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#81
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sat, 22 Jul 2006 19:56:18 GMT, Phat Bytestard
wrote: On Sat, 22 Jul 2006 11:48:12 +0100, Eeyore m Gave us: They fail to mention carbon film which is very widely used. The entire selling point of the sheet was that they are very low noise compared to other resistor manufacturing mediums. Noise in a resistor occurs because resistance mediums are actually heavily diluted semiconductors. The electrons bang around on their way through. It's a loose lattice. In a current flow in metals, electron-lattice interactions tend to space electrons evenly, so their exit from the resistor is more regular than a random (Poisson) distribution, so current-modulation noise is far below the shot noise level you'd get for uncorrelated conduction. The physically longer the resistor, the better the smoothing effect. This works less well in non-metal conductors, with a few exceptions. That doesn't affect Johnson noise of course; that only depends on the resistance and the temperature, as required by conservation of energy. John |
#82
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Phat Bytestard wrote: On Sat, 22 Jul 2006 11:48:12 +0100, Eeyore Gave us: They fail to mention carbon film which is very widely used. The entire selling point of the sheet was that they are very low noise compared to other resistor manufacturing mediums. Perfectly true but essentially irrelevant in most audio usage. In fact I can think of no problems with using metal film anywhere in audio and CF is fine for the most part too. Graham |
#83
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Phat Bytestard wrote: On Sat, 22 Jul 2006 20:28:55 +0100, Eeyore Gave us: Leaving out of the widest used ! In the audio industry? Unquestionably, at least before widespread use of SMT. Actually, that not a subject I've yet looked into in depth. Any ideas what commodity SMT resistors behave like ? I've got reason to suspect some may be inferior noise wise to leaded CF. Graham |
#84
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
In article ,
John Larkin wrote: [...] Of course, if you keep DC away from critical resistors, the shot noise becomes a tiny signal gain modulation that can hardly ever matter. It is not quite just a "gain modulation" there is also a phase modulation component to it. This phase modulation is less than what you would get from an equivelent amount of signal independant noise. -- -- forging knowledge |
#85
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Eeyore wrote
in : Phat Bytestard wrote: On Sat, 22 Jul 2006 20:28:55 +0100, Eeyore Gave us: Leaving out of the widest used ! In the audio industry? Unquestionably, at least before widespread use of SMT. Actually, that not a subject I've yet looked into in depth. Any ideas what commodity SMT resistors behave like ? I've got reason to suspect some may be inferior noise wise to leaded CF. Graham http://www.resistor.com/ -- Bob Quintal PA is y I've altered my email address. -- Posted via a free Usenet account from http://www.teranews.com |
#86
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Hi Mark,
Yes, the VH guy bought the equipment and makes the caps himself. The ones I recvd were labelled, by hand, with their actual value on one end. I installed the four smallest ones. Even if the $50. each is pure profit, he isn't going to be buying an NFL team this year. Of course, neither is anyone here on RAT I may only indulge in such sophistry because the house I bought as a struggling young software geek continued to appreciate and is now worth more than I ever imagined. Inflation keeps going, even if you get too sick to give a **** anymore for ten years. I dunno, the local deli is mediocre, at best, and I still can't see the waves of Malibu, but, something has these young Real Estate investors fired up ... I guess you get out of college and pick up the ball and run with it. Even if you are a thousand miles from anywhere or anything, except pretty rocks in huge piles ... My fantasies of magic capdom continue to intensify. Mr. VH is a genius, unlike my fellow posers on this disgusting NG OK, I am disabled and it is 118F outside. Why are you ******s wasting Saturday posting drivel? Happy Ears! Al Mark S wrote: Hi Al, Good to see you back. RAT is pretty much as you remember, with all the personalities in good working order (as you already see)! Boy, for your first thread in good long time, you really hit it out of the park! Lots of different opinions and rants but the cap price is probably indicative of the labor / set up time for a special low volume product, not necessarily ALL profit. Whether it is worthwhile is really up to the individual considering. Me, that's unexplored territory (expensive audio caps) but I hear better things with tubes which some say is nonsense too...so?? We'll see. MarkS |
#87
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sat, 22 Jul 2006 21:40:41 +0100, in sci.electronics.design Eeyore
wrote: Phat Bytestard wrote: On Sat, 22 Jul 2006 20:28:55 +0100, Eeyore Gave us: Leaving out of the widest used ! In the audio industry? Unquestionably, at least before widespread use of SMT. Actually, that not a subject I've yet looked into in depth. Any ideas what commodity SMT resistors behave like ? I've got reason to suspect some may be inferior noise wise to leaded CF. Graham http://www.prodigy-pro.com/forum/vie...972bc24e5d26ae martin |
#88
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
John Larkin wrote:
On Sat, 22 Jul 2006 19:56:18 GMT, Phat Bytestard wrote: On Sat, 22 Jul 2006 11:48:12 +0100, Eeyore om Gave us: They fail to mention carbon film which is very widely used. The entire selling point of the sheet was that they are very low noise compared to other resistor manufacturing mediums. Noise in a resistor occurs because resistance mediums are actually heavily diluted semiconductors. The electrons bang around on their way through. It's a loose lattice. In a current flow in metals, electron-lattice interactions tend to space electrons evenly, so their exit from the resistor is more regular than a random (Poisson) distribution, so current-modulation noise is far below the shot noise level you'd get for uncorrelated conduction. The physically longer the resistor, the better the smoothing effect. This works less well in non-metal conductors, with a few exceptions. That doesn't affect Johnson noise of course; that only depends on the resistance and the temperature, as required by conservation of energy. John Oh, man, this old chestnut again. Of course you're perfectly right, John, but the effort is doomed because half your audience appears to think that classical thermodynamics is a matter of opinion. Why don't we all vote on it and find out how resistors *really* behave? Cheers, Phil Hobbs |
#89
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
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#90
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sat, 22 Jul 2006 17:52:39 -0400, Phil Hobbs
wrote: John Larkin wrote: On Sat, 22 Jul 2006 19:56:18 GMT, Phat Bytestard wrote: On Sat, 22 Jul 2006 11:48:12 +0100, Eeyore . com Gave us: They fail to mention carbon film which is very widely used. The entire selling point of the sheet was that they are very low noise compared to other resistor manufacturing mediums. Noise in a resistor occurs because resistance mediums are actually heavily diluted semiconductors. The electrons bang around on their way through. It's a loose lattice. In a current flow in metals, electron-lattice interactions tend to space electrons evenly, so their exit from the resistor is more regular than a random (Poisson) distribution, so current-modulation noise is far below the shot noise level you'd get for uncorrelated conduction. The physically longer the resistor, the better the smoothing effect. This works less well in non-metal conductors, with a few exceptions. That doesn't affect Johnson noise of course; that only depends on the resistance and the temperature, as required by conservation of energy. John Oh, man, this old chestnut again. Of course you're perfectly right, John, but the effort is doomed because half your audience appears to think that classical thermodynamics is a matter of opinion. Why don't we all vote on it and find out how resistors *really* behave? Cheers, Phil Hobbs Phil, Do metal-oxide thickfilm resistors have shot noise? Any idea how much, as, say, % of full shot? John |
#91
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
John Larkin wrote:
On Sat, 22 Jul 2006 17:52:39 -0400, Phil Hobbs wrote: John Larkin wrote: On Sat, 22 Jul 2006 19:56:18 GMT, Phat Bytestard wrote: On Sat, 22 Jul 2006 11:48:12 +0100, Eeyore .com Gave us: They fail to mention carbon film which is very widely used. The entire selling point of the sheet was that they are very low noise compared to other resistor manufacturing mediums. Noise in a resistor occurs because resistance mediums are actually heavily diluted semiconductors. The electrons bang around on their way through. It's a loose lattice. In a current flow in metals, electron-lattice interactions tend to space electrons evenly, so their exit from the resistor is more regular than a random (Poisson) distribution, so current-modulation noise is far below the shot noise level you'd get for uncorrelated conduction. The physically longer the resistor, the better the smoothing effect. This works less well in non-metal conductors, with a few exceptions. That doesn't affect Johnson noise of course; that only depends on the resistance and the temperature, as required by conservation of energy. John Oh, man, this old chestnut again. Of course you're perfectly right, John, but the effort is doomed because half your audience appears to think that classical thermodynamics is a matter of opinion. Why don't we all vote on it and find out how resistors *really* behave? Cheers, Phil Hobbs Phil, Do metal-oxide thickfilm resistors have shot noise? Any idea how much, as, say, % of full shot? John I don't know. The physics is quite a bit more complicated than in metal, so I can't say from first principles, and I haven't measured it. Most of my circuits are built from a huge supply of 1% metal film resistors I bought in about 1989! It might be quite interesting to measure. Cheers, Phil Hobbs |
#92
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
John Larkin wrote: Do metal-oxide thickfilm resistors have shot noise? Any idea how much, as, say, % of full shot? I'm curious myself. My early low noise designs used metal oxide since that was then the readily available low-noise type. I can't quote any data as such but ISTR that metal film when it took over that market was understod to be fractionally noisier. Graham |
#93
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
John Larkin wrote: On 22 Jul 2006 11:40:10 -0700, wrote: Bob Quintal wrote: John Larkin wrote in : On Sat, 22 Jul 2006 11:48:12 +0100, Eeyore wrote: Definitely written by the marketing dept and a poor show on Vishay's part. Graham It is true that metallic resistors have much less shot noise (which they strangely call "current noise") than carbon or oxide resistors, which might matter in audio applications but seldom does. In something without DC bias, like an attenuator, it simply won't matter. Maybe Vishay hired that id10t Kevin Aylward, who called me all sorts of terrible things when I told him that resistors have shot noise... and said a lot of other remarkably stupid things as well. Good resistors don't have shot noise - which is what you see when your current is flowing as single non-interacting electrons or holes, so that the currnt is genuinely quantised. Good resistors do have Johnson noise, which simply reflects the electron cloud carrying the current is a room temperature so that the individual electroncs are doing a bit of Brownian motion on top of the drift due to the elecric field. Crap resistors have "excess noise" which is to say, more than Johnson noise. Kevin Alyward understands this sort of stuff, and you clearly don't. http://www.lorentz.leidenuniv.nl/bee...ise/noise.html http://www.eng.yale.edu/qlab/papers/..._shotnoise.pdf http://www.journals.uchicago.edu/AJ/...667932863Guest I think that carbon and thickfilm (metal oxide) resistors have serious shot noise, and metallic resistors have very little, at least until they get very small. I don't know if thickfilms approach or exceed Poisson-level noise, or exactly what "very small" is; clarifications would be appreciated. Of course, if you keep DC away from critical resistors, the shot noise becomes a tiny signal gain modulation that can hardly ever matter. I'd be very surprised if the excess noise in carbon film and carbon composition resistors had much to do with shot noise - carbon has a positive temperature coefficient of resistance, and any path that starts off carrying more current than its neighbours is going to carry more current still - you don't get active channelling at normal current and voltage levels, but the current distribution across the restive paths is going to change with changing current level. Thick film resitors, built up from a mixture of glass and metal oxide, can do practically anything, so I suppose shot-noise has to be one of the possibilities. "Excess noise" is probably a better phrase to use, since it doesn't delude the user into thinking that "shot noise"is the only source of excess noie in these devices. -- Bill Sloman, Nijmegen |
#94
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
In article ,
John Larkin wrote: [.. Shot noise as phase noise ..] That surely can't matter until microwave frequencies, and who needs a ppm-accurate resistance at microwave? Don't call me Shirly! : I think it is an extra noise source for high frequency PLLs and atomic clocks and the like. If it was only a variation in amplitude, it would not add any noise. -- -- forging knowledge |
#95
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
That was a joke, of course. However, for Wikipedia indeed I have great
distrust, since with a little research some very serious issues about the editorial wars and various unscrupulous practices of Wikipedia's overseers come up. The truth is that in a democracy one gets the rule of the lowest common denominator -- and that's a bad thing. Eeyore wrote in : Prune wrote: Eeyore wrote in : Your argument incidentally could also be levelled at idiots with their own websites. As in any ****tard can put their own website online. There is *no* safeguard about these whatever and indeed they pose a greater risk. Indeed, that's why I only trust corporate and government websites. Including Vishay's ? ;~) Graham |
#96
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
John Larkin wrote in
: http://www.eng.yale.edu/qlab/papers/..._shotnoise.pdf They call it "current noise" right in the abstract, as the Vishay people do. |
#97
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Prune wrote: Patrick Turner wrote in : teflon, then they move to oilers I don't get the oil thing at all, seems inconsistent to me -- oil has a high dielectric constant, just the opposite of what the reasoning for using Teflon seems to be (and of course the dielectric constant of polypropylene is even lower than Teflon). The only thing that makes sense is that foil would be better than film, for the same reason Vishay makes metal foil resistors along their metal film line (they have a white paper explaining why it matters, to what extent it's just marketing I can't judge). The dielectric constant is an issue with caps. But not in coupling caps in tube amps where the charge across a cap remains virtually unchanged while the amp is running. A 0.47uF feeding a 220k grid bias R forms an impedance divider network with the cap having maximum Z at LF. At 100Hz the ZC = 3.4k. So where you have 100Vrms across the 220k the current = 0.45mA, and so there is 1.5Vrms across the cap at 100Hz. If the distortion in the cap is 0.01% which is all you'd ever expect to measure, it could be 10 times less, then the distortion voltage = 1.5 x 0.0001 = 0.00015vrms, and this is a tiny fraction of the 100Vrms across the 220k, and the cap caused distortion would be 1.5uV, about - 116bD, well below the noise floor of the amp. The worst case scenario for distortion numbers does indicate that any old cap will do for coupling. Perhaps there is something I have missed here about what makes caps have a different sound. But all the guys who say caps make a difference will not subject themselves to AB tests where they are required to identify which amp has what caps. They just like to believe pretty and expensive caps make a difference. Its a bit neurotic. Christmas is a time for celebration of Christ's birth. Having the best Christmas lights on a christmas tree does not celebrate Christmas any better; the lights merely celebrate idiotic shopping habits. Some people like to celebrate Christmas in July in a day or two and some like to replace caps more often than underpants. I leave them to happily enjoy their truths as they believe in. My best wishes. Patrick Turner. |
#98
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Audio Note still makes tantalum oxide resistors.
Eeyore wrote in : John Larkin wrote: Do metal-oxide thickfilm resistors have shot noise? Any idea how much, as, say, % of full shot? I'm curious myself. My early low noise designs used metal oxide since that was then the readily available low-noise type. I can't quote any data as such but ISTR that metal film when it took over that market was understod to be fractionally noisier. Graham |
#99
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Double blind ABC/hidden reference is the established standard for
perceptual comparisons. It's often used for example by audio and video codec developers, and there is various software available to automate it. Patrick Turner wrote in : Prune wrote: Patrick Turner wrote in : teflon, then they move to oilers I don't get the oil thing at all, seems inconsistent to me -- oil has a high dielectric constant, just the opposite of what the reasoning for using Teflon seems to be (and of course the dielectric constant of polypropylene is even lower than Teflon). The only thing that makes sense is that foil would be better than film, for the same reason Vishay makes metal foil resistors along their metal film line (they have a white paper explaining why it matters, to what extent it's just marketing I can't judge). The dielectric constant is an issue with caps. But not in coupling caps in tube amps where the charge across a cap remains virtually unchanged while the amp is running. A 0.47uF feeding a 220k grid bias R forms an impedance divider network with the cap having maximum Z at LF. At 100Hz the ZC = 3.4k. So where you have 100Vrms across the 220k the current = 0.45mA, and so there is 1.5Vrms across the cap at 100Hz. If the distortion in the cap is 0.01% which is all you'd ever expect to measure, it could be 10 times less, then the distortion voltage = 1.5 x 0.0001 = 0.00015vrms, and this is a tiny fraction of the 100Vrms across the 220k, and the cap caused distortion would be 1.5uV, about - 116bD, well below the noise floor of the amp. The worst case scenario for distortion numbers does indicate that any old cap will do for coupling. Perhaps there is something I have missed here about what makes caps have a different sound. But all the guys who say caps make a difference will not subject themselves to AB tests where they are required to identify which amp has what caps. They just like to believe pretty and expensive caps make a difference. Its a bit neurotic. Christmas is a time for celebration of Christ's birth. Having the best Christmas lights on a christmas tree does not celebrate Christmas any better; the lights merely celebrate idiotic shopping habits. Some people like to celebrate Christmas in July in a day or two and some like to replace caps more often than underpants. I leave them to happily enjoy their truths as they believe in. My best wishes. Patrick Turner. |
#100
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sun, 23 Jul 2006 03:47:58 GMT, Prune
wrote: John, can you recommend resistors then? I'm not even sure what properties to look at. Some posters say TCR, some VCR (and for the latter I find it near impossible to find numbers from the manufacturer). For audio, any resistor, the cheapest thing in the Mouser catalog. In the unlikely case that there's a lot of DC across it, and the signal level is very low, one might argue against carbon comps, but that's about it. And oh, in s.e.d. at least, we consider bottom-posting to be polite. John |
#101
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Well, I'm a pianist as well, and a bit of an organist, but I think I may
still need some translation of that post... " wrote in oups.com: Hi RATs! Objectivists are nice people who make all the correct technical choices for all the wrong reasons. Of course it doesn't make sense. Recreating portions of an empathic artistic experience requires a bit more than a high rez copier Nice write ups on: http://www.clarisonus.com/blog/ Well, except for my brain dead trailer trash gurglings ... Happy Ears! Al PS I once (ca. 1967) worked as a guard at the Walker Art Center in Minneapolis. When patrons asked if these were real paintings and sculptures, I reassured them (I lied, OK?) they were just copies (people were fearful the originals might get damaged, no one would bother defacing a mere copy, back in them good old days). Minneapolis was once a great distance from Athens, Rome, London and Paris. No longer far enough, sigh. Nepal is just a train ride away, these days. PPS I am married to a pianist. I love her and her friends much more than any of the dip**** engineers I ever worked with. Sorry, technical descriptions are never literature, even, or perhaps especially, when marketing tries to pretty them up with fancy lies Prune wrote: Well, it's certainly a creative comeback, if one that doesn't quite make sense... " wrote Hi RATs! The Object of your affection has given you an infection. Nothing to be done but cut off your head Happy Ears! Al |
#102
Posted to rec.audio.tubes
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Sorry about this, I didn't realize I was crossposting; my stupid client
only seems to alert if there are four or more groups in the list. John Larkin wrote in : On Sun, 23 Jul 2006 03:47:58 GMT, Prune wrote: John, can you recommend resistors then? I'm not even sure what properties to look at. Some posters say TCR, some VCR (and for the latter I find it near impossible to find numbers from the manufacturer). For audio, any resistor, the cheapest thing in the Mouser catalog. In the unlikely case that there's a lot of DC across it, and the signal level is very low, one might argue against carbon comps, but that's about it. And oh, in s.e.d. at least, we consider bottom-posting to be polite. John |
#103
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sat, 22 Jul 2006 18:29:44 -0400, Phil Hobbs
wrote: John Larkin wrote: On Sat, 22 Jul 2006 17:52:39 -0400, Phil Hobbs wrote: John Larkin wrote: On Sat, 22 Jul 2006 19:56:18 GMT, Phat Bytestard wrote: On Sat, 22 Jul 2006 11:48:12 +0100, Eeyore l.com Gave us: They fail to mention carbon film which is very widely used. The entire selling point of the sheet was that they are very low noise compared to other resistor manufacturing mediums. Noise in a resistor occurs because resistance mediums are actually heavily diluted semiconductors. The electrons bang around on their way through. It's a loose lattice. In a current flow in metals, electron-lattice interactions tend to space electrons evenly, so their exit from the resistor is more regular than a random (Poisson) distribution, so current-modulation noise is far below the shot noise level you'd get for uncorrelated conduction. The physically longer the resistor, the better the smoothing effect. This works less well in non-metal conductors, with a few exceptions. That doesn't affect Johnson noise of course; that only depends on the resistance and the temperature, as required by conservation of energy. John Oh, man, this old chestnut again. Of course you're perfectly right, John, but the effort is doomed because half your audience appears to think that classical thermodynamics is a matter of opinion. Why don't we all vote on it and find out how resistors *really* behave? Cheers, Phil Hobbs Phil, Do metal-oxide thickfilm resistors have shot noise? Any idea how much, as, say, % of full shot? John I don't know. The physics is quite a bit more complicated than in metal, so I can't say from first principles, and I haven't measured it. Most of my circuits are built from a huge supply of 1% metal film resistors I bought in about 1989! It might be quite interesting to measure. Cheers, Phil Hobbs It is interesting; I'll try it soon. I have a nice selection of most everything - carbon film, metal films, cermets - but not much in the way of carbon comps. I'm thinking 9 volt battery, small resistor and BFC filter cap, two identical 100K resistors as a voltage divider, Tek AM502 amp, rms DVM. That shouldn't be hard. What's the math of the voltage divider as, say, my measured noise relative to the noise one resistor would show at that same (constant) current? I guess it's two noise sources connected in parallel, so 0.707? John |
#104
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
I've tried cermet potentiometers for volume control, and in a blind test
(non-double, used dual switch with my friend) I can't tell the difference between it and a stepped attenuator; however, in 7/10 trials me and 8/10 trials him heard difference between plastic pot and the cermet, both preferring the cermet. John Larkin wrote in : It is interesting; I'll try it soon. I have a nice selection of most everything - carbon film, metal films, cermets - but not much in the way of carbon comps. |
#105
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Er, by plastic pot I meant the conductive plastic ones such as Alps.
Prune wrote in 4.76: I've tried cermet potentiometers for volume control, and in a blind test (non-double, used dual switch with my friend) I can't tell the difference between it and a stepped attenuator; however, in 7/10 trials me and 8/10 trials him heard difference between plastic pot and the cermet, both preferring the cermet. John Larkin wrote in : It is interesting; I'll try it soon. I have a nice selection of most everything - carbon film, metal films, cermets - but not much in the way of carbon comps. |
#106
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Hi RATs!
OK. I like to swap parts in my system and listen. I am a hobbyist, not an electronic design engineer. My wives, yes, I have had two, are both musicians. They live to make music. OK, current Mrs. is sicker than me, but, she made Music her life, when she could. The former Mrs. teaches Music and performs. Well, she did, we are a bit out of touch ... I played guitar, a lot, but, I was never a musician. I know this. My musician friends know this. It is not a crime, it is just life. I had a few good moments. I am able to hear people who have had many great decades, it is all quantifiable, sort of Objective analysis of a signal in the current space compared to that signal in the recording is all a meer mortal has to judge his efforts. That does not mean everything we hear when we listen is fully and completely captured in the recording. Even though the recording itself may well capture much more than any listener at the original performance. Music only happens in our mind after all the dire transmission business is long completed. What Music gets through from the performers to the listeners has some components which are simply not physically in the sounds. They are imagined or inferred from the sounds. It is not possible to test for those inferrences from comparing the recording to the reproduced sound. Only people can hear what is not physically there. We are crazy, in that sense. Trying to make Music fit into the parts we can control is a waste of time. Let us enjoy the Music without demanding that we swear never to hear what is not on the recording itself. We can't. Even live performance listeners sometimes hear things which only they heard. Nobody checks our aural memories looking for misinterpretations. I don't mind tuning my system to provide me with something which makes me feel the Music is getting through ... that is what being alive is for, for me. Making the system simply reproduce the recording is simpler and more easily verified. It is not the same. Trust me Or not, your choice .... Happy Ears! Al Prune wrote: Well, I'm a pianist as well, and a bit of an organist, but I think I may still need some translation of that post... |
#107
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Prune wrote: Prune wrote in 4.76: I've tried cermet potentiometers for volume control, and in a blind test (non-double, used dual switch with my friend) I can't tell the difference between it and a stepped attenuator; however, in 7/10 trials me and 8/10 trials him heard difference between plastic pot and the cermet, both preferring the cermet. John Larkin wrote in : It is interesting; I'll try it soon. I have a nice selection of most everything - carbon film, metal films, cermets - but not much in the way of carbon comps. Er, by plastic pot I meant the conductive plastic ones such as Alps. I can't say I was aware that Alps made any conductive plastic types. A better test would be Vishay-Sfernice's P11(cermet) vs PA11( conductive plastic) http://www.vishay.com/doc?51031 Note that the conductive plastic part is recommended for audio. Graham |
#108
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Prune wrote: I've tried cermet potentiometers for volume control, and in a blind test (non-double, used dual switch with my friend) I can't tell the difference between it and a stepped attenuator; however, in 7/10 trials me and 8/10 trials him heard difference between plastic pot and the cermet, both preferring the cermet. The question is what was it you were hearing or thinking you were hearing ? Graham |
#109
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Patrick Turner wrote: The dielectric constant is an issue with caps. With film caps ? Any plastic film cap ? But not in coupling caps in tube amps where the charge across a cap remains virtually unchanged while the amp is running. If the distortion in the cap is 0.01% which is all you'd ever expect to measure In a *film cap*. You have to be barking mad ! I've only ever measured that kind of distortion with zero bias electrolytics under worst case conditions ! Film caps have distortion that is umeasurably small. Certainly less than an AP test set can measure and that means 0.0007% Indeed measure an AP back to back and you get ~ 0.0006-0.0007% and there's several film caps in the circuit already. If you're going to make comments of that nature you'll need to be able to back them up. Graham |
#111
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
I don't have a Stereophile reviewer's vocabulary of terms to easily explain
it. Suffice it to say it was a very small difference (I failed in 3 of the 10 trials). Subjectively, I'm limited to saying I liked the cermet a bit better, but it's hard to be more specific. If you're interested, you may wish to try a similar test yourself. I've been planning for a while to interface motorized switchboxes to the abchr computer program so this can be automated and one can do blind testing without a helper, but it's hard to find time among the various projects... Eeyore wrote in : Prune wrote: I've tried cermet potentiometers for volume control, and in a blind test (non-double, used dual switch with my friend) I can't tell the difference between it and a stepped attenuator; however, in 7/10 trials me and 8/10 trials him heard difference between plastic pot and the cermet, both preferring the cermet. The question is what was it you were hearing or thinking you were hearing ? Graham |
#112
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
The specific distortion profile matters. Summary measures are meaningless,
and at least one study shows _no_ correlation between something like THD and human perception of distortion (see http://www.gedlee.com/distortion_perception.htm for their AES paper and study results). Eeyore wrote in : Patrick Turner wrote: The dielectric constant is an issue with caps. With film caps ? Any plastic film cap ? But not in coupling caps in tube amps where the charge across a cap remains virtually unchanged while the amp is running. If the distortion in the cap is 0.01% which is all you'd ever expect to measure In a *film cap*. You have to be barking mad ! I've only ever measured that kind of distortion with zero bias electrolytics under worst case conditions ! Film caps have distortion that is umeasurably small. Certainly less than an AP test set can measure and that means 0.0007% Indeed measure an AP back to back and you get ~ 0.0006-0.0007% and there's several film caps in the circuit already. If you're going to make comments of that nature you'll need to be able to back them up. Graham |
#113
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Prune wrote: Eeyore wrote in : Prune wrote: I've tried cermet potentiometers for volume control, and in a blind test (non-double, used dual switch with my friend) I can't tell the difference between it and a stepped attenuator; however, in 7/10 trials me and 8/10 trials him heard difference between plastic pot and the cermet, both preferring the cermet. The question is what was it you were hearing or thinking you were hearing ? Graham I don't have a Stereophile reviewer's vocabulary of terms to easily explain it. Your description would do actually, I'm not impressed by those f***wit reviews that talk about improving pace and speed one bit. Suffice it to say it was a very small difference (I failed in 3 of the 10 trials). Subjectively, I'm limited to saying I liked the cermet But how so ? a bit better, but it's hard to be more specific. If you're interested, you may wish to try a similar test yourself. I wouldn't personally waste my time on something with no scientific basis i.e. cermet vs CP. I do however have an interest in whether low-level vibration ( from the audio ) can cause issues in circuitry. I've been planning for a while to interface motorized switchboxes to the abchr computer program so this can be automated and one can do blind testing without a helper, but it's hard to find time among the various projects... Graham |
#114
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Prune wrote: Eeyore wrote in : Patrick Turner wrote: The dielectric constant is an issue with caps. With film caps ? Any plastic film cap ? But not in coupling caps in tube amps where the charge across a cap remains virtually unchanged while the amp is running. If the distortion in the cap is 0.01% which is all you'd ever expect to measure In a *film cap*. You have to be barking mad ! I've only ever measured that kind of distortion with zero bias electrolytics under worst case conditions ! Film caps have distortion that is umeasurably small. Certainly less than an AP test set can measure and that means 0.0007% Indeed measure an AP back to back and you get ~ 0.0006-0.0007% and there's several film caps in the circuit already. If you're going to make comments of that nature you'll need to be able to back them up. Graham The specific distortion profile matters. Profile ? You mean harmonic distribution ? There's some evidence that's so when it's audible but seriously 0.0007% = -103dB and by inference ( understanding of the underlying science - and in this case the circuitry too ) actually no distortion at all ? Show me some results that provide evidence for film caps distorting and I'll listen. Bear in mind that I have run my own tests which show even electrolytics to be blameless when used intelligently ( but many designs don't - hence the bad rep they've got ). Summary measures are meaningless, and at least one study shows _no_ correlation between something like THD and human perception of distortion (see http://www.gedlee.com/distortion_perception.htm for their AES paper and study results). Not quite *no correlation* actually but simple percentages aren't all that matters for sure. Graham |
#115
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
Eeyore wrote in
: I wouldn't personally waste my time on something with no scientific basis i.e. cermet vs CP. Parasitic capacitance of the conductive plastic is high. If the following stage has a high input impedance, it could make a frequency response difference. Cermets have a problem that they wear down I guess. In any case, I always err on the safe side in that who knows whether a difference is too small by itself but may add up above a threshold when combined with other changes, so I ended up making a motorized step attenuator. I do however have an interest in whether low-level vibration ( from the audio ) can cause issues in circuitry. You mean by vibrating the wiper contact? I think the spring pressure is too high for that. I've only noticed vibration issues with tubes. |
#116
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Eeyore wrote in
: Profile ? You mean harmonic distribution ? I mean examples such as the nonlinear distortion discussed in the reference I cited. Hakwsford also has some AES papers on the subject. that's so when it's audible but seriously 0.0007% = -103dB and by inference ( understanding of the underlying science - and in this case the circuitry too ) actually no distortion at all ? Probably. But that's the thing, I can't be sure that as multiple sub- threshold changes are made, they may not add up to make a perceptible difference. Of course, other things I do purely for the 'coolness' factor, such as silver/teflon cables. I've no doubt that silver and copper cannot be aurally distinguished, yet I thought it would be cool to use silver. As for cable geometry, on the other hand, I can believe that in really long interconnects parastic reactances could matter. In my case I used the double-helix wound on a hollow tube, and on an LCR meter it measured much lower capacitance than other cables I tried. But again, I doubt I can hear a difference on short interconnects like that and with my current equipment. If I was using a passive preamp, though, maybe the high output impedance could cause some HF roloff combined with the cable capacitance. |
#117
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sat, 22 Jul 2006 13:28:45 -0700, John Larkin
Gave us: That doesn't affect Johnson noise of course; that only depends on the resistance and the temperature, as required by conservation of energy. Anything above absolute zero not only emits IR energy, but electrical noise as well. (speaking of electrical mediums, of course) Why do IR camera CCDs need LN baths? Noise floor. |
#118
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sat, 22 Jul 2006 23:28:18 +0200, martin griffith
Gave us: Snip Interesting discussion. |
#119
Posted to rec.audio.tubes
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Teflon Film Tin Foil capacitors
Eeyore tiresomly proclaimed:
AIUI your mod increases distortion which some ppl find audibly pleasing. This may indeed 'enrich' listening for you but it has absolutely nothing to do with hi-fi... Says who? Why not? Someone said Al is a fashion victim, but looking at his list of equipment I can't see quite what fashion he might be a victim of. In your case it's obvious. What's happened to Stewart Pinkerton? His presentation of reproductionist dogma was rather more entertaining than yours. cheers, Ian |
#120
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
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Vishay talk ******** - was Teflon Film Tin Foil capacitors
On Sun, 23 Jul 2006 04:59:19 GMT, Prune
Gave us: I've tried Have you tried to STOP TOP POSTING? |
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