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In a customer review of this amp there seems to be a large electrolytic capacitor connected to its power supply (images below) for decoupling purposes. It is visible from the first image that the cap is accompanied by blocking diodes.

It would make no sense for them to be part of a rectifier as the amp operates with AC voltage. So my question is how are they set up with the capacitor so both decoupling and AC voltage to the amp can be accomplished.

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marked as duplicate by Community Mar 30 '18 at 17:18

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This is known in engineering circles as an FGC, or 'very big capacitor'.

Depending on what the shortcomings of the power supply are, it's to lower its output impedance or reduce its noise or ripple.

The value is not too important, and is generally in the 1000s of uF.

  • \$\begingroup\$ "it is widely known in narrow engineering circles" - this is a good one. +1 \$\endgroup\$ – Ale..chenski Mar 30 '18 at 18:33

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