad 405 being but one example. And it's no use tellin Turner that zero loop feedback is fundamental to KISASS. Most amps I have ever worked on are non inverting. So what? Its not a problem to me, but to many folks an inverting power amp is just not right. I routinely use a single triode for a preamp, and of course the signal is inverted. Well reverse the speaker terminals. Sheesh, whatta maroon! The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Turner, you're an idiot, and that's the final nail in the coffin. As I explained above, loop FB includes short loops. Global loop FB usually means a loop around several stages, such as in Williamson's amp, and the not so wonderful JLH replacement. As I recall, JLH didn't want to have to build another identical tube amp to make two channels for stereo, and took the lazy man's avenue, and went all solid state. It explains why there are so many old single tube monoblock amps around. Shows to what depths you'll stoop, when you have to attack a truly classic amplifier and its designer. You and Jute are a well-matched pair of bitter old failures, arent you? It's no wonder your women walked out on you........................ -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#91
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In article , Stewart Pinkerton
wrote: On Thu, 24 Mar 2005 11:01:53 -0600, (John Byrns) wrote: In article , Stewart Pinkerton wrote: You just don't get it, do you? If you want to build an *optimum* 'KISASS', just use the Linsley Hood design from 1969. How do you figure the 1969 JLH design is "optimum"? It looks to me like your "KISASS" design is at least as "optimum" as the JLH design. I would think a more optimum design would be a combination of the two designs, taking the best features of each. I designed KISASS according to the basic pre-conditions of a basically single-ended transfer function, less than 10 watts output into any reasonable speaker load, and no loop NFB. It was never intended to be an 'optimal' design, except within those constraints. If you read my question carefully you will se that I was not asking about your "KISASS" amplifier, but was actually asking why you say the 1969 JLH design is "optimum"? What I said about your design was that it is my feeling that it is more nearly "optimum" than the 1969 JLH design. Regards, John Byrns Surf my web pages at, http://users.rcn.com/jbyrns/ |
#92
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In article , Stewart Pinkerton
wrote: On Thu, 24 Mar 2005 22:04:50 +1100, Patrick Turner wrote: The designer is well-known *because* of that amplifier, which was a landmark design. But JLH already had a big profile at Wireless World, so it wasn't difficult for him to gild it further with a class A SS design. Utter ********. Show evidence of a 'big profile' prior to 1969. You're just a typical whining aussie who's jealous of a *real* innovator. While I can't back it up immediately, however I will work on it, I have the vague feeling that I recently stumbled across several articles by JLH in some 1950's issues of Wireless World, possibly even articles on tube/valve amplifiers. Are you saying that JLH was not writing articles for Wireless World before his 1969 article? Also JLH's design doesn't even seem state of the art for 1969. Regards, John Byrns Surf my web pages at, http://users.rcn.com/jbyrns/ |
#93
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Chris Morriss wrote: In message , Patrick Turner writes Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I could ask how much wisdom and astute observation we hear from yourself. Again a hidden lurker ventures from his closit to say about nothing. Good to see you are still alive Chris. I do not believe that even PT really believes this! The above statement you quote could be convey that I was preaching gospel, but I wasn't. Plenty of ppl say the total phase of the signal must not be altered between microphone and speaker. I don't believe that if you reverse the phase you will hear any sound change. But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. (Much snipped) Now pay attention. What you are really saying is that if you feed an amplifier with a signal containing harmonics (ie, music for example), then depending on whether the amp is inverting or non-inverting, the structure of the harmonics present at the amp output will change. In all 2 stage SET amps where a triode driver tube creates its own 2H, this 2H tends to cancel the 2H produced in the output triode. Now the amount of cancellation isn't perfect, and depends on the gain of the output tube and the rate of increase of 2H for the tubes concerned. In a recently built pair of SE35 amp with 6CA7 with CFB and driven by EL84 in triode, the mainly 2H in the amplifier when 5.5 ohms is used for the RL is almost nulled right away to zero, leaving only 3H and other lesser quantity harmonics at a THD level 20 dB below what it would be if the amp had a perfectly linear driver tube. There is very useful 2H cancellation below 5.5 ohms, and as the phase of the 2H from the tetrode output reverses abobe a certain load value, the driver 2H then begins to become additive to the 2H, but fortunately, the adding effect is far less than the cancelation effect. Suppose we consider somebody making a signal with an oboe, whatever, and creating a potpourrie of harmonics of the fundemental. A few of them will be even order, and some odd order, and of various phase relationships to the fundemental. Consider that the replay system also produces a pile of harmonics **of the fundemental and all other F present** Now it must be obvious that lady luck will permit some cancellation or reinforcement of the harmonics in the source signal as it passes through the replay system. The amount this occurs depends on the phase relationships and the amplitudes of the harmonics concerrned, and will vary depending on whether the phase is either at 0 degrees, or at 180 degrees. To deny there is any difference in the outcome is silly. The possibility for 2H cancellation or reinforcement with an SET amp is quite substantial, and if a speaker produces say 0.1 % of 2H and so does the amp, and the phasing permits, then good cancellation is possible. Similarly if the microphone, recording amp, cutting head amp and vinyl also instal their harmonics, and even if a singer's voice has 2H, these harmonics do indeed interact with the following record/replay systems. Musical tones sometimes have 2H and 3H levels above the amplitude of the fundemental, and so the harmonic cancellation or reinforcement of a fraction of a percent won't have much effect. So even if an amp has appalling thd, the oboe will still sound like an oboe regardless of what we do with the phase of the input signal. These days microphones may be linear, and amplifiers, and the digital realm removes most thd, so the result at the CD player is maybe more faithful than ever before, ( but don't ask me why so many old analog recordings sound so good ). So we are left mainly with the harmonics of the music itself. This harmonic relationship is slightly altered by any electronics or transducers. Distortion of the harmonics and IMD all still occurs as usual, and the 2H produced by a driver tube feeding an output triode is amplified and a small amount of 4H is produced. Also 3H and more fundemental, since there are sum and difference F produced by imd mechanisms. I doubt any of this matters much if the enthusiast has taken steps to build his gear with sufficient power ceiling to operate with negligible thd. This usually is the case with an SET amp and of course the thd is mainly a forgivable amount of 2H. Fiddling with signal phase, even speaker phase connection allows us to modify the harmonics at the ear. I myself never worry about the absolute phase and a phase inverting amp doesn't worry me, because all my gear is linear enough. Patrick Turner. Come on, don't be so silly. -- Chris Morriss |
#94
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Stewart Pinkerton wrote: On Sat, 26 Mar 2005 00:29:03 +1100, Patrick Turner wrote: Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I could ask how much wisdom and astute observation we hear from yourself. Again a hidden lurker ventures from his closit to say about nothing. Good to see you are still alive Chris. I do not believe that even PT really believes this! The above statement you quote could be convey that I was preaching gospel, but I wasn't. Plenty of ppl say the total phase of the signal must not be altered between microphone and speaker. I don't believe that if you reverse the phase you will hear any sound change. And if you did, anyone but a clown like you would know that you simply reverse the speaker terminals to regain absolute phase........... Sure, we all know that. But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. Turner, you're an idiot, and this is the final nail in the coffin. Unfortunately, you fail to read the meaning of what I said. I'll have to repeat it :- But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. This happens, but pinky can't see that it does. And in fact there is odd order cancelation and additions as well, since the phase of musical harmonics is related to the fundemental over a wide range of angles. Patrick Turner. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#95
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Temper, temper, both of you.
It is true that not many people can detect inverted phase in the result, the music, but it also true that to those who can detect phase it is a big deal, ruining the experience. It is further regrettably true that both the mechanism for detecting phase (more precisely out-of-phase) and the mechanism by which it irritates so disproportionately are very poorly understood. Andre Jute Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I do not believe that even PT really believes this! -- Chris Morriss |
#96
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On Fri, 25 Mar 2005 15:51:32 -0600, (John Byrns) wrote:
In article , Stewart Pinkerton wrote: On Thu, 24 Mar 2005 11:01:53 -0600, (John Byrns) wrote: In article , Stewart Pinkerton wrote: You just don't get it, do you? If you want to build an *optimum* 'KISASS', just use the Linsley Hood design from 1969. How do you figure the 1969 JLH design is "optimum"? It looks to me like your "KISASS" design is at least as "optimum" as the JLH design. I would think a more optimum design would be a combination of the two designs, taking the best features of each. I designed KISASS according to the basic pre-conditions of a basically single-ended transfer function, less than 10 watts output into any reasonable speaker load, and no loop NFB. It was never intended to be an 'optimal' design, except within those constraints. If you read my question carefully you will se that I was not asking about your "KISASS" amplifier, but was actually asking why you say the 1969 JLH design is "optimum"? What I said about your design was that it is my feeling that it is more nearly "optimum" than the 1969 JLH design. Ah, OK. I believe the JLH design to be optimum because it is even simpler than KISASS in actual component count, and it uses its active devices in a more appropriate way (for SS technology) to provide less than 0.1% distortion (mostly 2nd harmonic) across the audio band at ten watts output. Being a Class A design, that low distortion reduces linearly with decreasing output level, being essentially unmeasureable at 1 watt or below. KISASS has quite different design constraints, and is intended to follow the unlikely phlosophy that loop NFB is evil, as is symmetrical push-pull operation, and that it's only linearity below 1 watt that matters for 'ultra fidelity'. Regarding push-pull operation, the output emitter followers are of course arranged in push-pull, but the distortion levels of output and input EFs are so tiny that the amplifier transfer curve is totally dominated by the central gain stage - which is the essence of the design. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#97
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On 25 Mar 2005 17:11:48 -0800, "
wrote: It is true that not many people can detect inverted phase in the result, the music, but it also true that to those who can detect phase it is a big deal, ruining the experience. It is further regrettably true that both the mechanism for detecting phase (more precisely out-of-phase) and the mechanism by which it irritates so disproportionately are very poorly understood. What is well understood however, is that not one person has *ever* been able to demonstrate a reliable and repeatable ability to hear absolute phase - when they did not *know* what was connected. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#98
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On Fri, 25 Mar 2005 15:55:09 -0600, (John Byrns) wrote:
In article , Stewart Pinkerton wrote: On Thu, 24 Mar 2005 22:04:50 +1100, Patrick Turner wrote: The designer is well-known *because* of that amplifier, which was a landmark design. But JLH already had a big profile at Wireless World, so it wasn't difficult for him to gild it further with a class A SS design. Utter ********. Show evidence of a 'big profile' prior to 1969. You're just a typical whining aussie who's jealous of a *real* innovator. In case of doubt, I'm referring here to Turner. :-) While I can't back it up immediately, however I will work on it, I have the vague feeling that I recently stumbled across several articles by JLH in some 1950's issues of Wireless World, possibly even articles on tube/valve amplifiers. Are you saying that JLH was not writing articles for Wireless World before his 1969 article? Also JLH's design doesn't even seem state of the art for 1969. AFAIK, the 1969 article was his debut. This link may help: http://www.tcaas.btinternet.co.uk/jlharticles.htm Whatever Turner may think, surrounded by the ruins of his sad and solitary life, and snarling viciously from his little radio repair shack in the boonies of Oz, many serious audiophiles (and professional engineers) regard the late, great John Linsley Hood as one of the finest audio designers of his generation. Unlike many 'high end' dabblers such as Peter Qvortrup, JLH never claimed anything for his designs which was not backed by measurements and solid science, and he was more modest than many of greatly lesser ability in the sudio world. His books remain classic texts for those with a real interest in high-fidelity music reproduction, and some would claim that, if ten watts are enough to drive your speakers, you will still not find a better-sounding amplifier than his original 1969 design. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#99
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In message , Patrick Turner
writes Chris Morriss wrote: In message , Patrick Turner writes Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I could ask how much wisdom and astute observation we hear from yourself. Again a hidden lurker ventures from his closit to say about nothing. Good to see you are still alive Chris. I do not believe that even PT really believes this! The above statement you quote could be convey that I was preaching gospel, but I wasn't. Plenty of ppl say the total phase of the signal must not be altered between microphone and speaker. I don't believe that if you reverse the phase you will hear any sound change. But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. (Much snipped) Now pay attention. What you are really saying is that if you feed an amplifier with a signal containing harmonics (ie, music for example), then depending on whether the amp is inverting or non-inverting, the structure of the harmonics present at the amp output will change. In all 2 stage SET amps where a triode driver tube creates its own 2H, this 2H tends to cancel the 2H produced in the output triode. Now the amount of cancellation isn't perfect, and depends on the gain of the output tube and the rate of increase of 2H for the tubes concerned. Yes yes of course, but that's not what you said! Correcting one non-linear transfer function by following it with another equal and opposite non-linearity is perfectly sensible, as it's the same signal passing through both stages, but that *is not* what you said. You said that inverting and non-inverting amps have different effects upon external signals being fed to the amps. This is utter rubbish as you know well. I'll give you the benefit of the doubt that this was simply a slip of your pen due to the local 12% alcohol Shiraz! -- Chris Morriss |
#100
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In message , Patrick Turner
writes Unfortunately, you fail to read the meaning of what I said. I'll have to repeat it :- But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. This happens, but pinky can't see that it does. And in fact there is odd order cancelation and additions as well, since the phase of musical harmonics is related to the fundemental over a wide range of angles. Patrick Turner. My power amp has balance XLR inputs, which I feed from a single-ended source by grounding the 'cold' input at the pre-amp. I can just as easily ground the 'hot' input instead, making the PA inverting. Now please tell me by what occult means the PA will alter the harmonics of the signal passing through the amp, depending on whether I drive it inverting or non inverting. Or to make another simpler analogy. If I precede an inverting PA with an inverting buffer stage, will the even harmonic distortion of the whole drop?? I DON'T THINK SO. -- Chris Morriss |
#101
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In message .com,
" writes Temper, temper, both of you. It is true that not many people can detect inverted phase in the result, the music, but it also true that to those who can detect phase it is a big deal, ruining the experience. It is further regrettably true that both the mechanism for detecting phase (more precisely out-of-phase) and the mechanism by which it irritates so disproportionately are very poorly understood. Andre Jute No Andre, this isn't what I'm complaining about. I believe there is some evidence, that on some signals, then absolute phase might be audible, so I won't argue against this point. I'm complaining about Patrick's occult distortion mechanism in an inverting amp when fed with a signal containing harmonics! -- Chris Morriss |
#102
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On Sat, 26 Mar 2005 09:55:09 +0000, Chris Morriss
wrote: In message , Patrick Turner writes Unfortunately, you fail to read the meaning of what I said. I'll have to repeat it :- But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. This happens, but pinky can't see that it does. And in fact there is odd order cancelation and additions as well, since the phase of musical harmonics is related to the fundemental over a wide range of angles. Patrick Turner. My power amp has balance XLR inputs, which I feed from a single-ended source by grounding the 'cold' input at the pre-amp. I can just as easily ground the 'hot' input instead, making the PA inverting. Now please tell me by what occult means the PA will alter the harmonics of the signal passing through the amp, depending on whether I drive it inverting or non inverting. Or to make another simpler analogy. If I precede an inverting PA with an inverting buffer stage, will the even harmonic distortion of the whole drop?? I DON'T THINK SO. Don't badger the pooor old duffer - he has trouble remembering where the loo is these days, never mind what happens inside them new-fangled amplifier thingies! :-) -- Stewart Pinkerton | Music is Art - Audio is Engineering |
#103
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" wrote: Temper, temper, both of you. It is true that not many people can detect inverted phase in the result, the music, but it also true that to those who can detect phase it is a big deal, ruining the experience. It is further regrettably true that both the mechanism for detecting phase (more precisely out-of-phase) and the mechanism by which it irritates so disproportionately are very poorly understood. Andre Jute I would also add that there would be an optimal phase connection to get a maximal amount of harmonic distortion cancellation between source and preamp, preamp and power amp, and power amp and speakers. However, finding the optimal phase arrangements would be tortuous, and only offer perhaps marginal sonic improvements if any. Motzartian test signals are indeed a complex brew. Its not an issue I lose sleep over, but some do. Patrick Turner. Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I do not believe that even PT really believes this! -- Chris Morriss |
#104
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Stewart Pinkerton wrote: On Fri, 25 Mar 2005 15:51:32 -0600, (John Byrns) wrote: In article , Stewart Pinkerton wrote: On Thu, 24 Mar 2005 11:01:53 -0600, (John Byrns) wrote: In article , Stewart Pinkerton wrote: You just don't get it, do you? If you want to build an *optimum* 'KISASS', just use the Linsley Hood design from 1969. How do you figure the 1969 JLH design is "optimum"? It looks to me like your "KISASS" design is at least as "optimum" as the JLH design. I would think a more optimum design would be a combination of the two designs, taking the best features of each. I designed KISASS according to the basic pre-conditions of a basically single-ended transfer function, less than 10 watts output into any reasonable speaker load, and no loop NFB. It was never intended to be an 'optimal' design, except within those constraints. If you read my question carefully you will se that I was not asking about your "KISASS" amplifier, but was actually asking why you say the 1969 JLH design is "optimum"? What I said about your design was that it is my feeling that it is more nearly "optimum" than the 1969 JLH design. Ah, OK. I believe the JLH design to be optimum because it is even simpler than KISASS in actual component count, and it uses its active devices in a more appropriate way (for SS technology) to provide less than 0.1% distortion (mostly 2nd harmonic) across the audio band at ten watts output. Being a Class A design, that low distortion reduces linearly with decreasing output level, being essentially unmeasureable at 1 watt or below. KISASS has quite different design constraints, and is intended to follow the unlikely phlosophy that loop NFB is evil, as is symmetrical push-pull operation, and that it's only linearity below 1 watt that matters for 'ultra fidelity'. Regarding push-pull operation, the output emitter followers are of course arranged in push-pull, but the distortion levels of output and input EFs are so tiny that the amplifier transfer curve is totally dominated by the central gain stage - which is the essence of the design. -- But you use an enormous amount of NFB in 3 loops in kissass. It upends the correctness of anything you say. And you don't wanna build or test anything. Patrick Turner Stewart Pinkerton | Music is Art - Audio is Engineering |
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Chris Morriss wrote: In message , Patrick Turner writes Chris Morriss wrote: In message , Patrick Turner writes Chris Morriss wrote: In message , Patrick Turner writes The detectability of inverted signals isn't all that great. But if a source signal does have significant even order harmonics, then the phase of those harmonics may either cancel or reinforce those in the amp chain or the speakers. Dear God, how much more nonsense do we have to put up with from this man? I could ask how much wisdom and astute observation we hear from yourself. Again a hidden lurker ventures from his closit to say about nothing. Good to see you are still alive Chris. I do not believe that even PT really believes this! The above statement you quote could be convey that I was preaching gospel, but I wasn't. Plenty of ppl say the total phase of the signal must not be altered between microphone and speaker. I don't believe that if you reverse the phase you will hear any sound change. But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. (Much snipped) Now pay attention. What you are really saying is that if you feed an amplifier with a signal containing harmonics (ie, music for example), then depending on whether the amp is inverting or non-inverting, the structure of the harmonics present at the amp output will change. In all 2 stage SET amps where a triode driver tube creates its own 2H, this 2H tends to cancel the 2H produced in the output triode. Now the amount of cancellation isn't perfect, and depends on the gain of the output tube and the rate of increase of 2H for the tubes concerned. Yes yes of course, but that's not what you said! Correcting one non-linear transfer function by following it with another equal and opposite non-linearity is perfectly sensible, as it's the same signal passing through both stages, but that *is not* what you said. You said that inverting and non-inverting amps have different effects upon external signals being fed to the amps. I think you didn't get me right. I thought I made it clear that the harmonics of music, or those of a recording system will tend to cancel or add to the thd of a replay system. Certainly if there was 2H imposed by a recording studio's gear to the extent of 0.1%, then when applied to a replay amp with 0.1%, 2H, we could expect the amp to stay the same unchanging happy little amp it always was, but at the output there would be either no 2H, or 0.2%, depending on the phase of the 2H. I do not believe I said the transfer function on a replay system would be altered by the harmonics of the input signal. The transfer curves of either of the 2 cascaded triodes in an SET design do not change any transfer curves, but there is a lowering of thd due to cancellation. This is utter rubbish as you know well. I'll give you the benefit of the doubt that this was simply a slip of your pen due to the local 12% alcohol Shiraz! I am not a heavy boozer at all. But yeah, the local wineries make a drinkable drop, to be sure now. Patrick Turner. -- Chris Morriss |
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Chris Morriss wrote: In message , Patrick Turner writes Unfortunately, you fail to read the meaning of what I said. I'll have to repeat it :- But speakers and amps do generate even order harmonics, and I repeat that if the audio source has even order harmonics, they will try to either cancel or add to the replay system's even H. So depending which phase one chooses, the thd at the speaker will vary. This happens, but pinky can't see that it does. And in fact there is odd order cancelation and additions as well, since the phase of musical harmonics is related to the fundemental over a wide range of angles. Patrick Turner. My power amp has balance XLR inputs, which I feed from a single-ended source by grounding the 'cold' input at the pre-amp. I can just as easily ground the 'hot' input instead, making the PA inverting. Now please tell me by what occult means the PA will alter the harmonics of the signal passing through the amp, depending on whether I drive it inverting or non inverting. I have already explained the simple idea of harmonic cancelation between an SET driver tube powering an SET output tube. There is no occult funny business going on. Or to make another simpler analogy. If I precede an inverting PA with an inverting buffer stage, will the even harmonic distortion of the whole drop?? I DON'T THINK SO. Perhaps it will, depending on the amount of 2H. You must look a little deeper. 2H currents are developed in all output tubes. With two equal tubes in a PP circuit, most of the 2H currents cancel each other, and this is 2H **current** cancelation. You can have 2H **voltage** cancelation between cascaded stages. if there is 2H in the input source signal, it may or may not be cancelled by the input stages 2H. Its actually unlikely, due to phase and amplitudes being unlikely to occur which woukd lead to much thd cancelation. But in an SE35, I get a shirtful of 2H cancelation between driver and stages in the critical load region of 4.5 to 6 ohms; and its done even though I have set up the tubes to operate with optimal loadings. I cannot damn well avoid the voltage cancelation. Transfer curves stay the same for each stage, harmonics cancel, thd is as low as for a good PP amp for the same low amount of total applied NFB. Have I made myself as clear to you as you would wish? Happy Easter, Patrick Turner. -- Chris Morriss |
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Chris Morriss wrote: In message .com, " writes Temper, temper, both of you. It is true that not many people can detect inverted phase in the result, the music, but it also true that to those who can detect phase it is a big deal, ruining the experience. It is further regrettably true that both the mechanism for detecting phase (more precisely out-of-phase) and the mechanism by which it irritates so disproportionately are very poorly understood. Andre Jute No Andre, this isn't what I'm complaining about. I believe there is some evidence, that on some signals, then absolute phase might be audible, so I won't argue against this point. I'm complaining about Patrick's occult distortion mechanism in an inverting amp when fed with a signal containing harmonics! Easter is a time when people celebrate a guy dying on a cross, and rising from the dead on the third day. The mind wanders. I doubt Christ died on a cross or rose from the dead. Interpreters of the scripts find a lot to argue about now. And for thinking and talking heretically, and in public, it now doesn't bring a crew of hooded monks around to cart you off to firewood and fire. But He did teach us that through pain we must travel, and we will rise again, since the Bible is mostly parabolic, rather than linearly literal. I don't know where I'll rise to if I am so pained I die. But sure, if a dude trips me up and I fall, I must rise from the pavement. Sometimes, if the dude is smaller than me, I might catch up to him, and ask " WTF you do that for, huh?" What would He have done? I reckon pain just teaches us that pain is painful, most of the time. You cannot change an amps transfer curve, but the source signal phase may make a change to the amplifier harmonic distortion outcome. Patrick Turner. -- Chris Morriss |
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In message , Patrick Turner
writes I think you didn't get me right. I thought I made it clear that the harmonics of music, or those of a recording system will tend to cancel or add to the thd of a replay system. Certainly if there was 2H imposed by a recording studio's gear to the extent of 0.1%, then when applied to a replay amp with 0.1%, 2H, we could expect the amp to stay the same unchanging happy little amp it always was, but at the output there would be either no 2H, or 0.2%, depending on the phase of the 2H. And what has this to do with inverting or non-inverting configurations? -- Chris Morriss |
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In message , Patrick Turner
writes I think you didn't get me right. I thought I made it clear that the harmonics of music, or those of a recording system will tend to cancel or add to the thd of a replay system. Certainly if there was 2H imposed by a recording studio's gear to the extent of 0.1%, then when applied to a replay amp with 0.1%, 2H, we could expect the amp to stay the same unchanging happy little amp it always was, but at the output there would be either no 2H, or 0.2%, depending on the phase of the 2H. I do not believe I said the transfer function on a replay system would be altered by the harmonics of the input signal. The transfer curves of either of the 2 cascaded triodes in an SET design do not change any transfer curves, but there is a lowering of thd due to cancellation. Therefore the transfer function of two triode stages which are connected so that the second stage has an equal and opposite non-linearity compared with the first stage *WILL* change the transfer function of the two stages together, in the ideal case, making it completely linear. Not a trivial thing to arrange of course :-) In this case, the signal passing through the second stage is HIGHLY correlated with the signal passing through the first stage. (Not surprisingly!) I take issue with your extrapolation of this specific case into one where the amplifier is handling an external music signal with many fundamental and harmonic frequencies at any one time. The non-linearity of the amplifier cannot have any correlation with the cause of the non-linearities in the recording chain (and in the instruments themselves) which produced the complex signal being fed to the amplifier. Your dogmatic assertion that inverting the phase of the input signal to an amplifier alters the THD at the output is erroneous, (although I can see how you might think this could come about, in a singled-ended amplifier at least, where even-harmonic distortion components should be dominant). -- Chris Morriss |
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Chris Morriss wrote: In message , Patrick Turner writes I think you didn't get me right. I thought I made it clear that the harmonics of music, or those of a recording system will tend to cancel or add to the thd of a replay system. Certainly if there was 2H imposed by a recording studio's gear to the extent of 0.1%, then when applied to a replay amp with 0.1%, 2H, we could expect the amp to stay the same unchanging happy little amp it always was, but at the output there would be either no 2H, or 0.2%, depending on the phase of the 2H. I do not believe I said the transfer function on a replay system would be altered by the harmonics of the input signal. The transfer curves of either of the 2 cascaded triodes in an SET design do not change any transfer curves, but there is a lowering of thd due to cancellation. Therefore the transfer function of two triode stages which are connected so that the second stage has an equal and opposite non-linearity compared with the first stage *WILL* change the transfer function of the two stages together, in the ideal case, making it completely linear. Not a trivial thing to arrange of course :-) Yes, exactly. However, it is of little great value since the load value of speakers changes around a centre nominal value all the time. With a tetrode/pentode output stage, there is a certain load value where 2H falls to zero, and thd is mainly odd order. below this RL, 2H is phased like that of a triode, and above the critical RL 2H is oppositely phased. The critical RL might be 8 ohms for a given beam/pentode. So a triode driver will have a 2H which is only tending to cancel below the critical RL. Above the critical RL, 2H becomes additive. The 2H of a driver tube does cause useful 2H cancellation, but only for a range of output load values. The driver 2H also is distorted by the output tube to make second order 4H, and maybe that cancels any 4H in the output. 3H and more fundemental are produced by imd. Its all very complex. But local 12.5% of CFB allows max 2H between 3 and 12 ohms to remain below 1.5% at full power. This is a huge reduction from the ugly profile of pure beam/pentode, where open loop thd can be 13% at full power, and worst when RL is 12 ohms, compared to 3 ohms. In this case, the signal passing through the second stage is HIGHLY correlated with the signal passing through the first stage. (Not surprisingly!) Yes, but subject to load conditions of the output tube... I take issue with your extrapolation of this specific case into one where the amplifier is handling an external music signal with many fundamental and harmonic frequencies at any one time. The non-linearity of the amplifier cannot have any correlation with the cause of the non-linearities in the recording chain (and in the instruments themselves) which produced the complex signal being fed to the amplifier. Yes but don't you see that some 2H of the amplifier may well cancel 2H in the music? The harmonics relative amplitudes get altered by the amplifier's natural transfer curve. Usually steps are taken to minimise this, since we don't want a recording of a fine old italian violin to sound like a cheap Suzuki trainer. Your dogmatic assertion that inverting the phase of the input signal to an amplifier alters the THD at the output is erroneous, (although I can see how you might think this could come about, in a singled-ended amplifier at least, where even-harmonic distortion components should be dominant). There may be harmonic distortion in the source signal from the studio electronics. These may or may not cancel the distortion in the replay amp, depending on phase, as well as amplitudes involved. In which case although the amp does not change its transfer curve, the harmonic outcome is more/less, better/worse. If you have 100 cascaded amplifiers, each with 0.1% thd, you do awful things to the music. Its very difficult to arrange they all cancell each other's thd. but if you have 0.001%, 100 amps could be cascaded, and thd would remain low regardless of cancellations or phase applied. Modern electronics with high NFB allowed many cascaded amps with no alterations to the sound, ( in theory ) How many opamps are there on a large analog mixing desk? They were not used for long before digital swept away analog. Patrick Turner. -- Chris Morriss |
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In article , Stewart Pinkerton
wrote: On Fri, 25 Mar 2005 15:51:32 -0600, (John Byrns) wrote: In article , Stewart Pinkerton wrote: On Thu, 24 Mar 2005 11:01:53 -0600, (John Byrns) wrote: In article , Stewart Pinkerton wrote: You just don't get it, do you? If you want to build an *optimum* 'KISASS', just use the Linsley Hood design from 1969. How do you figure the 1969 JLH design is "optimum"? It looks to me like your "KISASS" design is at least as "optimum" as the JLH design. I would think a more optimum design would be a combination of the two designs, taking the best features of each. I designed KISASS according to the basic pre-conditions of a basically single-ended transfer function, less than 10 watts output into any reasonable speaker load, and no loop NFB. It was never intended to be an 'optimal' design, except within those constraints. If you read my question carefully you will se that I was not asking about your "KISASS" amplifier, but was actually asking why you say the 1969 JLH design is "optimum"? What I said about your design was that it is my feeling that it is more nearly "optimum" than the 1969 JLH design. Ah, OK. I believe the JLH design to be optimum because it is even simpler than KISASS in actual component count, and it uses its active devices in a more appropriate way (for SS technology) to provide less than 0.1% distortion (mostly 2nd harmonic) across the audio band at ten watts output. Being a Class A design, that low distortion reduces linearly with decreasing output level, being essentially unmeasureable at 1 watt or below. While the JLH 1969 amplifier may have distortion below 0.1%, I suspect that distortion number is achieved mainly with NFB, and if the open loop distortion were measured, it would be considerably greater than in your design. The JLH design doesn't even look "optimum" in the context of 1969. I would think a more nearly "optimum" design would be to graft the first two stages of the JLH design onto your output stage, eliminating the distortion produced by JLH's odd output stage. Regards, John Byrns Surf my web pages at, http://users.rcn.com/jbyrns/ |
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WE OFTEN HEAR IT SAID DISPARAGINGLY that some writer or other is a mere
"escapist," or that a particular piece of writing is sheer "escapism." It is implied that the true function of literature is, not to offer escape from unpleasant facts, but to help the reader to face up to reality, and cope with it successfully. On the other hand we are told by many of those who are interested in the theory of art that the proper function of all art, and therefore of literature, is "cathartic," that it should purge the spirit of pent-up forces which cannot express themselves in actual life, that it should afford symbolic fulfilment to our starved needs. Through art these pent-up forces are said to obtain "release." Sometimes it is claimed that, by diverting attention from the sordid actuality, art constructs symbols of a deeper reality, more consonant with the spirit=92s real needs.(Stapledon, 1939) |
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On Sat, 26 Mar 2005 23:17:58 +1100, Patrick Turner
wrote: KISASS has quite different design constraints, and is intended to follow the unlikely phlosophy that loop NFB is evil, as is symmetrical push-pull operation, and that it's only linearity below 1 watt that matters for 'ultra fidelity'. Regarding push-pull operation, the output emitter followers are of course arranged in push-pull, but the distortion levels of output and input EFs are so tiny that the amplifier transfer curve is totally dominated by the central gain stage - which is the essence of the design. -- But you use an enormous amount of NFB in 3 loops in kissass. It upends the correctness of anything you say. Cut the crap Turner, no one but you believes that these are any kind of loops. And KISSASS isn't my design. And you don't wanna build or test anything. Not KISASS, as already stated. And certainly not KISS, should Jute ever get around to actually creating it as a finished design, rather than generating endless attack threads. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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Stewart Pinkerton wrote: On Sat, 26 Mar 2005 23:17:58 +1100, Patrick Turner wrote: KISASS has quite different design constraints, and is intended to follow the unlikely phlosophy that loop NFB is evil, as is symmetrical push-pull operation, and that it's only linearity below 1 watt that matters for 'ultra fidelity'. Regarding push-pull operation, the output emitter followers are of course arranged in push-pull, but the distortion levels of output and input EFs are so tiny that the amplifier transfer curve is totally dominated by the central gain stage - which is the essence of the design. -- But you use an enormous amount of NFB in 3 loops in kissass. It upends the correctness of anything you say. Cut the crap Turner, no one but you believes that these are any kind of loops. And KISSASS isn't my design. I'll cut you a nice slice of crap, and serve it up to you when I see fit. Bon apertite. So whose design was KISSASS? Santa Claws? And you don't wanna build or test anything. Not KISASS, as already stated. Your'e looking worse and worse and more irelevant day by day.... And certainly not KISS, should Jute ever get around to actually creating it as a finished design, rather than generating endless attack threads. But why should he hurry? Rome wasn't built in a day. And you attract such a lot of flack, so don't complain. Patrick Turner. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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Stewart Pinkerton wrote: On Sat, 26 Mar 2005 17:20:28 -0600, (John Byrns) wrote: While the JLH 1969 amplifier may have distortion below 0.1%, I suspect that distortion number is achieved mainly with NFB, and if the open loop distortion were measured, it would be considerably greater than in your design. Well of course, because the JLH amp is *designed* to use a high level of global NFB. I could lower the 'black box' distortion of KISASS by using a different 'open loop' topology with global NFB, but then it wouldn't meet the design principles. The JLH design doesn't even look "optimum" in the context of 1969. It does to me, but I'm not going to get into an argument regarding the definition of the state of the art in 1969. I would think a more nearly "optimum" design would be to graft the first two stages of the JLH design onto your output stage, eliminating the distortion produced by JLH's odd output stage. JLH didn't think so, and he is regarded by many as one of the finest audio designers who ever lived, indeed he's written a couple of excellent textbooks on the subject. But you are not regarded as one of the finest designers, and you have not written any books on the subject. There *is* a difference between you and JLH. You hate tubes, and won't build your own ideas. Patrick Turner. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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"Stewart Pinkerton" (John Byrns) wrote: The JLH design doesn't even look "optimum" in the context of 1969. It does to me, ** How completely asinine - even for a Posturing Pommy Turd. I would think a more nearly "optimum" design would be to graft the first two stages of the JLH design onto your output stage, eliminating the distortion produced by JLH's odd output stage. JLH didn't think so, ** Now the Posturing Pommy Turd presumes to know exactly what JLH was thinking back in 1969 !! He has the hide of 10 rhinos !!!!! From the June 2004 issue of EW we learn that JLH submitted his "10 watt class A" design in 1969 for their Circuit Ideas pages. Quote from p. 52: "John thought it a trifle ...... " . Staff at WW back then thought it interesting enough to turn into a feature article - mainly because it WAS a class A amp and therefore free from the bogey of crossover distortion. Paranoid, anti solid-state audiophools of that era were obsessed with the imagined evils of class AB - despite the Quad 303 having appeared a whole year earlier and demonstrated complete freedom from the effect and with a THD residual at 1 kHz of around 0.003%. " Stewart Pinkerton | Massive Fart - All else is Bull**** " .............. Phil |
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On Sun, 27 Mar 2005 21:31:20 +1000, Patrick Turner
wrote: Stewart Pinkerton wrote: On Sat, 26 Mar 2005 17:20:28 -0600, (John Byrns) wrote: I would think a more nearly "optimum" design would be to graft the first two stages of the JLH design onto your output stage, eliminating the distortion produced by JLH's odd output stage. JLH didn't think so, and he is regarded by many as one of the finest audio designers who ever lived, indeed he's written a couple of excellent textbooks on the subject. But you are not regarded as one of the finest designers, and you have not written any books on the subject. There *is* a difference between you and JLH. Indeed there is, which is why I will not argue against his designs. You hate tubes, and won't build your own ideas. Hatred implies a degree of emotional involvement. I regard tubes as an essential part of the *history* of electronics, and I have stated ad nauseam that KISASS is not something which I would care to build, as it is simply a BJT realisation of what I consider to be a fatally flawed design theory. I have of course built a couple of dozen of my other, more rational, audio ideas. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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On Sun, 27 Mar 2005 21:21:44 +1000, Patrick Turner
wrote: Stewart Pinkerton wrote: On Sat, 26 Mar 2005 23:17:58 +1100, Patrick Turner wrote: KISASS has quite different design constraints, and is intended to follow the unlikely phlosophy that loop NFB is evil, as is symmetrical push-pull operation, and that it's only linearity below 1 watt that matters for 'ultra fidelity'. Regarding push-pull operation, the output emitter followers are of course arranged in push-pull, but the distortion levels of output and input EFs are so tiny that the amplifier transfer curve is totally dominated by the central gain stage - which is the essence of the design. -- But you use an enormous amount of NFB in 3 loops in kissass. It upends the correctness of anything you say. Cut the crap Turner, no one but you believes that these are any kind of loops. And KISSASS isn't my design. I'll cut you a nice slice of crap, and serve it up to you when I see fit. I'm sure that you have an ample supply ready to hand. Bon apertite. That's 'bon appetit', you colonial ignoramus. So whose design was KISSASS? Santa Claws? John Byrns. And you don't wanna build or test anything. Not KISASS, as already stated. Your'e looking worse and worse and more irelevant day by day.... That's 'irrelevant', and how would you know? And certainly not KISS, should Jute ever get around to actually creating it as a finished design, rather than generating endless attack threads. But why should he hurry? Rome wasn't built in a day. And you attract such a lot of flack, so don't complain. Rome was not, but there's no such thing as a competent single-ended 300B design. It's often forgotten that, 70 years ago when the 300B was created, the classic movie theater amps for which the 300B was created were push-pull. In *those* days, tube amp designers were interested in *progressing* the art, not reverting to obsolete topologies because of loony-tunes theories.................. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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On Sun, 27 Mar 2005 21:45:55 +1000, "Phil Allison"
wrote: "Stewart Pinkerton" (John Byrns) wrote: The JLH design doesn't even look "optimum" in the context of 1969. It does to me, ** How completely asinine - even for a Posturing Pommy Turd. How would *you* have any clue? I would think a more nearly "optimum" design would be to graft the first two stages of the JLH design onto your output stage, eliminating the distortion produced by JLH's odd output stage. JLH didn't think so, ** Now the Posturing Pommy Turd presumes to know exactly what JLH was thinking back in 1969 !! He has the hide of 10 rhinos !!!!! Hardly a difficult deduction, since if he *had* thought so, he would have designed it that way. It would seem that you are not quite so sharp as a football.......................... From the June 2004 issue of EW we learn that JLH submitted his "10 watt class A" design in 1969 for their Circuit Ideas pages. Quote from p. 52: "John thought it a trifle ...... " . Indeed so, for him................ Staff at WW back then thought it interesting enough to turn into a feature article - mainly because it WAS a class A amp and therefore free from the bogey of crossover distortion. Indeed so, and it is. Paranoid, anti solid-state audiophools of that era were obsessed with the imagined evils of class AB - despite the Quad 303 having appeared a whole year earlier and demonstrated complete freedom from the effect and with a THD residual at 1 kHz of around 0.003%. But tubies in general also hate class AB, so where's the issue? Get back to us when you've grown a functioning brain. -- Stewart Pinkerton | Music is Art - Audio is Engineering |
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