Inductive PSU, SMPS and PI filters

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Inductive PSU, SMPS and PI filters - help needed

Hi -
I need some advice regarding this PSU I have made from an old ALOIA Inductive PSU. I have a pair of Temple Audio Bantam Gold mono blocks (chip/class d amps) that run off some pretty cheap 18v 3a SMPS. There are some very nice looking linear PSUs out there that don't cost the earth but enough to stop and make you think. I have had the Aloia knocking around for ages and wanted to put it to use. So essentially I have run each SMPS through it's own inductor and then onto the amps - the result is stunning. However, it was pointed out on another forum that I am a capacitor short of a PI filter - and by adding some large caps after the inductors would be beneficial.
I have read adding caps after and SMPS before the load can make it unstable - but because I have the inductors in the way it's ok. Here is my dilemma - my electronic theory/skills are pretty basic. The amps have/had x 2 Nichon 2200uf 25v caps already installed (I have swapped these out for 2200uf 35v BGates) - so would adding in large caps after the inductors improve on anything? I'm conscious that I must attach the + of the cap to the +vdc from the inductor and the - of the cap to ground / problem is I don't have a ground (most ac SMPS devices don't use earth here in Greece) - I only have + and - out of the SMPS - I do have an earth/ground from the mains connection before the SMPS (but it's not used anywhere not even by the SMPS) should I use this? if I do am I likely to blow something up?
Based on the amps/PSU rating 18vdc (they draw around 2A I have read - PSU is rated 3A) what would be a good spec to aim for the possible storage caps - is it a case of the bigger the better:)roll eyes:)? any guidance would be very welcome
Kind regards
Stu

Here is a photo of the PSU -
An externally hosted image should be here but it was not working when we last tested it.
 
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