They do not use HIGH capacity capacitors ..IF you use a High capacity cap you have the chance of Blowing thing up..its not like it store only a small amount and slowly discharges that energy its a all or nothing thing..6000uf is a small cap..a 20,000uf cap will cook ur stuff..they do not filter any noise.. you need a separate circuit to do that..
You either know your electronics or you should just not POST..your telling people things that will hurt them and their electronics..
Here is a noise filtering circuit..