Reply
 
Thread Tools Display Modes
  #81   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
John Larkin John  Larkin is offline
external usenet poster
 
Posts: 51
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Ken Smith Ken Smith is offline
external usenet poster
 
Posts: 8
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Bob Quintal Bob Quintal is offline
external usenet poster
 
Posts: 107
Default 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   Report Post  
Posted to rec.audio.tubes
[email protected] tubegarden@aol.com is offline
external usenet poster
 
Posts: 142
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
martin griffith martin griffith is offline
external usenet poster
 
Posts: 22
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Phil Hobbs Phil Hobbs is offline
external usenet poster
 
Posts: 12
Default 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
  #90   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
John Larkin John  Larkin is offline
external usenet poster
 
Posts: 51
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Phil Hobbs Phil Hobbs is offline
external usenet poster
 
Posts: 12
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
[email protected] bill.sloman@ieee.org is offline
external usenet poster
 
Posts: 15
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Ken Smith Ken Smith is offline
external usenet poster
 
Posts: 8
Default 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   Report Post  
Posted to rec.audio.tubes
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes
Patrick Turner Patrick Turner is offline
external usenet poster
 
Posts: 3,964
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
John Larkin John  Larkin is offline
external usenet poster
 
Posts: 51
Default 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   Report Post  
Posted to rec.audio.tubes
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
John Larkin John  Larkin is offline
external usenet poster
 
Posts: 51
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes
[email protected] tubegarden@aol.com is offline
external usenet poster
 
Posts: 142
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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   Report Post  
Posted to rec.audio.tubes
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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

  #110   Report Post  
Posted to rec.audio.tubes
Bob H. Bob H. is offline
external usenet poster
 
Posts: 118
Default Teflon Film Tin Foil capacitors

I've got a ****load of "old ancient" 2 and 1 watt carbon comps, and
they sound sharp, clear, and marvelous wherever I put them in a
circuit. I guess I'm not an "audiopile", or whatever....


Bob H.


wrote:
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...




  #111   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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   Report Post  
Posted to rec.audio.tubes
Eeyore Eeyore is offline
external usenet poster
 
Posts: 1,297
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes
Prune Prune is offline
external usenet poster
 
Posts: 219
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Phat Bytestard Phat Bytestard is offline
external usenet poster
 
Posts: 42
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Phat Bytestard Phat Bytestard is offline
external usenet poster
 
Posts: 42
Default 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   Report Post  
Posted to rec.audio.tubes
Ian Iveson Ian Iveson is offline
external usenet poster
 
Posts: 960
Default 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   Report Post  
Posted to rec.audio.tubes,rec.audio.pro,sci.electronics.design
Phat Bytestard Phat Bytestard is offline
external usenet poster
 
Posts: 42
Default 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?
Reply
Thread Tools
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Comparing quality on vinyl with Digital thomh High End Audio 51 August 5th 04 12:56 AM
MKT foil capacitors Sean High End Audio 0 June 17th 04 11:36 PM
FS- AXIAL POLYPROPYLENE CAPACITORS [email protected] Marketplace 0 March 11th 04 05:47 PM
FS- RADIAL POLYPROPYLENE CAPACITORS [email protected] Marketplace 0 February 17th 04 08:24 AM
Why DBTs in audio do not deliver (was: Finally ... The Furutech CD-do-something) Bob Marcus High End Audio 313 September 9th 03 01:17 AM


All times are GMT +1. The time now is 04:54 PM.

Powered by: vBulletin
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 AudioBanter.com.
The comments are property of their posters.
 

About Us

"It's about Audio and hi-fi"