When is it okay / desirable to use tantalum caps?

[piltdownman]

Can I use them in place of regular (non polarized) caps?  If so, how do you orient them?  I thought about it last night while I was building a Son Of Clay Jones.  It uses a 1u cap and i just happen to have a couple 1u tantalums.  Just wonderin'  Thanks

[Frank_NH]

In my recent ROG Thunderbird build, there are several caps in the power section which are prescribed to be tantalums and so I used them there.  Otherwise, I avoid them unless space is at a real premium.  In orienting polarized caps, you need to make sure the + side is on the higher voltage side of the two points in the circuit to whihc is being connected.  Sometimes that isn't obvious, and you may need to measure the voltages to confirm and switch the orientation appropriately if need be.

[piltdownman]

Thanks.  The 1u chiclets can be unpleasantly large but they fit fine in this instance.  I just always got the impression that folks thought they had some special mojo or something.  But people are always saying that about something!  Thanks for the explanation, I appreciate it.

[motterpaul]

I agree - those 1u caps are ridiculously large.

Here is a good discussion on this topic:

http://www.eevblog.com/forum/projects/whenwhy-%28not%29-to-use-tantalum-capacitors-pros-cons-alternatives/

[piltdownman]

Interesting.  I understood around 20% of what was discussed, but the gist is that there is no real advantage aside from size, right?  As long as the layout is taking the size into account - like Mark's Son of Clay Jones, it's ok.  It has 3 220n's as well that aren't all that svelte either, but they all fit fine.  All I have are a few 1u tants, so it's not a big deal.  The problem is that I can't remember why I bought the in the first place.  Whenever Tayda has a sale, I tend to just drunkenly click all over the site.

[Travis]

"Whenever Tayda has a sale, I tend to just drunkenly click all over the site."

lol this is exactly what I do. I go for the pots, end up with a giant bag of stuff.

[rocket88]

sigh i'm just as bad. i think my last order started with ordering 10 or all the pots i keep around, next thing i know i have almost $400 in parts in my cart . got to say though that 20% off makes making big orders easy to create, and cover shipping and then some. i'm just as bad on ebay some times. i just received 150 3pdt switches, when i really only wanted 100, but the price was too good. i think i'm good to get building for sale lol.

[induction]

The only pedal-related situation that I know of where tants are actually preferable is power filtering, especially on voltage regulators, because the have low ESR. People often avoid them in the signal path because they can add distortion, but I don't know if you can actually hear a difference, especially in a distortion pedal.

Caution: They are extremely offended by reverse polarity, and will often quite literally explode in retaliation.