Ejlif, thanks for info. I am very hesitant to put enhancers on CDs because of various fads in the industry. In the late 1980s they had these self adhesive thin plastic rings that you applied to label side to "stablize" disc during rotation, and of course the green pen craze of the early 1990s. Not only do these treatments make discs unsellable in the aftermarket, if you later decide it doesn't sound so good you often can't reverse the process. I purchased some duplicate CDs so I can do some careful comparisons to untreated original, I will be trying "auric illuminator" and "optrix" and now I guess I can try some "DiscSolution". It will have to be a noticable improvement though before I risk appling to my valuable CDs, as I say I am very reluctant to alter stock CD.