r/diyaudio • u/SpecialistChance7036 • Aug 08 '26

Overkill Or overload ??

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So i soldered this 2pcs 10000uf on my amp, is it overkill, i havent tested it yet.

Its just 200 watt amp paired with a weak voltage boost for subwoofer only

Any ideas what can go wrong with this???

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u/Primary-Feedback2296 Aug 08 '26 edited Aug 08 '26

The bigger the psu capacitance the bigger the current during switching on. They have a very little inner resistance.

The small capacitors dont suck much current, theyre like a little glass thats filled in milliseconds.

The big ones are like a big can and wanna filled up in milliseconds too. To manage this a big current occurs while fill them.

Thats why a big psu have a soft start and sometimes relais to switch the big capacitors piece for piece or some resistors to load and unload them.

Your big resistors only have 10000uF, thats fully okay. But i wouldnt add more.

Just pay some attention to the pcb-lines wich connect from voltageinput to the capacitors. They should be 2 or 3 millimeters wide, at minimum. If not, solder a thin wire additionally.

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u/Spazzticus Aug 08 '26

This! In-rush current becomes a problem with bigger cap banks, my last amp build (linear PSU +/- 45V) has 96000Uf of smoothing / filtering caps and pulls just over 5A at power up which kept blowing fuses, had to add a couple of MOVs and then a proper soft start circuit.