Modern power supplies, which are properly designed, take AC from your house mains, transform it, regulate and filter it before the audio gear uses it.

Unless you live in an area that has extremely poorly regulated AC, there is NO need for this extra filtering of the APC.

But, if you have a "spare" one, why not use it?

If you really are hearing a difference, then, I would agree, something else is going on with your AC mains.