One thing that has changed since the 90's is the explosion of devices that make up the average home. I'm sure there are papers out there that document how much the noise environment has changed.
Who Tried Power Conditioners Over The Years and No Longer Use Them Today, Any Why?
Been thinking back to when I started in Audio and how good the system sounded with no power conditioners or fancy power cords. Then in the '90s slowly they both became a huge profit market for stores and manufacturers of them. If you used one on front end gear only or whole systems I will be interested in your real-world experience you could share with us all. I have a few so I am not against them, but I do at times have questions.