What value cap to bypass power supply cap?

Thanks! That was very helpful.

Dracule1, Take into consideration that bypassing large inductive electrolytic caps with small non-inductive cap crates parallel resonance circuit that will ring in response to rapid current changes. Designer did not put them for a reason.

I would speculate that you might not like the result but it isn't very expensive to try.

Kijanki, thanks for that info. However, all my power supply caps are film caps which according to the manufacturer have ESR and inductance which are a fraction of electrolytic. I know the ESR is 1 mOhm at 10 kHz, but I don't know the inductance. Are film caps considered to be inductive enough to have parallel resonance?

Dracule1, I don't think so. Looks like you got great stuff there. I second 1% minimum recommendation.

Davehrab and Kijanki, I asked an experience electronics engineer who has written papers on bypass capacitors. His response to your statement:

"As you can see from above, the self-resonant frequency will vary depending on the value of capacitor used and its inherent inductance. The physical construction, size and value of the capacitor will determine the amount of inductance. So in order to maintain maximum ripple rejection across a large frequency range you’ll need to add additional (smaller value) capacitors in parallel with large value caps."

was this:

"Yes, theoretically the self resonant frequency of the capacitor can affect the ripple rejection of the power supply filter. HOWEVER, you have to remember that the amplitude of the harmonics of the rectified AC power decrease with frequency so at a few kilohertz and above, the power supply noise is pretty small."

He recommended bypassing the amplifier end (using 0.1 microF bypassed on 10-22 microF bulk bypass cap) and directly across each power supply caps (using 0.1 microF bypass caps).

Not trying to start any flames here. Just trying to learn the differing points of view on this subject.