Can someone please tell me what this component is doing?

[Guitarfreak]

Or recommend me something where I can read up on the subject matter involved here.  It is C15, the 220uF electrolytic cap that goes from power supply to ground.  I am modding my Muff to Ram's Head specs and the Ram's head schematic I am using doesn't have this component present, so what would removing it do?  Actually the other electrolytic cap and 2 100 ohm resistors are not in the Ram's head schematic either.  Something to do with battery drain?  Thanks.

http://img262.imageshack.us/img262/40/bigmuffusareissue3fd.png

[sjaltenb]

I'm guessing power filtering? But im not very good at this type thing.... DONT take my word for it  

Hey, i was right!

[theehman]

Just power filtering.  It won't affect anything to leave them in.

[Mark Hammer]

...and if you use an adaptor (something rarely employed in the old days), you will be glad you left them in.

[Guitarfreak]

I've noticed that some pedals are using 100uF caps instead of 220uF that are in my pedal.  This more than doubles the cutoff point.  Should I do this?  And why does my unit have two coupling caps and not just one?