This might be of interest

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

--
Nick

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.

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.

d

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.



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.

d

Wonderfull bit of not seeming to want to listen Don. He said that as
well as causing a audible difference under blind testing, one of the
ways the effect can be demonstrated is that the caps produce sound.

There are more details here

http://www.icwltd.co.uk/claritycap/download/news2.pdf

--
Nick

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.


No, I listened again - I had it right.


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.

d

Wonderfull bit of not seeming to want to listen Don. He said that as
well as causing a audible difference under blind testing, one of the
ways the effect can be demonstrated is that the caps produce sound.

There are more details here

http://www.icwltd.co.uk/claritycap/download/news2.pdf


But which effect is being heard in the blind test? I note he didn't
claim double blind. And having read that paper, I can't say I'm too
impressed, apart of course from the obvious fact that Parameter 1 should
be C and Parameter 2 about 1.13. How could I not have known that already?

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

d

Don Pearce wrote:


But which effect is being heard in the blind test? I note he didn't
claim double blind.

What does ITU-R BS.1116-1 specify?

--
Nick

Nick Gorham wrote:
Don Pearce wrote:


But which effect is being heard in the blind test? I note he didn't
claim double blind.

What does ITU-R BS.1116-1 specify?


Something he can't possibly have done - a reference. That would be the
same speaker, but with no caps of any kind in it. And of course it would
have to be exactly the same speaker - the differences between two
samples of driver would be much bigger than what he is describing.

The BS.1116 system would let you listen to the reference, then each of
the two alternative capacitors and make your choice on which you prefer.


d

"Nick Gorham" wrote in message

Don Pearce wrote:


But which effect is being heard in the blind test? I
note he didn't claim double blind.

What does ITU-R BS.1116-1 specify?

Double blind.

"To conduct subjective assessments in the case of systems generating small
impairments, it is necessary to select an appropriate method. The
"double-blind triple-stimulus with hidden reference" method has been found
to be especially sensitive, stable and to permit accurate detection of small
impairments. Therefore, it should be used for this kind of test."

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.

I think the word you meant was FRAUD.

Graham

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.


There are more details here

http://www.icwltd.co.uk/claritycap/download/news2.pdf

I read the above, and then checked the company website. This has a PDF of
an EW article that says much the same. Since neither give much real detail
I've tried emailing to see if I can contact Paul Dodds. He is, apparently,
a 'Senior Engineer' with the company.


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

I may be able to come to a better conclusion when I've had more data. EG
from the refs given at the end of the above PDF document.

But FWIW I gave up reading EW some years ago as it seemed to become full of
publicity material masquerading as technical articles. This happened when
EW stopped paying for submissions, and is the obvious consequence of such a
course. However my Uni Library still get EW, so I'll also have a look when
I get a chance to see if there has been any reaction in the form of
letters, etc.

I also went to the Salford Uni site, but the only link there I found for
the co-worker gave a 404.

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.

Interesting, though... :-)

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

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