Jamicon WL-R caps "not suitable for audio"

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Why does the WES catalogue advise that Jamicon WL-R miniature low ESR
capacitors are "not suitable for audio"?

Here is the datasheet:
http://www.wescomponents.com/datasheets/WLr.pdf

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Re: Jamicon WL-R caps "not suitable for audio"

:Why does the WES catalogue advise that Jamicon WL-R miniature low ESR
:capacitors are "not suitable for audio"?
:
:Here is the datasheet:
:http://www.wescomponents.com/datasheets/WLr.pdf
:
:- Franc Zabkar


Franc, I see nothing on the WES data sheet or the manufacturer's data sheet
http://www.jamicon.com.tw/WebApplication2/pdf/capacitor/WL.pdf which advises
"not suitable for audio". The WL is specifically designed as a 105C low
impedance type for use in small smps but that doesn't mean it can't be used in
audio applications.

Looking at any of the Jamicon data sheets here
http://www.jamicon.com.tw/cappicseach.aspx I can't see any which specifically
recommend suitability for non-suitability for audio use, not even in their
general purpose types - yet, we all know that they are used for audio apps.

Re: Jamicon WL-R caps "not suitable for audio"
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    They're designed for circuits which put high frequency ripple
current through them, so audiophiles will instantly notice an irritating
'shrill' element in the sound if they're used for audio.

Bob


PS - I was being sarcastic.





Re: Jamicon WL-R caps "not suitable for audio"

:> wrote:
:>
:> :Why does the WES catalogue advise that Jamicon WL-R miniature low ESR
:> :capacitors are "not suitable for audio"?
:> :
:> :Here is the datasheet:
:> :http://www.wescomponents.com/datasheets/WLr.pdf
:> :
:> :- Franc Zabkar
:>
:>
:> Franc, I see nothing on the WES data sheet or the manufacturer's data sheet
:> http://www.jamicon.com.tw/WebApplication2/pdf/capacitor/WL.pdf which advises
:> "not suitable for audio". The WL is specifically designed as a 105C low
:> impedance type for use in small smps but that doesn't mean it can't be used
in
:> audio applications.
:>
:> Looking at any of the Jamicon data sheets here
:> http://www.jamicon.com.tw/cappicseach.aspx I can't see any which specifically
:> recommend suitability for non-suitability for audio use, not even in their
:> general purpose types - yet, we all know that they are used for audio apps.
:
:
:    They're designed for circuits which put high frequency ripple
:current through them, so audiophiles will instantly notice an irritating
:'shrill' element in the sound if they're used for audio.
:
:Bob
:
:
:PS - I was being sarcastic.
:
:
:

Bob, I know that you wouldn't believe such things would result from using the WL
in audio apps. However, it is just as well that you included your final remark
otherwise someone from the golden ear brigade might just believe it was true.

Re: Jamicon WL-R caps "not suitable for audio"
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WL
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G'day Ross,
    Yeah, I thought I better make it clear that I wasn't serious, just
in case someone believed it! :)

Cheers
Bob


Re: Jamicon WL-R caps "not suitable for audio"
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Maybe its because they aren't expensive enough  ;)
Obtaining and processing the snake oil required is very labour (left
hand) intensive. :)

Re: Jamicon WL-R caps "not suitable for audio"
put finger to keyboard and composed:

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I notice that elsewhere WES suggest that low leakage caps (ELR and
EMRL) are the capacitors of choice for audio pre-amp stages. These
have a leakage current of 0.3uA whereas the WL-R caps specify 3uA.
However, the low impedance general purpose EXR caps with a leakage
current of 3-4uA are stated to be OK for audio. <shrug>

Of course over the page are "hifi" rated 10,000uF and 15,000uF caps,
whatever that means, but we won't mention those. :-)

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Re: Jamicon WL-R caps "not suitable for audio"
On Feb 5, 8:38 pm, Franc Zabkar
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Well, for example in ceramic capacitors with dielectrics like Z5U that
is the same as Y5V, have the characteristic that the capacity is ONLY
and ONLY achieved under bias. That meant a 1uF ceramic capacitor is
only 100nF at 0.2V DC bias and ~1uF at 10V bias, etc. In audio
applications you use capacitors in various functions. In power supply
you don't care about such properties, because you always try to run at
full rated voltage of the supply. However if you were to use such
capacitor in oscillator or filters, you would get very large nonlinear
distortion. I personally tried some small, cheapest ceramic capacitors
(I think Z5U dielectric or similar) and I could tune oscillator
frequancy depending on capacitor bias voltage with one finger on
capacitor terminals and the other touching supply or ground. It was
fun.

Now back to your question. Electrolytics should not have much
nonlinearity at all. Maybe the double-layer capacitors before
activation, or multi-electrolyte type formulations could have more
exponential characteristic than is usual. But is is only a remote
possibility. Maybe the question was whether you want also to use it as
a bipolar non-biased capacitor. Soem 10 years ago I used electrolytic
capacitor in an application which required only alternating current
and of course the electrolytic capacitor - being only low current
UNIPOLAR type smoked the electrolyte out. That is what are BIPOLAR
electrolytic capacitor for. You ask WHAT is the difference? The main
is the electrodes, being of aluminium foil, one is oxidized and one
isn't. Bipolar capacitor has both electrodes oxidized (as far as I
remember, weak, weak memories :-) ). Think about it briefly, would you
use an electrolytic capacitor with reversed polarity? Of course
not :). And that should be the most obvious matter on use of unipolar
electrolytic capacitors in audio. Oh, forgot to mention what happens.
Electrolytic capacitors have LIMITED lifetime. Wrong polarisation will
result in much faster electrode corrosion and will greatly shorten the
useful life. In audio path you want to use capacitors that will last
and not change their parameters over time. In switched power supplies
the capacitors have very short life, some will become useless in years
and develop gas pressure from decomposition and heat inside. reversing
polarity would much accelerate that.

If you want to use it under biased conditions of in a power supply,
you don't need to worry about capacitor being suitable for SMPS or
AUDIO, it only needs to be able deliver the current and not overheat
during that.

Re: Jamicon WL-R caps "not suitable for audio"
On Wed, 20 Feb 2008 14:50:51 -0800 (PST), snipped-for-privacy@gmail.com put finger
to keyboard and composed:

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WL-R caps are polarised. The only time I can imagine a "bias" problem
is when coupling the inputs and outputs of two items of audio
equipment, but that would affect all non-polarised electrolytic caps,
not just the subject ones.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

Re: Jamicon WL-R caps "not suitable for audio"
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this is exactly backwards. 5% rated voltage gives about 10% drop in C.
50% rated voltage is more like 70% drop, full rated voltage closer to
90% (Z5U and Y5V are a bit different, but both are horrendous).

in a given footprint I have yet to find a Y5V/Z5U cap that gives more
capacitance than X7R when running at 70% rated voltage.

and their temperature behaviour is appalling, too.

I first "discovered" this circa 1993, when a SMPS output with a constant
load had ~ 30x more ripple than I expected. after confirming the load, I
went and looked hard at the cap, and noticed the voltage derating factor
(25V cap, 20V supply). ISTR it was a 1uF Z5U, and I ended up with about
30nF at 20Vdc, 60C ambient. verified several ways: solder wires onto
cap, stick on LCR bridge, heat with hot air - wow! add pullup resistor
do DC supply, then put 20uF film cap in series with LCR bridge, and
adjust V - wow! replace with 1uF film cap in circuit - ripple spot on.
In the end I used a 220nF X7R and the ripple went *down* by 8x

I have not used such a cap since then. And in fact specify in big
letters on the sch "NO Z5U/Y5V caps" - in addition to specifying the
dielectric in the BOM.


In audio
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until of course you notice you havent got anything like as many farads
as you thought.


However if you were to use such
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X7R has about 15% drop in C at rated voltage IIRC, which makes it great
for SMPS, but still shite for these type of circuits. the tempco is
similar, about 10% drop at Tmax.

they all have Barium Titanate & Titanium Dioxide in them (along with
other goodies), which are very piezoelectric. whack your filter/osc with
a pencil, and see the fun.

I have seriously thought about using them as $0.001 temperature sensors.....

it would be fun to make one into a microphone. although the sensor for
an electronic drum would be easier - use 0.8mm PCB, and whack it with a
drumstick....


NP0 is the best ceramic dielectric. ~ zero tempco, and flat with applied
voltage. pretty much every smt cap below 1nF is NP0, but its hard to get
them above 10nF or so. These are great for sensitive analog circuits.

I have seen a 100uF 200V NP0 capacitor with ultra-low ESL (~ 1nH IIRC).
designed for smps use in satellites. and US$2/uF.

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not at all - spot on.

  Think about it briefly, would you
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they look a bit like crappy diodes. hence getting unhappy and/or expiring.

  And that should be the most obvious matter on use of unipolar
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only in crappy smps. decent smps design is all about cap life (and
thermal cycling of semiconductors).

alas almost all smps in consumer eqpt are crappy :(

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indeed. nichicon & rubycon have some nice apps on figuring out how long
a cap will live.

Cheers
Terry

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