Sorry for the double post, but I wanted to create a new thread for this since the previous thread was very old (2005). Please read this article: http://en.wikipedia.org/wiki/Super_Audio_CD#Audible_differences_compared_to_PCM.2FCD There appears to be no audible difference between Redbook CD at 16bit/44.1kHz PCM and SACD 1bit DSD at 2.8224MHz under double-blind experiment conditions. The same study also cites that there are no audible differences between SACD and HDCD at 24bit/174.6kHz PCM. Based on the above, SACD is a marketing gimmick and so is HDCD. There is no scientific literature with controlled double-blind conditions to prove otherwise. If you do have information about a formal scientific double-blind study that says otherwise, please share it!