Electrolytic VS. Tantalum

[Mike Nichting]

Hi all,
can I use Tantalum in place of electrolytics all of the time??  Would there be an advantage to this?? I have heard more than once that it is best to keep electrolytics out of a circuit when you can.

Thanks all,
Mike N.

[petemoore]

Electro's are know to dry out.
 Tantalums are more stable temperature wise.
 The hand me down story [I believe] that they use tantalums for everything cap related on NASA Space vehicles

[Peter Snowberg]

Dry tantalums have a much longer life span, but they don't like reverse bias at all. They degrade the signal less than aluminum electrolytics and the way they distort things is quite different than electrolytics.

If you can satisfy the bias requirement, by all means use them. They are superior in just about every way.

Take care,
-Peter

[Doug B.]

Dry tantalums ... degrade the signal less than aluminum electrolytics and the way they distort things is quite different than electrolytics.

Here's some interesting empirical data with scope traces of capacitor distortion:

 http://members.aol.com/sbench102/caps1.html

Note that this is primarily a vacuum-tube audio site, and it might not be completely generalizable to MI effects (we often LIKE distortion).  Still, interesting to see what capacitor types do to the signal.  

(Don't miss the rest of that article -- it talks about films and ceramics!)  

- Doug B.