[sdiy] SSI2144 filter caps

[Mattias Rickardsson]

On 12 September 2017 at 21:38, Ingo Debus <igg.debus at gmail.com> wrote:
>> Am 12.09.2017 um 13:46 schrieb Mattias Rickardsson <mr at analogue.org>:
>>
>> They
>> also have a strong voltage dependency, which is not only a problem if
>> there is a DC offset, but it immediately distorts all signals that are
>> non-zero. Which useful signals tend to be. ;-)
>
> If voltage dependency is the only problem, can’t you just use caps with a higher voltage rating, say 100 volts or more? Probably these are still smaller than film caps.

I'm not sure if you can, since the capacitance seems to fall
identically regardless of voltage rating:
https://www.maximintegrated.com/en/images/appnotes/5527/5527Fig01.gif
If this picture speaks the truth, it seems to be the physical size and
the material that makes the difference. X7R in the biggest possible
package gives the lowest distortion among all X7R and X5R caps.

/mr