Use computer UPS to power source, good idea?

There are lots of computer UPS that are capable of delivering hundred of watts for hours at fraction of the cost of a good power filter. Not planning to use it on power amp or power hungry devices, would this idea be viable on source, phono stage, or even pre amp if power rating is within the spec? Has any one tried it? One draw back I can think of is slight reduction in dynamic, but does it?

Before I go drag one home from a store, want to hear from someone who has tried it and hopefully with good results.