About film caps http://members.aol.com/sbench102/caps.html

" On close inspection the 'curves' for some of the film caps look like they're slightly elliptical but I wasn't wholly convinced by the test method ( gut feeling ).

I was puzzling over this and then the answer dawned. The test method is completely flawed."

Please explain how this test method "completely flawed?"

Steve Bench said,

"The "X" input to the scope was fed with an additional series capacitor and adjusted for exactly "90 degrees" phase shift (typically ran 0.01u into the 10 meg scope probe resistance) to reduce systemic errors."

I assume that after calibrating his scope that he did not change it during a set of capacitor measurements. If that is true, these measurements at least show a difference among film capacitors.

Joe

Not that simple.

The cap was in series with a sampling resistor in order to display the current.

As a result, normal variations in capacitance value as a result of tolerance would indeed give rise to small phase angle errors and that in turn will result in a lissajous loop.

Graham

Is that your answer to my question, 'Please explain how this test method is "completely flawed?" ?'

Joe

Essentially, yes it is.

It relies on the operator. The very slight ellipsis I see for some of the plastic film caps *must* be a phase error. At least it's indistinguishable from a phase error and hence the result is meaningless.

Look at the result for the ceramics and see what dielectric non-linearity *should* look like.

Graham

If all your assumptions are correct.

All tests do. Instruments don't calibrate themselves nor set themselves up.

Why? Because that's what you want it to be?

It's only 'indistinguishable' because you insist on claiming he did the test improperly when there aren't enough details provided to draw that conclusion.

They were very carefully thought through. This wasn't some quick "off the cuff" idea.

The modern stuff does though !

Because that's what a phase error does to a lissajous figure.

If the result is identical to a phase angle error then it's reasonable to believe it *is* a phase angle error !

It's certainly *not* a variation in dielectric coefficient with applied voltage since that must pass through the same origin by definition.

Graham

They're still assumptions and apparently based on your firm belief that what's shown can't be so you're willing to assume whatever it takes to fit, except that his experiment is valid.

It's just further removed from the end user but until the things start birthing themselves it still boils back to the human.

Prove that nothing else in the world could create such a figure and you might have a point.

Only if nothing else in the world can product the same result.

I said dielectric absorption, not "variation in dielectric coefficient with applied voltage."

No more assumption than the site owner's ones.

If the model fits, it *IS* valid.

Obfuscation.

An ellipse on a lissajous display is the very definition of phase angle !

I'm not aware of any other.

DA isn't non-linear, and if it's DA it's of no interest wrt distortion. Variation of K with applied voltage does however create distortion.

Graham

You haven't got the slightest idea what, if any, his 'assumptions' were, which makes that claim another assumption.

Except you have no way whatsoever to verify whether your assumptions 'fit'.

No, it's just true. I have yet to see an experiment create and conduct itself. There's always a human in there somewhere.

I repeat, unless you can prove nothing else in the word can put a trace like that on an oscilloscope you haven't proved your assumption.

Are you claiming omniscience?

I don't know how you can claim that.

From first principles.

The model for DA ( which works ) contains only linear components. Ergo DA doesn't introduce non-linearity. It's that simple.

Nor does DF introduce any non-linearity either for the same reason.

Graham

The 'first principle' is that 'distortion' is any deviation from the original.

So a non-uniform frequency response is distortion ?

Graham

Formal name: linear distortion.

"Distortion comes in two basic classes: Linear distortion, which is not an oxymoron; and nonlinear distortion, which includes all other distortions except noise. Noise is quite another matter and is not covered here. "

Sure, I'm aware of the definition but I think it's disingenuous to use it here.

Most ppl I know of are referring to harmonic distortion when using the term.

Graham

I agree that Flipper is abusing it.

That, or IM.

That's an amusing claim in response to your own posting of 'linear distortion'.

The 'problem' is Eeyore wants to argue 'proof by semantics' but the issue is whether different capacitor types (audibly) 'affect' the resulting sound, not whether the mechanism (if there is one) fits Eeyore's presumption of what the 'only possible cause' could be (with everything else "of no interest).

His logic goes 'only non linear distortion can affect the sound ergo there's no effect to changing capacitor types'. It's a non sequitur because the premise has been shown to be suspect by the 'linear distortion' example.

And that's the 'semantics' of it. For the sake of discussion let's assume the statement is true (as well as his claim there's no non linearity). I.E. that that's what "most people mean." It still doesn't 'prove' that the 'sound' is not altered, only that it may be altered by a mechanism (linear distortion having been presented as one possibility) different than what Eeyore wants to declare is the only possible means. Or, put another way, he's trying to argue that since the effect doesn't fit what, as he puts it, "most ppl I know of are referring to" then it 'can not alter the sound'.

It's clearly untrue when one puts it in the context of the actual issue as all manner of things, besides 'distortion' as he wants to define it (only non linear), can 'affect the sound' and that's why I put 'distortion' in the basic sense of the word; because whether the 'sound altering' mechanism fits into a semantic cubbyhole is not the question at hand..

Even the above doesn't address that there may be an unidentified mechanism as well. Or, as argued, it could be smoke and mirrors but you can't 'prove' that with semantics.

You don't get it. I posted it, you abused it.

No, the issue is whether the kind of gratuitous capacitor upgrades that self-aggrandizing snake oil artists like Jute proclaim, are actually sonically effective.

Of course the wrong capacitor in the wrong application can cause otherwise good equipment to sound bad.

Obviously, capacitor technology has improved a lot in the past 100 or so years.

Certainly, defective parts can hurt sound quality.

Of course, if bragging rights are what you want, parts made of the highest grade of unobtanium, and priced accordingly will give you bragging rights.

Finally, if audio jewelry is what you want, then these caps over here with cases made of hand-carved and lovingly lacqueored ebony with inset ivory polarity markings and gold inlaid engraved parts identification information are exactly what you want.

We mostly address problems with linear distortion due to capacitor dielectrics by using capacitors with the right amount of capacitance.

No joke, lots of people meet the physical challenge of replacing electrolytics with film caps by dramatically cutting capacitance. On occasion, I've seen this lead to audible variations in frequency response, particularly at the bottom end.

That impresses only young boys and visiting firemen who don't under the true meaning of linear distortion.

Arny "I spoke in error" Krueger once more spoke in error:

Yo, Krueger, you're a liar.

Show one instance where I "proclaimed" or even suggested a capacitor upgrade. If you can't, you're a liar.

Show one instance where I "proclaimed" or even suggested a "gratuitous" capacitor alteration of any kind. If you can't, you're a liar.

You're such a disgusting little man, Arny Krueger, in every sense of the word, that your lies hardly adds to the contempt in which we already hold you.

Andre Jute Our legislators managed to criminalize fox-hunting and smoking; when they will get off their collective fat arse and criminalize negative feedback? It is clearly consumed only by undesirables.

So, Arny Krueger, will you attempt to prove these lies you told about me in an effort to aggrandize your insignificant self, or do you accept that once more you have been exposed as a liar and a disgusting little man?

You stated as facts certain matters which are not true. You must prove them or forsake all claim to scientific credibility.

In addition, you must apologize for bearing false witness about me or forsake all claim to Christian decency.

Andre Jute This is the seas> Arny "I spoke in error" Krueger once more spoke in error: