Power help

I think those PC backup power supply units sound pretty bad. Why not try it with and without the UPS?

A component's power supply should ideally be indifferent to the source of the power within certain margins. If things between the back of the box and the power plant make a difference, that's a basic failing of the power supply. I'd pour my money into making the power supply more resistant to minor variations in the power source before trying to doctor the problem with expensive Band-aids. 

The APC UPS puts out terrible, square wave power that’s full of noise that even the best linear power supply can’t clean up. The APC also doesn’t cutover cleanly from utility power to battery power.  You could go with an on-line pure sine wave output UPS like the Eaton 9130. The only downside of the Eaton 9130 and other high quality output UPSs is they have noisy cooling fans, so they need to be located outside of the listening room. 

@kosst_amojan your message is contradictory. Re-engineering a power supply will be nearly impossible for most people who don’t have the knowledge or means. Even for people who have the knowhow, the cost of upgrading power supply upgrade parts and real estate limits inside the components is another limiting factor. It is infinitely better to solve the problem at the source by adding a good UPS or at least a good power conditioner.