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What value cap to bypass power supply cap?

Is there a way to calculate the value for a bypass cap to parallel a power supply cap? To bypass a coupling cap or crossover cap, I've heard you should use 10 to 20% of the value cap to be by passed. For example, you should use 0.5 microF cap to bypass a 5 microF cap. However, I've heard you should use a standard 0.1 microF cap to bypass power cap, no matter the value (I have power supply caps up to 760 microF).
dracule1
dracule1 OP
1,085 posts
 
Sequence of bypass caps to cover broader range of filtering from several hundred kHz to 10s of MHz. They will be at the amplifier end as you recommend.
almarg's avatar
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almarg
9,670 posts
 
I agree with Kijanki that using three or four different value caps seems like overkill. Admittedly we are going on instinct, because there are many variables and unknowns involved, relating to the design of the amp, the characteristics of the capacitors, and the characteristics of the incoming AC. And because issues involving noise tend not to have a great deal of predictability.

My vote would be for at most two values, either 0.1 uf or 1.0 uf or both.

Best regards,
-- Al
dracule1 OP
1,085 posts
 
Thanks. Will try with fewer caps to keep things simple.
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