DESPERATE II
Hi Christer,
Let's just single out one factor here: DA.
Do you think it was called dielectrical absorbtion for any other reason then that the material used as a dielectricum had properties that more or less absorbed according to what chemical material was used for that?
Is it a good idea to use a dielectricum in a coupling cap that absorbs highly?
Now,what exactly will this dielectricum absorb you think?
Cheers,
Hi Christer,
Let's just single out one factor here: DA.
Do you think it was called dielectrical absorbtion for any other reason then that the material used as a dielectricum had properties that more or less absorbed according to what chemical material was used for that?
Is it a good idea to use a dielectricum in a coupling cap that absorbs highly?
Now,what exactly will this dielectricum absorb you think?
Cheers,
DA may or may not be a problem depending on the usage. Certainly, I wouldn't want a cap with high DA in a timer or sample/hold. But as a coupling cap that just handles AC, it may be no problem at all.
Jim Bongiorno (who designed some pretty highly regarded amps) once argued forcefully that an electrolytic carries no sonic penalty as an input cap. His reasoning was that any errors in the capacitive reactance are swamped by the large circuit impedances. He may be right, I don't know. I still haven't seen any proper listening tests by those who claim that an e'lytic in the circuit path will irredeemably foul the sound- though my little box project for Dorkus may bear fruit.
Jim Bongiorno (who designed some pretty highly regarded amps) once argued forcefully that an electrolytic carries no sonic penalty as an input cap. His reasoning was that any errors in the capacitive reactance are swamped by the large circuit impedances. He may be right, I don't know. I still haven't seen any proper listening tests by those who claim that an e'lytic in the circuit path will irredeemably foul the sound- though my little box project for Dorkus may bear fruit.
Re: DESPERATE II
You are not getting the point Frank. It is not about what you
or me think, it is not about what you or me (think we) hear.
If you are convinced and don't think it is necessary to investigate
further why, or even if, capacitors sound different, then fine, but
you must accept than some people desire facts and knowledge.
Yes, I am a scientist, so I may be harder to convince than most
people, but that is just because I know all too well how easily
false claims and conclusions can manifest themselves and
hamper progress until someone get the idea to question
something that has been taken for granted for a long time.
There are far too many such examples of "false truths" in
many sciences. Sometimes these beliefs are just plain wrong,
in other cases they are models which work fine in some cases
but will later be refined or replaced with better models. For
instance, many many lives have been lost due to such beliefs
in medicine, where something has manifested itself as a truth
although it has never really been investigated until someone
gets the idea to question it.
Further note, I am not suggesting that we here at DIY Audio
should do this research, but just that such research is needed
before we really know. Until then, we are left to our personal
beliefs in the matter.
fdegrove said:Hi Christer,
Let's just single out one factor here: DA.
Do you think it was called dielectrical absorbtion for any other reason then that the material used as a dielectricum had properties that more or less absorbed according to what chemical material was used for that?
Is it a good idea to use a dielectricum in a coupling cap that absorbs highly?
Now,what exactly will this dielectricum absorb you think?
Cheers,
You are not getting the point Frank. It is not about what you
or me think, it is not about what you or me (think we) hear.
If you are convinced and don't think it is necessary to investigate
further why, or even if, capacitors sound different, then fine, but
you must accept than some people desire facts and knowledge.
Yes, I am a scientist, so I may be harder to convince than most
people, but that is just because I know all too well how easily
false claims and conclusions can manifest themselves and
hamper progress until someone get the idea to question
something that has been taken for granted for a long time.
There are far too many such examples of "false truths" in
many sciences. Sometimes these beliefs are just plain wrong,
in other cases they are models which work fine in some cases
but will later be refined or replaced with better models. For
instance, many many lives have been lost due to such beliefs
in medicine, where something has manifested itself as a truth
although it has never really been investigated until someone
gets the idea to question it.
Further note, I am not suggesting that we here at DIY Audio
should do this research, but just that such research is needed
before we really know. Until then, we are left to our personal
beliefs in the matter.
ZOOMING IN.
Hi,
Christer,
Let's state for the record here that I've not even been talking about audible differences.
Also,let's stick to film caps and DA.
All else being kept constant a cap with a superior dielectric will remain a better cap all else being kept constant.Period.
If any of you would care to dig into a datasheet or read some manufacturers datasheets you would see it for yourself.
I see your point in wanting to correlate the audibility of that simple fact but isn't a fact a fact?
When you see a plot of a tube or semiconductor and it shows nonlinearities in its' frequency response does that then get questioned?
So,I ask,why should it be any different for capacitors?
One could really push this topic to the limit but it's been done before and I hate to oversample.
After all I may have missed the point entirely,
Hi,
Christer,
Let's state for the record here that I've not even been talking about audible differences.
Also,let's stick to film caps and DA.
All else being kept constant a cap with a superior dielectric will remain a better cap all else being kept constant.Period.
If any of you would care to dig into a datasheet or read some manufacturers datasheets you would see it for yourself.
I see your point in wanting to correlate the audibility of that simple fact but isn't a fact a fact?
When you see a plot of a tube or semiconductor and it shows nonlinearities in its' frequency response does that then get questioned?
So,I ask,why should it be any different for capacitors?
One could really push this topic to the limit but it's been done before and I hate to oversample.
After all I may have missed the point entirely,
I have to take some mild issue with what you say, Frank. What makes a dielectric "superior" for one thing will not necessarily make it "superior" for another. A teflon cap may be terrific for coupling the driver to the output stage in my power amp (because of the low dissipation factor), but its size (because of the low dielectric constant) makes it pretty lousy to use to couple the RF amp to the mixer in my tuner. A nice polystyrene cap is great for the sample and hold in my A/D converter (because of the low DA), but it would be a disaster as a compensation cap in my tube amp (because of the temperature sensitivity).
Your qualifying words "all else being kept constant," if interpreted literally, reduce what you say to a tautology.
Your qualifying words "all else being kept constant," if interpreted literally, reduce what you say to a tautology.
ASSUMPTIONS
Hi,
Right.
It is a tautology.
I feel at this point though that it was better suited to narrow the field of discussion for clarity's sake.
Hence,I also should add I'm talking about the capacitors for coupling purposes at audio frequencies.
Any other applications are indeed as you say.
D'haen and myself have hinted at that in this and probably other threads already.
In other words you subscribe to the same opinion.
"Malheureusement il faut casse des oeufs pour faire une ommelette,n'est-ce pas?"
Cheers,
Hi,
Right.
It is a tautology.
I feel at this point though that it was better suited to narrow the field of discussion for clarity's sake.
Hence,I also should add I'm talking about the capacitors for coupling purposes at audio frequencies.
Any other applications are indeed as you say.
D'haen and myself have hinted at that in this and probably other threads already.
In other words you subscribe to the same opinion.
"Malheureusement il faut casse des oeufs pour faire une ommelette,n'est-ce pas?"
Cheers,
Not a bad thing at all- I enjoy breaking those little white ovoids. And I can pass the basic test of a chef and make a proper omelette without using a spatula. It's getting damned difficult to find a proper omelette in France anymore; they cook them too long, in the American manner. I hope that they still do it the traditional way in Belgium.
Oh, yeah, capacitors. What was I saying? It's all so confusing.
Oh, yeah, capacitors. What was I saying? It's all so confusing.
Frank,
I am somewhat surprised. You say we should use the capacitors
that have the best specs according to the datasheets. Fine, but
you are quite inconsistent then, since in many other cases you
argue that components, wires etc, sound different even if this
cannot be explained in the datasheets. I am sure you do not
prefer the amplifier with the best tech. specs. (THD etc.).
I am somewhat surprised. You say we should use the capacitors
that have the best specs according to the datasheets. Fine, but
you are quite inconsistent then, since in many other cases you
argue that components, wires etc, sound different even if this
cannot be explained in the datasheets. I am sure you do not
prefer the amplifier with the best tech. specs. (THD etc.).
ON THE SURFACE
Hi,
Christer,
For coupling caps,definitely yes.
Assuming all other factors are equal the better dielectric would be preferable.
Not everything shown on a datasheet is related to the perceived sound.
However,when a datasheet shows frequency anomalies and other non-linear deviations from the ideal you can be pretty certain that this will have an impact on the perceived sound and measurements.
I've seen and heard many an amplifier with extremely good specs.
Unfortunately none impressed me sonically.
Which proves once again that measurements as we commonly use them are not al that meaningful.
And I repeat:for the amplifier as a whole.
Some measurements are more indicative than others,good slew rate behaviour is one of them,IMD is another indicator.
NFB is often overused to improve on the measurements.
Unfortunately it can also kill the sound in the process.
So,ask yourself which is better?
An amplifier that is optimized for good linearity and low distortion right from the outset by careful choice of building blocks or one that is carelessly designed with all possible tricks in the book added on so on paper at least it should look good?
The problem is that measurements are taken in a static way,music however is a very complex dynamic happening.
So,are we looking at the wrong figures ?
IMO,yes.
Hi,
Christer,
For coupling caps,definitely yes.
Assuming all other factors are equal the better dielectric would be preferable.
Not everything shown on a datasheet is related to the perceived sound.
However,when a datasheet shows frequency anomalies and other non-linear deviations from the ideal you can be pretty certain that this will have an impact on the perceived sound and measurements.
I've seen and heard many an amplifier with extremely good specs.
Unfortunately none impressed me sonically.
Which proves once again that measurements as we commonly use them are not al that meaningful.
And I repeat:for the amplifier as a whole.
Some measurements are more indicative than others,good slew rate behaviour is one of them,IMD is another indicator.
NFB is often overused to improve on the measurements.
Unfortunately it can also kill the sound in the process.
So,ask yourself which is better?
An amplifier that is optimized for good linearity and low distortion right from the outset by careful choice of building blocks or one that is carelessly designed with all possible tricks in the book added on so on paper at least it should look good?
The problem is that measurements are taken in a static way,music however is a very complex dynamic happening.
So,are we looking at the wrong figures ?
IMO,yes.
Re: ON THE SURFACE
But when it comes to capacitors you are just as certain that
we are looking at the right figures, which I think is somewhat
inconsistent. If you really are concerned about getting the
ultimate sound, it doesn't serve you to sit down and be
satisfied with such assumptions and think the matter is
settled beyond doubt. I cannot help sensing quite a bit of
psychology here, going by the datasheets when they they
"prove" your point, disregarding them when they don't.
fdegrove said:
But when it comes to capacitors you are just as certain that
we are looking at the right figures, which I think is somewhat
inconsistent. If you really are concerned about getting the
ultimate sound, it doesn't serve you to sit down and be
satisfied with such assumptions and think the matter is
settled beyond doubt. I cannot help sensing quite a bit of
psychology here, going by the datasheets when they they
"prove" your point, disregarding them when they don't.
PIECE DE RESISTANCE
Hi Christer,
Doesn't it all depend on how and what it is you read on a datasheet?
After all a datasheet is only an indicator of how and what it can be like in real life.
The trick is how you read it and draw your conclusions.
Your QQ and answers are so generalized I don't even know what exactly it is you're discussing here.
If there ever is one subject where one better not make gross generalizations it could well be audio.
Moreover I took great care as to provide a well defined context for my statement above.
All in all I get the impression this is all arguement for arguements' sake.
Cheers,
Hi Christer,
Doesn't it all depend on how and what it is you read on a datasheet?
After all a datasheet is only an indicator of how and what it can be like in real life.
The trick is how you read it and draw your conclusions.
Your QQ and answers are so generalized I don't even know what exactly it is you're discussing here.
If there ever is one subject where one better not make gross generalizations it could well be audio.
Moreover I took great care as to provide a well defined context for my statement above.
All in all I get the impression this is all arguement for arguements' sake.
Cheers,
Frank,
I have been somewhat sceptic regarding DA being responsible
for all the things that show up in SBs test, but I wanted some
time to sit down and think and read to confirm my suspicions
before going into that.
DA will cause an elliptical curve, which is nothing but a phase
shift and, thus, not a non-linearity. I cannot see how DA could
be responsible for the non-elliptical shape of the tantalum and
electrolytic curves, nor for the saturation effects shown for
ceramics, at least not according to any of the standard models
(the Dow model and the Cole&Cole model). Perhaps the
saturation could have something to do with DA if the caps
have time to get so hot that they reach the Curie temperature,
but that seems unlikely.
This also means that the voltage applied doesn't matter as
far as DA is concerned. The phase shift effect is independent
of voltage.
Maybe you see the point now of what I have said in recent
posts?
I have been somewhat sceptic regarding DA being responsible
for all the things that show up in SBs test, but I wanted some
time to sit down and think and read to confirm my suspicions
before going into that.
DA will cause an elliptical curve, which is nothing but a phase
shift and, thus, not a non-linearity. I cannot see how DA could
be responsible for the non-elliptical shape of the tantalum and
electrolytic curves, nor for the saturation effects shown for
ceramics, at least not according to any of the standard models
(the Dow model and the Cole&Cole model). Perhaps the
saturation could have something to do with DA if the caps
have time to get so hot that they reach the Curie temperature,
but that seems unlikely.
This also means that the voltage applied doesn't matter as
far as DA is concerned. The phase shift effect is independent
of voltage.
Maybe you see the point now of what I have said in recent
posts?
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