Following on from this thread: Arduino Forum
I followed the link to: SparkFun MP3 Player Shield - DEV-12660 - SparkFun Electronics
And then: http://www.sparkfun.com/datasheets/Widgets/MP3Trigger/vs10XXan_output.pdf
In that document it mentions putting in a 10 ohm resistor in series with a 10 nF capacitor, from left/right signals to ground, to suppress ESD.
What it doesn't mention is, what rating capacitors would you use there? Since you are trying to handle 8 KV ESD, I presume you don't try to find 8 KV capacitors. Would 50V do? Or am I missing something?
You have to think in "charge" instead of "voltage".
A high voltage spike will be suppressed because it's charge will flow into the capacitor.
The voltage of the capacitor will probably not rise above 5V.
So a normal 10nF of 50V is okay.
I used a resistor and capacitor in series many times as spark-suppressors to prevent spark with relay contacts or with bells like these: GCSE PHYSICS - How does an Electric Bell Work? - Electromagnetism - GCSE SCIENCE.. For the bells I used 47 ohm and 100nF.
Would 50V do?
Yes, but even lower would work as well.
If you think about it, if it were a problem, capacitors would be subject to static handling damage like semiconductors and they are not are they.