AHPCS10 Power Conditioner : No noise w Guitar/Audio Interface any longer

I have a basic 1st gen Focusrite Scarlett interface with a guitar plugged into it. For ages I couldn't understand why some people on YouTube have managed to get good tones with various Amp Sims, my setup was just too noisy and fuzzy. I've tried with a DI Box, took care of clipping, nothing helped. I've installed this power conditioner and boom, the noise was gone. And I'm not talking about placebo effect: my girlfriend instantly noticed the difference without me giving her heads up. It's day and night.

In a nutshell: if you're living in an old building with shitty electricity, have a guitar and you'd like to use it with an audio interface only, you need to buy this thing.