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