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Hi,<br>
<br>
Two things. First, some circuits need blocking caps because the
chips input pin has a DC bias on it. Second, if you want to protect
from fast transients on the input, use a 100pF cap to ground after
the input resistor. This will take care of most hits including ESD.
<br>
<br>
--Tim (recovering EMC engineer) Ressel<br>
<br>
<div class="moz-cite-prefix">On 2/6/2016 1:24 AM, Mattias
Rickardsson wrote:<br>
</div>
<blockquote
cite="mid:CAP92RBX_TqgRFO+JyeFFnTc0jx1gHp16Qba+GXfOkyNX8m7fMw@mail.gmail.com"
type="cite">
<p dir="ltr">Another capacitor question popped up:<br>
What's your view on having electrolytic caps right at the input
of an audio device in order to block DC and/or protect the
circuit?</p>
<p dir="ltr">I always have a smallish resistor and dual schottky
diodes connected towards rails at the inputs, and I hope this
will protect from most voltage spikes. Does a cap really add any
protection here? The DC issue can be taken care of later in the
signal chain, and avoiding input caps saves cost, space, and
possibly audio quality.</p>
<p dir="ltr">/mr - with golden [tinitus shower] ears<br>
</p>
<p dir="ltr">Den 3 feb. 2016 8:01 em skrev "David G Dixon" <<a
moz-do-not-send="true" href="mailto:dixon@mail.ubc.ca"><a class="moz-txt-link-abbreviated" href="mailto:dixon@mail.ubc.ca">dixon@mail.ubc.ca</a></a>>:<br>
><br>
> I've read all these recapping posts with interest, but I
gotta say, I avoid using electrolytic caps except for power rail
decoupling purposes. I never design them into actual circuits
(and I've never built my own power supply). Same with tants.</p>
<br>
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<br>
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</blockquote>
<br>
<pre class="moz-signature" cols="72">--
--Tim Ressel
Circuit Abbey
<a class="moz-txt-link-abbreviated" href="mailto:timr@circuitabbey.com">timr@circuitabbey.com</a></pre>
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