On 2008-08-22, Jim Lesurf wrote:
In article , Don Pearce
wrote:
Nick Gorham wrote:
Don Pearce wrote:
Nick Gorham wrote:
This might be of interest
http://www.sonicstate.com/news/shownews.cfm?newsid=6667

No, I listened again - I had it right.

I presume the above URL sends a 'stream' of some kind. My browser simply
tells me that it doesn't have a Flash plugin enabled and the page text
seems void of info.

Yes - you need a plug-in. I found it interesting for what he says
does NOT matter with respect to the vibration and resonance effects
he describes.

- The capacitor's vibration of which he talks is not caused by the
opposing currents flowing in the parallel plates [1].

- The vibration is connected with the voltage appearing across the
capacitor but it does not seem to be discernible at voltages less
than 12V. (That cuts out any problem to do with an effective coupling
capacitor).

- It's apparently nothing to do with tan delta (loss), the effective
series resistance (ESR) or the capacitance (the nominal value I assume).

- The reverse effect where a (very) high-level audio signal impinges on
the capacitor seems to produce no discernable result (an output voltage,
I assume). So much for capacitor microphony claims.


[1] I did the analysis of this effect some years ago for loudspeaker
cables and derived expressions for how the capacitance and inductance of
zip-cord speaker cable varied with current flow. The coefficients (of
dependence on the square of the current) in typical cases were in the 1-10
parts per billion range, IIRC. I decided they were too small to matter.

--
John Phillips

In article , John Phillips
wrote:
On 2008-08-22, Jim Lesurf wrote:


[1] I did the analysis of this effect some years ago for loudspeaker
cables and derived expressions for how the capacitance and inductance of
zip-cord speaker cable varied with current flow. The coefficients (of
dependence on the square of the current) in typical cases were in the
1-10 parts per billion range, IIRC. I decided they were too small to
matter.

WRT The ClarityCap papers I've not yet seen any figures for the SPL
generated for a given input voltage. So no idea how loud the results may
be. The paper also mentions doubling - which is what you'd expect if the
mechanical movements are due to the force between the plates caused by the
charges on them.

Slainte,

Jim

--
Change 'noise' to 'jcgl' if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf wrote:
In article , John Phillips
wrote:
On 2008-08-22, Jim Lesurf wrote:


[1] I did the analysis of this effect some years ago for loudspeaker
cables and derived expressions for how the capacitance and inductance of
zip-cord speaker cable varied with current flow. The coefficients (of
dependence on the square of the current) in typical cases were in the
1-10 parts per billion range, IIRC. I decided they were too small to
matter.

WRT The ClarityCap papers I've not yet seen any figures for the SPL
generated for a given input voltage. So no idea how loud the results may
be. The paper also mentions doubling - which is what you'd expect if the
mechanical movements are due to the force between the plates caused by the
charges on them.

Slainte,

Jim


While we're at that, lets not forget the racket that ferrite cored
chokes make in crossovers through magnetostriction. I know that decent
speakers use air-cored coils, but I've even heard those singing on occasion.

d

Jim Lesurf wrote:

So far as I can recall, it isn't 'news' that caps can have mechanical
resonances. The claim that is interesting is that they are audible. But to
decide, I'd need to know a lot more about how the 'results' were obtained.
For reasons like those others have already mentioned.

Crappy quality ones (electrolytics at least) can be bad. I've come across some.
Doesn't mean you have to use magic dust or incantations to fix it though, just
buy well-made quality product.

Graham

John Phillips wrote:

- The vibration is connected with the voltage appearing across the
capacitor but it does not seem to be discernible at voltages less
than 12V. (That cuts out any problem to do with an effective coupling
capacitor).

Well I'm glad we disposed of 99.99999% of the problem in one hit there then.

Is some twit now going to suggest it makes a difference for PSU reservoir caps
?

Graham

John Phillips wrote:

[1] I did the analysis of this effect some years ago for loudspeaker
cables and derived expressions for how the capacitance and inductance of
zip-cord speaker cable varied with current flow. The coefficients (of
dependence on the square of the current) in typical cases were in the 1-10
parts per billion range, IIRC. I decided they were too small to matter.

-180 dB is indeed pretty irrelevant.

Graham

Nick Gorham wrote:

Don Pearce wrote:
Nick Gorham wrote:

This might be of interest

http://www.sonicstate.com/news/shownews.cfm?newsid=6667


He dropped some rather interesting info when he was talking about the
blind testing "70% of the people in most of the tests preferred our
capacitors". It is the word "most" that is telling. Suppose by most he
meant perhaps as many as 70%.... Then just under half of the people
tested would have preferred his caps.

Well, I head it as the fact that in blind tests most people prefered the
low resonance caps (ie more than 50%), and in some tests up to 70%
prefered them.

WTF is a 'low resonance cap' other than audiophool bull**** ?

Graham

Don Pearce wrote:

Please don't be too impressed by this. When someone passes off an advert
as an academic paper, you really must smell a rat.

You mean a fraud of course.

Graham

Don Pearce wrote:

He is also talking about something rather different than most people
when considering the sound of the capacitor - he is talking literally;
the capacitor is physically making sounds. All you need to do is pop it
in a box, and you won't hear it.

You mean like a box poly capacitor ?

Graham

"Jim Lesurf" wrote in message
...

I presume the above URL sends a 'stream' of some kind. My browser simply
tells me that it doesn't have a Flash plugin enabled and the page text
seems void of info.


To be honest it was an 11 min clip that was plenty of waffle,
related by a poor chap who looked uncomfortable and not at
ease being filmed though he certainly knew his onions.
But it has to be said the clip was of impressively high resolution
and the sound was OK too.