Electret micriphone DC blocking capacitor polarity

[jimqbaum]

Why is the DC blocking capacitor for the output to the amplifier stage from an electret microphone shown on some schematics as polarity dependent?

 

[sky_123]

If the DC voltage on one side of the capacitor will always be higher (or always lower) than the other side (i.e. due to
bias resistors) then for cost reasons (often lower-cost) electrolytic is used rather than an unpolarized cap which often can
be more expensive for large values.

 

[jimqbaum]

Thanks for the prompt reply. This makes the best sense to me. I have tried different types of caps and have seen no real significant difference.
I am relatively new to electronics and it is overwhelming sometimes to try and reason through the many different versions of schematics for the same desired result.
I just got my hands on an oscilloscope and am getting warmed up to using it. The scope sure helped me with the comparison of caps.

 

[sky_123]

By the way, although books usually have good circuits, some websites have some really bad circuits, which confuse more than help comprehension. For some good basic circuits (it's apparent that the author(s) tested them), then this is a good link. If you've got a scope, then this helps understanding loads. 'The Art of Electronics' is a slightly expensive book, but is excellent for practical information with math, but not too much math at all. Most people highly recommend it. I donated my copy to someone, but I regret it now : ) Just can't bring myself to spend that much money on the book again, but I have a feeling I will bite the bullet and do so soon.

 

[jimqbaum]

Thanks I will check into the book. Oh, and yes, I've spent many and hour in the site that you have linked. Great guy with volumes of information if he would just stop jumping around and stay on point.