Capacitor types for best audio performance

[chriswood1900]

Ed
Were these the items you were referring to?
https://linearaudio.nl/cyril-bateman...sound-articles
Chris

[Radio Wrangler]

Thanks, Chris, those make brilliant reading. Seen together they are quite dramatic. Some of it I already knew, A lot I didn't.

It only leaves the minefield of what can a human ear discriminate left to argue over

David

[GrimJosef]

Originally Posted by Radio Wrangler

... It only leaves the minefield of what can a human ear discriminate left to argue over ...

Sadly it's more messy even than that . Two other factors which matter to audiophiles are

1. Is any testing being carried out under realistic conditions ? In the real world people generally listen to their hi-fi at home. They might well have spent hours or days refining their speaker positions. I knew a chap who had his record deck in an adjacent room to avoid acoustic feedback. They care about whether the tonal idiosyncracies of their record cartridge complement those of their speakers. They choose their music to suit their mood. They often say that their ability to discriminate is at its best when they're relaxed and when they can listen to music they've chosen for relatively short periods spread over several days or even weeks. They dismiss any inability to pass tests as being due to faulty tests. It's hard to argue against that.

2. What are we trying to achieve ? Is the point to make an audio system which measures best or which sounds best. If you suggest to audiophiles that the measurement is what matters then you can expect to be laughed off the stage. (There is a more subtle point about whether two systems which measure the same can sound different, but a lot of audiophiles quickly become bored with that debate. Life's too short.) I believe that when proper tests were done people actually preferred their music to have had a little bit of second harmonic distortion added (they said it gave it a 'sweeter' tone). So those of us who are pursuing the perfect capacitor might actually be barking up completely the wrong tree.

Cheers,

GJ

[mark_in_manc]

Originally Posted by Radio Wrangler

Terry Pratchett coined the word 'Headology'

The difference between audiophile and non-audiophile parts lies not in the capacitors themselves but in the audiophiles. Mark's friend was looking in the wrong place.

That's true. When we were involved (whisper it - with various projects concerned with the manufacture of _products_ ) the ktp scheme was so broad and (compared to EPSRC) generous, that something entitled 'Headology: gourmets, ego and the manufacture of brand value' might well have been funded. Alas, our lack of track record in social science research would probably have caused it to be rejected, if we had been the ones to submit it

[Radio Wrangler]

The context of " It only leaves the minefield of what can a human ear discriminate left to argue over" was whether differences in capacitors would be audible. Sorry, I should have been clearer. I wasn't considering whether those differences, where audible, might be preferable.

As far as I'm concerned, audiophiles are quite free to change whatever they fancy in order to adjust the sound they get to their preference. I happen to think that they sometimes might be able to do this more easily and more affordably by making controlled changes to say the frequency response or equalisation rather than by repeatedly swapping some expensive piece of equipment. But it's their money and time and it seems to make them happy.

Where I do feel things are wrong is when they make absolute statements of what is right or wrong, accurate or inaccurate, when they are really talking about personal taste and personal preferences.

I find it a good laugh to read some of the pseudoscience trotted out in attempts to justify personal preferences. Preferences do not require justification. Any half-assed science just acts as a distraction and feeds ammunition to critics. Just stick to 'I prefer the Gogomophon GGXLR-1 'Valkyrie Black' cartridge' without invented technical embellishment and the statement is unassailable. The moment science gets invoked then people can ask awkward questions about whether the tests are repeatable, and repeatable by all other testers.

Cyril Bateman did excellent work and it includes some interesting insights into capacitor manufacturing issues. I have little doubt that his work could be redone with similar results. My curiosity is now over how big do each of these effects need to be before they cross the threshold of perception? and maybe 'did he find all the significant effects?'

David

[Craig Sawyers]

Back in the 1970's, HiFi News used only to measure audio equipment, and never listened to it. Which is in hindsight pretty daft.

It gave good reviews for example to an Ortofon phono stage for moving coil cartridges. This had an array of high capacitance tantalum bead capacitors in parallel as a DC block between the cartridge and the amp. Tant beads give lousy distortion, easily measured (see Bateman's articles). Back to back electrolytics, or a non-polar electrolytic would have been much more sensible.

But then again, talking to the late great Mike Albinson at Quad, they never actually listened to their electronics products. They designed them, tested them, and went straight to manufacture. "Don't you have an audio system at home, and hence listen to Quad gear" "Good heavens no" he said "Far more interested in classic motor bikes".

Although I am an electronics engineer by training and background, I tend to subscribe to the Linn philosophy "If it sounds good, then it is good". Design, build, test, listen.

Craig

[Craig Sawyers]

Originally Posted by Radio Wrangler

Cyril Bateman did excellent work and it includes some interesting insights into capacitor manufacturing issues. I have little doubt that his work could be redone with similar results.
David

He did. In Linear Audio V9, April 2015, pp 149-170. With somewhat depressing results regarding product variability and changes in construction and manufacture. Particularly of film capacitors, which are now pretty much all made in China, which has all happened since the original early 2000's articles.

It was published not long before he died.

Craig

[stevehertz]

Here's 'my' conclusion. Different types of capacitors do behave differently in an audio signal path. They all give rise to, and some more than others, directly or otherwise, very low amounts of distortion. For the audio enthusiast, the salient point is, these distortion levels are exceedingly low and quite possibly undetectable in ABX testing.

Thanks everyone for your input, although I'm sure this thread is not over yet.

[Ed_Dinning]

Hi Chris, yes that was his articles. I've not got access to my WW archive at present but there may be one more.

Ed

[PJL]

Originally Posted by kalee20

Crossover networks are one place where 'capacitor sound' could arguably kick in! Significant current flowing, appreciable voltage across the capacitor - non-linearities would be easily measurable there.

Any reputable capacitor manufacturer making products for this application could easily put forward a valid technical argument, and optimise their offerings appropriately.

But the capacitor contribution will still be minuscule compared to the distortion introduced by even the most exotic speaker drivers.

[Radio Wrangler]

Originally Posted by PJL

.... by even the most exotic speaker drivers.

and the goldenest of ears...

David

[Argus25]

There is a thought experiment that proves any real capacitor is imperfect.

If you have an imaginary perfect dc power supply voltage V with a source impedance of zero ohms and you connect a capacitor across it the capacitor will charge up quickly to the supply voltage . The work done by the supply is VQ, where Q is the charge that has passed by the supply terminals. However, the energy stored in the capacitor is only VQ/2, so half the total energy is lost. It is lost in the internal resistance of the conductors and connections that make up the capacitor, some tiny amount probably gets radiated as EM waves from the inductance and some as dielectric losses.

[Radio Wrangler]

If you do the same thought experiment with zero resistance wire and zero ESR capacitor, the whole of the missing half of the energy has to be radiated.

If the source and capacitor are not in the same place, the loop length cannot be zero, so inductance rears its head, and there is ringing, damped by radiation resistance and any real resistance in the conductors.

It's a very telling thought experiment!

David

[G8HQP Dave]

Yes, even a perfect capacitor only ends up with half of the energy. The other half eventually ends up as heat somewhere, either in the components and wires or in the far reaches of the universe (unless the radiation gets absorbed nearby).