Do all capacitors sound the same.
 

On 2008-08-22, 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.

Yes. IIRC, the interview also reveals that the voltage-driven (charge-
driven) vibration in the capacitors is second harmonic, and that this
is as would be expected.

--
John Phillips

Do all capacitors sound the same.
 

John Phillips wrote:

Jim Lesurf wrote:
John Phillips wrote:
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.

Yes. IIRC, the interview also reveals that the voltage-driven (charge-
driven) vibration in the capacitors is second harmonic, and that this
is as would be expected.

Come to think of it, yes it would.

Now show me a decent 'name brand' commercial quality capacitor that actually
does make any noise.

Graham

Do all capacitors sound the same.
 

Nick Gorham wrote:

This might be of interest

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

I see no-one's actually interested in the truth. It might be a wee bit
too technical for them.

Graham

Do all capacitors sound the same.
 

Eeyore wrote:

John Phillips wrote:


Jim Lesurf wrote:

John Phillips wrote:

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.

Yes. IIRC, the interview also reveals that the voltage-driven (charge-
driven) vibration in the capacitors is second harmonic, and that this
is as would be expected.


Come to think of it, yes it would.

Now show me a decent 'name brand' commercial quality capacitor that actually
does make any noise.

Graham


I just tried the experiment on a few caps I have to hand. The ones that
produces a sound when driven by a sig gen were a BC 368WKT 220nf,
Acotronics MKP 47nf and a 2.2uf ClarityCap SA. Ones that I tried that
didn't prduce any sound I could hear were from Solen and Mundorf.

Not sure what you refer to as a 'name brand' but I would think at least
the BC would fit that decsription.

Though as expected the level was very low, at the 2vRMS 5kHz from my sig
gen, it needed the cap to be against the ear, but it was clearly there.

--
Nick

Do all capacitors sound the same.
 

Nick Gorham wrote:

Eeyore wrote:
John Phillips wrote:
Jim Lesurf wrote:
John Phillips wrote:
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.

Yes. IIRC, the interview also reveals that the voltage-driven (charge-
driven) vibration in the capacitors is second harmonic, and that this
is as would be expected.

Come to think of it, yes it would.

Now show me a decent 'name brand' commercial quality capacitor that actually
does make any noise.

I just tried the experiment on a few caps I have to hand. The ones that
produces a sound when driven by a sig gen were a BC 368WKT 220nf,
Acotronics MKP 47nf and a 2.2uf ClarityCap SA. Ones that I tried that
didn't prduce any sound I could hear were from Solen and Mundorf.

What was your drive signal ?


Not sure what you refer to as a 'name brand' but I would think at least
the BC would fit that decsription.

Yes, generally so. It's Vishay BC too now just for more fun.


Though as expected the level was very low, at the 2vRMS 5kHz from my sig
gen, it needed the cap to be against the ear, but it was clearly there.

That close ? Care to estimate the dB @ 1m ? It's hardly like inductors singing is
it ?

Oh and the 368 isn't a 'box poly'. Try one with the plastic box construction next.
You know the type I mean ?

Graham

Do all capacitors sound the same.
 

Eeyore wrote:


Nick Gorham wrote:


Eeyore wrote:

John Phillips wrote:

Jim Lesurf wrote:

John Phillips wrote:

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.

Yes. IIRC, the interview also reveals that the voltage-driven (charge-
driven) vibration in the capacitors is second harmonic, and that this
is as would be expected.

Come to think of it, yes it would.

Now show me a decent 'name brand' commercial quality capacitor that actually
does make any noise.

I just tried the experiment on a few caps I have to hand. The ones that
produces a sound when driven by a sig gen were a BC 368WKT 220nf,
Acotronics MKP 47nf and a 2.2uf ClarityCap SA. Ones that I tried that
didn't prduce any sound I could hear were from Solen and Mundorf.


What was your drive signal ?

The voltage across the cap was (as I said) 2v rms from a Farnell sig gen.



Not sure what you refer to as a 'name brand' but I would think at least
the BC would fit that decsription.


Yes, generally so. It's Vishay BC too now just for more fun.



Though as expected the level was very low, at the 2vRMS 5kHz from my sig
gen, it needed the cap to be against the ear, but it was clearly there.


That close ? Care to estimate the dB @ 1m ? It's hardly like inductors singing is
it ?

I never said it was, I have no point to prove or axe to grind here, but
as you asked:

"Now show me a decent 'name brand' commercial quality capacitor that
actually does make any noise."

I think the important point in terms of the level of the signal and
sound was you asked for "any".

I thought it would be interesting to actually try some caps instead of
making assumptions.


Oh and the 368 isn't a 'box poly'. Try one with the plastic box construction next.
You know the type I mean ?


Yes, as I said, it was just the ones that came to hand, and as I said,
some others didn't, but you asked for "a" "name brand", so I found one
for you.

--
Nick

Do all capacitors sound the same.
 

In article , Nick Gorham
wrote:


I just tried the experiment on a few caps I have to hand. The ones that
produces a sound when driven by a sig gen were a BC 368WKT 220nf,
Acotronics MKP 47nf and a 2.2uf ClarityCap SA. Ones that I tried that
didn't prduce any sound I could hear were from Solen and Mundorf.

Not sure what you refer to as a 'name brand' but I would think at least
the BC would fit that decsription.

Though as expected the level was very low, at the 2vRMS 5kHz from my sig
gen, it needed the cap to be against the ear, but it was clearly there.

What is the o/p impedance of your sig gen? 2.2microF at 5kHz is about 15
Ohms if my fingers just pressed the correct buttons on my hand calculator.
Implies a reactive level of over a Watt if you really were applying 5v rms.

If I understand the ClarityCap papers correctly, you'd need to find the
mechanical resonance of each cap to get a peak level of vibration. So 5k
might not give as large a response as some other frequency.

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

Do all capacitors sound the same.
 

Jim Lesurf wrote:
In article , Nick Gorham
wrote:



I just tried the experiment on a few caps I have to hand. The ones that
produces a sound when driven by a sig gen were a BC 368WKT 220nf,
Acotronics MKP 47nf and a 2.2uf ClarityCap SA. Ones that I tried that
didn't prduce any sound I could hear were from Solen and Mundorf.


Not sure what you refer to as a 'name brand' but I would think at least
the BC would fit that decsription.


Though as expected the level was very low, at the 2vRMS 5kHz from my sig
gen, it needed the cap to be against the ear, but it was clearly there.


What is the o/p impedance of your sig gen? 2.2microF at 5kHz is about 15
Ohms if my fingers just pressed the correct buttons on my hand calculator.
Implies a reactive level of over a Watt if you really were applying 5v rms.

I just measured it, somewhere around 65R, off load it was giving 8v RMS.
I said with the cap in place, it was producing about 5v P/P on a scope
trace, or about 2v RMS.


If I understand the ClarityCap papers correctly, you'd need to find the
mechanical resonance of each cap to get a peak level of vibration. So 5k
might not give as large a response as some other frequency.


Yes, but I was just trying to test the assumption that no cap would
produce any noise, having found that some do under simple to achieve
conditions, there is scope to perform more detailed tests.

I wonder if something like a strain gauge attached to the cap would be
the best way to measure any vibration.

--
Nick

Do all capacitors sound the same.
 

"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."

Do all capacitors sound the same.
 

"Nick Gorham" wrote in message


I just tried the experiment on a few caps I have to hand.
The ones that produces a sound when driven by a sig gen
were a BC 368WKT 220nf, Acotronics MKP 47nf and a 2.2uf
ClarityCap SA. Ones that I tried that didn't prduce any
sound I could hear were from Solen and Mundorf.

Two problems:

(1) The stated problem seems to be not that the capacitor produces sound
(it's someplace inside the bowels of the enclosure) but that operating in a
sound field causes the capacitor's operation to be modulated by the sound
field.

(2) If you're going to test capacitors, it would seem that you would want to
test them as they are used. IOW with the kinds of voltages, currents and
sound fields that one sees in a loudspeaker.

Though as expected the level was very low, at the 2vRMS
5kHz from my sig gen, it needed the cap to be against the
ear, but it was clearly there.

Note that the output stages of some SS amps produce audible sounds related
to the signals that they are amplifying.