different type caps sound different?

[R.G.]

... And what is it's capacitance at that frequency?...
See this page and read the notes. Capacitor Frequency Response (interfacebus)
(Just more fuek for the fire)

More fuek for the fire, indeed.

One interesting thing about the internet is that anyone can say anything, and if it's sufficiently pseudotechnically said, it is taken by some readers as the verifiable truth.

In this case the statement:

Different types of capacitors using different types of dielectrics are only able to operate within a particular frequency range.
The graph shows the different styles of dielectrics and their operational frequency range.

The displayed graph asserts some things that all of my professional training and experience says is nonsense, or at best a partial truth. For instance:
Glass is shown as unusable as a dielectric below 1kHz and then only with special processing and design; "normal" glass dielectric caps are indicated as unusable below 100kHz. Unless there is a lot of unstated qualifiers hidden behind that chart about what "able to operate" means, that's flatly false.

I personally have constructed glass dielectric caps from glass plate and aluminum foil as a part of my teenage tinkering with potentially-deadly high voltages. I can report from painful personal experience that glass caps work fine at DC, holding a huge charge for days, just as a capacitor should. On the more professional side of things, the gate of a MOSFET is essentially very pure glass, and it acts like a capacitor from DC to well into GHz. The creator of that chart needs to make clear what he means by "able to operate".

Then there's tantalum, shown as not usable above (squinting...) about 200Hz without special processing? Tantalum is used in power supplies precisely because it has a better high frequency response than most aluminum caps. I guess that the "special processing" cutout does show it going out to nearly 100MHz, but then I suppose that maybe *all commercial tantalums* may be "specially designed and processed".

There are more places where that chart, without any refinement or qualification, is in opposition to my experience. I guess my response is summed up by Alexander Pope (1688 - 1744) in An Essay on Criticism, 1709:

A little learning is a dangerous thing; drink deep, or taste not the Pierian spring: there shallow draughts intoxicate the brain, and drinking largely sobers us again.

and, from me, to the maker of the chart:
So you say. OK, get out your data and prove it.

I admit the possibility that my training and experience is incomplete or incorrect; however, the incidentals of this body of information has always served me well before. And the burden of proof is always on the one who makes the assertion, in this case, that chart.

[m-fine]

we have one side describing an observation and another claiming that observation cannot be possible. The latter is operating on a faith-based premise "I know of no physical characteristic which would explain this phenomenon therefore it must not have happened."

The lack of a theory to explain an observation does not negate that observation.

We have one side relying on experience and hundreds of years of science and engineering, and another side offering an unverified observation that has not been independently tested and verified and that was not made under controlled conditions.

If someone were to say they saw a stream flow up a hill, those who have experience with water running down hills and knowledge of gravity, would quickly dismiss the claim and say there was something else going on that caused the person to make the observation they did.

Caps absolutely have real measurable differences. In a high resolution audio system that plays several octaves above a typical guitar, there can be subtle audible differences as well. In a typical guitar system, any audible difference BETWEEN TWO NON-DEFECTIVE CAPS THAT MEASURE TO THE SAME CAPACITANCE is going to be extremely small, and difficult if not impossible to detect in a double blind test. Go ahead and try it. If the difference is night and day, where one amp sounds great and the other sounds bad, there is something else going on.

One more comment. A cap can test well at a couple of volts and still not behave properly at 450 volts. So, just because caps test OK and measure close to the rated capacitance on a typical low volt ebay tester, does not mean they are not malfunctioning at high voltages in the amp.

[R.G.]

...
The lack of a theory to explain an observation does not negate that observation.

You're correct.

However, there is a competing observation. It has been observed repeatably and under reliable, recreatable conditions that the human mind is an unreliable observer. Ask a policeman or lawyer how reliable eyewitnesses are. Ask a research psychologist. Ask a stage magician. Ask a hypnotist.

Special note to daz: this is not implying the placebo effect. It is only exactly what the words say.

Here's the deal: there are many possible explanations for an observation of a situation being at odds with the body of scientific knowledge. Some of these are that we don't yet know all the rules for how the universe works.

As examples, Albert Einstein produced some thought experiments that explained more accurately how the universe really works than any preceeding theory. His modifications to the earlier theory showed not only what happened at extreme conditions, but why we can't see the difference until conditions get extreme.

Quantum physics were a refinement of the earlier understanding of natural law. Einstein, with all his mental prowess refused to believe it despite verifiable, repeatable proof of how it works. People can be wrong, even smart ones, and they can refuse to believe the observations.

When one person makes an observation that flies in the face of the preceding body of scientific knowledge, it's possible that they are the first observer of something really, really new. It's also possible that they are mistaken, or have come up with an incorrect interpretation of the cause of the event. Sorting out which of the possibilities is real is the reason you repeat observations. If something is a real effect of the external physical universe, it will be (at least potentially!) repeatable.

If it's not repeatably observable by independent observers, then there is real reason to question whether the event is special, or the observer.

And in fact, that last sentence is reliably repeatable and observable by independent observers.

The burden of proof is on the person who asserts that the universe is really different than everybody thought. If it's real, it's repeatable and observable by *any* disinterested observer, not limited to true believers.

[trem]

My "problem" with guys and their different coupling caps is the video presented by "EELP89". That video is exactly the difference I hear in same value Orange, Yellow, Blue, Mallory, Vishay, Sozo, or whatever caps may be in a circuit. That is to say I don't hear a difference. I have been involved with music for a long time, and I think I have a decent ear. So it is real hard for me to believe that, while I hear no difference, other guys are hearing, "articulation", "boomy low end", "more pronounced mids", "harsh high end", "much more clear high end", "much better in the low mids", and a bunch of other descriptives; just because they went from a IC .033 mF cap to a Orange Drop .033 mF cap. You mean to tell me they can hear all of that, and I can hear nothing.???
Some of these guys hear as much change in a brand of cap as I do in going from a EV 12L speaker to a Celsestion "GreenBack" speaker. Just real hard for me to believe....I'm Sorry.

[EELP89]

it was brought to my attention that youtube is known for bad audio compression and the speakers you listen to this clip on matter. which makes perfect sense.

on the other forum i posted this on, many people heard differences on the clip while others didn't. but everyone said they had converted to PIO and were happy. so,

i will just have to purchase some and try it out myself and report back.

is there anyone out there who HAS changed to polypropylene or PIO and NOT noticed a difference?

[Groover]

Now that is a good question!

[jmaf]

> is there anyone out there who HAS changed to polypropylene or PIO and NOT noticed a difference?

We bought a case of old Brazilian oil caps made in the 70's from a store that was closing and we tested several combinations of them as coupling caps and tone caps on a bench test amp. We noticed big changes between the vintage oil caps and chinese polyester and even better quality caps such as red WIMA rectangular types(polystirene?). I never had the time to study what exactly was changed, but the old oil ones had "fatter" sound, some even dampened sound, probably skewed from the original specs. Many were leaky, we threw a bunch of them out, but the ones that survived our tests were employed on some prototypes and they sound great.

Their imperfections surely shaped the tone and it led us to the same conclusions the more veteran members already mentioned: perfect caps all should sound the same. Choose the imperfection that suits you best, which you or your customers like the most. And I guess I'm just stating the obvious....

[Steve Conner]

it was brought to my attention that youtube is known for bad audio compression and the speakers you listen to this clip on matter. which makes perfect sense.

This is absolutely true. If you have a less compressed version of the soundtrack of that video, please go ahead and post it here. Something like FLAC, or MP3 at 192kbit or greater.

I don't know about the rest of you guys, but my computer is hooked up to a 24-bit Focusrite DAC, a 30 watt per channel tube amp, and a pair of Dynaudio nearfield monitors. So I can really hear how bad Youtube sucks.

Choose the imperfection that suits you best, which you or your customers like the most.

I like this way of putting it, but I'd add the following caution: How do you know the imperfection is going to stay the way you like it? Those PIO caps probably sound the way they do because they've degraded with age, and they're going to keep on degrading. In EE school, we were taught never to rely on any property of a component that isn't specified in the datasheet, because there's no guarantee that it'll stay the way that makes your circuit work.

[jmaf]

I like this way of putting it, but I'd add the following caution: How do you know the imperfection is going to stay the way you like it? Those PIO caps probably sound the way they do because they've degraded with age, and they're going to keep on degrading. In EE school, we were taught never to rely on any property of a component that isn't specified in the datasheet, because there's no guarantee that it'll stay the way that makes your circuit work.

Steve, you went straight to our conclusion(and it took us a few days longer to arriva at ). Several of those oil caps developed leakage after a few days burn-in. We used them in prototypes and tests and whatever degradation they had made them sound incredible. We measure them in DC and the values are very approximate to specs, like I said we didn't study what happened once HT was applied....or what is happening to the waveform through them....it was mostly all about the ear test.

While we're at it: Is there anything we can do to this lot to make them more reliable? Cook them, leave them in low voltage for a month, etc? They sound great, it'd be nice if we could save them.

[Steve Conner]

No, I don't think there is any way to stabilise them.

I'd bet that the effect you like is caused by some parasitic resistance. Either high ESR, or low shunt leakage resistance, or both.

So I'd measure those parameters from the good-sounding capacitors, and then add resistors of the same values to a modern capacitor, which would hopefully give the same tone. If it didn't, I'd get out the audio spectrum analyzer and start looking for some sort of non-linearities in them.

[Ronsonic]

I respect Steve's decision to ignore what he finds to be unimportant. This is too large a subject to waste time and if his gear is sounding good, I'm not going to argue with results.

It's an interesting discussion and always good to hear what the guy on the other side of the elephant thinks he's discovered. Ultimately we will all go back to our benches and working with the reality as we find it there.

Perception:

YouTube - What is your hazard perception like ? take the test

[jmaf]

I'd bet that the effect you like is caused by some parasitic resistance. Either high ESR, or low shunt leakage resistance, or both. |...| I'd get out the audio spectrum analyzer and start looking for some sort of non-linearities in them.

Yes, thanks. Like I said, nothing ellaborate was done. In fact, they're lying around in a box somewhere, this topic reminded me of them, trying to find out what makes them special oughta be after-hours fun sometime.

[Wilder Amplification]

In EE school, we were taught never to rely on any property of a component that isn't specified in the datasheet, because there's no guarantee that it'll stay the way that makes your circuit work.

Which is one thing that Joey Voltage swears by (not putting your tone at the mercy of a particular component's unpredictable traits). Although one must remember that in practical electronics there are no absolutes and just because it bears a certain spec on paper, there's still no 100% guarantee that the on paper specs will always hold true from one component to the next, unless it's some ungodly close tolerance component, and that's where things get to the point of "Does it really matter?".

Then you get into the group of people who are under the impression that if there's a measurable difference in component specs then the human ear can always hear it. In the experience of most of my personal observations it seems that you never hear any of this talk of "magic mojo" coming from well seasoned players (with the exception of Eric Johnson of course ). I'm not sure if this holds true in all cases but in my observations it seems to hold up in most.

If there's one motto I live by it is that practice cures most tonal woes.

[tedmich]

....In the experience of most of my personal observations it seems that you never hear any of this talk of "magic mojo" coming from well seasoned players (with the exception of Eric Johnson of course ).

Someone posted a discussion with a tech EJ had a few years back where he went on and on about the tone afforded by the brass fasterners on the back of his favorite overdrive pedal,


quite possibly apocryphal but it made me laugh...

"feelings" are the quickest route to most peoples wallets IME

[Groover]

If there's one motto I live by it is that practice cures most tonal woes.

NOOOOO!! That is far too wise and logical to be allowed on this forum!