Review on PAC SNI 135 Ground Loop Isolator by Anthony Bandzz

My situation: I have a ground loop problem caused by something internal in my new PC (Asus) that I don't understand and will not understand. Problem: USB ports are noisy, analog ports are noisy; Front, back, all other hardware disabled including keyboard and mouse. All of the equipment's power cords are connected to a very expensive sine wave UPS which is plugged into a single wall outlet that has been found to be OK (polarity and grounding). The problem is computer endemic, I can't reproduce it on my old PC (alienware), x2 laptop or x3 phone. old studio monitors that I now use as monitor speakers. Not exactly an "audiophile" ideal setting, but good enough for everyday listening. That's what I think. This thing definitely removes ground loop noise by 100%. Very impressive. Total silence in line. In a listening test with "Train Song by Molly Cole" (FLAC): Without PAC, I hear the ground loop to the music like a screwdriver in my ears. With PAC the ground loop is gone. Other than that, I can't tell any significant difference in sound quality. I chose this song based on other reviews that said this PAC destroys high-pitched sounds, the song selected has high-pitched sounds that are almost inaudible on lower speakers. Based on my sound perception, I believe the PAC does what it's supposed to do without significantly sacrificing sound quality. For me, this was a cheap solution to a difficult problem that I felt the DAC I was using should have solved. Gear used: KRK Rokkit 8, KRK 12sHO, Campfire Audio Solaris, Dragonfly Cobalt DAC.