Bipolar Caps for decoupling?

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Can you use non-polar electrolytics as local (power supply) decoupling capacitors?

I've searched and found only threads about polar electrolytic caps as coupling caps...

My power amp's input diff-amp circuit specifies a 100uf/50v polar electrolytic, but all I have are some (high quality)220uf/50v non-polar electrolytics on hand.

Will these work ok?

If no, then why not ?

-Joe
 
The nonpolar will work, they are capacitors.
You have paid a premium for the nonpolar capacity, that does not get used in this instance. This results in poor value.

Polar capacitors designed specifically for decoupling duty also sell at a premium, but in this case the extra performance is of some benefit. Maybe better value?
 
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Polar capacitors designed specifically for decoupling duty also sell at a premium, but in this case the extra performance is of some benefit. Maybe better value?

Thanks Andrew, but what benefit, if any?

Does this mean that (in my case) Nichicon Muse polar caps will outperform the more expensive Muse NP types? Enough to warrant replacing these NP types?

While I'd spend a bit more for better results, are the NP's in any way inferior?

Anyone??

-Joe
 
Hi Joe!

I have done this before and they worked fine; however, I don't know if they are any better/worse than polars in this application.

There's quite a bit written about using Black Gate N-series (nonpolar) as decoupling caps, so I don't see where there should be any problems using the Nichicons.

Maybe Andrew can elaborate on what benefits a high-grade polar cap would give (maybe related to ESR)?
 
Continuing on the same tangent, I recently came across a metallised polyster film capacitor series that is in standard production which goes as high as 470uF @ 63V. They're certainly wouldn't be cheap, and they're obviously quite chunky, but I guess they would definitely represent and interesting alternative to electrolytics....
And you'd only need 21 of them in parallel to form a 10,000uF @ 63V PSU cap !!!!
 
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