They use big toroidals, rectifier , and big cap for a reason.. That is by far the cleanest power chain you can get..
Anything digital, especially digital rectification gets complicated and potentially noisy... unless it's TESTED at the output stage with professional audio system analyzer, Whatever a HUMAN, proclaims to hear is all a bit weeble-wobble
Unless your house is just too old w/ severe brown out or surge issues, Can't imagine a g4m3r ups product sounding better than a properly designed amp straight into the wall..
ups product--- untested
amp/ receiver --- Tested. (big box brands, none of that weird artisan EE student maker crap) hahaha..