Hey I have the rainbow foil. He had a free offer; you could get enough magic foil to do ten cd's and a small strip for say a pre-amp. I still have it in a bag except I did try it on a cd. Who knows; it certainly didn't make the cd sound any worse; maybe thats all we can hope for. I do hear some different sound with interconnects though; but there at least we have electrical properties of the wire that could effect sound. .