PSU Smoothing Caps (how many?)

MWP · 6th September 2004, 01:53 PM

Hi all,

Im going to start building my new amp tomorrow and am trying to work out what total capacity of PSU smoothing caps ill need.

Ill be using 3 * 300VA 25-0-25 torids (=900VA total) to power 6 channels of 2 * LM3886s bridged per channel.

Is the general rule in here of 2*1000uF caps per amp IC (=24,000uF total in this case) enough?
Or will i be needing more than this?

Thanks.

Nuuk · 6th September 2004, 02:53 PM

If some of those channels are just supplying a bass speaker or sub, then you could add something like 2 x 10,000 uF for those channels.

MWP · 6th September 2004, 04:11 PM

Hmmm, ok.
Well ive got 2*470uF on each amp IC on the PCB already.

So, say another 22,000uF on each rail would do it?

JhonDoe · 7th September 2004, 04:57 AM

Quote:

Well ive got 2*470uF on each amp IC on the PCB already.

are 2*470uf per chip is enough?? I thought 2*1000uf per chip is the recommended? what will be the effect of this lower caps in sound quality?

6th September 2004, 01:53 PM	#1
MWP diyAudio Member Join Date: Oct 2002 Location: Adelaide, South Australia	PSU Smoothing Caps (how many?) Hi all, Im going to start building my new amp tomorrow and am trying to work out what total capacity of PSU smoothing caps ill need. Ill be using 3 * 300VA 25-0-25 torids (=900VA total) to power 6 channels of 2 * LM3886s bridged per channel. Is the general rule in here of 2*1000uF caps per amp IC (=24,000uF total in this case) enough? Or will i be needing more than this? Thanks.

6th September 2004, 02:53 PM	#2
Nuuk diyAudio Member Join Date: Feb 2003 Location: Somerset, SW England	If some of those channels are just supplying a bass speaker or sub, then you could add something like 2 x 10,000 uF for those channels. __________________ The truth need not be veiled, for it veils itself from the eyes of the ignorant.

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6th September 2004, 04:11 PM	#3
MWP diyAudio Member Join Date: Oct 2002 Location: Adelaide, South Australia	Hmmm, ok. Well ive got 2*470uF on each amp IC on the PCB already. So, say another 22,000uF on each rail would do it?

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